clang  7.0.0svn
CGExpr.cpp
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1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit Expr nodes as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13 
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"
30 #include "llvm/ADT/Hashing.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/Intrinsics.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/MDBuilder.h"
36 #include "llvm/Support/ConvertUTF.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Transforms/Utils/SanitizerStats.h"
40 
41 #include <string>
42 
43 using namespace clang;
44 using namespace CodeGen;
45 
46 //===--------------------------------------------------------------------===//
47 // Miscellaneous Helper Methods
48 //===--------------------------------------------------------------------===//
49 
51  unsigned addressSpace =
52  cast<llvm::PointerType>(value->getType())->getAddressSpace();
53 
54  llvm::PointerType *destType = Int8PtrTy;
55  if (addressSpace)
56  destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
57 
58  if (value->getType() == destType) return value;
59  return Builder.CreateBitCast(value, destType);
60 }
61 
62 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
63 /// block.
65  CharUnits Align,
66  const Twine &Name,
67  llvm::Value *ArraySize) {
68  auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
69  Alloca->setAlignment(Align.getQuantity());
70  return Address(Alloca, Align);
71 }
72 
73 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
74 /// block. The alloca is casted to default address space if necessary.
76  const Twine &Name,
77  llvm::Value *ArraySize,
78  Address *AllocaAddr) {
79  auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
80  if (AllocaAddr)
81  *AllocaAddr = Alloca;
82  llvm::Value *V = Alloca.getPointer();
83  // Alloca always returns a pointer in alloca address space, which may
84  // be different from the type defined by the language. For example,
85  // in C++ the auto variables are in the default address space. Therefore
86  // cast alloca to the default address space when necessary.
88  auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
89  llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
90  // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
91  // otherwise alloca is inserted at the current insertion point of the
92  // builder.
93  if (!ArraySize)
94  Builder.SetInsertPoint(AllocaInsertPt);
97  Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
98  }
99 
100  return Address(V, Align);
101 }
102 
103 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
104 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
105 /// insertion point of the builder.
107  const Twine &Name,
108  llvm::Value *ArraySize) {
109  if (ArraySize)
110  return Builder.CreateAlloca(Ty, ArraySize, Name);
111  return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
112  ArraySize, Name, AllocaInsertPt);
113 }
114 
115 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
116 /// default alignment of the corresponding LLVM type, which is *not*
117 /// guaranteed to be related in any way to the expected alignment of
118 /// an AST type that might have been lowered to Ty.
120  const Twine &Name) {
121  CharUnits Align =
122  CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
123  return CreateTempAlloca(Ty, Align, Name);
124 }
125 
127  assert(isa<llvm::AllocaInst>(Var.getPointer()));
128  auto *Store = new llvm::StoreInst(Init, Var.getPointer());
129  Store->setAlignment(Var.getAlignment().getQuantity());
130  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
131  Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
132 }
133 
136  return CreateTempAlloca(ConvertType(Ty), Align, Name);
137 }
138 
140  Address *Alloca) {
141  // FIXME: Should we prefer the preferred type alignment here?
142  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
143 }
144 
146  const Twine &Name, Address *Alloca) {
147  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
148  /*ArraySize=*/nullptr, Alloca);
149 }
150 
152  const Twine &Name) {
153  return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
154 }
155 
157  const Twine &Name) {
158  return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
159  Name);
160 }
161 
162 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
163 /// expression and compare the result against zero, returning an Int1Ty value.
165  PGO.setCurrentStmt(E);
166  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
167  llvm::Value *MemPtr = EmitScalarExpr(E);
168  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
169  }
170 
171  QualType BoolTy = getContext().BoolTy;
172  SourceLocation Loc = E->getExprLoc();
173  if (!E->getType()->isAnyComplexType())
174  return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
175 
176  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
177  Loc);
178 }
179 
180 /// EmitIgnoredExpr - Emit code to compute the specified expression,
181 /// ignoring the result.
183  if (E->isRValue())
184  return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
185 
186  // Just emit it as an l-value and drop the result.
187  EmitLValue(E);
188 }
189 
190 /// EmitAnyExpr - Emit code to compute the specified expression which
191 /// can have any type. The result is returned as an RValue struct.
192 /// If this is an aggregate expression, AggSlot indicates where the
193 /// result should be returned.
195  AggValueSlot aggSlot,
196  bool ignoreResult) {
197  switch (getEvaluationKind(E->getType())) {
198  case TEK_Scalar:
199  return RValue::get(EmitScalarExpr(E, ignoreResult));
200  case TEK_Complex:
201  return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
202  case TEK_Aggregate:
203  if (!ignoreResult && aggSlot.isIgnored())
204  aggSlot = CreateAggTemp(E->getType(), "agg-temp");
205  EmitAggExpr(E, aggSlot);
206  return aggSlot.asRValue();
207  }
208  llvm_unreachable("bad evaluation kind");
209 }
210 
211 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
212 /// always be accessible even if no aggregate location is provided.
215 
217  AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
218  return EmitAnyExpr(E, AggSlot);
219 }
220 
221 /// EmitAnyExprToMem - Evaluate an expression into a given memory
222 /// location.
224  Address Location,
225  Qualifiers Quals,
226  bool IsInit) {
227  // FIXME: This function should take an LValue as an argument.
228  switch (getEvaluationKind(E->getType())) {
229  case TEK_Complex:
231  /*isInit*/ false);
232  return;
233 
234  case TEK_Aggregate: {
235  EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
238  AggValueSlot::IsAliased_t(!IsInit),
240  return;
241  }
242 
243  case TEK_Scalar: {
244  RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
245  LValue LV = MakeAddrLValue(Location, E->getType());
246  EmitStoreThroughLValue(RV, LV);
247  return;
248  }
249  }
250  llvm_unreachable("bad evaluation kind");
251 }
252 
253 static void
255  const Expr *E, Address ReferenceTemporary) {
256  // Objective-C++ ARC:
257  // If we are binding a reference to a temporary that has ownership, we
258  // need to perform retain/release operations on the temporary.
259  //
260  // FIXME: This should be looking at E, not M.
261  if (auto Lifetime = M->getType().getObjCLifetime()) {
262  switch (Lifetime) {
265  // Carry on to normal cleanup handling.
266  break;
267 
269  // Nothing to do; cleaned up by an autorelease pool.
270  return;
271 
274  switch (StorageDuration Duration = M->getStorageDuration()) {
275  case SD_Static:
276  // Note: we intentionally do not register a cleanup to release
277  // the object on program termination.
278  return;
279 
280  case SD_Thread:
281  // FIXME: We should probably register a cleanup in this case.
282  return;
283 
284  case SD_Automatic:
285  case SD_FullExpression:
288  if (Lifetime == Qualifiers::OCL_Strong) {
289  const ValueDecl *VD = M->getExtendingDecl();
290  bool Precise =
291  VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
292  CleanupKind = CGF.getARCCleanupKind();
293  Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
295  } else {
296  // __weak objects always get EH cleanups; otherwise, exceptions
297  // could cause really nasty crashes instead of mere leaks.
298  CleanupKind = NormalAndEHCleanup;
300  }
301  if (Duration == SD_FullExpression)
302  CGF.pushDestroy(CleanupKind, ReferenceTemporary,
303  M->getType(), *Destroy,
304  CleanupKind & EHCleanup);
305  else
306  CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
307  M->getType(),
308  *Destroy, CleanupKind & EHCleanup);
309  return;
310 
311  case SD_Dynamic:
312  llvm_unreachable("temporary cannot have dynamic storage duration");
313  }
314  llvm_unreachable("unknown storage duration");
315  }
316  }
317 
318  CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
319  if (const RecordType *RT =
321  // Get the destructor for the reference temporary.
322  auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
323  if (!ClassDecl->hasTrivialDestructor())
324  ReferenceTemporaryDtor = ClassDecl->getDestructor();
325  }
326 
327  if (!ReferenceTemporaryDtor)
328  return;
329 
330  // Call the destructor for the temporary.
331  switch (M->getStorageDuration()) {
332  case SD_Static:
333  case SD_Thread: {
334  llvm::Constant *CleanupFn;
335  llvm::Constant *CleanupArg;
336  if (E->getType()->isArrayType()) {
337  CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
338  ReferenceTemporary, E->getType(),
340  dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
341  CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
342  } else {
343  CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
345  CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
346  }
348  CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
349  break;
350  }
351 
352  case SD_FullExpression:
353  CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
355  CGF.getLangOpts().Exceptions);
356  break;
357 
358  case SD_Automatic:
360  ReferenceTemporary, E->getType(),
362  CGF.getLangOpts().Exceptions);
363  break;
364 
365  case SD_Dynamic:
366  llvm_unreachable("temporary cannot have dynamic storage duration");
367  }
368 }
369 
371  const MaterializeTemporaryExpr *M,
372  const Expr *Inner,
373  Address *Alloca = nullptr) {
374  auto &TCG = CGF.getTargetHooks();
375  switch (M->getStorageDuration()) {
376  case SD_FullExpression:
377  case SD_Automatic: {
378  // If we have a constant temporary array or record try to promote it into a
379  // constant global under the same rules a normal constant would've been
380  // promoted. This is easier on the optimizer and generally emits fewer
381  // instructions.
382  QualType Ty = Inner->getType();
383  if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
384  (Ty->isArrayType() || Ty->isRecordType()) &&
385  CGF.CGM.isTypeConstant(Ty, true))
386  if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
387  if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
388  auto AS = AddrSpace.getValue();
389  auto *GV = new llvm::GlobalVariable(
390  CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
391  llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
392  llvm::GlobalValue::NotThreadLocal,
394  CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
395  GV->setAlignment(alignment.getQuantity());
396  llvm::Constant *C = GV;
397  if (AS != LangAS::Default)
398  C = TCG.performAddrSpaceCast(
399  CGF.CGM, GV, AS, LangAS::Default,
400  GV->getValueType()->getPointerTo(
402  // FIXME: Should we put the new global into a COMDAT?
403  return Address(C, alignment);
404  }
405  }
406  return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
407  }
408  case SD_Thread:
409  case SD_Static:
410  return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
411 
412  case SD_Dynamic:
413  llvm_unreachable("temporary can't have dynamic storage duration");
414  }
415  llvm_unreachable("unknown storage duration");
416 }
417 
420  const Expr *E = M->GetTemporaryExpr();
421 
422  // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
423  // as that will cause the lifetime adjustment to be lost for ARC
424  auto ownership = M->getType().getObjCLifetime();
425  if (ownership != Qualifiers::OCL_None &&
426  ownership != Qualifiers::OCL_ExplicitNone) {
427  Address Object = createReferenceTemporary(*this, M, E);
428  if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
429  Object = Address(llvm::ConstantExpr::getBitCast(Var,
431  ->getPointerTo(Object.getAddressSpace())),
432  Object.getAlignment());
433 
434  // createReferenceTemporary will promote the temporary to a global with a
435  // constant initializer if it can. It can only do this to a value of
436  // ARC-manageable type if the value is global and therefore "immune" to
437  // ref-counting operations. Therefore we have no need to emit either a
438  // dynamic initialization or a cleanup and we can just return the address
439  // of the temporary.
440  if (Var->hasInitializer())
441  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
442 
443  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
444  }
445  LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
447 
448  switch (getEvaluationKind(E->getType())) {
449  default: llvm_unreachable("expected scalar or aggregate expression");
450  case TEK_Scalar:
451  EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
452  break;
453  case TEK_Aggregate: {
455  E->getType().getQualifiers(),
460  break;
461  }
462  }
463 
464  pushTemporaryCleanup(*this, M, E, Object);
465  return RefTempDst;
466  }
467 
470  E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
471 
472  for (const auto &Ignored : CommaLHSs)
473  EmitIgnoredExpr(Ignored);
474 
475  if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
476  if (opaque->getType()->isRecordType()) {
477  assert(Adjustments.empty());
478  return EmitOpaqueValueLValue(opaque);
479  }
480  }
481 
482  // Create and initialize the reference temporary.
483  Address Alloca = Address::invalid();
484  Address Object = createReferenceTemporary(*this, M, E, &Alloca);
485  if (auto *Var = dyn_cast<llvm::GlobalVariable>(
486  Object.getPointer()->stripPointerCasts())) {
487  Object = Address(llvm::ConstantExpr::getBitCast(
488  cast<llvm::Constant>(Object.getPointer()),
489  ConvertTypeForMem(E->getType())->getPointerTo()),
490  Object.getAlignment());
491  // If the temporary is a global and has a constant initializer or is a
492  // constant temporary that we promoted to a global, we may have already
493  // initialized it.
494  if (!Var->hasInitializer()) {
495  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
496  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
497  }
498  } else {
499  switch (M->getStorageDuration()) {
500  case SD_Automatic:
501  case SD_FullExpression:
502  if (auto *Size = EmitLifetimeStart(
503  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
504  Alloca.getPointer())) {
505  if (M->getStorageDuration() == SD_Automatic)
506  pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
507  Alloca, Size);
508  else
509  pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
510  Size);
511  }
512  break;
513  default:
514  break;
515  }
516  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
517  }
518  pushTemporaryCleanup(*this, M, E, Object);
519 
520  // Perform derived-to-base casts and/or field accesses, to get from the
521  // temporary object we created (and, potentially, for which we extended
522  // the lifetime) to the subobject we're binding the reference to.
523  for (unsigned I = Adjustments.size(); I != 0; --I) {
524  SubobjectAdjustment &Adjustment = Adjustments[I-1];
525  switch (Adjustment.Kind) {
527  Object =
529  Adjustment.DerivedToBase.BasePath->path_begin(),
530  Adjustment.DerivedToBase.BasePath->path_end(),
531  /*NullCheckValue=*/ false, E->getExprLoc());
532  break;
533 
536  LV = EmitLValueForField(LV, Adjustment.Field);
537  assert(LV.isSimple() &&
538  "materialized temporary field is not a simple lvalue");
539  Object = LV.getAddress();
540  break;
541  }
542 
544  llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
545  Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
546  Adjustment.Ptr.MPT);
547  break;
548  }
549  }
550  }
551 
552  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
553 }
554 
555 RValue
557  // Emit the expression as an lvalue.
558  LValue LV = EmitLValue(E);
559  assert(LV.isSimple());
560  llvm::Value *Value = LV.getPointer();
561 
562  if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
563  // C++11 [dcl.ref]p5 (as amended by core issue 453):
564  // If a glvalue to which a reference is directly bound designates neither
565  // an existing object or function of an appropriate type nor a region of
566  // storage of suitable size and alignment to contain an object of the
567  // reference's type, the behavior is undefined.
568  QualType Ty = E->getType();
570  }
571 
572  return RValue::get(Value);
573 }
574 
575 
576 /// getAccessedFieldNo - Given an encoded value and a result number, return the
577 /// input field number being accessed.
579  const llvm::Constant *Elts) {
580  return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
581  ->getZExtValue();
582 }
583 
584 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
586  llvm::Value *High) {
587  llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
588  llvm::Value *K47 = Builder.getInt64(47);
589  llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
590  llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
591  llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
592  llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
593  return Builder.CreateMul(B1, KMul);
594 }
595 
597  return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
599 }
600 
602  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
603  return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
604  (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
605  TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
607 }
608 
610  return SanOpts.has(SanitizerKind::Null) |
611  SanOpts.has(SanitizerKind::Alignment) |
612  SanOpts.has(SanitizerKind::ObjectSize) |
613  SanOpts.has(SanitizerKind::Vptr);
614 }
615 
617  llvm::Value *Ptr, QualType Ty,
618  CharUnits Alignment,
619  SanitizerSet SkippedChecks) {
621  return;
622 
623  // Don't check pointers outside the default address space. The null check
624  // isn't correct, the object-size check isn't supported by LLVM, and we can't
625  // communicate the addresses to the runtime handler for the vptr check.
626  if (Ptr->getType()->getPointerAddressSpace())
627  return;
628 
629  // Don't check pointers to volatile data. The behavior here is implementation-
630  // defined.
631  if (Ty.isVolatileQualified())
632  return;
633 
634  SanitizerScope SanScope(this);
635 
637  llvm::BasicBlock *Done = nullptr;
638 
639  // Quickly determine whether we have a pointer to an alloca. It's possible
640  // to skip null checks, and some alignment checks, for these pointers. This
641  // can reduce compile-time significantly.
642  auto PtrToAlloca =
643  dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
644 
645  llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
646  llvm::Value *IsNonNull = nullptr;
647  bool IsGuaranteedNonNull =
648  SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
649  bool AllowNullPointers = isNullPointerAllowed(TCK);
650  if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
651  !IsGuaranteedNonNull) {
652  // The glvalue must not be an empty glvalue.
653  IsNonNull = Builder.CreateIsNotNull(Ptr);
654 
655  // The IR builder can constant-fold the null check if the pointer points to
656  // a constant.
657  IsGuaranteedNonNull = IsNonNull == True;
658 
659  // Skip the null check if the pointer is known to be non-null.
660  if (!IsGuaranteedNonNull) {
661  if (AllowNullPointers) {
662  // When performing pointer casts, it's OK if the value is null.
663  // Skip the remaining checks in that case.
664  Done = createBasicBlock("null");
665  llvm::BasicBlock *Rest = createBasicBlock("not.null");
666  Builder.CreateCondBr(IsNonNull, Rest, Done);
667  EmitBlock(Rest);
668  } else {
669  Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
670  }
671  }
672  }
673 
674  if (SanOpts.has(SanitizerKind::ObjectSize) &&
675  !SkippedChecks.has(SanitizerKind::ObjectSize) &&
676  !Ty->isIncompleteType()) {
677  uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
678 
679  // The glvalue must refer to a large enough storage region.
680  // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
681  // to check this.
682  // FIXME: Get object address space
683  llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
684  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
685  llvm::Value *Min = Builder.getFalse();
686  llvm::Value *NullIsUnknown = Builder.getFalse();
687  llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
688  llvm::Value *LargeEnough = Builder.CreateICmpUGE(
689  Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown}),
690  llvm::ConstantInt::get(IntPtrTy, Size));
691  Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
692  }
693 
694  uint64_t AlignVal = 0;
695  llvm::Value *PtrAsInt = nullptr;
696 
697  if (SanOpts.has(SanitizerKind::Alignment) &&
698  !SkippedChecks.has(SanitizerKind::Alignment)) {
699  AlignVal = Alignment.getQuantity();
700  if (!Ty->isIncompleteType() && !AlignVal)
701  AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
702 
703  // The glvalue must be suitably aligned.
704  if (AlignVal > 1 &&
705  (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
706  PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
707  llvm::Value *Align = Builder.CreateAnd(
708  PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
709  llvm::Value *Aligned =
710  Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
711  if (Aligned != True)
712  Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
713  }
714  }
715 
716  if (Checks.size() > 0) {
717  // Make sure we're not losing information. Alignment needs to be a power of
718  // 2
719  assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
720  llvm::Constant *StaticData[] = {
722  llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
723  llvm::ConstantInt::get(Int8Ty, TCK)};
724  EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
725  PtrAsInt ? PtrAsInt : Ptr);
726  }
727 
728  // If possible, check that the vptr indicates that there is a subobject of
729  // type Ty at offset zero within this object.
730  //
731  // C++11 [basic.life]p5,6:
732  // [For storage which does not refer to an object within its lifetime]
733  // The program has undefined behavior if:
734  // -- the [pointer or glvalue] is used to access a non-static data member
735  // or call a non-static member function
736  if (SanOpts.has(SanitizerKind::Vptr) &&
737  !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
738  // Ensure that the pointer is non-null before loading it. If there is no
739  // compile-time guarantee, reuse the run-time null check or emit a new one.
740  if (!IsGuaranteedNonNull) {
741  if (!IsNonNull)
742  IsNonNull = Builder.CreateIsNotNull(Ptr);
743  if (!Done)
744  Done = createBasicBlock("vptr.null");
745  llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
746  Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
747  EmitBlock(VptrNotNull);
748  }
749 
750  // Compute a hash of the mangled name of the type.
751  //
752  // FIXME: This is not guaranteed to be deterministic! Move to a
753  // fingerprinting mechanism once LLVM provides one. For the time
754  // being the implementation happens to be deterministic.
755  SmallString<64> MangledName;
756  llvm::raw_svector_ostream Out(MangledName);
758  Out);
759 
760  // Blacklist based on the mangled type.
762  SanitizerKind::Vptr, Out.str())) {
763  llvm::hash_code TypeHash = hash_value(Out.str());
764 
765  // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
766  llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
767  llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
768  Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
769  llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
770  llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
771 
772  llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
773  Hash = Builder.CreateTrunc(Hash, IntPtrTy);
774 
775  // Look the hash up in our cache.
776  const int CacheSize = 128;
777  llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
779  "__ubsan_vptr_type_cache");
780  llvm::Value *Slot = Builder.CreateAnd(Hash,
781  llvm::ConstantInt::get(IntPtrTy,
782  CacheSize-1));
783  llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
784  llvm::Value *CacheVal =
785  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
786  getPointerAlign());
787 
788  // If the hash isn't in the cache, call a runtime handler to perform the
789  // hard work of checking whether the vptr is for an object of the right
790  // type. This will either fill in the cache and return, or produce a
791  // diagnostic.
792  llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
793  llvm::Constant *StaticData[] = {
797  llvm::ConstantInt::get(Int8Ty, TCK)
798  };
799  llvm::Value *DynamicData[] = { Ptr, Hash };
800  EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
801  SanitizerHandler::DynamicTypeCacheMiss, StaticData,
802  DynamicData);
803  }
804  }
805 
806  if (Done) {
807  Builder.CreateBr(Done);
808  EmitBlock(Done);
809  }
810 }
811 
812 /// Determine whether this expression refers to a flexible array member in a
813 /// struct. We disable array bounds checks for such members.
814 static bool isFlexibleArrayMemberExpr(const Expr *E) {
815  // For compatibility with existing code, we treat arrays of length 0 or
816  // 1 as flexible array members.
817  const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
818  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
819  if (CAT->getSize().ugt(1))
820  return false;
821  } else if (!isa<IncompleteArrayType>(AT))
822  return false;
823 
824  E = E->IgnoreParens();
825 
826  // A flexible array member must be the last member in the class.
827  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
828  // FIXME: If the base type of the member expr is not FD->getParent(),
829  // this should not be treated as a flexible array member access.
830  if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
832  DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
833  return ++FI == FD->getParent()->field_end();
834  }
835  } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
836  return IRE->getDecl()->getNextIvar() == nullptr;
837  }
838 
839  return false;
840 }
841 
843  QualType EltTy) {
844  ASTContext &C = getContext();
845  uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
846  if (!EltSize)
847  return nullptr;
848 
849  auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
850  if (!ArrayDeclRef)
851  return nullptr;
852 
853  auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
854  if (!ParamDecl)
855  return nullptr;
856 
857  auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
858  if (!POSAttr)
859  return nullptr;
860 
861  // Don't load the size if it's a lower bound.
862  int POSType = POSAttr->getType();
863  if (POSType != 0 && POSType != 1)
864  return nullptr;
865 
866  // Find the implicit size parameter.
867  auto PassedSizeIt = SizeArguments.find(ParamDecl);
868  if (PassedSizeIt == SizeArguments.end())
869  return nullptr;
870 
871  const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
872  assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
873  Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
874  llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
875  C.getSizeType(), E->getExprLoc());
876  llvm::Value *SizeOfElement =
877  llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
878  return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
879 }
880 
881 /// If Base is known to point to the start of an array, return the length of
882 /// that array. Return 0 if the length cannot be determined.
884  CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
885  // For the vector indexing extension, the bound is the number of elements.
886  if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
887  IndexedType = Base->getType();
888  return CGF.Builder.getInt32(VT->getNumElements());
889  }
890 
891  Base = Base->IgnoreParens();
892 
893  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
894  if (CE->getCastKind() == CK_ArrayToPointerDecay &&
895  !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
896  IndexedType = CE->getSubExpr()->getType();
897  const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
898  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
899  return CGF.Builder.getInt(CAT->getSize());
900  else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
901  return CGF.getVLASize(VAT).NumElts;
902  // Ignore pass_object_size here. It's not applicable on decayed pointers.
903  }
904  }
905 
906  QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
907  if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
908  IndexedType = Base->getType();
909  return POS;
910  }
911 
912  return nullptr;
913 }
914 
916  llvm::Value *Index, QualType IndexType,
917  bool Accessed) {
918  assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
919  "should not be called unless adding bounds checks");
920  SanitizerScope SanScope(this);
921 
922  QualType IndexedType;
923  llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
924  if (!Bound)
925  return;
926 
927  bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
928  llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
929  llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
930 
931  llvm::Constant *StaticData[] = {
933  EmitCheckTypeDescriptor(IndexedType),
934  EmitCheckTypeDescriptor(IndexType)
935  };
936  llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
937  : Builder.CreateICmpULE(IndexVal, BoundVal);
938  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
939  SanitizerHandler::OutOfBounds, StaticData, Index);
940 }
941 
942 
945  bool isInc, bool isPre) {
946  ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
947 
948  llvm::Value *NextVal;
949  if (isa<llvm::IntegerType>(InVal.first->getType())) {
950  uint64_t AmountVal = isInc ? 1 : -1;
951  NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
952 
953  // Add the inc/dec to the real part.
954  NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
955  } else {
956  QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
957  llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
958  if (!isInc)
959  FVal.changeSign();
960  NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
961 
962  // Add the inc/dec to the real part.
963  NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
964  }
965 
966  ComplexPairTy IncVal(NextVal, InVal.second);
967 
968  // Store the updated result through the lvalue.
969  EmitStoreOfComplex(IncVal, LV, /*init*/ false);
970 
971  // If this is a postinc, return the value read from memory, otherwise use the
972  // updated value.
973  return isPre ? IncVal : InVal;
974 }
975 
977  CodeGenFunction *CGF) {
978  // Bind VLAs in the cast type.
979  if (CGF && E->getType()->isVariablyModifiedType())
981 
982  if (CGDebugInfo *DI = getModuleDebugInfo())
983  DI->EmitExplicitCastType(E->getType());
984 }
985 
986 //===----------------------------------------------------------------------===//
987 // LValue Expression Emission
988 //===----------------------------------------------------------------------===//
989 
990 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
991 /// derive a more accurate bound on the alignment of the pointer.
993  LValueBaseInfo *BaseInfo,
994  TBAAAccessInfo *TBAAInfo) {
995  // We allow this with ObjC object pointers because of fragile ABIs.
996  assert(E->getType()->isPointerType() ||
998  E = E->IgnoreParens();
999 
1000  // Casts:
1001  if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1002  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1003  CGM.EmitExplicitCastExprType(ECE, this);
1004 
1005  switch (CE->getCastKind()) {
1006  // Non-converting casts (but not C's implicit conversion from void*).
1007  case CK_BitCast:
1008  case CK_NoOp:
1009  case CK_AddressSpaceConversion:
1010  if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1011  if (PtrTy->getPointeeType()->isVoidType())
1012  break;
1013 
1014  LValueBaseInfo InnerBaseInfo;
1015  TBAAAccessInfo InnerTBAAInfo;
1016  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1017  &InnerBaseInfo,
1018  &InnerTBAAInfo);
1019  if (BaseInfo) *BaseInfo = InnerBaseInfo;
1020  if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1021 
1022  if (isa<ExplicitCastExpr>(CE)) {
1023  LValueBaseInfo TargetTypeBaseInfo;
1024  TBAAAccessInfo TargetTypeTBAAInfo;
1025  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1026  &TargetTypeBaseInfo,
1027  &TargetTypeTBAAInfo);
1028  if (TBAAInfo)
1029  *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1030  TargetTypeTBAAInfo);
1031  // If the source l-value is opaque, honor the alignment of the
1032  // casted-to type.
1033  if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1034  if (BaseInfo)
1035  BaseInfo->mergeForCast(TargetTypeBaseInfo);
1036  Addr = Address(Addr.getPointer(), Align);
1037  }
1038  }
1039 
1040  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1041  CE->getCastKind() == CK_BitCast) {
1042  if (auto PT = E->getType()->getAs<PointerType>())
1043  EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1044  /*MayBeNull=*/true,
1046  CE->getLocStart());
1047  }
1048  return CE->getCastKind() != CK_AddressSpaceConversion
1049  ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1051  ConvertType(E->getType()));
1052  }
1053  break;
1054 
1055  // Array-to-pointer decay.
1056  case CK_ArrayToPointerDecay:
1057  return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1058 
1059  // Derived-to-base conversions.
1060  case CK_UncheckedDerivedToBase:
1061  case CK_DerivedToBase: {
1062  // TODO: Support accesses to members of base classes in TBAA. For now, we
1063  // conservatively pretend that the complete object is of the base class
1064  // type.
1065  if (TBAAInfo)
1066  *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1067  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1068  auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1069  return GetAddressOfBaseClass(Addr, Derived,
1070  CE->path_begin(), CE->path_end(),
1072  CE->getExprLoc());
1073  }
1074 
1075  // TODO: Is there any reason to treat base-to-derived conversions
1076  // specially?
1077  default:
1078  break;
1079  }
1080  }
1081 
1082  // Unary &.
1083  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1084  if (UO->getOpcode() == UO_AddrOf) {
1085  LValue LV = EmitLValue(UO->getSubExpr());
1086  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1087  if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1088  return LV.getAddress();
1089  }
1090  }
1091 
1092  // TODO: conditional operators, comma.
1093 
1094  // Otherwise, use the alignment of the type.
1095  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1096  TBAAInfo);
1097  return Address(EmitScalarExpr(E), Align);
1098 }
1099 
1101  if (Ty->isVoidType())
1102  return RValue::get(nullptr);
1103 
1104  switch (getEvaluationKind(Ty)) {
1105  case TEK_Complex: {
1106  llvm::Type *EltTy =
1108  llvm::Value *U = llvm::UndefValue::get(EltTy);
1109  return RValue::getComplex(std::make_pair(U, U));
1110  }
1111 
1112  // If this is a use of an undefined aggregate type, the aggregate must have an
1113  // identifiable address. Just because the contents of the value are undefined
1114  // doesn't mean that the address can't be taken and compared.
1115  case TEK_Aggregate: {
1116  Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1117  return RValue::getAggregate(DestPtr);
1118  }
1119 
1120  case TEK_Scalar:
1121  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1122  }
1123  llvm_unreachable("bad evaluation kind");
1124 }
1125 
1127  const char *Name) {
1128  ErrorUnsupported(E, Name);
1129  return GetUndefRValue(E->getType());
1130 }
1131 
1133  const char *Name) {
1134  ErrorUnsupported(E, Name);
1135  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1136  return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1137  E->getType());
1138 }
1139 
1141  const Expr *Base = Obj;
1142  while (!isa<CXXThisExpr>(Base)) {
1143  // The result of a dynamic_cast can be null.
1144  if (isa<CXXDynamicCastExpr>(Base))
1145  return false;
1146 
1147  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1148  Base = CE->getSubExpr();
1149  } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1150  Base = PE->getSubExpr();
1151  } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1152  if (UO->getOpcode() == UO_Extension)
1153  Base = UO->getSubExpr();
1154  else
1155  return false;
1156  } else {
1157  return false;
1158  }
1159  }
1160  return true;
1161 }
1162 
1164  LValue LV;
1165  if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1166  LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1167  else
1168  LV = EmitLValue(E);
1169  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1170  SanitizerSet SkippedChecks;
1171  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1172  bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1173  if (IsBaseCXXThis)
1174  SkippedChecks.set(SanitizerKind::Alignment, true);
1175  if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1176  SkippedChecks.set(SanitizerKind::Null, true);
1177  }
1178  EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1179  E->getType(), LV.getAlignment(), SkippedChecks);
1180  }
1181  return LV;
1182 }
1183 
1184 /// EmitLValue - Emit code to compute a designator that specifies the location
1185 /// of the expression.
1186 ///
1187 /// This can return one of two things: a simple address or a bitfield reference.
1188 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1189 /// an LLVM pointer type.
1190 ///
1191 /// If this returns a bitfield reference, nothing about the pointee type of the
1192 /// LLVM value is known: For example, it may not be a pointer to an integer.
1193 ///
1194 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1195 /// this method guarantees that the returned pointer type will point to an LLVM
1196 /// type of the same size of the lvalue's type. If the lvalue has a variable
1197 /// length type, this is not possible.
1198 ///
1200  ApplyDebugLocation DL(*this, E);
1201  switch (E->getStmtClass()) {
1202  default: return EmitUnsupportedLValue(E, "l-value expression");
1203 
1204  case Expr::ObjCPropertyRefExprClass:
1205  llvm_unreachable("cannot emit a property reference directly");
1206 
1207  case Expr::ObjCSelectorExprClass:
1208  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1209  case Expr::ObjCIsaExprClass:
1210  return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1211  case Expr::BinaryOperatorClass:
1212  return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1213  case Expr::CompoundAssignOperatorClass: {
1214  QualType Ty = E->getType();
1215  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1216  Ty = AT->getValueType();
1217  if (!Ty->isAnyComplexType())
1218  return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1219  return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1220  }
1221  case Expr::CallExprClass:
1222  case Expr::CXXMemberCallExprClass:
1223  case Expr::CXXOperatorCallExprClass:
1224  case Expr::UserDefinedLiteralClass:
1225  return EmitCallExprLValue(cast<CallExpr>(E));
1226  case Expr::VAArgExprClass:
1227  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1228  case Expr::DeclRefExprClass:
1229  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1230  case Expr::ParenExprClass:
1231  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1232  case Expr::GenericSelectionExprClass:
1233  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1234  case Expr::PredefinedExprClass:
1235  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1236  case Expr::StringLiteralClass:
1237  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1238  case Expr::ObjCEncodeExprClass:
1239  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1240  case Expr::PseudoObjectExprClass:
1241  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1242  case Expr::InitListExprClass:
1243  return EmitInitListLValue(cast<InitListExpr>(E));
1244  case Expr::CXXTemporaryObjectExprClass:
1245  case Expr::CXXConstructExprClass:
1246  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1247  case Expr::CXXBindTemporaryExprClass:
1248  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1249  case Expr::CXXUuidofExprClass:
1250  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1251  case Expr::LambdaExprClass:
1252  return EmitLambdaLValue(cast<LambdaExpr>(E));
1253 
1254  case Expr::ExprWithCleanupsClass: {
1255  const auto *cleanups = cast<ExprWithCleanups>(E);
1256  enterFullExpression(cleanups);
1257  RunCleanupsScope Scope(*this);
1258  LValue LV = EmitLValue(cleanups->getSubExpr());
1259  if (LV.isSimple()) {
1260  // Defend against branches out of gnu statement expressions surrounded by
1261  // cleanups.
1262  llvm::Value *V = LV.getPointer();
1263  Scope.ForceCleanup({&V});
1264  return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1265  getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1266  }
1267  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1268  // bitfield lvalue or some other non-simple lvalue?
1269  return LV;
1270  }
1271 
1272  case Expr::CXXDefaultArgExprClass:
1273  return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1274  case Expr::CXXDefaultInitExprClass: {
1276  return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1277  }
1278  case Expr::CXXTypeidExprClass:
1279  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1280 
1281  case Expr::ObjCMessageExprClass:
1282  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1283  case Expr::ObjCIvarRefExprClass:
1284  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1285  case Expr::StmtExprClass:
1286  return EmitStmtExprLValue(cast<StmtExpr>(E));
1287  case Expr::UnaryOperatorClass:
1288  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1289  case Expr::ArraySubscriptExprClass:
1290  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1291  case Expr::OMPArraySectionExprClass:
1292  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1293  case Expr::ExtVectorElementExprClass:
1294  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1295  case Expr::MemberExprClass:
1296  return EmitMemberExpr(cast<MemberExpr>(E));
1297  case Expr::CompoundLiteralExprClass:
1298  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1299  case Expr::ConditionalOperatorClass:
1300  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1301  case Expr::BinaryConditionalOperatorClass:
1302  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1303  case Expr::ChooseExprClass:
1304  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1305  case Expr::OpaqueValueExprClass:
1306  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1307  case Expr::SubstNonTypeTemplateParmExprClass:
1308  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1309  case Expr::ImplicitCastExprClass:
1310  case Expr::CStyleCastExprClass:
1311  case Expr::CXXFunctionalCastExprClass:
1312  case Expr::CXXStaticCastExprClass:
1313  case Expr::CXXDynamicCastExprClass:
1314  case Expr::CXXReinterpretCastExprClass:
1315  case Expr::CXXConstCastExprClass:
1316  case Expr::ObjCBridgedCastExprClass:
1317  return EmitCastLValue(cast<CastExpr>(E));
1318 
1319  case Expr::MaterializeTemporaryExprClass:
1320  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1321 
1322  case Expr::CoawaitExprClass:
1323  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1324  case Expr::CoyieldExprClass:
1325  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1326  }
1327 }
1328 
1329 /// Given an object of the given canonical type, can we safely copy a
1330 /// value out of it based on its initializer?
1332  assert(type.isCanonical());
1333  assert(!type->isReferenceType());
1334 
1335  // Must be const-qualified but non-volatile.
1336  Qualifiers qs = type.getLocalQualifiers();
1337  if (!qs.hasConst() || qs.hasVolatile()) return false;
1338 
1339  // Otherwise, all object types satisfy this except C++ classes with
1340  // mutable subobjects or non-trivial copy/destroy behavior.
1341  if (const auto *RT = dyn_cast<RecordType>(type))
1342  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1343  if (RD->hasMutableFields() || !RD->isTrivial())
1344  return false;
1345 
1346  return true;
1347 }
1348 
1349 /// Can we constant-emit a load of a reference to a variable of the
1350 /// given type? This is different from predicates like
1351 /// Decl::isUsableInConstantExpressions because we do want it to apply
1352 /// in situations that don't necessarily satisfy the language's rules
1353 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1354 /// to do this with const float variables even if those variables
1355 /// aren't marked 'constexpr'.
1361 };
1363  type = type.getCanonicalType();
1364  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1365  if (isConstantEmittableObjectType(ref->getPointeeType()))
1366  return CEK_AsValueOrReference;
1367  return CEK_AsReferenceOnly;
1368  }
1370  return CEK_AsValueOnly;
1371  return CEK_None;
1372 }
1373 
1374 /// Try to emit a reference to the given value without producing it as
1375 /// an l-value. This is actually more than an optimization: we can't
1376 /// produce an l-value for variables that we never actually captured
1377 /// in a block or lambda, which means const int variables or constexpr
1378 /// literals or similar.
1381  ValueDecl *value = refExpr->getDecl();
1382 
1383  // The value needs to be an enum constant or a constant variable.
1385  if (isa<ParmVarDecl>(value)) {
1386  CEK = CEK_None;
1387  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1388  CEK = checkVarTypeForConstantEmission(var->getType());
1389  } else if (isa<EnumConstantDecl>(value)) {
1390  CEK = CEK_AsValueOnly;
1391  } else {
1392  CEK = CEK_None;
1393  }
1394  if (CEK == CEK_None) return ConstantEmission();
1395 
1396  Expr::EvalResult result;
1397  bool resultIsReference;
1398  QualType resultType;
1399 
1400  // It's best to evaluate all the way as an r-value if that's permitted.
1401  if (CEK != CEK_AsReferenceOnly &&
1402  refExpr->EvaluateAsRValue(result, getContext())) {
1403  resultIsReference = false;
1404  resultType = refExpr->getType();
1405 
1406  // Otherwise, try to evaluate as an l-value.
1407  } else if (CEK != CEK_AsValueOnly &&
1408  refExpr->EvaluateAsLValue(result, getContext())) {
1409  resultIsReference = true;
1410  resultType = value->getType();
1411 
1412  // Failure.
1413  } else {
1414  return ConstantEmission();
1415  }
1416 
1417  // In any case, if the initializer has side-effects, abandon ship.
1418  if (result.HasSideEffects)
1419  return ConstantEmission();
1420 
1421  // Emit as a constant.
1422  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1423  result.Val, resultType);
1424 
1425  // Make sure we emit a debug reference to the global variable.
1426  // This should probably fire even for
1427  if (isa<VarDecl>(value)) {
1428  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1429  EmitDeclRefExprDbgValue(refExpr, result.Val);
1430  } else {
1431  assert(isa<EnumConstantDecl>(value));
1432  EmitDeclRefExprDbgValue(refExpr, result.Val);
1433  }
1434 
1435  // If we emitted a reference constant, we need to dereference that.
1436  if (resultIsReference)
1438 
1439  return ConstantEmission::forValue(C);
1440 }
1441 
1443  const MemberExpr *ME) {
1444  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1445  // Try to emit static variable member expressions as DREs.
1446  return DeclRefExpr::Create(
1448  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1449  ME->getType(), ME->getValueKind());
1450  }
1451  return nullptr;
1452 }
1453 
1456  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1457  return tryEmitAsConstant(DRE);
1458  return ConstantEmission();
1459 }
1460 
1462  SourceLocation Loc) {
1463  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1464  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1465  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1466 }
1467 
1469  if (Ty->isBooleanType())
1470  return true;
1471 
1472  if (const EnumType *ET = Ty->getAs<EnumType>())
1473  return ET->getDecl()->getIntegerType()->isBooleanType();
1474 
1475  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1476  return hasBooleanRepresentation(AT->getValueType());
1477 
1478  return false;
1479 }
1480 
1482  llvm::APInt &Min, llvm::APInt &End,
1483  bool StrictEnums, bool IsBool) {
1484  const EnumType *ET = Ty->getAs<EnumType>();
1485  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1486  ET && !ET->getDecl()->isFixed();
1487  if (!IsBool && !IsRegularCPlusPlusEnum)
1488  return false;
1489 
1490  if (IsBool) {
1491  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1492  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1493  } else {
1494  const EnumDecl *ED = ET->getDecl();
1495  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1496  unsigned Bitwidth = LTy->getScalarSizeInBits();
1497  unsigned NumNegativeBits = ED->getNumNegativeBits();
1498  unsigned NumPositiveBits = ED->getNumPositiveBits();
1499 
1500  if (NumNegativeBits) {
1501  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1502  assert(NumBits <= Bitwidth);
1503  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1504  Min = -End;
1505  } else {
1506  assert(NumPositiveBits <= Bitwidth);
1507  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1508  Min = llvm::APInt(Bitwidth, 0);
1509  }
1510  }
1511  return true;
1512 }
1513 
1514 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1515  llvm::APInt Min, End;
1516  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1518  return nullptr;
1519 
1520  llvm::MDBuilder MDHelper(getLLVMContext());
1521  return MDHelper.createRange(Min, End);
1522 }
1523 
1525  SourceLocation Loc) {
1526  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1527  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1528  if (!HasBoolCheck && !HasEnumCheck)
1529  return false;
1530 
1531  bool IsBool = hasBooleanRepresentation(Ty) ||
1532  NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1533  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1534  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1535  if (!NeedsBoolCheck && !NeedsEnumCheck)
1536  return false;
1537 
1538  // Single-bit booleans don't need to be checked. Special-case this to avoid
1539  // a bit width mismatch when handling bitfield values. This is handled by
1540  // EmitFromMemory for the non-bitfield case.
1541  if (IsBool &&
1542  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1543  return false;
1544 
1545  llvm::APInt Min, End;
1546  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1547  return true;
1548 
1549  auto &Ctx = getLLVMContext();
1550  SanitizerScope SanScope(this);
1551  llvm::Value *Check;
1552  --End;
1553  if (!Min) {
1554  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1555  } else {
1556  llvm::Value *Upper =
1557  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1558  llvm::Value *Lower =
1559  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1560  Check = Builder.CreateAnd(Upper, Lower);
1561  }
1562  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1565  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1566  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1567  StaticArgs, EmitCheckValue(Value));
1568  return true;
1569 }
1570 
1572  QualType Ty,
1573  SourceLocation Loc,
1574  LValueBaseInfo BaseInfo,
1575  TBAAAccessInfo TBAAInfo,
1576  bool isNontemporal) {
1577  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1578  // For better performance, handle vector loads differently.
1579  if (Ty->isVectorType()) {
1580  const llvm::Type *EltTy = Addr.getElementType();
1581 
1582  const auto *VTy = cast<llvm::VectorType>(EltTy);
1583 
1584  // Handle vectors of size 3 like size 4 for better performance.
1585  if (VTy->getNumElements() == 3) {
1586 
1587  // Bitcast to vec4 type.
1588  llvm::VectorType *vec4Ty =
1589  llvm::VectorType::get(VTy->getElementType(), 4);
1590  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1591  // Now load value.
1592  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1593 
1594  // Shuffle vector to get vec3.
1595  V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1596  {0, 1, 2}, "extractVec");
1597  return EmitFromMemory(V, Ty);
1598  }
1599  }
1600  }
1601 
1602  // Atomic operations have to be done on integral types.
1603  LValue AtomicLValue =
1604  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1605  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1606  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1607  }
1608 
1609  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1610  if (isNontemporal) {
1611  llvm::MDNode *Node = llvm::MDNode::get(
1612  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1613  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1614  }
1615 
1616  CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1617 
1618  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1619  // In order to prevent the optimizer from throwing away the check, don't
1620  // attach range metadata to the load.
1621  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1622  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1623  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1624 
1625  return EmitFromMemory(Load, Ty);
1626 }
1627 
1629  // Bool has a different representation in memory than in registers.
1630  if (hasBooleanRepresentation(Ty)) {
1631  // This should really always be an i1, but sometimes it's already
1632  // an i8, and it's awkward to track those cases down.
1633  if (Value->getType()->isIntegerTy(1))
1634  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1635  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1636  "wrong value rep of bool");
1637  }
1638 
1639  return Value;
1640 }
1641 
1643  // Bool has a different representation in memory than in registers.
1644  if (hasBooleanRepresentation(Ty)) {
1645  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1646  "wrong value rep of bool");
1647  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1648  }
1649 
1650  return Value;
1651 }
1652 
1654  bool Volatile, QualType Ty,
1655  LValueBaseInfo BaseInfo,
1656  TBAAAccessInfo TBAAInfo,
1657  bool isInit, bool isNontemporal) {
1658  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1659  // Handle vectors differently to get better performance.
1660  if (Ty->isVectorType()) {
1661  llvm::Type *SrcTy = Value->getType();
1662  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1663  // Handle vec3 special.
1664  if (VecTy && VecTy->getNumElements() == 3) {
1665  // Our source is a vec3, do a shuffle vector to make it a vec4.
1666  llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1667  Builder.getInt32(2),
1668  llvm::UndefValue::get(Builder.getInt32Ty())};
1669  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1670  Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1671  MaskV, "extractVec");
1672  SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1673  }
1674  if (Addr.getElementType() != SrcTy) {
1675  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1676  }
1677  }
1678  }
1679 
1680  Value = EmitToMemory(Value, Ty);
1681 
1682  LValue AtomicLValue =
1683  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1684  if (Ty->isAtomicType() ||
1685  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1686  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1687  return;
1688  }
1689 
1690  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1691  if (isNontemporal) {
1692  llvm::MDNode *Node =
1693  llvm::MDNode::get(Store->getContext(),
1694  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1695  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1696  }
1697 
1698  CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1699 }
1700 
1702  bool isInit) {
1703  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1704  lvalue.getType(), lvalue.getBaseInfo(),
1705  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1706 }
1707 
1708 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1709 /// method emits the address of the lvalue, then loads the result as an rvalue,
1710 /// returning the rvalue.
1712  if (LV.isObjCWeak()) {
1713  // load of a __weak object.
1714  Address AddrWeakObj = LV.getAddress();
1716  AddrWeakObj));
1717  }
1719  // In MRC mode, we do a load+autorelease.
1720  if (!getLangOpts().ObjCAutoRefCount) {
1721  return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1722  }
1723 
1724  // In ARC mode, we load retained and then consume the value.
1726  Object = EmitObjCConsumeObject(LV.getType(), Object);
1727  return RValue::get(Object);
1728  }
1729 
1730  if (LV.isSimple()) {
1731  assert(!LV.getType()->isFunctionType());
1732 
1733  // Everything needs a load.
1734  return RValue::get(EmitLoadOfScalar(LV, Loc));
1735  }
1736 
1737  if (LV.isVectorElt()) {
1738  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1739  LV.isVolatileQualified());
1740  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1741  "vecext"));
1742  }
1743 
1744  // If this is a reference to a subset of the elements of a vector, either
1745  // shuffle the input or extract/insert them as appropriate.
1746  if (LV.isExtVectorElt())
1748 
1749  // Global Register variables always invoke intrinsics
1750  if (LV.isGlobalReg())
1751  return EmitLoadOfGlobalRegLValue(LV);
1752 
1753  assert(LV.isBitField() && "Unknown LValue type!");
1754  return EmitLoadOfBitfieldLValue(LV, Loc);
1755 }
1756 
1758  SourceLocation Loc) {
1759  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1760 
1761  // Get the output type.
1762  llvm::Type *ResLTy = ConvertType(LV.getType());
1763 
1764  Address Ptr = LV.getBitFieldAddress();
1765  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1766 
1767  if (Info.IsSigned) {
1768  assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1769  unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1770  if (HighBits)
1771  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1772  if (Info.Offset + HighBits)
1773  Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1774  } else {
1775  if (Info.Offset)
1776  Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1777  if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1778  Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1779  Info.Size),
1780  "bf.clear");
1781  }
1782  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1783  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1784  return RValue::get(Val);
1785 }
1786 
1787 // If this is a reference to a subset of the elements of a vector, create an
1788 // appropriate shufflevector.
1791  LV.isVolatileQualified());
1792 
1793  const llvm::Constant *Elts = LV.getExtVectorElts();
1794 
1795  // If the result of the expression is a non-vector type, we must be extracting
1796  // a single element. Just codegen as an extractelement.
1797  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1798  if (!ExprVT) {
1799  unsigned InIdx = getAccessedFieldNo(0, Elts);
1800  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1801  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1802  }
1803 
1804  // Always use shuffle vector to try to retain the original program structure
1805  unsigned NumResultElts = ExprVT->getNumElements();
1806 
1808  for (unsigned i = 0; i != NumResultElts; ++i)
1809  Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1810 
1811  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1812  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1813  MaskV);
1814  return RValue::get(Vec);
1815 }
1816 
1817 /// Generates lvalue for partial ext_vector access.
1819  Address VectorAddress = LV.getExtVectorAddress();
1820  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1821  QualType EQT = ExprVT->getElementType();
1822  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1823 
1824  Address CastToPointerElement =
1825  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1826  "conv.ptr.element");
1827 
1828  const llvm::Constant *Elts = LV.getExtVectorElts();
1829  unsigned ix = getAccessedFieldNo(0, Elts);
1830 
1831  Address VectorBasePtrPlusIx =
1832  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1833  getContext().getTypeSizeInChars(EQT),
1834  "vector.elt");
1835 
1836  return VectorBasePtrPlusIx;
1837 }
1838 
1839 /// Load of global gamed gegisters are always calls to intrinsics.
1841  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1842  "Bad type for register variable");
1843  llvm::MDNode *RegName = cast<llvm::MDNode>(
1844  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1845 
1846  // We accept integer and pointer types only
1847  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1848  llvm::Type *Ty = OrigTy;
1849  if (OrigTy->isPointerTy())
1850  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1851  llvm::Type *Types[] = { Ty };
1852 
1853  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1854  llvm::Value *Call = Builder.CreateCall(
1855  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1856  if (OrigTy->isPointerTy())
1857  Call = Builder.CreateIntToPtr(Call, OrigTy);
1858  return RValue::get(Call);
1859 }
1860 
1861 
1862 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1863 /// lvalue, where both are guaranteed to the have the same type, and that type
1864 /// is 'Ty'.
1866  bool isInit) {
1867  if (!Dst.isSimple()) {
1868  if (Dst.isVectorElt()) {
1869  // Read/modify/write the vector, inserting the new element.
1871  Dst.isVolatileQualified());
1872  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1873  Dst.getVectorIdx(), "vecins");
1875  Dst.isVolatileQualified());
1876  return;
1877  }
1878 
1879  // If this is an update of extended vector elements, insert them as
1880  // appropriate.
1881  if (Dst.isExtVectorElt())
1883 
1884  if (Dst.isGlobalReg())
1885  return EmitStoreThroughGlobalRegLValue(Src, Dst);
1886 
1887  assert(Dst.isBitField() && "Unknown LValue type");
1888  return EmitStoreThroughBitfieldLValue(Src, Dst);
1889  }
1890 
1891  // There's special magic for assigning into an ARC-qualified l-value.
1892  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1893  switch (Lifetime) {
1894  case Qualifiers::OCL_None:
1895  llvm_unreachable("present but none");
1896 
1898  // nothing special
1899  break;
1900 
1902  if (isInit) {
1903  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1904  break;
1905  }
1906  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1907  return;
1908 
1909  case Qualifiers::OCL_Weak:
1910  if (isInit)
1911  // Initialize and then skip the primitive store.
1912  EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1913  else
1914  EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1915  return;
1916 
1919  Src.getScalarVal()));
1920  // fall into the normal path
1921  break;
1922  }
1923  }
1924 
1925  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1926  // load of a __weak object.
1927  Address LvalueDst = Dst.getAddress();
1928  llvm::Value *src = Src.getScalarVal();
1929  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1930  return;
1931  }
1932 
1933  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1934  // load of a __strong object.
1935  Address LvalueDst = Dst.getAddress();
1936  llvm::Value *src = Src.getScalarVal();
1937  if (Dst.isObjCIvar()) {
1938  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1939  llvm::Type *ResultType = IntPtrTy;
1941  llvm::Value *RHS = dst.getPointer();
1942  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1943  llvm::Value *LHS =
1944  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1945  "sub.ptr.lhs.cast");
1946  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1947  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1948  BytesBetween);
1949  } else if (Dst.isGlobalObjCRef()) {
1950  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1951  Dst.isThreadLocalRef());
1952  }
1953  else
1954  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1955  return;
1956  }
1957 
1958  assert(Src.isScalar() && "Can't emit an agg store with this method");
1959  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1960 }
1961 
1963  llvm::Value **Result) {
1964  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1965  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1966  Address Ptr = Dst.getBitFieldAddress();
1967 
1968  // Get the source value, truncated to the width of the bit-field.
1969  llvm::Value *SrcVal = Src.getScalarVal();
1970 
1971  // Cast the source to the storage type and shift it into place.
1972  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1973  /*IsSigned=*/false);
1974  llvm::Value *MaskedVal = SrcVal;
1975 
1976  // See if there are other bits in the bitfield's storage we'll need to load
1977  // and mask together with source before storing.
1978  if (Info.StorageSize != Info.Size) {
1979  assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1980  llvm::Value *Val =
1981  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1982 
1983  // Mask the source value as needed.
1984  if (!hasBooleanRepresentation(Dst.getType()))
1985  SrcVal = Builder.CreateAnd(SrcVal,
1986  llvm::APInt::getLowBitsSet(Info.StorageSize,
1987  Info.Size),
1988  "bf.value");
1989  MaskedVal = SrcVal;
1990  if (Info.Offset)
1991  SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1992 
1993  // Mask out the original value.
1994  Val = Builder.CreateAnd(Val,
1995  ~llvm::APInt::getBitsSet(Info.StorageSize,
1996  Info.Offset,
1997  Info.Offset + Info.Size),
1998  "bf.clear");
1999 
2000  // Or together the unchanged values and the source value.
2001  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2002  } else {
2003  assert(Info.Offset == 0);
2004  }
2005 
2006  // Write the new value back out.
2007  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2008 
2009  // Return the new value of the bit-field, if requested.
2010  if (Result) {
2011  llvm::Value *ResultVal = MaskedVal;
2012 
2013  // Sign extend the value if needed.
2014  if (Info.IsSigned) {
2015  assert(Info.Size <= Info.StorageSize);
2016  unsigned HighBits = Info.StorageSize - Info.Size;
2017  if (HighBits) {
2018  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2019  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2020  }
2021  }
2022 
2023  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2024  "bf.result.cast");
2025  *Result = EmitFromMemory(ResultVal, Dst.getType());
2026  }
2027 }
2028 
2030  LValue Dst) {
2031  // This access turns into a read/modify/write of the vector. Load the input
2032  // value now.
2034  Dst.isVolatileQualified());
2035  const llvm::Constant *Elts = Dst.getExtVectorElts();
2036 
2037  llvm::Value *SrcVal = Src.getScalarVal();
2038 
2039  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2040  unsigned NumSrcElts = VTy->getNumElements();
2041  unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2042  if (NumDstElts == NumSrcElts) {
2043  // Use shuffle vector is the src and destination are the same number of
2044  // elements and restore the vector mask since it is on the side it will be
2045  // stored.
2046  SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2047  for (unsigned i = 0; i != NumSrcElts; ++i)
2048  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2049 
2050  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2051  Vec = Builder.CreateShuffleVector(SrcVal,
2052  llvm::UndefValue::get(Vec->getType()),
2053  MaskV);
2054  } else if (NumDstElts > NumSrcElts) {
2055  // Extended the source vector to the same length and then shuffle it
2056  // into the destination.
2057  // FIXME: since we're shuffling with undef, can we just use the indices
2058  // into that? This could be simpler.
2060  for (unsigned i = 0; i != NumSrcElts; ++i)
2061  ExtMask.push_back(Builder.getInt32(i));
2062  ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2063  llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2064  llvm::Value *ExtSrcVal =
2065  Builder.CreateShuffleVector(SrcVal,
2066  llvm::UndefValue::get(SrcVal->getType()),
2067  ExtMaskV);
2068  // build identity
2070  for (unsigned i = 0; i != NumDstElts; ++i)
2071  Mask.push_back(Builder.getInt32(i));
2072 
2073  // When the vector size is odd and .odd or .hi is used, the last element
2074  // of the Elts constant array will be one past the size of the vector.
2075  // Ignore the last element here, if it is greater than the mask size.
2076  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2077  NumSrcElts--;
2078 
2079  // modify when what gets shuffled in
2080  for (unsigned i = 0; i != NumSrcElts; ++i)
2081  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2082  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2083  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2084  } else {
2085  // We should never shorten the vector
2086  llvm_unreachable("unexpected shorten vector length");
2087  }
2088  } else {
2089  // If the Src is a scalar (not a vector) it must be updating one element.
2090  unsigned InIdx = getAccessedFieldNo(0, Elts);
2091  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2092  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2093  }
2094 
2096  Dst.isVolatileQualified());
2097 }
2098 
2099 /// Store of global named registers are always calls to intrinsics.
2101  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2102  "Bad type for register variable");
2103  llvm::MDNode *RegName = cast<llvm::MDNode>(
2104  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2105  assert(RegName && "Register LValue is not metadata");
2106 
2107  // We accept integer and pointer types only
2108  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2109  llvm::Type *Ty = OrigTy;
2110  if (OrigTy->isPointerTy())
2111  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2112  llvm::Type *Types[] = { Ty };
2113 
2114  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2115  llvm::Value *Value = Src.getScalarVal();
2116  if (OrigTy->isPointerTy())
2117  Value = Builder.CreatePtrToInt(Value, Ty);
2118  Builder.CreateCall(
2119  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2120 }
2121 
2122 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2123 // generating write-barries API. It is currently a global, ivar,
2124 // or neither.
2125 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2126  LValue &LV,
2127  bool IsMemberAccess=false) {
2128  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2129  return;
2130 
2131  if (isa<ObjCIvarRefExpr>(E)) {
2132  QualType ExpTy = E->getType();
2133  if (IsMemberAccess && ExpTy->isPointerType()) {
2134  // If ivar is a structure pointer, assigning to field of
2135  // this struct follows gcc's behavior and makes it a non-ivar
2136  // writer-barrier conservatively.
2137  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2138  if (ExpTy->isRecordType()) {
2139  LV.setObjCIvar(false);
2140  return;
2141  }
2142  }
2143  LV.setObjCIvar(true);
2144  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2145  LV.setBaseIvarExp(Exp->getBase());
2146  LV.setObjCArray(E->getType()->isArrayType());
2147  return;
2148  }
2149 
2150  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2151  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2152  if (VD->hasGlobalStorage()) {
2153  LV.setGlobalObjCRef(true);
2154  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2155  }
2156  }
2157  LV.setObjCArray(E->getType()->isArrayType());
2158  return;
2159  }
2160 
2161  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2162  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2163  return;
2164  }
2165 
2166  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2167  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2168  if (LV.isObjCIvar()) {
2169  // If cast is to a structure pointer, follow gcc's behavior and make it
2170  // a non-ivar write-barrier.
2171  QualType ExpTy = E->getType();
2172  if (ExpTy->isPointerType())
2173  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2174  if (ExpTy->isRecordType())
2175  LV.setObjCIvar(false);
2176  }
2177  return;
2178  }
2179 
2180  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2181  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2182  return;
2183  }
2184 
2185  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2186  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2187  return;
2188  }
2189 
2190  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2191  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2192  return;
2193  }
2194 
2195  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2196  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2197  return;
2198  }
2199 
2200  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2201  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2202  if (LV.isObjCIvar() && !LV.isObjCArray())
2203  // Using array syntax to assigning to what an ivar points to is not
2204  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2205  LV.setObjCIvar(false);
2206  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2207  // Using array syntax to assigning to what global points to is not
2208  // same as assigning to the global itself. {id *G;} G[i] = 0;
2209  LV.setGlobalObjCRef(false);
2210  return;
2211  }
2212 
2213  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2214  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2215  // We don't know if member is an 'ivar', but this flag is looked at
2216  // only in the context of LV.isObjCIvar().
2217  LV.setObjCArray(E->getType()->isArrayType());
2218  return;
2219  }
2220 }
2221 
2222 static llvm::Value *
2224  llvm::Value *V, llvm::Type *IRType,
2225  StringRef Name = StringRef()) {
2226  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2227  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2228 }
2229 
2231  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2232  llvm::Type *RealVarTy, SourceLocation Loc) {
2233  Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2234  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2235  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2236 }
2237 
2239  const VarDecl *VD, QualType T) {
2240  for (const auto *D : VD->redecls()) {
2241  if (!VD->hasAttrs())
2242  continue;
2243  if (const auto *Attr = D->getAttr<OMPDeclareTargetDeclAttr>())
2244  if (Attr->getMapType() == OMPDeclareTargetDeclAttr::MT_Link) {
2245  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2246  Address Addr =
2247  CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
2248  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2249  }
2250  }
2251  return Address::invalid();
2252 }
2253 
2254 Address
2256  LValueBaseInfo *PointeeBaseInfo,
2257  TBAAAccessInfo *PointeeTBAAInfo) {
2258  llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2259  RefLVal.isVolatile());
2260  CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2261 
2263  PointeeBaseInfo, PointeeTBAAInfo,
2264  /* forPointeeType= */ true);
2265  return Address(Load, Align);
2266 }
2267 
2269  LValueBaseInfo PointeeBaseInfo;
2270  TBAAAccessInfo PointeeTBAAInfo;
2271  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2272  &PointeeTBAAInfo);
2273  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2274  PointeeBaseInfo, PointeeTBAAInfo);
2275 }
2276 
2278  const PointerType *PtrTy,
2279  LValueBaseInfo *BaseInfo,
2280  TBAAAccessInfo *TBAAInfo) {
2281  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2282  return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2283  BaseInfo, TBAAInfo,
2284  /*forPointeeType=*/true));
2285 }
2286 
2288  const PointerType *PtrTy) {
2289  LValueBaseInfo BaseInfo;
2290  TBAAAccessInfo TBAAInfo;
2291  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2292  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2293 }
2294 
2296  const Expr *E, const VarDecl *VD) {
2297  QualType T = E->getType();
2298 
2299  // If it's thread_local, emit a call to its wrapper function instead.
2300  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2302  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2303  // Check if the variable is marked as declare target with link clause in
2304  // device codegen.
2305  if (CGF.getLangOpts().OpenMPIsDevice) {
2306  Address Addr = emitDeclTargetLinkVarDeclLValue(CGF, VD, T);
2307  if (Addr.isValid())
2308  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2309  }
2310 
2311  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2312  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2313  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2314  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2315  Address Addr(V, Alignment);
2316  // Emit reference to the private copy of the variable if it is an OpenMP
2317  // threadprivate variable.
2318  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2319  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2320  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2321  E->getExprLoc());
2322  }
2323  LValue LV = VD->getType()->isReferenceType() ?
2324  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2326  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2327  setObjCGCLValueClass(CGF.getContext(), E, LV);
2328  return LV;
2329 }
2330 
2332  const FunctionDecl *FD) {
2333  if (FD->hasAttr<WeakRefAttr>()) {
2334  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2335  return aliasee.getPointer();
2336  }
2337 
2338  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2339  if (!FD->hasPrototype()) {
2340  if (const FunctionProtoType *Proto =
2341  FD->getType()->getAs<FunctionProtoType>()) {
2342  // Ugly case: for a K&R-style definition, the type of the definition
2343  // isn't the same as the type of a use. Correct for this with a
2344  // bitcast.
2345  QualType NoProtoType =
2346  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2347  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2348  V = llvm::ConstantExpr::getBitCast(V,
2349  CGM.getTypes().ConvertType(NoProtoType));
2350  }
2351  }
2352  return V;
2353 }
2354 
2356  const Expr *E, const FunctionDecl *FD) {
2357  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2358  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2359  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2361 }
2362 
2364  llvm::Value *ThisValue) {
2366  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2367  return CGF.EmitLValueForField(LV, FD);
2368 }
2369 
2370 /// Named Registers are named metadata pointing to the register name
2371 /// which will be read from/written to as an argument to the intrinsic
2372 /// @llvm.read/write_register.
2373 /// So far, only the name is being passed down, but other options such as
2374 /// register type, allocation type or even optimization options could be
2375 /// passed down via the metadata node.
2377  SmallString<64> Name("llvm.named.register.");
2378  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2379  assert(Asm->getLabel().size() < 64-Name.size() &&
2380  "Register name too big");
2381  Name.append(Asm->getLabel());
2382  llvm::NamedMDNode *M =
2383  CGM.getModule().getOrInsertNamedMetadata(Name);
2384  if (M->getNumOperands() == 0) {
2385  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2386  Asm->getLabel());
2387  llvm::Metadata *Ops[] = {Str};
2388  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2389  }
2390 
2391  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2392 
2393  llvm::Value *Ptr =
2394  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2395  return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2396 }
2397 
2399  const NamedDecl *ND = E->getDecl();
2400  QualType T = E->getType();
2401 
2402  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2403  // Global Named registers access via intrinsics only
2404  if (VD->getStorageClass() == SC_Register &&
2405  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2406  return EmitGlobalNamedRegister(VD, CGM);
2407 
2408  // A DeclRefExpr for a reference initialized by a constant expression can
2409  // appear without being odr-used. Directly emit the constant initializer.
2410  const Expr *Init = VD->getAnyInitializer(VD);
2411  if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2412  VD->isUsableInConstantExpressions(getContext()) &&
2413  VD->checkInitIsICE() &&
2414  // Do not emit if it is private OpenMP variable.
2416  ((CapturedStmtInfo &&
2417  (LocalDeclMap.count(VD->getCanonicalDecl()) ||
2418  CapturedStmtInfo->lookup(VD->getCanonicalDecl()))) ||
2419  LambdaCaptureFields.lookup(VD->getCanonicalDecl()) ||
2420  isa<BlockDecl>(CurCodeDecl)))) {
2421  llvm::Constant *Val =
2423  *VD->evaluateValue(),
2424  VD->getType());
2425  assert(Val && "failed to emit reference constant expression");
2426  // FIXME: Eventually we will want to emit vector element references.
2427 
2428  // Should we be using the alignment of the constant pointer we emitted?
2429  CharUnits Alignment = getNaturalTypeAlignment(E->getType(),
2430  /* BaseInfo= */ nullptr,
2431  /* TBAAInfo= */ nullptr,
2432  /* forPointeeType= */ true);
2433  return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2434  }
2435 
2436  // Check for captured variables.
2438  VD = VD->getCanonicalDecl();
2439  if (auto *FD = LambdaCaptureFields.lookup(VD))
2440  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2441  else if (CapturedStmtInfo) {
2442  auto I = LocalDeclMap.find(VD);
2443  if (I != LocalDeclMap.end()) {
2444  if (VD->getType()->isReferenceType())
2445  return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2447  return MakeAddrLValue(I->second, T);
2448  }
2449  LValue CapLVal =
2452  return MakeAddrLValue(
2453  Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2455  CapLVal.getTBAAInfo());
2456  }
2457 
2458  assert(isa<BlockDecl>(CurCodeDecl));
2459  Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2460  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2461  }
2462  }
2463 
2464  // FIXME: We should be able to assert this for FunctionDecls as well!
2465  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2466  // those with a valid source location.
2467  assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2468  !E->getLocation().isValid()) &&
2469  "Should not use decl without marking it used!");
2470 
2471  if (ND->hasAttr<WeakRefAttr>()) {
2472  const auto *VD = cast<ValueDecl>(ND);
2473  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2474  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2475  }
2476 
2477  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2478  // Check if this is a global variable.
2479  if (VD->hasLinkage() || VD->isStaticDataMember())
2480  return EmitGlobalVarDeclLValue(*this, E, VD);
2481 
2482  Address addr = Address::invalid();
2483 
2484  // The variable should generally be present in the local decl map.
2485  auto iter = LocalDeclMap.find(VD);
2486  if (iter != LocalDeclMap.end()) {
2487  addr = iter->second;
2488 
2489  // Otherwise, it might be static local we haven't emitted yet for
2490  // some reason; most likely, because it's in an outer function.
2491  } else if (VD->isStaticLocal()) {
2493  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2494  getContext().getDeclAlign(VD));
2495 
2496  // No other cases for now.
2497  } else {
2498  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2499  }
2500 
2501 
2502  // Check for OpenMP threadprivate variables.
2503  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2504  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2506  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2507  E->getExprLoc());
2508  }
2509 
2510  // Drill into block byref variables.
2511  bool isBlockByref = VD->hasAttr<BlocksAttr>();
2512  if (isBlockByref) {
2513  addr = emitBlockByrefAddress(addr, VD);
2514  }
2515 
2516  // Drill into reference types.
2517  LValue LV = VD->getType()->isReferenceType() ?
2520 
2521  bool isLocalStorage = VD->hasLocalStorage();
2522 
2523  bool NonGCable = isLocalStorage &&
2524  !VD->getType()->isReferenceType() &&
2525  !isBlockByref;
2526  if (NonGCable) {
2527  LV.getQuals().removeObjCGCAttr();
2528  LV.setNonGC(true);
2529  }
2530 
2531  bool isImpreciseLifetime =
2532  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2533  if (isImpreciseLifetime)
2535  setObjCGCLValueClass(getContext(), E, LV);
2536  return LV;
2537  }
2538 
2539  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2540  return EmitFunctionDeclLValue(*this, E, FD);
2541 
2542  // FIXME: While we're emitting a binding from an enclosing scope, all other
2543  // DeclRefExprs we see should be implicitly treated as if they also refer to
2544  // an enclosing scope.
2545  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2546  return EmitLValue(BD->getBinding());
2547 
2548  llvm_unreachable("Unhandled DeclRefExpr");
2549 }
2550 
2552  // __extension__ doesn't affect lvalue-ness.
2553  if (E->getOpcode() == UO_Extension)
2554  return EmitLValue(E->getSubExpr());
2555 
2557  switch (E->getOpcode()) {
2558  default: llvm_unreachable("Unknown unary operator lvalue!");
2559  case UO_Deref: {
2560  QualType T = E->getSubExpr()->getType()->getPointeeType();
2561  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2562 
2563  LValueBaseInfo BaseInfo;
2564  TBAAAccessInfo TBAAInfo;
2565  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2566  &TBAAInfo);
2567  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2568  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2569 
2570  // We should not generate __weak write barrier on indirect reference
2571  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2572  // But, we continue to generate __strong write barrier on indirect write
2573  // into a pointer to object.
2574  if (getLangOpts().ObjC1 &&
2575  getLangOpts().getGC() != LangOptions::NonGC &&
2576  LV.isObjCWeak())
2577  LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2578  return LV;
2579  }
2580  case UO_Real:
2581  case UO_Imag: {
2582  LValue LV = EmitLValue(E->getSubExpr());
2583  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2584 
2585  // __real is valid on scalars. This is a faster way of testing that.
2586  // __imag can only produce an rvalue on scalars.
2587  if (E->getOpcode() == UO_Real &&
2588  !LV.getAddress().getElementType()->isStructTy()) {
2589  assert(E->getSubExpr()->getType()->isArithmeticType());
2590  return LV;
2591  }
2592 
2593  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2594 
2595  Address Component =
2596  (E->getOpcode() == UO_Real
2599  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2600  CGM.getTBAAInfoForSubobject(LV, T));
2601  ElemLV.getQuals().addQualifiers(LV.getQuals());
2602  return ElemLV;
2603  }
2604  case UO_PreInc:
2605  case UO_PreDec: {
2606  LValue LV = EmitLValue(E->getSubExpr());
2607  bool isInc = E->getOpcode() == UO_PreInc;
2608 
2609  if (E->getType()->isAnyComplexType())
2610  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2611  else
2612  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2613  return LV;
2614  }
2615  }
2616 }
2617 
2621 }
2622 
2626 }
2627 
2629  auto SL = E->getFunctionName();
2630  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2631  StringRef FnName = CurFn->getName();
2632  if (FnName.startswith("\01"))
2633  FnName = FnName.substr(1);
2634  StringRef NameItems[] = {
2636  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2637  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2638  std::string Name = SL->getString();
2639  if (!Name.empty()) {
2640  unsigned Discriminator =
2641  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2642  if (Discriminator)
2643  Name += "_" + Twine(Discriminator + 1).str();
2644  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2645  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2646  } else {
2647  auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2648  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2649  }
2650  }
2651  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2652  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2653 }
2654 
2655 /// Emit a type description suitable for use by a runtime sanitizer library. The
2656 /// format of a type descriptor is
2657 ///
2658 /// \code
2659 /// { i16 TypeKind, i16 TypeInfo }
2660 /// \endcode
2661 ///
2662 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2663 /// integer, 1 for a floating point value, and -1 for anything else.
2665  // Only emit each type's descriptor once.
2666  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2667  return C;
2668 
2669  uint16_t TypeKind = -1;
2670  uint16_t TypeInfo = 0;
2671 
2672  if (T->isIntegerType()) {
2673  TypeKind = 0;
2674  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2675  (T->isSignedIntegerType() ? 1 : 0);
2676  } else if (T->isFloatingType()) {
2677  TypeKind = 1;
2678  TypeInfo = getContext().getTypeSize(T);
2679  }
2680 
2681  // Format the type name as if for a diagnostic, including quotes and
2682  // optionally an 'aka'.
2683  SmallString<32> Buffer;
2685  (intptr_t)T.getAsOpaquePtr(),
2686  StringRef(), StringRef(), None, Buffer,
2687  None);
2688 
2689  llvm::Constant *Components[] = {
2690  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2691  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2692  };
2693  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2694 
2695  auto *GV = new llvm::GlobalVariable(
2696  CGM.getModule(), Descriptor->getType(),
2697  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2698  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2700 
2701  // Remember the descriptor for this type.
2702  CGM.setTypeDescriptorInMap(T, GV);
2703 
2704  return GV;
2705 }
2706 
2708  llvm::Type *TargetTy = IntPtrTy;
2709 
2710  if (V->getType() == TargetTy)
2711  return V;
2712 
2713  // Floating-point types which fit into intptr_t are bitcast to integers
2714  // and then passed directly (after zero-extension, if necessary).
2715  if (V->getType()->isFloatingPointTy()) {
2716  unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2717  if (Bits <= TargetTy->getIntegerBitWidth())
2718  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2719  Bits));
2720  }
2721 
2722  // Integers which fit in intptr_t are zero-extended and passed directly.
2723  if (V->getType()->isIntegerTy() &&
2724  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2725  return Builder.CreateZExt(V, TargetTy);
2726 
2727  // Pointers are passed directly, everything else is passed by address.
2728  if (!V->getType()->isPointerTy()) {
2729  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2730  Builder.CreateStore(V, Ptr);
2731  V = Ptr.getPointer();
2732  }
2733  return Builder.CreatePtrToInt(V, TargetTy);
2734 }
2735 
2736 /// Emit a representation of a SourceLocation for passing to a handler
2737 /// in a sanitizer runtime library. The format for this data is:
2738 /// \code
2739 /// struct SourceLocation {
2740 /// const char *Filename;
2741 /// int32_t Line, Column;
2742 /// };
2743 /// \endcode
2744 /// For an invalid SourceLocation, the Filename pointer is null.
2746  llvm::Constant *Filename;
2747  int Line, Column;
2748 
2750  if (PLoc.isValid()) {
2751  StringRef FilenameString = PLoc.getFilename();
2752 
2753  int PathComponentsToStrip =
2754  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2755  if (PathComponentsToStrip < 0) {
2756  assert(PathComponentsToStrip != INT_MIN);
2757  int PathComponentsToKeep = -PathComponentsToStrip;
2758  auto I = llvm::sys::path::rbegin(FilenameString);
2759  auto E = llvm::sys::path::rend(FilenameString);
2760  while (I != E && --PathComponentsToKeep)
2761  ++I;
2762 
2763  FilenameString = FilenameString.substr(I - E);
2764  } else if (PathComponentsToStrip > 0) {
2765  auto I = llvm::sys::path::begin(FilenameString);
2766  auto E = llvm::sys::path::end(FilenameString);
2767  while (I != E && PathComponentsToStrip--)
2768  ++I;
2769 
2770  if (I != E)
2771  FilenameString =
2772  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2773  else
2774  FilenameString = llvm::sys::path::filename(FilenameString);
2775  }
2776 
2777  auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2779  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2780  Filename = FilenameGV.getPointer();
2781  Line = PLoc.getLine();
2782  Column = PLoc.getColumn();
2783  } else {
2784  Filename = llvm::Constant::getNullValue(Int8PtrTy);
2785  Line = Column = 0;
2786  }
2787 
2788  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2789  Builder.getInt32(Column)};
2790 
2791  return llvm::ConstantStruct::getAnon(Data);
2792 }
2793 
2794 namespace {
2795 /// Specify under what conditions this check can be recovered
2797  /// Always terminate program execution if this check fails.
2798  Unrecoverable,
2799  /// Check supports recovering, runtime has both fatal (noreturn) and
2800  /// non-fatal handlers for this check.
2801  Recoverable,
2802  /// Runtime conditionally aborts, always need to support recovery.
2804 };
2805 }
2806 
2808  assert(llvm::countPopulation(Kind) == 1);
2809  switch (Kind) {
2810  case SanitizerKind::Vptr:
2812  case SanitizerKind::Return:
2813  case SanitizerKind::Unreachable:
2815  default:
2816  return CheckRecoverableKind::Recoverable;
2817  }
2818 }
2819 
2820 namespace {
2821 struct SanitizerHandlerInfo {
2822  char const *const Name;
2823  unsigned Version;
2824 };
2825 }
2826 
2827 const SanitizerHandlerInfo SanitizerHandlers[] = {
2828 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2830 #undef SANITIZER_CHECK
2831 };
2832 
2834  llvm::FunctionType *FnType,
2835  ArrayRef<llvm::Value *> FnArgs,
2836  SanitizerHandler CheckHandler,
2837  CheckRecoverableKind RecoverKind, bool IsFatal,
2838  llvm::BasicBlock *ContBB) {
2839  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2840  bool NeedsAbortSuffix =
2841  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2842  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2843  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2844  const StringRef CheckName = CheckInfo.Name;
2845  std::string FnName = "__ubsan_handle_" + CheckName.str();
2846  if (CheckInfo.Version && !MinimalRuntime)
2847  FnName += "_v" + llvm::utostr(CheckInfo.Version);
2848  if (MinimalRuntime)
2849  FnName += "_minimal";
2850  if (NeedsAbortSuffix)
2851  FnName += "_abort";
2852  bool MayReturn =
2853  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2854 
2855  llvm::AttrBuilder B;
2856  if (!MayReturn) {
2857  B.addAttribute(llvm::Attribute::NoReturn)
2858  .addAttribute(llvm::Attribute::NoUnwind);
2859  }
2860  B.addAttribute(llvm::Attribute::UWTable);
2861 
2863  FnType, FnName,
2864  llvm::AttributeList::get(CGF.getLLVMContext(),
2865  llvm::AttributeList::FunctionIndex, B),
2866  /*Local=*/true);
2867  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2868  if (!MayReturn) {
2869  HandlerCall->setDoesNotReturn();
2870  CGF.Builder.CreateUnreachable();
2871  } else {
2872  CGF.Builder.CreateBr(ContBB);
2873  }
2874 }
2875 
2877  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2878  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2879  ArrayRef<llvm::Value *> DynamicArgs) {
2880  assert(IsSanitizerScope);
2881  assert(Checked.size() > 0);
2882  assert(CheckHandler >= 0 &&
2883  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
2884  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2885 
2886  llvm::Value *FatalCond = nullptr;
2887  llvm::Value *RecoverableCond = nullptr;
2888  llvm::Value *TrapCond = nullptr;
2889  for (int i = 0, n = Checked.size(); i < n; ++i) {
2890  llvm::Value *Check = Checked[i].first;
2891  // -fsanitize-trap= overrides -fsanitize-recover=.
2892  llvm::Value *&Cond =
2893  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2894  ? TrapCond
2895  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2896  ? RecoverableCond
2897  : FatalCond;
2898  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2899  }
2900 
2901  if (TrapCond)
2902  EmitTrapCheck(TrapCond);
2903  if (!FatalCond && !RecoverableCond)
2904  return;
2905 
2906  llvm::Value *JointCond;
2907  if (FatalCond && RecoverableCond)
2908  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2909  else
2910  JointCond = FatalCond ? FatalCond : RecoverableCond;
2911  assert(JointCond);
2912 
2913  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2914  assert(SanOpts.has(Checked[0].second));
2915 #ifndef NDEBUG
2916  for (int i = 1, n = Checked.size(); i < n; ++i) {
2917  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2918  "All recoverable kinds in a single check must be same!");
2919  assert(SanOpts.has(Checked[i].second));
2920  }
2921 #endif
2922 
2923  llvm::BasicBlock *Cont = createBasicBlock("cont");
2924  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2925  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2926  // Give hint that we very much don't expect to execute the handler
2927  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2928  llvm::MDBuilder MDHelper(getLLVMContext());
2929  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2930  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2931  EmitBlock(Handlers);
2932 
2933  // Handler functions take an i8* pointing to the (handler-specific) static
2934  // information block, followed by a sequence of intptr_t arguments
2935  // representing operand values.
2938  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
2939  Args.reserve(DynamicArgs.size() + 1);
2940  ArgTypes.reserve(DynamicArgs.size() + 1);
2941 
2942  // Emit handler arguments and create handler function type.
2943  if (!StaticArgs.empty()) {
2944  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2945  auto *InfoPtr =
2946  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2947  llvm::GlobalVariable::PrivateLinkage, Info);
2948  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2950  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2951  ArgTypes.push_back(Int8PtrTy);
2952  }
2953 
2954  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2955  Args.push_back(EmitCheckValue(DynamicArgs[i]));
2956  ArgTypes.push_back(IntPtrTy);
2957  }
2958  }
2959 
2960  llvm::FunctionType *FnType =
2961  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2962 
2963  if (!FatalCond || !RecoverableCond) {
2964  // Simple case: we need to generate a single handler call, either
2965  // fatal, or non-fatal.
2966  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
2967  (FatalCond != nullptr), Cont);
2968  } else {
2969  // Emit two handler calls: first one for set of unrecoverable checks,
2970  // another one for recoverable.
2971  llvm::BasicBlock *NonFatalHandlerBB =
2972  createBasicBlock("non_fatal." + CheckName);
2973  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2974  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2975  EmitBlock(FatalHandlerBB);
2976  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
2977  NonFatalHandlerBB);
2978  EmitBlock(NonFatalHandlerBB);
2979  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
2980  Cont);
2981  }
2982 
2983  EmitBlock(Cont);
2984 }
2985 
2987  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2988  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2989  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2990 
2991  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2992  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2993 
2994  llvm::MDBuilder MDHelper(getLLVMContext());
2995  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2996  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2997 
2998  EmitBlock(CheckBB);
2999 
3000  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3001 
3002  llvm::CallInst *CheckCall;
3003  llvm::Constant *SlowPathFn;
3004  if (WithDiag) {
3005  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3006  auto *InfoPtr =
3007  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3008  llvm::GlobalVariable::PrivateLinkage, Info);
3009  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3011 
3012  SlowPathFn = CGM.getModule().getOrInsertFunction(
3013  "__cfi_slowpath_diag",
3014  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3015  false));
3016  CheckCall = Builder.CreateCall(
3017  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3018  } else {
3019  SlowPathFn = CGM.getModule().getOrInsertFunction(
3020  "__cfi_slowpath",
3021  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3022  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3023  }
3024 
3025  CGM.setDSOLocal(cast<llvm::GlobalValue>(SlowPathFn->stripPointerCasts()));
3026  CheckCall->setDoesNotThrow();
3027 
3028  EmitBlock(Cont);
3029 }
3030 
3031 // Emit a stub for __cfi_check function so that the linker knows about this
3032 // symbol in LTO mode.
3034  llvm::Module *M = &CGM.getModule();
3035  auto &Ctx = M->getContext();
3036  llvm::Function *F = llvm::Function::Create(
3037  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3038  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3039  CGM.setDSOLocal(F);
3040  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3041  // FIXME: consider emitting an intrinsic call like
3042  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3043  // which can be lowered in CrossDSOCFI pass to the actual contents of
3044  // __cfi_check. This would allow inlining of __cfi_check calls.
3046  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3047  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3048 }
3049 
3050 // This function is basically a switch over the CFI failure kind, which is
3051 // extracted from CFICheckFailData (1st function argument). Each case is either
3052 // llvm.trap or a call to one of the two runtime handlers, based on
3053 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3054 // failure kind) traps, but this should really never happen. CFICheckFailData
3055 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3056 // check kind; in this case __cfi_check_fail traps as well.
3058  SanitizerScope SanScope(this);
3059  FunctionArgList Args;
3064  Args.push_back(&ArgData);
3065  Args.push_back(&ArgAddr);
3066 
3067  const CGFunctionInfo &FI =
3069 
3070  llvm::Function *F = llvm::Function::Create(
3071  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3072  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3073  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3074 
3075  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3076  SourceLocation());
3077 
3078  // This function should not be affected by blacklist. This function does
3079  // not have a source location, but "src:*" would still apply. Revert any
3080  // changes to SanOpts made in StartFunction.
3082 
3083  llvm::Value *Data =
3084  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3085  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3086  llvm::Value *Addr =
3087  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3088  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3089 
3090  // Data == nullptr means the calling module has trap behaviour for this check.
3091  llvm::Value *DataIsNotNullPtr =
3092  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3093  EmitTrapCheck(DataIsNotNullPtr);
3094 
3095  llvm::StructType *SourceLocationTy =
3096  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3097  llvm::StructType *CfiCheckFailDataTy =
3098  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3099 
3100  llvm::Value *V = Builder.CreateConstGEP2_32(
3101  CfiCheckFailDataTy,
3102  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3103  0);
3104  Address CheckKindAddr(V, getIntAlign());
3105  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3106 
3107  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3108  CGM.getLLVMContext(),
3109  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3110  llvm::Value *ValidVtable = Builder.CreateZExt(
3111  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3112  {Addr, AllVtables}),
3113  IntPtrTy);
3114 
3115  const std::pair<int, SanitizerMask> CheckKinds[] = {
3116  {CFITCK_VCall, SanitizerKind::CFIVCall},
3117  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3118  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3119  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3120  {CFITCK_ICall, SanitizerKind::CFIICall}};
3121 
3123  for (auto CheckKindMaskPair : CheckKinds) {
3124  int Kind = CheckKindMaskPair.first;
3125  SanitizerMask Mask = CheckKindMaskPair.second;
3126  llvm::Value *Cond =
3127  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3128  if (CGM.getLangOpts().Sanitize.has(Mask))
3129  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3130  {Data, Addr, ValidVtable});
3131  else
3132  EmitTrapCheck(Cond);
3133  }
3134 
3135  FinishFunction();
3136  // The only reference to this function will be created during LTO link.
3137  // Make sure it survives until then.
3138  CGM.addUsedGlobal(F);
3139 }
3140 
3142  if (SanOpts.has(SanitizerKind::Unreachable)) {
3143  SanitizerScope SanScope(this);
3144  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3145  SanitizerKind::Unreachable),
3146  SanitizerHandler::BuiltinUnreachable,
3147  EmitCheckSourceLocation(Loc), None);
3148  }
3149  Builder.CreateUnreachable();
3150 }
3151 
3153  llvm::BasicBlock *Cont = createBasicBlock("cont");
3154 
3155  // If we're optimizing, collapse all calls to trap down to just one per
3156  // function to save on code size.
3157  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3158  TrapBB = createBasicBlock("trap");
3159  Builder.CreateCondBr(Checked, Cont, TrapBB);
3160  EmitBlock(TrapBB);
3161  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3162  TrapCall->setDoesNotReturn();
3163  TrapCall->setDoesNotThrow();
3164  Builder.CreateUnreachable();
3165  } else {
3166  Builder.CreateCondBr(Checked, Cont, TrapBB);
3167  }
3168 
3169  EmitBlock(Cont);
3170 }
3171 
3173  llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3174 
3175  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3176  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3178  TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3179  }
3180 
3181  return TrapCall;
3182 }
3183 
3185  LValueBaseInfo *BaseInfo,
3186  TBAAAccessInfo *TBAAInfo) {
3187  assert(E->getType()->isArrayType() &&
3188  "Array to pointer decay must have array source type!");
3189 
3190  // Expressions of array type can't be bitfields or vector elements.
3191  LValue LV = EmitLValue(E);
3192  Address Addr = LV.getAddress();
3193 
3194  // If the array type was an incomplete type, we need to make sure
3195  // the decay ends up being the right type.
3196  llvm::Type *NewTy = ConvertType(E->getType());
3197  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3198 
3199  // Note that VLA pointers are always decayed, so we don't need to do
3200  // anything here.
3201  if (!E->getType()->isVariableArrayType()) {
3202  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3203  "Expected pointer to array");
3204  Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
3205  }
3206 
3207  // The result of this decay conversion points to an array element within the
3208  // base lvalue. However, since TBAA currently does not support representing
3209  // accesses to elements of member arrays, we conservatively represent accesses
3210  // to the pointee object as if it had no any base lvalue specified.
3211  // TODO: Support TBAA for member arrays.
3213  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3214  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3215 
3216  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3217 }
3218 
3219 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3220 /// array to pointer, return the array subexpression.
3221 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3222  // If this isn't just an array->pointer decay, bail out.
3223  const auto *CE = dyn_cast<CastExpr>(E);
3224  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3225  return nullptr;
3226 
3227  // If this is a decay from variable width array, bail out.
3228  const Expr *SubExpr = CE->getSubExpr();
3229  if (SubExpr->getType()->isVariableArrayType())
3230  return nullptr;
3231 
3232  return SubExpr;
3233 }
3234 
3236  llvm::Value *ptr,
3237  ArrayRef<llvm::Value*> indices,
3238  bool inbounds,
3239  bool signedIndices,
3240  SourceLocation loc,
3241  const llvm::Twine &name = "arrayidx") {
3242  if (inbounds) {
3243  return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3245  name);
3246  } else {
3247  return CGF.Builder.CreateGEP(ptr, indices, name);
3248  }
3249 }
3250 
3252  llvm::Value *idx,
3253  CharUnits eltSize) {
3254  // If we have a constant index, we can use the exact offset of the
3255  // element we're accessing.
3256  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3257  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3258  return arrayAlign.alignmentAtOffset(offset);
3259 
3260  // Otherwise, use the worst-case alignment for any element.
3261  } else {
3262  return arrayAlign.alignmentOfArrayElement(eltSize);
3263  }
3264 }
3265 
3267  const VariableArrayType *vla) {
3268  QualType eltType;
3269  do {
3270  eltType = vla->getElementType();
3271  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3272  return eltType;
3273 }
3274 
3276  ArrayRef<llvm::Value *> indices,
3277  QualType eltType, bool inbounds,
3278  bool signedIndices, SourceLocation loc,
3279  const llvm::Twine &name = "arrayidx") {
3280  // All the indices except that last must be zero.
3281 #ifndef NDEBUG
3282  for (auto idx : indices.drop_back())
3283  assert(isa<llvm::ConstantInt>(idx) &&
3284  cast<llvm::ConstantInt>(idx)->isZero());
3285 #endif
3286 
3287  // Determine the element size of the statically-sized base. This is
3288  // the thing that the indices are expressed in terms of.
3289  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3290  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3291  }
3292 
3293  // We can use that to compute the best alignment of the element.
3294  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3295  CharUnits eltAlign =
3296  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3297 
3299  CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
3300  return Address(eltPtr, eltAlign);
3301 }
3302 
3304  bool Accessed) {
3305  // The index must always be an integer, which is not an aggregate. Emit it
3306  // in lexical order (this complexity is, sadly, required by C++17).
3307  llvm::Value *IdxPre =
3308  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3309  bool SignedIndices = false;
3310  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3311  auto *Idx = IdxPre;
3312  if (E->getLHS() != E->getIdx()) {
3313  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3314  Idx = EmitScalarExpr(E->getIdx());
3315  }
3316 
3317  QualType IdxTy = E->getIdx()->getType();
3318  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3319  SignedIndices |= IdxSigned;
3320 
3321  if (SanOpts.has(SanitizerKind::ArrayBounds))
3322  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3323 
3324  // Extend or truncate the index type to 32 or 64-bits.
3325  if (Promote && Idx->getType() != IntPtrTy)
3326  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3327 
3328  return Idx;
3329  };
3330  IdxPre = nullptr;
3331 
3332  // If the base is a vector type, then we are forming a vector element lvalue
3333  // with this subscript.
3334  if (E->getBase()->getType()->isVectorType() &&
3335  !isa<ExtVectorElementExpr>(E->getBase())) {
3336  // Emit the vector as an lvalue to get its address.
3337  LValue LHS = EmitLValue(E->getBase());
3338  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3339  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3340  return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3341  LHS.getBaseInfo(), TBAAAccessInfo());
3342  }
3343 
3344  // All the other cases basically behave like simple offsetting.
3345 
3346  // Handle the extvector case we ignored above.
3347  if (isa<ExtVectorElementExpr>(E->getBase())) {
3348  LValue LV = EmitLValue(E->getBase());
3349  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3351 
3352  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3353  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3354  SignedIndices, E->getExprLoc());
3355  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3356  CGM.getTBAAInfoForSubobject(LV, EltType));
3357  }
3358 
3359  LValueBaseInfo EltBaseInfo;
3360  TBAAAccessInfo EltTBAAInfo;
3361  Address Addr = Address::invalid();
3362  if (const VariableArrayType *vla =
3363  getContext().getAsVariableArrayType(E->getType())) {
3364  // The base must be a pointer, which is not an aggregate. Emit
3365  // it. It needs to be emitted first in case it's what captures
3366  // the VLA bounds.
3367  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3368  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3369 
3370  // The element count here is the total number of non-VLA elements.
3371  llvm::Value *numElements = getVLASize(vla).NumElts;
3372 
3373  // Effectively, the multiply by the VLA size is part of the GEP.
3374  // GEP indexes are signed, and scaling an index isn't permitted to
3375  // signed-overflow, so we use the same semantics for our explicit
3376  // multiply. We suppress this if overflow is not undefined behavior.
3377  if (getLangOpts().isSignedOverflowDefined()) {
3378  Idx = Builder.CreateMul(Idx, numElements);
3379  } else {
3380  Idx = Builder.CreateNSWMul(Idx, numElements);
3381  }
3382 
3383  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3385  SignedIndices, E->getExprLoc());
3386 
3387  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3388  // Indexing over an interface, as in "NSString *P; P[4];"
3389 
3390  // Emit the base pointer.
3391  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3392  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3393 
3394  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3395  llvm::Value *InterfaceSizeVal =
3396  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3397 
3398  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3399 
3400  // We don't necessarily build correct LLVM struct types for ObjC
3401  // interfaces, so we can't rely on GEP to do this scaling
3402  // correctly, so we need to cast to i8*. FIXME: is this actually
3403  // true? A lot of other things in the fragile ABI would break...
3404  llvm::Type *OrigBaseTy = Addr.getType();
3405  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3406 
3407  // Do the GEP.
3408  CharUnits EltAlign =
3409  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3410  llvm::Value *EltPtr =
3411  emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3412  SignedIndices, E->getExprLoc());
3413  Addr = Address(EltPtr, EltAlign);
3414 
3415  // Cast back.
3416  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3417  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3418  // If this is A[i] where A is an array, the frontend will have decayed the
3419  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3420  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3421  // "gep x, i" here. Emit one "gep A, 0, i".
3422  assert(Array->getType()->isArrayType() &&
3423  "Array to pointer decay must have array source type!");
3424  LValue ArrayLV;
3425  // For simple multidimensional array indexing, set the 'accessed' flag for
3426  // better bounds-checking of the base expression.
3427  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3428  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3429  else
3430  ArrayLV = EmitLValue(Array);
3431  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3432 
3433  // Propagate the alignment from the array itself to the result.
3434  Addr = emitArraySubscriptGEP(
3435  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3436  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3437  E->getExprLoc());
3438  EltBaseInfo = ArrayLV.getBaseInfo();
3439  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3440  } else {
3441  // The base must be a pointer; emit it with an estimate of its alignment.
3442  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3443  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3444  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3446  SignedIndices, E->getExprLoc());
3447  }
3448 
3449  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3450 
3451  if (getLangOpts().ObjC1 &&
3452  getLangOpts().getGC() != LangOptions::NonGC) {
3454  setObjCGCLValueClass(getContext(), E, LV);
3455  }
3456  return LV;
3457 }
3458 
3460  LValueBaseInfo &BaseInfo,
3461  TBAAAccessInfo &TBAAInfo,
3462  QualType BaseTy, QualType ElTy,
3463  bool IsLowerBound) {
3464  LValue BaseLVal;
3465  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3466  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3467  if (BaseTy->isArrayType()) {
3468  Address Addr = BaseLVal.getAddress();
3469  BaseInfo = BaseLVal.getBaseInfo();
3470 
3471  // If the array type was an incomplete type, we need to make sure
3472  // the decay ends up being the right type.
3473  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3474  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3475 
3476  // Note that VLA pointers are always decayed, so we don't need to do
3477  // anything here.
3478  if (!BaseTy->isVariableArrayType()) {
3479  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3480  "Expected pointer to array");
3481  Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3482  "arraydecay");
3483  }
3484 
3485  return CGF.Builder.CreateElementBitCast(Addr,
3486  CGF.ConvertTypeForMem(ElTy));
3487  }
3488  LValueBaseInfo TypeBaseInfo;
3489  TBAAAccessInfo TypeTBAAInfo;
3490  CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3491  &TypeTBAAInfo);
3492  BaseInfo.mergeForCast(TypeBaseInfo);
3493  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3494  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3495  }
3496  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3497 }
3498 
3500  bool IsLowerBound) {
3502  QualType ResultExprTy;
3503  if (auto *AT = getContext().getAsArrayType(BaseTy))
3504  ResultExprTy = AT->getElementType();
3505  else
3506  ResultExprTy = BaseTy->getPointeeType();
3507  llvm::Value *Idx = nullptr;
3508  if (IsLowerBound || E->getColonLoc().isInvalid()) {
3509  // Requesting lower bound or upper bound, but without provided length and
3510  // without ':' symbol for the default length -> length = 1.
3511  // Idx = LowerBound ?: 0;
3512  if (auto *LowerBound = E->getLowerBound()) {
3513  Idx = Builder.CreateIntCast(
3514  EmitScalarExpr(LowerBound), IntPtrTy,
3515  LowerBound->getType()->hasSignedIntegerRepresentation());
3516  } else
3517  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3518  } else {
3519  // Try to emit length or lower bound as constant. If this is possible, 1
3520  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3521  // IR (LB + Len) - 1.
3522  auto &C = CGM.getContext();
3523  auto *Length = E->getLength();
3524  llvm::APSInt ConstLength;
3525  if (Length) {
3526  // Idx = LowerBound + Length - 1;
3527  if (Length->isIntegerConstantExpr(ConstLength, C)) {
3528  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3529  Length = nullptr;
3530  }
3531  auto *LowerBound = E->getLowerBound();
3532  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3533  if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3534  ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3535  LowerBound = nullptr;
3536  }
3537  if (!Length)
3538  --ConstLength;
3539  else if (!LowerBound)
3540  --ConstLowerBound;
3541 
3542  if (Length || LowerBound) {
3543  auto *LowerBoundVal =
3544  LowerBound
3545  ? Builder.CreateIntCast(
3546  EmitScalarExpr(LowerBound), IntPtrTy,
3547  LowerBound->getType()->hasSignedIntegerRepresentation())
3548  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3549  auto *LengthVal =
3550  Length
3551  ? Builder.CreateIntCast(
3552  EmitScalarExpr(Length), IntPtrTy,
3553  Length->getType()->hasSignedIntegerRepresentation())
3554  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3555  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3556  /*HasNUW=*/false,
3557  !getLangOpts().isSignedOverflowDefined());
3558  if (Length && LowerBound) {
3559  Idx = Builder.CreateSub(
3560  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3561  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3562  }
3563  } else
3564  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3565  } else {
3566  // Idx = ArraySize - 1;
3567  QualType ArrayTy = BaseTy->isPointerType()
3568  ? E->getBase()->IgnoreParenImpCasts()->getType()
3569  : BaseTy;
3570  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3571  Length = VAT->getSizeExpr();
3572  if (Length->isIntegerConstantExpr(ConstLength, C))
3573  Length = nullptr;
3574  } else {
3575  auto *CAT = C.getAsConstantArrayType(ArrayTy);
3576  ConstLength = CAT->getSize();
3577  }
3578  if (Length) {
3579  auto *LengthVal = Builder.CreateIntCast(
3580  EmitScalarExpr(Length), IntPtrTy,
3581  Length->getType()->hasSignedIntegerRepresentation());
3582  Idx = Builder.CreateSub(
3583  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3584  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3585  } else {
3586  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3587  --ConstLength;
3588  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3589  }
3590  }
3591  }
3592  assert(Idx);
3593 
3594  Address EltPtr = Address::invalid();
3595  LValueBaseInfo BaseInfo;
3596  TBAAAccessInfo TBAAInfo;
3597  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3598  // The base must be a pointer, which is not an aggregate. Emit
3599  // it. It needs to be emitted first in case it's what captures
3600  // the VLA bounds.
3601  Address Base =
3602  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3603  BaseTy, VLA->getElementType(), IsLowerBound);
3604  // The element count here is the total number of non-VLA elements.
3605  llvm::Value *NumElements = getVLASize(VLA).NumElts;
3606 
3607  // Effectively, the multiply by the VLA size is part of the GEP.
3608  // GEP indexes are signed, and scaling an index isn't permitted to
3609  // signed-overflow, so we use the same semantics for our explicit
3610  // multiply. We suppress this if overflow is not undefined behavior.
3611  if (getLangOpts().isSignedOverflowDefined())
3612  Idx = Builder.CreateMul(Idx, NumElements);
3613  else
3614  Idx = Builder.CreateNSWMul(Idx, NumElements);
3615  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3617  /*SignedIndices=*/false, E->getExprLoc());
3618  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3619  // If this is A[i] where A is an array, the frontend will have decayed the
3620  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3621  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3622  // "gep x, i" here. Emit one "gep A, 0, i".
3623  assert(Array->getType()->isArrayType() &&
3624  "Array to pointer decay must have array source type!");
3625  LValue ArrayLV;
3626  // For simple multidimensional array indexing, set the 'accessed' flag for
3627  // better bounds-checking of the base expression.
3628  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3629  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3630  else
3631  ArrayLV = EmitLValue(Array);
3632 
3633  // Propagate the alignment from the array itself to the result.
3634  EltPtr = emitArraySubscriptGEP(
3635  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3636  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3637  /*SignedIndices=*/false, E->getExprLoc());
3638  BaseInfo = ArrayLV.getBaseInfo();
3639  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3640  } else {
3641  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3642  TBAAInfo, BaseTy, ResultExprTy,
3643  IsLowerBound);
3644  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3645  !getLangOpts().isSignedOverflowDefined(),
3646  /*SignedIndices=*/false, E->getExprLoc());
3647  }
3648 
3649  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3650 }
3651 
3654  // Emit the base vector as an l-value.
3655  LValue Base;
3656 
3657  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3658  if (E->isArrow()) {
3659  // If it is a pointer to a vector, emit the address and form an lvalue with
3660  // it.
3661  LValueBaseInfo BaseInfo;
3662  TBAAAccessInfo TBAAInfo;
3663  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3664  const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3665  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3666  Base.getQuals().removeObjCGCAttr();
3667  } else if (E->getBase()->isGLValue()) {
3668  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3669  // emit the base as an lvalue.
3670  assert(E->getBase()->getType()->isVectorType());
3671  Base = EmitLValue(E->getBase());
3672  } else {
3673  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3674  assert(E->getBase()->getType()->isVectorType() &&
3675  "Result must be a vector");
3676  llvm::Value *Vec = EmitScalarExpr(E->getBase());
3677 
3678  // Store the vector to memory (because LValue wants an address).
3679  Address VecMem = CreateMemTemp(E->getBase()->getType());
3680  Builder.CreateStore(Vec, VecMem);
3681  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3683  }
3684 
3685  QualType type =
3687 
3688  // Encode the element access list into a vector of unsigned indices.
3689  SmallVector<uint32_t, 4> Indices;
3690  E->getEncodedElementAccess(Indices);
3691 
3692  if (Base.isSimple()) {
3693  llvm::Constant *CV =
3694  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3695  return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3696  Base.getBaseInfo(), TBAAAccessInfo());
3697  }
3698  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3699 
3700  llvm::Constant *BaseElts = Base.getExtVectorElts();
3702 
3703  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3704  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3705  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3707  Base.getBaseInfo(), TBAAAccessInfo());
3708 }
3709 
3711  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3712  EmitIgnoredExpr(E->getBase());
3713  return EmitDeclRefLValue(DRE);
3714  }
3715 
3716  Expr *BaseExpr = E->getBase();
3717  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3718  LValue BaseLV;
3719  if (E->isArrow()) {
3720  LValueBaseInfo BaseInfo;
3721  TBAAAccessInfo TBAAInfo;
3722  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3723  QualType PtrTy = BaseExpr->getType()->getPointeeType();
3724  SanitizerSet SkippedChecks;
3725  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3726  if (IsBaseCXXThis)
3727  SkippedChecks.set(SanitizerKind::Alignment, true);
3728  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3729  SkippedChecks.set(SanitizerKind::Null, true);
3730  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3731  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3732  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3733  } else
3734  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3735 
3736  NamedDecl *ND = E->getMemberDecl();
3737  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3738  LValue LV = EmitLValueForField(BaseLV, Field);
3739  setObjCGCLValueClass(getContext(), E, LV);
3740  return LV;
3741  }
3742 
3743  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3744  return EmitFunctionDeclLValue(*this, E, FD);
3745 
3746  llvm_unreachable("Unhandled member declaration!");
3747 }
3748 
3749 /// Given that we are currently emitting a lambda, emit an l-value for
3750 /// one of its members.
3752  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3753  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3754  QualType LambdaTagType =
3755  getContext().getTagDeclType(Field->getParent());
3756  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3757  return EmitLValueForField(LambdaLV, Field);
3758 }
3759 
3760 /// Drill down to the storage of a field without walking into
3761 /// reference types.
3762 ///
3763 /// The resulting address doesn't necessarily have the right type.
3765  const FieldDecl *field) {
3766  const RecordDecl *rec = field->getParent();
3767 
3768  unsigned idx =
3769  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3770 
3771  CharUnits offset;
3772  // Adjust the alignment down to the given offset.
3773  // As a special case, if the LLVM field index is 0, we know that this
3774  // is zero.
3775  assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3776  .getFieldOffset(field->getFieldIndex()) == 0) &&
3777  "LLVM field at index zero had non-zero offset?");
3778  if (idx != 0) {
3779  auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3780  auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3781  offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3782  }
3783 
3784  return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3785 }
3786 
3787 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3788  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3789  if (!RD)
3790  return false;
3791 
3792  if (RD->isDynamicClass())
3793  return true;
3794 
3795  for (const auto &Base : RD->bases())
3796  if (hasAnyVptr(Base.getType(), Context))
3797  return true;
3798 
3799  for (const FieldDecl *Field : RD->fields())
3800  if (hasAnyVptr(Field->getType(), Context))
3801  return true;
3802 
3803  return false;
3804 }
3805 
3807  const FieldDecl *field) {
3808  LValueBaseInfo BaseInfo = base.getBaseInfo();
3809 
3810  if (field->isBitField()) {
3811  const CGRecordLayout &RL =
3813  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3814  Address Addr = base.getAddress();
3815  unsigned Idx = RL.getLLVMFieldNo(field);
3816  if (Idx != 0)
3817  // For structs, we GEP to the field that the record layout suggests.
3818  Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3819  field->getName());
3820  // Get the access type.
3821  llvm::Type *FieldIntTy =
3822  llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3823  if (Addr.getElementType() != FieldIntTy)
3824  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3825 
3826  QualType fieldType =
3827  field->getType().withCVRQualifiers(base.getVRQualifiers());
3828  // TODO: Support TBAA for bit fields.
3829  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
3830  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
3831  TBAAAccessInfo());
3832  }
3833 
3834  // Fields of may-alias structures are may-alias themselves.
3835  // FIXME: this should get propagated down through anonymous structs
3836  // and unions.
3837  QualType FieldType = field->getType();
3838  const RecordDecl *rec = field->getParent();
3839  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
3840  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
3841  TBAAAccessInfo FieldTBAAInfo;
3842  if (base.getTBAAInfo().isMayAlias() ||
3843  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
3844  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3845  } else if (rec->isUnion()) {
3846  // TODO: Support TBAA for unions.
3847  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3848  } else {
3849  // If no base type been assigned for the base access, then try to generate
3850  // one for this base lvalue.
3851  FieldTBAAInfo = base.getTBAAInfo();
3852  if (!FieldTBAAInfo.BaseType) {
3853  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
3854  assert(!FieldTBAAInfo.Offset &&
3855  "Nonzero offset for an access with no base type!");
3856  }
3857 
3858  // Adjust offset to be relative to the base type.
3859  const ASTRecordLayout &Layout =
3861  unsigned CharWidth = getContext().getCharWidth();
3862  if (FieldTBAAInfo.BaseType)
3863  FieldTBAAInfo.Offset +=
3864  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
3865 
3866  // Update the final access type and size.
3867  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
3868  FieldTBAAInfo.Size =
3869  getContext().getTypeSizeInChars(FieldType).getQuantity();
3870  }
3871 
3872  Address addr = base.getAddress();
3873  if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
3874  if (CGM.getCodeGenOpts().StrictVTablePointers &&
3875  ClassDef->isDynamicClass()) {
3876  // Getting to any field of dynamic object requires stripping dynamic
3877  // information provided by invariant.group. This is because accessing
3878  // fields may leak the real address of dynamic object, which could result
3879  // in miscompilation when leaked pointer would be compared.
3880  auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
3881  addr = Address(stripped, addr.getAlignment());
3882  }
3883  }
3884 
3885  unsigned RecordCVR = base.getVRQualifiers();
3886  if (rec->isUnion()) {
3887  // For unions, there is no pointer adjustment.
3888  assert(!FieldType->isReferenceType() && "union has reference member");
3889  if (CGM.getCodeGenOpts().StrictVTablePointers &&
3890  hasAnyVptr(FieldType, getContext()))
3891  // Because unions can easily skip invariant.barriers, we need to add
3892  // a barrier every time CXXRecord field with vptr is referenced.
3893  addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
3894  addr.getAlignment());
3895  } else {
3896  // For structs, we GEP to the field that the record layout suggests.
3897  addr = emitAddrOfFieldStorage(*this, addr, field);
3898 
3899  // If this is a reference field, load the reference right now.
3900  if (FieldType->isReferenceType()) {
3901  LValue RefLVal = MakeAddrLValue(addr, FieldType, FieldBaseInfo,
3902  FieldTBAAInfo);
3903  if (RecordCVR & Qualifiers::Volatile)
3904  RefLVal.getQuals().setVolatile(true);
3905  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
3906 
3907  // Qualifiers on the struct don't apply to the referencee.
3908  RecordCVR = 0;
3909  FieldType = FieldType->getPointeeType();
3910  }
3911  }
3912 
3913  // Make sure that the address is pointing to the right type. This is critical
3914  // for both unions and structs. A union needs a bitcast, a struct element
3915  // will need a bitcast if the LLVM type laid out doesn't match the desired
3916  // type.
3918  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
3919 
3920  if (field->hasAttr<AnnotateAttr>())
3921  addr = EmitFieldAnnotations(field, addr);
3922 
3923  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
3924  LV.getQuals().addCVRQualifiers(RecordCVR);
3925 
3926  // __weak attribute on a field is ignored.
3927  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3928  LV.getQuals().removeObjCGCAttr();
3929 
3930  return LV;
3931 }
3932 
3933 LValue
3935  const FieldDecl *Field) {
3936  QualType FieldType = Field->getType();
3937 
3938  if (!FieldType->isReferenceType())
3939  return EmitLValueForField(Base, Field);
3940 
3941  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3942 
3943  // Make sure that the address is pointing to the right type.
3944  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3945  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3946 
3947  // TODO: Generate TBAA information that describes this access as a structure
3948  // member access and not just an access to an object of the field's type. This
3949  // should be similar to what we do in EmitLValueForField().
3950  LValueBaseInfo BaseInfo = Base.getBaseInfo();
3951  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
3952  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
3953  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
3954  CGM.getTBAAInfoForSubobject(Base, FieldType));
3955 }
3956 
3958  if (E->isFileScope()) {
3960  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3961  }
3962  if (E->getType()->isVariablyModifiedType())
3963  // make sure to emit the VLA size.
3965 
3966  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3967  const Expr *InitExpr = E->getInitializer();
3968  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
3969 
3970  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3971  /*Init*/ true);
3972 
3973  return Result;
3974 }
3975 
3977  if (!E->isGLValue())
3978  // Initializing an aggregate temporary in C++11: T{...}.
3979  return EmitAggExprToLValue(E);
3980 
3981  // An lvalue initializer list must be initializing a reference.
3982  assert(E->isTransparent() && "non-transparent glvalue init list");
3983  return EmitLValue(E->getInit(0));
3984 }
3985 
3986 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3987 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3988 /// LValue is returned and the current block has been terminated.
3990  const Expr *Operand) {
3991  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3992  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3993  return None;
3994  }
3995 
3996  return CGF.EmitLValue(Operand);
3997 }
3998 
4001  if (!expr->isGLValue()) {
4002  // ?: here should be an aggregate.
4003  assert(hasAggregateEvaluationKind(expr->getType()) &&
4004  "Unexpected conditional operator!");
4005  return EmitAggExprToLValue(expr);
4006  }
4007 
4008  OpaqueValueMapping binding(*this, expr);
4009 
4010  const Expr *condExpr = expr->getCond();
4011  bool CondExprBool;
4012  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4013  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4014  if (!CondExprBool) std::swap(live, dead);
4015 
4016  if (!ContainsLabel(dead)) {
4017  // If the true case is live, we need to track its region.
4018  if (CondExprBool)
4020  return EmitLValue(live);
4021  }
4022  }
4023 
4024  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4025  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4026  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4027 
4028  ConditionalEvaluation eval(*this);
4029  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4030 
4031  // Any temporaries created here are conditional.
4032  EmitBlock(lhsBlock);
4034  eval.begin(*this);
4035  Optional<LValue> lhs =
4036  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4037  eval.end(*this);
4038 
4039  if (lhs && !lhs->isSimple())
4040  return EmitUnsupportedLValue(expr, "conditional operator");
4041 
4042  lhsBlock = Builder.GetInsertBlock();
4043  if (lhs)
4044  Builder.CreateBr(contBlock);
4045 
4046  // Any temporaries created here are conditional.
4047  EmitBlock(rhsBlock);
4048  eval.begin(*this);
4049  Optional<LValue> rhs =
4050  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4051  eval.end(*this);
4052  if (rhs && !rhs->isSimple())
4053  return EmitUnsupportedLValue(expr, "conditional operator");
4054  rhsBlock = Builder.GetInsertBlock();
4055 
4056  EmitBlock(contBlock);
4057 
4058  if (lhs && rhs) {
4059  llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4060  2, "cond-lvalue");
4061  phi->addIncoming(lhs->getPointer(), lhsBlock);
4062  phi->addIncoming(rhs->getPointer(), rhsBlock);
4063  Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4064  AlignmentSource alignSource =
4065  std::max(lhs->getBaseInfo().getAlignmentSource(),
4066  rhs->getBaseInfo().getAlignmentSource());
4068  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4069  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4070  TBAAInfo);
4071  } else {
4072  assert((lhs || rhs) &&
4073  "both operands of glvalue conditional are throw-expressions?");
4074  return lhs ? *lhs : *rhs;
4075  }
4076 }
4077 
4078 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4079 /// type. If the cast is to a reference, we can have the usual lvalue result,
4080 /// otherwise if a cast is needed by the code generator in an lvalue context,
4081 /// then it must mean that we need the address of an aggregate in order to
4082 /// access one of its members. This can happen for all the reasons that casts
4083 /// are permitted with aggregate result, including noop aggregate casts, and
4084 /// cast from scalar to union.
4086  switch (E->getCastKind()) {
4087  case CK_ToVoid:
4088  case CK_BitCast:
4089  case CK_ArrayToPointerDecay:
4090  case CK_FunctionToPointerDecay:
4091  case CK_NullToMemberPointer:
4092  case CK_NullToPointer:
4093  case CK_IntegralToPointer:
4094  case CK_PointerToIntegral:
4095  case CK_PointerToBoolean:
4096  case CK_VectorSplat:
4097  case CK_IntegralCast:
4098  case CK_BooleanToSignedIntegral:
4099  case CK_IntegralToBoolean:
4100  case CK_IntegralToFloating:
4101  case CK_FloatingToIntegral:
4102  case CK_FloatingToBoolean:
4103  case CK_FloatingCast:
4104  case CK_FloatingRealToComplex:
4105  case CK_FloatingComplexToReal:
4106  case CK_FloatingComplexToBoolean:
4107  case CK_FloatingComplexCast:
4108  case CK_FloatingComplexToIntegralComplex:
4109  case CK_IntegralRealToComplex:
4110  case CK_IntegralComplexToReal:
4111  case CK_IntegralComplexToBoolean:
4112  case CK_IntegralComplexCast:
4113  case CK_IntegralComplexToFloatingComplex:
4114  case CK_DerivedToBaseMemberPointer:
4115  case CK_BaseToDerivedMemberPointer:
4116  case CK_MemberPointerToBoolean:
4117  case CK_ReinterpretMemberPointer:
4118  case CK_AnyPointerToBlockPointerCast:
4119  case CK_ARCProduceObject:
4120  case CK_ARCConsumeObject:
4121  case CK_ARCReclaimReturnedObject:
4122  case CK_ARCExtendBlockObject:
4123  case CK_CopyAndAutoreleaseBlockObject:
4124  case CK_AddressSpaceConversion:
4125  case CK_IntToOCLSampler:
4126  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4127 
4128  case CK_Dependent:
4129  llvm_unreachable("dependent cast kind in IR gen!");
4130 
4131  case CK_BuiltinFnToFnPtr:
4132  llvm_unreachable("builtin functions are handled elsewhere");
4133 
4134  // These are never l-values; just use the aggregate emission code.
4135  case CK_NonAtomicToAtomic:
4136  case CK_AtomicToNonAtomic:
4137  return EmitAggExprToLValue(E);
4138 
4139  case CK_Dynamic: {
4140  LValue LV = EmitLValue(E->getSubExpr());
4141  Address V = LV.getAddress();
4142  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4143  return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4144  }
4145 
4146  case CK_ConstructorConversion:
4147  case CK_UserDefinedConversion:
4148  case CK_CPointerToObjCPointerCast:
4149  case CK_BlockPointerToObjCPointerCast:
4150  case CK_NoOp:
4151  case CK_LValueToRValue:
4152  return EmitLValue(E->getSubExpr());
4153 
4154  case CK_UncheckedDerivedToBase:
4155  case CK_DerivedToBase: {
4156  const RecordType *DerivedClassTy =
4157  E->getSubExpr()->getType()->getAs<RecordType>();
4158  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4159 
4160  LValue LV = EmitLValue(E->getSubExpr());
4161  Address This = LV.getAddress();
4162 
4163  // Perform the derived-to-base conversion
4165  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4166  /*NullCheckValue=*/false, E->getExprLoc());
4167 
4168  // TODO: Support accesses to members of base classes in TBAA. For now, we
4169  // conservatively pretend that the complete object is of the base class
4170  // type.
4171  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4172  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4173  }
4174  case CK_ToUnion:
4175  return EmitAggExprToLValue(E);
4176  case CK_BaseToDerived: {
4177  const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4178  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4179 
4180  LValue LV = EmitLValue(E->getSubExpr());
4181 
4182  // Perform the base-to-derived conversion
4183  Address Derived =
4184  GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4185  E->path_begin(), E->path_end(),
4186  /*NullCheckValue=*/false);
4187 
4188  // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4189  // performed and the object is not of the derived type.
4192  Derived.getPointer(), E->getType());
4193 
4194  if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4195  EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4196  /*MayBeNull=*/false,
4198 
4199  return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4200  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4201  }
4202  case CK_LValueBitCast: {
4203  // This must be a reinterpret_cast (or c-style equivalent).
4204  const auto *CE = cast<ExplicitCastExpr>(E);
4205 
4206  CGM.EmitExplicitCastExprType(CE, this);
4207  LValue LV = EmitLValue(E->getSubExpr());
4209  ConvertType(CE->getTypeAsWritten()));
4210 
4211  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4212  EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4213  /*MayBeNull=*/false,
4215 
4216  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4217  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4218  }
4219  case CK_ObjCObjectLValueCast: {
4220  LValue LV = EmitLValue(E->getSubExpr());
4222  ConvertType(E->getType()));
4223  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4224  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4225  }
4226  case CK_ZeroToOCLQueue:
4227  llvm_unreachable("NULL to OpenCL queue lvalue cast is not valid");
4228  case CK_ZeroToOCLEvent:
4229  llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
4230  }
4231 
4232  llvm_unreachable("Unhandled lvalue cast kind?");
4233 }
4234 
4238 }
4239 
4240 LValue
4243 
4244  llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4245  it = OpaqueLValues.find(e);
4246 
4247  if (it != OpaqueLValues.end())
4248  return it->second;
4249 
4250  assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4251  return EmitLValue(e->getSourceExpr());
4252 }
4253 
4254 RValue
4257 
4258  llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4259  it = OpaqueRValues.find(e);
4260 
4261  if (it != OpaqueRValues.end())
4262  return it->second;
4263 
4264  assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4265  return EmitAnyExpr(e->getSourceExpr());
4266 }
4267 
4269  const FieldDecl *FD,
4270  SourceLocation Loc) {
4271  QualType FT = FD->getType();
4272  LValue FieldLV = EmitLValueForField(LV, FD);
4273  switch (getEvaluationKind(FT)) {
4274  case TEK_Complex:
4275  return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4276  case TEK_Aggregate:
4277  return FieldLV.asAggregateRValue();
4278  case TEK_Scalar:
4279  // This routine is used to load fields one-by-one to perform a copy, so
4280  // don't load reference fields.
4281  if (FD->getType()->isReferenceType())
4282  return RValue::get(FieldLV.getPointer());
4283  return EmitLoadOfLValue(FieldLV, Loc);
4284  }
4285  llvm_unreachable("bad evaluation kind");
4286 }
4287 
4288 //===--------------------------------------------------------------------===//
4289 // Expression Emission
4290 //===--------------------------------------------------------------------===//
4291 
4294  // Builtins never have block type.
4295  if (E->getCallee()->getType()->isBlockPointerType())
4296  return EmitBlockCallExpr(E, ReturnValue);
4297 
4298  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4299  return EmitCXXMemberCallExpr(CE, ReturnValue);
4300 
4301  if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4302  return EmitCUDAKernelCallExpr(CE, ReturnValue);
4303 
4304  if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4305  if (const CXXMethodDecl *MD =
4306  dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4307  return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4308 
4309  CGCallee callee = EmitCallee(E->getCallee());
4310 
4311  if (callee.isBuiltin()) {
4312  return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4313  E, ReturnValue);
4314  }
4315 
4316  if (callee.isPseudoDestructor()) {
4318  }
4319 
4320  return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4321 }
4322 
4323 /// Emit a CallExpr without considering whether it might be a subclass.
4326  CGCallee Callee = EmitCallee(E->getCallee());
4327  return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4328 }
4329 
4331  if (auto builtinID = FD->getBuiltinID()) {
4332  return CGCallee::forBuiltin(builtinID, FD);
4333  }
4334 
4335  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4336  return CGCallee::forDirect(calleePtr, FD);
4337 }
4338 
4340  E = E->IgnoreParens();
4341 
4342  // Look through function-to-pointer decay.
4343  if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4344  if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4345  ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4346  return EmitCallee(ICE->getSubExpr());
4347  }
4348 
4349  // Resolve direct calls.
4350  } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4351  if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4352  return EmitDirectCallee(*this, FD);
4353  }
4354  } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4355  if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4356  EmitIgnoredExpr(ME->getBase());
4357  return EmitDirectCallee(*this, FD);
4358  }
4359 
4360  // Look through template substitutions.
4361  } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4362  return EmitCallee(NTTP->getReplacement());
4363 
4364  // Treat pseudo-destructor calls differently.
4365  } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4366  return CGCallee::forPseudoDestructor(PDE);
4367  }
4368 
4369  // Otherwise, we have an indirect reference.
4370  llvm::Value *calleePtr;
4372  if (auto ptrType = E->getType()->getAs<PointerType>()) {
4373  calleePtr = EmitScalarExpr(E);
4374  functionType = ptrType->getPointeeType();
4375  } else {
4376  functionType = E->getType();
4377  calleePtr = EmitLValue(E).getPointer();
4378  }
4379  assert(functionType->isFunctionType());
4380  CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
4382  CGCallee callee(calleeInfo, calleePtr);
4383  return callee;
4384 }
4385 
4387  // Comma expressions just emit their LHS then their RHS as an l-value.
4388  if (E->getOpcode() == BO_Comma) {
4389  EmitIgnoredExpr(E->getLHS());
4391  return EmitLValue(E->getRHS());
4392  }
4393 
4394  if (E->getOpcode() == BO_PtrMemD ||
4395  E->getOpcode() == BO_PtrMemI)
4397 
4398  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4399 
4400  // Note that in all of these cases, __block variables need the RHS
4401  // evaluated first just in case the variable gets moved by the RHS.
4402 
4403  switch (getEvaluationKind(E->getType())) {
4404  case TEK_Scalar: {
4405  switch (E->getLHS()->getType().getObjCLifetime()) {
4407  return EmitARCStoreStrong(E, /*ignored*/ false).first;
4408 
4410  return EmitARCStoreAutoreleasing(E).first;
4411 
4412  // No reason to do any of these differently.
4413  case Qualifiers::OCL_None:
4415  case Qualifiers::OCL_Weak:
4416  break;
4417  }
4418 
4419  RValue RV = EmitAnyExpr(E->getRHS());
4421  if (RV.isScalar())
4423  EmitStoreThroughLValue(RV, LV);
4424  return LV;
4425  }
4426 
4427  case TEK_Complex:
4428  return EmitComplexAssignmentLValue(E);
4429 
4430  case TEK_Aggregate:
4431  return EmitAggExprToLValue(E);
4432  }
4433  llvm_unreachable("bad evaluation kind");
4434 }
4435 
4437  RValue RV = EmitCallExpr(E);
4438 
4439  if (!RV.isScalar())
4440  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4442 
4443  assert(E->getCallReturnType(getContext())->isReferenceType() &&
4444  "Can't have a scalar return unless the return type is a "
4445  "reference type!");
4446 
4448 }
4449 
4451  // FIXME: This shouldn't require another copy.
4452  return EmitAggExprToLValue(E);
4453 }
4454 
4457  && "binding l-value to type which needs a temporary");
4458  AggValueSlot Slot = CreateAggTemp(E->getType());
4459  EmitCXXConstructExpr(E, Slot);
4460  return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4461 }
4462 
4463 LValue
4466 }
4467 
4470  ConvertType(E->getType()));
4471 }
4472 
4474  return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4476 }
4477 
4478 LValue
4480  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4481  Slot.setExternallyDestructed();
4482  EmitAggExpr(E->getSubExpr(), Slot);
4483  EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4485 }
4486 
4487 LValue
4489  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4490  EmitLambdaExpr(E, Slot);
4492 }
4493 
4495  RValue RV = EmitObjCMessageExpr(E);
4496 
4497  if (!RV.isScalar())
4498  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4500 
4501  assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4502  "Can't have a scalar return unless the return type is a "
4503  "reference type!");
4504 
4506 }
4507 
4509  Address V =
4511  return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4512 }
4513 
4515  const ObjCIvarDecl *Ivar) {
4516  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4517 }
4518 
4520  llvm::Value *BaseValue,
4521  const ObjCIvarDecl *Ivar,
4522  unsigned CVRQualifiers) {
4523  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4524  Ivar, CVRQualifiers);
4525 }
4526 
4528  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4529  llvm::Value *BaseValue = nullptr;
4530  const Expr *BaseExpr = E->getBase();
4531  Qualifiers BaseQuals;
4532  QualType ObjectTy;
4533  if (E->isArrow()) {
4534  BaseValue = EmitScalarExpr(BaseExpr);
4535  ObjectTy = BaseExpr->getType()->getPointeeType();
4536  BaseQuals = ObjectTy.getQualifiers();
4537  } else {
4538  LValue BaseLV = EmitLValue(BaseExpr);
4539  BaseValue = BaseLV.getPointer();
4540  ObjectTy = BaseExpr->getType();
4541  BaseQuals = ObjectTy.getQualifiers();
4542  }
4543 
4544  LValue LV =
4545  EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4546  BaseQuals.getCVRQualifiers());
4547  setObjCGCLValueClass(getContext(), E, LV);
4548  return LV;
4549 }
4550 
4552  // Can only get l-value for message expression returning aggregate type
4553  RValue RV = EmitAnyExprToTemp(E);
4554  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4556 }
4557 
4558 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4560  llvm::Value *Chain) {
4561  // Get the actual function type. The callee type will always be a pointer to
4562  // function type or a block pointer type.
4563  assert(CalleeType->isFunctionPointerType() &&
4564  "Call must have function pointer type!");
4565 
4566  const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
4567 
4568  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4569  // We can only guarantee that a function is called from the correct
4570  // context/function based on the appropriate target attributes,
4571  // so only check in the case where we have both always_inline and target
4572  // since otherwise we could be making a conditional call after a check for
4573  // the proper cpu features (and it won't cause code generation issues due to
4574  // function based code generation).
4575  if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4576  TargetDecl->hasAttr<TargetAttr>())
4577  checkTargetFeatures(E, FD);
4578 
4579  CalleeType = getContext().getCanonicalType(CalleeType);
4580 
4581  auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4582 
4583  CGCallee Callee = OrigCallee;
4584 
4585  if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4586  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4587  if (llvm::Constant *PrefixSig =
4589  SanitizerScope SanScope(this);
4590  // Remove any (C++17) exception specifications, to allow calling e.g. a
4591  // noexcept function through a non-noexcept pointer.
4592  auto ProtoTy =
4594  llvm::Constant *FTRTTIConst =
4595  CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4596  llvm::Type *PrefixStructTyElems[] = {PrefixSig->getType(), Int32Ty};
4597  llvm::StructType *PrefixStructTy = llvm::StructType::get(
4598  CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4599 
4600  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4601 
4602  llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4603  CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4604  llvm::Value *CalleeSigPtr =
4605  Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4606  llvm::Value *CalleeSig =
4607  Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4608  llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4609 
4610  llvm::BasicBlock *Cont = createBasicBlock("cont");
4611  llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4612  Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4613 
4614  EmitBlock(TypeCheck);
4615  llvm::Value *CalleeRTTIPtr =
4616  Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4617  llvm::Value *CalleeRTTIEncoded =
4618  Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4619  llvm::Value *CalleeRTTI =
4620  DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
4621  llvm::Value *CalleeRTTIMatch =
4622  Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4623  llvm::Constant *StaticData[] = {
4625  EmitCheckTypeDescriptor(CalleeType)
4626  };
4627  EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4628  SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4629 
4630  Builder.CreateBr(Cont);
4631  EmitBlock(Cont);
4632  }
4633  }
4634 
4635  const auto *FnType = cast<FunctionType>(PointeeType);
4636 
4637  // If we are checking indirect calls and this call is indirect, check that the
4638  // function pointer is a member of the bit set for the function type.
4639  if (SanOpts.has(SanitizerKind::CFIICall) &&
4640  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4641  SanitizerScope SanScope(this);
4642  EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4643 
4644  llvm::Metadata *MD;
4645  if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
4647  else
4648  MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4649 
4650  llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4651 
4652  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4653  llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4654  llvm::Value *TypeTest = Builder.CreateCall(
4655  CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4656 
4657  auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4658  llvm::Constant *StaticData[] = {
4659  llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4661  EmitCheckTypeDescriptor(QualType(FnType, 0)),
4662  };
4663  if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4664  EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4665  CastedCallee, StaticData);
4666  } else {
4667  EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4668  SanitizerHandler::CFICheckFail, StaticData,
4669  {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4670  }
4671  }
4672 
4673  CallArgList Args;
4674  if (Chain)
4677 
4678  // C++17 requires that we evaluate arguments to a call using assignment syntax
4679  // right-to-left, and that we evaluate arguments to certain other operators
4680  // left-to-right. Note that we allow this to override the order dictated by
4681  // the calling convention on the MS ABI, which means that parameter
4682  // destruction order is not necessarily reverse construction order.
4683  // FIXME: Revisit this based on C++ committee response to unimplementability.
4685  if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4686  if (OCE->isAssignmentOp())
4688  else {
4689  switch (OCE->getOperator()) {
4690  case OO_LessLess:
4691  case OO_GreaterGreater:
4692  case OO_AmpAmp:
4693  case OO_PipePipe:
4694  case OO_Comma:
4695  case OO_ArrowStar:
4697  break;
4698  default:
4699  break;
4700  }
4701  }
4702  }
4703 
4704  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4705  E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4706 
4708  Args, FnType, /*isChainCall=*/Chain);
4709 
4710  // C99 6.5.2.2p6:
4711  // If the expression that denotes the called function has a type
4712  // that does not include a prototype, [the default argument
4713  // promotions are performed]. If the number of arguments does not
4714  // equal the number of parameters, the behavior is undefined. If
4715  // the function is defined with a type that includes a prototype,
4716  // and either the prototype ends with an ellipsis (, ...) or the
4717  // types of the arguments after promotion are not compatible with
4718  // the types of the parameters, the behavior is undefined. If the
4719  // function is defined with a type that does not include a
4720  // prototype, and the types of the arguments after promotion are
4721  // not compatible with those of the parameters after promotion,
4722  // the behavior is undefined [except in some trivial cases].
4723  // That is, in the general case, we should assume that a call
4724  // through an unprototyped function type works like a *non-variadic*
4725  // call. The way we make this work is to cast to the exact type
4726  // of the promoted arguments.
4727  //
4728  // Chain calls use this same code path to add the invisible chain parameter
4729  // to the function type.
4730  if (isa<FunctionNoProtoType>(FnType) || Chain) {
4731  llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4732  CalleeTy = CalleeTy->getPointerTo();
4733 
4734  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4735  CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4736  Callee.setFunctionPointer(CalleePtr);
4737  }
4738 
4739  return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr, E->getExprLoc());
4740 }
4741 
4744  Address BaseAddr = Address::invalid();
4745  if (E->getOpcode() == BO_PtrMemI) {
4746  BaseAddr = EmitPointerWithAlignment(E->getLHS());
4747  } else {
4748  BaseAddr = EmitLValue(E->getLHS()).getAddress();
4749  }
4750 
4751  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4752 
4753  const MemberPointerType *MPT
4754  = E->getRHS()->getType()->getAs<MemberPointerType>();
4755 
4756  LValueBaseInfo BaseInfo;
4757  TBAAAccessInfo TBAAInfo;
4758  Address MemberAddr =
4759  EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
4760  &TBAAInfo);
4761 
4762  return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
4763 }
4764 
4765 /// Given the address of a temporary variable, produce an r-value of
4766 /// its type.
4768  QualType type,
4769  SourceLocation loc) {
4770  LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4771  switch (getEvaluationKind(type)) {
4772  case TEK_Complex:
4773  return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4774  case TEK_Aggregate:
4775  return lvalue.asAggregateRValue();
4776  case TEK_Scalar:
4777  return RValue::get(EmitLoadOfScalar(lvalue, loc));
4778  }
4779  llvm_unreachable("bad evaluation kind");
4780 }
4781 
4782 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4783  assert(Val->getType()->isFPOrFPVectorTy());
4784  if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4785  return;