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.getAsAlign());
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().getAsAlign());
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.getAsAlign());
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()->castAs<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::CXXRewrittenBinaryOperatorClass:
1271  return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm());
1272  case Expr::VAArgExprClass:
1273  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1274  case Expr::DeclRefExprClass:
1275  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1276  case Expr::ConstantExprClass:
1277  return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1278  case Expr::ParenExprClass:
1279  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1280  case Expr::GenericSelectionExprClass:
1281  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1282  case Expr::PredefinedExprClass:
1283  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1284  case Expr::StringLiteralClass:
1285  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1286  case Expr::ObjCEncodeExprClass:
1287  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1288  case Expr::PseudoObjectExprClass:
1289  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1290  case Expr::InitListExprClass:
1291  return EmitInitListLValue(cast<InitListExpr>(E));
1292  case Expr::CXXTemporaryObjectExprClass:
1293  case Expr::CXXConstructExprClass:
1294  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1295  case Expr::CXXBindTemporaryExprClass:
1296  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1297  case Expr::CXXUuidofExprClass:
1298  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1299  case Expr::LambdaExprClass:
1300  return EmitAggExprToLValue(E);
1301 
1302  case Expr::ExprWithCleanupsClass: {
1303  const auto *cleanups = cast<ExprWithCleanups>(E);
1304  enterFullExpression(cleanups);
1305  RunCleanupsScope Scope(*this);
1306  LValue LV = EmitLValue(cleanups->getSubExpr());
1307  if (LV.isSimple()) {
1308  // Defend against branches out of gnu statement expressions surrounded by
1309  // cleanups.
1310  llvm::Value *V = LV.getPointer();
1311  Scope.ForceCleanup({&V});
1312  return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1313  getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1314  }
1315  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1316  // bitfield lvalue or some other non-simple lvalue?
1317  return LV;
1318  }
1319 
1320  case Expr::CXXDefaultArgExprClass: {
1321  auto *DAE = cast<CXXDefaultArgExpr>(E);
1322  CXXDefaultArgExprScope Scope(*this, DAE);
1323  return EmitLValue(DAE->getExpr());
1324  }
1325  case Expr::CXXDefaultInitExprClass: {
1326  auto *DIE = cast<CXXDefaultInitExpr>(E);
1327  CXXDefaultInitExprScope Scope(*this, DIE);
1328  return EmitLValue(DIE->getExpr());
1329  }
1330  case Expr::CXXTypeidExprClass:
1331  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1332 
1333  case Expr::ObjCMessageExprClass:
1334  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1335  case Expr::ObjCIvarRefExprClass:
1336  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1337  case Expr::StmtExprClass:
1338  return EmitStmtExprLValue(cast<StmtExpr>(E));
1339  case Expr::UnaryOperatorClass:
1340  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1341  case Expr::ArraySubscriptExprClass:
1342  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1343  case Expr::OMPArraySectionExprClass:
1344  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1345  case Expr::ExtVectorElementExprClass:
1346  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1347  case Expr::MemberExprClass:
1348  return EmitMemberExpr(cast<MemberExpr>(E));
1349  case Expr::CompoundLiteralExprClass:
1350  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1351  case Expr::ConditionalOperatorClass:
1352  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1353  case Expr::BinaryConditionalOperatorClass:
1354  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1355  case Expr::ChooseExprClass:
1356  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1357  case Expr::OpaqueValueExprClass:
1358  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1359  case Expr::SubstNonTypeTemplateParmExprClass:
1360  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1361  case Expr::ImplicitCastExprClass:
1362  case Expr::CStyleCastExprClass:
1363  case Expr::CXXFunctionalCastExprClass:
1364  case Expr::CXXStaticCastExprClass:
1365  case Expr::CXXDynamicCastExprClass:
1366  case Expr::CXXReinterpretCastExprClass:
1367  case Expr::CXXConstCastExprClass:
1368  case Expr::ObjCBridgedCastExprClass:
1369  return EmitCastLValue(cast<CastExpr>(E));
1370 
1371  case Expr::MaterializeTemporaryExprClass:
1372  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1373 
1374  case Expr::CoawaitExprClass:
1375  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1376  case Expr::CoyieldExprClass:
1377  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1378  }
1379 }
1380 
1381 /// Given an object of the given canonical type, can we safely copy a
1382 /// value out of it based on its initializer?
1384  assert(type.isCanonical());
1385  assert(!type->isReferenceType());
1386 
1387  // Must be const-qualified but non-volatile.
1388  Qualifiers qs = type.getLocalQualifiers();
1389  if (!qs.hasConst() || qs.hasVolatile()) return false;
1390 
1391  // Otherwise, all object types satisfy this except C++ classes with
1392  // mutable subobjects or non-trivial copy/destroy behavior.
1393  if (const auto *RT = dyn_cast<RecordType>(type))
1394  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1395  if (RD->hasMutableFields() || !RD->isTrivial())
1396  return false;
1397 
1398  return true;
1399 }
1400 
1401 /// Can we constant-emit a load of a reference to a variable of the
1402 /// given type? This is different from predicates like
1403 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1404 /// in situations that don't necessarily satisfy the language's rules
1405 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1406 /// to do this with const float variables even if those variables
1407 /// aren't marked 'constexpr'.
1413 };
1415  type = type.getCanonicalType();
1416  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1417  if (isConstantEmittableObjectType(ref->getPointeeType()))
1418  return CEK_AsValueOrReference;
1419  return CEK_AsReferenceOnly;
1420  }
1422  return CEK_AsValueOnly;
1423  return CEK_None;
1424 }
1425 
1426 /// Try to emit a reference to the given value without producing it as
1427 /// an l-value. This is just an optimization, but it avoids us needing
1428 /// to emit global copies of variables if they're named without triggering
1429 /// a formal use in a context where we can't emit a direct reference to them,
1430 /// for instance if a block or lambda or a member of a local class uses a
1431 /// const int variable or constexpr variable from an enclosing function.
1434  ValueDecl *value = refExpr->getDecl();
1435 
1436  // The value needs to be an enum constant or a constant variable.
1438  if (isa<ParmVarDecl>(value)) {
1439  CEK = CEK_None;
1440  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1441  CEK = checkVarTypeForConstantEmission(var->getType());
1442  } else if (isa<EnumConstantDecl>(value)) {
1443  CEK = CEK_AsValueOnly;
1444  } else {
1445  CEK = CEK_None;
1446  }
1447  if (CEK == CEK_None) return ConstantEmission();
1448 
1449  Expr::EvalResult result;
1450  bool resultIsReference;
1451  QualType resultType;
1452 
1453  // It's best to evaluate all the way as an r-value if that's permitted.
1454  if (CEK != CEK_AsReferenceOnly &&
1455  refExpr->EvaluateAsRValue(result, getContext())) {
1456  resultIsReference = false;
1457  resultType = refExpr->getType();
1458 
1459  // Otherwise, try to evaluate as an l-value.
1460  } else if (CEK != CEK_AsValueOnly &&
1461  refExpr->EvaluateAsLValue(result, getContext())) {
1462  resultIsReference = true;
1463  resultType = value->getType();
1464 
1465  // Failure.
1466  } else {
1467  return ConstantEmission();
1468  }
1469 
1470  // In any case, if the initializer has side-effects, abandon ship.
1471  if (result.HasSideEffects)
1472  return ConstantEmission();
1473 
1474  // Emit as a constant.
1475  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1476  result.Val, resultType);
1477 
1478  // Make sure we emit a debug reference to the global variable.
1479  // This should probably fire even for
1480  if (isa<VarDecl>(value)) {
1481  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1482  EmitDeclRefExprDbgValue(refExpr, result.Val);
1483  } else {
1484  assert(isa<EnumConstantDecl>(value));
1485  EmitDeclRefExprDbgValue(refExpr, result.Val);
1486  }
1487 
1488  // If we emitted a reference constant, we need to dereference that.
1489  if (resultIsReference)
1491 
1492  return ConstantEmission::forValue(C);
1493 }
1494 
1496  const MemberExpr *ME) {
1497  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1498  // Try to emit static variable member expressions as DREs.
1499  return DeclRefExpr::Create(
1501  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1502  ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1503  }
1504  return nullptr;
1505 }
1506 
1509  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1510  return tryEmitAsConstant(DRE);
1511  return ConstantEmission();
1512 }
1513 
1515  const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1516  assert(Constant && "not a constant");
1517  if (Constant.isReference())
1518  return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1519  E->getExprLoc())
1520  .getScalarVal();
1521  return Constant.getValue();
1522 }
1523 
1525  SourceLocation Loc) {
1526  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1527  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1528  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1529 }
1530 
1532  if (Ty->isBooleanType())
1533  return true;
1534 
1535  if (const EnumType *ET = Ty->getAs<EnumType>())
1536  return ET->getDecl()->getIntegerType()->isBooleanType();
1537 
1538  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1539  return hasBooleanRepresentation(AT->getValueType());
1540 
1541  return false;
1542 }
1543 
1545  llvm::APInt &Min, llvm::APInt &End,
1546  bool StrictEnums, bool IsBool) {
1547  const EnumType *ET = Ty->getAs<EnumType>();
1548  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1549  ET && !ET->getDecl()->isFixed();
1550  if (!IsBool && !IsRegularCPlusPlusEnum)
1551  return false;
1552 
1553  if (IsBool) {
1554  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1555  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1556  } else {
1557  const EnumDecl *ED = ET->getDecl();
1558  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1559  unsigned Bitwidth = LTy->getScalarSizeInBits();
1560  unsigned NumNegativeBits = ED->getNumNegativeBits();
1561  unsigned NumPositiveBits = ED->getNumPositiveBits();
1562 
1563  if (NumNegativeBits) {
1564  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1565  assert(NumBits <= Bitwidth);
1566  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1567  Min = -End;
1568  } else {
1569  assert(NumPositiveBits <= Bitwidth);
1570  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1571  Min = llvm::APInt(Bitwidth, 0);
1572  }
1573  }
1574  return true;
1575 }
1576 
1577 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1578  llvm::APInt Min, End;
1579  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1581  return nullptr;
1582 
1583  llvm::MDBuilder MDHelper(getLLVMContext());
1584  return MDHelper.createRange(Min, End);
1585 }
1586 
1588  SourceLocation Loc) {
1589  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1590  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1591  if (!HasBoolCheck && !HasEnumCheck)
1592  return false;
1593 
1594  bool IsBool = hasBooleanRepresentation(Ty) ||
1595  NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1596  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1597  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1598  if (!NeedsBoolCheck && !NeedsEnumCheck)
1599  return false;
1600 
1601  // Single-bit booleans don't need to be checked. Special-case this to avoid
1602  // a bit width mismatch when handling bitfield values. This is handled by
1603  // EmitFromMemory for the non-bitfield case.
1604  if (IsBool &&
1605  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1606  return false;
1607 
1608  llvm::APInt Min, End;
1609  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1610  return true;
1611 
1612  auto &Ctx = getLLVMContext();
1613  SanitizerScope SanScope(this);
1614  llvm::Value *Check;
1615  --End;
1616  if (!Min) {
1617  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1618  } else {
1619  llvm::Value *Upper =
1620  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1621  llvm::Value *Lower =
1622  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1623  Check = Builder.CreateAnd(Upper, Lower);
1624  }
1625  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1628  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1629  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1630  StaticArgs, EmitCheckValue(Value));
1631  return true;
1632 }
1633 
1635  QualType Ty,
1636  SourceLocation Loc,
1637  LValueBaseInfo BaseInfo,
1638  TBAAAccessInfo TBAAInfo,
1639  bool isNontemporal) {
1640  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1641  // For better performance, handle vector loads differently.
1642  if (Ty->isVectorType()) {
1643  const llvm::Type *EltTy = Addr.getElementType();
1644 
1645  const auto *VTy = cast<llvm::VectorType>(EltTy);
1646 
1647  // Handle vectors of size 3 like size 4 for better performance.
1648  if (VTy->getNumElements() == 3) {
1649 
1650  // Bitcast to vec4 type.
1651  llvm::VectorType *vec4Ty =
1652  llvm::VectorType::get(VTy->getElementType(), 4);
1653  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1654  // Now load value.
1655  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1656 
1657  // Shuffle vector to get vec3.
1658  V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1659  {0, 1, 2}, "extractVec");
1660  return EmitFromMemory(V, Ty);
1661  }
1662  }
1663  }
1664 
1665  // Atomic operations have to be done on integral types.
1666  LValue AtomicLValue =
1667  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1668  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1669  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1670  }
1671 
1672  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1673  if (isNontemporal) {
1674  llvm::MDNode *Node = llvm::MDNode::get(
1675  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1676  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1677  }
1678 
1679  CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1680 
1681  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1682  // In order to prevent the optimizer from throwing away the check, don't
1683  // attach range metadata to the load.
1684  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1685  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1686  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1687 
1688  return EmitFromMemory(Load, Ty);
1689 }
1690 
1692  // Bool has a different representation in memory than in registers.
1693  if (hasBooleanRepresentation(Ty)) {
1694  // This should really always be an i1, but sometimes it's already
1695  // an i8, and it's awkward to track those cases down.
1696  if (Value->getType()->isIntegerTy(1))
1697  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1698  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1699  "wrong value rep of bool");
1700  }
1701 
1702  return Value;
1703 }
1704 
1706  // Bool has a different representation in memory than in registers.
1707  if (hasBooleanRepresentation(Ty)) {
1708  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1709  "wrong value rep of bool");
1710  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1711  }
1712 
1713  return Value;
1714 }
1715 
1717  bool Volatile, QualType Ty,
1718  LValueBaseInfo BaseInfo,
1719  TBAAAccessInfo TBAAInfo,
1720  bool isInit, bool isNontemporal) {
1721  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1722  // Handle vectors differently to get better performance.
1723  if (Ty->isVectorType()) {
1724  llvm::Type *SrcTy = Value->getType();
1725  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1726  // Handle vec3 special.
1727  if (VecTy && VecTy->getNumElements() == 3) {
1728  // Our source is a vec3, do a shuffle vector to make it a vec4.
1729  llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1730  Builder.getInt32(2),
1731  llvm::UndefValue::get(Builder.getInt32Ty())};
1732  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1733  Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1734  MaskV, "extractVec");
1735  SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1736  }
1737  if (Addr.getElementType() != SrcTy) {
1738  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1739  }
1740  }
1741  }
1742 
1743  Value = EmitToMemory(Value, Ty);
1744 
1745  LValue AtomicLValue =
1746  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1747  if (Ty->isAtomicType() ||
1748  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1749  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1750  return;
1751  }
1752 
1753  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1754  if (isNontemporal) {
1755  llvm::MDNode *Node =
1756  llvm::MDNode::get(Store->getContext(),
1757  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1758  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1759  }
1760 
1761  CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1762 }
1763 
1765  bool isInit) {
1766  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1767  lvalue.getType(), lvalue.getBaseInfo(),
1768  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1769 }
1770 
1771 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1772 /// method emits the address of the lvalue, then loads the result as an rvalue,
1773 /// returning the rvalue.
1775  if (LV.isObjCWeak()) {
1776  // load of a __weak object.
1777  Address AddrWeakObj = LV.getAddress();
1779  AddrWeakObj));
1780  }
1782  // In MRC mode, we do a load+autorelease.
1783  if (!getLangOpts().ObjCAutoRefCount) {
1784  return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1785  }
1786 
1787  // In ARC mode, we load retained and then consume the value.
1789  Object = EmitObjCConsumeObject(LV.getType(), Object);
1790  return RValue::get(Object);
1791  }
1792 
1793  if (LV.isSimple()) {
1794  assert(!LV.getType()->isFunctionType());
1795 
1796  // Everything needs a load.
1797  return RValue::get(EmitLoadOfScalar(LV, Loc));
1798  }
1799 
1800  if (LV.isVectorElt()) {
1801  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1802  LV.isVolatileQualified());
1803  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1804  "vecext"));
1805  }
1806 
1807  // If this is a reference to a subset of the elements of a vector, either
1808  // shuffle the input or extract/insert them as appropriate.
1809  if (LV.isExtVectorElt())
1811 
1812  // Global Register variables always invoke intrinsics
1813  if (LV.isGlobalReg())
1814  return EmitLoadOfGlobalRegLValue(LV);
1815 
1816  assert(LV.isBitField() && "Unknown LValue type!");
1817  return EmitLoadOfBitfieldLValue(LV, Loc);
1818 }
1819 
1821  SourceLocation Loc) {
1822  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1823 
1824  // Get the output type.
1825  llvm::Type *ResLTy = ConvertType(LV.getType());
1826 
1827  Address Ptr = LV.getBitFieldAddress();
1828  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1829 
1830  if (Info.IsSigned) {
1831  assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1832  unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1833  if (HighBits)
1834  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1835  if (Info.Offset + HighBits)
1836  Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1837  } else {
1838  if (Info.Offset)
1839  Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1840  if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1841  Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1842  Info.Size),
1843  "bf.clear");
1844  }
1845  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1846  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1847  return RValue::get(Val);
1848 }
1849 
1850 // If this is a reference to a subset of the elements of a vector, create an
1851 // appropriate shufflevector.
1854  LV.isVolatileQualified());
1855 
1856  const llvm::Constant *Elts = LV.getExtVectorElts();
1857 
1858  // If the result of the expression is a non-vector type, we must be extracting
1859  // a single element. Just codegen as an extractelement.
1860  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1861  if (!ExprVT) {
1862  unsigned InIdx = getAccessedFieldNo(0, Elts);
1863  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1864  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1865  }
1866 
1867  // Always use shuffle vector to try to retain the original program structure
1868  unsigned NumResultElts = ExprVT->getNumElements();
1869 
1871  for (unsigned i = 0; i != NumResultElts; ++i)
1872  Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1873 
1874  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1875  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1876  MaskV);
1877  return RValue::get(Vec);
1878 }
1879 
1880 /// Generates lvalue for partial ext_vector access.
1882  Address VectorAddress = LV.getExtVectorAddress();
1883  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1884  QualType EQT = ExprVT->getElementType();
1885  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1886 
1887  Address CastToPointerElement =
1888  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1889  "conv.ptr.element");
1890 
1891  const llvm::Constant *Elts = LV.getExtVectorElts();
1892  unsigned ix = getAccessedFieldNo(0, Elts);
1893 
1894  Address VectorBasePtrPlusIx =
1895  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1896  "vector.elt");
1897 
1898  return VectorBasePtrPlusIx;
1899 }
1900 
1901 /// Load of global gamed gegisters are always calls to intrinsics.
1903  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1904  "Bad type for register variable");
1905  llvm::MDNode *RegName = cast<llvm::MDNode>(
1906  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1907 
1908  // We accept integer and pointer types only
1909  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1910  llvm::Type *Ty = OrigTy;
1911  if (OrigTy->isPointerTy())
1912  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1913  llvm::Type *Types[] = { Ty };
1914 
1915  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1916  llvm::Value *Call = Builder.CreateCall(
1917  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1918  if (OrigTy->isPointerTy())
1919  Call = Builder.CreateIntToPtr(Call, OrigTy);
1920  return RValue::get(Call);
1921 }
1922 
1923 
1924 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1925 /// lvalue, where both are guaranteed to the have the same type, and that type
1926 /// is 'Ty'.
1928  bool isInit) {
1929  if (!Dst.isSimple()) {
1930  if (Dst.isVectorElt()) {
1931  // Read/modify/write the vector, inserting the new element.
1933  Dst.isVolatileQualified());
1934  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1935  Dst.getVectorIdx(), "vecins");
1937  Dst.isVolatileQualified());
1938  return;
1939  }
1940 
1941  // If this is an update of extended vector elements, insert them as
1942  // appropriate.
1943  if (Dst.isExtVectorElt())
1945 
1946  if (Dst.isGlobalReg())
1947  return EmitStoreThroughGlobalRegLValue(Src, Dst);
1948 
1949  assert(Dst.isBitField() && "Unknown LValue type");
1950  return EmitStoreThroughBitfieldLValue(Src, Dst);
1951  }
1952 
1953  // There's special magic for assigning into an ARC-qualified l-value.
1954  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1955  switch (Lifetime) {
1956  case Qualifiers::OCL_None:
1957  llvm_unreachable("present but none");
1958 
1960  // nothing special
1961  break;
1962 
1964  if (isInit) {
1965  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1966  break;
1967  }
1968  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1969  return;
1970 
1971  case Qualifiers::OCL_Weak:
1972  if (isInit)
1973  // Initialize and then skip the primitive store.
1974  EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1975  else
1976  EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1977  return;
1978 
1981  Src.getScalarVal()));
1982  // fall into the normal path
1983  break;
1984  }
1985  }
1986 
1987  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1988  // load of a __weak object.
1989  Address LvalueDst = Dst.getAddress();
1990  llvm::Value *src = Src.getScalarVal();
1991  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1992  return;
1993  }
1994 
1995  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1996  // load of a __strong object.
1997  Address LvalueDst = Dst.getAddress();
1998  llvm::Value *src = Src.getScalarVal();
1999  if (Dst.isObjCIvar()) {
2000  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2001  llvm::Type *ResultType = IntPtrTy;
2003  llvm::Value *RHS = dst.getPointer();
2004  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2005  llvm::Value *LHS =
2006  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2007  "sub.ptr.lhs.cast");
2008  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2009  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2010  BytesBetween);
2011  } else if (Dst.isGlobalObjCRef()) {
2012  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2013  Dst.isThreadLocalRef());
2014  }
2015  else
2016  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2017  return;
2018  }
2019 
2020  assert(Src.isScalar() && "Can't emit an agg store with this method");
2021  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2022 }
2023 
2025  llvm::Value **Result) {
2026  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2027  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2028  Address Ptr = Dst.getBitFieldAddress();
2029 
2030  // Get the source value, truncated to the width of the bit-field.
2031  llvm::Value *SrcVal = Src.getScalarVal();
2032 
2033  // Cast the source to the storage type and shift it into place.
2034  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2035  /*isSigned=*/false);
2036  llvm::Value *MaskedVal = SrcVal;
2037 
2038  // See if there are other bits in the bitfield's storage we'll need to load
2039  // and mask together with source before storing.
2040  if (Info.StorageSize != Info.Size) {
2041  assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
2042  llvm::Value *Val =
2043  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2044 
2045  // Mask the source value as needed.
2046  if (!hasBooleanRepresentation(Dst.getType()))
2047  SrcVal = Builder.CreateAnd(SrcVal,
2048  llvm::APInt::getLowBitsSet(Info.StorageSize,
2049  Info.Size),
2050  "bf.value");
2051  MaskedVal = SrcVal;
2052  if (Info.Offset)
2053  SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
2054 
2055  // Mask out the original value.
2056  Val = Builder.CreateAnd(Val,
2057  ~llvm::APInt::getBitsSet(Info.StorageSize,
2058  Info.Offset,
2059  Info.Offset + Info.Size),
2060  "bf.clear");
2061 
2062  // Or together the unchanged values and the source value.
2063  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2064  } else {
2065  assert(Info.Offset == 0);
2066  }
2067 
2068  // Write the new value back out.
2069  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2070 
2071  // Return the new value of the bit-field, if requested.
2072  if (Result) {
2073  llvm::Value *ResultVal = MaskedVal;
2074 
2075  // Sign extend the value if needed.
2076  if (Info.IsSigned) {
2077  assert(Info.Size <= Info.StorageSize);
2078  unsigned HighBits = Info.StorageSize - Info.Size;
2079  if (HighBits) {
2080  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2081  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2082  }
2083  }
2084 
2085  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2086  "bf.result.cast");
2087  *Result = EmitFromMemory(ResultVal, Dst.getType());
2088  }
2089 }
2090 
2092  LValue Dst) {
2093  // This access turns into a read/modify/write of the vector. Load the input
2094  // value now.
2096  Dst.isVolatileQualified());
2097  const llvm::Constant *Elts = Dst.getExtVectorElts();
2098 
2099  llvm::Value *SrcVal = Src.getScalarVal();
2100 
2101  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2102  unsigned NumSrcElts = VTy->getNumElements();
2103  unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2104  if (NumDstElts == NumSrcElts) {
2105  // Use shuffle vector is the src and destination are the same number of
2106  // elements and restore the vector mask since it is on the side it will be
2107  // stored.
2108  SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2109  for (unsigned i = 0; i != NumSrcElts; ++i)
2110  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2111 
2112  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2113  Vec = Builder.CreateShuffleVector(SrcVal,
2114  llvm::UndefValue::get(Vec->getType()),
2115  MaskV);
2116  } else if (NumDstElts > NumSrcElts) {
2117  // Extended the source vector to the same length and then shuffle it
2118  // into the destination.
2119  // FIXME: since we're shuffling with undef, can we just use the indices
2120  // into that? This could be simpler.
2122  for (unsigned i = 0; i != NumSrcElts; ++i)
2123  ExtMask.push_back(Builder.getInt32(i));
2124  ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2125  llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2126  llvm::Value *ExtSrcVal =
2127  Builder.CreateShuffleVector(SrcVal,
2128  llvm::UndefValue::get(SrcVal->getType()),
2129  ExtMaskV);
2130  // build identity
2132  for (unsigned i = 0; i != NumDstElts; ++i)
2133  Mask.push_back(Builder.getInt32(i));
2134 
2135  // When the vector size is odd and .odd or .hi is used, the last element
2136  // of the Elts constant array will be one past the size of the vector.
2137  // Ignore the last element here, if it is greater than the mask size.
2138  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2139  NumSrcElts--;
2140 
2141  // modify when what gets shuffled in
2142  for (unsigned i = 0; i != NumSrcElts; ++i)
2143  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2144  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2145  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2146  } else {
2147  // We should never shorten the vector
2148  llvm_unreachable("unexpected shorten vector length");
2149  }
2150  } else {
2151  // If the Src is a scalar (not a vector) it must be updating one element.
2152  unsigned InIdx = getAccessedFieldNo(0, Elts);
2153  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2154  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2155  }
2156 
2158  Dst.isVolatileQualified());
2159 }
2160 
2161 /// Store of global named registers are always calls to intrinsics.
2163  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2164  "Bad type for register variable");
2165  llvm::MDNode *RegName = cast<llvm::MDNode>(
2166  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2167  assert(RegName && "Register LValue is not metadata");
2168 
2169  // We accept integer and pointer types only
2170  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2171  llvm::Type *Ty = OrigTy;
2172  if (OrigTy->isPointerTy())
2173  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2174  llvm::Type *Types[] = { Ty };
2175 
2176  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2177  llvm::Value *Value = Src.getScalarVal();
2178  if (OrigTy->isPointerTy())
2179  Value = Builder.CreatePtrToInt(Value, Ty);
2180  Builder.CreateCall(
2181  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2182 }
2183 
2184 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2185 // generating write-barries API. It is currently a global, ivar,
2186 // or neither.
2187 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2188  LValue &LV,
2189  bool IsMemberAccess=false) {
2190  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2191  return;
2192 
2193  if (isa<ObjCIvarRefExpr>(E)) {
2194  QualType ExpTy = E->getType();
2195  if (IsMemberAccess && ExpTy->isPointerType()) {
2196  // If ivar is a structure pointer, assigning to field of
2197  // this struct follows gcc's behavior and makes it a non-ivar
2198  // writer-barrier conservatively.
2199  ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2200  if (ExpTy->isRecordType()) {
2201  LV.setObjCIvar(false);
2202  return;
2203  }
2204  }
2205  LV.setObjCIvar(true);
2206  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2207  LV.setBaseIvarExp(Exp->getBase());
2208  LV.setObjCArray(E->getType()->isArrayType());
2209  return;
2210  }
2211 
2212  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2213  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2214  if (VD->hasGlobalStorage()) {
2215  LV.setGlobalObjCRef(true);
2216  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2217  }
2218  }
2219  LV.setObjCArray(E->getType()->isArrayType());
2220  return;
2221  }
2222 
2223  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2224  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2225  return;
2226  }
2227 
2228  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2229  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2230  if (LV.isObjCIvar()) {
2231  // If cast is to a structure pointer, follow gcc's behavior and make it
2232  // a non-ivar write-barrier.
2233  QualType ExpTy = E->getType();
2234  if (ExpTy->isPointerType())
2235  ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2236  if (ExpTy->isRecordType())
2237  LV.setObjCIvar(false);
2238  }
2239  return;
2240  }
2241 
2242  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2243  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2244  return;
2245  }
2246 
2247  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2248  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2249  return;
2250  }
2251 
2252  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2253  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2254  return;
2255  }
2256 
2257  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2258  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2259  return;
2260  }
2261 
2262  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2263  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2264  if (LV.isObjCIvar() && !LV.isObjCArray())
2265  // Using array syntax to assigning to what an ivar points to is not
2266  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2267  LV.setObjCIvar(false);
2268  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2269  // Using array syntax to assigning to what global points to is not
2270  // same as assigning to the global itself. {id *G;} G[i] = 0;
2271  LV.setGlobalObjCRef(false);
2272  return;
2273  }
2274 
2275  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2276  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2277  // We don't know if member is an 'ivar', but this flag is looked at
2278  // only in the context of LV.isObjCIvar().
2279  LV.setObjCArray(E->getType()->isArrayType());
2280  return;
2281  }
2282 }
2283 
2284 static llvm::Value *
2286  llvm::Value *V, llvm::Type *IRType,
2287  StringRef Name = StringRef()) {
2288  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2289  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2290 }
2291 
2293  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2294  llvm::Type *RealVarTy, SourceLocation Loc) {
2295  Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2296  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2297  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2298 }
2299 
2301  const VarDecl *VD, QualType T) {
2303  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2304  // Return an invalid address if variable is MT_To and unified
2305  // memory is not enabled. For all other cases: MT_Link and
2306  // MT_To with unified memory, return a valid address.
2307  if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2308  !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2309  return Address::invalid();
2310  assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2311  (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2312  CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2313  "Expected link clause OR to clause with unified memory enabled.");
2314  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2315  Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2316  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2317 }
2318 
2319 Address
2321  LValueBaseInfo *PointeeBaseInfo,
2322  TBAAAccessInfo *PointeeTBAAInfo) {
2323  llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2324  RefLVal.isVolatile());
2325  CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2326 
2328  PointeeBaseInfo, PointeeTBAAInfo,
2329  /* forPointeeType= */ true);
2330  return Address(Load, Align);
2331 }
2332 
2334  LValueBaseInfo PointeeBaseInfo;
2335  TBAAAccessInfo PointeeTBAAInfo;
2336  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2337  &PointeeTBAAInfo);
2338  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2339  PointeeBaseInfo, PointeeTBAAInfo);
2340 }
2341 
2343  const PointerType *PtrTy,
2344  LValueBaseInfo *BaseInfo,
2345  TBAAAccessInfo *TBAAInfo) {
2346  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2347  return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2348  BaseInfo, TBAAInfo,
2349  /*forPointeeType=*/true));
2350 }
2351 
2353  const PointerType *PtrTy) {
2354  LValueBaseInfo BaseInfo;
2355  TBAAAccessInfo TBAAInfo;
2356  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2357  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2358 }
2359 
2361  const Expr *E, const VarDecl *VD) {
2362  QualType T = E->getType();
2363 
2364  // If it's thread_local, emit a call to its wrapper function instead.
2365  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2367  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2368  // Check if the variable is marked as declare target with link clause in
2369  // device codegen.
2370  if (CGF.getLangOpts().OpenMPIsDevice) {
2371  Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2372  if (Addr.isValid())
2373  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2374  }
2375 
2376  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2377  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2378  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2379  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2380  Address Addr(V, Alignment);
2381  // Emit reference to the private copy of the variable if it is an OpenMP
2382  // threadprivate variable.
2383  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2384  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2385  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2386  E->getExprLoc());
2387  }
2388  LValue LV = VD->getType()->isReferenceType() ?
2389  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2391  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2392  setObjCGCLValueClass(CGF.getContext(), E, LV);
2393  return LV;
2394 }
2395 
2397  const FunctionDecl *FD) {
2398  if (FD->hasAttr<WeakRefAttr>()) {
2399  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2400  return aliasee.getPointer();
2401  }
2402 
2403  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2404  if (!FD->hasPrototype()) {
2405  if (const FunctionProtoType *Proto =
2406  FD->getType()->getAs<FunctionProtoType>()) {
2407  // Ugly case: for a K&R-style definition, the type of the definition
2408  // isn't the same as the type of a use. Correct for this with a
2409  // bitcast.
2410  QualType NoProtoType =
2411  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2412  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2413  V = llvm::ConstantExpr::getBitCast(V,
2414  CGM.getTypes().ConvertType(NoProtoType));
2415  }
2416  }
2417  return V;
2418 }
2419 
2421  const Expr *E, const FunctionDecl *FD) {
2422  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2423  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2424  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2426 }
2427 
2429  llvm::Value *ThisValue) {
2431  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2432  return CGF.EmitLValueForField(LV, FD);
2433 }
2434 
2435 /// Named Registers are named metadata pointing to the register name
2436 /// which will be read from/written to as an argument to the intrinsic
2437 /// @llvm.read/write_register.
2438 /// So far, only the name is being passed down, but other options such as
2439 /// register type, allocation type or even optimization options could be
2440 /// passed down via the metadata node.
2442  SmallString<64> Name("llvm.named.register.");
2443  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2444  assert(Asm->getLabel().size() < 64-Name.size() &&
2445  "Register name too big");
2446  Name.append(Asm->getLabel());
2447  llvm::NamedMDNode *M =
2448  CGM.getModule().getOrInsertNamedMetadata(Name);
2449  if (M->getNumOperands() == 0) {
2450  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2451  Asm->getLabel());
2452  llvm::Metadata *Ops[] = {Str};
2453  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2454  }
2455 
2456  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2457 
2458  llvm::Value *Ptr =
2459  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2460  return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2461 }
2462 
2463 /// Determine whether we can emit a reference to \p VD from the current
2464 /// context, despite not necessarily having seen an odr-use of the variable in
2465 /// this context.
2467  const DeclRefExpr *E,
2468  const VarDecl *VD,
2469  bool IsConstant) {
2470  // For a variable declared in an enclosing scope, do not emit a spurious
2471  // reference even if we have a capture, as that will emit an unwarranted
2472  // reference to our capture state, and will likely generate worse code than
2473  // emitting a local copy.
2475  return false;
2476 
2477  // For a local declaration declared in this function, we can always reference
2478  // it even if we don't have an odr-use.
2479  if (VD->hasLocalStorage()) {
2480  return VD->getDeclContext() ==
2481  dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2482  }
2483 
2484  // For a global declaration, we can emit a reference to it if we know
2485  // for sure that we are able to emit a definition of it.
2486  VD = VD->getDefinition(CGF.getContext());
2487  if (!VD)
2488  return false;
2489 
2490  // Don't emit a spurious reference if it might be to a variable that only
2491  // exists on a different device / target.
2492  // FIXME: This is unnecessarily broad. Check whether this would actually be a
2493  // cross-target reference.
2494  if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2495  CGF.getLangOpts().OpenCL) {
2496  return false;
2497  }
2498 
2499  // We can emit a spurious reference only if the linkage implies that we'll
2500  // be emitting a non-interposable symbol that will be retained until link
2501  // time.
2502  switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2504  case llvm::GlobalValue::LinkOnceODRLinkage:
2505  case llvm::GlobalValue::WeakODRLinkage:
2507  case llvm::GlobalValue::PrivateLinkage:
2508  return true;
2509  default:
2510  return false;
2511  }
2512 }
2513 
2515  const NamedDecl *ND = E->getDecl();
2516  QualType T = E->getType();
2517 
2518  assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2519  "should not emit an unevaluated operand");
2520 
2521  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2522  // Global Named registers access via intrinsics only
2523  if (VD->getStorageClass() == SC_Register &&
2524  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2525  return EmitGlobalNamedRegister(VD, CGM);
2526 
2527  // If this DeclRefExpr does not constitute an odr-use of the variable,
2528  // we're not permitted to emit a reference to it in general, and it might
2529  // not be captured if capture would be necessary for a use. Emit the
2530  // constant value directly instead.
2531  if (E->isNonOdrUse() == NOUR_Constant &&
2532  (VD->getType()->isReferenceType() ||
2533  !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2534  VD->getAnyInitializer(VD);
2535  llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2536  E->getLocation(), *VD->evaluateValue(), VD->getType());
2537  assert(Val && "failed to emit constant expression");
2538 
2539  Address Addr = Address::invalid();
2540  if (!VD->getType()->isReferenceType()) {
2541  // Spill the constant value to a global.
2542  Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2543  getContext().getDeclAlign(VD));
2544  llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
2545  auto *PTy = llvm::PointerType::get(
2546  VarTy, getContext().getTargetAddressSpace(VD->getType()));
2547  if (PTy != Addr.getType())
2548  Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy);
2549  } else {
2550  // Should we be using the alignment of the constant pointer we emitted?
2551  CharUnits Alignment =
2553  /* BaseInfo= */ nullptr,
2554  /* TBAAInfo= */ nullptr,
2555  /* forPointeeType= */ true);
2556  Addr = Address(Val, Alignment);
2557  }
2558  return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2559  }
2560 
2561  // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2562 
2563  // Check for captured variables.
2565  VD = VD->getCanonicalDecl();
2566  if (auto *FD = LambdaCaptureFields.lookup(VD))
2567  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2568  else if (CapturedStmtInfo) {
2569  auto I = LocalDeclMap.find(VD);
2570  if (I != LocalDeclMap.end()) {
2571  if (VD->getType()->isReferenceType())
2572  return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2574  return MakeAddrLValue(I->second, T);
2575  }
2576  LValue CapLVal =
2579  return MakeAddrLValue(
2580  Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2582  CapLVal.getTBAAInfo());
2583  }
2584 
2585  assert(isa<BlockDecl>(CurCodeDecl));
2586  Address addr = GetAddrOfBlockDecl(VD);
2587  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2588  }
2589  }
2590 
2591  // FIXME: We should be able to assert this for FunctionDecls as well!
2592  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2593  // those with a valid source location.
2594  assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2595  !E->getLocation().isValid()) &&
2596  "Should not use decl without marking it used!");
2597 
2598  if (ND->hasAttr<WeakRefAttr>()) {
2599  const auto *VD = cast<ValueDecl>(ND);
2600  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2601  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2602  }
2603 
2604  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2605  // Check if this is a global variable.
2606  if (VD->hasLinkage() || VD->isStaticDataMember())
2607  return EmitGlobalVarDeclLValue(*this, E, VD);
2608 
2609  Address addr = Address::invalid();
2610 
2611  // The variable should generally be present in the local decl map.
2612  auto iter = LocalDeclMap.find(VD);
2613  if (iter != LocalDeclMap.end()) {
2614  addr = iter->second;
2615 
2616  // Otherwise, it might be static local we haven't emitted yet for
2617  // some reason; most likely, because it's in an outer function.
2618  } else if (VD->isStaticLocal()) {
2620  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false)),
2621  getContext().getDeclAlign(VD));
2622 
2623  // No other cases for now.
2624  } else {
2625  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2626  }
2627 
2628 
2629  // Check for OpenMP threadprivate variables.
2630  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2631  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2633  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2634  E->getExprLoc());
2635  }
2636 
2637  // Drill into block byref variables.
2638  bool isBlockByref = VD->isEscapingByref();
2639  if (isBlockByref) {
2640  addr = emitBlockByrefAddress(addr, VD);
2641  }
2642 
2643  // Drill into reference types.
2644  LValue LV = VD->getType()->isReferenceType() ?
2647 
2648  bool isLocalStorage = VD->hasLocalStorage();
2649 
2650  bool NonGCable = isLocalStorage &&
2651  !VD->getType()->isReferenceType() &&
2652  !isBlockByref;
2653  if (NonGCable) {
2654  LV.getQuals().removeObjCGCAttr();
2655  LV.setNonGC(true);
2656  }
2657 
2658  bool isImpreciseLifetime =
2659  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2660  if (isImpreciseLifetime)
2662  setObjCGCLValueClass(getContext(), E, LV);
2663  return LV;
2664  }
2665 
2666  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2667  return EmitFunctionDeclLValue(*this, E, FD);
2668 
2669  // FIXME: While we're emitting a binding from an enclosing scope, all other
2670  // DeclRefExprs we see should be implicitly treated as if they also refer to
2671  // an enclosing scope.
2672  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2673  return EmitLValue(BD->getBinding());
2674 
2675  llvm_unreachable("Unhandled DeclRefExpr");
2676 }
2677 
2679  // __extension__ doesn't affect lvalue-ness.
2680  if (E->getOpcode() == UO_Extension)
2681  return EmitLValue(E->getSubExpr());
2682 
2684  switch (E->getOpcode()) {
2685  default: llvm_unreachable("Unknown unary operator lvalue!");
2686  case UO_Deref: {
2687  QualType T = E->getSubExpr()->getType()->getPointeeType();
2688  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2689 
2690  LValueBaseInfo BaseInfo;
2691  TBAAAccessInfo TBAAInfo;
2692  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2693  &TBAAInfo);
2694  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2695  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2696 
2697  // We should not generate __weak write barrier on indirect reference
2698  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2699  // But, we continue to generate __strong write barrier on indirect write
2700  // into a pointer to object.
2701  if (getLangOpts().ObjC &&
2702  getLangOpts().getGC() != LangOptions::NonGC &&
2703  LV.isObjCWeak())
2704  LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2705  return LV;
2706  }
2707  case UO_Real:
2708  case UO_Imag: {
2709  LValue LV = EmitLValue(E->getSubExpr());
2710  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2711 
2712  // __real is valid on scalars. This is a faster way of testing that.
2713  // __imag can only produce an rvalue on scalars.
2714  if (E->getOpcode() == UO_Real &&
2715  !LV.getAddress().getElementType()->isStructTy()) {
2716  assert(E->getSubExpr()->getType()->isArithmeticType());
2717  return LV;
2718  }
2719 
2720  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2721 
2722  Address Component =
2723  (E->getOpcode() == UO_Real
2726  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2727  CGM.getTBAAInfoForSubobject(LV, T));
2728  ElemLV.getQuals().addQualifiers(LV.getQuals());
2729  return ElemLV;
2730  }
2731  case UO_PreInc:
2732  case UO_PreDec: {
2733  LValue LV = EmitLValue(E->getSubExpr());
2734  bool isInc = E->getOpcode() == UO_PreInc;
2735 
2736  if (E->getType()->isAnyComplexType())
2737  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2738  else
2739  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2740  return LV;
2741  }
2742  }
2743 }
2744 
2748 }
2749 
2753 }
2754 
2756  auto SL = E->getFunctionName();
2757  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2758  StringRef FnName = CurFn->getName();
2759  if (FnName.startswith("\01"))
2760  FnName = FnName.substr(1);
2761  StringRef NameItems[] = {
2763  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2764  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2765  std::string Name = SL->getString();
2766  if (!Name.empty()) {
2767  unsigned Discriminator =
2768  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2769  if (Discriminator)
2770  Name += "_" + Twine(Discriminator + 1).str();
2771  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2772  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2773  } else {
2774  auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2775  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2776  }
2777  }
2778  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2779  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2780 }
2781 
2782 /// Emit a type description suitable for use by a runtime sanitizer library. The
2783 /// format of a type descriptor is
2784 ///
2785 /// \code
2786 /// { i16 TypeKind, i16 TypeInfo }
2787 /// \endcode
2788 ///
2789 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2790 /// integer, 1 for a floating point value, and -1 for anything else.
2792  // Only emit each type's descriptor once.
2793  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2794  return C;
2795 
2796  uint16_t TypeKind = -1;
2797  uint16_t TypeInfo = 0;
2798 
2799  if (T->isIntegerType()) {
2800  TypeKind = 0;
2801  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2802  (T->isSignedIntegerType() ? 1 : 0);
2803  } else if (T->isFloatingType()) {
2804  TypeKind = 1;
2805  TypeInfo = getContext().getTypeSize(T);
2806  }
2807 
2808  // Format the type name as if for a diagnostic, including quotes and
2809  // optionally an 'aka'.
2810  SmallString<32> Buffer;
2812  (intptr_t)T.getAsOpaquePtr(),
2813  StringRef(), StringRef(), None, Buffer,
2814  None);
2815 
2816  llvm::Constant *Components[] = {
2817  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2818  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2819  };
2820  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2821 
2822  auto *GV = new llvm::GlobalVariable(
2823  CGM.getModule(), Descriptor->getType(),
2824  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2825  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2827 
2828  // Remember the descriptor for this type.
2829  CGM.setTypeDescriptorInMap(T, GV);
2830 
2831  return GV;
2832 }
2833 
2835  llvm::Type *TargetTy = IntPtrTy;
2836 
2837  if (V->getType() == TargetTy)
2838  return V;
2839 
2840  // Floating-point types which fit into intptr_t are bitcast to integers
2841  // and then passed directly (after zero-extension, if necessary).
2842  if (V->getType()->isFloatingPointTy()) {
2843  unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2844  if (Bits <= TargetTy->getIntegerBitWidth())
2845  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2846  Bits));
2847  }
2848 
2849  // Integers which fit in intptr_t are zero-extended and passed directly.
2850  if (V->getType()->isIntegerTy() &&
2851  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2852  return Builder.CreateZExt(V, TargetTy);
2853 
2854  // Pointers are passed directly, everything else is passed by address.
2855  if (!V->getType()->isPointerTy()) {
2856  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2857  Builder.CreateStore(V, Ptr);
2858  V = Ptr.getPointer();
2859  }
2860  return Builder.CreatePtrToInt(V, TargetTy);
2861 }
2862 
2863 /// Emit a representation of a SourceLocation for passing to a handler
2864 /// in a sanitizer runtime library. The format for this data is:
2865 /// \code
2866 /// struct SourceLocation {
2867 /// const char *Filename;
2868 /// int32_t Line, Column;
2869 /// };
2870 /// \endcode
2871 /// For an invalid SourceLocation, the Filename pointer is null.
2873  llvm::Constant *Filename;
2874  int Line, Column;
2875 
2877  if (PLoc.isValid()) {
2878  StringRef FilenameString = PLoc.getFilename();
2879 
2880  int PathComponentsToStrip =
2881  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2882  if (PathComponentsToStrip < 0) {
2883  assert(PathComponentsToStrip != INT_MIN);
2884  int PathComponentsToKeep = -PathComponentsToStrip;
2885  auto I = llvm::sys::path::rbegin(FilenameString);
2886  auto E = llvm::sys::path::rend(FilenameString);
2887  while (I != E && --PathComponentsToKeep)
2888  ++I;
2889 
2890  FilenameString = FilenameString.substr(I - E);
2891  } else if (PathComponentsToStrip > 0) {
2892  auto I = llvm::sys::path::begin(FilenameString);
2893  auto E = llvm::sys::path::end(FilenameString);
2894  while (I != E && PathComponentsToStrip--)
2895  ++I;
2896 
2897  if (I != E)
2898  FilenameString =
2899  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2900  else
2901  FilenameString = llvm::sys::path::filename(FilenameString);
2902  }
2903 
2904  auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2906  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2907  Filename = FilenameGV.getPointer();
2908  Line = PLoc.getLine();
2909  Column = PLoc.getColumn();
2910  } else {
2911  Filename = llvm::Constant::getNullValue(Int8PtrTy);
2912  Line = Column = 0;
2913  }
2914 
2915  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2916  Builder.getInt32(Column)};
2917 
2918  return llvm::ConstantStruct::getAnon(Data);
2919 }
2920 
2921 namespace {
2922 /// Specify under what conditions this check can be recovered
2924  /// Always terminate program execution if this check fails.
2925  Unrecoverable,
2926  /// Check supports recovering, runtime has both fatal (noreturn) and
2927  /// non-fatal handlers for this check.
2928  Recoverable,
2929  /// Runtime conditionally aborts, always need to support recovery.
2931 };
2932 }
2933 
2935  assert(Kind.countPopulation() == 1);
2936  if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
2938  else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
2940  else
2941  return CheckRecoverableKind::Recoverable;
2942 }
2943 
2944 namespace {
2945 struct SanitizerHandlerInfo {
2946  char const *const Name;
2947  unsigned Version;
2948 };
2949 }
2950 
2951 const SanitizerHandlerInfo SanitizerHandlers[] = {
2952 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2954 #undef SANITIZER_CHECK
2955 };
2956 
2958  llvm::FunctionType *FnType,
2959  ArrayRef<llvm::Value *> FnArgs,
2960  SanitizerHandler CheckHandler,
2961  CheckRecoverableKind RecoverKind, bool IsFatal,
2962  llvm::BasicBlock *ContBB) {
2963  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2965  if (!CGF.Builder.getCurrentDebugLocation()) {
2966  // Ensure that the call has at least an artificial debug location.
2967  DL.emplace(CGF, SourceLocation());
2968  }
2969  bool NeedsAbortSuffix =
2970  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2971  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2972  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2973  const StringRef CheckName = CheckInfo.Name;
2974  std::string FnName = "__ubsan_handle_" + CheckName.str();
2975  if (CheckInfo.Version && !MinimalRuntime)
2976  FnName += "_v" + llvm::utostr(CheckInfo.Version);
2977  if (MinimalRuntime)
2978  FnName += "_minimal";
2979  if (NeedsAbortSuffix)
2980  FnName += "_abort";
2981  bool MayReturn =
2982  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2983 
2984  llvm::AttrBuilder B;
2985  if (!MayReturn) {
2986  B.addAttribute(llvm::Attribute::NoReturn)
2987  .addAttribute(llvm::Attribute::NoUnwind);
2988  }
2989  B.addAttribute(llvm::Attribute::UWTable);
2990 
2991  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
2992  FnType, FnName,
2993  llvm::AttributeList::get(CGF.getLLVMContext(),
2994  llvm::AttributeList::FunctionIndex, B),
2995  /*Local=*/true);
2996  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2997  if (!MayReturn) {
2998  HandlerCall->setDoesNotReturn();
2999  CGF.Builder.CreateUnreachable();
3000  } else {
3001  CGF.Builder.CreateBr(ContBB);
3002  }
3003 }
3004 
3006  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3007  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3008  ArrayRef<llvm::Value *> DynamicArgs) {
3009  assert(IsSanitizerScope);
3010  assert(Checked.size() > 0);
3011  assert(CheckHandler >= 0 &&
3012  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3013  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3014 
3015  llvm::Value *FatalCond = nullptr;
3016  llvm::Value *RecoverableCond = nullptr;
3017  llvm::Value *TrapCond = nullptr;
3018  for (int i = 0, n = Checked.size(); i < n; ++i) {
3019  llvm::Value *Check = Checked[i].first;
3020  // -fsanitize-trap= overrides -fsanitize-recover=.
3021  llvm::Value *&Cond =
3022  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3023  ? TrapCond
3024  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3025  ? RecoverableCond
3026  : FatalCond;
3027  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3028  }
3029 
3030  if (TrapCond)
3031  EmitTrapCheck(TrapCond);
3032  if (!FatalCond && !RecoverableCond)
3033  return;
3034 
3035  llvm::Value *JointCond;
3036  if (FatalCond && RecoverableCond)
3037  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3038  else
3039  JointCond = FatalCond ? FatalCond : RecoverableCond;
3040  assert(JointCond);
3041 
3042  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3043  assert(SanOpts.has(Checked[0].second));
3044 #ifndef NDEBUG
3045  for (int i = 1, n = Checked.size(); i < n; ++i) {
3046  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3047  "All recoverable kinds in a single check must be same!");
3048  assert(SanOpts.has(Checked[i].second));
3049  }
3050 #endif
3051 
3052  llvm::BasicBlock *Cont = createBasicBlock("cont");
3053  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3054  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3055  // Give hint that we very much don't expect to execute the handler
3056  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3057  llvm::MDBuilder MDHelper(getLLVMContext());
3058  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3059  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3060  EmitBlock(Handlers);
3061 
3062  // Handler functions take an i8* pointing to the (handler-specific) static
3063  // information block, followed by a sequence of intptr_t arguments
3064  // representing operand values.
3067  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3068  Args.reserve(DynamicArgs.size() + 1);
3069  ArgTypes.reserve(DynamicArgs.size() + 1);
3070 
3071  // Emit handler arguments and create handler function type.
3072  if (!StaticArgs.empty()) {
3073  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3074  auto *InfoPtr =
3075  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3076  llvm::GlobalVariable::PrivateLinkage, Info);
3077  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3079  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3080  ArgTypes.push_back(Int8PtrTy);
3081  }
3082 
3083  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3084  Args.push_back(EmitCheckValue(DynamicArgs[i]));
3085  ArgTypes.push_back(IntPtrTy);
3086  }
3087  }
3088 
3089  llvm::FunctionType *FnType =
3090  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3091 
3092  if (!FatalCond || !RecoverableCond) {
3093  // Simple case: we need to generate a single handler call, either
3094  // fatal, or non-fatal.
3095  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3096  (FatalCond != nullptr), Cont);
3097  } else {
3098  // Emit two handler calls: first one for set of unrecoverable checks,
3099  // another one for recoverable.
3100  llvm::BasicBlock *NonFatalHandlerBB =
3101  createBasicBlock("non_fatal." + CheckName);
3102  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3103  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3104  EmitBlock(FatalHandlerBB);
3105  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3106  NonFatalHandlerBB);
3107  EmitBlock(NonFatalHandlerBB);
3108  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3109  Cont);
3110  }
3111 
3112  EmitBlock(Cont);
3113 }
3114 
3116  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3117  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3118  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3119 
3120  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3121  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3122 
3123  llvm::MDBuilder MDHelper(getLLVMContext());
3124  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3125  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3126 
3127  EmitBlock(CheckBB);
3128 
3129  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3130 
3131  llvm::CallInst *CheckCall;
3132  llvm::FunctionCallee SlowPathFn;
3133  if (WithDiag) {
3134  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3135  auto *InfoPtr =
3136  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3137  llvm::GlobalVariable::PrivateLinkage, Info);
3138  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3140 
3141  SlowPathFn = CGM.getModule().getOrInsertFunction(
3142  "__cfi_slowpath_diag",
3143  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3144  false));
3145  CheckCall = Builder.CreateCall(
3146  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3147  } else {
3148  SlowPathFn = CGM.getModule().getOrInsertFunction(
3149  "__cfi_slowpath",
3150  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3151  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3152  }
3153 
3154  CGM.setDSOLocal(
3155  cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3156  CheckCall->setDoesNotThrow();
3157 
3158  EmitBlock(Cont);
3159 }
3160 
3161 // Emit a stub for __cfi_check function so that the linker knows about this
3162 // symbol in LTO mode.
3164  llvm::Module *M = &CGM.getModule();
3165  auto &Ctx = M->getContext();
3166  llvm::Function *F = llvm::Function::Create(
3167  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3168  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3169  CGM.setDSOLocal(F);
3170  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3171  // FIXME: consider emitting an intrinsic call like
3172  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3173  // which can be lowered in CrossDSOCFI pass to the actual contents of
3174  // __cfi_check. This would allow inlining of __cfi_check calls.
3176  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3177  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3178 }
3179 
3180 // This function is basically a switch over the CFI failure kind, which is
3181 // extracted from CFICheckFailData (1st function argument). Each case is either
3182 // llvm.trap or a call to one of the two runtime handlers, based on
3183 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3184 // failure kind) traps, but this should really never happen. CFICheckFailData
3185 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3186 // check kind; in this case __cfi_check_fail traps as well.
3188  SanitizerScope SanScope(this);
3189  FunctionArgList Args;
3194  Args.push_back(&ArgData);
3195  Args.push_back(&ArgAddr);
3196 
3197  const CGFunctionInfo &FI =
3199 
3200  llvm::Function *F = llvm::Function::Create(
3201  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3202  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3203  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3204 
3205  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3206  SourceLocation());
3207 
3208  // This function should not be affected by blacklist. This function does
3209  // not have a source location, but "src:*" would still apply. Revert any
3210  // changes to SanOpts made in StartFunction.
3212 
3213  llvm::Value *Data =
3214  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3215  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3216  llvm::Value *Addr =
3217  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3218  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3219 
3220  // Data == nullptr means the calling module has trap behaviour for this check.
3221  llvm::Value *DataIsNotNullPtr =
3222  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3223  EmitTrapCheck(DataIsNotNullPtr);
3224 
3225  llvm::StructType *SourceLocationTy =
3226  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3227  llvm::StructType *CfiCheckFailDataTy =
3228  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3229 
3230  llvm::Value *V = Builder.CreateConstGEP2_32(
3231  CfiCheckFailDataTy,
3232  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3233  0);
3234  Address CheckKindAddr(V, getIntAlign());
3235  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3236 
3237  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3238  CGM.getLLVMContext(),
3239  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3240  llvm::Value *ValidVtable = Builder.CreateZExt(
3241  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3242  {Addr, AllVtables}),
3243  IntPtrTy);
3244 
3245  const std::pair<int, SanitizerMask> CheckKinds[] = {
3246  {CFITCK_VCall, SanitizerKind::CFIVCall},
3247  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3248  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3249  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3250  {CFITCK_ICall, SanitizerKind::CFIICall}};
3251 
3253  for (auto CheckKindMaskPair : CheckKinds) {
3254  int Kind = CheckKindMaskPair.first;
3255  SanitizerMask Mask = CheckKindMaskPair.second;
3256  llvm::Value *Cond =
3257  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3258  if (CGM.getLangOpts().Sanitize.has(Mask))
3259  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3260  {Data, Addr, ValidVtable});
3261  else
3262  EmitTrapCheck(Cond);
3263  }
3264 
3265  FinishFunction();
3266  // The only reference to this function will be created during LTO link.
3267  // Make sure it survives until then.
3268  CGM.addUsedGlobal(F);
3269 }
3270 
3272  if (SanOpts.has(SanitizerKind::Unreachable)) {
3273  SanitizerScope SanScope(this);
3274  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3275  SanitizerKind::Unreachable),
3276  SanitizerHandler::BuiltinUnreachable,
3277  EmitCheckSourceLocation(Loc), None);
3278  }
3279  Builder.CreateUnreachable();
3280 }
3281 
3283  llvm::BasicBlock *Cont = createBasicBlock("cont");
3284 
3285  // If we're optimizing, collapse all calls to trap down to just one per
3286  // function to save on code size.
3287  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3288  TrapBB = createBasicBlock("trap");
3289  Builder.CreateCondBr(Checked, Cont, TrapBB);
3290  EmitBlock(TrapBB);
3291  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3292  TrapCall->setDoesNotReturn();
3293  TrapCall->setDoesNotThrow();
3294  Builder.CreateUnreachable();
3295  } else {
3296  Builder.CreateCondBr(Checked, Cont, TrapBB);
3297  }
3298 
3299  EmitBlock(Cont);
3300 }
3301 
3303  llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3304 
3305  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3306  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3308  TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3309  }
3310 
3311  return TrapCall;
3312 }
3313 
3315  LValueBaseInfo *BaseInfo,
3316  TBAAAccessInfo *TBAAInfo) {
3317  assert(E->getType()->isArrayType() &&
3318  "Array to pointer decay must have array source type!");
3319 
3320  // Expressions of array type can't be bitfields or vector elements.
3321  LValue LV = EmitLValue(E);
3322  Address Addr = LV.getAddress();
3323 
3324  // If the array type was an incomplete type, we need to make sure
3325  // the decay ends up being the right type.
3326  llvm::Type *NewTy = ConvertType(E->getType());
3327  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3328 
3329  // Note that VLA pointers are always decayed, so we don't need to do
3330  // anything here.
3331  if (!E->getType()->isVariableArrayType()) {
3332  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3333  "Expected pointer to array");
3334  Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3335  }
3336 
3337  // The result of this decay conversion points to an array element within the
3338  // base lvalue. However, since TBAA currently does not support representing
3339  // accesses to elements of member arrays, we conservatively represent accesses
3340  // to the pointee object as if it had no any base lvalue specified.
3341  // TODO: Support TBAA for member arrays.
3343  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3344  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3345 
3346  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3347 }
3348 
3349 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3350 /// array to pointer, return the array subexpression.
3351 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3352  // If this isn't just an array->pointer decay, bail out.
3353  const auto *CE = dyn_cast<CastExpr>(E);
3354  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3355  return nullptr;
3356 
3357  // If this is a decay from variable width array, bail out.
3358  const Expr *SubExpr = CE->getSubExpr();
3359  if (SubExpr->getType()->isVariableArrayType())
3360  return nullptr;
3361 
3362  return SubExpr;
3363 }
3364 
3366  llvm::Value *ptr,
3367  ArrayRef<llvm::Value*> indices,
3368  bool inbounds,
3369  bool signedIndices,
3370  SourceLocation loc,
3371  const llvm::Twine &name = "arrayidx") {
3372  if (inbounds) {
3373  return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3375  name);
3376  } else {
3377  return CGF.Builder.CreateGEP(ptr, indices, name);
3378  }
3379 }
3380 
3382  llvm::Value *idx,
3383  CharUnits eltSize) {
3384  // If we have a constant index, we can use the exact offset of the
3385  // element we're accessing.
3386  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3387  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3388  return arrayAlign.alignmentAtOffset(offset);
3389 
3390  // Otherwise, use the worst-case alignment for any element.
3391  } else {
3392  return arrayAlign.alignmentOfArrayElement(eltSize);
3393  }
3394 }
3395 
3397  const VariableArrayType *vla) {
3398  QualType eltType;
3399  do {
3400  eltType = vla->getElementType();
3401  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3402  return eltType;
3403 }
3404 
3406  ArrayRef<llvm::Value *> indices,
3407  QualType eltType, bool inbounds,
3408  bool signedIndices, SourceLocation loc,
3409  QualType *arrayType = nullptr,
3410  const llvm::Twine &name = "arrayidx") {
3411  // All the indices except that last must be zero.
3412 #ifndef NDEBUG
3413  for (auto idx : indices.drop_back())
3414  assert(isa<llvm::ConstantInt>(idx) &&
3415  cast<llvm::ConstantInt>(idx)->isZero());
3416 #endif
3417 
3418  // Determine the element size of the statically-sized base. This is
3419  // the thing that the indices are expressed in terms of.
3420  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3421  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3422  }
3423 
3424  // We can use that to compute the best alignment of the element.
3425  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3426  CharUnits eltAlign =
3427  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3428 
3429  llvm::Value *eltPtr;
3430  auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3431  if (!CGF.IsInPreservedAIRegion || !LastIndex) {
3432  eltPtr = emitArraySubscriptGEP(
3433  CGF, addr.getPointer(), indices, inbounds, signedIndices,
3434  loc, name);
3435  } else {
3436  // Remember the original array subscript for bpf target
3437  unsigned idx = LastIndex->getZExtValue();
3438  llvm::DIType *DbgInfo = nullptr;
3439  if (arrayType)
3440  DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
3441  eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getPointer(),
3442  indices.size() - 1,
3443  idx, DbgInfo);
3444  }
3445 
3446  return Address(eltPtr, eltAlign);
3447 }
3448 
3450  bool Accessed) {
3451  // The index must always be an integer, which is not an aggregate. Emit it
3452  // in lexical order (this complexity is, sadly, required by C++17).
3453  llvm::Value *IdxPre =
3454  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3455  bool SignedIndices = false;
3456  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3457  auto *Idx = IdxPre;
3458  if (E->getLHS() != E->getIdx()) {
3459  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3460  Idx = EmitScalarExpr(E->getIdx());
3461  }
3462 
3463  QualType IdxTy = E->getIdx()->getType();
3464  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3465  SignedIndices |= IdxSigned;
3466 
3467  if (SanOpts.has(SanitizerKind::ArrayBounds))
3468  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3469 
3470  // Extend or truncate the index type to 32 or 64-bits.
3471  if (Promote && Idx->getType() != IntPtrTy)
3472  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3473 
3474  return Idx;
3475  };
3476  IdxPre = nullptr;
3477 
3478  // If the base is a vector type, then we are forming a vector element lvalue
3479  // with this subscript.
3480  if (E->getBase()->getType()->isVectorType() &&
3481  !isa<ExtVectorElementExpr>(E->getBase())) {
3482  // Emit the vector as an lvalue to get its address.
3483  LValue LHS = EmitLValue(E->getBase());
3484  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3485  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3486  return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3487  LHS.getBaseInfo(), TBAAAccessInfo());
3488  }
3489 
3490  // All the other cases basically behave like simple offsetting.
3491 
3492  // Handle the extvector case we ignored above.
3493  if (isa<ExtVectorElementExpr>(E->getBase())) {
3494  LValue LV = EmitLValue(E->getBase());
3495  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3497 
3498  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3499  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3500  SignedIndices, E->getExprLoc());
3501  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3502  CGM.getTBAAInfoForSubobject(LV, EltType));
3503  }
3504 
3505  LValueBaseInfo EltBaseInfo;
3506  TBAAAccessInfo EltTBAAInfo;
3507  Address Addr = Address::invalid();
3508  if (const VariableArrayType *vla =
3509  getContext().getAsVariableArrayType(E->getType())) {
3510  // The base must be a pointer, which is not an aggregate. Emit
3511  // it. It needs to be emitted first in case it's what captures
3512  // the VLA bounds.
3513  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3514  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3515 
3516  // The element count here is the total number of non-VLA elements.
3517  llvm::Value *numElements = getVLASize(vla).NumElts;
3518 
3519  // Effectively, the multiply by the VLA size is part of the GEP.
3520  // GEP indexes are signed, and scaling an index isn't permitted to
3521  // signed-overflow, so we use the same semantics for our explicit
3522  // multiply. We suppress this if overflow is not undefined behavior.
3523  if (getLangOpts().isSignedOverflowDefined()) {
3524  Idx = Builder.CreateMul(Idx, numElements);
3525  } else {
3526  Idx = Builder.CreateNSWMul(Idx, numElements);
3527  }
3528 
3529  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3531  SignedIndices, E->getExprLoc());
3532 
3533  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3534  // Indexing over an interface, as in "NSString *P; P[4];"
3535 
3536  // Emit the base pointer.
3537  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3538  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3539 
3540  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3541  llvm::Value *InterfaceSizeVal =
3542  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3543 
3544  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3545 
3546  // We don't necessarily build correct LLVM struct types for ObjC
3547  // interfaces, so we can't rely on GEP to do this scaling
3548  // correctly, so we need to cast to i8*. FIXME: is this actually
3549  // true? A lot of other things in the fragile ABI would break...
3550  llvm::Type *OrigBaseTy = Addr.getType();
3551  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3552 
3553  // Do the GEP.
3554  CharUnits EltAlign =
3555  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3556  llvm::Value *EltPtr =
3557  emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3558  SignedIndices, E->getExprLoc());
3559  Addr = Address(EltPtr, EltAlign);
3560 
3561  // Cast back.
3562  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3563  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3564  // If this is A[i] where A is an array, the frontend will have decayed the
3565  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3566  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3567  // "gep x, i" here. Emit one "gep A, 0, i".
3568  assert(Array->getType()->isArrayType() &&
3569  "Array to pointer decay must have array source type!");
3570  LValue ArrayLV;
3571  // For simple multidimensional array indexing, set the 'accessed' flag for
3572  // better bounds-checking of the base expression.
3573  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3574  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3575  else
3576  ArrayLV = EmitLValue(Array);
3577  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3578 
3579  // Propagate the alignment from the array itself to the result.
3580  QualType arrayType = Array->getType();
3581  Addr = emitArraySubscriptGEP(
3582  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3583  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3584  E->getExprLoc(), &arrayType);
3585  EltBaseInfo = ArrayLV.getBaseInfo();
3586  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3587  } else {
3588  // The base must be a pointer; emit it with an estimate of its alignment.
3589  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3590  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3591  QualType ptrType = E->getBase()->getType();
3592  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3594  SignedIndices, E->getExprLoc(), &ptrType);
3595  }
3596 
3597  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3598 
3599  if (getLangOpts().ObjC &&
3600  getLangOpts().getGC() != LangOptions::NonGC) {
3602  setObjCGCLValueClass(getContext(), E, LV);
3603  }
3604  return LV;
3605 }
3606 
3608  LValueBaseInfo &BaseInfo,
3609  TBAAAccessInfo &TBAAInfo,
3610  QualType BaseTy, QualType ElTy,
3611  bool IsLowerBound) {
3612  LValue BaseLVal;
3613  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3614  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3615  if (BaseTy->isArrayType()) {
3616  Address Addr = BaseLVal.getAddress();
3617  BaseInfo = BaseLVal.getBaseInfo();
3618 
3619  // If the array type was an incomplete type, we need to make sure
3620  // the decay ends up being the right type.
3621  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3622  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3623 
3624  // Note that VLA pointers are always decayed, so we don't need to do
3625  // anything here.
3626  if (!BaseTy->isVariableArrayType()) {
3627  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3628  "Expected pointer to array");
3629  Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3630  }
3631 
3632  return CGF.Builder.CreateElementBitCast(Addr,
3633  CGF.ConvertTypeForMem(ElTy));
3634  }
3635  LValueBaseInfo TypeBaseInfo;
3636  TBAAAccessInfo TypeTBAAInfo;
3637  CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3638  &TypeTBAAInfo);
3639  BaseInfo.mergeForCast(TypeBaseInfo);
3640  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3641  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3642  }
3643  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3644 }
3645 
3647  bool IsLowerBound) {
3649  QualType ResultExprTy;
3650  if (auto *AT = getContext().getAsArrayType(BaseTy))
3651  ResultExprTy = AT->getElementType();
3652  else
3653  ResultExprTy = BaseTy->getPointeeType();
3654  llvm::Value *Idx = nullptr;
3655  if (IsLowerBound || E->getColonLoc().isInvalid()) {
3656  // Requesting lower bound or upper bound, but without provided length and
3657  // without ':' symbol for the default length -> length = 1.
3658  // Idx = LowerBound ?: 0;
3659  if (auto *LowerBound = E->getLowerBound()) {
3660  Idx = Builder.CreateIntCast(
3661  EmitScalarExpr(LowerBound), IntPtrTy,
3662  LowerBound->getType()->hasSignedIntegerRepresentation());
3663  } else
3664  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3665  } else {
3666  // Try to emit length or lower bound as constant. If this is possible, 1
3667  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3668  // IR (LB + Len) - 1.
3669  auto &C = CGM.getContext();
3670  auto *Length = E->getLength();
3671  llvm::APSInt ConstLength;
3672  if (Length) {
3673  // Idx = LowerBound + Length - 1;
3674  if (Length->isIntegerConstantExpr(ConstLength, C)) {
3675  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3676  Length = nullptr;
3677  }
3678  auto *LowerBound = E->getLowerBound();
3679  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3680  if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3681  ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3682  LowerBound = nullptr;
3683  }
3684  if (!Length)
3685  --ConstLength;
3686  else if (!LowerBound)
3687  --ConstLowerBound;
3688 
3689  if (Length || LowerBound) {
3690  auto *LowerBoundVal =
3691  LowerBound
3692  ? Builder.CreateIntCast(
3693  EmitScalarExpr(LowerBound), IntPtrTy,
3694  LowerBound->getType()->hasSignedIntegerRepresentation())
3695  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3696  auto *LengthVal =
3697  Length
3698  ? Builder.CreateIntCast(
3699  EmitScalarExpr(Length), IntPtrTy,
3700  Length->getType()->hasSignedIntegerRepresentation())
3701  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3702  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3703  /*HasNUW=*/false,
3704  !getLangOpts().isSignedOverflowDefined());
3705  if (Length && LowerBound) {
3706  Idx = Builder.CreateSub(
3707  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3708  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3709  }
3710  } else
3711  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3712  } else {
3713  // Idx = ArraySize - 1;
3714  QualType ArrayTy = BaseTy->isPointerType()
3715  ? E->getBase()->IgnoreParenImpCasts()->getType()
3716  : BaseTy;
3717  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3718  Length = VAT->getSizeExpr();
3719  if (Length->isIntegerConstantExpr(ConstLength, C))
3720  Length = nullptr;
3721  } else {
3722  auto *CAT = C.getAsConstantArrayType(ArrayTy);
3723  ConstLength = CAT->getSize();
3724  }
3725  if (Length) {
3726  auto *LengthVal = Builder.CreateIntCast(
3727  EmitScalarExpr(Length), IntPtrTy,
3728  Length->getType()->hasSignedIntegerRepresentation());
3729  Idx = Builder.CreateSub(
3730  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3731  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3732  } else {
3733  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3734  --ConstLength;
3735  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3736  }
3737  }
3738  }
3739  assert(Idx);
3740 
3741  Address EltPtr = Address::invalid();
3742  LValueBaseInfo BaseInfo;
3743  TBAAAccessInfo TBAAInfo;
3744  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3745  // The base must be a pointer, which is not an aggregate. Emit
3746  // it. It needs to be emitted first in case it's what captures
3747  // the VLA bounds.
3748  Address Base =
3749  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3750  BaseTy, VLA->getElementType(), IsLowerBound);
3751  // The element count here is the total number of non-VLA elements.
3752  llvm::Value *NumElements = getVLASize(VLA).NumElts;
3753 
3754  // Effectively, the multiply by the VLA size is part of the GEP.
3755  // GEP indexes are signed, and scaling an index isn't permitted to
3756  // signed-overflow, so we use the same semantics for our explicit
3757  // multiply. We suppress this if overflow is not undefined behavior.
3758  if (getLangOpts().isSignedOverflowDefined())
3759  Idx = Builder.CreateMul(Idx, NumElements);
3760  else
3761  Idx = Builder.CreateNSWMul(Idx, NumElements);
3762  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3764  /*signedIndices=*/false, E->getExprLoc());
3765  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3766  // If this is A[i] where A is an array, the frontend will have decayed the
3767  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3768  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3769  // "gep x, i" here. Emit one "gep A, 0, i".
3770  assert(Array->getType()->isArrayType() &&
3771  "Array to pointer decay must have array source type!");
3772  LValue ArrayLV;
3773  // For simple multidimensional array indexing, set the 'accessed' flag for
3774  // better bounds-checking of the base expression.
3775  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3776  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3777  else
3778  ArrayLV = EmitLValue(Array);
3779 
3780  // Propagate the alignment from the array itself to the result.
3781  EltPtr = emitArraySubscriptGEP(
3782  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3783  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3784  /*signedIndices=*/false, E->getExprLoc());
3785  BaseInfo = ArrayLV.getBaseInfo();
3786  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3787  } else {
3788  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3789  TBAAInfo, BaseTy, ResultExprTy,
3790  IsLowerBound);
3791  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3792  !getLangOpts().isSignedOverflowDefined(),
3793  /*signedIndices=*/false, E->getExprLoc());
3794  }
3795 
3796  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3797 }
3798 
3801  // Emit the base vector as an l-value.
3802  LValue Base;
3803 
3804  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3805  if (E->isArrow()) {
3806  // If it is a pointer to a vector, emit the address and form an lvalue with
3807  // it.
3808  LValueBaseInfo BaseInfo;
3809  TBAAAccessInfo TBAAInfo;
3810  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3811  const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3812  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3813  Base.getQuals().removeObjCGCAttr();
3814  } else if (E->getBase()->isGLValue()) {
3815  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3816  // emit the base as an lvalue.
3817  assert(E->getBase()->getType()->isVectorType());
3818  Base = EmitLValue(E->getBase());
3819  } else {
3820  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3821  assert(E->getBase()->getType()->isVectorType() &&
3822  "Result must be a vector");
3823  llvm::Value *Vec = EmitScalarExpr(E->getBase());
3824 
3825  // Store the vector to memory (because LValue wants an address).
3826  Address VecMem = CreateMemTemp(E->getBase()->getType());
3827  Builder.CreateStore(Vec, VecMem);
3828  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3830  }
3831 
3832  QualType type =
3834 
3835  // Encode the element access list into a vector of unsigned indices.
3836  SmallVector<uint32_t, 4> Indices;
3837  E->getEncodedElementAccess(Indices);
3838 
3839  if (Base.isSimple()) {
3840  llvm::Constant *CV =
3841  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3842  return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3843  Base.getBaseInfo(), TBAAAccessInfo());
3844  }
3845  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3846 
3847  llvm::Constant *BaseElts = Base.getExtVectorElts();
3849 
3850  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3851  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3852  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3854  Base.getBaseInfo(), TBAAAccessInfo());
3855 }
3856 
3858  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3859  EmitIgnoredExpr(E->getBase());
3860  return EmitDeclRefLValue(DRE);
3861  }
3862 
3863  Expr *BaseExpr = E->getBase();
3864  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3865  LValue BaseLV;
3866  if (E->isArrow()) {
3867  LValueBaseInfo BaseInfo;
3868  TBAAAccessInfo TBAAInfo;
3869  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3870  QualType PtrTy = BaseExpr->getType()->getPointeeType();
3871  SanitizerSet SkippedChecks;
3872  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3873  if (IsBaseCXXThis)
3874  SkippedChecks.set(SanitizerKind::Alignment, true);
3875  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3876  SkippedChecks.set(SanitizerKind::Null, true);
3877  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3878  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3879  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3880  } else
3881  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3882 
3883  NamedDecl *ND = E->getMemberDecl();
3884  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3885  LValue LV = EmitLValueForField(BaseLV, Field);
3886  setObjCGCLValueClass(getContext(), E, LV);
3887  return LV;
3888  }
3889 
3890  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3891  return EmitFunctionDeclLValue(*this, E, FD);
3892 
3893  llvm_unreachable("Unhandled member declaration!");
3894 }
3895 
3896 /// Given that we are currently emitting a lambda, emit an l-value for
3897 /// one of its members.
3899  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3900  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3901  QualType LambdaTagType =
3902  getContext().getTagDeclType(Field->getParent());
3903  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3904  return EmitLValueForField(LambdaLV, Field);
3905 }
3906 
3907 /// Get the field index in the debug info. The debug info structure/union
3908 /// will ignore the unnamed bitfields.
3910  unsigned FieldIndex) {
3911  unsigned I = 0, Skipped = 0;
3912 
3913  for (auto F : Rec->getDefinition()->fields()) {
3914  if (I == FieldIndex)
3915  break;
3916  if (F->isUnnamedBitfield())
3917  Skipped++;
3918  I++;
3919  }
3920 
3921  return FieldIndex - Skipped;
3922 }
3923 
3924 /// Get the address of a zero-sized field within a record. The resulting
3925 /// address doesn't necessarily have the right type.
3927  const FieldDecl *Field) {
3929  CGF.getContext().getFieldOffset(Field));
3930  if (Offset.isZero())
3931  return Base;
3932  Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty);
3933  return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
3934 }
3935 
3936 /// Drill down to the storage of a field without walking into
3937 /// reference types.
3938 ///
3939 /// The resulting address doesn't necessarily have the right type.
3941  const FieldDecl *field) {
3942  if (field->isZeroSize(CGF.getContext()))
3943  return emitAddrOfZeroSizeField(CGF, base, field);
3944 
3945  const RecordDecl *rec = field->getParent();
3946 
3947  unsigned idx =
3948  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3949 
3950  return CGF.Builder.CreateStructGEP(base, idx, field->getName());
3951 }
3952 
3954  const FieldDecl *field) {
3955  const RecordDecl *rec = field->getParent();
3956  llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateRecordType(
3957  CGF.getContext().getRecordType(rec), rec->getLocation());
3958 
3959  unsigned idx =
3960  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3961 
3963  base, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
3964 }
3965 
3966 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3967  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3968  if (!RD)
3969  return false;
3970 
3971  if (RD->isDynamicClass())
3972  return true;
3973 
3974  for (const auto &Base : RD->bases())
3975  if (hasAnyVptr(Base.getType(), Context))
3976  return true;
3977 
3978  for (const FieldDecl *Field : RD->fields())
3979  if (hasAnyVptr(Field->getType(), Context))
3980  return true;
3981 
3982  return false;
3983 }
3984 
3986  const FieldDecl *field) {
3987  LValueBaseInfo BaseInfo = base.getBaseInfo();
3988 
3989  if (field->isBitField()) {
3990  const CGRecordLayout &RL =
3992  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3993  Address Addr = base.getAddress();
3994  unsigned Idx = RL.getLLVMFieldNo(field);
3995  if (!IsInPreservedAIRegion) {
3996  if (Idx != 0)
3997  // For structs, we GEP to the field that the record layout suggests.
3998  Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
3999  } else {
4000  const RecordDecl *rec = field->getParent();
4001  llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4002  getContext().getRecordType(rec), rec->getLocation());
4003  Addr = Builder.CreatePreserveStructAccessIndex(Addr, Idx,
4004  getDebugInfoFIndex(rec, field->getFieldIndex()),
4005  DbgInfo);
4006  }
4007 
4008  // Get the access type.
4009  llvm::Type *FieldIntTy =
4010  llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
4011  if (Addr.getElementType() != FieldIntTy)
4012  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
4013 
4014  QualType fieldType =
4015  field->getType().withCVRQualifiers(base.getVRQualifiers());
4016  // TODO: Support TBAA for bit fields.
4017  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4018  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4019  TBAAAccessInfo());
4020  }
4021 
4022  // Fields of may-alias structures are may-alias themselves.
4023  // FIXME: this should get propagated down through anonymous structs
4024  // and unions.
4025  QualType FieldType = field->getType();
4026  const RecordDecl *rec = field->getParent();
4027  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4028  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4029  TBAAAccessInfo FieldTBAAInfo;
4030  if (base.getTBAAInfo().isMayAlias() ||
4031  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4032  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4033  } else if (rec->isUnion()) {
4034  // TODO: Support TBAA for unions.
4035  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4036  } else {
4037  // If no base type been assigned for the base access, then try to generate
4038  // one for this base lvalue.
4039  FieldTBAAInfo = base.getTBAAInfo();
4040  if (!FieldTBAAInfo.BaseType) {
4041  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4042  assert(!FieldTBAAInfo.Offset &&
4043  "Nonzero offset for an access with no base type!");
4044  }
4045 
4046  // Adjust offset to be relative to the base type.
4047  const ASTRecordLayout &Layout =
4049  unsigned CharWidth = getContext().getCharWidth();
4050  if (FieldTBAAInfo.BaseType)
4051  FieldTBAAInfo.Offset +=
4052  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4053 
4054  // Update the final access type and size.
4055  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4056  FieldTBAAInfo.Size =
4057  getContext().getTypeSizeInChars(FieldType).getQuantity();
4058  }
4059 
4060  Address addr = base.getAddress();
4061  if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4062  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4063  ClassDef->isDynamicClass()) {
4064  // Getting to any field of dynamic object requires stripping dynamic
4065  // information provided by invariant.group. This is because accessing
4066  // fields may leak the real address of dynamic object, which could result
4067  // in miscompilation when leaked pointer would be compared.
4068  auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4069  addr = Address(stripped, addr.getAlignment());
4070  }
4071  }
4072 
4073  unsigned RecordCVR = base.getVRQualifiers();
4074  if (rec->isUnion()) {
4075  // For unions, there is no pointer adjustment.
4076  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4077  hasAnyVptr(FieldType, getContext()))
4078  // Because unions can easily skip invariant.barriers, we need to add
4079  // a barrier every time CXXRecord field with vptr is referenced.
4080  addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
4081  addr.getAlignment());
4082 
4083  if (IsInPreservedAIRegion) {
4084  // Remember the original union field index
4085  llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4086  getContext().getRecordType(rec), rec->getLocation());
4087  addr = Address(
4088  Builder.CreatePreserveUnionAccessIndex(
4089  addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4090  addr.getAlignment());
4091  }
4092 
4093  if (FieldType->isReferenceType())
4095  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4096  } else {
4097  if (!IsInPreservedAIRegion)
4098  // For structs, we GEP to the field that the record layout suggests.
4099  addr = emitAddrOfFieldStorage(*this, addr, field);
4100  else
4101  // Remember the original struct field index
4102  addr = emitPreserveStructAccess(*this, addr, field);
4103  }
4104 
4105  // If this is a reference field, load the reference right now.
4106  if (FieldType->isReferenceType()) {
4107  LValue RefLVal =
4108  MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4109  if (RecordCVR & Qualifiers::Volatile)
4110  RefLVal.getQuals().addVolatile();
4111  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4112 
4113  // Qualifiers on the struct don't apply to the referencee.
4114  RecordCVR = 0;
4115  FieldType = FieldType->getPointeeType();
4116  }
4117 
4118  // Make sure that the address is pointing to the right type. This is critical
4119  // for both unions and structs. A union needs a bitcast, a struct element
4120  // will need a bitcast if the LLVM type laid out doesn't match the desired
4121  // type.
4123  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4124 
4125  if (field->hasAttr<AnnotateAttr>())
4126  addr = EmitFieldAnnotations(field, addr);
4127 
4128  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4129  LV.getQuals().addCVRQualifiers(RecordCVR);
4130 
4131  // __weak attribute on a field is ignored.
4132  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4133  LV.getQuals().removeObjCGCAttr();
4134 
4135  return LV;
4136 }
4137 
4138 LValue
4140  const FieldDecl *Field) {
4141  QualType FieldType = Field->getType();
4142 
4143  if (!FieldType->isReferenceType())
4144  return EmitLValueForField(Base, Field);
4145 
4146  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
4147 
4148  // Make sure that the address is pointing to the right type.
4149  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4150  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4151 
4152  // TODO: Generate TBAA information that describes this access as a structure
4153  // member access and not just an access to an object of the field's type. This
4154  // should be similar to what we do in EmitLValueForField().
4155  LValueBaseInfo BaseInfo = Base.getBaseInfo();
4156  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4157  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4158  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4159  CGM.getTBAAInfoForSubobject(Base, FieldType));
4160 }
4161 
4163  if (E->isFileScope()) {
4165  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4166  }
4167  if (E->getType()->isVariablyModifiedType())
4168  // make sure to emit the VLA size.
4170 
4171  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4172  const Expr *InitExpr = E->getInitializer();
4173  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4174 
4175  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4176  /*Init*/ true);
4177 
4178  return Result;
4179 }
4180 
4182  if (!E->isGLValue())
4183  // Initializing an aggregate temporary in C++11: T{...}.
4184  return EmitAggExprToLValue(E);
4185 
4186  // An lvalue initializer list must be initializing a reference.
4187  assert(E->isTransparent() && "non-transparent glvalue init list");
4188  return EmitLValue(E->getInit(0));
4189 }
4190 
4191 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4192 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4193 /// LValue is returned and the current block has been terminated.
4195  const Expr *Operand) {
4196  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4197  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4198  return None;
4199  }
4200 
4201  return CGF.EmitLValue(Operand);
4202 }
4203 
4206  if (!expr->isGLValue()) {
4207  // ?: here should be an aggregate.
4208  assert(hasAggregateEvaluationKind(expr->getType()) &&
4209  "Unexpected conditional operator!");
4210  return EmitAggExprToLValue(expr);
4211  }
4212 
4213  OpaqueValueMapping binding(*this, expr);
4214 
4215  const Expr *condExpr = expr->getCond();
4216  bool CondExprBool;
4217  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4218  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4219  if (!CondExprBool) std::swap(live, dead);
4220 
4221  if (!ContainsLabel(dead)) {
4222  // If the true case is live, we need to track its region.
4223  if (CondExprBool)
4225  return EmitLValue(live);
4226  }
4227  }
4228 
4229  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4230  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4231  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4232 
4233  ConditionalEvaluation eval(*this);
4234  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4235 
4236  // Any temporaries created here are conditional.
4237  EmitBlock(lhsBlock);
4239  eval.begin(*this);
4240  Optional<LValue> lhs =
4241  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4242  eval.end(*this);
4243 
4244  if (lhs && !lhs->isSimple())
4245  return EmitUnsupportedLValue(expr, "conditional operator");
4246 
4247  lhsBlock = Builder.GetInsertBlock();
4248  if (lhs)
4249  Builder.CreateBr(contBlock);
4250 
4251  // Any temporaries created here are conditional.
4252  EmitBlock(rhsBlock);
4253  eval.begin(*this);
4254  Optional<LValue> rhs =
4255  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4256  eval.end(*this);
4257  if (rhs && !rhs->isSimple())
4258  return EmitUnsupportedLValue(expr, "conditional operator");
4259  rhsBlock = Builder.GetInsertBlock();
4260 
4261  EmitBlock(contBlock);
4262 
4263  if (lhs && rhs) {
4264  llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4265  2, "cond-lvalue");
4266  phi->addIncoming(lhs->getPointer(), lhsBlock);
4267  phi->addIncoming(rhs->getPointer(), rhsBlock);
4268  Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4269  AlignmentSource alignSource =
4270  std::max(lhs->getBaseInfo().getAlignmentSource(),
4271  rhs->getBaseInfo().getAlignmentSource());
4273  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4274  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4275  TBAAInfo);
4276  } else {
4277  assert((lhs || rhs) &&
4278  "both operands of glvalue conditional are throw-expressions?");
4279  return lhs ? *lhs : *rhs;
4280  }
4281 }
4282 
4283 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4284 /// type. If the cast is to a reference, we can have the usual lvalue result,
4285 /// otherwise if a cast is needed by the code generator in an lvalue context,
4286 /// then it must mean that we need the address of an aggregate in order to
4287 /// access one of its members. This can happen for all the reasons that casts
4288 /// are permitted with aggregate result, including noop aggregate casts, and
4289 /// cast from scalar to union.
4291  switch (E->getCastKind()) {
4292  case CK_ToVoid:
4293  case CK_BitCast:
4294  case CK_LValueToRValueBitCast:
4295  case CK_ArrayToPointerDecay:
4296  case CK_FunctionToPointerDecay:
4297  case CK_NullToMemberPointer:
4298  case CK_NullToPointer:
4299  case CK_IntegralToPointer:
4300  case CK_PointerToIntegral:
4301  case CK_PointerToBoolean:
4302  case CK_VectorSplat:
4303  case CK_IntegralCast:
4304  case CK_BooleanToSignedIntegral:
4305  case CK_IntegralToBoolean:
4306  case CK_IntegralToFloating:
4307  case CK_FloatingToIntegral:
4308  case CK_FloatingToBoolean:
4309  case CK_FloatingCast:
4310  case CK_FloatingRealToComplex:
4311  case CK_FloatingComplexToReal:
4312  case CK_FloatingComplexToBoolean:
4313  case CK_FloatingComplexCast:
4314  case CK_FloatingComplexToIntegralComplex:
4315  case CK_IntegralRealToComplex:
4316  case CK_IntegralComplexToReal:
4317  case CK_IntegralComplexToBoolean:
4318  case CK_IntegralComplexCast:
4319  case CK_IntegralComplexToFloatingComplex:
4320  case CK_DerivedToBaseMemberPointer:
4321  case CK_BaseToDerivedMemberPointer:
4322  case CK_MemberPointerToBoolean:
4323  case CK_ReinterpretMemberPointer:
4324  case CK_AnyPointerToBlockPointerCast:
4325  case CK_ARCProduceObject:
4326  case CK_ARCConsumeObject:
4327  case CK_ARCReclaimReturnedObject:
4328  case CK_ARCExtendBlockObject:
4329  case CK_CopyAndAutoreleaseBlockObject:
4330  case CK_IntToOCLSampler:
4331  case CK_FixedPointCast:
4332  case CK_FixedPointToBoolean:
4333  case CK_FixedPointToIntegral:
4334  case CK_IntegralToFixedPoint:
4335  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4336 
4337  case CK_Dependent:
4338  llvm_unreachable("dependent cast kind in IR gen!");
4339 
4340  case CK_BuiltinFnToFnPtr:
4341  llvm_unreachable("builtin functions are handled elsewhere");
4342 
4343  // These are never l-values; just use the aggregate emission code.
4344  case CK_NonAtomicToAtomic:
4345  case CK_AtomicToNonAtomic:
4346  return EmitAggExprToLValue(E);
4347 
4348  case CK_Dynamic: {
4349  LValue LV = EmitLValue(E->getSubExpr());
4350  Address V = LV.getAddress();
4351  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4352  return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4353  }
4354 
4355  case CK_ConstructorConversion:
4356  case CK_UserDefinedConversion:
4357  case CK_CPointerToObjCPointerCast:
4358  case CK_BlockPointerToObjCPointerCast:
4359  case CK_NoOp:
4360  case CK_LValueToRValue:
4361  return EmitLValue(E->getSubExpr());
4362 
4363  case CK_UncheckedDerivedToBase:
4364  case CK_DerivedToBase: {
4365  const RecordType *DerivedClassTy =
4366  E->getSubExpr()->getType()->getAs<RecordType>();
4367  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4368 
4369  LValue LV = EmitLValue(E->getSubExpr());
4370  Address This = LV.getAddress();
4371 
4372  // Perform the derived-to-base conversion
4374  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4375  /*NullCheckValue=*/false, E->getExprLoc());
4376 
4377  // TODO: Support accesses to members of base classes in TBAA. For now, we
4378  // conservatively pretend that the complete object is of the base class
4379  // type.
4380  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4381  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4382  }
4383  case CK_ToUnion:
4384  return EmitAggExprToLValue(E);
4385  case CK_BaseToDerived: {
4386  const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4387  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4388 
4389  LValue LV = EmitLValue(E->getSubExpr());
4390 
4391  // Perform the base-to-derived conversion
4392  Address Derived =
4393  GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4394  E->path_begin(), E->path_end(),
4395  /*NullCheckValue=*/false);
4396 
4397  // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4398  // performed and the object is not of the derived type.
4401  Derived.getPointer(), E->getType());
4402 
4403  if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4404  EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4405  /*MayBeNull=*/false, CFITCK_DerivedCast,
4406  E->getBeginLoc());
4407 
4408  return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4409  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4410  }
4411  case CK_LValueBitCast: {
4412  // This must be a reinterpret_cast (or c-style equivalent).
4413  const auto *CE = cast<ExplicitCastExpr>(E);
4414 
4415  CGM.EmitExplicitCastExprType(CE, this);
4416  LValue LV = EmitLValue(E->getSubExpr());
4418  ConvertType(CE->getTypeAsWritten()));
4419 
4420  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4421  EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4422  /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4423  E->getBeginLoc());
4424 
4425  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4426  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4427  }
4428  case CK_AddressSpaceConversion: {
4429  LValue LV = EmitLValue(E->getSubExpr());
4430  QualType DestTy = getContext().getPointerType(E->getType());
4432  *this, LV.getPointer(), E->getSubExpr()->getType().getAddressSpace(),
4433  E->getType().getAddressSpace(), ConvertType(DestTy));
4434  return MakeAddrLValue(Address(V, LV.getAddress().getAlignment()),
4435  E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4436  }
4437  case CK_ObjCObjectLValueCast: {
4438  LValue LV = EmitLValue(E->getSubExpr());
4440  ConvertType(E->getType()));
4441  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4442  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4443  }
4444  case CK_ZeroToOCLOpaqueType:
4445  llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4446  }
4447 
4448  llvm_unreachable("Unhandled lvalue cast kind?");
4449 }
4450 
4454 }
4455 
4456 LValue
4459 
4460  llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4461  it = OpaqueLValues.find(e);
4462 
4463  if (it != OpaqueLValues.end())
4464  return it->second;
4465 
4466  assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4467  return EmitLValue(e->getSourceExpr());
4468 }
4469 
4470 RValue
4473 
4474  llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4475  it = OpaqueRValues.find(e);
4476 
4477  if (it != OpaqueRValues.end())
4478  return it->second;
4479 
4480  assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4481  return EmitAnyExpr(e->getSourceExpr());
4482 }
4483 
4485  const FieldDecl *FD,
4486  SourceLocation Loc) {
4487  QualType FT = FD->getType();
4488  LValue FieldLV = EmitLValueForField(LV, FD);
4489  switch (getEvaluationKind(FT)) {
4490  case TEK_Complex:
4491  return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4492  case TEK_Aggregate:
4493  return FieldLV.asAggregateRValue();
4494  case TEK_Scalar:
4495  // This routine is used to load fields one-by-one to perform a copy, so
4496  // don't load reference fields.
4497  if (FD->getType()->isReferenceType())
4498  return RValue::get(FieldLV.getPointer());
4499  return EmitLoadOfLValue(FieldLV, Loc);
4500  }
4501  llvm_unreachable("bad evaluation kind");
4502 }
4503 
4504 //===--------------------------------------------------------------------===//
4505 // Expression Emission
4506 //===--------------------------------------------------------------------===//
4507 
4510  // Builtins never have block type.
4511  if (E->getCallee()->getType()->isBlockPointerType())
4512  return EmitBlockCallExpr(E, ReturnValue);
4513 
4514  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4515  return EmitCXXMemberCallExpr(CE, ReturnValue);
4516 
4517  if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4518  return EmitCUDAKernelCallExpr(CE, ReturnValue);
4519 
4520  if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4521  if (const CXXMethodDecl *MD =
4522  dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4523  return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4524 
4525  CGCallee callee = EmitCallee(E->getCallee());
4526 
4527  if (callee.isBuiltin()) {
4528  return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4529  E, ReturnValue);
4530  }
4531 
4532  if (callee.isPseudoDestructor()) {
4534  }
4535 
4536  return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4537 }
4538 
4539 /// Emit a CallExpr without considering whether it might be a subclass.
4542  CGCallee Callee = EmitCallee(E->getCallee());
4543  return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4544 }
4545 
4547  if (auto builtinID = FD->getBuiltinID()) {
4548  return CGCallee::forBuiltin(builtinID, FD);
4549  }
4550 
4551  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4552  return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
4553 }
4554 
4556  E = E->IgnoreParens();
4557 
4558  // Look through function-to-pointer decay.
4559  if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4560  if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4561  ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4562  return EmitCallee(ICE->getSubExpr());
4563  }
4564 
4565  // Resolve direct calls.
4566  } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4567  if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4568  return EmitDirectCallee(*this, FD);
4569  }
4570  } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4571  if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4572  EmitIgnoredExpr(ME->getBase());
4573  return EmitDirectCallee(*this, FD);
4574  }
4575 
4576  // Look through template substitutions.
4577  } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4578  return EmitCallee(NTTP->getReplacement());
4579 
4580  // Treat pseudo-destructor calls differently.
4581  } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4582  return CGCallee::forPseudoDestructor(PDE);
4583  }
4584 
4585  // Otherwise, we have an indirect reference.
4586  llvm::Value *calleePtr;
4588  if (auto ptrType = E->getType()->getAs<PointerType>()) {
4589  calleePtr = EmitScalarExpr(E);
4590  functionType = ptrType->getPointeeType();
4591  } else {
4592  functionType = E->getType();
4593  calleePtr = EmitLValue(E).getPointer();
4594  }
4595  assert(functionType->isFunctionType());
4596 
4597  GlobalDecl GD;
4598  if (const auto *VD =
4599  dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4600  GD = GlobalDecl(VD);
4601 
4602  CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4603  CGCallee callee(calleeInfo, calleePtr);
4604  return callee;
4605 }
4606 
4608  // Comma expressions just emit their LHS then their RHS as an l-value.
4609  if (E->getOpcode() == BO_Comma) {
4610  EmitIgnoredExpr(E->getLHS());
4612  return EmitLValue(E->getRHS());
4613  }
4614 
4615  if (E->getOpcode() == BO_PtrMemD ||
4616  E->getOpcode() == BO_PtrMemI)
4618 
4619  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4620 
4621  // Note that in all of these cases, __block variables need the RHS
4622  // evaluated first just in case the variable gets moved by the RHS.
4623 
4624  switch (getEvaluationKind(E->getType())) {
4625  case TEK_Scalar: {
4626  switch (E->getLHS()->getType().getObjCLifetime()) {
4628  return EmitARCStoreStrong(E, /*ignored*/ false).first;
4629 
4631  return EmitARCStoreAutoreleasing(E).first;
4632 
4633  // No reason to do any of these differently.
4634  case Qualifiers::OCL_None:
4636  case Qualifiers::OCL_Weak:
4637  break;
4638  }
4639 
4640  RValue RV = EmitAnyExpr(E->getRHS());
4642  if (RV.isScalar())
4644  EmitStoreThroughLValue(RV, LV);
4645  return LV;
4646  }
4647 
4648  case TEK_Complex:
4649  return EmitComplexAssignmentLValue(E);
4650 
4651  case TEK_Aggregate:
4652  return EmitAggExprToLValue(E);
4653  }
4654  llvm_unreachable("bad evaluation kind");
4655 }
4656 
4658  RValue RV = EmitCallExpr(E);
4659 
4660  if (!RV.isScalar())
4661  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4663 
4664  assert(E->getCallReturnType(getContext())->isReferenceType() &&
4665  "Can't have a scalar return unless the return type is a "
4666  "reference type!");
4667 
4669 }
4670 
4672  // FIXME: This shouldn't require another copy.
4673  return EmitAggExprToLValue(E);
4674 }
4675 
4678  && "binding l-value to type which needs a temporary");
4679  AggValueSlot Slot = CreateAggTemp(E->getType());
4680  EmitCXXConstructExpr(E, Slot);
4681  return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4682 }
4683 
4684 LValue
4687 }
4688 
4691  ConvertType(E->getType()));
4692 }
4693 
4695  return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4697 }
4698 
4699 LValue
4701  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4702  Slot.setExternallyDestructed();
4703  EmitAggExpr(E->getSubExpr(), Slot);
4704  EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4706 }
4707 
4709  RValue RV = EmitObjCMessageExpr(E);
4710 
4711  if (!RV.isScalar())
4712  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4714 
4715  assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4716  "Can't have a scalar return unless the return type is a "
4717  "reference type!");
4718 
4720 }
4721 
4723  Address V =
4725  return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4726 }
4727 
4729  const ObjCIvarDecl *Ivar) {
4730  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4731 }
4732 
4734  llvm::Value *BaseValue,
4735  const ObjCIvarDecl *Ivar,
4736  unsigned CVRQualifiers) {
4737  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4738  Ivar, CVRQualifiers);
4739 }
4740 
4742  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4743  llvm::Value *BaseValue = nullptr;
4744  const Expr *BaseExpr = E->getBase();
4745  Qualifiers BaseQuals;
4746  QualType ObjectTy;
4747  if (E->isArrow()) {
4748  BaseValue = EmitScalarExpr(BaseExpr);
4749  ObjectTy = BaseExpr->getType()->getPointeeType();
4750  BaseQuals = ObjectTy.getQualifiers();
4751  } else {
4752  LValue BaseLV = EmitLValue(BaseExpr);
4753  BaseValue = BaseLV.getPointer();
4754  ObjectTy = BaseExpr->getType();
4755  BaseQuals = ObjectTy.getQualifiers();
4756  }
4757 
4758  LValue LV =
4759  EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4760  BaseQuals.getCVRQualifiers());
4761  setObjCGCLValueClass(getContext(), E, LV);
4762  return LV;
4763 }
4764 
4766  // Can only get l-value for message expression returning aggregate type
4767  RValue RV = EmitAnyExprToTemp(E);
4768  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4770 }
4771 
4772 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4774  llvm::Value *Chain) {
4775  // Get the actual function type. The callee type will always be a pointer to
4776  // function type or a block pointer type.