clang  10.0.0svn
CGExpr.cpp
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1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit Expr nodes as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CGCXXABI.h"
14 #include "CGCall.h"
15 #include "CGCleanup.h"
16 #include "CGDebugInfo.h"
17 #include "CGObjCRuntime.h"
18 #include "CGOpenMPRuntime.h"
19 #include "CGRecordLayout.h"
20 #include "CodeGenFunction.h"
21 #include "CodeGenModule.h"
22 #include "ConstantEmitter.h"
23 #include "TargetInfo.h"
24 #include "clang/AST/ASTContext.h"
25 #include "clang/AST/Attr.h"
26 #include "clang/AST/DeclObjC.h"
27 #include "clang/AST/NSAPI.h"
28 #include "clang/Basic/Builtins.h"
30 #include "llvm/ADT/Hashing.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/Intrinsics.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/MDBuilder.h"
36 #include "llvm/Support/ConvertUTF.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Transforms/Utils/SanitizerStats.h"
40 
41 #include <string>
42 
43 using namespace clang;
44 using namespace CodeGen;
45 
46 //===--------------------------------------------------------------------===//
47 // Miscellaneous Helper Methods
48 //===--------------------------------------------------------------------===//
49 
51  unsigned addressSpace =
52  cast<llvm::PointerType>(value->getType())->getAddressSpace();
53 
54  llvm::PointerType *destType = Int8PtrTy;
55  if (addressSpace)
56  destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
57 
58  if (value->getType() == destType) return value;
59  return Builder.CreateBitCast(value, destType);
60 }
61 
62 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
63 /// block.
65  CharUnits Align,
66  const Twine &Name,
67  llvm::Value *ArraySize) {
68  auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
69  Alloca->setAlignment(Align.getQuantity());
70  return Address(Alloca, Align);
71 }
72 
73 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
74 /// block. The alloca is casted to default address space if necessary.
76  const Twine &Name,
77  llvm::Value *ArraySize,
78  Address *AllocaAddr) {
79  auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
80  if (AllocaAddr)
81  *AllocaAddr = Alloca;
82  llvm::Value *V = Alloca.getPointer();
83  // Alloca always returns a pointer in alloca address space, which may
84  // be different from the type defined by the language. For example,
85  // in C++ the auto variables are in the default address space. Therefore
86  // cast alloca to the default address space when necessary.
88  auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
89  llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
90  // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
91  // otherwise alloca is inserted at the current insertion point of the
92  // builder.
93  if (!ArraySize)
94  Builder.SetInsertPoint(AllocaInsertPt);
97  Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
98  }
99 
100  return Address(V, Align);
101 }
102 
103 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
104 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
105 /// insertion point of the builder.
107  const Twine &Name,
108  llvm::Value *ArraySize) {
109  if (ArraySize)
110  return Builder.CreateAlloca(Ty, ArraySize, Name);
111  return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
112  ArraySize, Name, AllocaInsertPt);
113 }
114 
115 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
116 /// default alignment of the corresponding LLVM type, which is *not*
117 /// guaranteed to be related in any way to the expected alignment of
118 /// an AST type that might have been lowered to Ty.
120  const Twine &Name) {
121  CharUnits Align =
122  CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
123  return CreateTempAlloca(Ty, Align, Name);
124 }
125 
127  assert(isa<llvm::AllocaInst>(Var.getPointer()));
128  auto *Store = new llvm::StoreInst(Init, Var.getPointer());
129  Store->setAlignment(Var.getAlignment().getQuantity());
130  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
131  Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
132 }
133 
136  return CreateTempAlloca(ConvertType(Ty), Align, Name);
137 }
138 
140  Address *Alloca) {
141  // FIXME: Should we prefer the preferred type alignment here?
142  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
143 }
144 
146  const Twine &Name, Address *Alloca) {
147  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
148  /*ArraySize=*/nullptr, Alloca);
149 }
150 
152  const Twine &Name) {
153  return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
154 }
155 
157  const Twine &Name) {
158  return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
159  Name);
160 }
161 
162 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
163 /// expression and compare the result against zero, returning an Int1Ty value.
165  PGO.setCurrentStmt(E);
166  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
167  llvm::Value *MemPtr = EmitScalarExpr(E);
168  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
169  }
170 
171  QualType BoolTy = getContext().BoolTy;
172  SourceLocation Loc = E->getExprLoc();
173  if (!E->getType()->isAnyComplexType())
174  return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
175 
176  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
177  Loc);
178 }
179 
180 /// EmitIgnoredExpr - Emit code to compute the specified expression,
181 /// ignoring the result.
183  if (E->isRValue())
184  return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
185 
186  // Just emit it as an l-value and drop the result.
187  EmitLValue(E);
188 }
189 
190 /// EmitAnyExpr - Emit code to compute the specified expression which
191 /// can have any type. The result is returned as an RValue struct.
192 /// If this is an aggregate expression, AggSlot indicates where the
193 /// result should be returned.
195  AggValueSlot aggSlot,
196  bool ignoreResult) {
197  switch (getEvaluationKind(E->getType())) {
198  case TEK_Scalar:
199  return RValue::get(EmitScalarExpr(E, ignoreResult));
200  case TEK_Complex:
201  return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
202  case TEK_Aggregate:
203  if (!ignoreResult && aggSlot.isIgnored())
204  aggSlot = CreateAggTemp(E->getType(), "agg-temp");
205  EmitAggExpr(E, aggSlot);
206  return aggSlot.asRValue();
207  }
208  llvm_unreachable("bad evaluation kind");
209 }
210 
211 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
212 /// always be accessible even if no aggregate location is provided.
215 
217  AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
218  return EmitAnyExpr(E, AggSlot);
219 }
220 
221 /// EmitAnyExprToMem - Evaluate an expression into a given memory
222 /// location.
224  Address Location,
225  Qualifiers Quals,
226  bool IsInit) {
227  // FIXME: This function should take an LValue as an argument.
228  switch (getEvaluationKind(E->getType())) {
229  case TEK_Complex:
231  /*isInit*/ false);
232  return;
233 
234  case TEK_Aggregate: {
235  EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
238  AggValueSlot::IsAliased_t(!IsInit),
240  return;
241  }
242 
243  case TEK_Scalar: {
244  RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
245  LValue LV = MakeAddrLValue(Location, E->getType());
246  EmitStoreThroughLValue(RV, LV);
247  return;
248  }
249  }
250  llvm_unreachable("bad evaluation kind");
251 }
252 
253 static void
255  const Expr *E, Address ReferenceTemporary) {
256  // Objective-C++ ARC:
257  // If we are binding a reference to a temporary that has ownership, we
258  // need to perform retain/release operations on the temporary.
259  //
260  // FIXME: This should be looking at E, not M.
261  if (auto Lifetime = M->getType().getObjCLifetime()) {
262  switch (Lifetime) {
265  // Carry on to normal cleanup handling.
266  break;
267 
269  // Nothing to do; cleaned up by an autorelease pool.
270  return;
271 
274  switch (StorageDuration Duration = M->getStorageDuration()) {
275  case SD_Static:
276  // Note: we intentionally do not register a cleanup to release
277  // the object on program termination.
278  return;
279 
280  case SD_Thread:
281  // FIXME: We should probably register a cleanup in this case.
282  return;
283 
284  case SD_Automatic:
285  case SD_FullExpression:
288  if (Lifetime == Qualifiers::OCL_Strong) {
289  const ValueDecl *VD = M->getExtendingDecl();
290  bool Precise =
291  VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
292  CleanupKind = CGF.getARCCleanupKind();
293  Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
295  } else {
296  // __weak objects always get EH cleanups; otherwise, exceptions
297  // could cause really nasty crashes instead of mere leaks.
298  CleanupKind = NormalAndEHCleanup;
300  }
301  if (Duration == SD_FullExpression)
302  CGF.pushDestroy(CleanupKind, ReferenceTemporary,
303  M->getType(), *Destroy,
304  CleanupKind & EHCleanup);
305  else
306  CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
307  M->getType(),
308  *Destroy, CleanupKind & EHCleanup);
309  return;
310 
311  case SD_Dynamic:
312  llvm_unreachable("temporary cannot have dynamic storage duration");
313  }
314  llvm_unreachable("unknown storage duration");
315  }
316  }
317 
318  CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
319  if (const RecordType *RT =
321  // Get the destructor for the reference temporary.
322  auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
323  if (!ClassDecl->hasTrivialDestructor())
324  ReferenceTemporaryDtor = ClassDecl->getDestructor();
325  }
326 
327  if (!ReferenceTemporaryDtor)
328  return;
329 
330  // Call the destructor for the temporary.
331  switch (M->getStorageDuration()) {
332  case SD_Static:
333  case SD_Thread: {
334  llvm::FunctionCallee CleanupFn;
335  llvm::Constant *CleanupArg;
336  if (E->getType()->isArrayType()) {
337  CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
338  ReferenceTemporary, E->getType(),
340  dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
341  CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
342  } else {
343  CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
344  GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
345  CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
346  }
348  CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
349  break;
350  }
351 
352  case SD_FullExpression:
353  CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
355  CGF.getLangOpts().Exceptions);
356  break;
357 
358  case SD_Automatic:
360  ReferenceTemporary, E->getType(),
362  CGF.getLangOpts().Exceptions);
363  break;
364 
365  case SD_Dynamic:
366  llvm_unreachable("temporary cannot have dynamic storage duration");
367  }
368 }
369 
371  const MaterializeTemporaryExpr *M,
372  const Expr *Inner,
373  Address *Alloca = nullptr) {
374  auto &TCG = CGF.getTargetHooks();
375  switch (M->getStorageDuration()) {
376  case SD_FullExpression:
377  case SD_Automatic: {
378  // If we have a constant temporary array or record try to promote it into a
379  // constant global under the same rules a normal constant would've been
380  // promoted. This is easier on the optimizer and generally emits fewer
381  // instructions.
382  QualType Ty = Inner->getType();
383  if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
384  (Ty->isArrayType() || Ty->isRecordType()) &&
385  CGF.CGM.isTypeConstant(Ty, true))
386  if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
387  if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
388  auto AS = AddrSpace.getValue();
389  auto *GV = new llvm::GlobalVariable(
390  CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
391  llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
392  llvm::GlobalValue::NotThreadLocal,
394  CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
395  GV->setAlignment(alignment.getQuantity());
396  llvm::Constant *C = GV;
397  if (AS != LangAS::Default)
398  C = TCG.performAddrSpaceCast(
399  CGF.CGM, GV, AS, LangAS::Default,
400  GV->getValueType()->getPointerTo(
402  // FIXME: Should we put the new global into a COMDAT?
403  return Address(C, alignment);
404  }
405  }
406  return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
407  }
408  case SD_Thread:
409  case SD_Static:
410  return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
411 
412  case SD_Dynamic:
413  llvm_unreachable("temporary can't have dynamic storage duration");
414  }
415  llvm_unreachable("unknown storage duration");
416 }
417 
420  const Expr *E = M->GetTemporaryExpr();
421 
422  assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
423  !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
424  "Reference should never be pseudo-strong!");
425 
426  // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
427  // as that will cause the lifetime adjustment to be lost for ARC
428  auto ownership = M->getType().getObjCLifetime();
429  if (ownership != Qualifiers::OCL_None &&
430  ownership != Qualifiers::OCL_ExplicitNone) {
431  Address Object = createReferenceTemporary(*this, M, E);
432  if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
433  Object = Address(llvm::ConstantExpr::getBitCast(Var,
435  ->getPointerTo(Object.getAddressSpace())),
436  Object.getAlignment());
437 
438  // createReferenceTemporary will promote the temporary to a global with a
439  // constant initializer if it can. It can only do this to a value of
440  // ARC-manageable type if the value is global and therefore "immune" to
441  // ref-counting operations. Therefore we have no need to emit either a
442  // dynamic initialization or a cleanup and we can just return the address
443  // of the temporary.
444  if (Var->hasInitializer())
445  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
446 
447  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
448  }
449  LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
451 
452  switch (getEvaluationKind(E->getType())) {
453  default: llvm_unreachable("expected scalar or aggregate expression");
454  case TEK_Scalar:
455  EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
456  break;
457  case TEK_Aggregate: {
459  E->getType().getQualifiers(),
464  break;
465  }
466  }
467 
468  pushTemporaryCleanup(*this, M, E, Object);
469  return RefTempDst;
470  }
471 
474  E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
475 
476  for (const auto &Ignored : CommaLHSs)
477  EmitIgnoredExpr(Ignored);
478 
479  if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
480  if (opaque->getType()->isRecordType()) {
481  assert(Adjustments.empty());
482  return EmitOpaqueValueLValue(opaque);
483  }
484  }
485 
486  // Create and initialize the reference temporary.
487  Address Alloca = Address::invalid();
488  Address Object = createReferenceTemporary(*this, M, E, &Alloca);
489  if (auto *Var = dyn_cast<llvm::GlobalVariable>(
490  Object.getPointer()->stripPointerCasts())) {
491  Object = Address(llvm::ConstantExpr::getBitCast(
492  cast<llvm::Constant>(Object.getPointer()),
493  ConvertTypeForMem(E->getType())->getPointerTo()),
494  Object.getAlignment());
495  // If the temporary is a global and has a constant initializer or is a
496  // constant temporary that we promoted to a global, we may have already
497  // initialized it.
498  if (!Var->hasInitializer()) {
499  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
500  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
501  }
502  } else {
503  switch (M->getStorageDuration()) {
504  case SD_Automatic:
505  if (auto *Size = EmitLifetimeStart(
506  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
507  Alloca.getPointer())) {
508  pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
509  Alloca, Size);
510  }
511  break;
512 
513  case SD_FullExpression: {
514  if (!ShouldEmitLifetimeMarkers)
515  break;
516 
517  // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
518  // marker. Instead, start the lifetime of a conditional temporary earlier
519  // so that it's unconditional. Don't do this with sanitizers which need
520  // more precise lifetime marks.
521  ConditionalEvaluation *OldConditional = nullptr;
522  CGBuilderTy::InsertPoint OldIP;
524  !SanOpts.has(SanitizerKind::HWAddress) &&
525  !SanOpts.has(SanitizerKind::Memory) &&
526  !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
527  OldConditional = OutermostConditional;
528  OutermostConditional = nullptr;
529 
530  OldIP = Builder.saveIP();
531  llvm::BasicBlock *Block = OldConditional->getStartingBlock();
532  Builder.restoreIP(CGBuilderTy::InsertPoint(
533  Block, llvm::BasicBlock::iterator(Block->back())));
534  }
535 
536  if (auto *Size = EmitLifetimeStart(
537  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
538  Alloca.getPointer())) {
539  pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
540  Size);
541  }
542 
543  if (OldConditional) {
544  OutermostConditional = OldConditional;
545  Builder.restoreIP(OldIP);
546  }
547  break;
548  }
549 
550  default:
551  break;
552  }
553  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
554  }
555  pushTemporaryCleanup(*this, M, E, Object);
556 
557  // Perform derived-to-base casts and/or field accesses, to get from the
558  // temporary object we created (and, potentially, for which we extended
559  // the lifetime) to the subobject we're binding the reference to.
560  for (unsigned I = Adjustments.size(); I != 0; --I) {
561  SubobjectAdjustment &Adjustment = Adjustments[I-1];
562  switch (Adjustment.Kind) {
564  Object =
566  Adjustment.DerivedToBase.BasePath->path_begin(),
567  Adjustment.DerivedToBase.BasePath->path_end(),
568  /*NullCheckValue=*/ false, E->getExprLoc());
569  break;
570 
573  LV = EmitLValueForField(LV, Adjustment.Field);
574  assert(LV.isSimple() &&
575  "materialized temporary field is not a simple lvalue");
576  Object = LV.getAddress();
577  break;
578  }
579 
581  llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
582  Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
583  Adjustment.Ptr.MPT);
584  break;
585  }
586  }
587  }
588 
589  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
590 }
591 
592 RValue
594  // Emit the expression as an lvalue.
595  LValue LV = EmitLValue(E);
596  assert(LV.isSimple());
597  llvm::Value *Value = LV.getPointer();
598 
599  if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
600  // C++11 [dcl.ref]p5 (as amended by core issue 453):
601  // If a glvalue to which a reference is directly bound designates neither
602  // an existing object or function of an appropriate type nor a region of
603  // storage of suitable size and alignment to contain an object of the
604  // reference's type, the behavior is undefined.
605  QualType Ty = E->getType();
607  }
608 
609  return RValue::get(Value);
610 }
611 
612 
613 /// getAccessedFieldNo - Given an encoded value and a result number, return the
614 /// input field number being accessed.
616  const llvm::Constant *Elts) {
617  return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
618  ->getZExtValue();
619 }
620 
621 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
623  llvm::Value *High) {
624  llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
625  llvm::Value *K47 = Builder.getInt64(47);
626  llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
627  llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
628  llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
629  llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
630  return Builder.CreateMul(B1, KMul);
631 }
632 
634  return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
636 }
637 
639  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
640  return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
641  (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
642  TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
644 }
645 
648  SanOpts.has(SanitizerKind::Alignment) |
649  SanOpts.has(SanitizerKind::ObjectSize) |
650  SanOpts.has(SanitizerKind::Vptr);
651 }
652 
654  llvm::Value *Ptr, QualType Ty,
655  CharUnits Alignment,
656  SanitizerSet SkippedChecks,
657  llvm::Value *ArraySize) {
659  return;
660 
661  // Don't check pointers outside the default address space. The null check
662  // isn't correct, the object-size check isn't supported by LLVM, and we can't
663  // communicate the addresses to the runtime handler for the vptr check.
664  if (Ptr->getType()->getPointerAddressSpace())
665  return;
666 
667  // Don't check pointers to volatile data. The behavior here is implementation-
668  // defined.
669  if (Ty.isVolatileQualified())
670  return;
671 
672  SanitizerScope SanScope(this);
673 
675  llvm::BasicBlock *Done = nullptr;
676 
677  // Quickly determine whether we have a pointer to an alloca. It's possible
678  // to skip null checks, and some alignment checks, for these pointers. This
679  // can reduce compile-time significantly.
680  auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
681 
682  llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
683  llvm::Value *IsNonNull = nullptr;
684  bool IsGuaranteedNonNull =
685  SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
686  bool AllowNullPointers = isNullPointerAllowed(TCK);
687  if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
688  !IsGuaranteedNonNull) {
689  // The glvalue must not be an empty glvalue.
690  IsNonNull = Builder.CreateIsNotNull(Ptr);
691 
692  // The IR builder can constant-fold the null check if the pointer points to
693  // a constant.
694  IsGuaranteedNonNull = IsNonNull == True;
695 
696  // Skip the null check if the pointer is known to be non-null.
697  if (!IsGuaranteedNonNull) {
698  if (AllowNullPointers) {
699  // When performing pointer casts, it's OK if the value is null.
700  // Skip the remaining checks in that case.
701  Done = createBasicBlock("null");
702  llvm::BasicBlock *Rest = createBasicBlock("not.null");
703  Builder.CreateCondBr(IsNonNull, Rest, Done);
704  EmitBlock(Rest);
705  } else {
706  Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
707  }
708  }
709  }
710 
711  if (SanOpts.has(SanitizerKind::ObjectSize) &&
712  !SkippedChecks.has(SanitizerKind::ObjectSize) &&
713  !Ty->isIncompleteType()) {
714  uint64_t TySize = getContext().getTypeSizeInChars(Ty).getQuantity();
715  llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
716  if (ArraySize)
717  Size = Builder.CreateMul(Size, ArraySize);
718 
719  // Degenerate case: new X[0] does not need an objectsize check.
720  llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
721  if (!ConstantSize || !ConstantSize->isNullValue()) {
722  // The glvalue must refer to a large enough storage region.
723  // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
724  // to check this.
725  // FIXME: Get object address space
726  llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
727  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
728  llvm::Value *Min = Builder.getFalse();
729  llvm::Value *NullIsUnknown = Builder.getFalse();
730  llvm::Value *Dynamic = Builder.getFalse();
731  llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
732  llvm::Value *LargeEnough = Builder.CreateICmpUGE(
733  Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
734  Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
735  }
736  }
737 
738  uint64_t AlignVal = 0;
739  llvm::Value *PtrAsInt = nullptr;
740 
741  if (SanOpts.has(SanitizerKind::Alignment) &&
742  !SkippedChecks.has(SanitizerKind::Alignment)) {
743  AlignVal = Alignment.getQuantity();
744  if (!Ty->isIncompleteType() && !AlignVal)
745  AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
746 
747  // The glvalue must be suitably aligned.
748  if (AlignVal > 1 &&
749  (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
750  PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
751  llvm::Value *Align = Builder.CreateAnd(
752  PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
753  llvm::Value *Aligned =
754  Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
755  if (Aligned != True)
756  Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
757  }
758  }
759 
760  if (Checks.size() > 0) {
761  // Make sure we're not losing information. Alignment needs to be a power of
762  // 2
763  assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
764  llvm::Constant *StaticData[] = {
766  llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
767  llvm::ConstantInt::get(Int8Ty, TCK)};
768  EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
769  PtrAsInt ? PtrAsInt : Ptr);
770  }
771 
772  // If possible, check that the vptr indicates that there is a subobject of
773  // type Ty at offset zero within this object.
774  //
775  // C++11 [basic.life]p5,6:
776  // [For storage which does not refer to an object within its lifetime]
777  // The program has undefined behavior if:
778  // -- the [pointer or glvalue] is used to access a non-static data member
779  // or call a non-static member function
780  if (SanOpts.has(SanitizerKind::Vptr) &&
781  !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
782  // Ensure that the pointer is non-null before loading it. If there is no
783  // compile-time guarantee, reuse the run-time null check or emit a new one.
784  if (!IsGuaranteedNonNull) {
785  if (!IsNonNull)
786  IsNonNull = Builder.CreateIsNotNull(Ptr);
787  if (!Done)
788  Done = createBasicBlock("vptr.null");
789  llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
790  Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
791  EmitBlock(VptrNotNull);
792  }
793 
794  // Compute a hash of the mangled name of the type.
795  //
796  // FIXME: This is not guaranteed to be deterministic! Move to a
797  // fingerprinting mechanism once LLVM provides one. For the time
798  // being the implementation happens to be deterministic.
799  SmallString<64> MangledName;
800  llvm::raw_svector_ostream Out(MangledName);
802  Out);
803 
804  // Blacklist based on the mangled type.
806  SanitizerKind::Vptr, Out.str())) {
807  llvm::hash_code TypeHash = hash_value(Out.str());
808 
809  // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
810  llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
811  llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
812  Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
813  llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
814  llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
815 
816  llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
817  Hash = Builder.CreateTrunc(Hash, IntPtrTy);
818 
819  // Look the hash up in our cache.
820  const int CacheSize = 128;
821  llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
823  "__ubsan_vptr_type_cache");
824  llvm::Value *Slot = Builder.CreateAnd(Hash,
825  llvm::ConstantInt::get(IntPtrTy,
826  CacheSize-1));
827  llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
828  llvm::Value *CacheVal =
829  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
830  getPointerAlign());
831 
832  // If the hash isn't in the cache, call a runtime handler to perform the
833  // hard work of checking whether the vptr is for an object of the right
834  // type. This will either fill in the cache and return, or produce a
835  // diagnostic.
836  llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
837  llvm::Constant *StaticData[] = {
841  llvm::ConstantInt::get(Int8Ty, TCK)
842  };
843  llvm::Value *DynamicData[] = { Ptr, Hash };
844  EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
845  SanitizerHandler::DynamicTypeCacheMiss, StaticData,
846  DynamicData);
847  }
848  }
849 
850  if (Done) {
851  Builder.CreateBr(Done);
852  EmitBlock(Done);
853  }
854 }
855 
856 /// Determine whether this expression refers to a flexible array member in a
857 /// struct. We disable array bounds checks for such members.
858 static bool isFlexibleArrayMemberExpr(const Expr *E) {
859  // For compatibility with existing code, we treat arrays of length 0 or
860  // 1 as flexible array members.
861  const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
862  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
863  if (CAT->getSize().ugt(1))
864  return false;
865  } else if (!isa<IncompleteArrayType>(AT))
866  return false;
867 
868  E = E->IgnoreParens();
869 
870  // A flexible array member must be the last member in the class.
871  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
872  // FIXME: If the base type of the member expr is not FD->getParent(),
873  // this should not be treated as a flexible array member access.
874  if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
876  DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
877  return ++FI == FD->getParent()->field_end();
878  }
879  } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
880  return IRE->getDecl()->getNextIvar() == nullptr;
881  }
882 
883  return false;
884 }
885 
887  QualType EltTy) {
888  ASTContext &C = getContext();
889  uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
890  if (!EltSize)
891  return nullptr;
892 
893  auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
894  if (!ArrayDeclRef)
895  return nullptr;
896 
897  auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
898  if (!ParamDecl)
899  return nullptr;
900 
901  auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
902  if (!POSAttr)
903  return nullptr;
904 
905  // Don't load the size if it's a lower bound.
906  int POSType = POSAttr->getType();
907  if (POSType != 0 && POSType != 1)
908  return nullptr;
909 
910  // Find the implicit size parameter.
911  auto PassedSizeIt = SizeArguments.find(ParamDecl);
912  if (PassedSizeIt == SizeArguments.end())
913  return nullptr;
914 
915  const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
916  assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
917  Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
918  llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
919  C.getSizeType(), E->getExprLoc());
920  llvm::Value *SizeOfElement =
921  llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
922  return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
923 }
924 
925 /// If Base is known to point to the start of an array, return the length of
926 /// that array. Return 0 if the length cannot be determined.
928  CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
929  // For the vector indexing extension, the bound is the number of elements.
930  if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
931  IndexedType = Base->getType();
932  return CGF.Builder.getInt32(VT->getNumElements());
933  }
934 
935  Base = Base->IgnoreParens();
936 
937  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
938  if (CE->getCastKind() == CK_ArrayToPointerDecay &&
939  !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
940  IndexedType = CE->getSubExpr()->getType();
941  const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
942  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
943  return CGF.Builder.getInt(CAT->getSize());
944  else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
945  return CGF.getVLASize(VAT).NumElts;
946  // Ignore pass_object_size here. It's not applicable on decayed pointers.
947  }
948  }
949 
950  QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
951  if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
952  IndexedType = Base->getType();
953  return POS;
954  }
955 
956  return nullptr;
957 }
958 
960  llvm::Value *Index, QualType IndexType,
961  bool Accessed) {
962  assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
963  "should not be called unless adding bounds checks");
964  SanitizerScope SanScope(this);
965 
966  QualType IndexedType;
967  llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
968  if (!Bound)
969  return;
970 
971  bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
972  llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
973  llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
974 
975  llvm::Constant *StaticData[] = {
977  EmitCheckTypeDescriptor(IndexedType),
978  EmitCheckTypeDescriptor(IndexType)
979  };
980  llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
981  : Builder.CreateICmpULE(IndexVal, BoundVal);
982  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
983  SanitizerHandler::OutOfBounds, StaticData, Index);
984 }
985 
986 
989  bool isInc, bool isPre) {
990  ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
991 
992  llvm::Value *NextVal;
993  if (isa<llvm::IntegerType>(InVal.first->getType())) {
994  uint64_t AmountVal = isInc ? 1 : -1;
995  NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
996 
997  // Add the inc/dec to the real part.
998  NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
999  } else {
1000  QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
1001  llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1002  if (!isInc)
1003  FVal.changeSign();
1004  NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1005 
1006  // Add the inc/dec to the real part.
1007  NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1008  }
1009 
1010  ComplexPairTy IncVal(NextVal, InVal.second);
1011 
1012  // Store the updated result through the lvalue.
1013  EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1014 
1015  // If this is a postinc, return the value read from memory, otherwise use the
1016  // updated value.
1017  return isPre ? IncVal : InVal;
1018 }
1019 
1021  CodeGenFunction *CGF) {
1022  // Bind VLAs in the cast type.
1023  if (CGF && E->getType()->isVariablyModifiedType())
1024  CGF->EmitVariablyModifiedType(E->getType());
1025 
1026  if (CGDebugInfo *DI = getModuleDebugInfo())
1027  DI->EmitExplicitCastType(E->getType());
1028 }
1029 
1030 //===----------------------------------------------------------------------===//
1031 // LValue Expression Emission
1032 //===----------------------------------------------------------------------===//
1033 
1034 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1035 /// derive a more accurate bound on the alignment of the pointer.
1037  LValueBaseInfo *BaseInfo,
1038  TBAAAccessInfo *TBAAInfo) {
1039  // We allow this with ObjC object pointers because of fragile ABIs.
1040  assert(E->getType()->isPointerType() ||
1042  E = E->IgnoreParens();
1043 
1044  // Casts:
1045  if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1046  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1047  CGM.EmitExplicitCastExprType(ECE, this);
1048 
1049  switch (CE->getCastKind()) {
1050  // Non-converting casts (but not C's implicit conversion from void*).
1051  case CK_BitCast:
1052  case CK_NoOp:
1053  case CK_AddressSpaceConversion:
1054  if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1055  if (PtrTy->getPointeeType()->isVoidType())
1056  break;
1057 
1058  LValueBaseInfo InnerBaseInfo;
1059  TBAAAccessInfo InnerTBAAInfo;
1060  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1061  &InnerBaseInfo,
1062  &InnerTBAAInfo);
1063  if (BaseInfo) *BaseInfo = InnerBaseInfo;
1064  if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1065 
1066  if (isa<ExplicitCastExpr>(CE)) {
1067  LValueBaseInfo TargetTypeBaseInfo;
1068  TBAAAccessInfo TargetTypeTBAAInfo;
1069  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1070  &TargetTypeBaseInfo,
1071  &TargetTypeTBAAInfo);
1072  if (TBAAInfo)
1073  *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1074  TargetTypeTBAAInfo);
1075  // If the source l-value is opaque, honor the alignment of the
1076  // casted-to type.
1077  if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1078  if (BaseInfo)
1079  BaseInfo->mergeForCast(TargetTypeBaseInfo);
1080  Addr = Address(Addr.getPointer(), Align);
1081  }
1082  }
1083 
1084  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1085  CE->getCastKind() == CK_BitCast) {
1086  if (auto PT = E->getType()->getAs<PointerType>())
1087  EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1088  /*MayBeNull=*/true,
1090  CE->getBeginLoc());
1091  }
1092  return CE->getCastKind() != CK_AddressSpaceConversion
1093  ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1095  ConvertType(E->getType()));
1096  }
1097  break;
1098 
1099  // Array-to-pointer decay.
1100  case CK_ArrayToPointerDecay:
1101  return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1102 
1103  // Derived-to-base conversions.
1104  case CK_UncheckedDerivedToBase:
1105  case CK_DerivedToBase: {
1106  // TODO: Support accesses to members of base classes in TBAA. For now, we
1107  // conservatively pretend that the complete object is of the base class
1108  // type.
1109  if (TBAAInfo)
1110  *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1111  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1112  auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1113  return GetAddressOfBaseClass(Addr, Derived,
1114  CE->path_begin(), CE->path_end(),
1116  CE->getExprLoc());
1117  }
1118 
1119  // TODO: Is there any reason to treat base-to-derived conversions
1120  // specially?
1121  default:
1122  break;
1123  }
1124  }
1125 
1126  // Unary &.
1127  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1128  if (UO->getOpcode() == UO_AddrOf) {
1129  LValue LV = EmitLValue(UO->getSubExpr());
1130  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1131  if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1132  return LV.getAddress();
1133  }
1134  }
1135 
1136  // TODO: conditional operators, comma.
1137 
1138  // Otherwise, use the alignment of the type.
1139  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1140  TBAAInfo);
1141  return Address(EmitScalarExpr(E), Align);
1142 }
1143 
1145  if (Ty->isVoidType())
1146  return RValue::get(nullptr);
1147 
1148  switch (getEvaluationKind(Ty)) {
1149  case TEK_Complex: {
1150  llvm::Type *EltTy =
1152  llvm::Value *U = llvm::UndefValue::get(EltTy);
1153  return RValue::getComplex(std::make_pair(U, U));
1154  }
1155 
1156  // If this is a use of an undefined aggregate type, the aggregate must have an
1157  // identifiable address. Just because the contents of the value are undefined
1158  // doesn't mean that the address can't be taken and compared.
1159  case TEK_Aggregate: {
1160  Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1161  return RValue::getAggregate(DestPtr);
1162  }
1163 
1164  case TEK_Scalar:
1165  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1166  }
1167  llvm_unreachable("bad evaluation kind");
1168 }
1169 
1171  const char *Name) {
1172  ErrorUnsupported(E, Name);
1173  return GetUndefRValue(E->getType());
1174 }
1175 
1177  const char *Name) {
1178  ErrorUnsupported(E, Name);
1179  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1180  return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1181  E->getType());
1182 }
1183 
1185  const Expr *Base = Obj;
1186  while (!isa<CXXThisExpr>(Base)) {
1187  // The result of a dynamic_cast can be null.
1188  if (isa<CXXDynamicCastExpr>(Base))
1189  return false;
1190 
1191  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1192  Base = CE->getSubExpr();
1193  } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1194  Base = PE->getSubExpr();
1195  } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1196  if (UO->getOpcode() == UO_Extension)
1197  Base = UO->getSubExpr();
1198  else
1199  return false;
1200  } else {
1201  return false;
1202  }
1203  }
1204  return true;
1205 }
1206 
1208  LValue LV;
1209  if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1210  LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1211  else
1212  LV = EmitLValue(E);
1213  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1214  SanitizerSet SkippedChecks;
1215  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1216  bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1217  if (IsBaseCXXThis)
1218  SkippedChecks.set(SanitizerKind::Alignment, true);
1219  if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1220  SkippedChecks.set(SanitizerKind::Null, true);
1221  }
1222  EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1223  E->getType(), LV.getAlignment(), SkippedChecks);
1224  }
1225  return LV;
1226 }
1227 
1228 /// EmitLValue - Emit code to compute a designator that specifies the location
1229 /// of the expression.
1230 ///
1231 /// This can return one of two things: a simple address or a bitfield reference.
1232 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1233 /// an LLVM pointer type.
1234 ///
1235 /// If this returns a bitfield reference, nothing about the pointee type of the
1236 /// LLVM value is known: For example, it may not be a pointer to an integer.
1237 ///
1238 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1239 /// this method guarantees that the returned pointer type will point to an LLVM
1240 /// type of the same size of the lvalue's type. If the lvalue has a variable
1241 /// length type, this is not possible.
1242 ///
1244  ApplyDebugLocation DL(*this, E);
1245  switch (E->getStmtClass()) {
1246  default: return EmitUnsupportedLValue(E, "l-value expression");
1247 
1248  case Expr::ObjCPropertyRefExprClass:
1249  llvm_unreachable("cannot emit a property reference directly");
1250 
1251  case Expr::ObjCSelectorExprClass:
1252  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1253  case Expr::ObjCIsaExprClass:
1254  return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1255  case Expr::BinaryOperatorClass:
1256  return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1257  case Expr::CompoundAssignOperatorClass: {
1258  QualType Ty = E->getType();
1259  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1260  Ty = AT->getValueType();
1261  if (!Ty->isAnyComplexType())
1262  return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1263  return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1264  }
1265  case Expr::CallExprClass:
1266  case Expr::CXXMemberCallExprClass:
1267  case Expr::CXXOperatorCallExprClass:
1268  case Expr::UserDefinedLiteralClass:
1269  return EmitCallExprLValue(cast<CallExpr>(E));
1270  case Expr::VAArgExprClass:
1271  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1272  case Expr::DeclRefExprClass:
1273  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1274  case Expr::ConstantExprClass:
1275  return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1276  case Expr::ParenExprClass:
1277  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1278  case Expr::GenericSelectionExprClass:
1279  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1280  case Expr::PredefinedExprClass:
1281  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1282  case Expr::StringLiteralClass:
1283  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1284  case Expr::ObjCEncodeExprClass:
1285  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1286  case Expr::PseudoObjectExprClass:
1287  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1288  case Expr::InitListExprClass:
1289  return EmitInitListLValue(cast<InitListExpr>(E));
1290  case Expr::CXXTemporaryObjectExprClass:
1291  case Expr::CXXConstructExprClass:
1292  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1293  case Expr::CXXBindTemporaryExprClass:
1294  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1295  case Expr::CXXUuidofExprClass:
1296  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1297  case Expr::LambdaExprClass:
1298  return EmitAggExprToLValue(E);
1299 
1300  case Expr::ExprWithCleanupsClass: {
1301  const auto *cleanups = cast<ExprWithCleanups>(E);
1302  enterFullExpression(cleanups);
1303  RunCleanupsScope Scope(*this);
1304  LValue LV = EmitLValue(cleanups->getSubExpr());
1305  if (LV.isSimple()) {
1306  // Defend against branches out of gnu statement expressions surrounded by
1307  // cleanups.
1308  llvm::Value *V = LV.getPointer();
1309  Scope.ForceCleanup({&V});
1310  return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1311  getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1312  }
1313  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1314  // bitfield lvalue or some other non-simple lvalue?
1315  return LV;
1316  }
1317 
1318  case Expr::CXXDefaultArgExprClass: {
1319  auto *DAE = cast<CXXDefaultArgExpr>(E);
1320  CXXDefaultArgExprScope Scope(*this, DAE);
1321  return EmitLValue(DAE->getExpr());
1322  }
1323  case Expr::CXXDefaultInitExprClass: {
1324  auto *DIE = cast<CXXDefaultInitExpr>(E);
1325  CXXDefaultInitExprScope Scope(*this, DIE);
1326  return EmitLValue(DIE->getExpr());
1327  }
1328  case Expr::CXXTypeidExprClass:
1329  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1330 
1331  case Expr::ObjCMessageExprClass:
1332  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1333  case Expr::ObjCIvarRefExprClass:
1334  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1335  case Expr::StmtExprClass:
1336  return EmitStmtExprLValue(cast<StmtExpr>(E));
1337  case Expr::UnaryOperatorClass:
1338  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1339  case Expr::ArraySubscriptExprClass:
1340  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1341  case Expr::OMPArraySectionExprClass:
1342  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1343  case Expr::ExtVectorElementExprClass:
1344  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1345  case Expr::MemberExprClass:
1346  return EmitMemberExpr(cast<MemberExpr>(E));
1347  case Expr::CompoundLiteralExprClass:
1348  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1349  case Expr::ConditionalOperatorClass:
1350  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1351  case Expr::BinaryConditionalOperatorClass:
1352  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1353  case Expr::ChooseExprClass:
1354  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1355  case Expr::OpaqueValueExprClass:
1356  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1357  case Expr::SubstNonTypeTemplateParmExprClass:
1358  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1359  case Expr::ImplicitCastExprClass:
1360  case Expr::CStyleCastExprClass:
1361  case Expr::CXXFunctionalCastExprClass:
1362  case Expr::CXXStaticCastExprClass:
1363  case Expr::CXXDynamicCastExprClass:
1364  case Expr::CXXReinterpretCastExprClass:
1365  case Expr::CXXConstCastExprClass:
1366  case Expr::ObjCBridgedCastExprClass:
1367  return EmitCastLValue(cast<CastExpr>(E));
1368 
1369  case Expr::MaterializeTemporaryExprClass:
1370  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1371 
1372  case Expr::CoawaitExprClass:
1373  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1374  case Expr::CoyieldExprClass:
1375  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1376  }
1377 }
1378 
1379 /// Given an object of the given canonical type, can we safely copy a
1380 /// value out of it based on its initializer?
1382  assert(type.isCanonical());
1383  assert(!type->isReferenceType());
1384 
1385  // Must be const-qualified but non-volatile.
1386  Qualifiers qs = type.getLocalQualifiers();
1387  if (!qs.hasConst() || qs.hasVolatile()) return false;
1388 
1389  // Otherwise, all object types satisfy this except C++ classes with
1390  // mutable subobjects or non-trivial copy/destroy behavior.
1391  if (const auto *RT = dyn_cast<RecordType>(type))
1392  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1393  if (RD->hasMutableFields() || !RD->isTrivial())
1394  return false;
1395 
1396  return true;
1397 }
1398 
1399 /// Can we constant-emit a load of a reference to a variable of the
1400 /// given type? This is different from predicates like
1401 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1402 /// in situations that don't necessarily satisfy the language's rules
1403 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1404 /// to do this with const float variables even if those variables
1405 /// aren't marked 'constexpr'.
1411 };
1413  type = type.getCanonicalType();
1414  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1415  if (isConstantEmittableObjectType(ref->getPointeeType()))
1416  return CEK_AsValueOrReference;
1417  return CEK_AsReferenceOnly;
1418  }
1420  return CEK_AsValueOnly;
1421  return CEK_None;
1422 }
1423 
1424 /// Try to emit a reference to the given value without producing it as
1425 /// an l-value. This is just an optimization, but it avoids us needing
1426 /// to emit global copies of variables if they're named without triggering
1427 /// a formal use in a context where we can't emit a direct reference to them,
1428 /// for instance if a block or lambda or a member of a local class uses a
1429 /// const int variable or constexpr variable from an enclosing function.
1432  ValueDecl *value = refExpr->getDecl();
1433 
1434  // The value needs to be an enum constant or a constant variable.
1436  if (isa<ParmVarDecl>(value)) {
1437  CEK = CEK_None;
1438  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1439  CEK = checkVarTypeForConstantEmission(var->getType());
1440  } else if (isa<EnumConstantDecl>(value)) {
1441  CEK = CEK_AsValueOnly;
1442  } else {
1443  CEK = CEK_None;
1444  }
1445  if (CEK == CEK_None) return ConstantEmission();
1446 
1447  Expr::EvalResult result;
1448  bool resultIsReference;
1449  QualType resultType;
1450 
1451  // It's best to evaluate all the way as an r-value if that's permitted.
1452  if (CEK != CEK_AsReferenceOnly &&
1453  refExpr->EvaluateAsRValue(result, getContext())) {
1454  resultIsReference = false;
1455  resultType = refExpr->getType();
1456 
1457  // Otherwise, try to evaluate as an l-value.
1458  } else if (CEK != CEK_AsValueOnly &&
1459  refExpr->EvaluateAsLValue(result, getContext())) {
1460  resultIsReference = true;
1461  resultType = value->getType();
1462 
1463  // Failure.
1464  } else {
1465  return ConstantEmission();
1466  }
1467 
1468  // In any case, if the initializer has side-effects, abandon ship.
1469  if (result.HasSideEffects)
1470  return ConstantEmission();
1471 
1472  // Emit as a constant.
1473  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1474  result.Val, resultType);
1475 
1476  // Make sure we emit a debug reference to the global variable.
1477  // This should probably fire even for
1478  if (isa<VarDecl>(value)) {
1479  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1480  EmitDeclRefExprDbgValue(refExpr, result.Val);
1481  } else {
1482  assert(isa<EnumConstantDecl>(value));
1483  EmitDeclRefExprDbgValue(refExpr, result.Val);
1484  }
1485 
1486  // If we emitted a reference constant, we need to dereference that.
1487  if (resultIsReference)
1489 
1490  return ConstantEmission::forValue(C);
1491 }
1492 
1494  const MemberExpr *ME) {
1495  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1496  // Try to emit static variable member expressions as DREs.
1497  return DeclRefExpr::Create(
1499  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1500  ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1501  }
1502  return nullptr;
1503 }
1504 
1507  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1508  return tryEmitAsConstant(DRE);
1509  return ConstantEmission();
1510 }
1511 
1513  const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1514  assert(Constant && "not a constant");
1515  if (Constant.isReference())
1516  return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1517  E->getExprLoc())
1518  .getScalarVal();
1519  return Constant.getValue();
1520 }
1521 
1523  SourceLocation Loc) {
1524  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1525  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1526  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1527 }
1528 
1530  if (Ty->isBooleanType())
1531  return true;
1532 
1533  if (const EnumType *ET = Ty->getAs<EnumType>())
1534  return ET->getDecl()->getIntegerType()->isBooleanType();
1535 
1536  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1537  return hasBooleanRepresentation(AT->getValueType());
1538 
1539  return false;
1540 }
1541 
1543  llvm::APInt &Min, llvm::APInt &End,
1544  bool StrictEnums, bool IsBool) {
1545  const EnumType *ET = Ty->getAs<EnumType>();
1546  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1547  ET && !ET->getDecl()->isFixed();
1548  if (!IsBool && !IsRegularCPlusPlusEnum)
1549  return false;
1550 
1551  if (IsBool) {
1552  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1553  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1554  } else {
1555  const EnumDecl *ED = ET->getDecl();
1556  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1557  unsigned Bitwidth = LTy->getScalarSizeInBits();
1558  unsigned NumNegativeBits = ED->getNumNegativeBits();
1559  unsigned NumPositiveBits = ED->getNumPositiveBits();
1560 
1561  if (NumNegativeBits) {
1562  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1563  assert(NumBits <= Bitwidth);
1564  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1565  Min = -End;
1566  } else {
1567  assert(NumPositiveBits <= Bitwidth);
1568  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1569  Min = llvm::APInt(Bitwidth, 0);
1570  }
1571  }
1572  return true;
1573 }
1574 
1575 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1576  llvm::APInt Min, End;
1577  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1579  return nullptr;
1580 
1581  llvm::MDBuilder MDHelper(getLLVMContext());
1582  return MDHelper.createRange(Min, End);
1583 }
1584 
1586  SourceLocation Loc) {
1587  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1588  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1589  if (!HasBoolCheck && !HasEnumCheck)
1590  return false;
1591 
1592  bool IsBool = hasBooleanRepresentation(Ty) ||
1593  NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1594  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1595  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1596  if (!NeedsBoolCheck && !NeedsEnumCheck)
1597  return false;
1598 
1599  // Single-bit booleans don't need to be checked. Special-case this to avoid
1600  // a bit width mismatch when handling bitfield values. This is handled by
1601  // EmitFromMemory for the non-bitfield case.
1602  if (IsBool &&
1603  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1604  return false;
1605 
1606  llvm::APInt Min, End;
1607  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1608  return true;
1609 
1610  auto &Ctx = getLLVMContext();
1611  SanitizerScope SanScope(this);
1612  llvm::Value *Check;
1613  --End;
1614  if (!Min) {
1615  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1616  } else {
1617  llvm::Value *Upper =
1618  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1619  llvm::Value *Lower =
1620  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1621  Check = Builder.CreateAnd(Upper, Lower);
1622  }
1623  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1626  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1627  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1628  StaticArgs, EmitCheckValue(Value));
1629  return true;
1630 }
1631 
1633  QualType Ty,
1634  SourceLocation Loc,
1635  LValueBaseInfo BaseInfo,
1636  TBAAAccessInfo TBAAInfo,
1637  bool isNontemporal) {
1638  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1639  // For better performance, handle vector loads differently.
1640  if (Ty->isVectorType()) {
1641  const llvm::Type *EltTy = Addr.getElementType();
1642 
1643  const auto *VTy = cast<llvm::VectorType>(EltTy);
1644 
1645  // Handle vectors of size 3 like size 4 for better performance.
1646  if (VTy->getNumElements() == 3) {
1647 
1648  // Bitcast to vec4 type.
1649  llvm::VectorType *vec4Ty =
1650  llvm::VectorType::get(VTy->getElementType(), 4);
1651  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1652  // Now load value.
1653  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1654 
1655  // Shuffle vector to get vec3.
1656  V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1657  {0, 1, 2}, "extractVec");
1658  return EmitFromMemory(V, Ty);
1659  }
1660  }
1661  }
1662 
1663  // Atomic operations have to be done on integral types.
1664  LValue AtomicLValue =
1665  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1666  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1667  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1668  }
1669 
1670  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1671  if (isNontemporal) {
1672  llvm::MDNode *Node = llvm::MDNode::get(
1673  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1674  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1675  }
1676 
1677  CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1678 
1679  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1680  // In order to prevent the optimizer from throwing away the check, don't
1681  // attach range metadata to the load.
1682  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1683  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1684  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1685 
1686  return EmitFromMemory(Load, Ty);
1687 }
1688 
1690  // Bool has a different representation in memory than in registers.
1691  if (hasBooleanRepresentation(Ty)) {
1692  // This should really always be an i1, but sometimes it's already
1693  // an i8, and it's awkward to track those cases down.
1694  if (Value->getType()->isIntegerTy(1))
1695  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1696  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1697  "wrong value rep of bool");
1698  }
1699 
1700  return Value;
1701 }
1702 
1704  // Bool has a different representation in memory than in registers.
1705  if (hasBooleanRepresentation(Ty)) {
1706  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1707  "wrong value rep of bool");
1708  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1709  }
1710 
1711  return Value;
1712 }
1713 
1715  bool Volatile, QualType Ty,
1716  LValueBaseInfo BaseInfo,
1717  TBAAAccessInfo TBAAInfo,
1718  bool isInit, bool isNontemporal) {
1719  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1720  // Handle vectors differently to get better performance.
1721  if (Ty->isVectorType()) {
1722  llvm::Type *SrcTy = Value->getType();
1723  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1724  // Handle vec3 special.
1725  if (VecTy && VecTy->getNumElements() == 3) {
1726  // Our source is a vec3, do a shuffle vector to make it a vec4.
1727  llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1728  Builder.getInt32(2),
1729  llvm::UndefValue::get(Builder.getInt32Ty())};
1730  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1731  Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1732  MaskV, "extractVec");
1733  SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1734  }
1735  if (Addr.getElementType() != SrcTy) {
1736  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1737  }
1738  }
1739  }
1740 
1741  Value = EmitToMemory(Value, Ty);
1742 
1743  LValue AtomicLValue =
1744  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1745  if (Ty->isAtomicType() ||
1746  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1747  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1748  return;
1749  }
1750 
1751  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1752  if (isNontemporal) {
1753  llvm::MDNode *Node =
1754  llvm::MDNode::get(Store->getContext(),
1755  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1756  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1757  }
1758 
1759  CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1760 }
1761 
1763  bool isInit) {
1764  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1765  lvalue.getType(), lvalue.getBaseInfo(),
1766  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1767 }
1768 
1769 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1770 /// method emits the address of the lvalue, then loads the result as an rvalue,
1771 /// returning the rvalue.
1773  if (LV.isObjCWeak()) {
1774  // load of a __weak object.
1775  Address AddrWeakObj = LV.getAddress();
1777  AddrWeakObj));
1778  }
1780  // In MRC mode, we do a load+autorelease.
1781  if (!getLangOpts().ObjCAutoRefCount) {
1782  return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1783  }
1784 
1785  // In ARC mode, we load retained and then consume the value.
1787  Object = EmitObjCConsumeObject(LV.getType(), Object);
1788  return RValue::get(Object);
1789  }
1790 
1791  if (LV.isSimple()) {
1792  assert(!LV.getType()->isFunctionType());
1793 
1794  // Everything needs a load.
1795  return RValue::get(EmitLoadOfScalar(LV, Loc));
1796  }
1797 
1798  if (LV.isVectorElt()) {
1799  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1800  LV.isVolatileQualified());
1801  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1802  "vecext"));
1803  }
1804 
1805  // If this is a reference to a subset of the elements of a vector, either
1806  // shuffle the input or extract/insert them as appropriate.
1807  if (LV.isExtVectorElt())
1809 
1810  // Global Register variables always invoke intrinsics
1811  if (LV.isGlobalReg())
1812  return EmitLoadOfGlobalRegLValue(LV);
1813 
1814  assert(LV.isBitField() && "Unknown LValue type!");
1815  return EmitLoadOfBitfieldLValue(LV, Loc);
1816 }
1817 
1819  SourceLocation Loc) {
1820  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1821 
1822  // Get the output type.
1823  llvm::Type *ResLTy = ConvertType(LV.getType());
1824 
1825  Address Ptr = LV.getBitFieldAddress();
1826  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1827 
1828  if (Info.IsSigned) {
1829  assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1830  unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1831  if (HighBits)
1832  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1833  if (Info.Offset + HighBits)
1834  Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1835  } else {
1836  if (Info.Offset)
1837  Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1838  if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1839  Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1840  Info.Size),
1841  "bf.clear");
1842  }
1843  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1844  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1845  return RValue::get(Val);
1846 }
1847 
1848 // If this is a reference to a subset of the elements of a vector, create an
1849 // appropriate shufflevector.
1852  LV.isVolatileQualified());
1853 
1854  const llvm::Constant *Elts = LV.getExtVectorElts();
1855 
1856  // If the result of the expression is a non-vector type, we must be extracting
1857  // a single element. Just codegen as an extractelement.
1858  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1859  if (!ExprVT) {
1860  unsigned InIdx = getAccessedFieldNo(0, Elts);
1861  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1862  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1863  }
1864 
1865  // Always use shuffle vector to try to retain the original program structure
1866  unsigned NumResultElts = ExprVT->getNumElements();
1867 
1869  for (unsigned i = 0; i != NumResultElts; ++i)
1870  Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1871 
1872  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1873  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1874  MaskV);
1875  return RValue::get(Vec);
1876 }
1877 
1878 /// Generates lvalue for partial ext_vector access.
1880  Address VectorAddress = LV.getExtVectorAddress();
1881  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1882  QualType EQT = ExprVT->getElementType();
1883  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1884 
1885  Address CastToPointerElement =
1886  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1887  "conv.ptr.element");
1888 
1889  const llvm::Constant *Elts = LV.getExtVectorElts();
1890  unsigned ix = getAccessedFieldNo(0, Elts);
1891 
1892  Address VectorBasePtrPlusIx =
1893  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1894  "vector.elt");
1895 
1896  return VectorBasePtrPlusIx;
1897 }
1898 
1899 /// Load of global gamed gegisters are always calls to intrinsics.
1901  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1902  "Bad type for register variable");
1903  llvm::MDNode *RegName = cast<llvm::MDNode>(
1904  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1905 
1906  // We accept integer and pointer types only
1907  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1908  llvm::Type *Ty = OrigTy;
1909  if (OrigTy->isPointerTy())
1910  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1911  llvm::Type *Types[] = { Ty };
1912 
1913  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1914  llvm::Value *Call = Builder.CreateCall(
1915  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1916  if (OrigTy->isPointerTy())
1917  Call = Builder.CreateIntToPtr(Call, OrigTy);
1918  return RValue::get(Call);
1919 }
1920 
1921 
1922 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1923 /// lvalue, where both are guaranteed to the have the same type, and that type
1924 /// is 'Ty'.
1926  bool isInit) {
1927  if (!Dst.isSimple()) {
1928  if (Dst.isVectorElt()) {
1929  // Read/modify/write the vector, inserting the new element.
1931  Dst.isVolatileQualified());
1932  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1933  Dst.getVectorIdx(), "vecins");
1935  Dst.isVolatileQualified());
1936  return;
1937  }
1938 
1939  // If this is an update of extended vector elements, insert them as
1940  // appropriate.
1941  if (Dst.isExtVectorElt())
1943 
1944  if (Dst.isGlobalReg())
1945  return EmitStoreThroughGlobalRegLValue(Src, Dst);
1946 
1947  assert(Dst.isBitField() && "Unknown LValue type");
1948  return EmitStoreThroughBitfieldLValue(Src, Dst);
1949  }
1950 
1951  // There's special magic for assigning into an ARC-qualified l-value.
1952  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1953  switch (Lifetime) {
1954  case Qualifiers::OCL_None:
1955  llvm_unreachable("present but none");
1956 
1958  // nothing special
1959  break;
1960 
1962  if (isInit) {
1963  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1964  break;
1965  }
1966  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1967  return;
1968 
1969  case Qualifiers::OCL_Weak:
1970  if (isInit)
1971  // Initialize and then skip the primitive store.
1972  EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1973  else
1974  EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1975  return;
1976 
1979  Src.getScalarVal()));
1980  // fall into the normal path
1981  break;
1982  }
1983  }
1984 
1985  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1986  // load of a __weak object.
1987  Address LvalueDst = Dst.getAddress();
1988  llvm::Value *src = Src.getScalarVal();
1989  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1990  return;
1991  }
1992 
1993  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1994  // load of a __strong object.
1995  Address LvalueDst = Dst.getAddress();
1996  llvm::Value *src = Src.getScalarVal();
1997  if (Dst.isObjCIvar()) {
1998  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1999  llvm::Type *ResultType = IntPtrTy;
2001  llvm::Value *RHS = dst.getPointer();
2002  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2003  llvm::Value *LHS =
2004  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2005  "sub.ptr.lhs.cast");
2006  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2007  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2008  BytesBetween);
2009  } else if (Dst.isGlobalObjCRef()) {
2010  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2011  Dst.isThreadLocalRef());
2012  }
2013  else
2014  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2015  return;
2016  }
2017 
2018  assert(Src.isScalar() && "Can't emit an agg store with this method");
2019  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2020 }
2021 
2023  llvm::Value **Result) {
2024  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2025  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2026  Address Ptr = Dst.getBitFieldAddress();
2027 
2028  // Get the source value, truncated to the width of the bit-field.
2029  llvm::Value *SrcVal = Src.getScalarVal();
2030 
2031  // Cast the source to the storage type and shift it into place.
2032  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2033  /*isSigned=*/false);
2034  llvm::Value *MaskedVal = SrcVal;
2035 
2036  // See if there are other bits in the bitfield's storage we'll need to load
2037  // and mask together with source before storing.
2038  if (Info.StorageSize != Info.Size) {
2039  assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
2040  llvm::Value *Val =
2041  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2042 
2043  // Mask the source value as needed.
2044  if (!hasBooleanRepresentation(Dst.getType()))
2045  SrcVal = Builder.CreateAnd(SrcVal,
2046  llvm::APInt::getLowBitsSet(Info.StorageSize,
2047  Info.Size),
2048  "bf.value");
2049  MaskedVal = SrcVal;
2050  if (Info.Offset)
2051  SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
2052 
2053  // Mask out the original value.
2054  Val = Builder.CreateAnd(Val,
2055  ~llvm::APInt::getBitsSet(Info.StorageSize,
2056  Info.Offset,
2057  Info.Offset + Info.Size),
2058  "bf.clear");
2059 
2060  // Or together the unchanged values and the source value.
2061  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2062  } else {
2063  assert(Info.Offset == 0);
2064  }
2065 
2066  // Write the new value back out.
2067  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2068 
2069  // Return the new value of the bit-field, if requested.
2070  if (Result) {
2071  llvm::Value *ResultVal = MaskedVal;
2072 
2073  // Sign extend the value if needed.
2074  if (Info.IsSigned) {
2075  assert(Info.Size <= Info.StorageSize);
2076  unsigned HighBits = Info.StorageSize - Info.Size;
2077  if (HighBits) {
2078  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2079  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2080  }
2081  }
2082 
2083  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2084  "bf.result.cast");
2085  *Result = EmitFromMemory(ResultVal, Dst.getType());
2086  }
2087 }
2088 
2090  LValue Dst) {
2091  // This access turns into a read/modify/write of the vector. Load the input
2092  // value now.
2094  Dst.isVolatileQualified());
2095  const llvm::Constant *Elts = Dst.getExtVectorElts();
2096 
2097  llvm::Value *SrcVal = Src.getScalarVal();
2098 
2099  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2100  unsigned NumSrcElts = VTy->getNumElements();
2101  unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2102  if (NumDstElts == NumSrcElts) {
2103  // Use shuffle vector is the src and destination are the same number of
2104  // elements and restore the vector mask since it is on the side it will be
2105  // stored.
2106  SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2107  for (unsigned i = 0; i != NumSrcElts; ++i)
2108  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2109 
2110  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2111  Vec = Builder.CreateShuffleVector(SrcVal,
2112  llvm::UndefValue::get(Vec->getType()),
2113  MaskV);
2114  } else if (NumDstElts > NumSrcElts) {
2115  // Extended the source vector to the same length and then shuffle it
2116  // into the destination.
2117  // FIXME: since we're shuffling with undef, can we just use the indices
2118  // into that? This could be simpler.
2120  for (unsigned i = 0; i != NumSrcElts; ++i)
2121  ExtMask.push_back(Builder.getInt32(i));
2122  ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2123  llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2124  llvm::Value *ExtSrcVal =
2125  Builder.CreateShuffleVector(SrcVal,
2126  llvm::UndefValue::get(SrcVal->getType()),
2127  ExtMaskV);
2128  // build identity
2130  for (unsigned i = 0; i != NumDstElts; ++i)
2131  Mask.push_back(Builder.getInt32(i));
2132 
2133  // When the vector size is odd and .odd or .hi is used, the last element
2134  // of the Elts constant array will be one past the size of the vector.
2135  // Ignore the last element here, if it is greater than the mask size.
2136  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2137  NumSrcElts--;
2138 
2139  // modify when what gets shuffled in
2140  for (unsigned i = 0; i != NumSrcElts; ++i)
2141  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2142  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2143  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2144  } else {
2145  // We should never shorten the vector
2146  llvm_unreachable("unexpected shorten vector length");
2147  }
2148  } else {
2149  // If the Src is a scalar (not a vector) it must be updating one element.
2150  unsigned InIdx = getAccessedFieldNo(0, Elts);
2151  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2152  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2153  }
2154 
2156  Dst.isVolatileQualified());
2157 }
2158 
2159 /// Store of global named registers are always calls to intrinsics.
2161  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2162  "Bad type for register variable");
2163  llvm::MDNode *RegName = cast<llvm::MDNode>(
2164  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2165  assert(RegName && "Register LValue is not metadata");
2166 
2167  // We accept integer and pointer types only
2168  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2169  llvm::Type *Ty = OrigTy;
2170  if (OrigTy->isPointerTy())
2171  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2172  llvm::Type *Types[] = { Ty };
2173 
2174  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2175  llvm::Value *Value = Src.getScalarVal();
2176  if (OrigTy->isPointerTy())
2177  Value = Builder.CreatePtrToInt(Value, Ty);
2178  Builder.CreateCall(
2179  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2180 }
2181 
2182 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2183 // generating write-barries API. It is currently a global, ivar,
2184 // or neither.
2185 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2186  LValue &LV,
2187  bool IsMemberAccess=false) {
2188  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2189  return;
2190 
2191  if (isa<ObjCIvarRefExpr>(E)) {
2192  QualType ExpTy = E->getType();
2193  if (IsMemberAccess && ExpTy->isPointerType()) {
2194  // If ivar is a structure pointer, assigning to field of
2195  // this struct follows gcc's behavior and makes it a non-ivar
2196  // writer-barrier conservatively.
2197  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2198  if (ExpTy->isRecordType()) {
2199  LV.setObjCIvar(false);
2200  return;
2201  }
2202  }
2203  LV.setObjCIvar(true);
2204  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2205  LV.setBaseIvarExp(Exp->getBase());
2206  LV.setObjCArray(E->getType()->isArrayType());
2207  return;
2208  }
2209 
2210  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2211  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2212  if (VD->hasGlobalStorage()) {
2213  LV.setGlobalObjCRef(true);
2214  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2215  }
2216  }
2217  LV.setObjCArray(E->getType()->isArrayType());
2218  return;
2219  }
2220 
2221  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2222  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2223  return;
2224  }
2225 
2226  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2227  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2228  if (LV.isObjCIvar()) {
2229  // If cast is to a structure pointer, follow gcc's behavior and make it
2230  // a non-ivar write-barrier.
2231  QualType ExpTy = E->getType();
2232  if (ExpTy->isPointerType())
2233  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2234  if (ExpTy->isRecordType())
2235  LV.setObjCIvar(false);
2236  }
2237  return;
2238  }
2239 
2240  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2241  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2242  return;
2243  }
2244 
2245  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2246  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2247  return;
2248  }
2249 
2250  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2251  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2252  return;
2253  }
2254 
2255  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2256  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2257  return;
2258  }
2259 
2260  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2261  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2262  if (LV.isObjCIvar() && !LV.isObjCArray())
2263  // Using array syntax to assigning to what an ivar points to is not
2264  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2265  LV.setObjCIvar(false);
2266  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2267  // Using array syntax to assigning to what global points to is not
2268  // same as assigning to the global itself. {id *G;} G[i] = 0;
2269  LV.setGlobalObjCRef(false);
2270  return;
2271  }
2272 
2273  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2274  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2275  // We don't know if member is an 'ivar', but this flag is looked at
2276  // only in the context of LV.isObjCIvar().
2277  LV.setObjCArray(E->getType()->isArrayType());
2278  return;
2279  }
2280 }
2281 
2282 static llvm::Value *
2284  llvm::Value *V, llvm::Type *IRType,
2285  StringRef Name = StringRef()) {
2286  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2287  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2288 }
2289 
2291  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2292  llvm::Type *RealVarTy, SourceLocation Loc) {
2293  Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2294  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2295  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2296 }
2297 
2299  const VarDecl *VD, QualType T) {
2301  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2302  // Return an invalid address if variable is MT_To and unified
2303  // memory is not enabled. For all other cases: MT_Link and
2304  // MT_To with unified memory, return a valid address.
2305  if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2306  !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2307  return Address::invalid();
2308  assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2309  (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2310  CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2311  "Expected link clause OR to clause with unified memory enabled.");
2312  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2313  Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2314  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2315 }
2316 
2317 Address
2319  LValueBaseInfo *PointeeBaseInfo,
2320  TBAAAccessInfo *PointeeTBAAInfo) {
2321  llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2322  RefLVal.isVolatile());
2323  CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2324 
2326  PointeeBaseInfo, PointeeTBAAInfo,
2327  /* forPointeeType= */ true);
2328  return Address(Load, Align);
2329 }
2330 
2332  LValueBaseInfo PointeeBaseInfo;
2333  TBAAAccessInfo PointeeTBAAInfo;
2334  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2335  &PointeeTBAAInfo);
2336  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2337  PointeeBaseInfo, PointeeTBAAInfo);
2338 }
2339 
2341  const PointerType *PtrTy,
2342  LValueBaseInfo *BaseInfo,
2343  TBAAAccessInfo *TBAAInfo) {
2344  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2345  return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2346  BaseInfo, TBAAInfo,
2347  /*forPointeeType=*/true));
2348 }
2349 
2351  const PointerType *PtrTy) {
2352  LValueBaseInfo BaseInfo;
2353  TBAAAccessInfo TBAAInfo;
2354  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2355  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2356 }
2357 
2359  const Expr *E, const VarDecl *VD) {
2360  QualType T = E->getType();
2361 
2362  // If it's thread_local, emit a call to its wrapper function instead.
2363  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2365  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2366  // Check if the variable is marked as declare target with link clause in
2367  // device codegen.
2368  if (CGF.getLangOpts().OpenMPIsDevice) {
2369  Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2370  if (Addr.isValid())
2371  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2372  }
2373 
2374  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2375  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2376  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2377  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2378  Address Addr(V, Alignment);
2379  // Emit reference to the private copy of the variable if it is an OpenMP
2380  // threadprivate variable.
2381  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2382  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2383  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2384  E->getExprLoc());
2385  }
2386  LValue LV = VD->getType()->isReferenceType() ?
2387  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2389  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2390  setObjCGCLValueClass(CGF.getContext(), E, LV);
2391  return LV;
2392 }
2393 
2395  const FunctionDecl *FD) {
2396  if (FD->hasAttr<WeakRefAttr>()) {
2397  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2398  return aliasee.getPointer();
2399  }
2400 
2401  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2402  if (!FD->hasPrototype()) {
2403  if (const FunctionProtoType *Proto =
2404  FD->getType()->getAs<FunctionProtoType>()) {
2405  // Ugly case: for a K&R-style definition, the type of the definition
2406  // isn't the same as the type of a use. Correct for this with a
2407  // bitcast.
2408  QualType NoProtoType =
2409  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2410  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2411  V = llvm::ConstantExpr::getBitCast(V,
2412  CGM.getTypes().ConvertType(NoProtoType));
2413  }
2414  }
2415  return V;
2416 }
2417 
2419  const Expr *E, const FunctionDecl *FD) {
2420  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2421  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2422  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2424 }
2425 
2427  llvm::Value *ThisValue) {
2429  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2430  return CGF.EmitLValueForField(LV, FD);
2431 }
2432 
2433 /// Named Registers are named metadata pointing to the register name
2434 /// which will be read from/written to as an argument to the intrinsic
2435 /// @llvm.read/write_register.
2436 /// So far, only the name is being passed down, but other options such as
2437 /// register type, allocation type or even optimization options could be
2438 /// passed down via the metadata node.
2440  SmallString<64> Name("llvm.named.register.");
2441  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2442  assert(Asm->getLabel().size() < 64-Name.size() &&
2443  "Register name too big");
2444  Name.append(Asm->getLabel());
2445  llvm::NamedMDNode *M =
2446  CGM.getModule().getOrInsertNamedMetadata(Name);
2447  if (M->getNumOperands() == 0) {
2448  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2449  Asm->getLabel());
2450  llvm::Metadata *Ops[] = {Str};
2451  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2452  }
2453 
2454  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2455 
2456  llvm::Value *Ptr =
2457  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2458  return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2459 }
2460 
2461 /// Determine whether we can emit a reference to \p VD from the current
2462 /// context, despite not necessarily having seen an odr-use of the variable in
2463 /// this context.
2465  const DeclRefExpr *E,
2466  const VarDecl *VD,
2467  bool IsConstant) {
2468  // For a variable declared in an enclosing scope, do not emit a spurious
2469  // reference even if we have a capture, as that will emit an unwarranted
2470  // reference to our capture state, and will likely generate worse code than
2471  // emitting a local copy.
2473  return false;
2474 
2475  // For a local declaration declared in this function, we can always reference
2476  // it even if we don't have an odr-use.
2477  if (VD->hasLocalStorage()) {
2478  return VD->getDeclContext() ==
2479  dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2480  }
2481 
2482  // For a global declaration, we can emit a reference to it if we know
2483  // for sure that we are able to emit a definition of it.
2484  VD = VD->getDefinition(CGF.getContext());
2485  if (!VD)
2486  return false;
2487 
2488  // Don't emit a spurious reference if it might be to a variable that only
2489  // exists on a different device / target.
2490  // FIXME: This is unnecessarily broad. Check whether this would actually be a
2491  // cross-target reference.
2492  if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2493  CGF.getLangOpts().OpenCL) {
2494  return false;
2495  }
2496 
2497  // We can emit a spurious reference only if the linkage implies that we'll
2498  // be emitting a non-interposable symbol that will be retained until link
2499  // time.
2500  switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2502  case llvm::GlobalValue::LinkOnceODRLinkage:
2503  case llvm::GlobalValue::WeakODRLinkage:
2505  case llvm::GlobalValue::PrivateLinkage:
2506  return true;
2507  default:
2508  return false;
2509  }
2510 }
2511 
2513  const NamedDecl *ND = E->getDecl();
2514  QualType T = E->getType();
2515 
2516  assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2517  "should not emit an unevaluated operand");
2518 
2519  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2520  // Global Named registers access via intrinsics only
2521  if (VD->getStorageClass() == SC_Register &&
2522  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2523  return EmitGlobalNamedRegister(VD, CGM);
2524 
2525  // If this DeclRefExpr does not constitute an odr-use of the variable,
2526  // we're not permitted to emit a reference to it in general, and it might
2527  // not be captured if capture would be necessary for a use. Emit the
2528  // constant value directly instead.
2529  if (E->isNonOdrUse() == NOUR_Constant &&
2530  (VD->getType()->isReferenceType() ||
2531  !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2532  VD->getAnyInitializer(VD);
2533  llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2534  E->getLocation(), *VD->evaluateValue(), VD->getType());
2535  assert(Val && "failed to emit constant expression");
2536 
2537  Address Addr = Address::invalid();
2538  if (!VD->getType()->isReferenceType()) {
2539  // Spill the constant value to a global.
2540  Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2541  getContext().getDeclAlign(VD));
2542  llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
2543  auto *PTy = llvm::PointerType::get(
2544  VarTy, getContext().getTargetAddressSpace(VD->getType()));
2545  if (PTy != Addr.getType())
2546  Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy);
2547  } else {
2548  // Should we be using the alignment of the constant pointer we emitted?
2549  CharUnits Alignment =
2551  /* BaseInfo= */ nullptr,
2552  /* TBAAInfo= */ nullptr,
2553  /* forPointeeType= */ true);
2554  Addr = Address(Val, Alignment);
2555  }
2556  return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2557  }
2558 
2559  // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2560 
2561  // Check for captured variables.
2563  VD = VD->getCanonicalDecl();
2564  if (auto *FD = LambdaCaptureFields.lookup(VD))
2565  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2566  else if (CapturedStmtInfo) {
2567  auto I = LocalDeclMap.find(VD);
2568  if (I != LocalDeclMap.end()) {
2569  if (VD->getType()->isReferenceType())
2570  return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2572  return MakeAddrLValue(I->second, T);
2573  }
2574  LValue CapLVal =
2577  return MakeAddrLValue(
2578  Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2580  CapLVal.getTBAAInfo());
2581  }
2582 
2583  assert(isa<BlockDecl>(CurCodeDecl));
2584  Address addr = GetAddrOfBlockDecl(VD);
2585  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2586  }
2587  }
2588 
2589  // FIXME: We should be able to assert this for FunctionDecls as well!
2590  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2591  // those with a valid source location.
2592  assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2593  !E->getLocation().isValid()) &&
2594  "Should not use decl without marking it used!");
2595 
2596  if (ND->hasAttr<WeakRefAttr>()) {
2597  const auto *VD = cast<ValueDecl>(ND);
2598  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2599  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2600  }
2601 
2602  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2603  // Check if this is a global variable.
2604  if (VD->hasLinkage() || VD->isStaticDataMember())
2605  return EmitGlobalVarDeclLValue(*this, E, VD);
2606 
2607  Address addr = Address::invalid();
2608 
2609  // The variable should generally be present in the local decl map.
2610  auto iter = LocalDeclMap.find(VD);
2611  if (iter != LocalDeclMap.end()) {
2612  addr = iter->second;
2613 
2614  // Otherwise, it might be static local we haven't emitted yet for
2615  // some reason; most likely, because it's in an outer function.
2616  } else if (VD->isStaticLocal()) {
2618  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false)),
2619  getContext().getDeclAlign(VD));
2620 
2621  // No other cases for now.
2622  } else {
2623  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2624  }
2625 
2626 
2627  // Check for OpenMP threadprivate variables.
2628  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2629  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2631  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2632  E->getExprLoc());
2633  }
2634 
2635  // Drill into block byref variables.
2636  bool isBlockByref = VD->isEscapingByref();
2637  if (isBlockByref) {
2638  addr = emitBlockByrefAddress(addr, VD);
2639  }
2640 
2641  // Drill into reference types.
2642  LValue LV = VD->getType()->isReferenceType() ?
2645 
2646  bool isLocalStorage = VD->hasLocalStorage();
2647 
2648  bool NonGCable = isLocalStorage &&
2649  !VD->getType()->isReferenceType() &&
2650  !isBlockByref;
2651  if (NonGCable) {
2652  LV.getQuals().removeObjCGCAttr();
2653  LV.setNonGC(true);
2654  }
2655 
2656  bool isImpreciseLifetime =
2657  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2658  if (isImpreciseLifetime)
2660  setObjCGCLValueClass(getContext(), E, LV);
2661  return LV;
2662  }
2663 
2664  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2665  return EmitFunctionDeclLValue(*this, E, FD);
2666 
2667  // FIXME: While we're emitting a binding from an enclosing scope, all other
2668  // DeclRefExprs we see should be implicitly treated as if they also refer to
2669  // an enclosing scope.
2670  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2671  return EmitLValue(BD->getBinding());
2672 
2673  llvm_unreachable("Unhandled DeclRefExpr");
2674 }
2675 
2677  // __extension__ doesn't affect lvalue-ness.
2678  if (E->getOpcode() == UO_Extension)
2679  return EmitLValue(E->getSubExpr());
2680 
2682  switch (E->getOpcode()) {
2683  default: llvm_unreachable("Unknown unary operator lvalue!");
2684  case UO_Deref: {
2685  QualType T = E->getSubExpr()->getType()->getPointeeType();
2686  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2687 
2688  LValueBaseInfo BaseInfo;
2689  TBAAAccessInfo TBAAInfo;
2690  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2691  &TBAAInfo);
2692  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2693  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2694 
2695  // We should not generate __weak write barrier on indirect reference
2696  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2697  // But, we continue to generate __strong write barrier on indirect write
2698  // into a pointer to object.
2699  if (getLangOpts().ObjC &&
2700  getLangOpts().getGC() != LangOptions::NonGC &&
2701  LV.isObjCWeak())
2702  LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2703  return LV;
2704  }
2705  case UO_Real:
2706  case UO_Imag: {
2707  LValue LV = EmitLValue(E->getSubExpr());
2708  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2709 
2710  // __real is valid on scalars. This is a faster way of testing that.
2711  // __imag can only produce an rvalue on scalars.
2712  if (E->getOpcode() == UO_Real &&
2713  !LV.getAddress().getElementType()->isStructTy()) {
2714  assert(E->getSubExpr()->getType()->isArithmeticType());
2715  return LV;
2716  }
2717 
2718  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2719 
2720  Address Component =
2721  (E->getOpcode() == UO_Real
2724  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2725  CGM.getTBAAInfoForSubobject(LV, T));
2726  ElemLV.getQuals().addQualifiers(LV.getQuals());
2727  return ElemLV;
2728  }
2729  case UO_PreInc:
2730  case UO_PreDec: {
2731  LValue LV = EmitLValue(E->getSubExpr());
2732  bool isInc = E->getOpcode() == UO_PreInc;
2733 
2734  if (E->getType()->isAnyComplexType())
2735  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2736  else
2737  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2738  return LV;
2739  }
2740  }
2741 }
2742 
2746 }
2747 
2751 }
2752 
2754  auto SL = E->getFunctionName();
2755  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2756  StringRef FnName = CurFn->getName();
2757  if (FnName.startswith("\01"))
2758  FnName = FnName.substr(1);
2759  StringRef NameItems[] = {
2761  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2762  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2763  std::string Name = SL->getString();
2764  if (!Name.empty()) {
2765  unsigned Discriminator =
2766  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2767  if (Discriminator)
2768  Name += "_" + Twine(Discriminator + 1).str();
2769  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2770  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2771  } else {
2772  auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2773  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2774  }
2775  }
2776  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2777  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2778 }
2779 
2780 /// Emit a type description suitable for use by a runtime sanitizer library. The
2781 /// format of a type descriptor is
2782 ///
2783 /// \code
2784 /// { i16 TypeKind, i16 TypeInfo }
2785 /// \endcode
2786 ///
2787 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2788 /// integer, 1 for a floating point value, and -1 for anything else.
2790  // Only emit each type's descriptor once.
2791  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2792  return C;
2793 
2794  uint16_t TypeKind = -1;
2795  uint16_t TypeInfo = 0;
2796 
2797  if (T->isIntegerType()) {
2798  TypeKind = 0;
2799  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2800  (T->isSignedIntegerType() ? 1 : 0);
2801  } else if (T->isFloatingType()) {
2802  TypeKind = 1;
2803  TypeInfo = getContext().getTypeSize(T);
2804  }
2805 
2806  // Format the type name as if for a diagnostic, including quotes and
2807  // optionally an 'aka'.
2808  SmallString<32> Buffer;
2810  (intptr_t)T.getAsOpaquePtr(),
2811  StringRef(), StringRef(), None, Buffer,
2812  None);
2813 
2814  llvm::Constant *Components[] = {
2815  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2816  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2817  };
2818  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2819 
2820  auto *GV = new llvm::GlobalVariable(
2821  CGM.getModule(), Descriptor->getType(),
2822  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2823  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2825 
2826  // Remember the descriptor for this type.
2827  CGM.setTypeDescriptorInMap(T, GV);
2828 
2829  return GV;
2830 }
2831 
2833  llvm::Type *TargetTy = IntPtrTy;
2834 
2835  if (V->getType() == TargetTy)
2836  return V;
2837 
2838  // Floating-point types which fit into intptr_t are bitcast to integers
2839  // and then passed directly (after zero-extension, if necessary).
2840  if (V->getType()->isFloatingPointTy()) {
2841  unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2842  if (Bits <= TargetTy->getIntegerBitWidth())
2843  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2844  Bits));
2845  }
2846 
2847  // Integers which fit in intptr_t are zero-extended and passed directly.
2848  if (V->getType()->isIntegerTy() &&
2849  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2850  return Builder.CreateZExt(V, TargetTy);
2851 
2852  // Pointers are passed directly, everything else is passed by address.
2853  if (!V->getType()->isPointerTy()) {
2854  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2855  Builder.CreateStore(V, Ptr);
2856  V = Ptr.getPointer();
2857  }
2858  return Builder.CreatePtrToInt(V, TargetTy);
2859 }
2860 
2861 /// Emit a representation of a SourceLocation for passing to a handler
2862 /// in a sanitizer runtime library. The format for this data is:
2863 /// \code
2864 /// struct SourceLocation {
2865 /// const char *Filename;
2866 /// int32_t Line, Column;
2867 /// };
2868 /// \endcode
2869 /// For an invalid SourceLocation, the Filename pointer is null.
2871  llvm::Constant *Filename;
2872  int Line, Column;
2873 
2875  if (PLoc.isValid()) {
2876  StringRef FilenameString = PLoc.getFilename();
2877 
2878  int PathComponentsToStrip =
2879  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2880  if (PathComponentsToStrip < 0) {
2881  assert(PathComponentsToStrip != INT_MIN);
2882  int PathComponentsToKeep = -PathComponentsToStrip;
2883  auto I = llvm::sys::path::rbegin(FilenameString);
2884  auto E = llvm::sys::path::rend(FilenameString);
2885  while (I != E && --PathComponentsToKeep)
2886  ++I;
2887 
2888  FilenameString = FilenameString.substr(I - E);
2889  } else if (PathComponentsToStrip > 0) {
2890  auto I = llvm::sys::path::begin(FilenameString);
2891  auto E = llvm::sys::path::end(FilenameString);
2892  while (I != E && PathComponentsToStrip--)
2893  ++I;
2894 
2895  if (I != E)
2896  FilenameString =
2897  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2898  else
2899  FilenameString = llvm::sys::path::filename(FilenameString);
2900  }
2901 
2902  auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2904  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2905  Filename = FilenameGV.getPointer();
2906  Line = PLoc.getLine();
2907  Column = PLoc.getColumn();
2908  } else {
2909  Filename = llvm::Constant::getNullValue(Int8PtrTy);
2910  Line = Column = 0;
2911  }
2912 
2913  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2914  Builder.getInt32(Column)};
2915 
2916  return llvm::ConstantStruct::getAnon(Data);
2917 }
2918 
2919 namespace {
2920 /// Specify under what conditions this check can be recovered
2922  /// Always terminate program execution if this check fails.
2923  Unrecoverable,
2924  /// Check supports recovering, runtime has both fatal (noreturn) and
2925  /// non-fatal handlers for this check.
2926  Recoverable,
2927  /// Runtime conditionally aborts, always need to support recovery.
2929 };
2930 }
2931 
2933  assert(Kind.countPopulation() == 1);
2934  if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
2936  else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
2938  else
2939  return CheckRecoverableKind::Recoverable;
2940 }
2941 
2942 namespace {
2943 struct SanitizerHandlerInfo {
2944  char const *const Name;
2945  unsigned Version;
2946 };
2947 }
2948 
2949 const SanitizerHandlerInfo SanitizerHandlers[] = {
2950 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2952 #undef SANITIZER_CHECK
2953 };
2954 
2956  llvm::FunctionType *FnType,
2957  ArrayRef<llvm::Value *> FnArgs,
2958  SanitizerHandler CheckHandler,
2959  CheckRecoverableKind RecoverKind, bool IsFatal,
2960  llvm::BasicBlock *ContBB) {
2961  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2963  if (!CGF.Builder.getCurrentDebugLocation()) {
2964  // Ensure that the call has at least an artificial debug location.
2965  DL.emplace(CGF, SourceLocation());
2966  }
2967  bool NeedsAbortSuffix =
2968  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2969  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2970  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2971  const StringRef CheckName = CheckInfo.Name;
2972  std::string FnName = "__ubsan_handle_" + CheckName.str();
2973  if (CheckInfo.Version && !MinimalRuntime)
2974  FnName += "_v" + llvm::utostr(CheckInfo.Version);
2975  if (MinimalRuntime)
2976  FnName += "_minimal";
2977  if (NeedsAbortSuffix)
2978  FnName += "_abort";
2979  bool MayReturn =
2980  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2981 
2982  llvm::AttrBuilder B;
2983  if (!MayReturn) {
2984  B.addAttribute(llvm::Attribute::NoReturn)
2985  .addAttribute(llvm::Attribute::NoUnwind);
2986  }
2987  B.addAttribute(llvm::Attribute::UWTable);
2988 
2989  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
2990  FnType, FnName,
2991  llvm::AttributeList::get(CGF.getLLVMContext(),
2992  llvm::AttributeList::FunctionIndex, B),
2993  /*Local=*/true);
2994  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2995  if (!MayReturn) {
2996  HandlerCall->setDoesNotReturn();
2997  CGF.Builder.CreateUnreachable();
2998  } else {
2999  CGF.Builder.CreateBr(ContBB);
3000  }
3001 }
3002 
3004  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3005  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3006  ArrayRef<llvm::Value *> DynamicArgs) {
3007  assert(IsSanitizerScope);
3008  assert(Checked.size() > 0);
3009  assert(CheckHandler >= 0 &&
3010  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3011  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3012 
3013  llvm::Value *FatalCond = nullptr;
3014  llvm::Value *RecoverableCond = nullptr;
3015  llvm::Value *TrapCond = nullptr;
3016  for (int i = 0, n = Checked.size(); i < n; ++i) {
3017  llvm::Value *Check = Checked[i].first;
3018  // -fsanitize-trap= overrides -fsanitize-recover=.
3019  llvm::Value *&Cond =
3020  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3021  ? TrapCond
3022  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3023  ? RecoverableCond
3024  : FatalCond;
3025  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3026  }
3027 
3028  if (TrapCond)
3029  EmitTrapCheck(TrapCond);
3030  if (!FatalCond && !RecoverableCond)
3031  return;
3032 
3033  llvm::Value *JointCond;
3034  if (FatalCond && RecoverableCond)
3035  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3036  else
3037  JointCond = FatalCond ? FatalCond : RecoverableCond;
3038  assert(JointCond);
3039 
3040  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3041  assert(SanOpts.has(Checked[0].second));
3042 #ifndef NDEBUG
3043  for (int i = 1, n = Checked.size(); i < n; ++i) {
3044  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3045  "All recoverable kinds in a single check must be same!");
3046  assert(SanOpts.has(Checked[i].second));
3047  }
3048 #endif
3049 
3050  llvm::BasicBlock *Cont = createBasicBlock("cont");
3051  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3052  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3053  // Give hint that we very much don't expect to execute the handler
3054  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3055  llvm::MDBuilder MDHelper(getLLVMContext());
3056  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3057  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3058  EmitBlock(Handlers);
3059 
3060  // Handler functions take an i8* pointing to the (handler-specific) static
3061  // information block, followed by a sequence of intptr_t arguments
3062  // representing operand values.
3065  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3066  Args.reserve(DynamicArgs.size() + 1);
3067  ArgTypes.reserve(DynamicArgs.size() + 1);
3068 
3069  // Emit handler arguments and create handler function type.
3070  if (!StaticArgs.empty()) {
3071  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3072  auto *InfoPtr =
3073  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3074  llvm::GlobalVariable::PrivateLinkage, Info);
3075  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3077  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3078  ArgTypes.push_back(Int8PtrTy);
3079  }
3080 
3081  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3082  Args.push_back(EmitCheckValue(DynamicArgs[i]));
3083  ArgTypes.push_back(IntPtrTy);
3084  }
3085  }
3086 
3087  llvm::FunctionType *FnType =
3088  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3089 
3090  if (!FatalCond || !RecoverableCond) {
3091  // Simple case: we need to generate a single handler call, either
3092  // fatal, or non-fatal.
3093  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3094  (FatalCond != nullptr), Cont);
3095  } else {
3096  // Emit two handler calls: first one for set of unrecoverable checks,
3097  // another one for recoverable.
3098  llvm::BasicBlock *NonFatalHandlerBB =
3099  createBasicBlock("non_fatal." + CheckName);
3100  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3101  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3102  EmitBlock(FatalHandlerBB);
3103  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3104  NonFatalHandlerBB);
3105  EmitBlock(NonFatalHandlerBB);
3106  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3107  Cont);
3108  }
3109 
3110  EmitBlock(Cont);
3111 }
3112 
3114  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3115  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3116  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3117 
3118  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3119  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3120 
3121  llvm::MDBuilder MDHelper(getLLVMContext());
3122  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3123  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3124 
3125  EmitBlock(CheckBB);
3126 
3127  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3128 
3129  llvm::CallInst *CheckCall;
3130  llvm::FunctionCallee SlowPathFn;
3131  if (WithDiag) {
3132  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3133  auto *InfoPtr =
3134  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3135  llvm::GlobalVariable::PrivateLinkage, Info);
3136  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3138 
3139  SlowPathFn = CGM.getModule().getOrInsertFunction(
3140  "__cfi_slowpath_diag",
3141  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3142  false));
3143  CheckCall = Builder.CreateCall(
3144  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3145  } else {
3146  SlowPathFn = CGM.getModule().getOrInsertFunction(
3147  "__cfi_slowpath",
3148  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3149  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3150  }
3151 
3152  CGM.setDSOLocal(
3153  cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3154  CheckCall->setDoesNotThrow();
3155 
3156  EmitBlock(Cont);
3157 }
3158 
3159 // Emit a stub for __cfi_check function so that the linker knows about this
3160 // symbol in LTO mode.
3162  llvm::Module *M = &CGM.getModule();
3163  auto &Ctx = M->getContext();
3164  llvm::Function *F = llvm::Function::Create(
3165  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3166  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3167  CGM.setDSOLocal(F);
3168  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3169  // FIXME: consider emitting an intrinsic call like
3170  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3171  // which can be lowered in CrossDSOCFI pass to the actual contents of
3172  // __cfi_check. This would allow inlining of __cfi_check calls.
3174  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3175  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3176 }
3177 
3178 // This function is basically a switch over the CFI failure kind, which is
3179 // extracted from CFICheckFailData (1st function argument). Each case is either
3180 // llvm.trap or a call to one of the two runtime handlers, based on
3181 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3182 // failure kind) traps, but this should really never happen. CFICheckFailData
3183 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3184 // check kind; in this case __cfi_check_fail traps as well.
3186  SanitizerScope SanScope(this);
3187  FunctionArgList Args;
3192  Args.push_back(&ArgData);
3193  Args.push_back(&ArgAddr);
3194 
3195  const CGFunctionInfo &FI =
3197 
3198  llvm::Function *F = llvm::Function::Create(
3199  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3200  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3201  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3202 
3203  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3204  SourceLocation());
3205 
3206  // This function should not be affected by blacklist. This function does
3207  // not have a source location, but "src:*" would still apply. Revert any
3208  // changes to SanOpts made in StartFunction.
3210 
3211  llvm::Value *Data =
3212  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3213  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3214  llvm::Value *Addr =
3215  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3216  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3217 
3218  // Data == nullptr means the calling module has trap behaviour for this check.
3219  llvm::Value *DataIsNotNullPtr =
3220  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3221  EmitTrapCheck(DataIsNotNullPtr);
3222 
3223  llvm::StructType *SourceLocationTy =
3224  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3225  llvm::StructType *CfiCheckFailDataTy =
3226  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3227 
3228  llvm::Value *V = Builder.CreateConstGEP2_32(
3229  CfiCheckFailDataTy,
3230  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3231  0);
3232  Address CheckKindAddr(V, getIntAlign());
3233  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3234 
3235  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3236  CGM.getLLVMContext(),
3237  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3238  llvm::Value *ValidVtable = Builder.CreateZExt(
3239  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3240  {Addr, AllVtables}),
3241  IntPtrTy);
3242 
3243  const std::pair<int, SanitizerMask> CheckKinds[] = {
3244  {CFITCK_VCall, SanitizerKind::CFIVCall},
3245  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3246  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3247  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3248  {CFITCK_ICall, SanitizerKind::CFIICall}};
3249 
3251  for (auto CheckKindMaskPair : CheckKinds) {
3252  int Kind = CheckKindMaskPair.first;
3253  SanitizerMask Mask = CheckKindMaskPair.second;
3254  llvm::Value *Cond =
3255  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3256  if (CGM.getLangOpts().Sanitize.has(Mask))
3257  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3258  {Data, Addr, ValidVtable});
3259  else
3260  EmitTrapCheck(Cond);
3261  }
3262 
3263  FinishFunction();
3264  // The only reference to this function will be created during LTO link.
3265  // Make sure it survives until then.
3266  CGM.addUsedGlobal(F);
3267 }
3268 
3270  if (SanOpts.has(SanitizerKind::Unreachable)) {
3271  SanitizerScope SanScope(this);
3272  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3273  SanitizerKind::Unreachable),
3274  SanitizerHandler::BuiltinUnreachable,
3275  EmitCheckSourceLocation(Loc), None);
3276  }
3277  Builder.CreateUnreachable();
3278 }
3279 
3281  llvm::BasicBlock *Cont = createBasicBlock("cont");
3282 
3283  // If we're optimizing, collapse all calls to trap down to just one per
3284  // function to save on code size.
3285  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3286  TrapBB = createBasicBlock("trap");
3287  Builder.CreateCondBr(Checked, Cont, TrapBB);
3288  EmitBlock(TrapBB);
3289  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3290  TrapCall->setDoesNotReturn();
3291  TrapCall->setDoesNotThrow();
3292  Builder.CreateUnreachable();
3293  } else {
3294  Builder.CreateCondBr(Checked, Cont, TrapBB);
3295  }
3296 
3297  EmitBlock(Cont);
3298 }
3299 
3301  llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3302 
3303  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3304  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3306  TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3307  }
3308 
3309  return TrapCall;
3310 }
3311 
3313  LValueBaseInfo *BaseInfo,
3314  TBAAAccessInfo *TBAAInfo) {
3315  assert(E->getType()->isArrayType() &&
3316  "Array to pointer decay must have array source type!");
3317 
3318  // Expressions of array type can't be bitfields or vector elements.
3319  LValue LV = EmitLValue(E);
3320  Address Addr = LV.getAddress();
3321 
3322  // If the array type was an incomplete type, we need to make sure
3323  // the decay ends up being the right type.
3324  llvm::Type *NewTy = ConvertType(E->getType());
3325  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3326 
3327  // Note that VLA pointers are always decayed, so we don't need to do
3328  // anything here.
3329  if (!E->getType()->isVariableArrayType()) {
3330  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3331  "Expected pointer to array");
3332  Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3333  }
3334 
3335  // The result of this decay conversion points to an array element within the
3336  // base lvalue. However, since TBAA currently does not support representing
3337  // accesses to elements of member arrays, we conservatively represent accesses
3338  // to the pointee object as if it had no any base lvalue specified.
3339  // TODO: Support TBAA for member arrays.
3341  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3342  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3343 
3344  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3345 }
3346 
3347 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3348 /// array to pointer, return the array subexpression.
3349 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3350  // If this isn't just an array->pointer decay, bail out.
3351  const auto *CE = dyn_cast<CastExpr>(E);
3352  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3353  return nullptr;
3354 
3355  // If this is a decay from variable width array, bail out.
3356  const Expr *SubExpr = CE->getSubExpr();
3357  if (SubExpr->getType()->isVariableArrayType())
3358  return nullptr;
3359 
3360  return SubExpr;
3361 }
3362 
3364  llvm::Value *ptr,
3365  ArrayRef<llvm::Value*> indices,
3366  bool inbounds,
3367  bool signedIndices,
3368  SourceLocation loc,
3369  const llvm::Twine &name = "arrayidx") {
3370  if (inbounds) {
3371  return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3373  name);
3374  } else {
3375  return CGF.Builder.CreateGEP(ptr, indices, name);
3376  }
3377 }
3378 
3380  llvm::Value *idx,
3381  CharUnits eltSize) {
3382  // If we have a constant index, we can use the exact offset of the
3383  // element we're accessing.
3384  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3385  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3386  return arrayAlign.alignmentAtOffset(offset);
3387 
3388  // Otherwise, use the worst-case alignment for any element.
3389  } else {
3390  return arrayAlign.alignmentOfArrayElement(eltSize);
3391  }
3392 }
3393 
3395  const VariableArrayType *vla) {
3396  QualType eltType;
3397  do {
3398  eltType = vla->getElementType();
3399  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3400  return eltType;
3401 }
3402 
3404  ArrayRef<llvm::Value *> indices,
3405  QualType eltType, bool inbounds,
3406  bool signedIndices, SourceLocation loc,
3407  QualType *arrayType = nullptr,
3408  const llvm::Twine &name = "arrayidx") {
3409  // All the indices except that last must be zero.
3410 #ifndef NDEBUG
3411  for (auto idx : indices.drop_back())
3412  assert(isa<llvm::ConstantInt>(idx) &&
3413  cast<llvm::ConstantInt>(idx)->isZero());
3414 #endif
3415 
3416  // Determine the element size of the statically-sized base. This is
3417  // the thing that the indices are expressed in terms of.
3418  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3419  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3420  }
3421 
3422  // We can use that to compute the best alignment of the element.
3423  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3424  CharUnits eltAlign =
3425  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3426 
3427  llvm::Value *eltPtr;
3428  auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3429  if (!CGF.IsInPreservedAIRegion || !LastIndex) {
3430  eltPtr = emitArraySubscriptGEP(
3431  CGF, addr.getPointer(), indices, inbounds, signedIndices,
3432  loc, name);
3433  } else {
3434  // Remember the original array subscript for bpf target
3435  unsigned idx = LastIndex->getZExtValue();
3436  llvm::DIType *DbgInfo = nullptr;
3437  if (arrayType)
3438  DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
3439  eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getPointer(),
3440  indices.size() - 1,
3441  idx, DbgInfo);
3442  }
3443 
3444  return Address(eltPtr, eltAlign);
3445 }
3446 
3448  bool Accessed) {
3449  // The index must always be an integer, which is not an aggregate. Emit it
3450  // in lexical order (this complexity is, sadly, required by C++17).
3451  llvm::Value *IdxPre =
3452  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3453  bool SignedIndices = false;
3454  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3455  auto *Idx = IdxPre;
3456  if (E->getLHS() != E->getIdx()) {
3457  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3458  Idx = EmitScalarExpr(E->getIdx());
3459  }
3460 
3461  QualType IdxTy = E->getIdx()->getType();
3462  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3463  SignedIndices |= IdxSigned;
3464 
3465  if (SanOpts.has(SanitizerKind::ArrayBounds))
3466  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3467 
3468  // Extend or truncate the index type to 32 or 64-bits.
3469  if (Promote && Idx->getType() != IntPtrTy)
3470  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3471 
3472  return Idx;
3473  };
3474  IdxPre = nullptr;
3475 
3476  // If the base is a vector type, then we are forming a vector element lvalue
3477  // with this subscript.
3478  if (E->getBase()->getType()->isVectorType() &&
3479  !isa<ExtVectorElementExpr>(E->getBase())) {
3480  // Emit the vector as an lvalue to get its address.
3481  LValue LHS = EmitLValue(E->getBase());
3482  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3483  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3484  return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3485  LHS.getBaseInfo(), TBAAAccessInfo());
3486  }
3487 
3488  // All the other cases basically behave like simple offsetting.
3489 
3490  // Handle the extvector case we ignored above.
3491  if (isa<ExtVectorElementExpr>(E->getBase())) {
3492  LValue LV = EmitLValue(E->getBase());
3493  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3495 
3496  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3497  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3498  SignedIndices, E->getExprLoc());
3499  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3500  CGM.getTBAAInfoForSubobject(LV, EltType));
3501  }
3502 
3503  LValueBaseInfo EltBaseInfo;
3504  TBAAAccessInfo EltTBAAInfo;
3505  Address Addr = Address::invalid();
3506  if (const VariableArrayType *vla =
3507  getContext().getAsVariableArrayType(E->getType())) {
3508  // The base must be a pointer, which is not an aggregate. Emit
3509  // it. It needs to be emitted first in case it's what captures
3510  // the VLA bounds.
3511  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3512  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3513 
3514  // The element count here is the total number of non-VLA elements.
3515  llvm::Value *numElements = getVLASize(vla).NumElts;
3516 
3517  // Effectively, the multiply by the VLA size is part of the GEP.
3518  // GEP indexes are signed, and scaling an index isn't permitted to
3519  // signed-overflow, so we use the same semantics for our explicit
3520  // multiply. We suppress this if overflow is not undefined behavior.
3521  if (getLangOpts().isSignedOverflowDefined()) {
3522  Idx = Builder.CreateMul(Idx, numElements);
3523  } else {
3524  Idx = Builder.CreateNSWMul(Idx, numElements);
3525  }
3526 
3527  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3529  SignedIndices, E->getExprLoc());
3530 
3531  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3532  // Indexing over an interface, as in "NSString *P; P[4];"
3533 
3534  // Emit the base pointer.
3535  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3536  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3537 
3538  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3539  llvm::Value *InterfaceSizeVal =
3540  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3541 
3542  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3543 
3544  // We don't necessarily build correct LLVM struct types for ObjC
3545  // interfaces, so we can't rely on GEP to do this scaling
3546  // correctly, so we need to cast to i8*. FIXME: is this actually
3547  // true? A lot of other things in the fragile ABI would break...
3548  llvm::Type *OrigBaseTy = Addr.getType();
3549  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3550 
3551  // Do the GEP.
3552  CharUnits EltAlign =
3553  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3554  llvm::Value *EltPtr =
3555  emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3556  SignedIndices, E->getExprLoc());
3557  Addr = Address(EltPtr, EltAlign);
3558 
3559  // Cast back.
3560  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3561  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3562  // If this is A[i] where A is an array, the frontend will have decayed the
3563  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3564  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3565  // "gep x, i" here. Emit one "gep A, 0, i".
3566  assert(Array->getType()->isArrayType() &&
3567  "Array to pointer decay must have array source type!");
3568  LValue ArrayLV;
3569  // For simple multidimensional array indexing, set the 'accessed' flag for
3570  // better bounds-checking of the base expression.
3571  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3572  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3573  else
3574  ArrayLV = EmitLValue(Array);
3575  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3576 
3577  // Propagate the alignment from the array itself to the result.
3578  QualType arrayType = Array->getType();
3579  Addr = emitArraySubscriptGEP(
3580  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3581  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3582  E->getExprLoc(), &arrayType);
3583  EltBaseInfo = ArrayLV.getBaseInfo();
3584  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3585  } else {
3586  // The base must be a pointer; emit it with an estimate of its alignment.
3587  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3588  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3589  QualType ptrType = E->getBase()->getType();
3590  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3592  SignedIndices, E->getExprLoc(), &ptrType);
3593  }
3594 
3595  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3596 
3597  if (getLangOpts().ObjC &&
3598  getLangOpts().getGC() != LangOptions::NonGC) {
3600  setObjCGCLValueClass(getContext(), E, LV);
3601  }
3602  return LV;
3603 }
3604 
3606  LValueBaseInfo &BaseInfo,
3607  TBAAAccessInfo &TBAAInfo,
3608  QualType BaseTy, QualType ElTy,
3609  bool IsLowerBound) {
3610  LValue BaseLVal;
3611  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3612  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3613  if (BaseTy->isArrayType()) {
3614  Address Addr = BaseLVal.getAddress();
3615  BaseInfo = BaseLVal.getBaseInfo();
3616 
3617  // If the array type was an incomplete type, we need to make sure
3618  // the decay ends up being the right type.
3619  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3620  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3621 
3622  // Note that VLA pointers are always decayed, so we don't need to do
3623  // anything here.
3624  if (!BaseTy->isVariableArrayType()) {
3625  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3626  "Expected pointer to array");
3627  Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3628  }
3629 
3630  return CGF.Builder.CreateElementBitCast(Addr,
3631  CGF.ConvertTypeForMem(ElTy));
3632  }
3633  LValueBaseInfo TypeBaseInfo;
3634  TBAAAccessInfo TypeTBAAInfo;
3635  CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3636  &TypeTBAAInfo);
3637  BaseInfo.mergeForCast(TypeBaseInfo);
3638  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3639  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3640  }
3641  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3642 }
3643 
3645  bool IsLowerBound) {
3647  QualType ResultExprTy;
3648  if (auto *AT = getContext().getAsArrayType(BaseTy))
3649  ResultExprTy = AT->getElementType();
3650  else
3651  ResultExprTy = BaseTy->getPointeeType();
3652  llvm::Value *Idx = nullptr;
3653  if (IsLowerBound || E->getColonLoc().isInvalid()) {
3654  // Requesting lower bound or upper bound, but without provided length and
3655  // without ':' symbol for the default length -> length = 1.
3656  // Idx = LowerBound ?: 0;
3657  if (auto *LowerBound = E->getLowerBound()) {
3658  Idx = Builder.CreateIntCast(
3659  EmitScalarExpr(LowerBound), IntPtrTy,
3660  LowerBound->getType()->hasSignedIntegerRepresentation());
3661  } else
3662  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3663  } else {
3664  // Try to emit length or lower bound as constant. If this is possible, 1
3665  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3666  // IR (LB + Len) - 1.
3667  auto &C = CGM.getContext();
3668  auto *Length = E->getLength();
3669  llvm::APSInt ConstLength;
3670  if (Length) {
3671  // Idx = LowerBound + Length - 1;
3672  if (Length->isIntegerConstantExpr(ConstLength, C)) {
3673  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3674  Length = nullptr;
3675  }
3676  auto *LowerBound = E->getLowerBound();
3677  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3678  if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3679  ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3680  LowerBound = nullptr;
3681  }
3682  if (!Length)
3683  --ConstLength;
3684  else if (!LowerBound)
3685  --ConstLowerBound;
3686 
3687  if (Length || LowerBound) {
3688  auto *LowerBoundVal =
3689  LowerBound
3690  ? Builder.CreateIntCast(
3691  EmitScalarExpr(LowerBound), IntPtrTy,
3692  LowerBound->getType()->hasSignedIntegerRepresentation())
3693  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3694  auto *LengthVal =
3695  Length
3696  ? Builder.CreateIntCast(
3697  EmitScalarExpr(Length), IntPtrTy,
3698  Length->getType()->hasSignedIntegerRepresentation())
3699  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3700  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3701  /*HasNUW=*/false,
3702  !getLangOpts().isSignedOverflowDefined());
3703  if (Length && LowerBound) {
3704  Idx = Builder.CreateSub(
3705  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3706  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3707  }
3708  } else
3709  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3710  } else {
3711  // Idx = ArraySize - 1;
3712  QualType ArrayTy = BaseTy->isPointerType()
3713  ? E->getBase()->IgnoreParenImpCasts()->getType()
3714  : BaseTy;
3715  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3716  Length = VAT->getSizeExpr();
3717  if (Length->isIntegerConstantExpr(ConstLength, C))
3718  Length = nullptr;
3719  } else {
3720  auto *CAT = C.getAsConstantArrayType(ArrayTy);
3721  ConstLength = CAT->getSize();
3722  }
3723  if (Length) {
3724  auto *LengthVal = Builder.CreateIntCast(
3725  EmitScalarExpr(Length), IntPtrTy,
3726  Length->getType()->hasSignedIntegerRepresentation());
3727  Idx = Builder.CreateSub(
3728  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3729  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3730  } else {
3731  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3732  --ConstLength;
3733  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3734  }
3735  }
3736  }
3737  assert(Idx);
3738 
3739  Address EltPtr = Address::invalid();
3740  LValueBaseInfo BaseInfo;
3741  TBAAAccessInfo TBAAInfo;
3742  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3743  // The base must be a pointer, which is not an aggregate. Emit
3744  // it. It needs to be emitted first in case it's what captures
3745  // the VLA bounds.
3746  Address Base =
3747  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3748  BaseTy, VLA->getElementType(), IsLowerBound);
3749  // The element count here is the total number of non-VLA elements.
3750  llvm::Value *NumElements = getVLASize(VLA).NumElts;
3751 
3752  // Effectively, the multiply by the VLA size is part of the GEP.
3753  // GEP indexes are signed, and scaling an index isn't permitted to
3754  // signed-overflow, so we use the same semantics for our explicit
3755  // multiply. We suppress this if overflow is not undefined behavior.
3756  if (getLangOpts().isSignedOverflowDefined())
3757  Idx = Builder.CreateMul(Idx, NumElements);
3758  else
3759  Idx = Builder.CreateNSWMul(Idx, NumElements);
3760  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3762  /*signedIndices=*/false, E->getExprLoc());
3763  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3764  // If this is A[i] where A is an array, the frontend will have decayed the
3765  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3766  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3767  // "gep x, i" here. Emit one "gep A, 0, i".
3768  assert(Array->getType()->isArrayType() &&
3769  "Array to pointer decay must have array source type!");
3770  LValue ArrayLV;
3771  // For simple multidimensional array indexing, set the 'accessed' flag for
3772  // better bounds-checking of the base expression.
3773  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3774  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3775  else
3776  ArrayLV = EmitLValue(Array);
3777 
3778  // Propagate the alignment from the array itself to the result.
3779  EltPtr = emitArraySubscriptGEP(
3780  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3781  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3782  /*signedIndices=*/false, E->getExprLoc());
3783  BaseInfo = ArrayLV.getBaseInfo();
3784  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3785  } else {
3786  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3787  TBAAInfo, BaseTy, ResultExprTy,
3788  IsLowerBound);
3789  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3790  !getLangOpts().isSignedOverflowDefined(),
3791  /*signedIndices=*/false, E->getExprLoc());
3792  }
3793 
3794  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3795 }
3796 
3799  // Emit the base vector as an l-value.
3800  LValue Base;
3801 
3802  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3803  if (E->isArrow()) {
3804  // If it is a pointer to a vector, emit the address and form an lvalue with
3805  // it.
3806  LValueBaseInfo BaseInfo;
3807  TBAAAccessInfo TBAAInfo;
3808  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3809  const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3810  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3811  Base.getQuals().removeObjCGCAttr();
3812  } else if (E->getBase()->isGLValue()) {
3813  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3814  // emit the base as an lvalue.
3815  assert(E->getBase()->getType()->isVectorType());
3816  Base = EmitLValue(E->getBase());
3817  } else {
3818  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3819  assert(E->getBase()->getType()->isVectorType() &&
3820  "Result must be a vector");
3821  llvm::Value *Vec = EmitScalarExpr(E->getBase());
3822 
3823  // Store the vector to memory (because LValue wants an address).
3824  Address VecMem = CreateMemTemp(E->getBase()->getType());
3825  Builder.CreateStore(Vec, VecMem);
3826  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3828  }
3829 
3830  QualType type =
3832 
3833  // Encode the element access list into a vector of unsigned indices.
3834  SmallVector<uint32_t, 4> Indices;
3835  E->getEncodedElementAccess(Indices);
3836 
3837  if (Base.isSimple()) {
3838  llvm::Constant *CV =
3839  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3840  return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3841  Base.getBaseInfo(), TBAAAccessInfo());
3842  }
3843  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3844 
3845  llvm::Constant *BaseElts = Base.getExtVectorElts();
3847 
3848  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3849  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3850  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3852  Base.getBaseInfo(), TBAAAccessInfo());
3853 }
3854 
3856  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3857  EmitIgnoredExpr(E->getBase());
3858  return EmitDeclRefLValue(DRE);
3859  }
3860 
3861  Expr *BaseExpr = E->getBase();
3862  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3863  LValue BaseLV;
3864  if (E->isArrow()) {
3865  LValueBaseInfo BaseInfo;
3866  TBAAAccessInfo TBAAInfo;
3867  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3868  QualType PtrTy = BaseExpr->getType()->getPointeeType();
3869  SanitizerSet SkippedChecks;
3870  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3871  if (IsBaseCXXThis)
3872  SkippedChecks.set(SanitizerKind::Alignment, true);
3873  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3874  SkippedChecks.set(SanitizerKind::Null, true);
3875  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3876  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3877  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3878  } else
3879  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3880 
3881  NamedDecl *ND = E->getMemberDecl();
3882  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3883  LValue LV = EmitLValueForField(BaseLV, Field);
3884  setObjCGCLValueClass(getContext(), E, LV);
3885  return LV;
3886  }
3887 
3888  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3889  return EmitFunctionDeclLValue(*this, E, FD);
3890 
3891  llvm_unreachable("Unhandled member declaration!");
3892 }
3893 
3894 /// Given that we are currently emitting a lambda, emit an l-value for
3895 /// one of its members.
3897  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3898  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3899  QualType LambdaTagType =
3900  getContext().getTagDeclType(Field->getParent());
3901  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3902  return EmitLValueForField(LambdaLV, Field);
3903 }
3904 
3905 /// Get the field index in the debug info. The debug info structure/union
3906 /// will ignore the unnamed bitfields.
3908  unsigned FieldIndex) {
3909  unsigned I = 0, Skipped = 0;
3910 
3911  for (auto F : Rec->getDefinition()->fields()) {
3912  if (I == FieldIndex)
3913  break;
3914  if (F->isUnnamedBitfield())
3915  Skipped++;
3916  I++;
3917  }
3918 
3919  return FieldIndex - Skipped;
3920 }
3921 
3922 /// Get the address of a zero-sized field within a record. The resulting
3923 /// address doesn't necessarily have the right type.
3925  const FieldDecl *Field) {
3927  CGF.getContext().getFieldOffset(Field));
3928  if (Offset.isZero())
3929  return Base;
3930  Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty);
3931  return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
3932 }
3933 
3934 /// Drill down to the storage of a field without walking into
3935 /// reference types.
3936 ///
3937 /// The resulting address doesn't necessarily have the right type.
3939  const FieldDecl *field) {
3940  if (field->isZeroSize(CGF.getContext()))
3941  return emitAddrOfZeroSizeField(CGF, base, field);
3942 
3943  const RecordDecl *rec = field->getParent();
3944 
3945  unsigned idx =
3946  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3947 
3948  return CGF.Builder.CreateStructGEP(base, idx, field->getName());
3949 }
3950 
3952  const FieldDecl *field) {
3953  const RecordDecl *rec = field->getParent();
3954  llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateRecordType(
3955  CGF.getContext().getRecordType(rec), rec->getLocation());
3956 
3957  unsigned idx =
3958  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3959 
3961  base, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
3962 }
3963 
3964 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3965  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3966  if (!RD)
3967  return false;
3968 
3969  if (RD->isDynamicClass())
3970  return true;
3971 
3972  for (const auto &Base : RD->bases())
3973  if (hasAnyVptr(Base.getType(), Context))
3974  return true;
3975 
3976  for (const FieldDecl *Field : RD->fields())
3977  if (hasAnyVptr(Field->getType(), Context))
3978  return true;
3979 
3980  return false;
3981 }
3982 
3984  const FieldDecl *field) {
3985  LValueBaseInfo BaseInfo = base.getBaseInfo();
3986 
3987  if (field->isBitField()) {
3988  const CGRecordLayout &RL =
3990  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3991  Address Addr = base.getAddress();
3992  unsigned Idx = RL.getLLVMFieldNo(field);
3993  if (Idx != 0)
3994  // For structs, we GEP to the field that the record layout suggests.
3995  Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
3996  // Get the access type.
3997  llvm::Type *FieldIntTy =
3998  llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3999  if (Addr.getElementType() != FieldIntTy)
4000  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
4001 
4002  QualType fieldType =
4003  field->getType().withCVRQualifiers(base.getVRQualifiers());
4004  // TODO: Support TBAA for bit fields.
4005  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4006  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4007  TBAAAccessInfo());
4008  }
4009 
4010  // Fields of may-alias structures are may-alias themselves.
4011  // FIXME: this should get propagated down through anonymous structs
4012  // and unions.
4013  QualType FieldType = field->getType();
4014  const RecordDecl *rec = field->getParent();
4015  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4016  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4017  TBAAAccessInfo FieldTBAAInfo;
4018  if (base.getTBAAInfo().isMayAlias() ||
4019  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4020  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4021  } else if (rec->isUnion()) {
4022  // TODO: Support TBAA for unions.
4023  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4024  } else {
4025  // If no base type been assigned for the base access, then try to generate
4026  // one for this base lvalue.
4027  FieldTBAAInfo = base.getTBAAInfo();
4028  if (!FieldTBAAInfo.BaseType) {
4029  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4030  assert(!FieldTBAAInfo.Offset &&
4031  "Nonzero offset for an access with no base type!");
4032  }
4033 
4034  // Adjust offset to be relative to the base type.
4035  const ASTRecordLayout &Layout =
4037  unsigned CharWidth = getContext().getCharWidth();
4038  if (FieldTBAAInfo.BaseType)
4039  FieldTBAAInfo.Offset +=
4040  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4041 
4042  // Update the final access type and size.
4043  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4044  FieldTBAAInfo.Size =
4045  getContext().getTypeSizeInChars(FieldType).getQuantity();
4046  }
4047 
4048  Address addr = base.getAddress();
4049  if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4050  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4051  ClassDef->isDynamicClass()) {
4052  // Getting to any field of dynamic object requires stripping dynamic
4053  // information provided by invariant.group. This is because accessing
4054  // fields may leak the real address of dynamic object, which could result
4055  // in miscompilation when leaked pointer would be compared.
4056  auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4057  addr = Address(stripped, addr.getAlignment());
4058  }
4059  }
4060 
4061  unsigned RecordCVR = base.getVRQualifiers();
4062  if (rec->isUnion()) {
4063  // For unions, there is no pointer adjustment.
4064  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4065  hasAnyVptr(FieldType, getContext()))
4066  // Because unions can easily skip invariant.barriers, we need to add
4067  // a barrier every time CXXRecord field with vptr is referenced.
4068  addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
4069  addr.getAlignment());
4070 
4071  if (IsInPreservedAIRegion) {
4072  // Remember the original union field index
4073  llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4074  getContext().getRecordType(rec), rec->getLocation());
4075  addr = Address(
4076  Builder.CreatePreserveUnionAccessIndex(
4077  addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4078  addr.getAlignment());
4079  }
4080 
4081  if (FieldType->isReferenceType())
4083  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4084  } else {
4085  if (!IsInPreservedAIRegion)
4086  // For structs, we GEP to the field that the record layout suggests.
4087  addr = emitAddrOfFieldStorage(*this, addr, field);
4088  else
4089  // Remember the original struct field index
4090  addr = emitPreserveStructAccess(*this, addr, field);
4091  }
4092 
4093  // If this is a reference field, load the reference right now.
4094  if (FieldType->isReferenceType()) {
4095  LValue RefLVal =
4096  MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4097  if (RecordCVR & Qualifiers::Volatile)
4098  RefLVal.getQuals().addVolatile();
4099  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4100 
4101  // Qualifiers on the struct don't apply to the referencee.
4102  RecordCVR = 0;
4103  FieldType = FieldType->getPointeeType();
4104  }
4105 
4106  // Make sure that the address is pointing to the right type. This is critical
4107  // for both unions and structs. A union needs a bitcast, a struct element
4108  // will need a bitcast if the LLVM type laid out doesn't match the desired
4109  // type.
4111  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4112 
4113  if (field->hasAttr<AnnotateAttr>())
4114  addr = EmitFieldAnnotations(field, addr);
4115 
4116  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4117  LV.getQuals().addCVRQualifiers(RecordCVR);
4118 
4119  // __weak attribute on a field is ignored.
4120  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4121  LV.getQuals().removeObjCGCAttr();
4122 
4123  return LV;
4124 }
4125 
4126 LValue
4128  const FieldDecl *Field) {
4129  QualType FieldType = Field->getType();
4130 
4131  if (!FieldType->isReferenceType())
4132  return EmitLValueForField(Base, Field);
4133 
4134  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
4135 
4136  // Make sure that the address is pointing to the right type.
4137  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4138  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4139 
4140  // TODO: Generate TBAA information that describes this access as a structure
4141  // member access and not just an access to an object of the field's type. This
4142  // should be similar to what we do in EmitLValueForField().
4143  LValueBaseInfo BaseInfo = Base.getBaseInfo();
4144  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4145  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4146  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4147  CGM.getTBAAInfoForSubobject(Base, FieldType));
4148 }
4149 
4151  if (E->isFileScope()) {
4153  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4154  }
4155  if (E->getType()->isVariablyModifiedType())
4156  // make sure to emit the VLA size.
4158 
4159  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4160  const Expr *InitExpr = E->getInitializer();
4161  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4162 
4163  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4164  /*Init*/ true);
4165 
4166  return Result;
4167 }
4168 
4170  if (!E->isGLValue())
4171  // Initializing an aggregate temporary in C++11: T{...}.
4172  return EmitAggExprToLValue(E);
4173 
4174  // An lvalue initializer list must be initializing a reference.
4175  assert(E->isTransparent() && "non-transparent glvalue init list");
4176  return EmitLValue(E->getInit(0));
4177 }
4178 
4179 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4180 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4181 /// LValue is returned and the current block has been terminated.
4183  const Expr *Operand) {
4184  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4185  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4186  return None;
4187  }
4188 
4189  return CGF.EmitLValue(Operand);
4190 }
4191 
4194  if (!expr->isGLValue()) {
4195  // ?: here should be an aggregate.
4196  assert(hasAggregateEvaluationKind(expr->getType()) &&
4197  "Unexpected conditional operator!");
4198  return EmitAggExprToLValue(expr);
4199  }
4200 
4201  OpaqueValueMapping binding(*this, expr);
4202 
4203  const Expr *condExpr = expr->getCond();
4204  bool CondExprBool;
4205  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4206  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4207  if (!CondExprBool) std::swap(live, dead);
4208 
4209  if (!ContainsLabel(dead)) {
4210  // If the true case is live, we need to track its region.
4211  if (CondExprBool)
4213  return EmitLValue(live);
4214  }
4215  }
4216 
4217  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4218  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4219  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4220 
4221  ConditionalEvaluation eval(*this);
4222  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4223 
4224  // Any temporaries created here are conditional.
4225  EmitBlock(lhsBlock);
4227  eval.begin(*this);
4228  Optional<LValue> lhs =
4229  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4230  eval.end(*this);
4231 
4232  if (lhs && !lhs->isSimple())
4233  return EmitUnsupportedLValue(expr, "conditional operator");
4234 
4235  lhsBlock = Builder.GetInsertBlock();
4236  if (lhs)
4237  Builder.CreateBr(contBlock);
4238 
4239  // Any temporaries created here are conditional.
4240  EmitBlock(rhsBlock);
4241  eval.begin(*this);
4242  Optional<LValue> rhs =
4243  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4244  eval.end(*this);
4245  if (rhs && !rhs->isSimple())
4246  return EmitUnsupportedLValue(expr, "conditional operator");
4247  rhsBlock = Builder.GetInsertBlock();
4248 
4249  EmitBlock(contBlock);
4250 
4251  if (lhs && rhs) {
4252  llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4253  2, "cond-lvalue");
4254  phi->addIncoming(lhs->getPointer(), lhsBlock);
4255  phi->addIncoming(rhs->getPointer(), rhsBlock);
4256  Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4257  AlignmentSource alignSource =
4258  std::max(lhs->getBaseInfo().getAlignmentSource(),
4259  rhs->getBaseInfo().getAlignmentSource());
4261  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4262  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4263  TBAAInfo);
4264  } else {
4265  assert((lhs || rhs) &&
4266  "both operands of glvalue conditional are throw-expressions?");
4267  return lhs ? *lhs : *rhs;
4268  }
4269 }
4270 
4271 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4272 /// type. If the cast is to a reference, we can have the usual lvalue result,
4273 /// otherwise if a cast is needed by the code generator in an lvalue context,
4274 /// then it must mean that we need the address of an aggregate in order to
4275 /// access one of its members. This can happen for all the reasons that casts
4276 /// are permitted with aggregate result, including noop aggregate casts, and
4277 /// cast from scalar to union.
4279  switch (E->getCastKind()) {
4280  case CK_ToVoid:
4281  case CK_BitCast:
4282  case CK_LValueToRValueBitCast:
4283  case CK_ArrayToPointerDecay:
4284  case CK_FunctionToPointerDecay:
4285  case CK_NullToMemberPointer:
4286  case CK_NullToPointer:
4287  case CK_IntegralToPointer:
4288  case CK_PointerToIntegral:
4289  case CK_PointerToBoolean:
4290  case CK_VectorSplat:
4291  case CK_IntegralCast:
4292  case CK_BooleanToSignedIntegral:
4293  case CK_IntegralToBoolean:
4294  case CK_IntegralToFloating:
4295  case CK_FloatingToIntegral:
4296  case CK_FloatingToBoolean:
4297  case CK_FloatingCast:
4298  case CK_FloatingRealToComplex:
4299  case CK_FloatingComplexToReal:
4300  case CK_FloatingComplexToBoolean:
4301  case CK_FloatingComplexCast:
4302  case CK_FloatingComplexToIntegralComplex:
4303  case CK_IntegralRealToComplex:
4304  case CK_IntegralComplexToReal:
4305  case CK_IntegralComplexToBoolean:
4306  case CK_IntegralComplexCast:
4307  case CK_IntegralComplexToFloatingComplex:
4308  case CK_DerivedToBaseMemberPointer:
4309  case CK_BaseToDerivedMemberPointer:
4310  case CK_MemberPointerToBoolean:
4311  case CK_ReinterpretMemberPointer:
4312  case CK_AnyPointerToBlockPointerCast:
4313  case CK_ARCProduceObject:
4314  case CK_ARCConsumeObject:
4315  case CK_ARCReclaimReturnedObject:
4316  case CK_ARCExtendBlockObject:
4317  case CK_CopyAndAutoreleaseBlockObject:
4318  case CK_IntToOCLSampler:
4319  case CK_FixedPointCast:
4320  case CK_FixedPointToBoolean:
4321  case CK_FixedPointToIntegral:
4322  case CK_IntegralToFixedPoint:
4323  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4324 
4325  case CK_Dependent:
4326  llvm_unreachable("dependent cast kind in IR gen!");
4327 
4328  case CK_BuiltinFnToFnPtr:
4329  llvm_unreachable("builtin functions are handled elsewhere");
4330 
4331  // These are never l-values; just use the aggregate emission code.
4332  case CK_NonAtomicToAtomic:
4333  case CK_AtomicToNonAtomic:
4334  return EmitAggExprToLValue(E);
4335 
4336  case CK_Dynamic: {
4337  LValue LV = EmitLValue(E->getSubExpr());
4338  Address V = LV.getAddress();
4339  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4340  return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4341  }
4342 
4343  case CK_ConstructorConversion:
4344  case CK_UserDefinedConversion:
4345  case CK_CPointerToObjCPointerCast:
4346  case CK_BlockPointerToObjCPointerCast:
4347  case CK_NoOp:
4348  case CK_LValueToRValue:
4349  return EmitLValue(E->getSubExpr());
4350 
4351  case CK_UncheckedDerivedToBase:
4352  case CK_DerivedToBase: {
4353  const RecordType *DerivedClassTy =
4354  E->getSubExpr()->getType()->getAs<RecordType>();
4355  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4356 
4357  LValue LV = EmitLValue(E->getSubExpr());
4358  Address This = LV.getAddress();
4359 
4360  // Perform the derived-to-base conversion
4362  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4363  /*NullCheckValue=*/false, E->getExprLoc());
4364 
4365  // TODO: Support accesses to members of base classes in TBAA. For now, we
4366  // conservatively pretend that the complete object is of the base class
4367  // type.
4368  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4369  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4370  }
4371  case CK_ToUnion:
4372  return EmitAggExprToLValue(E);
4373  case CK_BaseToDerived: {
4374  const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4375  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4376 
4377  LValue LV = EmitLValue(E->getSubExpr());
4378 
4379  // Perform the base-to-derived conversion
4380  Address Derived =
4381  GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4382  E->path_begin(), E->path_end(),
4383  /*NullCheckValue=*/false);
4384 
4385  // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4386  // performed and the object is not of the derived type.
4389  Derived.getPointer(), E->getType());
4390 
4391  if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4392  EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4393  /*MayBeNull=*/false, CFITCK_DerivedCast,
4394  E->getBeginLoc());
4395 
4396  return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4397  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4398  }
4399  case CK_LValueBitCast: {
4400  // This must be a reinterpret_cast (or c-style equivalent).
4401  const auto *CE = cast<ExplicitCastExpr>(E);
4402 
4403  CGM.EmitExplicitCastExprType(CE, this);
4404  LValue LV = EmitLValue(E->getSubExpr());
4406  ConvertType(CE->getTypeAsWritten()));
4407 
4408  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4409  EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4410  /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4411  E->getBeginLoc());
4412 
4413  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4414  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4415  }
4416  case CK_AddressSpaceConversion: {
4417  LValue LV = EmitLValue(E->getSubExpr());
4418  QualType DestTy = getContext().getPointerType(E->getType());
4420  *this, LV.getPointer(), E->getSubExpr()->getType().getAddressSpace(),
4421  E->getType().getAddressSpace(), ConvertType(DestTy));
4422  return MakeAddrLValue(Address(V, LV.getAddress().getAlignment()),
4423  E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4424  }
4425  case CK_ObjCObjectLValueCast: {
4426  LValue LV = EmitLValue(E->getSubExpr());
4428  ConvertType(E->getType()));
4429  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4430  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4431  }
4432  case CK_ZeroToOCLOpaqueType:
4433  llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4434  }
4435 
4436  llvm_unreachable("Unhandled lvalue cast kind?");
4437 }
4438 
4442 }
4443 
4444 LValue
4447 
4448  llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4449  it = OpaqueLValues.find(e);
4450 
4451  if (it != OpaqueLValues.end())
4452  return it->second;
4453 
4454  assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4455  return EmitLValue(e->getSourceExpr());
4456 }
4457 
4458 RValue
4461 
4462  llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4463  it = OpaqueRValues.find(e);
4464 
4465  if (it != OpaqueRValues.end())
4466  return it->second;
4467 
4468  assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4469  return EmitAnyExpr(e->getSourceExpr());
4470 }
4471 
4473  const FieldDecl *FD,
4474  SourceLocation Loc) {
4475  QualType FT = FD->getType();
4476  LValue FieldLV = EmitLValueForField(LV, FD);
4477  switch (getEvaluationKind(FT)) {
4478  case TEK_Complex:
4479  return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4480  case TEK_Aggregate:
4481  return FieldLV.asAggregateRValue();
4482  case TEK_Scalar:
4483  // This routine is used to load fields one-by-one to perform a copy, so
4484  // don't load reference fields.
4485  if (FD->getType()->isReferenceType())
4486  return RValue::get(FieldLV.getPointer());
4487  return EmitLoadOfLValue(FieldLV, Loc);
4488  }
4489  llvm_unreachable("bad evaluation kind");
4490 }
4491 
4492 //===--------------------------------------------------------------------===//
4493 // Expression Emission
4494 //===--------------------------------------------------------------------===//
4495 
4498  // Builtins never have block type.
4499  if (E->getCallee()->getType()->isBlockPointerType())
4500  return EmitBlockCallExpr(E, ReturnValue);
4501 
4502  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4503  return EmitCXXMemberCallExpr(CE, ReturnValue);
4504 
4505  if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4506  return EmitCUDAKernelCallExpr(CE, ReturnValue);
4507 
4508  if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4509  if (const CXXMethodDecl *MD =
4510  dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4511  return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4512 
4513  CGCallee callee = EmitCallee(E->getCallee());
4514 
4515  if (callee.isBuiltin()) {
4516  return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4517  E, ReturnValue);
4518  }
4519 
4520  if (callee.isPseudoDestructor()) {
4522  }
4523 
4524  return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4525 }
4526 
4527 /// Emit a CallExpr without considering whether it might be a subclass.
4530  CGCallee Callee = EmitCallee(E->getCallee());
4531  return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4532 }
4533 
4535  if (auto builtinID = FD->getBuiltinID()) {
4536  return CGCallee::forBuiltin(builtinID, FD);
4537  }
4538 
4539  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4540  return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
4541 }
4542 
4544  E = E->IgnoreParens();
4545 
4546  // Look through function-to-pointer decay.
4547  if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4548  if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4549  ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4550  return EmitCallee(ICE->getSubExpr());
4551  }
4552 
4553  // Resolve direct calls.
4554  } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4555  if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4556  return EmitDirectCallee(*this, FD);
4557  }
4558  } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4559  if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4560  EmitIgnoredExpr(ME->getBase());
4561  return EmitDirectCallee(*this, FD);
4562  }
4563 
4564  // Look through template substitutions.
4565  } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4566  return EmitCallee(NTTP->getReplacement());
4567 
4568  // Treat pseudo-destructor calls differently.
4569  } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4570  return CGCallee::forPseudoDestructor(PDE);
4571  }
4572 
4573  // Otherwise, we have an indirect reference.
4574  llvm::Value *calleePtr;
4576  if (auto ptrType = E->getType()->getAs<PointerType>()) {
4577  calleePtr = EmitScalarExpr(E);
4578  functionType = ptrType->getPointeeType();
4579  } else {
4580  functionType = E->getType();
4581  calleePtr = EmitLValue(E).getPointer();
4582  }
4583  assert(functionType->isFunctionType());
4584 
4585  GlobalDecl GD;
4586  if (const auto *VD =
4587  dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4588  GD = GlobalDecl(VD);
4589 
4590  CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4591  CGCallee callee(calleeInfo, calleePtr);
4592  return callee;
4593 }
4594 
4596  // Comma expressions just emit their LHS then their RHS as an l-value.
4597  if (E->getOpcode() == BO_Comma) {
4598  EmitIgnoredExpr(E->getLHS());
4600  return EmitLValue(E->getRHS());
4601  }
4602 
4603  if (E->getOpcode() == BO_PtrMemD ||
4604  E->getOpcode() == BO_PtrMemI)
4606 
4607  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4608 
4609  // Note that in all of these cases, __block variables need the RHS
4610  // evaluated first just in case the variable gets moved by the RHS.
4611 
4612  switch (getEvaluationKind(E->getType())) {
4613  case TEK_Scalar: {
4614  switch (E->getLHS()->getType().getObjCLifetime()) {
4616  return EmitARCStoreStrong(E, /*ignored*/ false).first;
4617 
4619  return EmitARCStoreAutoreleasing(E).first;
4620 
4621  // No reason to do any of these differently.
4622  case Qualifiers::OCL_None:
4624  case Qualifiers::OCL_Weak:
4625  break;
4626  }
4627 
4628  RValue RV = EmitAnyExpr(E->getRHS());
4630  if (RV.isScalar())
4632  EmitStoreThroughLValue(RV, LV);
4633  return LV;
4634  }
4635 
4636  case TEK_Complex:
4637  return EmitComplexAssignmentLValue(E);
4638 
4639  case TEK_Aggregate:
4640  return EmitAggExprToLValue(E);
4641  }
4642  llvm_unreachable("bad evaluation kind");
4643 }
4644 
4646  RValue RV = EmitCallExpr(E);
4647 
4648  if (!RV.isScalar())
4649  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4651 
4652  assert(E->getCallReturnType(getContext())->isReferenceType() &&
4653  "Can't have a scalar return unless the return type is a "
4654  "reference type!");
4655 
4657 }
4658 
4660  // FIXME: This shouldn't require another copy.
4661  return EmitAggExprToLValue(E);
4662 }
4663 
4666  && "binding l-value to type which needs a temporary");
4667  AggValueSlot Slot = CreateAggTemp(E->getType());
4668  EmitCXXConstructExpr(E, Slot);
4669  return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4670 }
4671 
4672 LValue
4675 }
4676 
4679  ConvertType(E->getType()));
4680 }
4681 
4683  return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4685 }
4686 
4687 LValue
4689  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4690  Slot.setExternallyDestructed();
4691  EmitAggExpr(E->getSubExpr(), Slot);
4692  EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4694 }
4695 
4697  RValue RV = EmitObjCMessageExpr(E);
4698 
4699  if (!RV.isScalar())
4700  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4702 
4703  assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4704  "Can't have a scalar return unless the return type is a "
4705  "reference type!");
4706 
4708 }
4709 
4711  Address V =
4713  return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4714 }
4715 
4717  const ObjCIvarDecl *Ivar) {
4718  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4719 }
4720 
4722  llvm::Value *BaseValue,
4723  const ObjCIvarDecl *Ivar,
4724  unsigned CVRQualifiers) {
4725  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4726  Ivar, CVRQualifiers);
4727 }
4728 
4730  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4731  llvm::Value *BaseValue = nullptr;
4732  const Expr *BaseExpr = E->getBase();
4733  Qualifiers BaseQuals;
4734  QualType ObjectTy;
4735  if (E->isArrow()) {
4736  BaseValue = EmitScalarExpr(BaseExpr);
4737  ObjectTy = BaseExpr->getType()->getPointeeType();
4738  BaseQuals = ObjectTy.getQualifiers();
4739  } else {
4740  LValue BaseLV = EmitLValue(BaseExpr);
4741  BaseValue = BaseLV.getPointer();
4742  ObjectTy = BaseExpr->getType();
4743  BaseQuals = ObjectTy.getQualifiers();
4744  }
4745 
4746  LValue LV =
4747  EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4748  BaseQuals.getCVRQualifiers());
4749  setObjCGCLValueClass(getContext(), E, LV);
4750  return LV;
4751 }
4752 
4754  // Can only get l-value for message expression returning aggregate type
4755  RValue RV = EmitAnyExprToTemp(E);
4756  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4758 }
4759 
4760 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4762  llvm::Value *Chain) {
4763  // Get the actual function type. The callee type will always be a pointer to
4764  // function type or a block pointer type.
4765  assert(CalleeType->isFunctionPointerType() &&
4766  "Call must have function pointer type!");
4767 
4768  const Decl *TargetDecl =
4769  OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
4770 
4771  CalleeType = getContext().getCanonicalType(CalleeType);
4772 
4773  auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4774 
4775  CGCallee Callee = OrigCallee;
4776