clang  10.0.0svn
CGExpr.cpp
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1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit Expr nodes as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CGCXXABI.h"
14 #include "CGCall.h"
15 #include "CGCleanup.h"
16 #include "CGDebugInfo.h"
17 #include "CGObjCRuntime.h"
18 #include "CGOpenMPRuntime.h"
19 #include "CGRecordLayout.h"
20 #include "CodeGenFunction.h"
21 #include "CodeGenModule.h"
22 #include "ConstantEmitter.h"
23 #include "TargetInfo.h"
24 #include "clang/AST/ASTContext.h"
25 #include "clang/AST/Attr.h"
26 #include "clang/AST/DeclObjC.h"
27 #include "clang/AST/NSAPI.h"
28 #include "clang/Basic/Builtins.h"
30 #include "llvm/ADT/Hashing.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/Intrinsics.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/MDBuilder.h"
36 #include "llvm/Support/ConvertUTF.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Transforms/Utils/SanitizerStats.h"
40 
41 #include <string>
42 
43 using namespace clang;
44 using namespace CodeGen;
45 
46 //===--------------------------------------------------------------------===//
47 // Miscellaneous Helper Methods
48 //===--------------------------------------------------------------------===//
49 
51  unsigned addressSpace =
52  cast<llvm::PointerType>(value->getType())->getAddressSpace();
53 
54  llvm::PointerType *destType = Int8PtrTy;
55  if (addressSpace)
56  destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
57 
58  if (value->getType() == destType) return value;
59  return Builder.CreateBitCast(value, destType);
60 }
61 
62 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
63 /// block.
65  CharUnits Align,
66  const Twine &Name,
67  llvm::Value *ArraySize) {
68  auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
69  Alloca->setAlignment(Align.getQuantity());
70  return Address(Alloca, Align);
71 }
72 
73 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
74 /// block. The alloca is casted to default address space if necessary.
76  const Twine &Name,
77  llvm::Value *ArraySize,
78  Address *AllocaAddr) {
79  auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
80  if (AllocaAddr)
81  *AllocaAddr = Alloca;
82  llvm::Value *V = Alloca.getPointer();
83  // Alloca always returns a pointer in alloca address space, which may
84  // be different from the type defined by the language. For example,
85  // in C++ the auto variables are in the default address space. Therefore
86  // cast alloca to the default address space when necessary.
88  auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
89  llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
90  // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
91  // otherwise alloca is inserted at the current insertion point of the
92  // builder.
93  if (!ArraySize)
94  Builder.SetInsertPoint(AllocaInsertPt);
97  Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
98  }
99 
100  return Address(V, Align);
101 }
102 
103 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
104 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
105 /// insertion point of the builder.
107  const Twine &Name,
108  llvm::Value *ArraySize) {
109  if (ArraySize)
110  return Builder.CreateAlloca(Ty, ArraySize, Name);
111  return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
112  ArraySize, Name, AllocaInsertPt);
113 }
114 
115 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
116 /// default alignment of the corresponding LLVM type, which is *not*
117 /// guaranteed to be related in any way to the expected alignment of
118 /// an AST type that might have been lowered to Ty.
120  const Twine &Name) {
121  CharUnits Align =
122  CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
123  return CreateTempAlloca(Ty, Align, Name);
124 }
125 
127  assert(isa<llvm::AllocaInst>(Var.getPointer()));
128  auto *Store = new llvm::StoreInst(Init, Var.getPointer());
129  Store->setAlignment(Var.getAlignment().getQuantity());
130  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
131  Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
132 }
133 
136  return CreateTempAlloca(ConvertType(Ty), Align, Name);
137 }
138 
140  Address *Alloca) {
141  // FIXME: Should we prefer the preferred type alignment here?
142  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
143 }
144 
146  const Twine &Name, Address *Alloca) {
147  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
148  /*ArraySize=*/nullptr, Alloca);
149 }
150 
152  const Twine &Name) {
153  return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
154 }
155 
157  const Twine &Name) {
158  return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
159  Name);
160 }
161 
162 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
163 /// expression and compare the result against zero, returning an Int1Ty value.
165  PGO.setCurrentStmt(E);
166  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
167  llvm::Value *MemPtr = EmitScalarExpr(E);
168  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
169  }
170 
171  QualType BoolTy = getContext().BoolTy;
172  SourceLocation Loc = E->getExprLoc();
173  if (!E->getType()->isAnyComplexType())
174  return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
175 
176  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
177  Loc);
178 }
179 
180 /// EmitIgnoredExpr - Emit code to compute the specified expression,
181 /// ignoring the result.
183  if (E->isRValue())
184  return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
185 
186  // Just emit it as an l-value and drop the result.
187  EmitLValue(E);
188 }
189 
190 /// EmitAnyExpr - Emit code to compute the specified expression which
191 /// can have any type. The result is returned as an RValue struct.
192 /// If this is an aggregate expression, AggSlot indicates where the
193 /// result should be returned.
195  AggValueSlot aggSlot,
196  bool ignoreResult) {
197  switch (getEvaluationKind(E->getType())) {
198  case TEK_Scalar:
199  return RValue::get(EmitScalarExpr(E, ignoreResult));
200  case TEK_Complex:
201  return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
202  case TEK_Aggregate:
203  if (!ignoreResult && aggSlot.isIgnored())
204  aggSlot = CreateAggTemp(E->getType(), "agg-temp");
205  EmitAggExpr(E, aggSlot);
206  return aggSlot.asRValue();
207  }
208  llvm_unreachable("bad evaluation kind");
209 }
210 
211 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
212 /// always be accessible even if no aggregate location is provided.
215 
217  AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
218  return EmitAnyExpr(E, AggSlot);
219 }
220 
221 /// EmitAnyExprToMem - Evaluate an expression into a given memory
222 /// location.
224  Address Location,
225  Qualifiers Quals,
226  bool IsInit) {
227  // FIXME: This function should take an LValue as an argument.
228  switch (getEvaluationKind(E->getType())) {
229  case TEK_Complex:
231  /*isInit*/ false);
232  return;
233 
234  case TEK_Aggregate: {
235  EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
238  AggValueSlot::IsAliased_t(!IsInit),
240  return;
241  }
242 
243  case TEK_Scalar: {
244  RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
245  LValue LV = MakeAddrLValue(Location, E->getType());
246  EmitStoreThroughLValue(RV, LV);
247  return;
248  }
249  }
250  llvm_unreachable("bad evaluation kind");
251 }
252 
253 static void
255  const Expr *E, Address ReferenceTemporary) {
256  // Objective-C++ ARC:
257  // If we are binding a reference to a temporary that has ownership, we
258  // need to perform retain/release operations on the temporary.
259  //
260  // FIXME: This should be looking at E, not M.
261  if (auto Lifetime = M->getType().getObjCLifetime()) {
262  switch (Lifetime) {
265  // Carry on to normal cleanup handling.
266  break;
267 
269  // Nothing to do; cleaned up by an autorelease pool.
270  return;
271 
274  switch (StorageDuration Duration = M->getStorageDuration()) {
275  case SD_Static:
276  // Note: we intentionally do not register a cleanup to release
277  // the object on program termination.
278  return;
279 
280  case SD_Thread:
281  // FIXME: We should probably register a cleanup in this case.
282  return;
283 
284  case SD_Automatic:
285  case SD_FullExpression:
288  if (Lifetime == Qualifiers::OCL_Strong) {
289  const ValueDecl *VD = M->getExtendingDecl();
290  bool Precise =
291  VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
292  CleanupKind = CGF.getARCCleanupKind();
293  Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
295  } else {
296  // __weak objects always get EH cleanups; otherwise, exceptions
297  // could cause really nasty crashes instead of mere leaks.
298  CleanupKind = NormalAndEHCleanup;
300  }
301  if (Duration == SD_FullExpression)
302  CGF.pushDestroy(CleanupKind, ReferenceTemporary,
303  M->getType(), *Destroy,
304  CleanupKind & EHCleanup);
305  else
306  CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
307  M->getType(),
308  *Destroy, CleanupKind & EHCleanup);
309  return;
310 
311  case SD_Dynamic:
312  llvm_unreachable("temporary cannot have dynamic storage duration");
313  }
314  llvm_unreachable("unknown storage duration");
315  }
316  }
317 
318  CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
319  if (const RecordType *RT =
321  // Get the destructor for the reference temporary.
322  auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
323  if (!ClassDecl->hasTrivialDestructor())
324  ReferenceTemporaryDtor = ClassDecl->getDestructor();
325  }
326 
327  if (!ReferenceTemporaryDtor)
328  return;
329 
330  // Call the destructor for the temporary.
331  switch (M->getStorageDuration()) {
332  case SD_Static:
333  case SD_Thread: {
334  llvm::FunctionCallee CleanupFn;
335  llvm::Constant *CleanupArg;
336  if (E->getType()->isArrayType()) {
337  CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
338  ReferenceTemporary, E->getType(),
340  dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
341  CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
342  } else {
343  CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
344  GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
345  CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
346  }
348  CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
349  break;
350  }
351 
352  case SD_FullExpression:
353  CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
355  CGF.getLangOpts().Exceptions);
356  break;
357 
358  case SD_Automatic:
360  ReferenceTemporary, E->getType(),
362  CGF.getLangOpts().Exceptions);
363  break;
364 
365  case SD_Dynamic:
366  llvm_unreachable("temporary cannot have dynamic storage duration");
367  }
368 }
369 
371  const MaterializeTemporaryExpr *M,
372  const Expr *Inner,
373  Address *Alloca = nullptr) {
374  auto &TCG = CGF.getTargetHooks();
375  switch (M->getStorageDuration()) {
376  case SD_FullExpression:
377  case SD_Automatic: {
378  // If we have a constant temporary array or record try to promote it into a
379  // constant global under the same rules a normal constant would've been
380  // promoted. This is easier on the optimizer and generally emits fewer
381  // instructions.
382  QualType Ty = Inner->getType();
383  if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
384  (Ty->isArrayType() || Ty->isRecordType()) &&
385  CGF.CGM.isTypeConstant(Ty, true))
386  if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
387  if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
388  auto AS = AddrSpace.getValue();
389  auto *GV = new llvm::GlobalVariable(
390  CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
391  llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
392  llvm::GlobalValue::NotThreadLocal,
394  CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
395  GV->setAlignment(alignment.getQuantity());
396  llvm::Constant *C = GV;
397  if (AS != LangAS::Default)
398  C = TCG.performAddrSpaceCast(
399  CGF.CGM, GV, AS, LangAS::Default,
400  GV->getValueType()->getPointerTo(
402  // FIXME: Should we put the new global into a COMDAT?
403  return Address(C, alignment);
404  }
405  }
406  return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
407  }
408  case SD_Thread:
409  case SD_Static:
410  return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
411 
412  case SD_Dynamic:
413  llvm_unreachable("temporary can't have dynamic storage duration");
414  }
415  llvm_unreachable("unknown storage duration");
416 }
417 
420  const Expr *E = M->GetTemporaryExpr();
421 
422  assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
423  !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
424  "Reference should never be pseudo-strong!");
425 
426  // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
427  // as that will cause the lifetime adjustment to be lost for ARC
428  auto ownership = M->getType().getObjCLifetime();
429  if (ownership != Qualifiers::OCL_None &&
430  ownership != Qualifiers::OCL_ExplicitNone) {
431  Address Object = createReferenceTemporary(*this, M, E);
432  if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
433  Object = Address(llvm::ConstantExpr::getBitCast(Var,
435  ->getPointerTo(Object.getAddressSpace())),
436  Object.getAlignment());
437 
438  // createReferenceTemporary will promote the temporary to a global with a
439  // constant initializer if it can. It can only do this to a value of
440  // ARC-manageable type if the value is global and therefore "immune" to
441  // ref-counting operations. Therefore we have no need to emit either a
442  // dynamic initialization or a cleanup and we can just return the address
443  // of the temporary.
444  if (Var->hasInitializer())
445  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
446 
447  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
448  }
449  LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
451 
452  switch (getEvaluationKind(E->getType())) {
453  default: llvm_unreachable("expected scalar or aggregate expression");
454  case TEK_Scalar:
455  EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
456  break;
457  case TEK_Aggregate: {
459  E->getType().getQualifiers(),
464  break;
465  }
466  }
467 
468  pushTemporaryCleanup(*this, M, E, Object);
469  return RefTempDst;
470  }
471 
474  E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
475 
476  for (const auto &Ignored : CommaLHSs)
477  EmitIgnoredExpr(Ignored);
478 
479  if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
480  if (opaque->getType()->isRecordType()) {
481  assert(Adjustments.empty());
482  return EmitOpaqueValueLValue(opaque);
483  }
484  }
485 
486  // Create and initialize the reference temporary.
487  Address Alloca = Address::invalid();
488  Address Object = createReferenceTemporary(*this, M, E, &Alloca);
489  if (auto *Var = dyn_cast<llvm::GlobalVariable>(
490  Object.getPointer()->stripPointerCasts())) {
491  Object = Address(llvm::ConstantExpr::getBitCast(
492  cast<llvm::Constant>(Object.getPointer()),
493  ConvertTypeForMem(E->getType())->getPointerTo()),
494  Object.getAlignment());
495  // If the temporary is a global and has a constant initializer or is a
496  // constant temporary that we promoted to a global, we may have already
497  // initialized it.
498  if (!Var->hasInitializer()) {
499  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
500  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
501  }
502  } else {
503  switch (M->getStorageDuration()) {
504  case SD_Automatic:
505  if (auto *Size = EmitLifetimeStart(
506  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
507  Alloca.getPointer())) {
508  pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
509  Alloca, Size);
510  }
511  break;
512 
513  case SD_FullExpression: {
514  if (!ShouldEmitLifetimeMarkers)
515  break;
516 
517  // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
518  // marker. Instead, start the lifetime of a conditional temporary earlier
519  // so that it's unconditional. Don't do this in ASan's use-after-scope
520  // mode so that it gets the more precise lifetime marks. If the type has
521  // a non-trivial destructor, we'll have a cleanup block for it anyway,
522  // so this typically doesn't help; skip it in that case.
523  ConditionalEvaluation *OldConditional = nullptr;
524  CGBuilderTy::InsertPoint OldIP;
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 
647  return SanOpts.has(SanitizerKind::Null) |
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 =
681  dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
682 
683  llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
684  llvm::Value *IsNonNull = nullptr;
685  bool IsGuaranteedNonNull =
686  SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
687  bool AllowNullPointers = isNullPointerAllowed(TCK);
688  if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
689  !IsGuaranteedNonNull) {
690  // The glvalue must not be an empty glvalue.
691  IsNonNull = Builder.CreateIsNotNull(Ptr);
692 
693  // The IR builder can constant-fold the null check if the pointer points to
694  // a constant.
695  IsGuaranteedNonNull = IsNonNull == True;
696 
697  // Skip the null check if the pointer is known to be non-null.
698  if (!IsGuaranteedNonNull) {
699  if (AllowNullPointers) {
700  // When performing pointer casts, it's OK if the value is null.
701  // Skip the remaining checks in that case.
702  Done = createBasicBlock("null");
703  llvm::BasicBlock *Rest = createBasicBlock("not.null");
704  Builder.CreateCondBr(IsNonNull, Rest, Done);
705  EmitBlock(Rest);
706  } else {
707  Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
708  }
709  }
710  }
711 
712  if (SanOpts.has(SanitizerKind::ObjectSize) &&
713  !SkippedChecks.has(SanitizerKind::ObjectSize) &&
714  !Ty->isIncompleteType()) {
715  uint64_t TySize = getContext().getTypeSizeInChars(Ty).getQuantity();
716  llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
717  if (ArraySize)
718  Size = Builder.CreateMul(Size, ArraySize);
719 
720  // Degenerate case: new X[0] does not need an objectsize check.
721  llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
722  if (!ConstantSize || !ConstantSize->isNullValue()) {
723  // The glvalue must refer to a large enough storage region.
724  // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
725  // to check this.
726  // FIXME: Get object address space
727  llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
728  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
729  llvm::Value *Min = Builder.getFalse();
730  llvm::Value *NullIsUnknown = Builder.getFalse();
731  llvm::Value *Dynamic = Builder.getFalse();
732  llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
733  llvm::Value *LargeEnough = Builder.CreateICmpUGE(
734  Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
735  Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
736  }
737  }
738 
739  uint64_t AlignVal = 0;
740  llvm::Value *PtrAsInt = nullptr;
741 
742  if (SanOpts.has(SanitizerKind::Alignment) &&
743  !SkippedChecks.has(SanitizerKind::Alignment)) {
744  AlignVal = Alignment.getQuantity();
745  if (!Ty->isIncompleteType() && !AlignVal)
746  AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
747 
748  // The glvalue must be suitably aligned.
749  if (AlignVal > 1 &&
750  (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
751  PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
752  llvm::Value *Align = Builder.CreateAnd(
753  PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
754  llvm::Value *Aligned =
755  Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
756  if (Aligned != True)
757  Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
758  }
759  }
760 
761  if (Checks.size() > 0) {
762  // Make sure we're not losing information. Alignment needs to be a power of
763  // 2
764  assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
765  llvm::Constant *StaticData[] = {
767  llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
768  llvm::ConstantInt::get(Int8Ty, TCK)};
769  EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
770  PtrAsInt ? PtrAsInt : Ptr);
771  }
772 
773  // If possible, check that the vptr indicates that there is a subobject of
774  // type Ty at offset zero within this object.
775  //
776  // C++11 [basic.life]p5,6:
777  // [For storage which does not refer to an object within its lifetime]
778  // The program has undefined behavior if:
779  // -- the [pointer or glvalue] is used to access a non-static data member
780  // or call a non-static member function
781  if (SanOpts.has(SanitizerKind::Vptr) &&
782  !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
783  // Ensure that the pointer is non-null before loading it. If there is no
784  // compile-time guarantee, reuse the run-time null check or emit a new one.
785  if (!IsGuaranteedNonNull) {
786  if (!IsNonNull)
787  IsNonNull = Builder.CreateIsNotNull(Ptr);
788  if (!Done)
789  Done = createBasicBlock("vptr.null");
790  llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
791  Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
792  EmitBlock(VptrNotNull);
793  }
794 
795  // Compute a hash of the mangled name of the type.
796  //
797  // FIXME: This is not guaranteed to be deterministic! Move to a
798  // fingerprinting mechanism once LLVM provides one. For the time
799  // being the implementation happens to be deterministic.
800  SmallString<64> MangledName;
801  llvm::raw_svector_ostream Out(MangledName);
803  Out);
804 
805  // Blacklist based on the mangled type.
807  SanitizerKind::Vptr, Out.str())) {
808  llvm::hash_code TypeHash = hash_value(Out.str());
809 
810  // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
811  llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
812  llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
813  Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
814  llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
815  llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
816 
817  llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
818  Hash = Builder.CreateTrunc(Hash, IntPtrTy);
819 
820  // Look the hash up in our cache.
821  const int CacheSize = 128;
822  llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
824  "__ubsan_vptr_type_cache");
825  llvm::Value *Slot = Builder.CreateAnd(Hash,
826  llvm::ConstantInt::get(IntPtrTy,
827  CacheSize-1));
828  llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
829  llvm::Value *CacheVal =
830  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
831  getPointerAlign());
832 
833  // If the hash isn't in the cache, call a runtime handler to perform the
834  // hard work of checking whether the vptr is for an object of the right
835  // type. This will either fill in the cache and return, or produce a
836  // diagnostic.
837  llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
838  llvm::Constant *StaticData[] = {
842  llvm::ConstantInt::get(Int8Ty, TCK)
843  };
844  llvm::Value *DynamicData[] = { Ptr, Hash };
845  EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
846  SanitizerHandler::DynamicTypeCacheMiss, StaticData,
847  DynamicData);
848  }
849  }
850 
851  if (Done) {
852  Builder.CreateBr(Done);
853  EmitBlock(Done);
854  }
855 }
856 
857 /// Determine whether this expression refers to a flexible array member in a
858 /// struct. We disable array bounds checks for such members.
859 static bool isFlexibleArrayMemberExpr(const Expr *E) {
860  // For compatibility with existing code, we treat arrays of length 0 or
861  // 1 as flexible array members.
862  const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
863  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
864  if (CAT->getSize().ugt(1))
865  return false;
866  } else if (!isa<IncompleteArrayType>(AT))
867  return false;
868 
869  E = E->IgnoreParens();
870 
871  // A flexible array member must be the last member in the class.
872  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
873  // FIXME: If the base type of the member expr is not FD->getParent(),
874  // this should not be treated as a flexible array member access.
875  if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
877  DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
878  return ++FI == FD->getParent()->field_end();
879  }
880  } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
881  return IRE->getDecl()->getNextIvar() == nullptr;
882  }
883 
884  return false;
885 }
886 
888  QualType EltTy) {
889  ASTContext &C = getContext();
890  uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
891  if (!EltSize)
892  return nullptr;
893 
894  auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
895  if (!ArrayDeclRef)
896  return nullptr;
897 
898  auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
899  if (!ParamDecl)
900  return nullptr;
901 
902  auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
903  if (!POSAttr)
904  return nullptr;
905 
906  // Don't load the size if it's a lower bound.
907  int POSType = POSAttr->getType();
908  if (POSType != 0 && POSType != 1)
909  return nullptr;
910 
911  // Find the implicit size parameter.
912  auto PassedSizeIt = SizeArguments.find(ParamDecl);
913  if (PassedSizeIt == SizeArguments.end())
914  return nullptr;
915 
916  const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
917  assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
918  Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
919  llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
920  C.getSizeType(), E->getExprLoc());
921  llvm::Value *SizeOfElement =
922  llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
923  return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
924 }
925 
926 /// If Base is known to point to the start of an array, return the length of
927 /// that array. Return 0 if the length cannot be determined.
929  CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
930  // For the vector indexing extension, the bound is the number of elements.
931  if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
932  IndexedType = Base->getType();
933  return CGF.Builder.getInt32(VT->getNumElements());
934  }
935 
936  Base = Base->IgnoreParens();
937 
938  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
939  if (CE->getCastKind() == CK_ArrayToPointerDecay &&
940  !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
941  IndexedType = CE->getSubExpr()->getType();
942  const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
943  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
944  return CGF.Builder.getInt(CAT->getSize());
945  else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
946  return CGF.getVLASize(VAT).NumElts;
947  // Ignore pass_object_size here. It's not applicable on decayed pointers.
948  }
949  }
950 
951  QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
952  if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
953  IndexedType = Base->getType();
954  return POS;
955  }
956 
957  return nullptr;
958 }
959 
961  llvm::Value *Index, QualType IndexType,
962  bool Accessed) {
963  assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
964  "should not be called unless adding bounds checks");
965  SanitizerScope SanScope(this);
966 
967  QualType IndexedType;
968  llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
969  if (!Bound)
970  return;
971 
972  bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
973  llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
974  llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
975 
976  llvm::Constant *StaticData[] = {
978  EmitCheckTypeDescriptor(IndexedType),
979  EmitCheckTypeDescriptor(IndexType)
980  };
981  llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
982  : Builder.CreateICmpULE(IndexVal, BoundVal);
983  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
984  SanitizerHandler::OutOfBounds, StaticData, Index);
985 }
986 
987 
990  bool isInc, bool isPre) {
991  ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
992 
993  llvm::Value *NextVal;
994  if (isa<llvm::IntegerType>(InVal.first->getType())) {
995  uint64_t AmountVal = isInc ? 1 : -1;
996  NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
997 
998  // Add the inc/dec to the real part.
999  NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1000  } else {
1001  QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
1002  llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1003  if (!isInc)
1004  FVal.changeSign();
1005  NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1006 
1007  // Add the inc/dec to the real part.
1008  NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1009  }
1010 
1011  ComplexPairTy IncVal(NextVal, InVal.second);
1012 
1013  // Store the updated result through the lvalue.
1014  EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1015 
1016  // If this is a postinc, return the value read from memory, otherwise use the
1017  // updated value.
1018  return isPre ? IncVal : InVal;
1019 }
1020 
1022  CodeGenFunction *CGF) {
1023  // Bind VLAs in the cast type.
1024  if (CGF && E->getType()->isVariablyModifiedType())
1025  CGF->EmitVariablyModifiedType(E->getType());
1026 
1027  if (CGDebugInfo *DI = getModuleDebugInfo())
1028  DI->EmitExplicitCastType(E->getType());
1029 }
1030 
1031 //===----------------------------------------------------------------------===//
1032 // LValue Expression Emission
1033 //===----------------------------------------------------------------------===//
1034 
1035 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1036 /// derive a more accurate bound on the alignment of the pointer.
1038  LValueBaseInfo *BaseInfo,
1039  TBAAAccessInfo *TBAAInfo) {
1040  // We allow this with ObjC object pointers because of fragile ABIs.
1041  assert(E->getType()->isPointerType() ||
1043  E = E->IgnoreParens();
1044 
1045  // Casts:
1046  if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1047  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1048  CGM.EmitExplicitCastExprType(ECE, this);
1049 
1050  switch (CE->getCastKind()) {
1051  // Non-converting casts (but not C's implicit conversion from void*).
1052  case CK_BitCast:
1053  case CK_NoOp:
1054  case CK_AddressSpaceConversion:
1055  if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1056  if (PtrTy->getPointeeType()->isVoidType())
1057  break;
1058 
1059  LValueBaseInfo InnerBaseInfo;
1060  TBAAAccessInfo InnerTBAAInfo;
1061  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1062  &InnerBaseInfo,
1063  &InnerTBAAInfo);
1064  if (BaseInfo) *BaseInfo = InnerBaseInfo;
1065  if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1066 
1067  if (isa<ExplicitCastExpr>(CE)) {
1068  LValueBaseInfo TargetTypeBaseInfo;
1069  TBAAAccessInfo TargetTypeTBAAInfo;
1070  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1071  &TargetTypeBaseInfo,
1072  &TargetTypeTBAAInfo);
1073  if (TBAAInfo)
1074  *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1075  TargetTypeTBAAInfo);
1076  // If the source l-value is opaque, honor the alignment of the
1077  // casted-to type.
1078  if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1079  if (BaseInfo)
1080  BaseInfo->mergeForCast(TargetTypeBaseInfo);
1081  Addr = Address(Addr.getPointer(), Align);
1082  }
1083  }
1084 
1085  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1086  CE->getCastKind() == CK_BitCast) {
1087  if (auto PT = E->getType()->getAs<PointerType>())
1088  EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1089  /*MayBeNull=*/true,
1091  CE->getBeginLoc());
1092  }
1093  return CE->getCastKind() != CK_AddressSpaceConversion
1094  ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1096  ConvertType(E->getType()));
1097  }
1098  break;
1099 
1100  // Array-to-pointer decay.
1101  case CK_ArrayToPointerDecay:
1102  return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1103 
1104  // Derived-to-base conversions.
1105  case CK_UncheckedDerivedToBase:
1106  case CK_DerivedToBase: {
1107  // TODO: Support accesses to members of base classes in TBAA. For now, we
1108  // conservatively pretend that the complete object is of the base class
1109  // type.
1110  if (TBAAInfo)
1111  *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1112  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1113  auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1114  return GetAddressOfBaseClass(Addr, Derived,
1115  CE->path_begin(), CE->path_end(),
1117  CE->getExprLoc());
1118  }
1119 
1120  // TODO: Is there any reason to treat base-to-derived conversions
1121  // specially?
1122  default:
1123  break;
1124  }
1125  }
1126 
1127  // Unary &.
1128  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1129  if (UO->getOpcode() == UO_AddrOf) {
1130  LValue LV = EmitLValue(UO->getSubExpr());
1131  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1132  if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1133  return LV.getAddress();
1134  }
1135  }
1136 
1137  // TODO: conditional operators, comma.
1138 
1139  // Otherwise, use the alignment of the type.
1140  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1141  TBAAInfo);
1142  return Address(EmitScalarExpr(E), Align);
1143 }
1144 
1146  if (Ty->isVoidType())
1147  return RValue::get(nullptr);
1148 
1149  switch (getEvaluationKind(Ty)) {
1150  case TEK_Complex: {
1151  llvm::Type *EltTy =
1153  llvm::Value *U = llvm::UndefValue::get(EltTy);
1154  return RValue::getComplex(std::make_pair(U, U));
1155  }
1156 
1157  // If this is a use of an undefined aggregate type, the aggregate must have an
1158  // identifiable address. Just because the contents of the value are undefined
1159  // doesn't mean that the address can't be taken and compared.
1160  case TEK_Aggregate: {
1161  Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1162  return RValue::getAggregate(DestPtr);
1163  }
1164 
1165  case TEK_Scalar:
1166  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1167  }
1168  llvm_unreachable("bad evaluation kind");
1169 }
1170 
1172  const char *Name) {
1173  ErrorUnsupported(E, Name);
1174  return GetUndefRValue(E->getType());
1175 }
1176 
1178  const char *Name) {
1179  ErrorUnsupported(E, Name);
1180  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1181  return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1182  E->getType());
1183 }
1184 
1186  const Expr *Base = Obj;
1187  while (!isa<CXXThisExpr>(Base)) {
1188  // The result of a dynamic_cast can be null.
1189  if (isa<CXXDynamicCastExpr>(Base))
1190  return false;
1191 
1192  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1193  Base = CE->getSubExpr();
1194  } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1195  Base = PE->getSubExpr();
1196  } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1197  if (UO->getOpcode() == UO_Extension)
1198  Base = UO->getSubExpr();
1199  else
1200  return false;
1201  } else {
1202  return false;
1203  }
1204  }
1205  return true;
1206 }
1207 
1209  LValue LV;
1210  if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1211  LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1212  else
1213  LV = EmitLValue(E);
1214  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1215  SanitizerSet SkippedChecks;
1216  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1217  bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1218  if (IsBaseCXXThis)
1219  SkippedChecks.set(SanitizerKind::Alignment, true);
1220  if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1221  SkippedChecks.set(SanitizerKind::Null, true);
1222  }
1223  EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1224  E->getType(), LV.getAlignment(), SkippedChecks);
1225  }
1226  return LV;
1227 }
1228 
1229 /// EmitLValue - Emit code to compute a designator that specifies the location
1230 /// of the expression.
1231 ///
1232 /// This can return one of two things: a simple address or a bitfield reference.
1233 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1234 /// an LLVM pointer type.
1235 ///
1236 /// If this returns a bitfield reference, nothing about the pointee type of the
1237 /// LLVM value is known: For example, it may not be a pointer to an integer.
1238 ///
1239 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1240 /// this method guarantees that the returned pointer type will point to an LLVM
1241 /// type of the same size of the lvalue's type. If the lvalue has a variable
1242 /// length type, this is not possible.
1243 ///
1245  ApplyDebugLocation DL(*this, E);
1246  switch (E->getStmtClass()) {
1247  default: return EmitUnsupportedLValue(E, "l-value expression");
1248 
1249  case Expr::ObjCPropertyRefExprClass:
1250  llvm_unreachable("cannot emit a property reference directly");
1251 
1252  case Expr::ObjCSelectorExprClass:
1253  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1254  case Expr::ObjCIsaExprClass:
1255  return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1256  case Expr::BinaryOperatorClass:
1257  return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1258  case Expr::CompoundAssignOperatorClass: {
1259  QualType Ty = E->getType();
1260  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1261  Ty = AT->getValueType();
1262  if (!Ty->isAnyComplexType())
1263  return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1264  return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1265  }
1266  case Expr::CallExprClass:
1267  case Expr::CXXMemberCallExprClass:
1268  case Expr::CXXOperatorCallExprClass:
1269  case Expr::UserDefinedLiteralClass:
1270  return EmitCallExprLValue(cast<CallExpr>(E));
1271  case Expr::VAArgExprClass:
1272  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1273  case Expr::DeclRefExprClass:
1274  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1275  case Expr::ConstantExprClass:
1276  return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1277  case Expr::ParenExprClass:
1278  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1279  case Expr::GenericSelectionExprClass:
1280  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1281  case Expr::PredefinedExprClass:
1282  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1283  case Expr::StringLiteralClass:
1284  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1285  case Expr::ObjCEncodeExprClass:
1286  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1287  case Expr::PseudoObjectExprClass:
1288  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1289  case Expr::InitListExprClass:
1290  return EmitInitListLValue(cast<InitListExpr>(E));
1291  case Expr::CXXTemporaryObjectExprClass:
1292  case Expr::CXXConstructExprClass:
1293  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1294  case Expr::CXXBindTemporaryExprClass:
1295  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1296  case Expr::CXXUuidofExprClass:
1297  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1298  case Expr::LambdaExprClass:
1299  return EmitAggExprToLValue(E);
1300 
1301  case Expr::ExprWithCleanupsClass: {
1302  const auto *cleanups = cast<ExprWithCleanups>(E);
1303  enterFullExpression(cleanups);
1304  RunCleanupsScope Scope(*this);
1305  LValue LV = EmitLValue(cleanups->getSubExpr());
1306  if (LV.isSimple()) {
1307  // Defend against branches out of gnu statement expressions surrounded by
1308  // cleanups.
1309  llvm::Value *V = LV.getPointer();
1310  Scope.ForceCleanup({&V});
1311  return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1312  getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1313  }
1314  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1315  // bitfield lvalue or some other non-simple lvalue?
1316  return LV;
1317  }
1318 
1319  case Expr::CXXDefaultArgExprClass: {
1320  auto *DAE = cast<CXXDefaultArgExpr>(E);
1321  CXXDefaultArgExprScope Scope(*this, DAE);
1322  return EmitLValue(DAE->getExpr());
1323  }
1324  case Expr::CXXDefaultInitExprClass: {
1325  auto *DIE = cast<CXXDefaultInitExpr>(E);
1326  CXXDefaultInitExprScope Scope(*this, DIE);
1327  return EmitLValue(DIE->getExpr());
1328  }
1329  case Expr::CXXTypeidExprClass:
1330  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1331 
1332  case Expr::ObjCMessageExprClass:
1333  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1334  case Expr::ObjCIvarRefExprClass:
1335  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1336  case Expr::StmtExprClass:
1337  return EmitStmtExprLValue(cast<StmtExpr>(E));
1338  case Expr::UnaryOperatorClass:
1339  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1340  case Expr::ArraySubscriptExprClass:
1341  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1342  case Expr::OMPArraySectionExprClass:
1343  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1344  case Expr::ExtVectorElementExprClass:
1345  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1346  case Expr::MemberExprClass:
1347  return EmitMemberExpr(cast<MemberExpr>(E));
1348  case Expr::CompoundLiteralExprClass:
1349  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1350  case Expr::ConditionalOperatorClass:
1351  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1352  case Expr::BinaryConditionalOperatorClass:
1353  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1354  case Expr::ChooseExprClass:
1355  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1356  case Expr::OpaqueValueExprClass:
1357  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1358  case Expr::SubstNonTypeTemplateParmExprClass:
1359  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1360  case Expr::ImplicitCastExprClass:
1361  case Expr::CStyleCastExprClass:
1362  case Expr::CXXFunctionalCastExprClass:
1363  case Expr::CXXStaticCastExprClass:
1364  case Expr::CXXDynamicCastExprClass:
1365  case Expr::CXXReinterpretCastExprClass:
1366  case Expr::CXXConstCastExprClass:
1367  case Expr::ObjCBridgedCastExprClass:
1368  return EmitCastLValue(cast<CastExpr>(E));
1369 
1370  case Expr::MaterializeTemporaryExprClass:
1371  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1372 
1373  case Expr::CoawaitExprClass:
1374  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1375  case Expr::CoyieldExprClass:
1376  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1377  }
1378 }
1379 
1380 /// Given an object of the given canonical type, can we safely copy a
1381 /// value out of it based on its initializer?
1383  assert(type.isCanonical());
1384  assert(!type->isReferenceType());
1385 
1386  // Must be const-qualified but non-volatile.
1387  Qualifiers qs = type.getLocalQualifiers();
1388  if (!qs.hasConst() || qs.hasVolatile()) return false;
1389 
1390  // Otherwise, all object types satisfy this except C++ classes with
1391  // mutable subobjects or non-trivial copy/destroy behavior.
1392  if (const auto *RT = dyn_cast<RecordType>(type))
1393  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1394  if (RD->hasMutableFields() || !RD->isTrivial())
1395  return false;
1396 
1397  return true;
1398 }
1399 
1400 /// Can we constant-emit a load of a reference to a variable of the
1401 /// given type? This is different from predicates like
1402 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1403 /// in situations that don't necessarily satisfy the language's rules
1404 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1405 /// to do this with const float variables even if those variables
1406 /// aren't marked 'constexpr'.
1412 };
1414  type = type.getCanonicalType();
1415  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1416  if (isConstantEmittableObjectType(ref->getPointeeType()))
1417  return CEK_AsValueOrReference;
1418  return CEK_AsReferenceOnly;
1419  }
1421  return CEK_AsValueOnly;
1422  return CEK_None;
1423 }
1424 
1425 /// Try to emit a reference to the given value without producing it as
1426 /// an l-value. This is just an optimization, but it avoids us needing
1427 /// to emit global copies of variables if they're named without triggering
1428 /// a formal use in a context where we can't emit a direct reference to them,
1429 /// for instance if a block or lambda or a member of a local class uses a
1430 /// const int variable or constexpr variable from an enclosing function.
1433  ValueDecl *value = refExpr->getDecl();
1434 
1435  // The value needs to be an enum constant or a constant variable.
1437  if (isa<ParmVarDecl>(value)) {
1438  CEK = CEK_None;
1439  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1440  CEK = checkVarTypeForConstantEmission(var->getType());
1441  } else if (isa<EnumConstantDecl>(value)) {
1442  CEK = CEK_AsValueOnly;
1443  } else {
1444  CEK = CEK_None;
1445  }
1446  if (CEK == CEK_None) return ConstantEmission();
1447 
1449  bool resultIsReference;
1450  QualType resultType;
1451 
1452  // It's best to evaluate all the way as an r-value if that's permitted.
1453  if (CEK != CEK_AsReferenceOnly &&
1454  refExpr->EvaluateAsRValue(result, getContext())) {
1455  resultIsReference = false;
1456  resultType = refExpr->getType();
1457 
1458  // Otherwise, try to evaluate as an l-value.
1459  } else if (CEK != CEK_AsValueOnly &&
1460  refExpr->EvaluateAsLValue(result, getContext())) {
1461  resultIsReference = true;
1462  resultType = value->getType();
1463 
1464  // Failure.
1465  } else {
1466  return ConstantEmission();
1467  }
1468 
1469  // In any case, if the initializer has side-effects, abandon ship.
1470  if (result.HasSideEffects)
1471  return ConstantEmission();
1472 
1473  // Emit as a constant.
1474  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1475  result.Val, resultType);
1476 
1477  // Make sure we emit a debug reference to the global variable.
1478  // This should probably fire even for
1479  if (isa<VarDecl>(value)) {
1480  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1481  EmitDeclRefExprDbgValue(refExpr, result.Val);
1482  } else {
1483  assert(isa<EnumConstantDecl>(value));
1484  EmitDeclRefExprDbgValue(refExpr, result.Val);
1485  }
1486 
1487  // If we emitted a reference constant, we need to dereference that.
1488  if (resultIsReference)
1490 
1491  return ConstantEmission::forValue(C);
1492 }
1493 
1495  const MemberExpr *ME) {
1496  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1497  // Try to emit static variable member expressions as DREs.
1498  return DeclRefExpr::Create(
1500  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1501  ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1502  }
1503  return nullptr;
1504 }
1505 
1508  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1509  return tryEmitAsConstant(DRE);
1510  return ConstantEmission();
1511 }
1512 
1514  const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1515  assert(Constant && "not a constant");
1516  if (Constant.isReference())
1517  return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1518  E->getExprLoc())
1519  .getScalarVal();
1520  return Constant.getValue();
1521 }
1522 
1524  SourceLocation Loc) {
1525  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1526  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1527  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1528 }
1529 
1531  if (Ty->isBooleanType())
1532  return true;
1533 
1534  if (const EnumType *ET = Ty->getAs<EnumType>())
1535  return ET->getDecl()->getIntegerType()->isBooleanType();
1536 
1537  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1538  return hasBooleanRepresentation(AT->getValueType());
1539 
1540  return false;
1541 }
1542 
1544  llvm::APInt &Min, llvm::APInt &End,
1545  bool StrictEnums, bool IsBool) {
1546  const EnumType *ET = Ty->getAs<EnumType>();
1547  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1548  ET && !ET->getDecl()->isFixed();
1549  if (!IsBool && !IsRegularCPlusPlusEnum)
1550  return false;
1551 
1552  if (IsBool) {
1553  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1554  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1555  } else {
1556  const EnumDecl *ED = ET->getDecl();
1557  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1558  unsigned Bitwidth = LTy->getScalarSizeInBits();
1559  unsigned NumNegativeBits = ED->getNumNegativeBits();
1560  unsigned NumPositiveBits = ED->getNumPositiveBits();
1561 
1562  if (NumNegativeBits) {
1563  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1564  assert(NumBits <= Bitwidth);
1565  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1566  Min = -End;
1567  } else {
1568  assert(NumPositiveBits <= Bitwidth);
1569  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1570  Min = llvm::APInt(Bitwidth, 0);
1571  }
1572  }
1573  return true;
1574 }
1575 
1576 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1577  llvm::APInt Min, End;
1578  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1580  return nullptr;
1581 
1582  llvm::MDBuilder MDHelper(getLLVMContext());
1583  return MDHelper.createRange(Min, End);
1584 }
1585 
1587  SourceLocation Loc) {
1588  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1589  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1590  if (!HasBoolCheck && !HasEnumCheck)
1591  return false;
1592 
1593  bool IsBool = hasBooleanRepresentation(Ty) ||
1594  NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1595  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1596  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1597  if (!NeedsBoolCheck && !NeedsEnumCheck)
1598  return false;
1599 
1600  // Single-bit booleans don't need to be checked. Special-case this to avoid
1601  // a bit width mismatch when handling bitfield values. This is handled by
1602  // EmitFromMemory for the non-bitfield case.
1603  if (IsBool &&
1604  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1605  return false;
1606 
1607  llvm::APInt Min, End;
1608  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1609  return true;
1610 
1611  auto &Ctx = getLLVMContext();
1612  SanitizerScope SanScope(this);
1613  llvm::Value *Check;
1614  --End;
1615  if (!Min) {
1616  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1617  } else {
1618  llvm::Value *Upper =
1619  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1620  llvm::Value *Lower =
1621  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1622  Check = Builder.CreateAnd(Upper, Lower);
1623  }
1624  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1627  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1628  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1629  StaticArgs, EmitCheckValue(Value));
1630  return true;
1631 }
1632 
1634  QualType Ty,
1635  SourceLocation Loc,
1636  LValueBaseInfo BaseInfo,
1637  TBAAAccessInfo TBAAInfo,
1638  bool isNontemporal) {
1639  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1640  // For better performance, handle vector loads differently.
1641  if (Ty->isVectorType()) {
1642  const llvm::Type *EltTy = Addr.getElementType();
1643 
1644  const auto *VTy = cast<llvm::VectorType>(EltTy);
1645 
1646  // Handle vectors of size 3 like size 4 for better performance.
1647  if (VTy->getNumElements() == 3) {
1648 
1649  // Bitcast to vec4 type.
1650  llvm::VectorType *vec4Ty =
1651  llvm::VectorType::get(VTy->getElementType(), 4);
1652  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1653  // Now load value.
1654  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1655 
1656  // Shuffle vector to get vec3.
1657  V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1658  {0, 1, 2}, "extractVec");
1659  return EmitFromMemory(V, Ty);
1660  }
1661  }
1662  }
1663 
1664  // Atomic operations have to be done on integral types.
1665  LValue AtomicLValue =
1666  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1667  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1668  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1669  }
1670 
1671  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1672  if (isNontemporal) {
1673  llvm::MDNode *Node = llvm::MDNode::get(
1674  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1675  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1676  }
1677 
1678  CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1679 
1680  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1681  // In order to prevent the optimizer from throwing away the check, don't
1682  // attach range metadata to the load.
1683  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1684  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1685  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1686 
1687  return EmitFromMemory(Load, Ty);
1688 }
1689 
1691  // Bool has a different representation in memory than in registers.
1692  if (hasBooleanRepresentation(Ty)) {
1693  // This should really always be an i1, but sometimes it's already
1694  // an i8, and it's awkward to track those cases down.
1695  if (Value->getType()->isIntegerTy(1))
1696  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1697  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1698  "wrong value rep of bool");
1699  }
1700 
1701  return Value;
1702 }
1703 
1705  // Bool has a different representation in memory than in registers.
1706  if (hasBooleanRepresentation(Ty)) {
1707  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1708  "wrong value rep of bool");
1709  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1710  }
1711 
1712  return Value;
1713 }
1714 
1716  bool Volatile, QualType Ty,
1717  LValueBaseInfo BaseInfo,
1718  TBAAAccessInfo TBAAInfo,
1719  bool isInit, bool isNontemporal) {
1720  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1721  // Handle vectors differently to get better performance.
1722  if (Ty->isVectorType()) {
1723  llvm::Type *SrcTy = Value->getType();
1724  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1725  // Handle vec3 special.
1726  if (VecTy && VecTy->getNumElements() == 3) {
1727  // Our source is a vec3, do a shuffle vector to make it a vec4.
1728  llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1729  Builder.getInt32(2),
1730  llvm::UndefValue::get(Builder.getInt32Ty())};
1731  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1732  Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1733  MaskV, "extractVec");
1734  SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1735  }
1736  if (Addr.getElementType() != SrcTy) {
1737  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1738  }
1739  }
1740  }
1741 
1742  Value = EmitToMemory(Value, Ty);
1743 
1744  LValue AtomicLValue =
1745  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1746  if (Ty->isAtomicType() ||
1747  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1748  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1749  return;
1750  }
1751 
1752  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1753  if (isNontemporal) {
1754  llvm::MDNode *Node =
1755  llvm::MDNode::get(Store->getContext(),
1756  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1757  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1758  }
1759 
1760  CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1761 }
1762 
1764  bool isInit) {
1765  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1766  lvalue.getType(), lvalue.getBaseInfo(),
1767  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1768 }
1769 
1770 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1771 /// method emits the address of the lvalue, then loads the result as an rvalue,
1772 /// returning the rvalue.
1774  if (LV.isObjCWeak()) {
1775  // load of a __weak object.
1776  Address AddrWeakObj = LV.getAddress();
1778  AddrWeakObj));
1779  }
1781  // In MRC mode, we do a load+autorelease.
1782  if (!getLangOpts().ObjCAutoRefCount) {
1783  return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1784  }
1785 
1786  // In ARC mode, we load retained and then consume the value.
1788  Object = EmitObjCConsumeObject(LV.getType(), Object);
1789  return RValue::get(Object);
1790  }
1791 
1792  if (LV.isSimple()) {
1793  assert(!LV.getType()->isFunctionType());
1794 
1795  // Everything needs a load.
1796  return RValue::get(EmitLoadOfScalar(LV, Loc));
1797  }
1798 
1799  if (LV.isVectorElt()) {
1800  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1801  LV.isVolatileQualified());
1802  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1803  "vecext"));
1804  }
1805 
1806  // If this is a reference to a subset of the elements of a vector, either
1807  // shuffle the input or extract/insert them as appropriate.
1808  if (LV.isExtVectorElt())
1810 
1811  // Global Register variables always invoke intrinsics
1812  if (LV.isGlobalReg())
1813  return EmitLoadOfGlobalRegLValue(LV);
1814 
1815  assert(LV.isBitField() && "Unknown LValue type!");
1816  return EmitLoadOfBitfieldLValue(LV, Loc);
1817 }
1818 
1820  SourceLocation Loc) {
1821  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1822 
1823  // Get the output type.
1824  llvm::Type *ResLTy = ConvertType(LV.getType());
1825 
1826  Address Ptr = LV.getBitFieldAddress();
1827  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1828 
1829  if (Info.IsSigned) {
1830  assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1831  unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1832  if (HighBits)
1833  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1834  if (Info.Offset + HighBits)
1835  Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1836  } else {
1837  if (Info.Offset)
1838  Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1839  if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1840  Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1841  Info.Size),
1842  "bf.clear");
1843  }
1844  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1845  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1846  return RValue::get(Val);
1847 }
1848 
1849 // If this is a reference to a subset of the elements of a vector, create an
1850 // appropriate shufflevector.
1853  LV.isVolatileQualified());
1854 
1855  const llvm::Constant *Elts = LV.getExtVectorElts();
1856 
1857  // If the result of the expression is a non-vector type, we must be extracting
1858  // a single element. Just codegen as an extractelement.
1859  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1860  if (!ExprVT) {
1861  unsigned InIdx = getAccessedFieldNo(0, Elts);
1862  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1863  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1864  }
1865 
1866  // Always use shuffle vector to try to retain the original program structure
1867  unsigned NumResultElts = ExprVT->getNumElements();
1868 
1870  for (unsigned i = 0; i != NumResultElts; ++i)
1871  Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1872 
1873  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1874  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1875  MaskV);
1876  return RValue::get(Vec);
1877 }
1878 
1879 /// Generates lvalue for partial ext_vector access.
1881  Address VectorAddress = LV.getExtVectorAddress();
1882  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1883  QualType EQT = ExprVT->getElementType();
1884  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1885 
1886  Address CastToPointerElement =
1887  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1888  "conv.ptr.element");
1889 
1890  const llvm::Constant *Elts = LV.getExtVectorElts();
1891  unsigned ix = getAccessedFieldNo(0, Elts);
1892 
1893  Address VectorBasePtrPlusIx =
1894  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1895  "vector.elt");
1896 
1897  return VectorBasePtrPlusIx;
1898 }
1899 
1900 /// Load of global gamed gegisters are always calls to intrinsics.
1902  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1903  "Bad type for register variable");
1904  llvm::MDNode *RegName = cast<llvm::MDNode>(
1905  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1906 
1907  // We accept integer and pointer types only
1908  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1909  llvm::Type *Ty = OrigTy;
1910  if (OrigTy->isPointerTy())
1911  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1912  llvm::Type *Types[] = { Ty };
1913 
1914  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1915  llvm::Value *Call = Builder.CreateCall(
1916  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1917  if (OrigTy->isPointerTy())
1918  Call = Builder.CreateIntToPtr(Call, OrigTy);
1919  return RValue::get(Call);
1920 }
1921 
1922 
1923 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1924 /// lvalue, where both are guaranteed to the have the same type, and that type
1925 /// is 'Ty'.
1927  bool isInit) {
1928  if (!Dst.isSimple()) {
1929  if (Dst.isVectorElt()) {
1930  // Read/modify/write the vector, inserting the new element.
1932  Dst.isVolatileQualified());
1933  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1934  Dst.getVectorIdx(), "vecins");
1936  Dst.isVolatileQualified());
1937  return;
1938  }
1939 
1940  // If this is an update of extended vector elements, insert them as
1941  // appropriate.
1942  if (Dst.isExtVectorElt())
1944 
1945  if (Dst.isGlobalReg())
1946  return EmitStoreThroughGlobalRegLValue(Src, Dst);
1947 
1948  assert(Dst.isBitField() && "Unknown LValue type");
1949  return EmitStoreThroughBitfieldLValue(Src, Dst);
1950  }
1951 
1952  // There's special magic for assigning into an ARC-qualified l-value.
1953  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1954  switch (Lifetime) {
1955  case Qualifiers::OCL_None:
1956  llvm_unreachable("present but none");
1957 
1959  // nothing special
1960  break;
1961 
1963  if (isInit) {
1964  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1965  break;
1966  }
1967  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1968  return;
1969 
1970  case Qualifiers::OCL_Weak:
1971  if (isInit)
1972  // Initialize and then skip the primitive store.
1973  EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1974  else
1975  EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1976  return;
1977 
1980  Src.getScalarVal()));
1981  // fall into the normal path
1982  break;
1983  }
1984  }
1985 
1986  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1987  // load of a __weak object.
1988  Address LvalueDst = Dst.getAddress();
1989  llvm::Value *src = Src.getScalarVal();
1990  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1991  return;
1992  }
1993 
1994  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1995  // load of a __strong object.
1996  Address LvalueDst = Dst.getAddress();
1997  llvm::Value *src = Src.getScalarVal();
1998  if (Dst.isObjCIvar()) {
1999  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2000  llvm::Type *ResultType = IntPtrTy;
2002  llvm::Value *RHS = dst.getPointer();
2003  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2004  llvm::Value *LHS =
2005  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2006  "sub.ptr.lhs.cast");
2007  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2008  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2009  BytesBetween);
2010  } else if (Dst.isGlobalObjCRef()) {
2011  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2012  Dst.isThreadLocalRef());
2013  }
2014  else
2015  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2016  return;
2017  }
2018 
2019  assert(Src.isScalar() && "Can't emit an agg store with this method");
2020  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2021 }
2022 
2024  llvm::Value **Result) {
2025  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2026  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2027  Address Ptr = Dst.getBitFieldAddress();
2028 
2029  // Get the source value, truncated to the width of the bit-field.
2030  llvm::Value *SrcVal = Src.getScalarVal();
2031 
2032  // Cast the source to the storage type and shift it into place.
2033  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2034  /*isSigned=*/false);
2035  llvm::Value *MaskedVal = SrcVal;
2036 
2037  // See if there are other bits in the bitfield's storage we'll need to load
2038  // and mask together with source before storing.
2039  if (Info.StorageSize != Info.Size) {
2040  assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
2041  llvm::Value *Val =
2042  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2043 
2044  // Mask the source value as needed.
2045  if (!hasBooleanRepresentation(Dst.getType()))
2046  SrcVal = Builder.CreateAnd(SrcVal,
2047  llvm::APInt::getLowBitsSet(Info.StorageSize,
2048  Info.Size),
2049  "bf.value");
2050  MaskedVal = SrcVal;
2051  if (Info.Offset)
2052  SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
2053 
2054  // Mask out the original value.
2055  Val = Builder.CreateAnd(Val,
2056  ~llvm::APInt::getBitsSet(Info.StorageSize,
2057  Info.Offset,
2058  Info.Offset + Info.Size),
2059  "bf.clear");
2060 
2061  // Or together the unchanged values and the source value.
2062  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2063  } else {
2064  assert(Info.Offset == 0);
2065  }
2066 
2067  // Write the new value back out.
2068  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2069 
2070  // Return the new value of the bit-field, if requested.
2071  if (Result) {
2072  llvm::Value *ResultVal = MaskedVal;
2073 
2074  // Sign extend the value if needed.
2075  if (Info.IsSigned) {
2076  assert(Info.Size <= Info.StorageSize);
2077  unsigned HighBits = Info.StorageSize - Info.Size;
2078  if (HighBits) {
2079  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2080  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2081  }
2082  }
2083 
2084  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2085  "bf.result.cast");
2086  *Result = EmitFromMemory(ResultVal, Dst.getType());
2087  }
2088 }
2089 
2091  LValue Dst) {
2092  // This access turns into a read/modify/write of the vector. Load the input
2093  // value now.
2095  Dst.isVolatileQualified());
2096  const llvm::Constant *Elts = Dst.getExtVectorElts();
2097 
2098  llvm::Value *SrcVal = Src.getScalarVal();
2099 
2100  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2101  unsigned NumSrcElts = VTy->getNumElements();
2102  unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2103  if (NumDstElts == NumSrcElts) {
2104  // Use shuffle vector is the src and destination are the same number of
2105  // elements and restore the vector mask since it is on the side it will be
2106  // stored.
2107  SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2108  for (unsigned i = 0; i != NumSrcElts; ++i)
2109  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2110 
2111  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2112  Vec = Builder.CreateShuffleVector(SrcVal,
2113  llvm::UndefValue::get(Vec->getType()),
2114  MaskV);
2115  } else if (NumDstElts > NumSrcElts) {
2116  // Extended the source vector to the same length and then shuffle it
2117  // into the destination.
2118  // FIXME: since we're shuffling with undef, can we just use the indices
2119  // into that? This could be simpler.
2121  for (unsigned i = 0; i != NumSrcElts; ++i)
2122  ExtMask.push_back(Builder.getInt32(i));
2123  ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2124  llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2125  llvm::Value *ExtSrcVal =
2126  Builder.CreateShuffleVector(SrcVal,
2127  llvm::UndefValue::get(SrcVal->getType()),
2128  ExtMaskV);
2129  // build identity
2131  for (unsigned i = 0; i != NumDstElts; ++i)
2132  Mask.push_back(Builder.getInt32(i));
2133 
2134  // When the vector size is odd and .odd or .hi is used, the last element
2135  // of the Elts constant array will be one past the size of the vector.
2136  // Ignore the last element here, if it is greater than the mask size.
2137  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2138  NumSrcElts--;
2139 
2140  // modify when what gets shuffled in
2141  for (unsigned i = 0; i != NumSrcElts; ++i)
2142  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2143  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2144  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2145  } else {
2146  // We should never shorten the vector
2147  llvm_unreachable("unexpected shorten vector length");
2148  }
2149  } else {
2150  // If the Src is a scalar (not a vector) it must be updating one element.
2151  unsigned InIdx = getAccessedFieldNo(0, Elts);
2152  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2153  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2154  }
2155 
2157  Dst.isVolatileQualified());
2158 }
2159 
2160 /// Store of global named registers are always calls to intrinsics.
2162  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2163  "Bad type for register variable");
2164  llvm::MDNode *RegName = cast<llvm::MDNode>(
2165  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2166  assert(RegName && "Register LValue is not metadata");
2167 
2168  // We accept integer and pointer types only
2169  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2170  llvm::Type *Ty = OrigTy;
2171  if (OrigTy->isPointerTy())
2172  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2173  llvm::Type *Types[] = { Ty };
2174 
2175  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2176  llvm::Value *Value = Src.getScalarVal();
2177  if (OrigTy->isPointerTy())
2178  Value = Builder.CreatePtrToInt(Value, Ty);
2179  Builder.CreateCall(
2180  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2181 }
2182 
2183 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2184 // generating write-barries API. It is currently a global, ivar,
2185 // or neither.
2186 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2187  LValue &LV,
2188  bool IsMemberAccess=false) {
2189  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2190  return;
2191 
2192  if (isa<ObjCIvarRefExpr>(E)) {
2193  QualType ExpTy = E->getType();
2194  if (IsMemberAccess && ExpTy->isPointerType()) {
2195  // If ivar is a structure pointer, assigning to field of
2196  // this struct follows gcc's behavior and makes it a non-ivar
2197  // writer-barrier conservatively.
2198  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2199  if (ExpTy->isRecordType()) {
2200  LV.setObjCIvar(false);
2201  return;
2202  }
2203  }
2204  LV.setObjCIvar(true);
2205  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2206  LV.setBaseIvarExp(Exp->getBase());
2207  LV.setObjCArray(E->getType()->isArrayType());
2208  return;
2209  }
2210 
2211  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2212  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2213  if (VD->hasGlobalStorage()) {
2214  LV.setGlobalObjCRef(true);
2215  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2216  }
2217  }
2218  LV.setObjCArray(E->getType()->isArrayType());
2219  return;
2220  }
2221 
2222  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2223  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2224  return;
2225  }
2226 
2227  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2228  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2229  if (LV.isObjCIvar()) {
2230  // If cast is to a structure pointer, follow gcc's behavior and make it
2231  // a non-ivar write-barrier.
2232  QualType ExpTy = E->getType();
2233  if (ExpTy->isPointerType())
2234  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2235  if (ExpTy->isRecordType())
2236  LV.setObjCIvar(false);
2237  }
2238  return;
2239  }
2240 
2241  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2242  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2243  return;
2244  }
2245 
2246  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2247  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2248  return;
2249  }
2250 
2251  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2252  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2253  return;
2254  }
2255 
2256  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2257  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2258  return;
2259  }
2260 
2261  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2262  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2263  if (LV.isObjCIvar() && !LV.isObjCArray())
2264  // Using array syntax to assigning to what an ivar points to is not
2265  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2266  LV.setObjCIvar(false);
2267  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2268  // Using array syntax to assigning to what global points to is not
2269  // same as assigning to the global itself. {id *G;} G[i] = 0;
2270  LV.setGlobalObjCRef(false);
2271  return;
2272  }
2273 
2274  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2275  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2276  // We don't know if member is an 'ivar', but this flag is looked at
2277  // only in the context of LV.isObjCIvar().
2278  LV.setObjCArray(E->getType()->isArrayType());
2279  return;
2280  }
2281 }
2282 
2283 static llvm::Value *
2285  llvm::Value *V, llvm::Type *IRType,
2286  StringRef Name = StringRef()) {
2287  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2288  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2289 }
2290 
2292  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2293  llvm::Type *RealVarTy, SourceLocation Loc) {
2294  Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2295  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2296  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2297 }
2298 
2300  const VarDecl *VD, QualType T) {
2302  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2303  // Return an invalid address if variable is MT_To and unified
2304  // memory is not enabled. For all other cases: MT_Link and
2305  // MT_To with unified memory, return a valid address.
2306  if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2307  !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2308  return Address::invalid();
2309  assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2310  (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2311  CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2312  "Expected link clause OR to clause with unified memory enabled.");
2313  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2314  Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2315  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2316 }
2317 
2318 Address
2320  LValueBaseInfo *PointeeBaseInfo,
2321  TBAAAccessInfo *PointeeTBAAInfo) {
2322  llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2323  RefLVal.isVolatile());
2324  CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2325 
2327  PointeeBaseInfo, PointeeTBAAInfo,
2328  /* forPointeeType= */ true);
2329  return Address(Load, Align);
2330 }
2331 
2333  LValueBaseInfo PointeeBaseInfo;
2334  TBAAAccessInfo PointeeTBAAInfo;
2335  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2336  &PointeeTBAAInfo);
2337  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2338  PointeeBaseInfo, PointeeTBAAInfo);
2339 }
2340 
2342  const PointerType *PtrTy,
2343  LValueBaseInfo *BaseInfo,
2344  TBAAAccessInfo *TBAAInfo) {
2345  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2346  return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2347  BaseInfo, TBAAInfo,
2348  /*forPointeeType=*/true));
2349 }
2350 
2352  const PointerType *PtrTy) {
2353  LValueBaseInfo BaseInfo;
2354  TBAAAccessInfo TBAAInfo;
2355  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2356  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2357 }
2358 
2360  const Expr *E, const VarDecl *VD) {
2361  QualType T = E->getType();
2362 
2363  // If it's thread_local, emit a call to its wrapper function instead.
2364  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2366  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2367  // Check if the variable is marked as declare target with link clause in
2368  // device codegen.
2369  if (CGF.getLangOpts().OpenMPIsDevice) {
2370  Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2371  if (Addr.isValid())
2372  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2373  }
2374 
2375  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2376  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2377  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2378  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2379  Address Addr(V, Alignment);
2380  // Emit reference to the private copy of the variable if it is an OpenMP
2381  // threadprivate variable.
2382  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2383  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2384  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2385  E->getExprLoc());
2386  }
2387  LValue LV = VD->getType()->isReferenceType() ?
2388  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2390  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2391  setObjCGCLValueClass(CGF.getContext(), E, LV);
2392  return LV;
2393 }
2394 
2396  const FunctionDecl *FD) {
2397  if (FD->hasAttr<WeakRefAttr>()) {
2398  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2399  return aliasee.getPointer();
2400  }
2401 
2402  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2403  if (!FD->hasPrototype()) {
2404  if (const FunctionProtoType *Proto =
2405  FD->getType()->getAs<FunctionProtoType>()) {
2406  // Ugly case: for a K&R-style definition, the type of the definition
2407  // isn't the same as the type of a use. Correct for this with a
2408  // bitcast.
2409  QualType NoProtoType =
2410  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2411  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2412  V = llvm::ConstantExpr::getBitCast(V,
2413  CGM.getTypes().ConvertType(NoProtoType));
2414  }
2415  }
2416  return V;
2417 }
2418 
2420  const Expr *E, const FunctionDecl *FD) {
2421  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2422  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2423  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2425 }
2426 
2428  llvm::Value *ThisValue) {
2430  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2431  return CGF.EmitLValueForField(LV, FD);
2432 }
2433 
2434 /// Named Registers are named metadata pointing to the register name
2435 /// which will be read from/written to as an argument to the intrinsic
2436 /// @llvm.read/write_register.
2437 /// So far, only the name is being passed down, but other options such as
2438 /// register type, allocation type or even optimization options could be
2439 /// passed down via the metadata node.
2441  SmallString<64> Name("llvm.named.register.");
2442  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2443  assert(Asm->getLabel().size() < 64-Name.size() &&
2444  "Register name too big");
2445  Name.append(Asm->getLabel());
2446  llvm::NamedMDNode *M =
2447  CGM.getModule().getOrInsertNamedMetadata(Name);
2448  if (M->getNumOperands() == 0) {
2449  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2450  Asm->getLabel());
2451  llvm::Metadata *Ops[] = {Str};
2452  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2453  }
2454 
2455  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2456 
2457  llvm::Value *Ptr =
2458  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2459  return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2460 }
2461 
2462 /// Determine whether we can emit a reference to \p VD from the current
2463 /// context, despite not necessarily having seen an odr-use of the variable in
2464 /// this context.
2466  const DeclRefExpr *E,
2467  const VarDecl *VD,
2468  bool IsConstant) {
2469  // For a variable declared in an enclosing scope, do not emit a spurious
2470  // reference even if we have a capture, as that will emit an unwarranted
2471  // reference to our capture state, and will likely generate worse code than
2472  // emitting a local copy.
2474  return false;
2475 
2476  // For a local declaration declared in this function, we can always reference
2477  // it even if we don't have an odr-use.
2478  if (VD->hasLocalStorage()) {
2479  return VD->getDeclContext() ==
2480  dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2481  }
2482 
2483  // For a global declaration, we can emit a reference to it if we know
2484  // for sure that we are able to emit a definition of it.
2485  VD = VD->getDefinition(CGF.getContext());
2486  if (!VD)
2487  return false;
2488 
2489  // Don't emit a spurious reference if it might be to a variable that only
2490  // exists on a different device / target.
2491  // FIXME: This is unnecessarily broad. Check whether this would actually be a
2492  // cross-target reference.
2493  if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2494  CGF.getLangOpts().OpenCL) {
2495  return false;
2496  }
2497 
2498  // We can emit a spurious reference only if the linkage implies that we'll
2499  // be emitting a non-interposable symbol that will be retained until link
2500  // time.
2501  switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2503  case llvm::GlobalValue::LinkOnceODRLinkage:
2504  case llvm::GlobalValue::WeakODRLinkage:
2506  case llvm::GlobalValue::PrivateLinkage:
2507  return true;
2508  default:
2509  return false;
2510  }
2511 }
2512 
2514  const NamedDecl *ND = E->getDecl();
2515  QualType T = E->getType();
2516 
2517  assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2518  "should not emit an unevaluated operand");
2519 
2520  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2521  // Global Named registers access via intrinsics only
2522  if (VD->getStorageClass() == SC_Register &&
2523  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2524  return EmitGlobalNamedRegister(VD, CGM);
2525 
2526  // If this DeclRefExpr does not constitute an odr-use of the variable,
2527  // we're not permitted to emit a reference to it in general, and it might
2528  // not be captured if capture would be necessary for a use. Emit the
2529  // constant value directly instead.
2530  if (E->isNonOdrUse() == NOUR_Constant &&
2531  (VD->getType()->isReferenceType() ||
2532  !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2533  VD->getAnyInitializer(VD);
2534  llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2535  E->getLocation(), *VD->evaluateValue(), VD->getType());
2536  assert(Val && "failed to emit constant expression");
2537 
2538  Address Addr = Address::invalid();
2539  if (!VD->getType()->isReferenceType()) {
2540  // Spill the constant value to a global.
2541  Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2542  getContext().getDeclAlign(VD));
2543  } else {
2544  // Should we be using the alignment of the constant pointer we emitted?
2545  CharUnits Alignment =
2547  /* BaseInfo= */ nullptr,
2548  /* TBAAInfo= */ nullptr,
2549  /* forPointeeType= */ true);
2550  Addr = Address(Val, Alignment);
2551  }
2552  return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2553  }
2554 
2555  // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2556 
2557  // Check for captured variables.
2559  VD = VD->getCanonicalDecl();
2560  if (auto *FD = LambdaCaptureFields.lookup(VD))
2561  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2562  else if (CapturedStmtInfo) {
2563  auto I = LocalDeclMap.find(VD);
2564  if (I != LocalDeclMap.end()) {
2565  if (VD->getType()->isReferenceType())
2566  return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2568  return MakeAddrLValue(I->second, T);
2569  }
2570  LValue CapLVal =
2573  return MakeAddrLValue(
2574  Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2576  CapLVal.getTBAAInfo());
2577  }
2578 
2579  assert(isa<BlockDecl>(CurCodeDecl));
2580  Address addr = GetAddrOfBlockDecl(VD);
2581  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2582  }
2583  }
2584 
2585  // FIXME: We should be able to assert this for FunctionDecls as well!
2586  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2587  // those with a valid source location.
2588  assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2589  !E->getLocation().isValid()) &&
2590  "Should not use decl without marking it used!");
2591 
2592  if (ND->hasAttr<WeakRefAttr>()) {
2593  const auto *VD = cast<ValueDecl>(ND);
2594  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2595  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2596  }
2597 
2598  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2599  // Check if this is a global variable.
2600  if (VD->hasLinkage() || VD->isStaticDataMember())
2601  return EmitGlobalVarDeclLValue(*this, E, VD);
2602 
2603  Address addr = Address::invalid();
2604 
2605  // The variable should generally be present in the local decl map.
2606  auto iter = LocalDeclMap.find(VD);
2607  if (iter != LocalDeclMap.end()) {
2608  addr = iter->second;
2609 
2610  // Otherwise, it might be static local we haven't emitted yet for
2611  // some reason; most likely, because it's in an outer function.
2612  } else if (VD->isStaticLocal()) {
2614  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false)),
2615  getContext().getDeclAlign(VD));
2616 
2617  // No other cases for now.
2618  } else {
2619  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2620  }
2621 
2622 
2623  // Check for OpenMP threadprivate variables.
2624  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2625  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2627  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2628  E->getExprLoc());
2629  }
2630 
2631  // Drill into block byref variables.
2632  bool isBlockByref = VD->isEscapingByref();
2633  if (isBlockByref) {
2634  addr = emitBlockByrefAddress(addr, VD);
2635  }
2636 
2637  // Drill into reference types.
2638  LValue LV = VD->getType()->isReferenceType() ?
2641 
2642  bool isLocalStorage = VD->hasLocalStorage();
2643 
2644  bool NonGCable = isLocalStorage &&
2645  !VD->getType()->isReferenceType() &&
2646  !isBlockByref;
2647  if (NonGCable) {
2648  LV.getQuals().removeObjCGCAttr();
2649  LV.setNonGC(true);
2650  }
2651 
2652  bool isImpreciseLifetime =
2653  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2654  if (isImpreciseLifetime)
2656  setObjCGCLValueClass(getContext(), E, LV);
2657  return LV;
2658  }
2659 
2660  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2661  return EmitFunctionDeclLValue(*this, E, FD);
2662 
2663  // FIXME: While we're emitting a binding from an enclosing scope, all other
2664  // DeclRefExprs we see should be implicitly treated as if they also refer to
2665  // an enclosing scope.
2666  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2667  return EmitLValue(BD->getBinding());
2668 
2669  llvm_unreachable("Unhandled DeclRefExpr");
2670 }
2671 
2673  // __extension__ doesn't affect lvalue-ness.
2674  if (E->getOpcode() == UO_Extension)
2675  return EmitLValue(E->getSubExpr());
2676 
2678  switch (E->getOpcode()) {
2679  default: llvm_unreachable("Unknown unary operator lvalue!");
2680  case UO_Deref: {
2681  QualType T = E->getSubExpr()->getType()->getPointeeType();
2682  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2683 
2684  LValueBaseInfo BaseInfo;
2685  TBAAAccessInfo TBAAInfo;
2686  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2687  &TBAAInfo);
2688  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2689  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2690 
2691  // We should not generate __weak write barrier on indirect reference
2692  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2693  // But, we continue to generate __strong write barrier on indirect write
2694  // into a pointer to object.
2695  if (getLangOpts().ObjC &&
2696  getLangOpts().getGC() != LangOptions::NonGC &&
2697  LV.isObjCWeak())
2698  LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2699  return LV;
2700  }
2701  case UO_Real:
2702  case UO_Imag: {
2703  LValue LV = EmitLValue(E->getSubExpr());
2704  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2705 
2706  // __real is valid on scalars. This is a faster way of testing that.
2707  // __imag can only produce an rvalue on scalars.
2708  if (E->getOpcode() == UO_Real &&
2709  !LV.getAddress().getElementType()->isStructTy()) {
2710  assert(E->getSubExpr()->getType()->isArithmeticType());
2711  return LV;
2712  }
2713 
2714  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2715 
2716  Address Component =
2717  (E->getOpcode() == UO_Real
2720  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2721  CGM.getTBAAInfoForSubobject(LV, T));
2722  ElemLV.getQuals().addQualifiers(LV.getQuals());
2723  return ElemLV;
2724  }
2725  case UO_PreInc:
2726  case UO_PreDec: {
2727  LValue LV = EmitLValue(E->getSubExpr());
2728  bool isInc = E->getOpcode() == UO_PreInc;
2729 
2730  if (E->getType()->isAnyComplexType())
2731  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2732  else
2733  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2734  return LV;
2735  }
2736  }
2737 }
2738 
2742 }
2743 
2747 }
2748 
2750  auto SL = E->getFunctionName();
2751  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2752  StringRef FnName = CurFn->getName();
2753  if (FnName.startswith("\01"))
2754  FnName = FnName.substr(1);
2755  StringRef NameItems[] = {
2757  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2758  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2759  std::string Name = SL->getString();
2760  if (!Name.empty()) {
2761  unsigned Discriminator =
2762  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2763  if (Discriminator)
2764  Name += "_" + Twine(Discriminator + 1).str();
2765  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2766  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2767  } else {
2768  auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2769  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2770  }
2771  }
2772  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2773  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2774 }
2775 
2776 /// Emit a type description suitable for use by a runtime sanitizer library. The
2777 /// format of a type descriptor is
2778 ///
2779 /// \code
2780 /// { i16 TypeKind, i16 TypeInfo }
2781 /// \endcode
2782 ///
2783 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2784 /// integer, 1 for a floating point value, and -1 for anything else.
2786  // Only emit each type's descriptor once.
2787  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2788  return C;
2789 
2790  uint16_t TypeKind = -1;
2791  uint16_t TypeInfo = 0;
2792 
2793  if (T->isIntegerType()) {
2794  TypeKind = 0;
2795  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2796  (T->isSignedIntegerType() ? 1 : 0);
2797  } else if (T->isFloatingType()) {
2798  TypeKind = 1;
2799  TypeInfo = getContext().getTypeSize(T);
2800  }
2801 
2802  // Format the type name as if for a diagnostic, including quotes and
2803  // optionally an 'aka'.
2804  SmallString<32> Buffer;
2806  (intptr_t)T.getAsOpaquePtr(),
2807  StringRef(), StringRef(), None, Buffer,
2808  None);
2809 
2810  llvm::Constant *Components[] = {
2811  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2812  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2813  };
2814  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2815 
2816  auto *GV = new llvm::GlobalVariable(
2817  CGM.getModule(), Descriptor->getType(),
2818  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2819  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2821 
2822  // Remember the descriptor for this type.
2823  CGM.setTypeDescriptorInMap(T, GV);
2824 
2825  return GV;
2826 }
2827 
2829  llvm::Type *TargetTy = IntPtrTy;
2830 
2831  if (V->getType() == TargetTy)
2832  return V;
2833 
2834  // Floating-point types which fit into intptr_t are bitcast to integers
2835  // and then passed directly (after zero-extension, if necessary).
2836  if (V->getType()->isFloatingPointTy()) {
2837  unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2838  if (Bits <= TargetTy->getIntegerBitWidth())
2839  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2840  Bits));
2841  }
2842 
2843  // Integers which fit in intptr_t are zero-extended and passed directly.
2844  if (V->getType()->isIntegerTy() &&
2845  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2846  return Builder.CreateZExt(V, TargetTy);
2847 
2848  // Pointers are passed directly, everything else is passed by address.
2849  if (!V->getType()->isPointerTy()) {
2850  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2851  Builder.CreateStore(V, Ptr);
2852  V = Ptr.getPointer();
2853  }
2854  return Builder.CreatePtrToInt(V, TargetTy);
2855 }
2856 
2857 /// Emit a representation of a SourceLocation for passing to a handler
2858 /// in a sanitizer runtime library. The format for this data is:
2859 /// \code
2860 /// struct SourceLocation {
2861 /// const char *Filename;
2862 /// int32_t Line, Column;
2863 /// };
2864 /// \endcode
2865 /// For an invalid SourceLocation, the Filename pointer is null.
2867  llvm::Constant *Filename;
2868  int Line, Column;
2869 
2871  if (PLoc.isValid()) {
2872  StringRef FilenameString = PLoc.getFilename();
2873 
2874  int PathComponentsToStrip =
2875  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2876  if (PathComponentsToStrip < 0) {
2877  assert(PathComponentsToStrip != INT_MIN);
2878  int PathComponentsToKeep = -PathComponentsToStrip;
2879  auto I = llvm::sys::path::rbegin(FilenameString);
2880  auto E = llvm::sys::path::rend(FilenameString);
2881  while (I != E && --PathComponentsToKeep)
2882  ++I;
2883 
2884  FilenameString = FilenameString.substr(I - E);
2885  } else if (PathComponentsToStrip > 0) {
2886  auto I = llvm::sys::path::begin(FilenameString);
2887  auto E = llvm::sys::path::end(FilenameString);
2888  while (I != E && PathComponentsToStrip--)
2889  ++I;
2890 
2891  if (I != E)
2892  FilenameString =
2893  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2894  else
2895  FilenameString = llvm::sys::path::filename(FilenameString);
2896  }
2897 
2898  auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2900  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2901  Filename = FilenameGV.getPointer();
2902  Line = PLoc.getLine();
2903  Column = PLoc.getColumn();
2904  } else {
2905  Filename = llvm::Constant::getNullValue(Int8PtrTy);
2906  Line = Column = 0;
2907  }
2908 
2909  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2910  Builder.getInt32(Column)};
2911 
2912  return llvm::ConstantStruct::getAnon(Data);
2913 }
2914 
2915 namespace {
2916 /// Specify under what conditions this check can be recovered
2918  /// Always terminate program execution if this check fails.
2919  Unrecoverable,
2920  /// Check supports recovering, runtime has both fatal (noreturn) and
2921  /// non-fatal handlers for this check.
2922  Recoverable,
2923  /// Runtime conditionally aborts, always need to support recovery.
2925 };
2926 }
2927 
2929  assert(Kind.countPopulation() == 1);
2930  if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
2932  else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
2934  else
2935  return CheckRecoverableKind::Recoverable;
2936 }
2937 
2938 namespace {
2939 struct SanitizerHandlerInfo {
2940  char const *const Name;
2941  unsigned Version;
2942 };
2943 }
2944 
2945 const SanitizerHandlerInfo SanitizerHandlers[] = {
2946 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2948 #undef SANITIZER_CHECK
2949 };
2950 
2952  llvm::FunctionType *FnType,
2953  ArrayRef<llvm::Value *> FnArgs,
2954  SanitizerHandler CheckHandler,
2955  CheckRecoverableKind RecoverKind, bool IsFatal,
2956  llvm::BasicBlock *ContBB) {
2957  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2959  if (!CGF.Builder.getCurrentDebugLocation()) {
2960  // Ensure that the call has at least an artificial debug location.
2961  DL.emplace(CGF, SourceLocation());
2962  }
2963  bool NeedsAbortSuffix =
2964  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2965  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2966  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2967  const StringRef CheckName = CheckInfo.Name;
2968  std::string FnName = "__ubsan_handle_" + CheckName.str();
2969  if (CheckInfo.Version && !MinimalRuntime)
2970  FnName += "_v" + llvm::utostr(CheckInfo.Version);
2971  if (MinimalRuntime)
2972  FnName += "_minimal";
2973  if (NeedsAbortSuffix)
2974  FnName += "_abort";
2975  bool MayReturn =
2976  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2977 
2978  llvm::AttrBuilder B;
2979  if (!MayReturn) {
2980  B.addAttribute(llvm::Attribute::NoReturn)
2981  .addAttribute(llvm::Attribute::NoUnwind);
2982  }
2983  B.addAttribute(llvm::Attribute::UWTable);
2984 
2985  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
2986  FnType, FnName,
2987  llvm::AttributeList::get(CGF.getLLVMContext(),
2988  llvm::AttributeList::FunctionIndex, B),
2989  /*Local=*/true);
2990  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2991  if (!MayReturn) {
2992  HandlerCall->setDoesNotReturn();
2993  CGF.Builder.CreateUnreachable();
2994  } else {
2995  CGF.Builder.CreateBr(ContBB);
2996  }
2997 }
2998 
3000  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3001  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3002  ArrayRef<llvm::Value *> DynamicArgs) {
3003  assert(IsSanitizerScope);
3004  assert(Checked.size() > 0);
3005  assert(CheckHandler >= 0 &&
3006  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3007  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3008 
3009  llvm::Value *FatalCond = nullptr;
3010  llvm::Value *RecoverableCond = nullptr;
3011  llvm::Value *TrapCond = nullptr;
3012  for (int i = 0, n = Checked.size(); i < n; ++i) {
3013  llvm::Value *Check = Checked[i].first;
3014  // -fsanitize-trap= overrides -fsanitize-recover=.
3015  llvm::Value *&Cond =
3016  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3017  ? TrapCond
3018  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3019  ? RecoverableCond
3020  : FatalCond;
3021  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3022  }
3023 
3024  if (TrapCond)
3025  EmitTrapCheck(TrapCond);
3026  if (!FatalCond && !RecoverableCond)
3027  return;
3028 
3029  llvm::Value *JointCond;
3030  if (FatalCond && RecoverableCond)
3031  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3032  else
3033  JointCond = FatalCond ? FatalCond : RecoverableCond;
3034  assert(JointCond);
3035 
3036  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3037  assert(SanOpts.has(Checked[0].second));
3038 #ifndef NDEBUG
3039  for (int i = 1, n = Checked.size(); i < n; ++i) {
3040  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3041  "All recoverable kinds in a single check must be same!");
3042  assert(SanOpts.has(Checked[i].second));
3043  }
3044 #endif
3045 
3046  llvm::BasicBlock *Cont = createBasicBlock("cont");
3047  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3048  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3049  // Give hint that we very much don't expect to execute the handler
3050  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3051  llvm::MDBuilder MDHelper(getLLVMContext());
3052  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3053  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3054  EmitBlock(Handlers);
3055 
3056  // Handler functions take an i8* pointing to the (handler-specific) static
3057  // information block, followed by a sequence of intptr_t arguments
3058  // representing operand values.
3061  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3062  Args.reserve(DynamicArgs.size() + 1);
3063  ArgTypes.reserve(DynamicArgs.size() + 1);
3064 
3065  // Emit handler arguments and create handler function type.
3066  if (!StaticArgs.empty()) {
3067  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3068  auto *InfoPtr =
3069  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3070  llvm::GlobalVariable::PrivateLinkage, Info);
3071  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3073  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3074  ArgTypes.push_back(Int8PtrTy);
3075  }
3076 
3077  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3078  Args.push_back(EmitCheckValue(DynamicArgs[i]));
3079  ArgTypes.push_back(IntPtrTy);
3080  }
3081  }
3082 
3083  llvm::FunctionType *FnType =
3084  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3085 
3086  if (!FatalCond || !RecoverableCond) {
3087  // Simple case: we need to generate a single handler call, either
3088  // fatal, or non-fatal.
3089  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3090  (FatalCond != nullptr), Cont);
3091  } else {
3092  // Emit two handler calls: first one for set of unrecoverable checks,
3093  // another one for recoverable.
3094  llvm::BasicBlock *NonFatalHandlerBB =
3095  createBasicBlock("non_fatal." + CheckName);
3096  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3097  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3098  EmitBlock(FatalHandlerBB);
3099  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3100  NonFatalHandlerBB);
3101  EmitBlock(NonFatalHandlerBB);
3102  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3103  Cont);
3104  }
3105 
3106  EmitBlock(Cont);
3107 }
3108 
3110  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3111  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3112  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3113 
3114  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3115  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3116 
3117  llvm::MDBuilder MDHelper(getLLVMContext());
3118  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3119  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3120 
3121  EmitBlock(CheckBB);
3122 
3123  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3124 
3125  llvm::CallInst *CheckCall;
3126  llvm::FunctionCallee SlowPathFn;
3127  if (WithDiag) {
3128  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3129  auto *InfoPtr =
3130  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3131  llvm::GlobalVariable::PrivateLinkage, Info);
3132  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3134 
3135  SlowPathFn = CGM.getModule().getOrInsertFunction(
3136  "__cfi_slowpath_diag",
3137  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3138  false));
3139  CheckCall = Builder.CreateCall(
3140  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3141  } else {
3142  SlowPathFn = CGM.getModule().getOrInsertFunction(
3143  "__cfi_slowpath",
3144  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3145  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3146  }
3147 
3148  CGM.setDSOLocal(
3149  cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3150  CheckCall->setDoesNotThrow();
3151 
3152  EmitBlock(Cont);
3153 }
3154 
3155 // Emit a stub for __cfi_check function so that the linker knows about this
3156 // symbol in LTO mode.
3158  llvm::Module *M = &CGM.getModule();
3159  auto &Ctx = M->getContext();
3160  llvm::Function *F = llvm::Function::Create(
3161  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3162  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3163  CGM.setDSOLocal(F);
3164  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3165  // FIXME: consider emitting an intrinsic call like
3166  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3167  // which can be lowered in CrossDSOCFI pass to the actual contents of
3168  // __cfi_check. This would allow inlining of __cfi_check calls.
3170  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3171  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3172 }
3173 
3174 // This function is basically a switch over the CFI failure kind, which is
3175 // extracted from CFICheckFailData (1st function argument). Each case is either
3176 // llvm.trap or a call to one of the two runtime handlers, based on
3177 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3178 // failure kind) traps, but this should really never happen. CFICheckFailData
3179 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3180 // check kind; in this case __cfi_check_fail traps as well.
3182  SanitizerScope SanScope(this);
3183  FunctionArgList Args;
3188  Args.push_back(&ArgData);
3189  Args.push_back(&ArgAddr);
3190 
3191  const CGFunctionInfo &FI =
3193 
3194  llvm::Function *F = llvm::Function::Create(
3195  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3196  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3197  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3198 
3199  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3200  SourceLocation());
3201 
3202  // This function should not be affected by blacklist. This function does
3203  // not have a source location, but "src:*" would still apply. Revert any
3204  // changes to SanOpts made in StartFunction.
3206 
3207  llvm::Value *Data =
3208  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3209  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3210  llvm::Value *Addr =
3211  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3212  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3213 
3214  // Data == nullptr means the calling module has trap behaviour for this check.
3215  llvm::Value *DataIsNotNullPtr =
3216  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3217  EmitTrapCheck(DataIsNotNullPtr);
3218 
3219  llvm::StructType *SourceLocationTy =
3220  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3221  llvm::StructType *CfiCheckFailDataTy =
3222  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3223 
3224  llvm::Value *V = Builder.CreateConstGEP2_32(
3225  CfiCheckFailDataTy,
3226  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3227  0);
3228  Address CheckKindAddr(V, getIntAlign());
3229  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3230 
3231  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3232  CGM.getLLVMContext(),
3233  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3234  llvm::Value *ValidVtable = Builder.CreateZExt(
3235  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3236  {Addr, AllVtables}),
3237  IntPtrTy);
3238 
3239  const std::pair<int, SanitizerMask> CheckKinds[] = {
3240  {CFITCK_VCall, SanitizerKind::CFIVCall},
3241  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3242  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3243  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3244  {CFITCK_ICall, SanitizerKind::CFIICall}};
3245 
3247  for (auto CheckKindMaskPair : CheckKinds) {
3248  int Kind = CheckKindMaskPair.first;
3249  SanitizerMask Mask = CheckKindMaskPair.second;
3250  llvm::Value *Cond =
3251  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3252  if (CGM.getLangOpts().Sanitize.has(Mask))
3253  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3254  {Data, Addr, ValidVtable});
3255  else
3256  EmitTrapCheck(Cond);
3257  }
3258 
3259  FinishFunction();
3260  // The only reference to this function will be created during LTO link.
3261  // Make sure it survives until then.
3262  CGM.addUsedGlobal(F);
3263 }
3264 
3266  if (SanOpts.has(SanitizerKind::Unreachable)) {
3267  SanitizerScope SanScope(this);
3268  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3269  SanitizerKind::Unreachable),
3270  SanitizerHandler::BuiltinUnreachable,
3271  EmitCheckSourceLocation(Loc), None);
3272  }
3273  Builder.CreateUnreachable();
3274 }
3275 
3277  llvm::BasicBlock *Cont = createBasicBlock("cont");
3278 
3279  // If we're optimizing, collapse all calls to trap down to just one per
3280  // function to save on code size.
3281  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3282  TrapBB = createBasicBlock("trap");
3283  Builder.CreateCondBr(Checked, Cont, TrapBB);
3284  EmitBlock(TrapBB);
3285  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3286  TrapCall->setDoesNotReturn();
3287  TrapCall->setDoesNotThrow();
3288  Builder.CreateUnreachable();
3289  } else {
3290  Builder.CreateCondBr(Checked, Cont, TrapBB);
3291  }
3292 
3293  EmitBlock(Cont);
3294 }
3295 
3297  llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3298 
3299  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3300  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3302  TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3303  }
3304 
3305  return TrapCall;
3306 }
3307 
3309  LValueBaseInfo *BaseInfo,
3310  TBAAAccessInfo *TBAAInfo) {
3311  assert(E->getType()->isArrayType() &&
3312  "Array to pointer decay must have array source type!");
3313 
3314  // Expressions of array type can't be bitfields or vector elements.
3315  LValue LV = EmitLValue(E);
3316  Address Addr = LV.getAddress();
3317 
3318  // If the array type was an incomplete type, we need to make sure
3319  // the decay ends up being the right type.
3320  llvm::Type *NewTy = ConvertType(E->getType());
3321  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3322 
3323  // Note that VLA pointers are always decayed, so we don't need to do
3324  // anything here.
3325  if (!E->getType()->isVariableArrayType()) {
3326  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3327  "Expected pointer to array");
3328  Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3329  }
3330 
3331  // The result of this decay conversion points to an array element within the
3332  // base lvalue. However, since TBAA currently does not support representing
3333  // accesses to elements of member arrays, we conservatively represent accesses
3334  // to the pointee object as if it had no any base lvalue specified.
3335  // TODO: Support TBAA for member arrays.
3337  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3338  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3339 
3340  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3341 }
3342 
3343 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3344 /// array to pointer, return the array subexpression.
3345 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3346  // If this isn't just an array->pointer decay, bail out.
3347  const auto *CE = dyn_cast<CastExpr>(E);
3348  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3349  return nullptr;
3350 
3351  // If this is a decay from variable width array, bail out.
3352  const Expr *SubExpr = CE->getSubExpr();
3353  if (SubExpr->getType()->isVariableArrayType())
3354  return nullptr;
3355 
3356  return SubExpr;
3357 }
3358 
3360  llvm::Value *ptr,
3361  ArrayRef<llvm::Value*> indices,
3362  bool inbounds,
3363  bool signedIndices,
3364  SourceLocation loc,
3365  const llvm::Twine &name = "arrayidx") {
3366  if (inbounds) {
3367  return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3369  name);
3370  } else {
3371  return CGF.Builder.CreateGEP(ptr, indices, name);
3372  }
3373 }
3374 
3376  llvm::Value *idx,
3377  CharUnits eltSize) {
3378  // If we have a constant index, we can use the exact offset of the
3379  // element we're accessing.
3380  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3381  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3382  return arrayAlign.alignmentAtOffset(offset);
3383 
3384  // Otherwise, use the worst-case alignment for any element.
3385  } else {
3386  return arrayAlign.alignmentOfArrayElement(eltSize);
3387  }
3388 }
3389 
3391  const VariableArrayType *vla) {
3392  QualType eltType;
3393  do {
3394  eltType = vla->getElementType();
3395  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3396  return eltType;
3397 }
3398 
3400  ArrayRef<llvm::Value *> indices,
3401  QualType eltType, bool inbounds,
3402  bool signedIndices, SourceLocation loc,
3403  const llvm::Twine &name = "arrayidx") {
3404  // All the indices except that last must be zero.
3405 #ifndef NDEBUG
3406  for (auto idx : indices.drop_back())
3407  assert(isa<llvm::ConstantInt>(idx) &&
3408  cast<llvm::ConstantInt>(idx)->isZero());
3409 #endif
3410 
3411  // Determine the element size of the statically-sized base. This is
3412  // the thing that the indices are expressed in terms of.
3413  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3414  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3415  }
3416 
3417  // We can use that to compute the best alignment of the element.
3418  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3419  CharUnits eltAlign =
3420  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3421 
3422  llvm::Value *eltPtr;
3423  auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3424  if (!CGF.IsInPreservedAIRegion || !LastIndex) {
3425  eltPtr = emitArraySubscriptGEP(
3426  CGF, addr.getPointer(), indices, inbounds, signedIndices,
3427  loc, name);
3428  } else {
3429  // Remember the original array subscript for bpf target
3430  unsigned idx = LastIndex->getZExtValue();
3431  eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getPointer(),
3432  indices.size() - 1,
3433  idx);
3434  }
3435 
3436  return Address(eltPtr, eltAlign);
3437 }
3438 
3440  bool Accessed) {
3441  // The index must always be an integer, which is not an aggregate. Emit it
3442  // in lexical order (this complexity is, sadly, required by C++17).
3443  llvm::Value *IdxPre =
3444  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3445  bool SignedIndices = false;
3446  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3447  auto *Idx = IdxPre;
3448  if (E->getLHS() != E->getIdx()) {
3449  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3450  Idx = EmitScalarExpr(E->getIdx());
3451  }
3452 
3453  QualType IdxTy = E->getIdx()->getType();
3454  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3455  SignedIndices |= IdxSigned;
3456 
3457  if (SanOpts.has(SanitizerKind::ArrayBounds))
3458  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3459 
3460  // Extend or truncate the index type to 32 or 64-bits.
3461  if (Promote && Idx->getType() != IntPtrTy)
3462  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3463 
3464  return Idx;
3465  };
3466  IdxPre = nullptr;
3467 
3468  // If the base is a vector type, then we are forming a vector element lvalue
3469  // with this subscript.
3470  if (E->getBase()->getType()->isVectorType() &&
3471  !isa<ExtVectorElementExpr>(E->getBase())) {
3472  // Emit the vector as an lvalue to get its address.
3473  LValue LHS = EmitLValue(E->getBase());
3474  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3475  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3476  return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3477  LHS.getBaseInfo(), TBAAAccessInfo());
3478  }
3479 
3480  // All the other cases basically behave like simple offsetting.
3481 
3482  // Handle the extvector case we ignored above.
3483  if (isa<ExtVectorElementExpr>(E->getBase())) {
3484  LValue LV = EmitLValue(E->getBase());
3485  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3487 
3488  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3489  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3490  SignedIndices, E->getExprLoc());
3491  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3492  CGM.getTBAAInfoForSubobject(LV, EltType));
3493  }
3494 
3495  LValueBaseInfo EltBaseInfo;
3496  TBAAAccessInfo EltTBAAInfo;
3497  Address Addr = Address::invalid();
3498  if (const VariableArrayType *vla =
3499  getContext().getAsVariableArrayType(E->getType())) {
3500  // The base must be a pointer, which is not an aggregate. Emit
3501  // it. It needs to be emitted first in case it's what captures
3502  // the VLA bounds.
3503  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3504  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3505 
3506  // The element count here is the total number of non-VLA elements.
3507  llvm::Value *numElements = getVLASize(vla).NumElts;
3508 
3509  // Effectively, the multiply by the VLA size is part of the GEP.
3510  // GEP indexes are signed, and scaling an index isn't permitted to
3511  // signed-overflow, so we use the same semantics for our explicit
3512  // multiply. We suppress this if overflow is not undefined behavior.
3513  if (getLangOpts().isSignedOverflowDefined()) {
3514  Idx = Builder.CreateMul(Idx, numElements);
3515  } else {
3516  Idx = Builder.CreateNSWMul(Idx, numElements);
3517  }
3518 
3519  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3521  SignedIndices, E->getExprLoc());
3522 
3523  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3524  // Indexing over an interface, as in "NSString *P; P[4];"
3525 
3526  // Emit the base pointer.
3527  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3528  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3529 
3530  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3531  llvm::Value *InterfaceSizeVal =
3532  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3533 
3534  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3535 
3536  // We don't necessarily build correct LLVM struct types for ObjC
3537  // interfaces, so we can't rely on GEP to do this scaling
3538  // correctly, so we need to cast to i8*. FIXME: is this actually
3539  // true? A lot of other things in the fragile ABI would break...
3540  llvm::Type *OrigBaseTy = Addr.getType();
3541  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3542 
3543  // Do the GEP.
3544  CharUnits EltAlign =
3545  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3546  llvm::Value *EltPtr =
3547  emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3548  SignedIndices, E->getExprLoc());
3549  Addr = Address(EltPtr, EltAlign);
3550 
3551  // Cast back.
3552  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3553  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3554  // If this is A[i] where A is an array, the frontend will have decayed the
3555  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3556  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3557  // "gep x, i" here. Emit one "gep A, 0, i".
3558  assert(Array->getType()->isArrayType() &&
3559  "Array to pointer decay must have array source type!");
3560  LValue ArrayLV;
3561  // For simple multidimensional array indexing, set the 'accessed' flag for
3562  // better bounds-checking of the base expression.
3563  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3564  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3565  else
3566  ArrayLV = EmitLValue(Array);
3567  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3568 
3569  // Propagate the alignment from the array itself to the result.
3570  Addr = emitArraySubscriptGEP(
3571  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3572  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3573  E->getExprLoc());
3574  EltBaseInfo = ArrayLV.getBaseInfo();
3575  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3576  } else {
3577  // The base must be a pointer; emit it with an estimate of its alignment.
3578  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3579  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3580  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3582  SignedIndices, E->getExprLoc());
3583  }
3584 
3585  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3586 
3587  if (getLangOpts().ObjC &&
3588  getLangOpts().getGC() != LangOptions::NonGC) {
3590  setObjCGCLValueClass(getContext(), E, LV);
3591  }
3592  return LV;
3593 }
3594 
3596  LValueBaseInfo &BaseInfo,
3597  TBAAAccessInfo &TBAAInfo,
3598  QualType BaseTy, QualType ElTy,
3599  bool IsLowerBound) {
3600  LValue BaseLVal;
3601  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3602  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3603  if (BaseTy->isArrayType()) {
3604  Address Addr = BaseLVal.getAddress();
3605  BaseInfo = BaseLVal.getBaseInfo();
3606 
3607  // If the array type was an incomplete type, we need to make sure
3608  // the decay ends up being the right type.
3609  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3610  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3611 
3612  // Note that VLA pointers are always decayed, so we don't need to do
3613  // anything here.
3614  if (!BaseTy->isVariableArrayType()) {
3615  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3616  "Expected pointer to array");
3617  Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3618  }
3619 
3620  return CGF.Builder.CreateElementBitCast(Addr,
3621  CGF.ConvertTypeForMem(ElTy));
3622  }
3623  LValueBaseInfo TypeBaseInfo;
3624  TBAAAccessInfo TypeTBAAInfo;
3625  CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3626  &TypeTBAAInfo);
3627  BaseInfo.mergeForCast(TypeBaseInfo);
3628  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3629  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3630  }
3631  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3632 }
3633 
3635  bool IsLowerBound) {
3637  QualType ResultExprTy;
3638  if (auto *AT = getContext().getAsArrayType(BaseTy))
3639  ResultExprTy = AT->getElementType();
3640  else
3641  ResultExprTy = BaseTy->getPointeeType();
3642  llvm::Value *Idx = nullptr;
3643  if (IsLowerBound || E->getColonLoc().isInvalid()) {
3644  // Requesting lower bound or upper bound, but without provided length and
3645  // without ':' symbol for the default length -> length = 1.
3646  // Idx = LowerBound ?: 0;
3647  if (auto *LowerBound = E->getLowerBound()) {
3648  Idx = Builder.CreateIntCast(
3649  EmitScalarExpr(LowerBound), IntPtrTy,
3650  LowerBound->getType()->hasSignedIntegerRepresentation());
3651  } else
3652  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3653  } else {
3654  // Try to emit length or lower bound as constant. If this is possible, 1
3655  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3656  // IR (LB + Len) - 1.
3657  auto &C = CGM.getContext();
3658  auto *Length = E->getLength();
3659  llvm::APSInt ConstLength;
3660  if (Length) {
3661  // Idx = LowerBound + Length - 1;
3662  if (Length->isIntegerConstantExpr(ConstLength, C)) {
3663  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3664  Length = nullptr;
3665  }
3666  auto *LowerBound = E->getLowerBound();
3667  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3668  if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3669  ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3670  LowerBound = nullptr;
3671  }
3672  if (!Length)
3673  --ConstLength;
3674  else if (!LowerBound)
3675  --ConstLowerBound;
3676 
3677  if (Length || LowerBound) {
3678  auto *LowerBoundVal =
3679  LowerBound
3680  ? Builder.CreateIntCast(
3681  EmitScalarExpr(LowerBound), IntPtrTy,
3682  LowerBound->getType()->hasSignedIntegerRepresentation())
3683  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3684  auto *LengthVal =
3685  Length
3686  ? Builder.CreateIntCast(
3687  EmitScalarExpr(Length), IntPtrTy,
3688  Length->getType()->hasSignedIntegerRepresentation())
3689  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3690  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3691  /*HasNUW=*/false,
3692  !getLangOpts().isSignedOverflowDefined());
3693  if (Length && LowerBound) {
3694  Idx = Builder.CreateSub(
3695  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3696  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3697  }
3698  } else
3699  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3700  } else {
3701  // Idx = ArraySize - 1;
3702  QualType ArrayTy = BaseTy->isPointerType()
3703  ? E->getBase()->IgnoreParenImpCasts()->getType()
3704  : BaseTy;
3705  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3706  Length = VAT->getSizeExpr();
3707  if (Length->isIntegerConstantExpr(ConstLength, C))
3708  Length = nullptr;
3709  } else {
3710  auto *CAT = C.getAsConstantArrayType(ArrayTy);
3711  ConstLength = CAT->getSize();
3712  }
3713  if (Length) {
3714  auto *LengthVal = Builder.CreateIntCast(
3715  EmitScalarExpr(Length), IntPtrTy,
3716  Length->getType()->hasSignedIntegerRepresentation());
3717  Idx = Builder.CreateSub(
3718  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3719  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3720  } else {
3721  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3722  --ConstLength;
3723  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3724  }
3725  }
3726  }
3727  assert(Idx);
3728 
3729  Address EltPtr = Address::invalid();
3730  LValueBaseInfo BaseInfo;
3731  TBAAAccessInfo TBAAInfo;
3732  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3733  // The base must be a pointer, which is not an aggregate. Emit
3734  // it. It needs to be emitted first in case it's what captures
3735  // the VLA bounds.
3736  Address Base =
3737  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3738  BaseTy, VLA->getElementType(), IsLowerBound);
3739  // The element count here is the total number of non-VLA elements.
3740  llvm::Value *NumElements = getVLASize(VLA).NumElts;
3741 
3742  // Effectively, the multiply by the VLA size is part of the GEP.
3743  // GEP indexes are signed, and scaling an index isn't permitted to
3744  // signed-overflow, so we use the same semantics for our explicit
3745  // multiply. We suppress this if overflow is not undefined behavior.
3746  if (getLangOpts().isSignedOverflowDefined())
3747  Idx = Builder.CreateMul(Idx, NumElements);
3748  else
3749  Idx = Builder.CreateNSWMul(Idx, NumElements);
3750  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3752  /*signedIndices=*/false, E->getExprLoc());
3753  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3754  // If this is A[i] where A is an array, the frontend will have decayed the
3755  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3756  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3757  // "gep x, i" here. Emit one "gep A, 0, i".
3758  assert(Array->getType()->isArrayType() &&
3759  "Array to pointer decay must have array source type!");
3760  LValue ArrayLV;
3761  // For simple multidimensional array indexing, set the 'accessed' flag for
3762  // better bounds-checking of the base expression.
3763  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3764  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3765  else
3766  ArrayLV = EmitLValue(Array);
3767 
3768  // Propagate the alignment from the array itself to the result.
3769  EltPtr = emitArraySubscriptGEP(
3770  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3771  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3772  /*signedIndices=*/false, E->getExprLoc());
3773  BaseInfo = ArrayLV.getBaseInfo();
3774  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3775  } else {
3776  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3777  TBAAInfo, BaseTy, ResultExprTy,
3778  IsLowerBound);
3779  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3780  !getLangOpts().isSignedOverflowDefined(),
3781  /*signedIndices=*/false, E->getExprLoc());
3782  }
3783 
3784  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3785 }
3786 
3789  // Emit the base vector as an l-value.
3790  LValue Base;
3791 
3792  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3793  if (E->isArrow()) {
3794  // If it is a pointer to a vector, emit the address and form an lvalue with
3795  // it.
3796  LValueBaseInfo BaseInfo;
3797  TBAAAccessInfo TBAAInfo;
3798  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3799  const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3800  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3801  Base.getQuals().removeObjCGCAttr();
3802  } else if (E->getBase()->isGLValue()) {
3803  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3804  // emit the base as an lvalue.
3805  assert(E->getBase()->getType()->isVectorType());
3806  Base = EmitLValue(E->getBase());
3807  } else {
3808  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3809  assert(E->getBase()->getType()->isVectorType() &&
3810  "Result must be a vector");
3811  llvm::Value *Vec = EmitScalarExpr(E->getBase());
3812 
3813  // Store the vector to memory (because LValue wants an address).
3814  Address VecMem = CreateMemTemp(E->getBase()->getType());
3815  Builder.CreateStore(Vec, VecMem);
3816  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3818  }
3819 
3820  QualType type =
3822 
3823  // Encode the element access list into a vector of unsigned indices.
3824  SmallVector<uint32_t, 4> Indices;
3825  E->getEncodedElementAccess(Indices);
3826 
3827  if (Base.isSimple()) {
3828  llvm::Constant *CV =
3829  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3830  return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3831  Base.getBaseInfo(), TBAAAccessInfo());
3832  }
3833  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3834 
3835  llvm::Constant *BaseElts = Base.getExtVectorElts();
3837 
3838  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3839  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3840  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3842  Base.getBaseInfo(), TBAAAccessInfo());
3843 }
3844 
3846  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3847  EmitIgnoredExpr(E->getBase());
3848  return EmitDeclRefLValue(DRE);
3849  }
3850 
3851  Expr *BaseExpr = E->getBase();
3852  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3853  LValue BaseLV;
3854  if (E->isArrow()) {
3855  LValueBaseInfo BaseInfo;
3856  TBAAAccessInfo TBAAInfo;
3857  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3858  QualType PtrTy = BaseExpr->getType()->getPointeeType();
3859  SanitizerSet SkippedChecks;
3860  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3861  if (IsBaseCXXThis)
3862  SkippedChecks.set(SanitizerKind::Alignment, true);
3863  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3864  SkippedChecks.set(SanitizerKind::Null, true);
3865  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3866  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3867  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3868  } else
3869  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3870 
3871  NamedDecl *ND = E->getMemberDecl();
3872  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3873  LValue LV = EmitLValueForField(BaseLV, Field);
3874  setObjCGCLValueClass(getContext(), E, LV);
3875  return LV;
3876  }
3877 
3878  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3879  return EmitFunctionDeclLValue(*this, E, FD);
3880 
3881  llvm_unreachable("Unhandled member declaration!");
3882 }
3883 
3884 /// Given that we are currently emitting a lambda, emit an l-value for
3885 /// one of its members.
3887  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3888  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3889  QualType LambdaTagType =
3890  getContext().getTagDeclType(Field->getParent());
3891  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3892  return EmitLValueForField(LambdaLV, Field);
3893 }
3894 
3895 /// Get the field index in the debug info. The debug info structure/union
3896 /// will ignore the unnamed bitfields.
3898  unsigned FieldIndex) {
3899  unsigned I = 0, Skipped = 0;
3900 
3901  for (auto F : Rec->getDefinition()->fields()) {
3902  if (I == FieldIndex)
3903  break;
3904  if (F->isUnnamedBitfield())
3905  Skipped++;
3906  I++;
3907  }
3908 
3909  return FieldIndex - Skipped;
3910 }
3911 
3912 /// Get the address of a zero-sized field within a record. The resulting
3913 /// address doesn't necessarily have the right type.
3915  const FieldDecl *Field) {
3917  CGF.getContext().getFieldOffset(Field));
3918  if (Offset.isZero())
3919  return Base;
3920  Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty);
3921  return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
3922 }
3923 
3924 /// Drill down to the storage of a field without walking into
3925 /// reference types.
3926 ///
3927 /// The resulting address doesn't necessarily have the right type.
3929  const FieldDecl *field) {
3930  if (field->isZeroSize(CGF.getContext()))
3931  return emitAddrOfZeroSizeField(CGF, base, field);
3932 
3933  const RecordDecl *rec = field->getParent();
3934 
3935  unsigned idx =
3936  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3937 
3938  return CGF.Builder.CreateStructGEP(base, idx, field->getName());
3939 }
3940 
3942  const FieldDecl *field) {
3943  const RecordDecl *rec = field->getParent();
3944  llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateRecordType(
3945  CGF.getContext().getRecordType(rec), rec->getLocation());
3946 
3947  unsigned idx =
3948  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3949 
3951  base, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
3952 }
3953 
3954 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3955  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3956  if (!RD)
3957  return false;
3958 
3959  if (RD->isDynamicClass())
3960  return true;
3961 
3962  for (const auto &Base : RD->bases())
3963  if (hasAnyVptr(Base.getType(), Context))
3964  return true;
3965 
3966  for (const FieldDecl *Field : RD->fields())
3967  if (hasAnyVptr(Field->getType(), Context))
3968  return true;
3969 
3970  return false;
3971 }
3972 
3974  const FieldDecl *field) {
3975  LValueBaseInfo BaseInfo = base.getBaseInfo();
3976 
3977  if (field->isBitField()) {
3978  const CGRecordLayout &RL =
3980  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3981  Address Addr = base.getAddress();
3982  unsigned Idx = RL.getLLVMFieldNo(field);
3983  if (Idx != 0)
3984  // For structs, we GEP to the field that the record layout suggests.
3985  Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
3986  // Get the access type.
3987  llvm::Type *FieldIntTy =
3988  llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3989  if (Addr.getElementType() != FieldIntTy)
3990  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3991 
3992  QualType fieldType =
3993  field->getType().withCVRQualifiers(base.getVRQualifiers());
3994  // TODO: Support TBAA for bit fields.
3995  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
3996  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
3997  TBAAAccessInfo());
3998  }
3999 
4000  // Fields of may-alias structures are may-alias themselves.
4001  // FIXME: this should get propagated down through anonymous structs
4002  // and unions.
4003  QualType FieldType = field->getType();
4004  const RecordDecl *rec = field->getParent();
4005  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4006  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4007  TBAAAccessInfo FieldTBAAInfo;
4008  if (base.getTBAAInfo().isMayAlias() ||
4009  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4010  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4011  } else if (rec->isUnion()) {
4012  // TODO: Support TBAA for unions.
4013  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4014  } else {
4015  // If no base type been assigned for the base access, then try to generate
4016  // one for this base lvalue.
4017  FieldTBAAInfo = base.getTBAAInfo();
4018  if (!FieldTBAAInfo.BaseType) {
4019  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4020  assert(!FieldTBAAInfo.Offset &&
4021  "Nonzero offset for an access with no base type!");
4022  }
4023 
4024  // Adjust offset to be relative to the base type.
4025  const ASTRecordLayout &Layout =
4027  unsigned CharWidth = getContext().getCharWidth();
4028  if (FieldTBAAInfo.BaseType)
4029  FieldTBAAInfo.Offset +=
4030  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4031 
4032  // Update the final access type and size.
4033  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4034  FieldTBAAInfo.Size =
4035  getContext().getTypeSizeInChars(FieldType).getQuantity();
4036  }
4037 
4038  Address addr = base.getAddress();
4039  if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4040  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4041  ClassDef->isDynamicClass()) {
4042  // Getting to any field of dynamic object requires stripping dynamic
4043  // information provided by invariant.group. This is because accessing
4044  // fields may leak the real address of dynamic object, which could result
4045  // in miscompilation when leaked pointer would be compared.
4046  auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4047  addr = Address(stripped, addr.getAlignment());
4048  }
4049  }
4050 
4051  unsigned RecordCVR = base.getVRQualifiers();
4052  if (rec->isUnion()) {
4053  // For unions, there is no pointer adjustment.
4054  assert(!FieldType->isReferenceType() && "union has reference member");
4055  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4056  hasAnyVptr(FieldType, getContext()))
4057  // Because unions can easily skip invariant.barriers, we need to add
4058  // a barrier every time CXXRecord field with vptr is referenced.
4059  addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
4060  addr.getAlignment());
4061 
4062  if (IsInPreservedAIRegion) {
4063  // Remember the original union field index
4064  llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4065  getContext().getRecordType(rec), rec->getLocation());
4066  addr = Address(
4067  Builder.CreatePreserveUnionAccessIndex(
4068  addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4069  addr.getAlignment());
4070  }
4071  } else {
4072 
4073  if (!IsInPreservedAIRegion)
4074  // For structs, we GEP to the field that the record layout suggests.
4075  addr = emitAddrOfFieldStorage(*this, addr, field);
4076  else
4077  // Remember the original struct field index
4078  addr = emitPreserveStructAccess(*this, addr, field);
4079 
4080  // If this is a reference field, load the reference right now.
4081  if (FieldType->isReferenceType()) {
4082  LValue RefLVal = MakeAddrLValue(addr, FieldType, FieldBaseInfo,
4083  FieldTBAAInfo);
4084  if (RecordCVR & Qualifiers::Volatile)
4085  RefLVal.getQuals().addVolatile();
4086  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4087 
4088  // Qualifiers on the struct don't apply to the referencee.
4089  RecordCVR = 0;
4090  FieldType = FieldType->getPointeeType();
4091  }
4092  }
4093 
4094  // Make sure that the address is pointing to the right type. This is critical
4095  // for both unions and structs. A union needs a bitcast, a struct element
4096  // will need a bitcast if the LLVM type laid out doesn't match the desired
4097  // type.
4099  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4100 
4101  if (field->hasAttr<AnnotateAttr>())
4102  addr = EmitFieldAnnotations(field, addr);
4103 
4104  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4105  LV.getQuals().addCVRQualifiers(RecordCVR);
4106 
4107  // __weak attribute on a field is ignored.
4108  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4109  LV.getQuals().removeObjCGCAttr();
4110 
4111  return LV;
4112 }
4113 
4114 LValue
4116  const FieldDecl *Field) {
4117  QualType FieldType = Field->getType();
4118 
4119  if (!FieldType->isReferenceType())
4120  return EmitLValueForField(Base, Field);
4121 
4122  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
4123 
4124  // Make sure that the address is pointing to the right type.
4125  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4126  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4127 
4128  // TODO: Generate TBAA information that describes this access as a structure
4129  // member access and not just an access to an object of the field's type. This
4130  // should be similar to what we do in EmitLValueForField().
4131  LValueBaseInfo BaseInfo = Base.getBaseInfo();
4132  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4133  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4134  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4135  CGM.getTBAAInfoForSubobject(Base, FieldType));
4136 }
4137 
4139  if (E->isFileScope()) {
4141  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4142  }
4143  if (E->getType()->isVariablyModifiedType())
4144  // make sure to emit the VLA size.
4146 
4147  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4148  const Expr *InitExpr = E->getInitializer();
4149  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4150 
4151  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4152  /*Init*/ true);
4153 
4154  return Result;
4155 }
4156 
4158  if (!E->isGLValue())
4159  // Initializing an aggregate temporary in C++11: T{...}.
4160  return EmitAggExprToLValue(E);
4161 
4162  // An lvalue initializer list must be initializing a reference.
4163  assert(E->isTransparent() && "non-transparent glvalue init list");
4164  return EmitLValue(E->getInit(0));
4165 }
4166 
4167 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4168 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4169 /// LValue is returned and the current block has been terminated.
4171  const Expr *Operand) {
4172  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4173  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4174  return None;
4175  }
4176 
4177  return CGF.EmitLValue(Operand);
4178 }
4179 
4182  if (!expr->isGLValue()) {
4183  // ?: here should be an aggregate.
4184  assert(hasAggregateEvaluationKind(expr->getType()) &&
4185  "Unexpected conditional operator!");
4186  return EmitAggExprToLValue(expr);
4187  }
4188 
4189  OpaqueValueMapping binding(*this, expr);
4190 
4191  const Expr *condExpr = expr->getCond();
4192  bool CondExprBool;
4193  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4194  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4195  if (!CondExprBool) std::swap(live, dead);
4196 
4197  if (!ContainsLabel(dead)) {
4198  // If the true case is live, we need to track its region.
4199  if (CondExprBool)
4201  return EmitLValue(live);
4202  }
4203  }
4204 
4205  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4206  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4207  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4208 
4209  ConditionalEvaluation eval(*this);
4210  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4211 
4212  // Any temporaries created here are conditional.
4213  EmitBlock(lhsBlock);
4215  eval.begin(*this);
4216  Optional<LValue> lhs =
4217  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4218  eval.end(*this);
4219 
4220  if (lhs && !lhs->isSimple())
4221  return EmitUnsupportedLValue(expr, "conditional operator");
4222 
4223  lhsBlock = Builder.GetInsertBlock();
4224  if (lhs)
4225  Builder.CreateBr(contBlock);
4226 
4227  // Any temporaries created here are conditional.
4228  EmitBlock(rhsBlock);
4229  eval.begin(*this);
4230  Optional<LValue> rhs =
4231  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4232  eval.end(*this);
4233  if (rhs && !rhs->isSimple())
4234  return EmitUnsupportedLValue(expr, "conditional operator");
4235  rhsBlock = Builder.GetInsertBlock();
4236 
4237  EmitBlock(contBlock);
4238 
4239  if (lhs && rhs) {
4240  llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4241  2, "cond-lvalue");
4242  phi->addIncoming(lhs->getPointer(), lhsBlock);
4243  phi->addIncoming(rhs->getPointer(), rhsBlock);
4244  Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4245  AlignmentSource alignSource =
4246  std::max(lhs->getBaseInfo().getAlignmentSource(),
4247  rhs->getBaseInfo().getAlignmentSource());
4249  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4250  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4251  TBAAInfo);
4252  } else {
4253  assert((lhs || rhs) &&
4254  "both operands of glvalue conditional are throw-expressions?");
4255  return lhs ? *lhs : *rhs;
4256  }
4257 }
4258 
4259 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4260 /// type. If the cast is to a reference, we can have the usual lvalue result,
4261 /// otherwise if a cast is needed by the code generator in an lvalue context,
4262 /// then it must mean that we need the address of an aggregate in order to
4263 /// access one of its members. This can happen for all the reasons that casts
4264 /// are permitted with aggregate result, including noop aggregate casts, and
4265 /// cast from scalar to union.
4267  switch (E->getCastKind()) {
4268  case CK_ToVoid:
4269  case CK_BitCast:
4270  case CK_LValueToRValueBitCast:
4271  case CK_ArrayToPointerDecay:
4272  case CK_FunctionToPointerDecay:
4273  case CK_NullToMemberPointer:
4274  case CK_NullToPointer:
4275  case CK_IntegralToPointer:
4276  case CK_PointerToIntegral:
4277  case CK_PointerToBoolean:
4278  case CK_VectorSplat:
4279  case CK_IntegralCast:
4280  case CK_BooleanToSignedIntegral:
4281  case CK_IntegralToBoolean:
4282  case CK_IntegralToFloating:
4283  case CK_FloatingToIntegral:
4284  case CK_FloatingToBoolean:
4285  case CK_FloatingCast:
4286  case CK_FloatingRealToComplex:
4287  case CK_FloatingComplexToReal:
4288  case CK_FloatingComplexToBoolean:
4289  case CK_FloatingComplexCast:
4290  case CK_FloatingComplexToIntegralComplex:
4291  case CK_IntegralRealToComplex:
4292  case CK_IntegralComplexToReal:
4293  case CK_IntegralComplexToBoolean:
4294  case CK_IntegralComplexCast:
4295  case CK_IntegralComplexToFloatingComplex:
4296  case CK_DerivedToBaseMemberPointer:
4297  case CK_BaseToDerivedMemberPointer:
4298  case CK_MemberPointerToBoolean:
4299  case CK_ReinterpretMemberPointer:
4300  case CK_AnyPointerToBlockPointerCast:
4301  case CK_ARCProduceObject:
4302  case CK_ARCConsumeObject:
4303  case CK_ARCReclaimReturnedObject:
4304  case CK_ARCExtendBlockObject:
4305  case CK_CopyAndAutoreleaseBlockObject:
4306  case CK_IntToOCLSampler:
4307  case CK_FixedPointCast:
4308  case CK_FixedPointToBoolean:
4309  case CK_FixedPointToIntegral:
4310  case CK_IntegralToFixedPoint:
4311  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4312 
4313  case CK_Dependent:
4314  llvm_unreachable("dependent cast kind in IR gen!");
4315 
4316  case CK_BuiltinFnToFnPtr:
4317  llvm_unreachable("builtin functions are handled elsewhere");
4318 
4319  // These are never l-values; just use the aggregate emission code.
4320  case CK_NonAtomicToAtomic:
4321  case CK_AtomicToNonAtomic:
4322  return EmitAggExprToLValue(E);
4323 
4324  case CK_Dynamic: {
4325  LValue LV = EmitLValue(E->getSubExpr());
4326  Address V = LV.getAddress();
4327  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4328  return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4329  }
4330 
4331  case CK_ConstructorConversion:
4332  case CK_UserDefinedConversion:
4333  case CK_CPointerToObjCPointerCast:
4334  case CK_BlockPointerToObjCPointerCast:
4335  case CK_NoOp:
4336  case CK_LValueToRValue:
4337  return EmitLValue(E->getSubExpr());
4338 
4339  case CK_UncheckedDerivedToBase:
4340  case CK_DerivedToBase: {
4341  const RecordType *DerivedClassTy =
4342  E->getSubExpr()->getType()->getAs<RecordType>();
4343  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4344 
4345  LValue LV = EmitLValue(E->getSubExpr());
4346  Address This = LV.getAddress();
4347 
4348  // Perform the derived-to-base conversion
4350  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4351  /*NullCheckValue=*/false, E->getExprLoc());
4352 
4353  // TODO: Support accesses to members of base classes in TBAA. For now, we
4354  // conservatively pretend that the complete object is of the base class
4355  // type.
4356  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4357  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4358  }
4359  case CK_ToUnion:
4360  return EmitAggExprToLValue(E);
4361  case CK_BaseToDerived: {
4362  const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4363  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4364 
4365  LValue LV = EmitLValue(E->getSubExpr());
4366 
4367  // Perform the base-to-derived conversion
4368  Address Derived =
4369  GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4370  E->path_begin(), E->path_end(),
4371  /*NullCheckValue=*/false);
4372 
4373  // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4374  // performed and the object is not of the derived type.
4377  Derived.getPointer(), E->getType());
4378 
4379  if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4380  EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4381  /*MayBeNull=*/false, CFITCK_DerivedCast,
4382  E->getBeginLoc());
4383 
4384  return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4385  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4386  }
4387  case CK_LValueBitCast: {
4388  // This must be a reinterpret_cast (or c-style equivalent).
4389  const auto *CE = cast<ExplicitCastExpr>(E);
4390 
4391  CGM.EmitExplicitCastExprType(CE, this);
4392  LValue LV = EmitLValue(E->getSubExpr());
4394  ConvertType(CE->getTypeAsWritten()));
4395 
4396  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4397  EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4398  /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4399  E->getBeginLoc());
4400 
4401  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4402  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4403  }
4404  case CK_AddressSpaceConversion: {
4405  LValue LV = EmitLValue(E->getSubExpr());
4406  QualType DestTy = getContext().getPointerType(E->getType());
4408  *this, LV.getPointer(), E->getSubExpr()->getType().getAddressSpace(),
4409  E->getType().getAddressSpace(), ConvertType(DestTy));
4410  return MakeAddrLValue(Address(V, LV.getAddress().getAlignment()),
4411  E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4412  }
4413  case CK_ObjCObjectLValueCast: {
4414  LValue LV = EmitLValue(E->getSubExpr());
4416  ConvertType(E->getType()));
4417  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4418  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4419  }
4420  case CK_ZeroToOCLOpaqueType:
4421  llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4422  }
4423 
4424  llvm_unreachable("Unhandled lvalue cast kind?");
4425 }
4426 
4430 }
4431 
4432 LValue
4435 
4436  llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4437  it = OpaqueLValues.find(e);
4438 
4439  if (it != OpaqueLValues.end())
4440  return it->second;
4441 
4442  assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4443  return EmitLValue(e->getSourceExpr());
4444 }
4445 
4446 RValue
4449 
4450  llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4451  it = OpaqueRValues.find(e);
4452 
4453  if (it != OpaqueRValues.end())
4454  return it->second;
4455 
4456  assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4457  return EmitAnyExpr(e->getSourceExpr());
4458 }
4459 
4461  const FieldDecl *FD,
4462  SourceLocation Loc) {
4463  QualType FT = FD->getType();
4464  LValue FieldLV = EmitLValueForField(LV, FD);
4465  switch (getEvaluationKind(FT)) {
4466  case TEK_Complex:
4467  return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4468  case TEK_Aggregate:
4469  return FieldLV.asAggregateRValue();
4470  case TEK_Scalar:
4471  // This routine is used to load fields one-by-one to perform a copy, so
4472  // don't load reference fields.
4473  if (FD->getType()->isReferenceType())
4474  return RValue::get(FieldLV.getPointer());
4475  return EmitLoadOfLValue(FieldLV, Loc);
4476  }
4477  llvm_unreachable("bad evaluation kind");
4478 }
4479 
4480 //===--------------------------------------------------------------------===//
4481 // Expression Emission
4482 //===--------------------------------------------------------------------===//
4483 
4486  // Builtins never have block type.
4487  if (E->getCallee()->getType()->isBlockPointerType())
4488  return EmitBlockCallExpr(E, ReturnValue);
4489 
4490  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4491  return EmitCXXMemberCallExpr(CE, ReturnValue);
4492 
4493  if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4494  return EmitCUDAKernelCallExpr(CE, ReturnValue);
4495 
4496  if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4497  if (const CXXMethodDecl *MD =
4498  dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4499  return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4500 
4501  CGCallee callee = EmitCallee(E->getCallee());
4502 
4503  if (callee.isBuiltin()) {
4504  return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4505  E, ReturnValue);
4506  }
4507 
4508  if (callee.isPseudoDestructor()) {
4510  }
4511 
4512  return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4513 }
4514 
4515 /// Emit a CallExpr without considering whether it might be a subclass.
4518  CGCallee Callee = EmitCallee(E->getCallee());
4519  return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4520 }
4521 
4523  if (auto builtinID = FD->getBuiltinID()) {
4524  return CGCallee::forBuiltin(builtinID, FD);
4525  }
4526 
4527  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4528  return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
4529 }
4530 
4532  E = E->IgnoreParens();
4533 
4534  // Look through function-to-pointer decay.
4535  if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4536  if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4537  ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4538  return EmitCallee(ICE->getSubExpr());
4539  }
4540 
4541  // Resolve direct calls.
4542  } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4543  if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4544  return EmitDirectCallee(*this, FD);
4545  }
4546  } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4547  if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4548  EmitIgnoredExpr(ME->getBase());
4549  return EmitDirectCallee(*this, FD);
4550  }
4551 
4552  // Look through template substitutions.
4553  } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4554  return EmitCallee(NTTP->getReplacement());
4555 
4556  // Treat pseudo-destructor calls differently.
4557  } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4558  return CGCallee::forPseudoDestructor(PDE);
4559  }
4560 
4561  // Otherwise, we have an indirect reference.
4562  llvm::Value *calleePtr;
4564  if (auto ptrType = E->getType()->getAs<PointerType>()) {
4565  calleePtr = EmitScalarExpr(E);
4566  functionType = ptrType->getPointeeType();
4567  } else {
4568  functionType = E->getType();
4569  calleePtr = EmitLValue(E).getPointer();
4570  }
4571  assert(functionType->isFunctionType());
4572 
4573  GlobalDecl GD;
4574  if (const auto *VD =
4575  dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4576  GD = GlobalDecl(VD);
4577 
4578  CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4579  CGCallee callee(calleeInfo, calleePtr);
4580  return callee;
4581 }
4582 
4584  // Comma expressions just emit their LHS then their RHS as an l-value.
4585  if (E->getOpcode() == BO_Comma) {
4586  EmitIgnoredExpr(E->getLHS());
4588  return EmitLValue(E->getRHS());
4589  }
4590 
4591  if (E->getOpcode() == BO_PtrMemD ||
4592  E->getOpcode() == BO_PtrMemI)
4594 
4595  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4596 
4597  // Note that in all of these cases, __block variables need the RHS
4598  // evaluated first just in case the variable gets moved by the RHS.
4599 
4600  switch (getEvaluationKind(E->getType())) {
4601  case TEK_Scalar: {
4602  switch (E->getLHS()->getType().getObjCLifetime()) {
4604  return EmitARCStoreStrong(E, /*ignored*/ false).first;
4605 
4607  return EmitARCStoreAutoreleasing(E).first;
4608 
4609  // No reason to do any of these differently.
4610  case Qualifiers::OCL_None:
4612  case Qualifiers::OCL_Weak:
4613  break;
4614  }
4615 
4616  RValue RV = EmitAnyExpr(E->getRHS());
4618  if (RV.isScalar())
4620  EmitStoreThroughLValue(RV, LV);
4621  return LV;
4622  }
4623 
4624  case TEK_Complex:
4625  return EmitComplexAssignmentLValue(E);
4626 
4627  case TEK_Aggregate:
4628  return EmitAggExprToLValue(E);
4629  }
4630  llvm_unreachable("bad evaluation kind");
4631 }
4632 
4634  RValue RV = EmitCallExpr(E);
4635 
4636  if (!RV.isScalar())
4637  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4639 
4640  assert(E->getCallReturnType(getContext())->isReferenceType() &&
4641  "Can't have a scalar return unless the return type is a "
4642  "reference type!");
4643 
4645 }
4646 
4648  // FIXME: This shouldn't require another copy.
4649  return EmitAggExprToLValue(E);
4650 }
4651 
4654  && "binding l-value to type which needs a temporary");
4655  AggValueSlot Slot = CreateAggTemp(E->getType());
4656  EmitCXXConstructExpr(E, Slot);
4657  return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4658 }
4659 
4660 LValue
4663 }
4664 
4667  ConvertType(E->getType()));
4668 }
4669 
4671  return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4673 }
4674 
4675 LValue
4677  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4678  Slot.setExternallyDestructed();
4679  EmitAggExpr(E->getSubExpr(), Slot);
4680  EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4682 }
4683 
4685  RValue RV = EmitObjCMessageExpr(E);
4686 
4687  if (!RV.isScalar())
4688  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4690 
4691  assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4692  "Can't have a scalar return unless the return type is a "
4693  "reference type!");
4694 
4696 }
4697 
4699  Address V =
4701  return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4702 }
4703 
4705  const ObjCIvarDecl *Ivar) {
4706  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4707 }
4708 
4710  llvm::Value *BaseValue,
4711  const ObjCIvarDecl *Ivar,
4712  unsigned CVRQualifiers) {
4713  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4714  Ivar, CVRQualifiers);
4715 }
4716 
4718  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4719  llvm::Value *BaseValue = nullptr;
4720  const Expr *BaseExpr = E->getBase();
4721  Qualifiers BaseQuals;
4722  QualType ObjectTy;
4723  if (E->isArrow()) {
4724  BaseValue = EmitScalarExpr(BaseExpr);
4725  ObjectTy = BaseExpr->getType()->getPointeeType();
4726  BaseQuals = ObjectTy.getQualifiers();
4727  } else {
4728  LValue BaseLV = EmitLValue(BaseExpr);
4729  BaseValue = BaseLV.getPointer();
4730  ObjectTy = BaseExpr->getType();
4731  BaseQuals = ObjectTy.getQualifiers();
4732  }
4733 
4734  LValue LV =
4735  EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4736  BaseQuals.getCVRQualifiers());
4737  setObjCGCLValueClass(getContext(), E, LV);
4738  return LV;
4739 }
4740 
4742  // Can only get l-value for message expression returning aggregate type
4743  RValue RV = EmitAnyExprToTemp(E);
4744  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4746 }
4747 
4748 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4750  llvm::Value *Chain) {
4751  // Get the actual function type. The callee type will always be a pointer to
4752  // function type or a block pointer type.
4753  assert(CalleeType->isFunctionPointerType() &&
4754  "Call must have function pointer type!");
4755 
4756  const Decl *TargetDecl =
4757  OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
4758 
4759  CalleeType = getContext().getCanonicalType(CalleeType);
4760 
4761  auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4762 
4763  CGCallee Callee = OrigCallee;
4764 
4766  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4767  if (llvm::Constant *PrefixSig =
4769  SanitizerScope SanScope(this);
4770  // Remove any (C++17) exception specifications, to allow calling e.g. a
4771  // noexcept function through a non-noexcept pointer.
4772  auto ProtoTy =
4774  llvm::Constant *FTRTTIConst =
4775  CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4776  ll