clang  7.0.0svn
CGExpr.cpp
Go to the documentation of this file.
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  const Twine &Name,
66  llvm::Value *ArraySize,
67  bool CastToDefaultAddrSpace) {
68  auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
69  Alloca->setAlignment(Align.getQuantity());
70  llvm::Value *V = Alloca;
71  // Alloca always returns a pointer in alloca address space, which may
72  // be different from the type defined by the language. For example,
73  // in C++ the auto variables are in the default address space. Therefore
74  // cast alloca to the default address space when necessary.
75  if (CastToDefaultAddrSpace && getASTAllocaAddressSpace() != LangAS::Default) {
76  auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
77  llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
78  // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
79  // otherwise alloca is inserted at the current insertion point of the
80  // builder.
81  if (!ArraySize)
82  Builder.SetInsertPoint(AllocaInsertPt);
85  Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
86  }
87 
88  return Address(V, Align);
89 }
90 
91 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
92 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
93 /// insertion point of the builder.
95  const Twine &Name,
96  llvm::Value *ArraySize) {
97  if (ArraySize)
98  return Builder.CreateAlloca(Ty, ArraySize, Name);
99  return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
100  ArraySize, Name, AllocaInsertPt);
101 }
102 
103 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
104 /// default alignment of the corresponding LLVM type, which is *not*
105 /// guaranteed to be related in any way to the expected alignment of
106 /// an AST type that might have been lowered to Ty.
108  const Twine &Name) {
109  CharUnits Align =
110  CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
111  return CreateTempAlloca(Ty, Align, Name);
112 }
113 
115  assert(isa<llvm::AllocaInst>(Var.getPointer()));
116  auto *Store = new llvm::StoreInst(Init, Var.getPointer());
117  Store->setAlignment(Var.getAlignment().getQuantity());
118  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
119  Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
120 }
121 
124  return CreateTempAlloca(ConvertType(Ty), Align, Name);
125 }
126 
128  bool CastToDefaultAddrSpace) {
129  // FIXME: Should we prefer the preferred type alignment here?
130  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name,
131  CastToDefaultAddrSpace);
132 }
133 
135  const Twine &Name,
136  bool CastToDefaultAddrSpace) {
137  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name, nullptr,
138  CastToDefaultAddrSpace);
139 }
140 
141 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
142 /// expression and compare the result against zero, returning an Int1Ty value.
144  PGO.setCurrentStmt(E);
145  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
146  llvm::Value *MemPtr = EmitScalarExpr(E);
147  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
148  }
149 
150  QualType BoolTy = getContext().BoolTy;
151  SourceLocation Loc = E->getExprLoc();
152  if (!E->getType()->isAnyComplexType())
153  return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
154 
155  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
156  Loc);
157 }
158 
159 /// EmitIgnoredExpr - Emit code to compute the specified expression,
160 /// ignoring the result.
162  if (E->isRValue())
163  return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
164 
165  // Just emit it as an l-value and drop the result.
166  EmitLValue(E);
167 }
168 
169 /// EmitAnyExpr - Emit code to compute the specified expression which
170 /// can have any type. The result is returned as an RValue struct.
171 /// If this is an aggregate expression, AggSlot indicates where the
172 /// result should be returned.
174  AggValueSlot aggSlot,
175  bool ignoreResult) {
176  switch (getEvaluationKind(E->getType())) {
177  case TEK_Scalar:
178  return RValue::get(EmitScalarExpr(E, ignoreResult));
179  case TEK_Complex:
180  return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
181  case TEK_Aggregate:
182  if (!ignoreResult && aggSlot.isIgnored())
183  aggSlot = CreateAggTemp(E->getType(), "agg-temp");
184  EmitAggExpr(E, aggSlot);
185  return aggSlot.asRValue();
186  }
187  llvm_unreachable("bad evaluation kind");
188 }
189 
190 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
191 /// always be accessible even if no aggregate location is provided.
194 
196  AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
197  return EmitAnyExpr(E, AggSlot);
198 }
199 
200 /// EmitAnyExprToMem - Evaluate an expression into a given memory
201 /// location.
203  Address Location,
204  Qualifiers Quals,
205  bool IsInit) {
206  // FIXME: This function should take an LValue as an argument.
207  switch (getEvaluationKind(E->getType())) {
208  case TEK_Complex:
210  /*isInit*/ false);
211  return;
212 
213  case TEK_Aggregate: {
214  EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
217  AggValueSlot::IsAliased_t(!IsInit),
219  return;
220  }
221 
222  case TEK_Scalar: {
223  RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
224  LValue LV = MakeAddrLValue(Location, E->getType());
225  EmitStoreThroughLValue(RV, LV);
226  return;
227  }
228  }
229  llvm_unreachable("bad evaluation kind");
230 }
231 
232 static void
234  const Expr *E, Address ReferenceTemporary) {
235  // Objective-C++ ARC:
236  // If we are binding a reference to a temporary that has ownership, we
237  // need to perform retain/release operations on the temporary.
238  //
239  // FIXME: This should be looking at E, not M.
240  if (auto Lifetime = M->getType().getObjCLifetime()) {
241  switch (Lifetime) {
244  // Carry on to normal cleanup handling.
245  break;
246 
248  // Nothing to do; cleaned up by an autorelease pool.
249  return;
250 
253  switch (StorageDuration Duration = M->getStorageDuration()) {
254  case SD_Static:
255  // Note: we intentionally do not register a cleanup to release
256  // the object on program termination.
257  return;
258 
259  case SD_Thread:
260  // FIXME: We should probably register a cleanup in this case.
261  return;
262 
263  case SD_Automatic:
264  case SD_FullExpression:
267  if (Lifetime == Qualifiers::OCL_Strong) {
268  const ValueDecl *VD = M->getExtendingDecl();
269  bool Precise =
270  VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
271  CleanupKind = CGF.getARCCleanupKind();
272  Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
274  } else {
275  // __weak objects always get EH cleanups; otherwise, exceptions
276  // could cause really nasty crashes instead of mere leaks.
277  CleanupKind = NormalAndEHCleanup;
279  }
280  if (Duration == SD_FullExpression)
281  CGF.pushDestroy(CleanupKind, ReferenceTemporary,
282  M->getType(), *Destroy,
283  CleanupKind & EHCleanup);
284  else
285  CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
286  M->getType(),
287  *Destroy, CleanupKind & EHCleanup);
288  return;
289 
290  case SD_Dynamic:
291  llvm_unreachable("temporary cannot have dynamic storage duration");
292  }
293  llvm_unreachable("unknown storage duration");
294  }
295  }
296 
297  CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
298  if (const RecordType *RT =
300  // Get the destructor for the reference temporary.
301  auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
302  if (!ClassDecl->hasTrivialDestructor())
303  ReferenceTemporaryDtor = ClassDecl->getDestructor();
304  }
305 
306  if (!ReferenceTemporaryDtor)
307  return;
308 
309  // Call the destructor for the temporary.
310  switch (M->getStorageDuration()) {
311  case SD_Static:
312  case SD_Thread: {
313  llvm::Constant *CleanupFn;
314  llvm::Constant *CleanupArg;
315  if (E->getType()->isArrayType()) {
316  CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
317  ReferenceTemporary, E->getType(),
319  dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
320  CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
321  } else {
322  CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
324  CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
325  }
327  CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
328  break;
329  }
330 
331  case SD_FullExpression:
332  CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
334  CGF.getLangOpts().Exceptions);
335  break;
336 
337  case SD_Automatic:
339  ReferenceTemporary, E->getType(),
341  CGF.getLangOpts().Exceptions);
342  break;
343 
344  case SD_Dynamic:
345  llvm_unreachable("temporary cannot have dynamic storage duration");
346  }
347 }
348 
350  const MaterializeTemporaryExpr *M,
351  const Expr *Inner) {
352  auto &TCG = CGF.getTargetHooks();
353  switch (M->getStorageDuration()) {
354  case SD_FullExpression:
355  case SD_Automatic: {
356  // If we have a constant temporary array or record try to promote it into a
357  // constant global under the same rules a normal constant would've been
358  // promoted. This is easier on the optimizer and generally emits fewer
359  // instructions.
360  QualType Ty = Inner->getType();
361  if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
362  (Ty->isArrayType() || Ty->isRecordType()) &&
363  CGF.CGM.isTypeConstant(Ty, true))
364  if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
365  if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
366  auto AS = AddrSpace.getValue();
367  auto *GV = new llvm::GlobalVariable(
368  CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
369  llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
370  llvm::GlobalValue::NotThreadLocal,
372  CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
373  GV->setAlignment(alignment.getQuantity());
374  llvm::Constant *C = GV;
375  if (AS != LangAS::Default)
376  C = TCG.performAddrSpaceCast(
377  CGF.CGM, GV, AS, LangAS::Default,
378  GV->getValueType()->getPointerTo(
380  // FIXME: Should we put the new global into a COMDAT?
381  return Address(C, alignment);
382  }
383  }
384  return CGF.CreateMemTemp(Ty, "ref.tmp");
385  }
386  case SD_Thread:
387  case SD_Static:
388  return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
389 
390  case SD_Dynamic:
391  llvm_unreachable("temporary can't have dynamic storage duration");
392  }
393  llvm_unreachable("unknown storage duration");
394 }
395 
398  const Expr *E = M->GetTemporaryExpr();
399 
400  // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
401  // as that will cause the lifetime adjustment to be lost for ARC
402  auto ownership = M->getType().getObjCLifetime();
403  if (ownership != Qualifiers::OCL_None &&
404  ownership != Qualifiers::OCL_ExplicitNone) {
405  Address Object = createReferenceTemporary(*this, M, E);
406  if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
407  Object = Address(llvm::ConstantExpr::getBitCast(Var,
409  ->getPointerTo(Object.getAddressSpace())),
410  Object.getAlignment());
411 
412  // createReferenceTemporary will promote the temporary to a global with a
413  // constant initializer if it can. It can only do this to a value of
414  // ARC-manageable type if the value is global and therefore "immune" to
415  // ref-counting operations. Therefore we have no need to emit either a
416  // dynamic initialization or a cleanup and we can just return the address
417  // of the temporary.
418  if (Var->hasInitializer())
419  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
420 
421  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
422  }
423  LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
425 
426  switch (getEvaluationKind(E->getType())) {
427  default: llvm_unreachable("expected scalar or aggregate expression");
428  case TEK_Scalar:
429  EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
430  break;
431  case TEK_Aggregate: {
433  E->getType().getQualifiers(),
438  break;
439  }
440  }
441 
442  pushTemporaryCleanup(*this, M, E, Object);
443  return RefTempDst;
444  }
445 
448  E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
449 
450  for (const auto &Ignored : CommaLHSs)
451  EmitIgnoredExpr(Ignored);
452 
453  if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
454  if (opaque->getType()->isRecordType()) {
455  assert(Adjustments.empty());
456  return EmitOpaqueValueLValue(opaque);
457  }
458  }
459 
460  // Create and initialize the reference temporary.
461  Address Object = createReferenceTemporary(*this, M, E);
462  if (auto *Var = dyn_cast<llvm::GlobalVariable>(
463  Object.getPointer()->stripPointerCasts())) {
464  Object = Address(llvm::ConstantExpr::getBitCast(
465  cast<llvm::Constant>(Object.getPointer()),
466  ConvertTypeForMem(E->getType())->getPointerTo()),
467  Object.getAlignment());
468  // If the temporary is a global and has a constant initializer or is a
469  // constant temporary that we promoted to a global, we may have already
470  // initialized it.
471  if (!Var->hasInitializer()) {
472  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
473  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
474  }
475  } else {
476  switch (M->getStorageDuration()) {
477  case SD_Automatic:
478  case SD_FullExpression:
479  if (auto *Size = EmitLifetimeStart(
480  CGM.getDataLayout().getTypeAllocSize(Object.getElementType()),
481  Object.getPointer())) {
482  if (M->getStorageDuration() == SD_Automatic)
483  pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
484  Object, Size);
485  else
486  pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Object,
487  Size);
488  }
489  break;
490  default:
491  break;
492  }
493  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
494  }
495  pushTemporaryCleanup(*this, M, E, Object);
496 
497  // Perform derived-to-base casts and/or field accesses, to get from the
498  // temporary object we created (and, potentially, for which we extended
499  // the lifetime) to the subobject we're binding the reference to.
500  for (unsigned I = Adjustments.size(); I != 0; --I) {
501  SubobjectAdjustment &Adjustment = Adjustments[I-1];
502  switch (Adjustment.Kind) {
504  Object =
506  Adjustment.DerivedToBase.BasePath->path_begin(),
507  Adjustment.DerivedToBase.BasePath->path_end(),
508  /*NullCheckValue=*/ false, E->getExprLoc());
509  break;
510 
513  LV = EmitLValueForField(LV, Adjustment.Field);
514  assert(LV.isSimple() &&
515  "materialized temporary field is not a simple lvalue");
516  Object = LV.getAddress();
517  break;
518  }
519 
521  llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
522  Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
523  Adjustment.Ptr.MPT);
524  break;
525  }
526  }
527  }
528 
529  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
530 }
531 
532 RValue
534  // Emit the expression as an lvalue.
535  LValue LV = EmitLValue(E);
536  assert(LV.isSimple());
537  llvm::Value *Value = LV.getPointer();
538 
539  if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
540  // C++11 [dcl.ref]p5 (as amended by core issue 453):
541  // If a glvalue to which a reference is directly bound designates neither
542  // an existing object or function of an appropriate type nor a region of
543  // storage of suitable size and alignment to contain an object of the
544  // reference's type, the behavior is undefined.
545  QualType Ty = E->getType();
547  }
548 
549  return RValue::get(Value);
550 }
551 
552 
553 /// getAccessedFieldNo - Given an encoded value and a result number, return the
554 /// input field number being accessed.
556  const llvm::Constant *Elts) {
557  return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
558  ->getZExtValue();
559 }
560 
561 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
563  llvm::Value *High) {
564  llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
565  llvm::Value *K47 = Builder.getInt64(47);
566  llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
567  llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
568  llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
569  llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
570  return Builder.CreateMul(B1, KMul);
571 }
572 
574  return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
576 }
577 
579  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
580  return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
581  (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
582  TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
584 }
585 
587  return SanOpts.has(SanitizerKind::Null) |
588  SanOpts.has(SanitizerKind::Alignment) |
589  SanOpts.has(SanitizerKind::ObjectSize) |
590  SanOpts.has(SanitizerKind::Vptr);
591 }
592 
594  llvm::Value *Ptr, QualType Ty,
595  CharUnits Alignment,
596  SanitizerSet SkippedChecks) {
598  return;
599 
600  // Don't check pointers outside the default address space. The null check
601  // isn't correct, the object-size check isn't supported by LLVM, and we can't
602  // communicate the addresses to the runtime handler for the vptr check.
603  if (Ptr->getType()->getPointerAddressSpace())
604  return;
605 
606  // Don't check pointers to volatile data. The behavior here is implementation-
607  // defined.
608  if (Ty.isVolatileQualified())
609  return;
610 
611  SanitizerScope SanScope(this);
612 
614  llvm::BasicBlock *Done = nullptr;
615 
616  // Quickly determine whether we have a pointer to an alloca. It's possible
617  // to skip null checks, and some alignment checks, for these pointers. This
618  // can reduce compile-time significantly.
619  auto PtrToAlloca =
620  dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
621 
622  llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
623  llvm::Value *IsNonNull = nullptr;
624  bool IsGuaranteedNonNull =
625  SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
626  bool AllowNullPointers = isNullPointerAllowed(TCK);
627  if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
628  !IsGuaranteedNonNull) {
629  // The glvalue must not be an empty glvalue.
630  IsNonNull = Builder.CreateIsNotNull(Ptr);
631 
632  // The IR builder can constant-fold the null check if the pointer points to
633  // a constant.
634  IsGuaranteedNonNull = IsNonNull == True;
635 
636  // Skip the null check if the pointer is known to be non-null.
637  if (!IsGuaranteedNonNull) {
638  if (AllowNullPointers) {
639  // When performing pointer casts, it's OK if the value is null.
640  // Skip the remaining checks in that case.
641  Done = createBasicBlock("null");
642  llvm::BasicBlock *Rest = createBasicBlock("not.null");
643  Builder.CreateCondBr(IsNonNull, Rest, Done);
644  EmitBlock(Rest);
645  } else {
646  Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
647  }
648  }
649  }
650 
651  if (SanOpts.has(SanitizerKind::ObjectSize) &&
652  !SkippedChecks.has(SanitizerKind::ObjectSize) &&
653  !Ty->isIncompleteType()) {
654  uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
655 
656  // The glvalue must refer to a large enough storage region.
657  // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
658  // to check this.
659  // FIXME: Get object address space
660  llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
661  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
662  llvm::Value *Min = Builder.getFalse();
663  llvm::Value *NullIsUnknown = Builder.getFalse();
664  llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
665  llvm::Value *LargeEnough = Builder.CreateICmpUGE(
666  Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown}),
667  llvm::ConstantInt::get(IntPtrTy, Size));
668  Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
669  }
670 
671  uint64_t AlignVal = 0;
672  llvm::Value *PtrAsInt = nullptr;
673 
674  if (SanOpts.has(SanitizerKind::Alignment) &&
675  !SkippedChecks.has(SanitizerKind::Alignment)) {
676  AlignVal = Alignment.getQuantity();
677  if (!Ty->isIncompleteType() && !AlignVal)
678  AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
679 
680  // The glvalue must be suitably aligned.
681  if (AlignVal > 1 &&
682  (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
683  PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
684  llvm::Value *Align = Builder.CreateAnd(
685  PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
686  llvm::Value *Aligned =
687  Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
688  if (Aligned != True)
689  Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
690  }
691  }
692 
693  if (Checks.size() > 0) {
694  // Make sure we're not losing information. Alignment needs to be a power of
695  // 2
696  assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
697  llvm::Constant *StaticData[] = {
699  llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
700  llvm::ConstantInt::get(Int8Ty, TCK)};
701  EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
702  PtrAsInt ? PtrAsInt : Ptr);
703  }
704 
705  // If possible, check that the vptr indicates that there is a subobject of
706  // type Ty at offset zero within this object.
707  //
708  // C++11 [basic.life]p5,6:
709  // [For storage which does not refer to an object within its lifetime]
710  // The program has undefined behavior if:
711  // -- the [pointer or glvalue] is used to access a non-static data member
712  // or call a non-static member function
713  if (SanOpts.has(SanitizerKind::Vptr) &&
714  !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
715  // Ensure that the pointer is non-null before loading it. If there is no
716  // compile-time guarantee, reuse the run-time null check or emit a new one.
717  if (!IsGuaranteedNonNull) {
718  if (!IsNonNull)
719  IsNonNull = Builder.CreateIsNotNull(Ptr);
720  if (!Done)
721  Done = createBasicBlock("vptr.null");
722  llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
723  Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
724  EmitBlock(VptrNotNull);
725  }
726 
727  // Compute a hash of the mangled name of the type.
728  //
729  // FIXME: This is not guaranteed to be deterministic! Move to a
730  // fingerprinting mechanism once LLVM provides one. For the time
731  // being the implementation happens to be deterministic.
732  SmallString<64> MangledName;
733  llvm::raw_svector_ostream Out(MangledName);
735  Out);
736 
737  // Blacklist based on the mangled type.
739  SanitizerKind::Vptr, Out.str())) {
740  llvm::hash_code TypeHash = hash_value(Out.str());
741 
742  // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
743  llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
744  llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
745  Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
746  llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
747  llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
748 
749  llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
750  Hash = Builder.CreateTrunc(Hash, IntPtrTy);
751 
752  // Look the hash up in our cache.
753  const int CacheSize = 128;
754  llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
756  "__ubsan_vptr_type_cache");
757  llvm::Value *Slot = Builder.CreateAnd(Hash,
758  llvm::ConstantInt::get(IntPtrTy,
759  CacheSize-1));
760  llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
761  llvm::Value *CacheVal =
762  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
763  getPointerAlign());
764 
765  // If the hash isn't in the cache, call a runtime handler to perform the
766  // hard work of checking whether the vptr is for an object of the right
767  // type. This will either fill in the cache and return, or produce a
768  // diagnostic.
769  llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
770  llvm::Constant *StaticData[] = {
774  llvm::ConstantInt::get(Int8Ty, TCK)
775  };
776  llvm::Value *DynamicData[] = { Ptr, Hash };
777  EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
778  SanitizerHandler::DynamicTypeCacheMiss, StaticData,
779  DynamicData);
780  }
781  }
782 
783  if (Done) {
784  Builder.CreateBr(Done);
785  EmitBlock(Done);
786  }
787 }
788 
789 /// Determine whether this expression refers to a flexible array member in a
790 /// struct. We disable array bounds checks for such members.
791 static bool isFlexibleArrayMemberExpr(const Expr *E) {
792  // For compatibility with existing code, we treat arrays of length 0 or
793  // 1 as flexible array members.
794  const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
795  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
796  if (CAT->getSize().ugt(1))
797  return false;
798  } else if (!isa<IncompleteArrayType>(AT))
799  return false;
800 
801  E = E->IgnoreParens();
802 
803  // A flexible array member must be the last member in the class.
804  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
805  // FIXME: If the base type of the member expr is not FD->getParent(),
806  // this should not be treated as a flexible array member access.
807  if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
809  DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
810  return ++FI == FD->getParent()->field_end();
811  }
812  } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
813  return IRE->getDecl()->getNextIvar() == nullptr;
814  }
815 
816  return false;
817 }
818 
820  QualType EltTy) {
821  ASTContext &C = getContext();
822  uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
823  if (!EltSize)
824  return nullptr;
825 
826  auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
827  if (!ArrayDeclRef)
828  return nullptr;
829 
830  auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
831  if (!ParamDecl)
832  return nullptr;
833 
834  auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
835  if (!POSAttr)
836  return nullptr;
837 
838  // Don't load the size if it's a lower bound.
839  int POSType = POSAttr->getType();
840  if (POSType != 0 && POSType != 1)
841  return nullptr;
842 
843  // Find the implicit size parameter.
844  auto PassedSizeIt = SizeArguments.find(ParamDecl);
845  if (PassedSizeIt == SizeArguments.end())
846  return nullptr;
847 
848  const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
849  assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
850  Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
851  llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
852  C.getSizeType(), E->getExprLoc());
853  llvm::Value *SizeOfElement =
854  llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
855  return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
856 }
857 
858 /// If Base is known to point to the start of an array, return the length of
859 /// that array. Return 0 if the length cannot be determined.
861  CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
862  // For the vector indexing extension, the bound is the number of elements.
863  if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
864  IndexedType = Base->getType();
865  return CGF.Builder.getInt32(VT->getNumElements());
866  }
867 
868  Base = Base->IgnoreParens();
869 
870  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
871  if (CE->getCastKind() == CK_ArrayToPointerDecay &&
872  !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
873  IndexedType = CE->getSubExpr()->getType();
874  const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
875  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
876  return CGF.Builder.getInt(CAT->getSize());
877  else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
878  return CGF.getVLASize(VAT).NumElts;
879  // Ignore pass_object_size here. It's not applicable on decayed pointers.
880  }
881  }
882 
883  QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
884  if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
885  IndexedType = Base->getType();
886  return POS;
887  }
888 
889  return nullptr;
890 }
891 
893  llvm::Value *Index, QualType IndexType,
894  bool Accessed) {
895  assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
896  "should not be called unless adding bounds checks");
897  SanitizerScope SanScope(this);
898 
899  QualType IndexedType;
900  llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
901  if (!Bound)
902  return;
903 
904  bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
905  llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
906  llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
907 
908  llvm::Constant *StaticData[] = {
910  EmitCheckTypeDescriptor(IndexedType),
911  EmitCheckTypeDescriptor(IndexType)
912  };
913  llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
914  : Builder.CreateICmpULE(IndexVal, BoundVal);
915  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
916  SanitizerHandler::OutOfBounds, StaticData, Index);
917 }
918 
919 
922  bool isInc, bool isPre) {
923  ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
924 
925  llvm::Value *NextVal;
926  if (isa<llvm::IntegerType>(InVal.first->getType())) {
927  uint64_t AmountVal = isInc ? 1 : -1;
928  NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
929 
930  // Add the inc/dec to the real part.
931  NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
932  } else {
933  QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
934  llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
935  if (!isInc)
936  FVal.changeSign();
937  NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
938 
939  // Add the inc/dec to the real part.
940  NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
941  }
942 
943  ComplexPairTy IncVal(NextVal, InVal.second);
944 
945  // Store the updated result through the lvalue.
946  EmitStoreOfComplex(IncVal, LV, /*init*/ false);
947 
948  // If this is a postinc, return the value read from memory, otherwise use the
949  // updated value.
950  return isPre ? IncVal : InVal;
951 }
952 
954  CodeGenFunction *CGF) {
955  // Bind VLAs in the cast type.
956  if (CGF && E->getType()->isVariablyModifiedType())
958 
959  if (CGDebugInfo *DI = getModuleDebugInfo())
960  DI->EmitExplicitCastType(E->getType());
961 }
962 
963 //===----------------------------------------------------------------------===//
964 // LValue Expression Emission
965 //===----------------------------------------------------------------------===//
966 
967 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
968 /// derive a more accurate bound on the alignment of the pointer.
970  LValueBaseInfo *BaseInfo,
971  TBAAAccessInfo *TBAAInfo) {
972  // We allow this with ObjC object pointers because of fragile ABIs.
973  assert(E->getType()->isPointerType() ||
975  E = E->IgnoreParens();
976 
977  // Casts:
978  if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
979  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
980  CGM.EmitExplicitCastExprType(ECE, this);
981 
982  switch (CE->getCastKind()) {
983  // Non-converting casts (but not C's implicit conversion from void*).
984  case CK_BitCast:
985  case CK_NoOp:
986  case CK_AddressSpaceConversion:
987  if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
988  if (PtrTy->getPointeeType()->isVoidType())
989  break;
990 
991  LValueBaseInfo InnerBaseInfo;
992  TBAAAccessInfo InnerTBAAInfo;
993  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
994  &InnerBaseInfo,
995  &InnerTBAAInfo);
996  if (BaseInfo) *BaseInfo = InnerBaseInfo;
997  if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
998 
999  if (isa<ExplicitCastExpr>(CE)) {
1000  LValueBaseInfo TargetTypeBaseInfo;
1001  TBAAAccessInfo TargetTypeTBAAInfo;
1002  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1003  &TargetTypeBaseInfo,
1004  &TargetTypeTBAAInfo);
1005  if (TBAAInfo)
1006  *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1007  TargetTypeTBAAInfo);
1008  // If the source l-value is opaque, honor the alignment of the
1009  // casted-to type.
1010  if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1011  if (BaseInfo)
1012  BaseInfo->mergeForCast(TargetTypeBaseInfo);
1013  Addr = Address(Addr.getPointer(), Align);
1014  }
1015  }
1016 
1017  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1018  CE->getCastKind() == CK_BitCast) {
1019  if (auto PT = E->getType()->getAs<PointerType>())
1020  EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1021  /*MayBeNull=*/true,
1023  CE->getLocStart());
1024  }
1025  return CE->getCastKind() != CK_AddressSpaceConversion
1026  ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1028  ConvertType(E->getType()));
1029  }
1030  break;
1031 
1032  // Array-to-pointer decay.
1033  case CK_ArrayToPointerDecay:
1034  return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1035 
1036  // Derived-to-base conversions.
1037  case CK_UncheckedDerivedToBase:
1038  case CK_DerivedToBase: {
1039  // TODO: Support accesses to members of base classes in TBAA. For now, we
1040  // conservatively pretend that the complete object is of the base class
1041  // type.
1042  if (TBAAInfo)
1043  *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1044  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1045  auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1046  return GetAddressOfBaseClass(Addr, Derived,
1047  CE->path_begin(), CE->path_end(),
1049  CE->getExprLoc());
1050  }
1051 
1052  // TODO: Is there any reason to treat base-to-derived conversions
1053  // specially?
1054  default:
1055  break;
1056  }
1057  }
1058 
1059  // Unary &.
1060  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1061  if (UO->getOpcode() == UO_AddrOf) {
1062  LValue LV = EmitLValue(UO->getSubExpr());
1063  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1064  if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1065  return LV.getAddress();
1066  }
1067  }
1068 
1069  // TODO: conditional operators, comma.
1070 
1071  // Otherwise, use the alignment of the type.
1072  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1073  TBAAInfo);
1074  return Address(EmitScalarExpr(E), Align);
1075 }
1076 
1078  if (Ty->isVoidType())
1079  return RValue::get(nullptr);
1080 
1081  switch (getEvaluationKind(Ty)) {
1082  case TEK_Complex: {
1083  llvm::Type *EltTy =
1085  llvm::Value *U = llvm::UndefValue::get(EltTy);
1086  return RValue::getComplex(std::make_pair(U, U));
1087  }
1088 
1089  // If this is a use of an undefined aggregate type, the aggregate must have an
1090  // identifiable address. Just because the contents of the value are undefined
1091  // doesn't mean that the address can't be taken and compared.
1092  case TEK_Aggregate: {
1093  Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1094  return RValue::getAggregate(DestPtr);
1095  }
1096 
1097  case TEK_Scalar:
1098  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1099  }
1100  llvm_unreachable("bad evaluation kind");
1101 }
1102 
1104  const char *Name) {
1105  ErrorUnsupported(E, Name);
1106  return GetUndefRValue(E->getType());
1107 }
1108 
1110  const char *Name) {
1111  ErrorUnsupported(E, Name);
1112  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1113  return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1114  E->getType());
1115 }
1116 
1118  const Expr *Base = Obj;
1119  while (!isa<CXXThisExpr>(Base)) {
1120  // The result of a dynamic_cast can be null.
1121  if (isa<CXXDynamicCastExpr>(Base))
1122  return false;
1123 
1124  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1125  Base = CE->getSubExpr();
1126  } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1127  Base = PE->getSubExpr();
1128  } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1129  if (UO->getOpcode() == UO_Extension)
1130  Base = UO->getSubExpr();
1131  else
1132  return false;
1133  } else {
1134  return false;
1135  }
1136  }
1137  return true;
1138 }
1139 
1141  LValue LV;
1142  if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1143  LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1144  else
1145  LV = EmitLValue(E);
1146  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1147  SanitizerSet SkippedChecks;
1148  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1149  bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1150  if (IsBaseCXXThis)
1151  SkippedChecks.set(SanitizerKind::Alignment, true);
1152  if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1153  SkippedChecks.set(SanitizerKind::Null, true);
1154  }
1155  EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1156  E->getType(), LV.getAlignment(), SkippedChecks);
1157  }
1158  return LV;
1159 }
1160 
1161 /// EmitLValue - Emit code to compute a designator that specifies the location
1162 /// of the expression.
1163 ///
1164 /// This can return one of two things: a simple address or a bitfield reference.
1165 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1166 /// an LLVM pointer type.
1167 ///
1168 /// If this returns a bitfield reference, nothing about the pointee type of the
1169 /// LLVM value is known: For example, it may not be a pointer to an integer.
1170 ///
1171 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1172 /// this method guarantees that the returned pointer type will point to an LLVM
1173 /// type of the same size of the lvalue's type. If the lvalue has a variable
1174 /// length type, this is not possible.
1175 ///
1177  ApplyDebugLocation DL(*this, E);
1178  switch (E->getStmtClass()) {
1179  default: return EmitUnsupportedLValue(E, "l-value expression");
1180 
1181  case Expr::ObjCPropertyRefExprClass:
1182  llvm_unreachable("cannot emit a property reference directly");
1183 
1184  case Expr::ObjCSelectorExprClass:
1185  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1186  case Expr::ObjCIsaExprClass:
1187  return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1188  case Expr::BinaryOperatorClass:
1189  return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1190  case Expr::CompoundAssignOperatorClass: {
1191  QualType Ty = E->getType();
1192  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1193  Ty = AT->getValueType();
1194  if (!Ty->isAnyComplexType())
1195  return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1196  return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1197  }
1198  case Expr::CallExprClass:
1199  case Expr::CXXMemberCallExprClass:
1200  case Expr::CXXOperatorCallExprClass:
1201  case Expr::UserDefinedLiteralClass:
1202  return EmitCallExprLValue(cast<CallExpr>(E));
1203  case Expr::VAArgExprClass:
1204  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1205  case Expr::DeclRefExprClass:
1206  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1207  case Expr::ParenExprClass:
1208  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1209  case Expr::GenericSelectionExprClass:
1210  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1211  case Expr::PredefinedExprClass:
1212  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1213  case Expr::StringLiteralClass:
1214  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1215  case Expr::ObjCEncodeExprClass:
1216  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1217  case Expr::PseudoObjectExprClass:
1218  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1219  case Expr::InitListExprClass:
1220  return EmitInitListLValue(cast<InitListExpr>(E));
1221  case Expr::CXXTemporaryObjectExprClass:
1222  case Expr::CXXConstructExprClass:
1223  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1224  case Expr::CXXBindTemporaryExprClass:
1225  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1226  case Expr::CXXUuidofExprClass:
1227  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1228  case Expr::LambdaExprClass:
1229  return EmitLambdaLValue(cast<LambdaExpr>(E));
1230 
1231  case Expr::ExprWithCleanupsClass: {
1232  const auto *cleanups = cast<ExprWithCleanups>(E);
1233  enterFullExpression(cleanups);
1234  RunCleanupsScope Scope(*this);
1235  LValue LV = EmitLValue(cleanups->getSubExpr());
1236  if (LV.isSimple()) {
1237  // Defend against branches out of gnu statement expressions surrounded by
1238  // cleanups.
1239  llvm::Value *V = LV.getPointer();
1240  Scope.ForceCleanup({&V});
1241  return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1242  getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1243  }
1244  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1245  // bitfield lvalue or some other non-simple lvalue?
1246  return LV;
1247  }
1248 
1249  case Expr::CXXDefaultArgExprClass:
1250  return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1251  case Expr::CXXDefaultInitExprClass: {
1253  return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1254  }
1255  case Expr::CXXTypeidExprClass:
1256  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1257 
1258  case Expr::ObjCMessageExprClass:
1259  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1260  case Expr::ObjCIvarRefExprClass:
1261  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1262  case Expr::StmtExprClass:
1263  return EmitStmtExprLValue(cast<StmtExpr>(E));
1264  case Expr::UnaryOperatorClass:
1265  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1266  case Expr::ArraySubscriptExprClass:
1267  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1268  case Expr::OMPArraySectionExprClass:
1269  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1270  case Expr::ExtVectorElementExprClass:
1271  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1272  case Expr::MemberExprClass:
1273  return EmitMemberExpr(cast<MemberExpr>(E));
1274  case Expr::CompoundLiteralExprClass:
1275  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1276  case Expr::ConditionalOperatorClass:
1277  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1278  case Expr::BinaryConditionalOperatorClass:
1279  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1280  case Expr::ChooseExprClass:
1281  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1282  case Expr::OpaqueValueExprClass:
1283  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1284  case Expr::SubstNonTypeTemplateParmExprClass:
1285  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1286  case Expr::ImplicitCastExprClass:
1287  case Expr::CStyleCastExprClass:
1288  case Expr::CXXFunctionalCastExprClass:
1289  case Expr::CXXStaticCastExprClass:
1290  case Expr::CXXDynamicCastExprClass:
1291  case Expr::CXXReinterpretCastExprClass:
1292  case Expr::CXXConstCastExprClass:
1293  case Expr::ObjCBridgedCastExprClass:
1294  return EmitCastLValue(cast<CastExpr>(E));
1295 
1296  case Expr::MaterializeTemporaryExprClass:
1297  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1298 
1299  case Expr::CoawaitExprClass:
1300  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1301  case Expr::CoyieldExprClass:
1302  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1303  }
1304 }
1305 
1306 /// Given an object of the given canonical type, can we safely copy a
1307 /// value out of it based on its initializer?
1309  assert(type.isCanonical());
1310  assert(!type->isReferenceType());
1311 
1312  // Must be const-qualified but non-volatile.
1313  Qualifiers qs = type.getLocalQualifiers();
1314  if (!qs.hasConst() || qs.hasVolatile()) return false;
1315 
1316  // Otherwise, all object types satisfy this except C++ classes with
1317  // mutable subobjects or non-trivial copy/destroy behavior.
1318  if (const auto *RT = dyn_cast<RecordType>(type))
1319  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1320  if (RD->hasMutableFields() || !RD->isTrivial())
1321  return false;
1322 
1323  return true;
1324 }
1325 
1326 /// Can we constant-emit a load of a reference to a variable of the
1327 /// given type? This is different from predicates like
1328 /// Decl::isUsableInConstantExpressions because we do want it to apply
1329 /// in situations that don't necessarily satisfy the language's rules
1330 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1331 /// to do this with const float variables even if those variables
1332 /// aren't marked 'constexpr'.
1338 };
1340  type = type.getCanonicalType();
1341  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1342  if (isConstantEmittableObjectType(ref->getPointeeType()))
1343  return CEK_AsValueOrReference;
1344  return CEK_AsReferenceOnly;
1345  }
1347  return CEK_AsValueOnly;
1348  return CEK_None;
1349 }
1350 
1351 /// Try to emit a reference to the given value without producing it as
1352 /// an l-value. This is actually more than an optimization: we can't
1353 /// produce an l-value for variables that we never actually captured
1354 /// in a block or lambda, which means const int variables or constexpr
1355 /// literals or similar.
1358  ValueDecl *value = refExpr->getDecl();
1359 
1360  // The value needs to be an enum constant or a constant variable.
1362  if (isa<ParmVarDecl>(value)) {
1363  CEK = CEK_None;
1364  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1365  CEK = checkVarTypeForConstantEmission(var->getType());
1366  } else if (isa<EnumConstantDecl>(value)) {
1367  CEK = CEK_AsValueOnly;
1368  } else {
1369  CEK = CEK_None;
1370  }
1371  if (CEK == CEK_None) return ConstantEmission();
1372 
1373  Expr::EvalResult result;
1374  bool resultIsReference;
1375  QualType resultType;
1376 
1377  // It's best to evaluate all the way as an r-value if that's permitted.
1378  if (CEK != CEK_AsReferenceOnly &&
1379  refExpr->EvaluateAsRValue(result, getContext())) {
1380  resultIsReference = false;
1381  resultType = refExpr->getType();
1382 
1383  // Otherwise, try to evaluate as an l-value.
1384  } else if (CEK != CEK_AsValueOnly &&
1385  refExpr->EvaluateAsLValue(result, getContext())) {
1386  resultIsReference = true;
1387  resultType = value->getType();
1388 
1389  // Failure.
1390  } else {
1391  return ConstantEmission();
1392  }
1393 
1394  // In any case, if the initializer has side-effects, abandon ship.
1395  if (result.HasSideEffects)
1396  return ConstantEmission();
1397 
1398  // Emit as a constant.
1399  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1400  result.Val, resultType);
1401 
1402  // Make sure we emit a debug reference to the global variable.
1403  // This should probably fire even for
1404  if (isa<VarDecl>(value)) {
1405  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1406  EmitDeclRefExprDbgValue(refExpr, result.Val);
1407  } else {
1408  assert(isa<EnumConstantDecl>(value));
1409  EmitDeclRefExprDbgValue(refExpr, result.Val);
1410  }
1411 
1412  // If we emitted a reference constant, we need to dereference that.
1413  if (resultIsReference)
1415 
1416  return ConstantEmission::forValue(C);
1417 }
1418 
1420  const MemberExpr *ME) {
1421  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1422  // Try to emit static variable member expressions as DREs.
1423  return DeclRefExpr::Create(
1425  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1426  ME->getType(), ME->getValueKind());
1427  }
1428  return nullptr;
1429 }
1430 
1433  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1434  return tryEmitAsConstant(DRE);
1435  return ConstantEmission();
1436 }
1437 
1439  SourceLocation Loc) {
1440  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1441  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1442  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1443 }
1444 
1446  if (Ty->isBooleanType())
1447  return true;
1448 
1449  if (const EnumType *ET = Ty->getAs<EnumType>())
1450  return ET->getDecl()->getIntegerType()->isBooleanType();
1451 
1452  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1453  return hasBooleanRepresentation(AT->getValueType());
1454 
1455  return false;
1456 }
1457 
1459  llvm::APInt &Min, llvm::APInt &End,
1460  bool StrictEnums, bool IsBool) {
1461  const EnumType *ET = Ty->getAs<EnumType>();
1462  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1463  ET && !ET->getDecl()->isFixed();
1464  if (!IsBool && !IsRegularCPlusPlusEnum)
1465  return false;
1466 
1467  if (IsBool) {
1468  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1469  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1470  } else {
1471  const EnumDecl *ED = ET->getDecl();
1472  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1473  unsigned Bitwidth = LTy->getScalarSizeInBits();
1474  unsigned NumNegativeBits = ED->getNumNegativeBits();
1475  unsigned NumPositiveBits = ED->getNumPositiveBits();
1476 
1477  if (NumNegativeBits) {
1478  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1479  assert(NumBits <= Bitwidth);
1480  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1481  Min = -End;
1482  } else {
1483  assert(NumPositiveBits <= Bitwidth);
1484  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1485  Min = llvm::APInt(Bitwidth, 0);
1486  }
1487  }
1488  return true;
1489 }
1490 
1491 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1492  llvm::APInt Min, End;
1493  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1495  return nullptr;
1496 
1497  llvm::MDBuilder MDHelper(getLLVMContext());
1498  return MDHelper.createRange(Min, End);
1499 }
1500 
1502  SourceLocation Loc) {
1503  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1504  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1505  if (!HasBoolCheck && !HasEnumCheck)
1506  return false;
1507 
1508  bool IsBool = hasBooleanRepresentation(Ty) ||
1509  NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1510  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1511  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1512  if (!NeedsBoolCheck && !NeedsEnumCheck)
1513  return false;
1514 
1515  // Single-bit booleans don't need to be checked. Special-case this to avoid
1516  // a bit width mismatch when handling bitfield values. This is handled by
1517  // EmitFromMemory for the non-bitfield case.
1518  if (IsBool &&
1519  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1520  return false;
1521 
1522  llvm::APInt Min, End;
1523  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1524  return true;
1525 
1526  auto &Ctx = getLLVMContext();
1527  SanitizerScope SanScope(this);
1528  llvm::Value *Check;
1529  --End;
1530  if (!Min) {
1531  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1532  } else {
1533  llvm::Value *Upper =
1534  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1535  llvm::Value *Lower =
1536  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1537  Check = Builder.CreateAnd(Upper, Lower);
1538  }
1539  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1542  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1543  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1544  StaticArgs, EmitCheckValue(Value));
1545  return true;
1546 }
1547 
1549  QualType Ty,
1550  SourceLocation Loc,
1551  LValueBaseInfo BaseInfo,
1552  TBAAAccessInfo TBAAInfo,
1553  bool isNontemporal) {
1554  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1555  // For better performance, handle vector loads differently.
1556  if (Ty->isVectorType()) {
1557  const llvm::Type *EltTy = Addr.getElementType();
1558 
1559  const auto *VTy = cast<llvm::VectorType>(EltTy);
1560 
1561  // Handle vectors of size 3 like size 4 for better performance.
1562  if (VTy->getNumElements() == 3) {
1563 
1564  // Bitcast to vec4 type.
1565  llvm::VectorType *vec4Ty =
1566  llvm::VectorType::get(VTy->getElementType(), 4);
1567  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1568  // Now load value.
1569  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1570 
1571  // Shuffle vector to get vec3.
1572  V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1573  {0, 1, 2}, "extractVec");
1574  return EmitFromMemory(V, Ty);
1575  }
1576  }
1577  }
1578 
1579  // Atomic operations have to be done on integral types.
1580  LValue AtomicLValue =
1581  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1582  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1583  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1584  }
1585 
1586  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1587  if (isNontemporal) {
1588  llvm::MDNode *Node = llvm::MDNode::get(
1589  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1590  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1591  }
1592 
1593  CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1594 
1595  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1596  // In order to prevent the optimizer from throwing away the check, don't
1597  // attach range metadata to the load.
1598  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1599  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1600  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1601 
1602  return EmitFromMemory(Load, Ty);
1603 }
1604 
1606  // Bool has a different representation in memory than in registers.
1607  if (hasBooleanRepresentation(Ty)) {
1608  // This should really always be an i1, but sometimes it's already
1609  // an i8, and it's awkward to track those cases down.
1610  if (Value->getType()->isIntegerTy(1))
1611  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1612  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1613  "wrong value rep of bool");
1614  }
1615 
1616  return Value;
1617 }
1618 
1620  // Bool has a different representation in memory than in registers.
1621  if (hasBooleanRepresentation(Ty)) {
1622  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1623  "wrong value rep of bool");
1624  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1625  }
1626 
1627  return Value;
1628 }
1629 
1631  bool Volatile, QualType Ty,
1632  LValueBaseInfo BaseInfo,
1633  TBAAAccessInfo TBAAInfo,
1634  bool isInit, bool isNontemporal) {
1635  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1636  // Handle vectors differently to get better performance.
1637  if (Ty->isVectorType()) {
1638  llvm::Type *SrcTy = Value->getType();
1639  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1640  // Handle vec3 special.
1641  if (VecTy && VecTy->getNumElements() == 3) {
1642  // Our source is a vec3, do a shuffle vector to make it a vec4.
1643  llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1644  Builder.getInt32(2),
1645  llvm::UndefValue::get(Builder.getInt32Ty())};
1646  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1647  Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1648  MaskV, "extractVec");
1649  SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1650  }
1651  if (Addr.getElementType() != SrcTy) {
1652  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1653  }
1654  }
1655  }
1656 
1657  Value = EmitToMemory(Value, Ty);
1658 
1659  LValue AtomicLValue =
1660  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1661  if (Ty->isAtomicType() ||
1662  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1663  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1664  return;
1665  }
1666 
1667  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1668  if (isNontemporal) {
1669  llvm::MDNode *Node =
1670  llvm::MDNode::get(Store->getContext(),
1671  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1672  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1673  }
1674 
1675  CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1676 }
1677 
1679  bool isInit) {
1680  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1681  lvalue.getType(), lvalue.getBaseInfo(),
1682  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1683 }
1684 
1685 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1686 /// method emits the address of the lvalue, then loads the result as an rvalue,
1687 /// returning the rvalue.
1689  if (LV.isObjCWeak()) {
1690  // load of a __weak object.
1691  Address AddrWeakObj = LV.getAddress();
1693  AddrWeakObj));
1694  }
1696  // In MRC mode, we do a load+autorelease.
1697  if (!getLangOpts().ObjCAutoRefCount) {
1698  return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1699  }
1700 
1701  // In ARC mode, we load retained and then consume the value.
1703  Object = EmitObjCConsumeObject(LV.getType(), Object);
1704  return RValue::get(Object);
1705  }
1706 
1707  if (LV.isSimple()) {
1708  assert(!LV.getType()->isFunctionType());
1709 
1710  // Everything needs a load.
1711  return RValue::get(EmitLoadOfScalar(LV, Loc));
1712  }
1713 
1714  if (LV.isVectorElt()) {
1715  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1716  LV.isVolatileQualified());
1717  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1718  "vecext"));
1719  }
1720 
1721  // If this is a reference to a subset of the elements of a vector, either
1722  // shuffle the input or extract/insert them as appropriate.
1723  if (LV.isExtVectorElt())
1725 
1726  // Global Register variables always invoke intrinsics
1727  if (LV.isGlobalReg())
1728  return EmitLoadOfGlobalRegLValue(LV);
1729 
1730  assert(LV.isBitField() && "Unknown LValue type!");
1731  return EmitLoadOfBitfieldLValue(LV, Loc);
1732 }
1733 
1735  SourceLocation Loc) {
1736  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1737 
1738  // Get the output type.
1739  llvm::Type *ResLTy = ConvertType(LV.getType());
1740 
1741  Address Ptr = LV.getBitFieldAddress();
1742  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1743 
1744  if (Info.IsSigned) {
1745  assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1746  unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1747  if (HighBits)
1748  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1749  if (Info.Offset + HighBits)
1750  Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1751  } else {
1752  if (Info.Offset)
1753  Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1754  if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1755  Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1756  Info.Size),
1757  "bf.clear");
1758  }
1759  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1760  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1761  return RValue::get(Val);
1762 }
1763 
1764 // If this is a reference to a subset of the elements of a vector, create an
1765 // appropriate shufflevector.
1768  LV.isVolatileQualified());
1769 
1770  const llvm::Constant *Elts = LV.getExtVectorElts();
1771 
1772  // If the result of the expression is a non-vector type, we must be extracting
1773  // a single element. Just codegen as an extractelement.
1774  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1775  if (!ExprVT) {
1776  unsigned InIdx = getAccessedFieldNo(0, Elts);
1777  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1778  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1779  }
1780 
1781  // Always use shuffle vector to try to retain the original program structure
1782  unsigned NumResultElts = ExprVT->getNumElements();
1783 
1785  for (unsigned i = 0; i != NumResultElts; ++i)
1786  Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1787 
1788  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1789  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1790  MaskV);
1791  return RValue::get(Vec);
1792 }
1793 
1794 /// @brief Generates lvalue for partial ext_vector access.
1796  Address VectorAddress = LV.getExtVectorAddress();
1797  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1798  QualType EQT = ExprVT->getElementType();
1799  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1800 
1801  Address CastToPointerElement =
1802  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1803  "conv.ptr.element");
1804 
1805  const llvm::Constant *Elts = LV.getExtVectorElts();
1806  unsigned ix = getAccessedFieldNo(0, Elts);
1807 
1808  Address VectorBasePtrPlusIx =
1809  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1810  getContext().getTypeSizeInChars(EQT),
1811  "vector.elt");
1812 
1813  return VectorBasePtrPlusIx;
1814 }
1815 
1816 /// @brief Load of global gamed gegisters are always calls to intrinsics.
1818  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1819  "Bad type for register variable");
1820  llvm::MDNode *RegName = cast<llvm::MDNode>(
1821  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1822 
1823  // We accept integer and pointer types only
1824  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1825  llvm::Type *Ty = OrigTy;
1826  if (OrigTy->isPointerTy())
1827  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1828  llvm::Type *Types[] = { Ty };
1829 
1830  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1831  llvm::Value *Call = Builder.CreateCall(
1832  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1833  if (OrigTy->isPointerTy())
1834  Call = Builder.CreateIntToPtr(Call, OrigTy);
1835  return RValue::get(Call);
1836 }
1837 
1838 
1839 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1840 /// lvalue, where both are guaranteed to the have the same type, and that type
1841 /// is 'Ty'.
1843  bool isInit) {
1844  if (!Dst.isSimple()) {
1845  if (Dst.isVectorElt()) {
1846  // Read/modify/write the vector, inserting the new element.
1848  Dst.isVolatileQualified());
1849  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1850  Dst.getVectorIdx(), "vecins");
1852  Dst.isVolatileQualified());
1853  return;
1854  }
1855 
1856  // If this is an update of extended vector elements, insert them as
1857  // appropriate.
1858  if (Dst.isExtVectorElt())
1860 
1861  if (Dst.isGlobalReg())
1862  return EmitStoreThroughGlobalRegLValue(Src, Dst);
1863 
1864  assert(Dst.isBitField() && "Unknown LValue type");
1865  return EmitStoreThroughBitfieldLValue(Src, Dst);
1866  }
1867 
1868  // There's special magic for assigning into an ARC-qualified l-value.
1869  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1870  switch (Lifetime) {
1871  case Qualifiers::OCL_None:
1872  llvm_unreachable("present but none");
1873 
1875  // nothing special
1876  break;
1877 
1879  if (isInit) {
1880  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1881  break;
1882  }
1883  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1884  return;
1885 
1886  case Qualifiers::OCL_Weak:
1887  if (isInit)
1888  // Initialize and then skip the primitive store.
1889  EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1890  else
1891  EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1892  return;
1893 
1896  Src.getScalarVal()));
1897  // fall into the normal path
1898  break;
1899  }
1900  }
1901 
1902  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1903  // load of a __weak object.
1904  Address LvalueDst = Dst.getAddress();
1905  llvm::Value *src = Src.getScalarVal();
1906  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1907  return;
1908  }
1909 
1910  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1911  // load of a __strong object.
1912  Address LvalueDst = Dst.getAddress();
1913  llvm::Value *src = Src.getScalarVal();
1914  if (Dst.isObjCIvar()) {
1915  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1916  llvm::Type *ResultType = IntPtrTy;
1918  llvm::Value *RHS = dst.getPointer();
1919  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1920  llvm::Value *LHS =
1921  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1922  "sub.ptr.lhs.cast");
1923  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1924  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1925  BytesBetween);
1926  } else if (Dst.isGlobalObjCRef()) {
1927  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1928  Dst.isThreadLocalRef());
1929  }
1930  else
1931  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1932  return;
1933  }
1934 
1935  assert(Src.isScalar() && "Can't emit an agg store with this method");
1936  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1937 }
1938 
1940  llvm::Value **Result) {
1941  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1942  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1943  Address Ptr = Dst.getBitFieldAddress();
1944 
1945  // Get the source value, truncated to the width of the bit-field.
1946  llvm::Value *SrcVal = Src.getScalarVal();
1947 
1948  // Cast the source to the storage type and shift it into place.
1949  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1950  /*IsSigned=*/false);
1951  llvm::Value *MaskedVal = SrcVal;
1952 
1953  // See if there are other bits in the bitfield's storage we'll need to load
1954  // and mask together with source before storing.
1955  if (Info.StorageSize != Info.Size) {
1956  assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1957  llvm::Value *Val =
1958  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1959 
1960  // Mask the source value as needed.
1961  if (!hasBooleanRepresentation(Dst.getType()))
1962  SrcVal = Builder.CreateAnd(SrcVal,
1963  llvm::APInt::getLowBitsSet(Info.StorageSize,
1964  Info.Size),
1965  "bf.value");
1966  MaskedVal = SrcVal;
1967  if (Info.Offset)
1968  SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1969 
1970  // Mask out the original value.
1971  Val = Builder.CreateAnd(Val,
1972  ~llvm::APInt::getBitsSet(Info.StorageSize,
1973  Info.Offset,
1974  Info.Offset + Info.Size),
1975  "bf.clear");
1976 
1977  // Or together the unchanged values and the source value.
1978  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
1979  } else {
1980  assert(Info.Offset == 0);
1981  }
1982 
1983  // Write the new value back out.
1984  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
1985 
1986  // Return the new value of the bit-field, if requested.
1987  if (Result) {
1988  llvm::Value *ResultVal = MaskedVal;
1989 
1990  // Sign extend the value if needed.
1991  if (Info.IsSigned) {
1992  assert(Info.Size <= Info.StorageSize);
1993  unsigned HighBits = Info.StorageSize - Info.Size;
1994  if (HighBits) {
1995  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
1996  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
1997  }
1998  }
1999 
2000  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2001  "bf.result.cast");
2002  *Result = EmitFromMemory(ResultVal, Dst.getType());
2003  }
2004 }
2005 
2007  LValue Dst) {
2008  // This access turns into a read/modify/write of the vector. Load the input
2009  // value now.
2011  Dst.isVolatileQualified());
2012  const llvm::Constant *Elts = Dst.getExtVectorElts();
2013 
2014  llvm::Value *SrcVal = Src.getScalarVal();
2015 
2016  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2017  unsigned NumSrcElts = VTy->getNumElements();
2018  unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2019  if (NumDstElts == NumSrcElts) {
2020  // Use shuffle vector is the src and destination are the same number of
2021  // elements and restore the vector mask since it is on the side it will be
2022  // stored.
2023  SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2024  for (unsigned i = 0; i != NumSrcElts; ++i)
2025  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2026 
2027  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2028  Vec = Builder.CreateShuffleVector(SrcVal,
2029  llvm::UndefValue::get(Vec->getType()),
2030  MaskV);
2031  } else if (NumDstElts > NumSrcElts) {
2032  // Extended the source vector to the same length and then shuffle it
2033  // into the destination.
2034  // FIXME: since we're shuffling with undef, can we just use the indices
2035  // into that? This could be simpler.
2037  for (unsigned i = 0; i != NumSrcElts; ++i)
2038  ExtMask.push_back(Builder.getInt32(i));
2039  ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2040  llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2041  llvm::Value *ExtSrcVal =
2042  Builder.CreateShuffleVector(SrcVal,
2043  llvm::UndefValue::get(SrcVal->getType()),
2044  ExtMaskV);
2045  // build identity
2047  for (unsigned i = 0; i != NumDstElts; ++i)
2048  Mask.push_back(Builder.getInt32(i));
2049 
2050  // When the vector size is odd and .odd or .hi is used, the last element
2051  // of the Elts constant array will be one past the size of the vector.
2052  // Ignore the last element here, if it is greater than the mask size.
2053  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2054  NumSrcElts--;
2055 
2056  // modify when what gets shuffled in
2057  for (unsigned i = 0; i != NumSrcElts; ++i)
2058  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2059  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2060  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2061  } else {
2062  // We should never shorten the vector
2063  llvm_unreachable("unexpected shorten vector length");
2064  }
2065  } else {
2066  // If the Src is a scalar (not a vector) it must be updating one element.
2067  unsigned InIdx = getAccessedFieldNo(0, Elts);
2068  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2069  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2070  }
2071 
2073  Dst.isVolatileQualified());
2074 }
2075 
2076 /// @brief Store of global named registers are always calls to intrinsics.
2078  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2079  "Bad type for register variable");
2080  llvm::MDNode *RegName = cast<llvm::MDNode>(
2081  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2082  assert(RegName && "Register LValue is not metadata");
2083 
2084  // We accept integer and pointer types only
2085  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2086  llvm::Type *Ty = OrigTy;
2087  if (OrigTy->isPointerTy())
2088  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2089  llvm::Type *Types[] = { Ty };
2090 
2091  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2092  llvm::Value *Value = Src.getScalarVal();
2093  if (OrigTy->isPointerTy())
2094  Value = Builder.CreatePtrToInt(Value, Ty);
2095  Builder.CreateCall(
2096  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2097 }
2098 
2099 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2100 // generating write-barries API. It is currently a global, ivar,
2101 // or neither.
2102 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2103  LValue &LV,
2104  bool IsMemberAccess=false) {
2105  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2106  return;
2107 
2108  if (isa<ObjCIvarRefExpr>(E)) {
2109  QualType ExpTy = E->getType();
2110  if (IsMemberAccess && ExpTy->isPointerType()) {
2111  // If ivar is a structure pointer, assigning to field of
2112  // this struct follows gcc's behavior and makes it a non-ivar
2113  // writer-barrier conservatively.
2114  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2115  if (ExpTy->isRecordType()) {
2116  LV.setObjCIvar(false);
2117  return;
2118  }
2119  }
2120  LV.setObjCIvar(true);
2121  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2122  LV.setBaseIvarExp(Exp->getBase());
2123  LV.setObjCArray(E->getType()->isArrayType());
2124  return;
2125  }
2126 
2127  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2128  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2129  if (VD->hasGlobalStorage()) {
2130  LV.setGlobalObjCRef(true);
2131  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2132  }
2133  }
2134  LV.setObjCArray(E->getType()->isArrayType());
2135  return;
2136  }
2137 
2138  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2139  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2140  return;
2141  }
2142 
2143  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2144  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2145  if (LV.isObjCIvar()) {
2146  // If cast is to a structure pointer, follow gcc's behavior and make it
2147  // a non-ivar write-barrier.
2148  QualType ExpTy = E->getType();
2149  if (ExpTy->isPointerType())
2150  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2151  if (ExpTy->isRecordType())
2152  LV.setObjCIvar(false);
2153  }
2154  return;
2155  }
2156 
2157  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2158  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2159  return;
2160  }
2161 
2162  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2163  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2164  return;
2165  }
2166 
2167  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2168  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2169  return;
2170  }
2171 
2172  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2173  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2174  return;
2175  }
2176 
2177  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2178  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2179  if (LV.isObjCIvar() && !LV.isObjCArray())
2180  // Using array syntax to assigning to what an ivar points to is not
2181  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2182  LV.setObjCIvar(false);
2183  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2184  // Using array syntax to assigning to what global points to is not
2185  // same as assigning to the global itself. {id *G;} G[i] = 0;
2186  LV.setGlobalObjCRef(false);
2187  return;
2188  }
2189 
2190  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2191  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2192  // We don't know if member is an 'ivar', but this flag is looked at
2193  // only in the context of LV.isObjCIvar().
2194  LV.setObjCArray(E->getType()->isArrayType());
2195  return;
2196  }
2197 }
2198 
2199 static llvm::Value *
2201  llvm::Value *V, llvm::Type *IRType,
2202  StringRef Name = StringRef()) {
2203  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2204  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2205 }
2206 
2208  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2209  llvm::Type *RealVarTy, SourceLocation Loc) {
2210  Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2211  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2212  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2213 }
2214 
2216  const VarDecl *VD, QualType T) {
2217  for (const auto *D : VD->redecls()) {
2218  if (!VD->hasAttrs())
2219  continue;
2220  if (const auto *Attr = D->getAttr<OMPDeclareTargetDeclAttr>())
2221  if (Attr->getMapType() == OMPDeclareTargetDeclAttr::MT_Link) {
2222  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2223  Address Addr =
2224  CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
2225  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2226  }
2227  }
2228  return Address::invalid();
2229 }
2230 
2231 Address
2233  LValueBaseInfo *PointeeBaseInfo,
2234  TBAAAccessInfo *PointeeTBAAInfo) {
2235  llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2236  RefLVal.isVolatile());
2237  CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2238 
2240  PointeeBaseInfo, PointeeTBAAInfo,
2241  /* forPointeeType= */ true);
2242  return Address(Load, Align);
2243 }
2244 
2246  LValueBaseInfo PointeeBaseInfo;
2247  TBAAAccessInfo PointeeTBAAInfo;
2248  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2249  &PointeeTBAAInfo);
2250  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2251  PointeeBaseInfo, PointeeTBAAInfo);
2252 }
2253 
2255  const PointerType *PtrTy,
2256  LValueBaseInfo *BaseInfo,
2257  TBAAAccessInfo *TBAAInfo) {
2258  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2259  return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2260  BaseInfo, TBAAInfo,
2261  /*forPointeeType=*/true));
2262 }
2263 
2265  const PointerType *PtrTy) {
2266  LValueBaseInfo BaseInfo;
2267  TBAAAccessInfo TBAAInfo;
2268  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2269  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2270 }
2271 
2273  const Expr *E, const VarDecl *VD) {
2274  QualType T = E->getType();
2275 
2276  // If it's thread_local, emit a call to its wrapper function instead.
2277  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2279  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2280  // Check if the variable is marked as declare target with link clause in
2281  // device codegen.
2282  if (CGF.getLangOpts().OpenMPIsDevice) {
2283  Address Addr = emitDeclTargetLinkVarDeclLValue(CGF, VD, T);
2284  if (Addr.isValid())
2285  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2286  }
2287 
2288  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2289  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2290  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2291  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2292  Address Addr(V, Alignment);
2293  // Emit reference to the private copy of the variable if it is an OpenMP
2294  // threadprivate variable.
2295  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2296  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2297  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2298  E->getExprLoc());
2299  }
2300  LValue LV = VD->getType()->isReferenceType() ?
2301  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2303  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2304  setObjCGCLValueClass(CGF.getContext(), E, LV);
2305  return LV;
2306 }
2307 
2309  const FunctionDecl *FD) {
2310  if (FD->hasAttr<WeakRefAttr>()) {
2311  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2312  return aliasee.getPointer();
2313  }
2314 
2315  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2316  if (!FD->hasPrototype()) {
2317  if (const FunctionProtoType *Proto =
2318  FD->getType()->getAs<FunctionProtoType>()) {
2319  // Ugly case: for a K&R-style definition, the type of the definition
2320  // isn't the same as the type of a use. Correct for this with a
2321  // bitcast.
2322  QualType NoProtoType =
2323  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2324  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2325  V = llvm::ConstantExpr::getBitCast(V,
2326  CGM.getTypes().ConvertType(NoProtoType));
2327  }
2328  }
2329  return V;
2330 }
2331 
2333  const Expr *E, const FunctionDecl *FD) {
2334  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2335  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2336  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2338 }
2339 
2341  llvm::Value *ThisValue) {
2343  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2344  return CGF.EmitLValueForField(LV, FD);
2345 }
2346 
2347 /// Named Registers are named metadata pointing to the register name
2348 /// which will be read from/written to as an argument to the intrinsic
2349 /// @llvm.read/write_register.
2350 /// So far, only the name is being passed down, but other options such as
2351 /// register type, allocation type or even optimization options could be
2352 /// passed down via the metadata node.
2354  SmallString<64> Name("llvm.named.register.");
2355  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2356  assert(Asm->getLabel().size() < 64-Name.size() &&
2357  "Register name too big");
2358  Name.append(Asm->getLabel());
2359  llvm::NamedMDNode *M =
2360  CGM.getModule().getOrInsertNamedMetadata(Name);
2361  if (M->getNumOperands() == 0) {
2362  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2363  Asm->getLabel());
2364  llvm::Metadata *Ops[] = {Str};
2365  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2366  }
2367 
2368  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2369 
2370  llvm::Value *Ptr =
2371  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2372  return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2373 }
2374 
2376  const NamedDecl *ND = E->getDecl();
2377  QualType T = E->getType();
2378 
2379  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2380  // Global Named registers access via intrinsics only
2381  if (VD->getStorageClass() == SC_Register &&
2382  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2383  return EmitGlobalNamedRegister(VD, CGM);
2384 
2385  // A DeclRefExpr for a reference initialized by a constant expression can
2386  // appear without being odr-used. Directly emit the constant initializer.
2387  const Expr *Init = VD->getAnyInitializer(VD);
2388  if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2389  VD->isUsableInConstantExpressions(getContext()) &&
2390  VD->checkInitIsICE() &&
2391  // Do not emit if it is private OpenMP variable.
2393  ((CapturedStmtInfo &&
2394  (LocalDeclMap.count(VD->getCanonicalDecl()) ||
2395  CapturedStmtInfo->lookup(VD->getCanonicalDecl()))) ||
2396  LambdaCaptureFields.lookup(VD->getCanonicalDecl()) ||
2397  isa<BlockDecl>(CurCodeDecl)))) {
2398  llvm::Constant *Val =
2400  *VD->evaluateValue(),
2401  VD->getType());
2402  assert(Val && "failed to emit reference constant expression");
2403  // FIXME: Eventually we will want to emit vector element references.
2404 
2405  // Should we be using the alignment of the constant pointer we emitted?
2406  CharUnits Alignment = getNaturalTypeAlignment(E->getType(),
2407  /* BaseInfo= */ nullptr,
2408  /* TBAAInfo= */ nullptr,
2409  /* forPointeeType= */ true);
2410  return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2411  }
2412 
2413  // Check for captured variables.
2415  VD = VD->getCanonicalDecl();
2416  if (auto *FD = LambdaCaptureFields.lookup(VD))
2417  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2418  else if (CapturedStmtInfo) {
2419  auto I = LocalDeclMap.find(VD);
2420  if (I != LocalDeclMap.end()) {
2421  if (VD->getType()->isReferenceType())
2422  return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2424  return MakeAddrLValue(I->second, T);
2425  }
2426  LValue CapLVal =
2429  return MakeAddrLValue(
2430  Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2432  CapLVal.getTBAAInfo());
2433  }
2434 
2435  assert(isa<BlockDecl>(CurCodeDecl));
2436  Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2437  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2438  }
2439  }
2440 
2441  // FIXME: We should be able to assert this for FunctionDecls as well!
2442  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2443  // those with a valid source location.
2444  assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2445  !E->getLocation().isValid()) &&
2446  "Should not use decl without marking it used!");
2447 
2448  if (ND->hasAttr<WeakRefAttr>()) {
2449  const auto *VD = cast<ValueDecl>(ND);
2450  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2451  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2452  }
2453 
2454  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2455  // Check if this is a global variable.
2456  if (VD->hasLinkage() || VD->isStaticDataMember())
2457  return EmitGlobalVarDeclLValue(*this, E, VD);
2458 
2459  Address addr = Address::invalid();
2460 
2461  // The variable should generally be present in the local decl map.
2462  auto iter = LocalDeclMap.find(VD);
2463  if (iter != LocalDeclMap.end()) {
2464  addr = iter->second;
2465 
2466  // Otherwise, it might be static local we haven't emitted yet for
2467  // some reason; most likely, because it's in an outer function.
2468  } else if (VD->isStaticLocal()) {
2470  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2471  getContext().getDeclAlign(VD));
2472 
2473  // No other cases for now.
2474  } else {
2475  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2476  }
2477 
2478 
2479  // Check for OpenMP threadprivate variables.
2480  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2481  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2483  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2484  E->getExprLoc());
2485  }
2486 
2487  // Drill into block byref variables.
2488  bool isBlockByref = VD->hasAttr<BlocksAttr>();
2489  if (isBlockByref) {
2490  addr = emitBlockByrefAddress(addr, VD);
2491  }
2492 
2493  // Drill into reference types.
2494  LValue LV = VD->getType()->isReferenceType() ?
2497 
2498  bool isLocalStorage = VD->hasLocalStorage();
2499 
2500  bool NonGCable = isLocalStorage &&
2501  !VD->getType()->isReferenceType() &&
2502  !isBlockByref;
2503  if (NonGCable) {
2504  LV.getQuals().removeObjCGCAttr();
2505  LV.setNonGC(true);
2506  }
2507 
2508  bool isImpreciseLifetime =
2509  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2510  if (isImpreciseLifetime)
2512  setObjCGCLValueClass(getContext(), E, LV);
2513  return LV;
2514  }
2515 
2516  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2517  return EmitFunctionDeclLValue(*this, E, FD);
2518 
2519  // FIXME: While we're emitting a binding from an enclosing scope, all other
2520  // DeclRefExprs we see should be implicitly treated as if they also refer to
2521  // an enclosing scope.
2522  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2523  return EmitLValue(BD->getBinding());
2524 
2525  llvm_unreachable("Unhandled DeclRefExpr");
2526 }
2527 
2529  // __extension__ doesn't affect lvalue-ness.
2530  if (E->getOpcode() == UO_Extension)
2531  return EmitLValue(E->getSubExpr());
2532 
2534  switch (E->getOpcode()) {
2535  default: llvm_unreachable("Unknown unary operator lvalue!");
2536  case UO_Deref: {
2538  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2539 
2540  LValueBaseInfo BaseInfo;
2541  TBAAAccessInfo TBAAInfo;
2542  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2543  &TBAAInfo);
2544  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2545  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2546 
2547  // We should not generate __weak write barrier on indirect reference
2548  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2549  // But, we continue to generate __strong write barrier on indirect write
2550  // into a pointer to object.
2551  if (getLangOpts().ObjC1 &&
2552  getLangOpts().getGC() != LangOptions::NonGC &&
2553  LV.isObjCWeak())
2554  LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2555  return LV;
2556  }
2557  case UO_Real:
2558  case UO_Imag: {
2559  LValue LV = EmitLValue(E->getSubExpr());
2560  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2561 
2562  // __real is valid on scalars. This is a faster way of testing that.
2563  // __imag can only produce an rvalue on scalars.
2564  if (E->getOpcode() == UO_Real &&
2565  !LV.getAddress().getElementType()->isStructTy()) {
2566  assert(E->getSubExpr()->getType()->isArithmeticType());
2567  return LV;
2568  }
2569 
2570  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2571 
2572  Address Component =
2573  (E->getOpcode() == UO_Real
2576  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2577  CGM.getTBAAInfoForSubobject(LV, T));
2578  ElemLV.getQuals().addQualifiers(LV.getQuals());
2579  return ElemLV;
2580  }
2581  case UO_PreInc:
2582  case UO_PreDec: {
2583  LValue LV = EmitLValue(E->getSubExpr());
2584  bool isInc = E->getOpcode() == UO_PreInc;
2585 
2586  if (E->getType()->isAnyComplexType())
2587  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2588  else
2589  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2590  return LV;
2591  }
2592  }
2593 }
2594 
2598 }
2599 
2603 }
2604 
2606  auto SL = E->getFunctionName();
2607  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2608  StringRef FnName = CurFn->getName();
2609  if (FnName.startswith("\01"))
2610  FnName = FnName.substr(1);
2611  StringRef NameItems[] = {
2613  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2614  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2615  std::string Name = SL->getString();
2616  if (!Name.empty()) {
2617  unsigned Discriminator =
2618  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2619  if (Discriminator)
2620  Name += "_" + Twine(Discriminator + 1).str();
2621  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2622  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2623  } else {
2624  auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2625  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2626  }
2627  }
2628  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2629  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2630 }
2631 
2632 /// Emit a type description suitable for use by a runtime sanitizer library. The
2633 /// format of a type descriptor is
2634 ///
2635 /// \code
2636 /// { i16 TypeKind, i16 TypeInfo }
2637 /// \endcode
2638 ///
2639 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2640 /// integer, 1 for a floating point value, and -1 for anything else.
2642  // Only emit each type's descriptor once.
2643  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2644  return C;
2645 
2646  uint16_t TypeKind = -1;
2647  uint16_t TypeInfo = 0;
2648 
2649  if (T->isIntegerType()) {
2650  TypeKind = 0;
2651  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2652  (T->isSignedIntegerType() ? 1 : 0);
2653  } else if (T->isFloatingType()) {
2654  TypeKind = 1;
2655  TypeInfo = getContext().getTypeSize(T);
2656  }
2657 
2658  // Format the type name as if for a diagnostic, including quotes and
2659  // optionally an 'aka'.
2660  SmallString<32> Buffer;
2662  (intptr_t)T.getAsOpaquePtr(),
2663  StringRef(), StringRef(), None, Buffer,
2664  None);
2665 
2666  llvm::Constant *Components[] = {
2667  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2668  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2669  };
2670  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2671 
2672  auto *GV = new llvm::GlobalVariable(
2673  CGM.getModule(), Descriptor->getType(),
2674  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2675  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2677 
2678  // Remember the descriptor for this type.
2679  CGM.setTypeDescriptorInMap(T, GV);
2680 
2681  return GV;
2682 }
2683 
2685  llvm::Type *TargetTy = IntPtrTy;
2686 
2687  if (V->getType() == TargetTy)
2688  return V;
2689 
2690  // Floating-point types which fit into intptr_t are bitcast to integers
2691  // and then passed directly (after zero-extension, if necessary).
2692  if (V->getType()->isFloatingPointTy()) {
2693  unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2694  if (Bits <= TargetTy->getIntegerBitWidth())
2695  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2696  Bits));
2697  }
2698 
2699  // Integers which fit in intptr_t are zero-extended and passed directly.
2700  if (V->getType()->isIntegerTy() &&
2701  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2702  return Builder.CreateZExt(V, TargetTy);
2703 
2704  // Pointers are passed directly, everything else is passed by address.
2705  if (!V->getType()->isPointerTy()) {
2706  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2707  Builder.CreateStore(V, Ptr);
2708  V = Ptr.getPointer();
2709  }
2710  return Builder.CreatePtrToInt(V, TargetTy);
2711 }
2712 
2713 /// \brief Emit a representation of a SourceLocation for passing to a handler
2714 /// in a sanitizer runtime library. The format for this data is:
2715 /// \code
2716 /// struct SourceLocation {
2717 /// const char *Filename;
2718 /// int32_t Line, Column;
2719 /// };
2720 /// \endcode
2721 /// For an invalid SourceLocation, the Filename pointer is null.
2723  llvm::Constant *Filename;
2724  int Line, Column;
2725 
2727  if (PLoc.isValid()) {
2728  StringRef FilenameString = PLoc.getFilename();
2729 
2730  int PathComponentsToStrip =
2731  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2732  if (PathComponentsToStrip < 0) {
2733  assert(PathComponentsToStrip != INT_MIN);
2734  int PathComponentsToKeep = -PathComponentsToStrip;
2735  auto I = llvm::sys::path::rbegin(FilenameString);
2736  auto E = llvm::sys::path::rend(FilenameString);
2737  while (I != E && --PathComponentsToKeep)
2738  ++I;
2739 
2740  FilenameString = FilenameString.substr(I - E);
2741  } else if (PathComponentsToStrip > 0) {
2742  auto I = llvm::sys::path::begin(FilenameString);
2743  auto E = llvm::sys::path::end(FilenameString);
2744  while (I != E && PathComponentsToStrip--)
2745  ++I;
2746 
2747  if (I != E)
2748  FilenameString =
2749  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2750  else
2751  FilenameString = llvm::sys::path::filename(FilenameString);
2752  }
2753 
2754  auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2756  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2757  Filename = FilenameGV.getPointer();
2758  Line = PLoc.getLine();
2759  Column = PLoc.getColumn();
2760  } else {
2761  Filename = llvm::Constant::getNullValue(Int8PtrTy);
2762  Line = Column = 0;
2763  }
2764 
2765  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2766  Builder.getInt32(Column)};
2767 
2768  return llvm::ConstantStruct::getAnon(Data);
2769 }
2770 
2771 namespace {
2772 /// \brief Specify under what conditions this check can be recovered
2774  /// Always terminate program execution if this check fails.
2775  Unrecoverable,
2776  /// Check supports recovering, runtime has both fatal (noreturn) and
2777  /// non-fatal handlers for this check.
2778  Recoverable,
2779  /// Runtime conditionally aborts, always need to support recovery.
2781 };
2782 }
2783 
2785  assert(llvm::countPopulation(Kind) == 1);
2786  switch (Kind) {
2787  case SanitizerKind::Vptr:
2789  case SanitizerKind::Return:
2790  case SanitizerKind::Unreachable:
2792  default:
2793  return CheckRecoverableKind::Recoverable;
2794  }
2795 }
2796 
2797 namespace {
2798 struct SanitizerHandlerInfo {
2799  char const *const Name;
2800  unsigned Version;
2801 };
2802 }
2803 
2804 const SanitizerHandlerInfo SanitizerHandlers[] = {
2805 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2807 #undef SANITIZER_CHECK
2808 };
2809 
2811  llvm::FunctionType *FnType,
2812  ArrayRef<llvm::Value *> FnArgs,
2813  SanitizerHandler CheckHandler,
2814  CheckRecoverableKind RecoverKind, bool IsFatal,
2815  llvm::BasicBlock *ContBB) {
2816  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2817  bool NeedsAbortSuffix =
2818  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2819  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2820  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2821  const StringRef CheckName = CheckInfo.Name;
2822  std::string FnName = "__ubsan_handle_" + CheckName.str();
2823  if (CheckInfo.Version && !MinimalRuntime)
2824  FnName += "_v" + llvm::utostr(CheckInfo.Version);
2825  if (MinimalRuntime)
2826  FnName += "_minimal";
2827  if (NeedsAbortSuffix)
2828  FnName += "_abort";
2829  bool MayReturn =
2830  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2831 
2832  llvm::AttrBuilder B;
2833  if (!MayReturn) {
2834  B.addAttribute(llvm::Attribute::NoReturn)
2835  .addAttribute(llvm::Attribute::NoUnwind);
2836  }
2837  B.addAttribute(llvm::Attribute::UWTable);
2838 
2840  FnType, FnName,
2841  llvm::AttributeList::get(CGF.getLLVMContext(),
2842  llvm::AttributeList::FunctionIndex, B),
2843  /*Local=*/true);
2844  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2845  if (!MayReturn) {
2846  HandlerCall->setDoesNotReturn();
2847  CGF.Builder.CreateUnreachable();
2848  } else {
2849  CGF.Builder.CreateBr(ContBB);
2850  }
2851 }
2852 
2854  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2855  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2856  ArrayRef<llvm::Value *> DynamicArgs) {
2857  assert(IsSanitizerScope);
2858  assert(Checked.size() > 0);
2859  assert(CheckHandler >= 0 &&
2860  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
2861  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2862 
2863  llvm::Value *FatalCond = nullptr;
2864  llvm::Value *RecoverableCond = nullptr;
2865  llvm::Value *TrapCond = nullptr;
2866  for (int i = 0, n = Checked.size(); i < n; ++i) {
2867  llvm::Value *Check = Checked[i].first;
2868  // -fsanitize-trap= overrides -fsanitize-recover=.
2869  llvm::Value *&Cond =
2870  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2871  ? TrapCond
2872  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2873  ? RecoverableCond
2874  : FatalCond;
2875  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2876  }
2877 
2878  if (TrapCond)
2879  EmitTrapCheck(TrapCond);
2880  if (!FatalCond && !RecoverableCond)
2881  return;
2882 
2883  llvm::Value *JointCond;
2884  if (FatalCond && RecoverableCond)
2885  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2886  else
2887  JointCond = FatalCond ? FatalCond : RecoverableCond;
2888  assert(JointCond);
2889 
2890  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2891  assert(SanOpts.has(Checked[0].second));
2892 #ifndef NDEBUG
2893  for (int i = 1, n = Checked.size(); i < n; ++i) {
2894  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2895  "All recoverable kinds in a single check must be same!");
2896  assert(SanOpts.has(Checked[i].second));
2897  }
2898 #endif
2899 
2900  llvm::BasicBlock *Cont = createBasicBlock("cont");
2901  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2902  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2903  // Give hint that we very much don't expect to execute the handler
2904  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2905  llvm::MDBuilder MDHelper(getLLVMContext());
2906  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2907  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2908  EmitBlock(Handlers);
2909 
2910  // Handler functions take an i8* pointing to the (handler-specific) static
2911  // information block, followed by a sequence of intptr_t arguments
2912  // representing operand values.
2915  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
2916  Args.reserve(DynamicArgs.size() + 1);
2917  ArgTypes.reserve(DynamicArgs.size() + 1);
2918 
2919  // Emit handler arguments and create handler function type.
2920  if (!StaticArgs.empty()) {
2921  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2922  auto *InfoPtr =
2923  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2924  llvm::GlobalVariable::PrivateLinkage, Info);
2925  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2927  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2928  ArgTypes.push_back(Int8PtrTy);
2929  }
2930 
2931  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2932  Args.push_back(EmitCheckValue(DynamicArgs[i]));
2933  ArgTypes.push_back(IntPtrTy);
2934  }
2935  }
2936 
2937  llvm::FunctionType *FnType =
2938  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2939 
2940  if (!FatalCond || !RecoverableCond) {
2941  // Simple case: we need to generate a single handler call, either
2942  // fatal, or non-fatal.
2943  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
2944  (FatalCond != nullptr), Cont);
2945  } else {
2946  // Emit two handler calls: first one for set of unrecoverable checks,
2947  // another one for recoverable.
2948  llvm::BasicBlock *NonFatalHandlerBB =
2949  createBasicBlock("non_fatal." + CheckName);
2950  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2951  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2952  EmitBlock(FatalHandlerBB);
2953  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
2954  NonFatalHandlerBB);
2955  EmitBlock(NonFatalHandlerBB);
2956  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
2957  Cont);
2958  }
2959 
2960  EmitBlock(Cont);
2961 }
2962 
2964  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2965  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2966  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2967 
2968  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2969  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2970 
2971  llvm::MDBuilder MDHelper(getLLVMContext());
2972  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2973  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2974 
2975  EmitBlock(CheckBB);
2976 
2977  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
2978 
2979  llvm::CallInst *CheckCall;
2980  llvm::Constant *SlowPathFn;
2981  if (WithDiag) {
2982  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2983  auto *InfoPtr =
2984  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2985  llvm::GlobalVariable::PrivateLinkage, Info);
2986  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2988 
2989  SlowPathFn = CGM.getModule().getOrInsertFunction(
2990  "__cfi_slowpath_diag",
2991  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
2992  false));
2993  CheckCall = Builder.CreateCall(
2994  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
2995  } else {
2996  SlowPathFn = CGM.getModule().getOrInsertFunction(
2997  "__cfi_slowpath",
2998  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
2999  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3000  }
3001 
3002  CGM.setDSOLocal(cast<llvm::GlobalValue>(SlowPathFn->stripPointerCasts()));
3003  CheckCall->setDoesNotThrow();
3004 
3005  EmitBlock(Cont);
3006 }
3007 
3008 // Emit a stub for __cfi_check function so that the linker knows about this
3009 // symbol in LTO mode.
3011  llvm::Module *M = &CGM.getModule();
3012  auto &Ctx = M->getContext();
3013  llvm::Function *F = llvm::Function::Create(
3014  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3015  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3016  CGM.setDSOLocal(F);
3017  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3018  // FIXME: consider emitting an intrinsic call like
3019  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3020  // which can be lowered in CrossDSOCFI pass to the actual contents of
3021  // __cfi_check. This would allow inlining of __cfi_check calls.
3023  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3024  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3025 }
3026 
3027 // This function is basically a switch over the CFI failure kind, which is
3028 // extracted from CFICheckFailData (1st function argument). Each case is either
3029 // llvm.trap or a call to one of the two runtime handlers, based on
3030 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3031 // failure kind) traps, but this should really never happen. CFICheckFailData
3032 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3033 // check kind; in this case __cfi_check_fail traps as well.
3035  SanitizerScope SanScope(this);
3036  FunctionArgList Args;
3041  Args.push_back(&ArgData);
3042  Args.push_back(&ArgAddr);
3043 
3044  const CGFunctionInfo &FI =
3046 
3047  llvm::Function *F = llvm::Function::Create(
3048  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3049  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3050  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3051 
3052  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3053  SourceLocation());
3054 
3055  llvm::Value *Data =
3056  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3057  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3058  llvm::Value *Addr =
3059  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3060  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3061 
3062  // Data == nullptr means the calling module has trap behaviour for this check.
3063  llvm::Value *DataIsNotNullPtr =
3064  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3065  EmitTrapCheck(DataIsNotNullPtr);
3066 
3067  llvm::StructType *SourceLocationTy =
3068  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3069  llvm::StructType *CfiCheckFailDataTy =
3070  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3071 
3072  llvm::Value *V = Builder.CreateConstGEP2_32(
3073  CfiCheckFailDataTy,
3074  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3075  0);
3076  Address CheckKindAddr(V, getIntAlign());
3077  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3078 
3079  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3080  CGM.getLLVMContext(),
3081  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3082  llvm::Value *ValidVtable = Builder.CreateZExt(
3083  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3084  {Addr, AllVtables}),
3085  IntPtrTy);
3086 
3087  const std::pair<int, SanitizerMask> CheckKinds[] = {
3088  {CFITCK_VCall, SanitizerKind::CFIVCall},
3089  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3090  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3091  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3092  {CFITCK_ICall, SanitizerKind::CFIICall}};
3093 
3095  for (auto CheckKindMaskPair : CheckKinds) {
3096  int Kind = CheckKindMaskPair.first;
3097  SanitizerMask Mask = CheckKindMaskPair.second;
3098  llvm::Value *Cond =
3099  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3100  if (CGM.getLangOpts().Sanitize.has(Mask))
3101  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3102  {Data, Addr, ValidVtable});
3103  else
3104  EmitTrapCheck(Cond);
3105  }
3106 
3107  FinishFunction();
3108  // The only reference to this function will be created during LTO link.
3109  // Make sure it survives until then.
3110  CGM.addUsedGlobal(F);
3111 }
3112 
3114  if (SanOpts.has(SanitizerKind::Unreachable)) {
3115  SanitizerScope SanScope(this);
3116  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3117  SanitizerKind::Unreachable),
3118  SanitizerHandler::BuiltinUnreachable,
3119  EmitCheckSourceLocation(Loc), None);
3120  }
3121  Builder.CreateUnreachable();
3122 }
3123 
3125  llvm::BasicBlock *Cont = createBasicBlock("cont");
3126 
3127  // If we're optimizing, collapse all calls to trap down to just one per
3128  // function to save on code size.
3129  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3130  TrapBB = createBasicBlock("trap");
3131  Builder.CreateCondBr(Checked, Cont, TrapBB);
3132  EmitBlock(TrapBB);
3133  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3134  TrapCall->setDoesNotReturn();
3135  TrapCall->setDoesNotThrow();
3136  Builder.CreateUnreachable();
3137  } else {
3138  Builder.CreateCondBr(Checked, Cont, TrapBB);
3139  }
3140 
3141  EmitBlock(Cont);
3142 }
3143 
3145  llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3146 
3147  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3148  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3150  TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3151  }
3152 
3153  return TrapCall;
3154 }
3155 
3157  LValueBaseInfo *BaseInfo,
3158  TBAAAccessInfo *TBAAInfo) {
3159  assert(E->getType()->isArrayType() &&
3160  "Array to pointer decay must have array source type!");
3161 
3162  // Expressions of array type can't be bitfields or vector elements.
3163  LValue LV = EmitLValue(E);
3164  Address Addr = LV.getAddress();
3165 
3166  // If the array type was an incomplete type, we need to make sure
3167  // the decay ends up being the right type.
3168  llvm::Type *NewTy = ConvertType(E->getType());
3169  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3170 
3171  // Note that VLA pointers are always decayed, so we don't need to do
3172  // anything here.
3173  if (!E->getType()->isVariableArrayType()) {
3174  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3175  "Expected pointer to array");
3176  Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
3177  }
3178 
3179  // The result of this decay conversion points to an array element within the
3180  // base lvalue. However, since TBAA currently does not support representing
3181  // accesses to elements of member arrays, we conservatively represent accesses
3182  // to the pointee object as if it had no any base lvalue specified.
3183  // TODO: Support TBAA for member arrays.
3185  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3186  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3187 
3188  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3189 }
3190 
3191 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3192 /// array to pointer, return the array subexpression.
3193 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3194  // If this isn't just an array->pointer decay, bail out.
3195  const auto *CE = dyn_cast<CastExpr>(E);
3196  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3197  return nullptr;
3198 
3199  // If this is a decay from variable width array, bail out.
3200  const Expr *SubExpr = CE->getSubExpr();
3201  if (SubExpr->getType()->isVariableArrayType())
3202  return nullptr;
3203 
3204  return SubExpr;
3205 }
3206 
3208  llvm::Value *ptr,
3209  ArrayRef<llvm::Value*> indices,
3210  bool inbounds,
3211  bool signedIndices,
3212  SourceLocation loc,
3213  const llvm::Twine &name = "arrayidx") {
3214  if (inbounds) {
3215  return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3217  name);
3218  } else {
3219  return CGF.Builder.CreateGEP(ptr, indices, name);
3220  }
3221 }
3222 
3224  llvm::Value *idx,
3225  CharUnits eltSize) {
3226  // If we have a constant index, we can use the exact offset of the
3227  // element we're accessing.
3228  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3229  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3230  return arrayAlign.alignmentAtOffset(offset);
3231 
3232  // Otherwise, use the worst-case alignment for any element.
3233  } else {
3234  return arrayAlign.alignmentOfArrayElement(eltSize);
3235  }
3236 }
3237 
3239  const VariableArrayType *vla) {
3240  QualType eltType;
3241  do {
3242  eltType = vla->getElementType();
3243  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3244  return eltType;
3245 }
3246 
3248  ArrayRef<llvm::Value *> indices,
3249  QualType eltType, bool inbounds,
3250  bool signedIndices, SourceLocation loc,
3251  const llvm::Twine &name = "arrayidx") {
3252  // All the indices except that last must be zero.
3253 #ifndef NDEBUG
3254  for (auto idx : indices.drop_back())
3255  assert(isa<llvm::ConstantInt>(idx) &&
3256  cast<llvm::ConstantInt>(idx)->isZero());
3257 #endif
3258 
3259  // Determine the element size of the statically-sized base. This is
3260  // the thing that the indices are expressed in terms of.
3261  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3262  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3263  }
3264 
3265  // We can use that to compute the best alignment of the element.
3266  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3267  CharUnits eltAlign =
3268  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3269 
3271  CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
3272  return Address(eltPtr, eltAlign);
3273 }
3274 
3276  bool Accessed) {
3277  // The index must always be an integer, which is not an aggregate. Emit it
3278  // in lexical order (this complexity is, sadly, required by C++17).
3279  llvm::Value *IdxPre =
3280  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3281  bool SignedIndices = false;
3282  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3283  auto *Idx = IdxPre;
3284  if (E->getLHS() != E->getIdx()) {
3285  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3286  Idx = EmitScalarExpr(E->getIdx());
3287  }
3288 
3289  QualType IdxTy = E->getIdx()->getType();
3290  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3291  SignedIndices |= IdxSigned;
3292 
3293  if (SanOpts.has(SanitizerKind::ArrayBounds))
3294  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3295 
3296  // Extend or truncate the index type to 32 or 64-bits.
3297  if (Promote && Idx->getType() != IntPtrTy)
3298  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3299 
3300  return Idx;
3301  };
3302  IdxPre = nullptr;
3303 
3304  // If the base is a vector type, then we are forming a vector element lvalue
3305  // with this subscript.
3306  if (E->getBase()->getType()->isVectorType() &&
3307  !isa<ExtVectorElementExpr>(E->getBase())) {
3308  // Emit the vector as an lvalue to get its address.
3309  LValue LHS = EmitLValue(E->getBase());
3310  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3311  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3312  return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3313  LHS.getBaseInfo(), TBAAAccessInfo());
3314  }
3315 
3316  // All the other cases basically behave like simple offsetting.
3317 
3318  // Handle the extvector case we ignored above.
3319  if (isa<ExtVectorElementExpr>(E->getBase())) {
3320  LValue LV = EmitLValue(E->getBase());
3321  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3323 
3324  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3325  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3326  SignedIndices, E->getExprLoc());
3327  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3328  CGM.getTBAAInfoForSubobject(LV, EltType));
3329  }
3330 
3331  LValueBaseInfo EltBaseInfo;
3332  TBAAAccessInfo EltTBAAInfo;
3333  Address Addr = Address::invalid();
3334  if (const VariableArrayType *vla =
3335  getContext().getAsVariableArrayType(E->getType())) {
3336  // The base must be a pointer, which is not an aggregate. Emit
3337  // it. It needs to be emitted first in case it's what captures
3338  // the VLA bounds.
3339  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3340  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3341 
3342  // The element count here is the total number of non-VLA elements.
3343  llvm::Value *numElements = getVLASize(vla).NumElts;
3344 
3345  // Effectively, the multiply by the VLA size is part of the GEP.
3346  // GEP indexes are signed, and scaling an index isn't permitted to
3347  // signed-overflow, so we use the same semantics for our explicit
3348  // multiply. We suppress this if overflow is not undefined behavior.
3349  if (getLangOpts().isSignedOverflowDefined()) {
3350  Idx = Builder.CreateMul(Idx, numElements);
3351  } else {
3352  Idx = Builder.CreateNSWMul(Idx, numElements);
3353  }
3354 
3355  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3357  SignedIndices, E->getExprLoc());
3358 
3359  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3360  // Indexing over an interface, as in "NSString *P; P[4];"
3361 
3362  // Emit the base pointer.
3363  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3364  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3365 
3366  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3367  llvm::Value *InterfaceSizeVal =
3368  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3369 
3370  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3371 
3372  // We don't necessarily build correct LLVM struct types for ObjC
3373  // interfaces, so we can't rely on GEP to do this scaling
3374  // correctly, so we need to cast to i8*. FIXME: is this actually
3375  // true? A lot of other things in the fragile ABI would break...
3376  llvm::Type *OrigBaseTy = Addr.getType();
3377  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3378 
3379  // Do the GEP.
3380  CharUnits EltAlign =
3381  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3382  llvm::Value *EltPtr =
3383  emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3384  SignedIndices, E->getExprLoc());
3385  Addr = Address(EltPtr, EltAlign);
3386 
3387  // Cast back.
3388  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3389  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3390  // If this is A[i] where A is an array, the frontend will have decayed the
3391  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3392  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3393  // "gep x, i" here. Emit one "gep A, 0, i".
3394  assert(Array->getType()->isArrayType() &&
3395  "Array to pointer decay must have array source type!");
3396  LValue ArrayLV;
3397  // For simple multidimensional array indexing, set the 'accessed' flag for
3398  // better bounds-checking of the base expression.
3399  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3400  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3401  else
3402  ArrayLV = EmitLValue(Array);
3403  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3404 
3405  // Propagate the alignment from the array itself to the result.
3406  Addr = emitArraySubscriptGEP(
3407  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3408  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3409  E->getExprLoc());
3410  EltBaseInfo = ArrayLV.getBaseInfo();
3411  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3412  } else {
3413  // The base must be a pointer; emit it with an estimate of its alignment.
3414  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3415  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3416  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3418  SignedIndices, E->getExprLoc());
3419  }
3420 
3421  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3422 
3423  if (getLangOpts().ObjC1 &&
3424  getLangOpts().getGC() != LangOptions::NonGC) {
3426  setObjCGCLValueClass(getContext(), E, LV);
3427  }
3428  return LV;
3429 }
3430 
3432  LValueBaseInfo &BaseInfo,
3433  TBAAAccessInfo &TBAAInfo,
3434  QualType BaseTy, QualType ElTy,
3435  bool IsLowerBound) {
3436  LValue BaseLVal;
3437  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3438  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3439  if (BaseTy->isArrayType()) {
3440  Address Addr = BaseLVal.getAddress();
3441  BaseInfo = BaseLVal.getBaseInfo();
3442 
3443  // If the array type was an incomplete type, we need to make sure
3444  // the decay ends up being the right type.
3445  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3446  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3447 
3448  // Note that VLA pointers are always decayed, so we don't need to do
3449  // anything here.
3450  if (!BaseTy->isVariableArrayType()) {
3451  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3452  "Expected pointer to array");
3453  Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3454  "arraydecay");
3455  }
3456 
3457  return CGF.Builder.CreateElementBitCast(Addr,
3458  CGF.ConvertTypeForMem(ElTy));
3459  }
3460  LValueBaseInfo TypeBaseInfo;
3461  TBAAAccessInfo TypeTBAAInfo;
3462  CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3463  &TypeTBAAInfo);
3464  BaseInfo.mergeForCast(TypeBaseInfo);
3465  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3466  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3467  }
3468  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3469 }
3470 
3472  bool IsLowerBound) {
3474  QualType ResultExprTy;
3475  if (auto *AT = getContext().getAsArrayType(BaseTy))
3476  ResultExprTy = AT->getElementType();
3477  else
3478  ResultExprTy = BaseTy->getPointeeType();
3479  llvm::Value *Idx = nullptr;
3480  if (IsLowerBound || E->getColonLoc().isInvalid()) {
3481  // Requesting lower bound or upper bound, but without provided length and
3482  // without ':' symbol for the default length -> length = 1.
3483  // Idx = LowerBound ?: 0;
3484  if (auto *LowerBound = E->getLowerBound()) {
3485  Idx = Builder.CreateIntCast(
3486  EmitScalarExpr(LowerBound), IntPtrTy,
3487  LowerBound->getType()->hasSignedIntegerRepresentation());
3488  } else
3489  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3490  } else {
3491  // Try to emit length or lower bound as constant. If this is possible, 1
3492  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3493  // IR (LB + Len) - 1.
3494  auto &C = CGM.getContext();
3495  auto *Length = E->getLength();
3496  llvm::APSInt ConstLength;
3497  if (Length) {
3498  // Idx = LowerBound + Length - 1;
3499  if (Length->isIntegerConstantExpr(ConstLength, C)) {
3500  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3501  Length = nullptr;
3502  }
3503  auto *LowerBound = E->getLowerBound();
3504  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3505  if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3506  ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3507  LowerBound = nullptr;
3508  }
3509  if (!Length)
3510  --ConstLength;
3511  else if (!LowerBound)
3512  --ConstLowerBound;
3513 
3514  if (Length || LowerBound) {
3515  auto *LowerBoundVal =
3516  LowerBound
3517  ? Builder.CreateIntCast(
3518  EmitScalarExpr(LowerBound), IntPtrTy,
3519  LowerBound->getType()->hasSignedIntegerRepresentation())
3520  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3521  auto *LengthVal =
3522  Length
3523  ? Builder.CreateIntCast(
3524  EmitScalarExpr(Length), IntPtrTy,
3525  Length->getType()->hasSignedIntegerRepresentation())
3526  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3527  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3528  /*HasNUW=*/false,
3529  !getLangOpts().isSignedOverflowDefined());
3530  if (Length && LowerBound) {
3531  Idx = Builder.CreateSub(
3532  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3533  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3534  }
3535  } else
3536  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3537  } else {
3538  // Idx = ArraySize - 1;
3539  QualType ArrayTy = BaseTy->isPointerType()
3540  ? E->getBase()->IgnoreParenImpCasts()->getType()
3541  : BaseTy;
3542  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3543  Length = VAT->getSizeExpr();
3544  if (Length->isIntegerConstantExpr(ConstLength, C))
3545  Length = nullptr;
3546  } else {
3547  auto *CAT = C.getAsConstantArrayType(ArrayTy);
3548  ConstLength = CAT->getSize();
3549  }
3550  if (Length) {
3551  auto *LengthVal = Builder.CreateIntCast(
3552  EmitScalarExpr(Length), IntPtrTy,
3553  Length->getType()->hasSignedIntegerRepresentation());
3554  Idx = Builder.CreateSub(
3555  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3556  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3557  } else {
3558  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3559  --ConstLength;
3560  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3561  }
3562  }
3563  }
3564  assert(Idx);
3565 
3566  Address EltPtr = Address::invalid();
3567  LValueBaseInfo BaseInfo;
3568  TBAAAccessInfo TBAAInfo;
3569  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3570  // The base must be a pointer, which is not an aggregate. Emit
3571  // it. It needs to be emitted first in case it's what captures
3572  // the VLA bounds.
3573  Address Base =
3574  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3575  BaseTy, VLA->getElementType(), IsLowerBound);
3576  // The element count here is the total number of non-VLA elements.
3577  llvm::Value *NumElements = getVLASize(VLA).NumElts;
3578 
3579  // Effectively, the multiply by the VLA size is part of the GEP.
3580  // GEP indexes are signed, and scaling an index isn't permitted to
3581  // signed-overflow, so we use the same semantics for our explicit
3582  // multiply. We suppress this if overflow is not undefined behavior.
3583  if (getLangOpts().isSignedOverflowDefined())
3584  Idx = Builder.CreateMul(Idx, NumElements);
3585  else
3586  Idx = Builder.CreateNSWMul(Idx, NumElements);
3587  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3589  /*SignedIndices=*/false, E->getExprLoc());
3590  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3591  // If this is A[i] where A is an array, the frontend will have decayed the
3592  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3593  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3594  // "gep x, i" here. Emit one "gep A, 0, i".
3595  assert(Array->getType()->isArrayType() &&
3596  "Array to pointer decay must have array source type!");
3597  LValue ArrayLV;
3598  // For simple multidimensional array indexing, set the 'accessed' flag for
3599  // better bounds-checking of the base expression.
3600  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3601  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3602  else
3603  ArrayLV = EmitLValue(Array);
3604 
3605  // Propagate the alignment from the array itself to the result.
3606  EltPtr = emitArraySubscriptGEP(
3607  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3608  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3609  /*SignedIndices=*/false, E->getExprLoc());
3610  BaseInfo = ArrayLV.getBaseInfo();
3611  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3612  } else {
3613  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3614  TBAAInfo, BaseTy, ResultExprTy,
3615  IsLowerBound);
3616  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3617  !getLangOpts().isSignedOverflowDefined(),
3618  /*SignedIndices=*/false, E->getExprLoc());
3619  }
3620 
3621  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3622 }
3623 
3626  // Emit the base vector as an l-value.
3627  LValue Base;
3628 
3629  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3630  if (E->isArrow()) {
3631  // If it is a pointer to a vector, emit the address and form an lvalue with
3632  // it.
3633  LValueBaseInfo BaseInfo;
3634  TBAAAccessInfo TBAAInfo;
3635  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3636  const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3637  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3638  Base.getQuals().removeObjCGCAttr();
3639  } else if (E->getBase()->isGLValue()) {
3640  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3641  // emit the base as an lvalue.
3642  assert(E->getBase()->getType()->isVectorType());
3643  Base = EmitLValue(E->getBase());
3644  } else {
3645  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3646  assert(E->getBase()->getType()->isVectorType() &&
3647  "Result must be a vector");
3648  llvm::Value *Vec = EmitScalarExpr(E->getBase());
3649 
3650  // Store the vector to memory (because LValue wants an address).
3651  Address VecMem = CreateMemTemp(E->getBase()->getType());
3652  Builder.CreateStore(Vec, VecMem);
3653  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3655  }
3656 
3657  QualType type =
3659 
3660  // Encode the element access list into a vector of unsigned indices.
3661  SmallVector<uint32_t, 4> Indices;
3662  E->getEncodedElementAccess(Indices);
3663 
3664  if (Base.isSimple()) {
3665  llvm::Constant *CV =
3666  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3667  return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3668  Base.getBaseInfo(), TBAAAccessInfo());
3669  }
3670  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3671 
3672  llvm::Constant *BaseElts = Base.getExtVectorElts();
3674 
3675  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3676  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3677  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3679  Base.getBaseInfo(), TBAAAccessInfo());
3680 }
3681 
3683  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3684  EmitIgnoredExpr(E->getBase());
3685  return EmitDeclRefLValue(DRE);
3686  }
3687 
3688  Expr *BaseExpr = E->getBase();
3689  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3690  LValue BaseLV;
3691  if (E->isArrow()) {
3692  LValueBaseInfo BaseInfo;
3693  TBAAAccessInfo TBAAInfo;
3694  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3695  QualType PtrTy = BaseExpr->getType()->getPointeeType();
3696  SanitizerSet SkippedChecks;
3697  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3698  if (IsBaseCXXThis)
3699  SkippedChecks.set(SanitizerKind::Alignment, true);
3700  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3701  SkippedChecks.set(SanitizerKind::Null, true);
3702  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3703  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3704  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3705  } else
3706  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3707 
3708  NamedDecl *ND = E->getMemberDecl();
3709  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3710  LValue LV = EmitLValueForField(BaseLV, Field);
3711  setObjCGCLValueClass(getContext(), E, LV);
3712  return LV;
3713  }
3714 
3715  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3716  return EmitFunctionDeclLValue(*this, E, FD);
3717 
3718  llvm_unreachable("Unhandled member declaration!");
3719 }
3720 
3721 /// Given that we are currently emitting a lambda, emit an l-value for
3722 /// one of its members.
3724  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3725  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3726  QualType LambdaTagType =
3727  getContext().getTagDeclType(Field->getParent());
3728  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3729  return EmitLValueForField(LambdaLV, Field);
3730 }
3731 
3732 /// Drill down to the storage of a field without walking into
3733 /// reference types.
3734 ///
3735 /// The resulting address doesn't necessarily have the right type.
3737  const FieldDecl *field) {
3738  const RecordDecl *rec = field->getParent();
3739 
3740  unsigned idx =
3741  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3742 
3743  CharUnits offset;
3744  // Adjust the alignment down to the given offset.
3745  // As a special case, if the LLVM field index is 0, we know that this
3746  // is zero.
3747  assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3748  .getFieldOffset(field->getFieldIndex()) == 0) &&
3749  "LLVM field at index zero had non-zero offset?");
3750  if (idx != 0) {
3751  auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3752  auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3753  offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3754  }
3755 
3756  return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3757 }
3758 
3759 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3760  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3761  if (!RD)
3762  return false;
3763 
3764  if (RD->isDynamicClass())
3765  return true;
3766 
3767  for (const auto &Base : RD->bases())
3768  if (hasAnyVptr(Base.getType(), Context))
3769  return true;
3770 
3771  for (const FieldDecl *Field : RD->fields())
3772  if (hasAnyVptr(Field->getType(), Context))
3773  return true;
3774 
3775  return false;
3776 }
3777 
3779  const FieldDecl *field) {
3780  LValueBaseInfo BaseInfo = base.getBaseInfo();
3781 
3782  if (field->isBitField()) {
3783  const CGRecordLayout &RL =
3785  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3786  Address Addr = base.getAddress();
3787  unsigned Idx = RL.getLLVMFieldNo(field);
3788  if (Idx != 0)
3789  // For structs, we GEP to the field that the record layout suggests.
3790  Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3791  field->getName());
3792  // Get the access type.
3793  llvm::Type *FieldIntTy =
3794  llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3795  if (Addr.getElementType() != FieldIntTy)
3796  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3797 
3798  QualType fieldType =
3799  field->getType().withCVRQualifiers(base.getVRQualifiers());
3800  // TODO: Support TBAA for bit fields.
3801  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
3802  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
3803  TBAAAccessInfo());
3804  }
3805 
3806  // Fields of may-alias structures are may-alias themselves.
3807  // FIXME: this should get propagated down through anonymous structs
3808  // and unions.
3809  QualType FieldType = field->getType();
3810  const RecordDecl *rec = field->getParent();
3811  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
3812  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
3813  TBAAAccessInfo FieldTBAAInfo;
3814  if (base.getTBAAInfo().isMayAlias() ||
3815  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
3816  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3817  } else if (rec->isUnion()) {
3818  // TODO: Support TBAA for unions.
3819  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3820  } else {
3821  // If no base type been assigned for the base access, then try to generate
3822  // one for this base lvalue.
3823  FieldTBAAInfo = base.getTBAAInfo();
3824  if (!FieldTBAAInfo.BaseType) {
3825  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
3826  assert(!FieldTBAAInfo.Offset &&
3827  "Nonzero offset for an access with no base type!");
3828  }
3829 
3830  // Adjust offset to be relative to the base type.
3831  const ASTRecordLayout &Layout =
3833  unsigned CharWidth = getContext().getCharWidth();
3834  if (FieldTBAAInfo.BaseType)
3835  FieldTBAAInfo.Offset +=
3836  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
3837 
3838  // Update the final access type and size.
3839  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
3840  FieldTBAAInfo.Size =
3841  getContext().getTypeSizeInChars(FieldType).getQuantity();
3842  }
3843 
3844  Address addr = base.getAddress();
3845  unsigned RecordCVR = base.getVRQualifiers();
3846  if (rec->isUnion()) {
3847  // For unions, there is no pointer adjustment.
3848  assert(!FieldType->isReferenceType() && "union has reference member");
3849  if (CGM.getCodeGenOpts().StrictVTablePointers &&
3850  hasAnyVptr(FieldType, getContext()))
3851  // Because unions can easily skip invariant.barriers, we need to add
3852  // a barrier every time CXXRecord field with vptr is referenced.
3853  addr = Address(Builder.CreateInvariantGroupBarrier(addr.getPointer()),
3854  addr.getAlignment());
3855  } else {
3856  // For structs, we GEP to the field that the record layout suggests.
3857  addr = emitAddrOfFieldStorage(*this, addr, field);
3858 
3859  // If this is a reference field, load the reference right now.
3860  if (FieldType->isReferenceType()) {
3861  LValue RefLVal = MakeAddrLValue(addr, FieldType, FieldBaseInfo,
3862  FieldTBAAInfo);
3863  if (RecordCVR & Qualifiers::Volatile)
3864  RefLVal.getQuals().setVolatile(true);
3865  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
3866 
3867  // Qualifiers on the struct don't apply to the referencee.
3868  RecordCVR = 0;
3869  FieldType = FieldType->getPointeeType();
3870  }
3871  }
3872 
3873  // Make sure that the address is pointing to the right type. This is critical
3874  // for both unions and structs. A union needs a bitcast, a struct element
3875  // will need a bitcast if the LLVM type laid out doesn't match the desired
3876  // type.
3878  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
3879 
3880  if (field->hasAttr<AnnotateAttr>())
3881  addr = EmitFieldAnnotations(field, addr);
3882 
3883  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
3884  LV.getQuals().addCVRQualifiers(RecordCVR);
3885 
3886  // __weak attribute on a field is ignored.
3887  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3888  LV.getQuals().removeObjCGCAttr();
3889 
3890  return LV;
3891 }
3892 
3893 LValue
3895  const FieldDecl *Field) {
3896  QualType FieldType = Field->getType();
3897 
3898  if (!FieldType->isReferenceType())
3899  return EmitLValueForField(Base, Field);
3900 
3901  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3902 
3903  // Make sure that the address is pointing to the right type.
3904  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3905  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3906 
3907  // TODO: Generate TBAA information that describes this access as a structure
3908  // member access and not just an access to an object of the field's type. This
3909  // should be similar to what we do in EmitLValueForField().
3910  LValueBaseInfo BaseInfo = Base.getBaseInfo();
3911  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
3912  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
3913  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
3914  CGM.getTBAAInfoForSubobject(Base, FieldType));
3915 }
3916 
3918  if (E->isFileScope()) {
3920  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3921  }
3922  if (E->getType()->isVariablyModifiedType())
3923  // make sure to emit the VLA size.
3925 
3926  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3927  const Expr *InitExpr = E->getInitializer();
3928  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
3929 
3930  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3931  /*Init*/ true);
3932 
3933  return Result;
3934 }
3935 
3937  if (!E->isGLValue())
3938  // Initializing an aggregate temporary in C++11: T{...}.
3939  return EmitAggExprToLValue(E);
3940 
3941  // An lvalue initializer list must be initializing a reference.
3942  assert(E->isTransparent() && "non-transparent glvalue init list");
3943  return EmitLValue(E->getInit(0));
3944 }
3945 
3946 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3947 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3948 /// LValue is returned and the current block has been terminated.
3950  const Expr *Operand) {
3951  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3952  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3953  return None;
3954  }
3955 
3956  return CGF.EmitLValue(Operand);
3957 }
3958 
3961  if (!expr->isGLValue()) {
3962  // ?: here should be an aggregate.
3963  assert(hasAggregateEvaluationKind(expr->getType()) &&
3964  "Unexpected conditional operator!");
3965  return EmitAggExprToLValue(expr);
3966  }
3967 
3968  OpaqueValueMapping binding(*this, expr);
3969 
3970  const Expr *condExpr = expr->getCond();
3971  bool CondExprBool;
3972  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3973  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
3974  if (!CondExprBool) std::swap(live, dead);
3975 
3976  if (!ContainsLabel(dead)) {
3977  // If the true case is live, we need to track its region.
3978  if (CondExprBool)
3980  return EmitLValue(live);
3981  }
3982  }
3983 
3984  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
3985  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
3986  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
3987 
3988  ConditionalEvaluation eval(*this);
3989  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
3990 
3991  // Any temporaries created here are conditional.
3992  EmitBlock(lhsBlock);
3994  eval.begin(*this);
3995  Optional<LValue> lhs =
3996  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
3997  eval.end(*this);
3998 
3999  if (lhs && !lhs->isSimple())
4000  return EmitUnsupportedLValue(expr, "conditional operator");
4001 
4002  lhsBlock = Builder.GetInsertBlock();
4003  if (lhs)
4004  Builder.CreateBr(contBlock);
4005 
4006  // Any temporaries created here are conditional.
4007  EmitBlock(rhsBlock);
4008  eval.begin(*this);
4009  Optional<LValue> rhs =
4010  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4011  eval.end(*this);
4012  if (rhs && !rhs->isSimple())
4013  return EmitUnsupportedLValue(expr, "conditional operator");
4014  rhsBlock = Builder.GetInsertBlock();
4015 
4016  EmitBlock(contBlock);
4017 
4018  if (lhs && rhs) {
4019  llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4020  2, "cond-lvalue");
4021  phi->addIncoming(lhs->getPointer(), lhsBlock);
4022  phi->addIncoming(rhs->getPointer(), rhsBlock);
4023  Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4024  AlignmentSource alignSource =
4025  std::max(lhs->getBaseInfo().getAlignmentSource(),
4026  rhs->getBaseInfo().getAlignmentSource());
4028  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4029  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4030  TBAAInfo);
4031  } else {
4032  assert((lhs || rhs) &&
4033  "both operands of glvalue conditional are throw-expressions?");
4034  return lhs ? *lhs : *rhs;
4035  }
4036 }
4037 
4038 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4039 /// type. If the cast is to a reference, we can have the usual lvalue result,
4040 /// otherwise if a cast is needed by the code generator in an lvalue context,
4041 /// then it must mean that we need the address of an aggregate in order to
4042 /// access one of its members. This can happen for all the reasons that casts
4043 /// are permitted with aggregate result, including noop aggregate casts, and
4044 /// cast from scalar to union.
4046  switch (E->getCastKind()) {
4047  case CK_ToVoid:
4048  case CK_BitCast:
4049  case CK_ArrayToPointerDecay:
4050  case CK_FunctionToPointerDecay:
4051  case CK_NullToMemberPointer:
4052  case CK_NullToPointer:
4053  case CK_IntegralToPointer:
4054  case CK_PointerToIntegral:
4055  case CK_PointerToBoolean:
4056  case CK_VectorSplat:
4057  case CK_IntegralCast:
4058  case CK_BooleanToSignedIntegral:
4059  case CK_IntegralToBoolean:
4060  case CK_IntegralToFloating:
4061  case CK_FloatingToIntegral:
4062  case CK_FloatingToBoolean:
4063  case CK_FloatingCast:
4064  case CK_FloatingRealToComplex:
4065  case CK_FloatingComplexToReal:
4066  case CK_FloatingComplexToBoolean:
4067  case CK_FloatingComplexCast:
4068  case CK_FloatingComplexToIntegralComplex:
4069  case CK_IntegralRealToComplex:
4070  case CK_IntegralComplexToReal:
4071  case CK_IntegralComplexToBoolean:
4072  case CK_IntegralComplexCast:
4073  case CK_IntegralComplexToFloatingComplex:
4074  case CK_DerivedToBaseMemberPointer:
4075  case CK_BaseToDerivedMemberPointer:
4076  case CK_MemberPointerToBoolean:
4077  case CK_ReinterpretMemberPointer:
4078  case CK_AnyPointerToBlockPointerCast:
4079  case CK_ARCProduceObject:
4080  case CK_ARCConsumeObject:
4081  case CK_ARCReclaimReturnedObject:
4082  case CK_ARCExtendBlockObject:
4083  case CK_CopyAndAutoreleaseBlockObject:
4084  case CK_AddressSpaceConversion:
4085  case CK_IntToOCLSampler:
4086  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4087 
4088  case CK_Dependent:
4089  llvm_unreachable("dependent cast kind in IR gen!");
4090 
4091  case CK_BuiltinFnToFnPtr:
4092  llvm_unreachable("builtin functions are handled elsewhere");
4093 
4094  // These are never l-values; just use the aggregate emission code.
4095  case CK_NonAtomicToAtomic:
4096  case CK_AtomicToNonAtomic:
4097  return EmitAggExprToLValue(E);
4098 
4099  case CK_Dynamic: {
4100  LValue LV = EmitLValue(E->getSubExpr());
4101  Address V = LV.getAddress();
4102  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4103  return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4104  }
4105 
4106  case CK_ConstructorConversion:
4107  case CK_UserDefinedConversion:
4108  case CK_CPointerToObjCPointerCast:
4109  case CK_BlockPointerToObjCPointerCast:
4110  case CK_NoOp:
4111  case CK_LValueToRValue:
4112  return EmitLValue(E->getSubExpr());
4113 
4114  case CK_UncheckedDerivedToBase:
4115  case CK_DerivedToBase: {
4116  const RecordType *DerivedClassTy =
4117  E->getSubExpr()->getType()->getAs<RecordType>();
4118  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4119 
4120  LValue LV = EmitLValue(E->getSubExpr());
4121  Address This = LV.getAddress();
4122 
4123  // Perform the derived-to-base conversion
4125  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4126  /*NullCheckValue=*/false, E->getExprLoc());
4127 
4128  // TODO: Support accesses to members of base classes in TBAA. For now, we
4129  // conservatively pretend that the complete object is of the base class
4130  // type.
4131  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4132  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4133  }
4134  case CK_ToUnion:
4135  return EmitAggExprToLValue(E);
4136  case CK_BaseToDerived: {
4137  const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4138  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4139 
4140  LValue LV = EmitLValue(E->getSubExpr());
4141 
4142  // Perform the base-to-derived conversion
4143  Address Derived =
4144  GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4145  E->path_begin(), E->path_end(),
4146  /*NullCheckValue=*/false);
4147 
4148  // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4149  // performed and the object is not of the derived type.
4152  Derived.getPointer(), E->getType());
4153 
4154  if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4155  EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4156  /*MayBeNull=*/false,
4158 
4159  return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4160  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4161  }
4162  case CK_LValueBitCast: {
4163  // This must be a reinterpret_cast (or c-style equivalent).
4164  const auto *CE = cast<ExplicitCastExpr>(E);
4165 
4166  CGM.EmitExplicitCastExprType(CE, this);
4167  LValue LV = EmitLValue(E->getSubExpr());
4169  ConvertType(CE->getTypeAsWritten()));
4170 
4171  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4172  EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4173  /*MayBeNull=*/false,
4175 
4176  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4177  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4178  }
4179  case CK_ObjCObjectLValueCast: {
4180  LValue LV = EmitLValue(E->getSubExpr());
4182  ConvertType(E->getType()));
4183  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4184  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4185  }
4186  case CK_ZeroToOCLQueue:
4187  llvm_unreachable("NULL to OpenCL queue lvalue cast is not valid");
4188  case CK_ZeroToOCLEvent:
4189  llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
4190  }
4191 
4192  llvm_unreachable("Unhandled lvalue cast kind?");
4193 }
4194 
4198 }
4199 
4200 LValue
4203 
4204  llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4205  it = OpaqueLValues.find(e);
4206 
4207  if (it != OpaqueLValues.end())
4208  return it->second;
4209 
4210  assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4211  return EmitLValue(e->getSourceExpr());
4212 }
4213 
4214 RValue
4217 
4218  llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4219  it = OpaqueRValues.find(e);
4220 
4221  if (it != OpaqueRValues.end())
4222  return it->second;
4223 
4224  assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4225  return EmitAnyExpr(e->getSourceExpr());
4226 }
4227 
4229  const FieldDecl *FD,
4230  SourceLocation Loc) {
4231  QualType FT = FD->getType();
4232  LValue FieldLV = EmitLValueForField(LV, FD);
4233  switch (getEvaluationKind(FT)) {
4234  case TEK_Complex:
4235  return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4236  case TEK_Aggregate:
4237  return FieldLV.asAggregateRValue();
4238  case TEK_Scalar:
4239  // This routine is used to load fields one-by-one to perform a copy, so
4240  // don't load reference fields.
4241  if (FD->getType()->isReferenceType())
4242  return RValue::get(FieldLV.getPointer());
4243  return EmitLoadOfLValue(FieldLV, Loc);
4244  }
4245  llvm_unreachable("bad evaluation kind");
4246 }
4247 
4248 //===--------------------------------------------------------------------===//
4249 // Expression Emission
4250 //===--------------------------------------------------------------------===//
4251 
4254  // Builtins never have block type.
4255  if (E->getCallee()->getType()->isBlockPointerType())
4256  return EmitBlockCallExpr(E, ReturnValue);
4257 
4258  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4259  return EmitCXXMemberCallExpr(CE, ReturnValue);
4260 
4261  if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4262  return EmitCUDAKernelCallExpr(CE, ReturnValue);
4263 
4264  if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4265  if (const CXXMethodDecl *MD =
4266  dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4267  return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4268 
4269  CGCallee callee = EmitCallee(E->getCallee());
4270 
4271  if (callee.isBuiltin()) {
4272  return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4273  E, ReturnValue);
4274  }
4275 
4276  if (callee.isPseudoDestructor()) {
4278  }
4279 
4280  return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4281 }
4282 
4283 /// Emit a CallExpr without considering whether it might be a subclass.
4286  CGCallee Callee = EmitCallee(E->getCallee());
4287  return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4288 }
4289 
4291  if (auto builtinID = FD->getBuiltinID()) {
4292  return CGCallee::forBuiltin(builtinID, FD);
4293  }
4294 
4295  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4296  return CGCallee::forDirect(calleePtr, FD);
4297 }
4298 
4300  E = E->IgnoreParens();
4301 
4302  // Look through function-to-pointer decay.
4303  if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4304  if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4305  ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4306  return EmitCallee(ICE->getSubExpr());
4307  }
4308 
4309  // Resolve direct calls.
4310  } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4311  if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4312  return EmitDirectCallee(*this, FD);
4313  }
4314  } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4315  if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4316  EmitIgnoredExpr(ME->getBase());
4317  return EmitDirectCallee(*this, FD);
4318  }
4319 
4320  // Look through template substitutions.
4321  } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4322  return EmitCallee(NTTP->getReplacement());
4323 
4324  // Treat pseudo-destructor calls differently.
4325  } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4326  return CGCallee::forPseudoDestructor(PDE);
4327  }
4328 
4329  // Otherwise, we have an indirect reference.
4330  llvm::Value *calleePtr;
4332  if (auto ptrType = E->getType()->getAs<PointerType>()) {
4333  calleePtr = EmitScalarExpr(E);
4334  functionType = ptrType->getPointeeType();
4335  } else {
4336  functionType = E->getType();
4337  calleePtr = EmitLValue(E).getPointer();
4338  }
4339  assert(functionType->isFunctionType());
4340  CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
4342  CGCallee callee(calleeInfo, calleePtr);
4343  return callee;
4344 }
4345 
4347  // Comma expressions just emit their LHS then their RHS as an l-value.
4348  if (E->getOpcode() == BO_Comma) {
4349  EmitIgnoredExpr(E->getLHS());
4351  return EmitLValue(E->getRHS());
4352  }
4353 
4354  if (E->getOpcode() == BO_PtrMemD ||
4355  E->getOpcode() == BO_PtrMemI)
4357 
4358  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4359 
4360  // Note that in all of these cases, __block variables need the RHS
4361  // evaluated first just in case the variable gets moved by the RHS.
4362 
4363  switch (getEvaluationKind(E->getType())) {
4364  case TEK_Scalar: {
4365  switch (E->getLHS()->getType().getObjCLifetime()) {
4367  return EmitARCStoreStrong(E, /*ignored*/ false).first;
4368 
4370  return EmitARCStoreAutoreleasing(E).first;
4371 
4372  // No reason to do any of these differently.
4373  case Qualifiers::OCL_None:
4375  case Qualifiers::OCL_Weak:
4376  break;
4377  }
4378 
4379  RValue RV = EmitAnyExpr(E->getRHS());
4381  if (RV.isScalar())
4383  EmitStoreThroughLValue(RV, LV);
4384  return LV;
4385  }
4386 
4387  case TEK_Complex:
4388  return EmitComplexAssignmentLValue(E);
4389 
4390  case TEK_Aggregate:
4391  return EmitAggExprToLValue(E);
4392  }
4393  llvm_unreachable("bad evaluation kind");
4394 }
4395 
4397  RValue RV = EmitCallExpr(E);
4398 
4399  if (!RV.isScalar())
4400  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4402 
4403  assert(E->getCallReturnType(getContext())->isReferenceType() &&
4404  "Can't have a scalar return unless the return type is a "
4405  "reference type!");
4406 
4408 }
4409 
4411  // FIXME: This shouldn't require another copy.
4412  return EmitAggExprToLValue(E);
4413 }
4414 
4417  && "binding l-value to type which needs a temporary");
4418  AggValueSlot Slot = CreateAggTemp(E->getType());
4419  EmitCXXConstructExpr(E, Slot);
4420  return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4421 }
4422 
4423 LValue
4426 }
4427 
4430  ConvertType(E->getType()));
4431 }
4432 
4434  return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4436 }
4437 
4438 LValue
4440  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4441  Slot.setExternallyDestructed();
4442  EmitAggExpr(E->getSubExpr(), Slot);
4443  EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4445 }
4446 
4447 LValue
4449  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4450  EmitLambdaExpr(E, Slot);
4452 }
4453 
4455  RValue RV = EmitObjCMessageExpr(E);
4456 
4457  if (!RV.isScalar())
4458  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4460 
4461  assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4462  "Can't have a scalar return unless the return type is a "
4463  "reference type!");
4464 
4466 }
4467 
4469  Address V =
4471  return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4472 }
4473 
4475  const ObjCIvarDecl *Ivar) {
4476  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4477 }
4478 
4480  llvm::Value *BaseValue,
4481  const ObjCIvarDecl *Ivar,
4482  unsigned CVRQualifiers) {
4483  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4484  Ivar, CVRQualifiers);
4485 }
4486 
4488  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4489  llvm::Value *BaseValue = nullptr;
4490  const Expr *BaseExpr = E->getBase();
4491  Qualifiers BaseQuals;
4492  QualType ObjectTy;
4493  if (E->isArrow()) {
4494  BaseValue = EmitScalarExpr(BaseExpr);
4495  ObjectTy = BaseExpr->getType()->getPointeeType();
4496  BaseQuals = ObjectTy.getQualifiers();
4497  } else {
4498  LValue BaseLV = EmitLValue(BaseExpr);
4499  BaseValue = BaseLV.getPointer();
4500  ObjectTy = BaseExpr->getType();
4501  BaseQuals = ObjectTy.getQualifiers();
4502  }
4503 
4504  LValue LV =
4505  EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4506  BaseQuals.getCVRQualifiers());
4507  setObjCGCLValueClass(getContext(), E, LV);
4508  return LV;
4509 }
4510 
4512  // Can only get l-value for message expression returning aggregate type
4513  RValue RV = EmitAnyExprToTemp(E);
4514  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4516 }
4517 
4518 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4520  llvm::Value *Chain) {
4521  // Get the actual function type. The callee type will always be a pointer to
4522  // function type or a block pointer type.
4523  assert(CalleeType->isFunctionPointerType() &&
4524  "Call must have function pointer type!");
4525 
4526  const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
4527 
4528  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4529  // We can only guarantee that a function is called from the correct
4530  // context/function based on the appropriate target attributes,
4531  // so only check in the case where we have both always_inline and target
4532  // since otherwise we could be making a conditional call after a check for
4533  // the proper cpu features (and it won't cause code generation issues due to
4534  // function based code generation).
4535  if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4536  TargetDecl->hasAttr<TargetAttr>())
4537  checkTargetFeatures(E, FD);
4538 
4539  CalleeType = getContext().getCanonicalType(CalleeType);
4540 
4541  auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4542 
4543  CGCallee Callee = OrigCallee;
4544 
4545  if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4546  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4547  if (llvm::Constant *PrefixSig =
4549  SanitizerScope SanScope(this);
4550  // Remove any (C++17) exception specifications, to allow calling e.g. a
4551  // noexcept function through a non-noexcept pointer.
4552  auto ProtoTy =
4554  llvm::Constant *FTRTTIConst =
4555  CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4556  llvm::Type *PrefixStructTyElems[] = {PrefixSig->getType(), Int32Ty};
4557  llvm::StructType *PrefixStructTy = llvm::StructType::get(
4558  CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4559 
4560  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4561 
4562  llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4563  CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4564  llvm::Value *CalleeSigPtr =
4565  Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4566  llvm::Value *CalleeSig =
4567  Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4568  llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4569 
4570  llvm::BasicBlock *Cont = createBasicBlock("cont");
4571  llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4572  Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4573 
4574  EmitBlock(TypeCheck);
4575  llvm::Value *CalleeRTTIPtr =
4576  Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4577  llvm::Value *CalleeRTTIEncoded =
4578  Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4579  llvm::Value *CalleeRTTI =
4580  DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
4581  llvm::Value *CalleeRTTIMatch =
4582  Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4583  llvm::Constant *StaticData[] = {
4585  EmitCheckTypeDescriptor(CalleeType)
4586  };
4587  EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4588  SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4589 
4590  Builder.CreateBr(Cont);
4591  EmitBlock(Cont);
4592  }
4593  }
4594 
4595  const auto *FnType = cast<FunctionType>(PointeeType);
4596 
4597  // If we are checking indirect calls and this call is indirect, check that the
4598  // function pointer is a member of the bit set for the function type.
4599  if (SanOpts.has(SanitizerKind::CFIICall) &&
4600  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4601  SanitizerScope SanScope(this);
4602  EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4603 
4604  llvm::Metadata *MD;
4605  if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
4607  else
4608  MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4609 
4610  llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4611 
4612  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4613  llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4614  llvm::Value *TypeTest = Builder.CreateCall(
4615  CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4616 
4617  auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4618  llvm::Constant *StaticData[] = {
4619  llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4621  EmitCheckTypeDescriptor(QualType(FnType, 0)),
4622  };
4623  if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4624  EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4625  CastedCallee, StaticData);
4626  } else {
4627  EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4628  SanitizerHandler::CFICheckFail, StaticData,
4629  {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4630  }
4631  }
4632 
4633  CallArgList Args;
4634  if (Chain)
4637 
4638  // C++17 requires that we evaluate arguments to a call using assignment syntax
4639  // right-to-left, and that we evaluate arguments to certain other operators
4640  // left-to-right. Note that we allow this to override the order dictated by
4641  // the calling convention on the MS ABI, which means that parameter
4642  // destruction order is not necessarily reverse construction order.
4643  // FIXME: Revisit this based on C++ committee response to unimplementability.
4645  if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4646  if (OCE->isAssignmentOp())
4648  else {
4649  switch (OCE->getOperator()) {
4650  case OO_LessLess:
4651  case OO_GreaterGreater:
4652  case OO_AmpAmp:
4653  case OO_PipePipe:
4654  case OO_Comma:
4655  case OO_ArrowStar:
4657  break;
4658  default:
4659  break;
4660  }
4661  }
4662  }
4663 
4664  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4665  E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4666 
4668  Args, FnType, /*isChainCall=*/Chain);
4669 
4670  // C99 6.5.2.2p6:
4671  // If the expression that denotes the called function has a type
4672  // that does not include a prototype, [the default argument
4673  // promotions are performed]. If the number of arguments does not
4674  // equal the number of parameters, the behavior is undefined. If
4675  // the function is defined with a type that includes a prototype,
4676  // and either the prototype ends with an ellipsis (, ...) or the
4677  // types of the arguments after promotion are not compatible with
4678  // the types of the parameters, the behavior is undefined. If the
4679  // function is defined with a type that does not include a
4680  // prototype, and the types of the arguments after promotion are
4681  // not compatible with those of the parameters after promotion,
4682  // the behavior is undefined [except in some trivial cases].
4683  // That is, in the general case, we should assume that a call
4684  // through an unprototyped function type works like a *non-variadic*
4685  // call. The way we make this work is to cast to the exact type
4686  // of the promoted arguments.
4687  //
4688  // Chain calls use this same code path to add the invisible chain parameter
4689  // to the function type.
4690  if (isa<FunctionNoProtoType>(FnType) || Chain) {
4691  llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4692  CalleeTy = CalleeTy->getPointerTo();
4693 
4694  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4695  CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4696  Callee.setFunctionPointer(CalleePtr);
4697  }
4698 
4699  return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr, E->getExprLoc());
4700 }
4701 
4704  Address BaseAddr = Address::invalid();
4705  if (E->getOpcode() == BO_PtrMemI) {
4706  BaseAddr = EmitPointerWithAlignment(E->getLHS());
4707  } else {
4708  BaseAddr = EmitLValue(E->getLHS()).getAddress();
4709  }
4710 
4711  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4712 
4713  const MemberPointerType *MPT
4714  = E->getRHS()->getType()->getAs<MemberPointerType>();
4715 
4716  LValueBaseInfo BaseInfo;
4717  TBAAAccessInfo TBAAInfo;
4718  Address MemberAddr =
4719  EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
4720  &TBAAInfo);
4721 
4722  return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
4723 }
4724 
4725 /// Given the address of a temporary variable, produce an r-value of
4726 /// its type.
4728  QualType type,
4729  SourceLocation loc) {
4730  LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4731  switch (getEvaluationKind(type)) {
4732  case TEK_Complex:
4733  return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4734  case TEK_Aggregate:
4735  return lvalue.asAggregateRValue();
4736  case TEK_Scalar:
4737  return RValue::get(EmitLoadOfScalar(lvalue, loc));
4738  }
4739  llvm_unreachable("bad evaluation kind");
4740 }
4741 
4742 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4743  assert(Val->getType()->isFPOrFPVectorTy());
4744  if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4745  return;
4746 
4747  llvm::MDBuilder MDHelper(getLLVMContext());
4748  llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4749 
4750  cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4751 }
4752 
4753 namespace {
4754  struct LValueOrRValue {
4755  LValue LV;
4756  RValue RV;
4757  };
4758 }
4759 
4760 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4761  const PseudoObjectExpr *E,
4762  bool forLValue,
4763  AggValueSlot slot) {
4765 
4766  // Find the result expression, if any.
4767  const Expr *resultExpr = E->getResultExpr();
4768  LValueOrRValue result;
4769 
4771  i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4772  const Expr *semantic = *i;
4773 
4774  // If this semantic expression is an opaque value, bind it
4775  // to the result of its source expression.
4776  if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4777  // Skip unique OVEs.
4778  if (ov->isUnique()) {
4779  assert(ov != resultExpr &&
4780  "A unique OVE cannot be used as the result expression");
4781  continue;
4782  }
4783 
4784  // If this is the result expression, we may need to evaluate
4785  // directly into the slot.
4787  OVMA opaqueData;
4788  if (ov == resultExpr && ov->isRValue() && !forLValue &&
4790  CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4791  LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4793  opaqueData = OVMA::bind(CGF, ov, LV);
4794  resul