clang  9.0.0svn
CGExpr.cpp
Go to the documentation of this file.
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"
29 #include "llvm/ADT/Hashing.h"
30 #include "llvm/ADT/StringExtras.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/Intrinsics.h"
33 #include "llvm/IR/LLVMContext.h"
34 #include "llvm/IR/MDBuilder.h"
35 #include "llvm/Support/ConvertUTF.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Support/Path.h"
38 #include "llvm/Transforms/Utils/SanitizerStats.h"
39 
40 #include <string>
41 
42 using namespace clang;
43 using namespace CodeGen;
44 
45 //===--------------------------------------------------------------------===//
46 // Miscellaneous Helper Methods
47 //===--------------------------------------------------------------------===//
48 
50  unsigned addressSpace =
51  cast<llvm::PointerType>(value->getType())->getAddressSpace();
52 
53  llvm::PointerType *destType = Int8PtrTy;
54  if (addressSpace)
55  destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
56 
57  if (value->getType() == destType) return value;
58  return Builder.CreateBitCast(value, destType);
59 }
60 
61 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
62 /// block.
64  CharUnits Align,
65  const Twine &Name,
66  llvm::Value *ArraySize) {
67  auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
68  Alloca->setAlignment(Align.getQuantity());
69  return Address(Alloca, Align);
70 }
71 
72 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
73 /// block. The alloca is casted to default address space if necessary.
75  const Twine &Name,
76  llvm::Value *ArraySize,
77  Address *AllocaAddr) {
78  auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
79  if (AllocaAddr)
80  *AllocaAddr = Alloca;
81  llvm::Value *V = Alloca.getPointer();
82  // Alloca always returns a pointer in alloca address space, which may
83  // be different from the type defined by the language. For example,
84  // in C++ the auto variables are in the default address space. Therefore
85  // cast alloca to the default address space when necessary.
87  auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
88  llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
89  // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
90  // otherwise alloca is inserted at the current insertion point of the
91  // builder.
92  if (!ArraySize)
93  Builder.SetInsertPoint(AllocaInsertPt);
96  Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
97  }
98 
99  return Address(V, Align);
100 }
101 
102 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
103 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
104 /// insertion point of the builder.
106  const Twine &Name,
107  llvm::Value *ArraySize) {
108  if (ArraySize)
109  return Builder.CreateAlloca(Ty, ArraySize, Name);
110  return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
111  ArraySize, Name, AllocaInsertPt);
112 }
113 
114 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
115 /// default alignment of the corresponding LLVM type, which is *not*
116 /// guaranteed to be related in any way to the expected alignment of
117 /// an AST type that might have been lowered to Ty.
119  const Twine &Name) {
120  CharUnits Align =
121  CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
122  return CreateTempAlloca(Ty, Align, Name);
123 }
124 
126  assert(isa<llvm::AllocaInst>(Var.getPointer()));
127  auto *Store = new llvm::StoreInst(Init, Var.getPointer());
128  Store->setAlignment(Var.getAlignment().getQuantity());
129  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
130  Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
131 }
132 
135  return CreateTempAlloca(ConvertType(Ty), Align, Name);
136 }
137 
139  Address *Alloca) {
140  // FIXME: Should we prefer the preferred type alignment here?
141  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
142 }
143 
145  const Twine &Name, Address *Alloca) {
146  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
147  /*ArraySize=*/nullptr, Alloca);
148 }
149 
151  const Twine &Name) {
152  return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
153 }
154 
156  const Twine &Name) {
157  return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
158  Name);
159 }
160 
161 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
162 /// expression and compare the result against zero, returning an Int1Ty value.
164  PGO.setCurrentStmt(E);
165  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
166  llvm::Value *MemPtr = EmitScalarExpr(E);
167  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
168  }
169 
170  QualType BoolTy = getContext().BoolTy;
171  SourceLocation Loc = E->getExprLoc();
172  if (!E->getType()->isAnyComplexType())
173  return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
174 
175  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
176  Loc);
177 }
178 
179 /// EmitIgnoredExpr - Emit code to compute the specified expression,
180 /// ignoring the result.
182  if (E->isRValue())
183  return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
184 
185  // Just emit it as an l-value and drop the result.
186  EmitLValue(E);
187 }
188 
189 /// EmitAnyExpr - Emit code to compute the specified expression which
190 /// can have any type. The result is returned as an RValue struct.
191 /// If this is an aggregate expression, AggSlot indicates where the
192 /// result should be returned.
194  AggValueSlot aggSlot,
195  bool ignoreResult) {
196  switch (getEvaluationKind(E->getType())) {
197  case TEK_Scalar:
198  return RValue::get(EmitScalarExpr(E, ignoreResult));
199  case TEK_Complex:
200  return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
201  case TEK_Aggregate:
202  if (!ignoreResult && aggSlot.isIgnored())
203  aggSlot = CreateAggTemp(E->getType(), "agg-temp");
204  EmitAggExpr(E, aggSlot);
205  return aggSlot.asRValue();
206  }
207  llvm_unreachable("bad evaluation kind");
208 }
209 
210 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
211 /// always be accessible even if no aggregate location is provided.
214 
216  AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
217  return EmitAnyExpr(E, AggSlot);
218 }
219 
220 /// EmitAnyExprToMem - Evaluate an expression into a given memory
221 /// location.
223  Address Location,
224  Qualifiers Quals,
225  bool IsInit) {
226  // FIXME: This function should take an LValue as an argument.
227  switch (getEvaluationKind(E->getType())) {
228  case TEK_Complex:
230  /*isInit*/ false);
231  return;
232 
233  case TEK_Aggregate: {
234  EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
237  AggValueSlot::IsAliased_t(!IsInit),
239  return;
240  }
241 
242  case TEK_Scalar: {
243  RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
244  LValue LV = MakeAddrLValue(Location, E->getType());
245  EmitStoreThroughLValue(RV, LV);
246  return;
247  }
248  }
249  llvm_unreachable("bad evaluation kind");
250 }
251 
252 static void
254  const Expr *E, Address ReferenceTemporary) {
255  // Objective-C++ ARC:
256  // If we are binding a reference to a temporary that has ownership, we
257  // need to perform retain/release operations on the temporary.
258  //
259  // FIXME: This should be looking at E, not M.
260  if (auto Lifetime = M->getType().getObjCLifetime()) {
261  switch (Lifetime) {
264  // Carry on to normal cleanup handling.
265  break;
266 
268  // Nothing to do; cleaned up by an autorelease pool.
269  return;
270 
273  switch (StorageDuration Duration = M->getStorageDuration()) {
274  case SD_Static:
275  // Note: we intentionally do not register a cleanup to release
276  // the object on program termination.
277  return;
278 
279  case SD_Thread:
280  // FIXME: We should probably register a cleanup in this case.
281  return;
282 
283  case SD_Automatic:
284  case SD_FullExpression:
287  if (Lifetime == Qualifiers::OCL_Strong) {
288  const ValueDecl *VD = M->getExtendingDecl();
289  bool Precise =
290  VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
291  CleanupKind = CGF.getARCCleanupKind();
292  Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
294  } else {
295  // __weak objects always get EH cleanups; otherwise, exceptions
296  // could cause really nasty crashes instead of mere leaks.
297  CleanupKind = NormalAndEHCleanup;
299  }
300  if (Duration == SD_FullExpression)
301  CGF.pushDestroy(CleanupKind, ReferenceTemporary,
302  M->getType(), *Destroy,
303  CleanupKind & EHCleanup);
304  else
305  CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
306  M->getType(),
307  *Destroy, CleanupKind & EHCleanup);
308  return;
309 
310  case SD_Dynamic:
311  llvm_unreachable("temporary cannot have dynamic storage duration");
312  }
313  llvm_unreachable("unknown storage duration");
314  }
315  }
316 
317  CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
318  if (const RecordType *RT =
320  // Get the destructor for the reference temporary.
321  auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
322  if (!ClassDecl->hasTrivialDestructor())
323  ReferenceTemporaryDtor = ClassDecl->getDestructor();
324  }
325 
326  if (!ReferenceTemporaryDtor)
327  return;
328 
329  // Call the destructor for the temporary.
330  switch (M->getStorageDuration()) {
331  case SD_Static:
332  case SD_Thread: {
333  llvm::FunctionCallee CleanupFn;
334  llvm::Constant *CleanupArg;
335  if (E->getType()->isArrayType()) {
336  CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
337  ReferenceTemporary, E->getType(),
339  dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
340  CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
341  } else {
342  CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
343  GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
344  CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
345  }
347  CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
348  break;
349  }
350 
351  case SD_FullExpression:
352  CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
354  CGF.getLangOpts().Exceptions);
355  break;
356 
357  case SD_Automatic:
359  ReferenceTemporary, E->getType(),
361  CGF.getLangOpts().Exceptions);
362  break;
363 
364  case SD_Dynamic:
365  llvm_unreachable("temporary cannot have dynamic storage duration");
366  }
367 }
368 
370  const MaterializeTemporaryExpr *M,
371  const Expr *Inner,
372  Address *Alloca = nullptr) {
373  auto &TCG = CGF.getTargetHooks();
374  switch (M->getStorageDuration()) {
375  case SD_FullExpression:
376  case SD_Automatic: {
377  // If we have a constant temporary array or record try to promote it into a
378  // constant global under the same rules a normal constant would've been
379  // promoted. This is easier on the optimizer and generally emits fewer
380  // instructions.
381  QualType Ty = Inner->getType();
382  if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
383  (Ty->isArrayType() || Ty->isRecordType()) &&
384  CGF.CGM.isTypeConstant(Ty, true))
385  if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
386  if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
387  auto AS = AddrSpace.getValue();
388  auto *GV = new llvm::GlobalVariable(
389  CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
390  llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
391  llvm::GlobalValue::NotThreadLocal,
393  CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
394  GV->setAlignment(alignment.getQuantity());
395  llvm::Constant *C = GV;
396  if (AS != LangAS::Default)
397  C = TCG.performAddrSpaceCast(
398  CGF.CGM, GV, AS, LangAS::Default,
399  GV->getValueType()->getPointerTo(
401  // FIXME: Should we put the new global into a COMDAT?
402  return Address(C, alignment);
403  }
404  }
405  return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
406  }
407  case SD_Thread:
408  case SD_Static:
409  return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
410 
411  case SD_Dynamic:
412  llvm_unreachable("temporary can't have dynamic storage duration");
413  }
414  llvm_unreachable("unknown storage duration");
415 }
416 
419  const Expr *E = M->GetTemporaryExpr();
420 
421  assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
422  !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
423  "Reference should never be pseudo-strong!");
424 
425  // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
426  // as that will cause the lifetime adjustment to be lost for ARC
427  auto ownership = M->getType().getObjCLifetime();
428  if (ownership != Qualifiers::OCL_None &&
429  ownership != Qualifiers::OCL_ExplicitNone) {
430  Address Object = createReferenceTemporary(*this, M, E);
431  if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
432  Object = Address(llvm::ConstantExpr::getBitCast(Var,
434  ->getPointerTo(Object.getAddressSpace())),
435  Object.getAlignment());
436 
437  // createReferenceTemporary will promote the temporary to a global with a
438  // constant initializer if it can. It can only do this to a value of
439  // ARC-manageable type if the value is global and therefore "immune" to
440  // ref-counting operations. Therefore we have no need to emit either a
441  // dynamic initialization or a cleanup and we can just return the address
442  // of the temporary.
443  if (Var->hasInitializer())
444  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
445 
446  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
447  }
448  LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
450 
451  switch (getEvaluationKind(E->getType())) {
452  default: llvm_unreachable("expected scalar or aggregate expression");
453  case TEK_Scalar:
454  EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
455  break;
456  case TEK_Aggregate: {
458  E->getType().getQualifiers(),
463  break;
464  }
465  }
466 
467  pushTemporaryCleanup(*this, M, E, Object);
468  return RefTempDst;
469  }
470 
473  E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
474 
475  for (const auto &Ignored : CommaLHSs)
476  EmitIgnoredExpr(Ignored);
477 
478  if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
479  if (opaque->getType()->isRecordType()) {
480  assert(Adjustments.empty());
481  return EmitOpaqueValueLValue(opaque);
482  }
483  }
484 
485  // Create and initialize the reference temporary.
486  Address Alloca = Address::invalid();
487  Address Object = createReferenceTemporary(*this, M, E, &Alloca);
488  if (auto *Var = dyn_cast<llvm::GlobalVariable>(
489  Object.getPointer()->stripPointerCasts())) {
490  Object = Address(llvm::ConstantExpr::getBitCast(
491  cast<llvm::Constant>(Object.getPointer()),
492  ConvertTypeForMem(E->getType())->getPointerTo()),
493  Object.getAlignment());
494  // If the temporary is a global and has a constant initializer or is a
495  // constant temporary that we promoted to a global, we may have already
496  // initialized it.
497  if (!Var->hasInitializer()) {
498  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
499  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
500  }
501  } else {
502  switch (M->getStorageDuration()) {
503  case SD_Automatic:
504  if (auto *Size = EmitLifetimeStart(
505  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
506  Alloca.getPointer())) {
507  pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
508  Alloca, Size);
509  }
510  break;
511 
512  case SD_FullExpression: {
513  if (!ShouldEmitLifetimeMarkers)
514  break;
515 
516  // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
517  // marker. Instead, start the lifetime of a conditional temporary earlier
518  // so that it's unconditional. Don't do this in ASan's use-after-scope
519  // mode so that it gets the more precise lifetime marks. If the type has
520  // a non-trivial destructor, we'll have a cleanup block for it anyway,
521  // so this typically doesn't help; skip it in that case.
522  ConditionalEvaluation *OldConditional = nullptr;
523  CGBuilderTy::InsertPoint OldIP;
525  !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
526  OldConditional = OutermostConditional;
527  OutermostConditional = nullptr;
528 
529  OldIP = Builder.saveIP();
530  llvm::BasicBlock *Block = OldConditional->getStartingBlock();
531  Builder.restoreIP(CGBuilderTy::InsertPoint(
532  Block, llvm::BasicBlock::iterator(Block->back())));
533  }
534 
535  if (auto *Size = EmitLifetimeStart(
536  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
537  Alloca.getPointer())) {
538  pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
539  Size);
540  }
541 
542  if (OldConditional) {
543  OutermostConditional = OldConditional;
544  Builder.restoreIP(OldIP);
545  }
546  break;
547  }
548 
549  default:
550  break;
551  }
552  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
553  }
554  pushTemporaryCleanup(*this, M, E, Object);
555 
556  // Perform derived-to-base casts and/or field accesses, to get from the
557  // temporary object we created (and, potentially, for which we extended
558  // the lifetime) to the subobject we're binding the reference to.
559  for (unsigned I = Adjustments.size(); I != 0; --I) {
560  SubobjectAdjustment &Adjustment = Adjustments[I-1];
561  switch (Adjustment.Kind) {
563  Object =
565  Adjustment.DerivedToBase.BasePath->path_begin(),
566  Adjustment.DerivedToBase.BasePath->path_end(),
567  /*NullCheckValue=*/ false, E->getExprLoc());
568  break;
569 
572  LV = EmitLValueForField(LV, Adjustment.Field);
573  assert(LV.isSimple() &&
574  "materialized temporary field is not a simple lvalue");
575  Object = LV.getAddress();
576  break;
577  }
578 
580  llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
581  Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
582  Adjustment.Ptr.MPT);
583  break;
584  }
585  }
586  }
587 
588  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
589 }
590 
591 RValue
593  // Emit the expression as an lvalue.
594  LValue LV = EmitLValue(E);
595  assert(LV.isSimple());
596  llvm::Value *Value = LV.getPointer();
597 
598  if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
599  // C++11 [dcl.ref]p5 (as amended by core issue 453):
600  // If a glvalue to which a reference is directly bound designates neither
601  // an existing object or function of an appropriate type nor a region of
602  // storage of suitable size and alignment to contain an object of the
603  // reference's type, the behavior is undefined.
604  QualType Ty = E->getType();
606  }
607 
608  return RValue::get(Value);
609 }
610 
611 
612 /// getAccessedFieldNo - Given an encoded value and a result number, return the
613 /// input field number being accessed.
615  const llvm::Constant *Elts) {
616  return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
617  ->getZExtValue();
618 }
619 
620 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
622  llvm::Value *High) {
623  llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
624  llvm::Value *K47 = Builder.getInt64(47);
625  llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
626  llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
627  llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
628  llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
629  return Builder.CreateMul(B1, KMul);
630 }
631 
633  return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
635 }
636 
638  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
639  return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
640  (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
641  TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
643 }
644 
646  return SanOpts.has(SanitizerKind::Null) |
647  SanOpts.has(SanitizerKind::Alignment) |
648  SanOpts.has(SanitizerKind::ObjectSize) |
649  SanOpts.has(SanitizerKind::Vptr);
650 }
651 
653  llvm::Value *Ptr, QualType Ty,
654  CharUnits Alignment,
655  SanitizerSet SkippedChecks,
656  llvm::Value *ArraySize) {
658  return;
659 
660  // Don't check pointers outside the default address space. The null check
661  // isn't correct, the object-size check isn't supported by LLVM, and we can't
662  // communicate the addresses to the runtime handler for the vptr check.
663  if (Ptr->getType()->getPointerAddressSpace())
664  return;
665 
666  // Don't check pointers to volatile data. The behavior here is implementation-
667  // defined.
668  if (Ty.isVolatileQualified())
669  return;
670 
671  SanitizerScope SanScope(this);
672 
674  llvm::BasicBlock *Done = nullptr;
675 
676  // Quickly determine whether we have a pointer to an alloca. It's possible
677  // to skip null checks, and some alignment checks, for these pointers. This
678  // can reduce compile-time significantly.
679  auto PtrToAlloca =
680  dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
681 
682  llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
683  llvm::Value *IsNonNull = nullptr;
684  bool IsGuaranteedNonNull =
685  SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
686  bool AllowNullPointers = isNullPointerAllowed(TCK);
687  if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
688  !IsGuaranteedNonNull) {
689  // The glvalue must not be an empty glvalue.
690  IsNonNull = Builder.CreateIsNotNull(Ptr);
691 
692  // The IR builder can constant-fold the null check if the pointer points to
693  // a constant.
694  IsGuaranteedNonNull = IsNonNull == True;
695 
696  // Skip the null check if the pointer is known to be non-null.
697  if (!IsGuaranteedNonNull) {
698  if (AllowNullPointers) {
699  // When performing pointer casts, it's OK if the value is null.
700  // Skip the remaining checks in that case.
701  Done = createBasicBlock("null");
702  llvm::BasicBlock *Rest = createBasicBlock("not.null");
703  Builder.CreateCondBr(IsNonNull, Rest, Done);
704  EmitBlock(Rest);
705  } else {
706  Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
707  }
708  }
709  }
710 
711  if (SanOpts.has(SanitizerKind::ObjectSize) &&
712  !SkippedChecks.has(SanitizerKind::ObjectSize) &&
713  !Ty->isIncompleteType()) {
714  uint64_t TySize = getContext().getTypeSizeInChars(Ty).getQuantity();
715  llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
716  if (ArraySize)
717  Size = Builder.CreateMul(Size, ArraySize);
718 
719  // Degenerate case: new X[0] does not need an objectsize check.
720  llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
721  if (!ConstantSize || !ConstantSize->isNullValue()) {
722  // The glvalue must refer to a large enough storage region.
723  // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
724  // to check this.
725  // FIXME: Get object address space
726  llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
727  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
728  llvm::Value *Min = Builder.getFalse();
729  llvm::Value *NullIsUnknown = Builder.getFalse();
730  llvm::Value *Dynamic = Builder.getFalse();
731  llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
732  llvm::Value *LargeEnough = Builder.CreateICmpUGE(
733  Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
734  Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
735  }
736  }
737 
738  uint64_t AlignVal = 0;
739  llvm::Value *PtrAsInt = nullptr;
740 
741  if (SanOpts.has(SanitizerKind::Alignment) &&
742  !SkippedChecks.has(SanitizerKind::Alignment)) {
743  AlignVal = Alignment.getQuantity();
744  if (!Ty->isIncompleteType() && !AlignVal)
745  AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
746 
747  // The glvalue must be suitably aligned.
748  if (AlignVal > 1 &&
749  (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
750  PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
751  llvm::Value *Align = Builder.CreateAnd(
752  PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
753  llvm::Value *Aligned =
754  Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
755  if (Aligned != True)
756  Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
757  }
758  }
759 
760  if (Checks.size() > 0) {
761  // Make sure we're not losing information. Alignment needs to be a power of
762  // 2
763  assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
764  llvm::Constant *StaticData[] = {
766  llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
767  llvm::ConstantInt::get(Int8Ty, TCK)};
768  EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
769  PtrAsInt ? PtrAsInt : Ptr);
770  }
771 
772  // If possible, check that the vptr indicates that there is a subobject of
773  // type Ty at offset zero within this object.
774  //
775  // C++11 [basic.life]p5,6:
776  // [For storage which does not refer to an object within its lifetime]
777  // The program has undefined behavior if:
778  // -- the [pointer or glvalue] is used to access a non-static data member
779  // or call a non-static member function
780  if (SanOpts.has(SanitizerKind::Vptr) &&
781  !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
782  // Ensure that the pointer is non-null before loading it. If there is no
783  // compile-time guarantee, reuse the run-time null check or emit a new one.
784  if (!IsGuaranteedNonNull) {
785  if (!IsNonNull)
786  IsNonNull = Builder.CreateIsNotNull(Ptr);
787  if (!Done)
788  Done = createBasicBlock("vptr.null");
789  llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
790  Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
791  EmitBlock(VptrNotNull);
792  }
793 
794  // Compute a hash of the mangled name of the type.
795  //
796  // FIXME: This is not guaranteed to be deterministic! Move to a
797  // fingerprinting mechanism once LLVM provides one. For the time
798  // being the implementation happens to be deterministic.
799  SmallString<64> MangledName;
800  llvm::raw_svector_ostream Out(MangledName);
802  Out);
803 
804  // Blacklist based on the mangled type.
806  SanitizerKind::Vptr, Out.str())) {
807  llvm::hash_code TypeHash = hash_value(Out.str());
808 
809  // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
810  llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
811  llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
812  Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
813  llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
814  llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
815 
816  llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
817  Hash = Builder.CreateTrunc(Hash, IntPtrTy);
818 
819  // Look the hash up in our cache.
820  const int CacheSize = 128;
821  llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
823  "__ubsan_vptr_type_cache");
824  llvm::Value *Slot = Builder.CreateAnd(Hash,
825  llvm::ConstantInt::get(IntPtrTy,
826  CacheSize-1));
827  llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
828  llvm::Value *CacheVal =
829  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
830  getPointerAlign());
831 
832  // If the hash isn't in the cache, call a runtime handler to perform the
833  // hard work of checking whether the vptr is for an object of the right
834  // type. This will either fill in the cache and return, or produce a
835  // diagnostic.
836  llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
837  llvm::Constant *StaticData[] = {
841  llvm::ConstantInt::get(Int8Ty, TCK)
842  };
843  llvm::Value *DynamicData[] = { Ptr, Hash };
844  EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
845  SanitizerHandler::DynamicTypeCacheMiss, StaticData,
846  DynamicData);
847  }
848  }
849 
850  if (Done) {
851  Builder.CreateBr(Done);
852  EmitBlock(Done);
853  }
854 }
855 
856 /// Determine whether this expression refers to a flexible array member in a
857 /// struct. We disable array bounds checks for such members.
858 static bool isFlexibleArrayMemberExpr(const Expr *E) {
859  // For compatibility with existing code, we treat arrays of length 0 or
860  // 1 as flexible array members.
861  const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
862  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
863  if (CAT->getSize().ugt(1))
864  return false;
865  } else if (!isa<IncompleteArrayType>(AT))
866  return false;
867 
868  E = E->IgnoreParens();
869 
870  // A flexible array member must be the last member in the class.
871  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
872  // FIXME: If the base type of the member expr is not FD->getParent(),
873  // this should not be treated as a flexible array member access.
874  if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
876  DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
877  return ++FI == FD->getParent()->field_end();
878  }
879  } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
880  return IRE->getDecl()->getNextIvar() == nullptr;
881  }
882 
883  return false;
884 }
885 
887  QualType EltTy) {
888  ASTContext &C = getContext();
889  uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
890  if (!EltSize)
891  return nullptr;
892 
893  auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
894  if (!ArrayDeclRef)
895  return nullptr;
896 
897  auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
898  if (!ParamDecl)
899  return nullptr;
900 
901  auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
902  if (!POSAttr)
903  return nullptr;
904 
905  // Don't load the size if it's a lower bound.
906  int POSType = POSAttr->getType();
907  if (POSType != 0 && POSType != 1)
908  return nullptr;
909 
910  // Find the implicit size parameter.
911  auto PassedSizeIt = SizeArguments.find(ParamDecl);
912  if (PassedSizeIt == SizeArguments.end())
913  return nullptr;
914 
915  const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
916  assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
917  Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
918  llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
919  C.getSizeType(), E->getExprLoc());
920  llvm::Value *SizeOfElement =
921  llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
922  return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
923 }
924 
925 /// If Base is known to point to the start of an array, return the length of
926 /// that array. Return 0 if the length cannot be determined.
928  CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
929  // For the vector indexing extension, the bound is the number of elements.
930  if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
931  IndexedType = Base->getType();
932  return CGF.Builder.getInt32(VT->getNumElements());
933  }
934 
935  Base = Base->IgnoreParens();
936 
937  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
938  if (CE->getCastKind() == CK_ArrayToPointerDecay &&
939  !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
940  IndexedType = CE->getSubExpr()->getType();
941  const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
942  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
943  return CGF.Builder.getInt(CAT->getSize());
944  else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
945  return CGF.getVLASize(VAT).NumElts;
946  // Ignore pass_object_size here. It's not applicable on decayed pointers.
947  }
948  }
949 
950  QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
951  if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
952  IndexedType = Base->getType();
953  return POS;
954  }
955 
956  return nullptr;
957 }
958 
960  llvm::Value *Index, QualType IndexType,
961  bool Accessed) {
962  assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
963  "should not be called unless adding bounds checks");
964  SanitizerScope SanScope(this);
965 
966  QualType IndexedType;
967  llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
968  if (!Bound)
969  return;
970 
971  bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
972  llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
973  llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
974 
975  llvm::Constant *StaticData[] = {
977  EmitCheckTypeDescriptor(IndexedType),
978  EmitCheckTypeDescriptor(IndexType)
979  };
980  llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
981  : Builder.CreateICmpULE(IndexVal, BoundVal);
982  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
983  SanitizerHandler::OutOfBounds, StaticData, Index);
984 }
985 
986 
989  bool isInc, bool isPre) {
990  ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
991 
992  llvm::Value *NextVal;
993  if (isa<llvm::IntegerType>(InVal.first->getType())) {
994  uint64_t AmountVal = isInc ? 1 : -1;
995  NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
996 
997  // Add the inc/dec to the real part.
998  NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
999  } else {
1000  QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
1001  llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1002  if (!isInc)
1003  FVal.changeSign();
1004  NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1005 
1006  // Add the inc/dec to the real part.
1007  NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1008  }
1009 
1010  ComplexPairTy IncVal(NextVal, InVal.second);
1011 
1012  // Store the updated result through the lvalue.
1013  EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1014 
1015  // If this is a postinc, return the value read from memory, otherwise use the
1016  // updated value.
1017  return isPre ? IncVal : InVal;
1018 }
1019 
1021  CodeGenFunction *CGF) {
1022  // Bind VLAs in the cast type.
1023  if (CGF && E->getType()->isVariablyModifiedType())
1024  CGF->EmitVariablyModifiedType(E->getType());
1025 
1026  if (CGDebugInfo *DI = getModuleDebugInfo())
1027  DI->EmitExplicitCastType(E->getType());
1028 }
1029 
1030 //===----------------------------------------------------------------------===//
1031 // LValue Expression Emission
1032 //===----------------------------------------------------------------------===//
1033 
1034 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1035 /// derive a more accurate bound on the alignment of the pointer.
1037  LValueBaseInfo *BaseInfo,
1038  TBAAAccessInfo *TBAAInfo) {
1039  // We allow this with ObjC object pointers because of fragile ABIs.
1040  assert(E->getType()->isPointerType() ||
1042  E = E->IgnoreParens();
1043 
1044  // Casts:
1045  if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1046  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1047  CGM.EmitExplicitCastExprType(ECE, this);
1048 
1049  switch (CE->getCastKind()) {
1050  // Non-converting casts (but not C's implicit conversion from void*).
1051  case CK_BitCast:
1052  case CK_NoOp:
1053  case CK_AddressSpaceConversion:
1054  if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1055  if (PtrTy->getPointeeType()->isVoidType())
1056  break;
1057 
1058  LValueBaseInfo InnerBaseInfo;
1059  TBAAAccessInfo InnerTBAAInfo;
1060  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1061  &InnerBaseInfo,
1062  &InnerTBAAInfo);
1063  if (BaseInfo) *BaseInfo = InnerBaseInfo;
1064  if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1065 
1066  if (isa<ExplicitCastExpr>(CE)) {
1067  LValueBaseInfo TargetTypeBaseInfo;
1068  TBAAAccessInfo TargetTypeTBAAInfo;
1069  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1070  &TargetTypeBaseInfo,
1071  &TargetTypeTBAAInfo);
1072  if (TBAAInfo)
1073  *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1074  TargetTypeTBAAInfo);
1075  // If the source l-value is opaque, honor the alignment of the
1076  // casted-to type.
1077  if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1078  if (BaseInfo)
1079  BaseInfo->mergeForCast(TargetTypeBaseInfo);
1080  Addr = Address(Addr.getPointer(), Align);
1081  }
1082  }
1083 
1084  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1085  CE->getCastKind() == CK_BitCast) {
1086  if (auto PT = E->getType()->getAs<PointerType>())
1087  EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1088  /*MayBeNull=*/true,
1090  CE->getBeginLoc());
1091  }
1092  return CE->getCastKind() != CK_AddressSpaceConversion
1093  ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1095  ConvertType(E->getType()));
1096  }
1097  break;
1098 
1099  // Array-to-pointer decay.
1100  case CK_ArrayToPointerDecay:
1101  return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1102 
1103  // Derived-to-base conversions.
1104  case CK_UncheckedDerivedToBase:
1105  case CK_DerivedToBase: {
1106  // TODO: Support accesses to members of base classes in TBAA. For now, we
1107  // conservatively pretend that the complete object is of the base class
1108  // type.
1109  if (TBAAInfo)
1110  *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1111  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1112  auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1113  return GetAddressOfBaseClass(Addr, Derived,
1114  CE->path_begin(), CE->path_end(),
1116  CE->getExprLoc());
1117  }
1118 
1119  // TODO: Is there any reason to treat base-to-derived conversions
1120  // specially?
1121  default:
1122  break;
1123  }
1124  }
1125 
1126  // Unary &.
1127  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1128  if (UO->getOpcode() == UO_AddrOf) {
1129  LValue LV = EmitLValue(UO->getSubExpr());
1130  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1131  if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1132  return LV.getAddress();
1133  }
1134  }
1135 
1136  // TODO: conditional operators, comma.
1137 
1138  // Otherwise, use the alignment of the type.
1139  CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1140  TBAAInfo);
1141  return Address(EmitScalarExpr(E), Align);
1142 }
1143 
1145  if (Ty->isVoidType())
1146  return RValue::get(nullptr);
1147 
1148  switch (getEvaluationKind(Ty)) {
1149  case TEK_Complex: {
1150  llvm::Type *EltTy =
1152  llvm::Value *U = llvm::UndefValue::get(EltTy);
1153  return RValue::getComplex(std::make_pair(U, U));
1154  }
1155 
1156  // If this is a use of an undefined aggregate type, the aggregate must have an
1157  // identifiable address. Just because the contents of the value are undefined
1158  // doesn't mean that the address can't be taken and compared.
1159  case TEK_Aggregate: {
1160  Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1161  return RValue::getAggregate(DestPtr);
1162  }
1163 
1164  case TEK_Scalar:
1165  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1166  }
1167  llvm_unreachable("bad evaluation kind");
1168 }
1169 
1171  const char *Name) {
1172  ErrorUnsupported(E, Name);
1173  return GetUndefRValue(E->getType());
1174 }
1175 
1177  const char *Name) {
1178  ErrorUnsupported(E, Name);
1179  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1180  return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1181  E->getType());
1182 }
1183 
1185  const Expr *Base = Obj;
1186  while (!isa<CXXThisExpr>(Base)) {
1187  // The result of a dynamic_cast can be null.
1188  if (isa<CXXDynamicCastExpr>(Base))
1189  return false;
1190 
1191  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1192  Base = CE->getSubExpr();
1193  } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1194  Base = PE->getSubExpr();
1195  } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1196  if (UO->getOpcode() == UO_Extension)
1197  Base = UO->getSubExpr();
1198  else
1199  return false;
1200  } else {
1201  return false;
1202  }
1203  }
1204  return true;
1205 }
1206 
1208  LValue LV;
1209  if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1210  LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1211  else
1212  LV = EmitLValue(E);
1213  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1214  SanitizerSet SkippedChecks;
1215  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1216  bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1217  if (IsBaseCXXThis)
1218  SkippedChecks.set(SanitizerKind::Alignment, true);
1219  if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1220  SkippedChecks.set(SanitizerKind::Null, true);
1221  }
1222  EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1223  E->getType(), LV.getAlignment(), SkippedChecks);
1224  }
1225  return LV;
1226 }
1227 
1228 /// EmitLValue - Emit code to compute a designator that specifies the location
1229 /// of the expression.
1230 ///
1231 /// This can return one of two things: a simple address or a bitfield reference.
1232 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1233 /// an LLVM pointer type.
1234 ///
1235 /// If this returns a bitfield reference, nothing about the pointee type of the
1236 /// LLVM value is known: For example, it may not be a pointer to an integer.
1237 ///
1238 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1239 /// this method guarantees that the returned pointer type will point to an LLVM
1240 /// type of the same size of the lvalue's type. If the lvalue has a variable
1241 /// length type, this is not possible.
1242 ///
1244  ApplyDebugLocation DL(*this, E);
1245  switch (E->getStmtClass()) {
1246  default: return EmitUnsupportedLValue(E, "l-value expression");
1247 
1248  case Expr::ObjCPropertyRefExprClass:
1249  llvm_unreachable("cannot emit a property reference directly");
1250 
1251  case Expr::ObjCSelectorExprClass:
1252  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1253  case Expr::ObjCIsaExprClass:
1254  return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1255  case Expr::BinaryOperatorClass:
1256  return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1257  case Expr::CompoundAssignOperatorClass: {
1258  QualType Ty = E->getType();
1259  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1260  Ty = AT->getValueType();
1261  if (!Ty->isAnyComplexType())
1262  return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1263  return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1264  }
1265  case Expr::CallExprClass:
1266  case Expr::CXXMemberCallExprClass:
1267  case Expr::CXXOperatorCallExprClass:
1268  case Expr::UserDefinedLiteralClass:
1269  return EmitCallExprLValue(cast<CallExpr>(E));
1270  case Expr::VAArgExprClass:
1271  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1272  case Expr::DeclRefExprClass:
1273  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1274  case Expr::ConstantExprClass:
1275  return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1276  case Expr::ParenExprClass:
1277  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1278  case Expr::GenericSelectionExprClass:
1279  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1280  case Expr::PredefinedExprClass:
1281  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1282  case Expr::StringLiteralClass:
1283  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1284  case Expr::ObjCEncodeExprClass:
1285  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1286  case Expr::PseudoObjectExprClass:
1287  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1288  case Expr::InitListExprClass:
1289  return EmitInitListLValue(cast<InitListExpr>(E));
1290  case Expr::CXXTemporaryObjectExprClass:
1291  case Expr::CXXConstructExprClass:
1292  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1293  case Expr::CXXBindTemporaryExprClass:
1294  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1295  case Expr::CXXUuidofExprClass:
1296  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1297 
1298  case Expr::ExprWithCleanupsClass: {
1299  const auto *cleanups = cast<ExprWithCleanups>(E);
1300  enterFullExpression(cleanups);
1301  RunCleanupsScope Scope(*this);
1302  LValue LV = EmitLValue(cleanups->getSubExpr());
1303  if (LV.isSimple()) {
1304  // Defend against branches out of gnu statement expressions surrounded by
1305  // cleanups.
1306  llvm::Value *V = LV.getPointer();
1307  Scope.ForceCleanup({&V});
1308  return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1309  getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1310  }
1311  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1312  // bitfield lvalue or some other non-simple lvalue?
1313  return LV;
1314  }
1315 
1316  case Expr::CXXDefaultArgExprClass:
1317  return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1318  case Expr::CXXDefaultInitExprClass: {
1320  return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1321  }
1322  case Expr::CXXTypeidExprClass:
1323  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1324 
1325  case Expr::ObjCMessageExprClass:
1326  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1327  case Expr::ObjCIvarRefExprClass:
1328  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1329  case Expr::StmtExprClass:
1330  return EmitStmtExprLValue(cast<StmtExpr>(E));
1331  case Expr::UnaryOperatorClass:
1332  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1333  case Expr::ArraySubscriptExprClass:
1334  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1335  case Expr::OMPArraySectionExprClass:
1336  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1337  case Expr::ExtVectorElementExprClass:
1338  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1339  case Expr::MemberExprClass:
1340  return EmitMemberExpr(cast<MemberExpr>(E));
1341  case Expr::CompoundLiteralExprClass:
1342  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1343  case Expr::ConditionalOperatorClass:
1344  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1345  case Expr::BinaryConditionalOperatorClass:
1346  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1347  case Expr::ChooseExprClass:
1348  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1349  case Expr::OpaqueValueExprClass:
1350  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1351  case Expr::SubstNonTypeTemplateParmExprClass:
1352  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1353  case Expr::ImplicitCastExprClass:
1354  case Expr::CStyleCastExprClass:
1355  case Expr::CXXFunctionalCastExprClass:
1356  case Expr::CXXStaticCastExprClass:
1357  case Expr::CXXDynamicCastExprClass:
1358  case Expr::CXXReinterpretCastExprClass:
1359  case Expr::CXXConstCastExprClass:
1360  case Expr::ObjCBridgedCastExprClass:
1361  return EmitCastLValue(cast<CastExpr>(E));
1362 
1363  case Expr::MaterializeTemporaryExprClass:
1364  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1365 
1366  case Expr::CoawaitExprClass:
1367  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1368  case Expr::CoyieldExprClass:
1369  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1370  }
1371 }
1372 
1373 /// Given an object of the given canonical type, can we safely copy a
1374 /// value out of it based on its initializer?
1376  assert(type.isCanonical());
1377  assert(!type->isReferenceType());
1378 
1379  // Must be const-qualified but non-volatile.
1380  Qualifiers qs = type.getLocalQualifiers();
1381  if (!qs.hasConst() || qs.hasVolatile()) return false;
1382 
1383  // Otherwise, all object types satisfy this except C++ classes with
1384  // mutable subobjects or non-trivial copy/destroy behavior.
1385  if (const auto *RT = dyn_cast<RecordType>(type))
1386  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1387  if (RD->hasMutableFields() || !RD->isTrivial())
1388  return false;
1389 
1390  return true;
1391 }
1392 
1393 /// Can we constant-emit a load of a reference to a variable of the
1394 /// given type? This is different from predicates like
1395 /// Decl::isUsableInConstantExpressions because we do want it to apply
1396 /// in situations that don't necessarily satisfy the language's rules
1397 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1398 /// to do this with const float variables even if those variables
1399 /// aren't marked 'constexpr'.
1405 };
1407  type = type.getCanonicalType();
1408  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1409  if (isConstantEmittableObjectType(ref->getPointeeType()))
1410  return CEK_AsValueOrReference;
1411  return CEK_AsReferenceOnly;
1412  }
1414  return CEK_AsValueOnly;
1415  return CEK_None;
1416 }
1417 
1418 /// Try to emit a reference to the given value without producing it as
1419 /// an l-value. This is actually more than an optimization: we can't
1420 /// produce an l-value for variables that we never actually captured
1421 /// in a block or lambda, which means const int variables or constexpr
1422 /// literals or similar.
1425  ValueDecl *value = refExpr->getDecl();
1426 
1427  // The value needs to be an enum constant or a constant variable.
1429  if (isa<ParmVarDecl>(value)) {
1430  CEK = CEK_None;
1431  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1432  CEK = checkVarTypeForConstantEmission(var->getType());
1433  } else if (isa<EnumConstantDecl>(value)) {
1434  CEK = CEK_AsValueOnly;
1435  } else {
1436  CEK = CEK_None;
1437  }
1438  if (CEK == CEK_None) return ConstantEmission();
1439 
1440  Expr::EvalResult result;
1441  bool resultIsReference;
1442  QualType resultType;
1443 
1444  // It's best to evaluate all the way as an r-value if that's permitted.
1445  if (CEK != CEK_AsReferenceOnly &&
1446  refExpr->EvaluateAsRValue(result, getContext())) {
1447  resultIsReference = false;
1448  resultType = refExpr->getType();
1449 
1450  // Otherwise, try to evaluate as an l-value.
1451  } else if (CEK != CEK_AsValueOnly &&
1452  refExpr->EvaluateAsLValue(result, getContext())) {
1453  resultIsReference = true;
1454  resultType = value->getType();
1455 
1456  // Failure.
1457  } else {
1458  return ConstantEmission();
1459  }
1460 
1461  // In any case, if the initializer has side-effects, abandon ship.
1462  if (result.HasSideEffects)
1463  return ConstantEmission();
1464 
1465  // Emit as a constant.
1466  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1467  result.Val, resultType);
1468 
1469  // Make sure we emit a debug reference to the global variable.
1470  // This should probably fire even for
1471  if (isa<VarDecl>(value)) {
1472  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1473  EmitDeclRefExprDbgValue(refExpr, result.Val);
1474  } else {
1475  assert(isa<EnumConstantDecl>(value));
1476  EmitDeclRefExprDbgValue(refExpr, result.Val);
1477  }
1478 
1479  // If we emitted a reference constant, we need to dereference that.
1480  if (resultIsReference)
1482 
1483  return ConstantEmission::forValue(C);
1484 }
1485 
1487  const MemberExpr *ME) {
1488  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1489  // Try to emit static variable member expressions as DREs.
1490  return DeclRefExpr::Create(
1492  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1493  ME->getType(), ME->getValueKind());
1494  }
1495  return nullptr;
1496 }
1497 
1500  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1501  return tryEmitAsConstant(DRE);
1502  return ConstantEmission();
1503 }
1504 
1506  const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1507  assert(Constant && "not a constant");
1508  if (Constant.isReference())
1509  return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1510  E->getExprLoc())
1511  .getScalarVal();
1512  return Constant.getValue();
1513 }
1514 
1516  SourceLocation Loc) {
1517  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1518  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1519  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1520 }
1521 
1523  if (Ty->isBooleanType())
1524  return true;
1525 
1526  if (const EnumType *ET = Ty->getAs<EnumType>())
1527  return ET->getDecl()->getIntegerType()->isBooleanType();
1528 
1529  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1530  return hasBooleanRepresentation(AT->getValueType());
1531 
1532  return false;
1533 }
1534 
1536  llvm::APInt &Min, llvm::APInt &End,
1537  bool StrictEnums, bool IsBool) {
1538  const EnumType *ET = Ty->getAs<EnumType>();
1539  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1540  ET && !ET->getDecl()->isFixed();
1541  if (!IsBool && !IsRegularCPlusPlusEnum)
1542  return false;
1543 
1544  if (IsBool) {
1545  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1546  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1547  } else {
1548  const EnumDecl *ED = ET->getDecl();
1549  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1550  unsigned Bitwidth = LTy->getScalarSizeInBits();
1551  unsigned NumNegativeBits = ED->getNumNegativeBits();
1552  unsigned NumPositiveBits = ED->getNumPositiveBits();
1553 
1554  if (NumNegativeBits) {
1555  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1556  assert(NumBits <= Bitwidth);
1557  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1558  Min = -End;
1559  } else {
1560  assert(NumPositiveBits <= Bitwidth);
1561  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1562  Min = llvm::APInt(Bitwidth, 0);
1563  }
1564  }
1565  return true;
1566 }
1567 
1568 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1569  llvm::APInt Min, End;
1570  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1572  return nullptr;
1573 
1574  llvm::MDBuilder MDHelper(getLLVMContext());
1575  return MDHelper.createRange(Min, End);
1576 }
1577 
1579  SourceLocation Loc) {
1580  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1581  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1582  if (!HasBoolCheck && !HasEnumCheck)
1583  return false;
1584 
1585  bool IsBool = hasBooleanRepresentation(Ty) ||
1586  NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1587  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1588  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1589  if (!NeedsBoolCheck && !NeedsEnumCheck)
1590  return false;
1591 
1592  // Single-bit booleans don't need to be checked. Special-case this to avoid
1593  // a bit width mismatch when handling bitfield values. This is handled by
1594  // EmitFromMemory for the non-bitfield case.
1595  if (IsBool &&
1596  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1597  return false;
1598 
1599  llvm::APInt Min, End;
1600  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1601  return true;
1602 
1603  auto &Ctx = getLLVMContext();
1604  SanitizerScope SanScope(this);
1605  llvm::Value *Check;
1606  --End;
1607  if (!Min) {
1608  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1609  } else {
1610  llvm::Value *Upper =
1611  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1612  llvm::Value *Lower =
1613  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1614  Check = Builder.CreateAnd(Upper, Lower);
1615  }
1616  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1619  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1620  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1621  StaticArgs, EmitCheckValue(Value));
1622  return true;
1623 }
1624 
1626  QualType Ty,
1627  SourceLocation Loc,
1628  LValueBaseInfo BaseInfo,
1629  TBAAAccessInfo TBAAInfo,
1630  bool isNontemporal) {
1631  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1632  // For better performance, handle vector loads differently.
1633  if (Ty->isVectorType()) {
1634  const llvm::Type *EltTy = Addr.getElementType();
1635 
1636  const auto *VTy = cast<llvm::VectorType>(EltTy);
1637 
1638  // Handle vectors of size 3 like size 4 for better performance.
1639  if (VTy->getNumElements() == 3) {
1640 
1641  // Bitcast to vec4 type.
1642  llvm::VectorType *vec4Ty =
1643  llvm::VectorType::get(VTy->getElementType(), 4);
1644  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1645  // Now load value.
1646  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1647 
1648  // Shuffle vector to get vec3.
1649  V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1650  {0, 1, 2}, "extractVec");
1651  return EmitFromMemory(V, Ty);
1652  }
1653  }
1654  }
1655 
1656  // Atomic operations have to be done on integral types.
1657  LValue AtomicLValue =
1658  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1659  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1660  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1661  }
1662 
1663  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1664  if (isNontemporal) {
1665  llvm::MDNode *Node = llvm::MDNode::get(
1666  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1667  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1668  }
1669 
1670  CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1671 
1672  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1673  // In order to prevent the optimizer from throwing away the check, don't
1674  // attach range metadata to the load.
1675  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1676  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1677  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1678 
1679  return EmitFromMemory(Load, Ty);
1680 }
1681 
1683  // Bool has a different representation in memory than in registers.
1684  if (hasBooleanRepresentation(Ty)) {
1685  // This should really always be an i1, but sometimes it's already
1686  // an i8, and it's awkward to track those cases down.
1687  if (Value->getType()->isIntegerTy(1))
1688  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1689  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1690  "wrong value rep of bool");
1691  }
1692 
1693  return Value;
1694 }
1695 
1697  // Bool has a different representation in memory than in registers.
1698  if (hasBooleanRepresentation(Ty)) {
1699  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1700  "wrong value rep of bool");
1701  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1702  }
1703 
1704  return Value;
1705 }
1706 
1708  bool Volatile, QualType Ty,
1709  LValueBaseInfo BaseInfo,
1710  TBAAAccessInfo TBAAInfo,
1711  bool isInit, bool isNontemporal) {
1712  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1713  // Handle vectors differently to get better performance.
1714  if (Ty->isVectorType()) {
1715  llvm::Type *SrcTy = Value->getType();
1716  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1717  // Handle vec3 special.
1718  if (VecTy && VecTy->getNumElements() == 3) {
1719  // Our source is a vec3, do a shuffle vector to make it a vec4.
1720  llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1721  Builder.getInt32(2),
1722  llvm::UndefValue::get(Builder.getInt32Ty())};
1723  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1724  Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1725  MaskV, "extractVec");
1726  SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1727  }
1728  if (Addr.getElementType() != SrcTy) {
1729  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1730  }
1731  }
1732  }
1733 
1734  Value = EmitToMemory(Value, Ty);
1735 
1736  LValue AtomicLValue =
1737  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1738  if (Ty->isAtomicType() ||
1739  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1740  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1741  return;
1742  }
1743 
1744  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1745  if (isNontemporal) {
1746  llvm::MDNode *Node =
1747  llvm::MDNode::get(Store->getContext(),
1748  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1749  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1750  }
1751 
1752  CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1753 }
1754 
1756  bool isInit) {
1757  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1758  lvalue.getType(), lvalue.getBaseInfo(),
1759  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1760 }
1761 
1762 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1763 /// method emits the address of the lvalue, then loads the result as an rvalue,
1764 /// returning the rvalue.
1766  if (LV.isObjCWeak()) {
1767  // load of a __weak object.
1768  Address AddrWeakObj = LV.getAddress();
1770  AddrWeakObj));
1771  }
1773  // In MRC mode, we do a load+autorelease.
1774  if (!getLangOpts().ObjCAutoRefCount) {
1775  return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1776  }
1777 
1778  // In ARC mode, we load retained and then consume the value.
1780  Object = EmitObjCConsumeObject(LV.getType(), Object);
1781  return RValue::get(Object);
1782  }
1783 
1784  if (LV.isSimple()) {
1785  assert(!LV.getType()->isFunctionType());
1786 
1787  // Everything needs a load.
1788  return RValue::get(EmitLoadOfScalar(LV, Loc));
1789  }
1790 
1791  if (LV.isVectorElt()) {
1792  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1793  LV.isVolatileQualified());
1794  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1795  "vecext"));
1796  }
1797 
1798  // If this is a reference to a subset of the elements of a vector, either
1799  // shuffle the input or extract/insert them as appropriate.
1800  if (LV.isExtVectorElt())
1802 
1803  // Global Register variables always invoke intrinsics
1804  if (LV.isGlobalReg())
1805  return EmitLoadOfGlobalRegLValue(LV);
1806 
1807  assert(LV.isBitField() && "Unknown LValue type!");
1808  return EmitLoadOfBitfieldLValue(LV, Loc);
1809 }
1810 
1812  SourceLocation Loc) {
1813  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1814 
1815  // Get the output type.
1816  llvm::Type *ResLTy = ConvertType(LV.getType());
1817 
1818  Address Ptr = LV.getBitFieldAddress();
1819  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1820 
1821  if (Info.IsSigned) {
1822  assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1823  unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1824  if (HighBits)
1825  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1826  if (Info.Offset + HighBits)
1827  Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1828  } else {
1829  if (Info.Offset)
1830  Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1831  if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1832  Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1833  Info.Size),
1834  "bf.clear");
1835  }
1836  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1837  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1838  return RValue::get(Val);
1839 }
1840 
1841 // If this is a reference to a subset of the elements of a vector, create an
1842 // appropriate shufflevector.
1845  LV.isVolatileQualified());
1846 
1847  const llvm::Constant *Elts = LV.getExtVectorElts();
1848 
1849  // If the result of the expression is a non-vector type, we must be extracting
1850  // a single element. Just codegen as an extractelement.
1851  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1852  if (!ExprVT) {
1853  unsigned InIdx = getAccessedFieldNo(0, Elts);
1854  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1855  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1856  }
1857 
1858  // Always use shuffle vector to try to retain the original program structure
1859  unsigned NumResultElts = ExprVT->getNumElements();
1860 
1862  for (unsigned i = 0; i != NumResultElts; ++i)
1863  Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1864 
1865  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1866  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1867  MaskV);
1868  return RValue::get(Vec);
1869 }
1870 
1871 /// Generates lvalue for partial ext_vector access.
1873  Address VectorAddress = LV.getExtVectorAddress();
1874  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1875  QualType EQT = ExprVT->getElementType();
1876  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1877 
1878  Address CastToPointerElement =
1879  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1880  "conv.ptr.element");
1881 
1882  const llvm::Constant *Elts = LV.getExtVectorElts();
1883  unsigned ix = getAccessedFieldNo(0, Elts);
1884 
1885  Address VectorBasePtrPlusIx =
1886  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1887  "vector.elt");
1888 
1889  return VectorBasePtrPlusIx;
1890 }
1891 
1892 /// Load of global gamed gegisters are always calls to intrinsics.
1894  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1895  "Bad type for register variable");
1896  llvm::MDNode *RegName = cast<llvm::MDNode>(
1897  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1898 
1899  // We accept integer and pointer types only
1900  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1901  llvm::Type *Ty = OrigTy;
1902  if (OrigTy->isPointerTy())
1903  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1904  llvm::Type *Types[] = { Ty };
1905 
1906  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1907  llvm::Value *Call = Builder.CreateCall(
1908  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1909  if (OrigTy->isPointerTy())
1910  Call = Builder.CreateIntToPtr(Call, OrigTy);
1911  return RValue::get(Call);
1912 }
1913 
1914 
1915 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1916 /// lvalue, where both are guaranteed to the have the same type, and that type
1917 /// is 'Ty'.
1919  bool isInit) {
1920  if (!Dst.isSimple()) {
1921  if (Dst.isVectorElt()) {
1922  // Read/modify/write the vector, inserting the new element.
1924  Dst.isVolatileQualified());
1925  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1926  Dst.getVectorIdx(), "vecins");
1928  Dst.isVolatileQualified());
1929  return;
1930  }
1931 
1932  // If this is an update of extended vector elements, insert them as
1933  // appropriate.
1934  if (Dst.isExtVectorElt())
1936 
1937  if (Dst.isGlobalReg())
1938  return EmitStoreThroughGlobalRegLValue(Src, Dst);
1939 
1940  assert(Dst.isBitField() && "Unknown LValue type");
1941  return EmitStoreThroughBitfieldLValue(Src, Dst);
1942  }
1943 
1944  // There's special magic for assigning into an ARC-qualified l-value.
1945  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1946  switch (Lifetime) {
1947  case Qualifiers::OCL_None:
1948  llvm_unreachable("present but none");
1949 
1951  // nothing special
1952  break;
1953 
1955  if (isInit) {
1956  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1957  break;
1958  }
1959  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1960  return;
1961 
1962  case Qualifiers::OCL_Weak:
1963  if (isInit)
1964  // Initialize and then skip the primitive store.
1965  EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1966  else
1967  EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1968  return;
1969 
1972  Src.getScalarVal()));
1973  // fall into the normal path
1974  break;
1975  }
1976  }
1977 
1978  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1979  // load of a __weak object.
1980  Address LvalueDst = Dst.getAddress();
1981  llvm::Value *src = Src.getScalarVal();
1982  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1983  return;
1984  }
1985 
1986  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1987  // load of a __strong object.
1988  Address LvalueDst = Dst.getAddress();
1989  llvm::Value *src = Src.getScalarVal();
1990  if (Dst.isObjCIvar()) {
1991  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1992  llvm::Type *ResultType = IntPtrTy;
1994  llvm::Value *RHS = dst.getPointer();
1995  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1996  llvm::Value *LHS =
1997  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1998  "sub.ptr.lhs.cast");
1999  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2000  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2001  BytesBetween);
2002  } else if (Dst.isGlobalObjCRef()) {
2003  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2004  Dst.isThreadLocalRef());
2005  }
2006  else
2007  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2008  return;
2009  }
2010 
2011  assert(Src.isScalar() && "Can't emit an agg store with this method");
2012  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2013 }
2014 
2016  llvm::Value **Result) {
2017  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2018  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2019  Address Ptr = Dst.getBitFieldAddress();
2020 
2021  // Get the source value, truncated to the width of the bit-field.
2022  llvm::Value *SrcVal = Src.getScalarVal();
2023 
2024  // Cast the source to the storage type and shift it into place.
2025  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2026  /*IsSigned=*/false);
2027  llvm::Value *MaskedVal = SrcVal;
2028 
2029  // See if there are other bits in the bitfield's storage we'll need to load
2030  // and mask together with source before storing.
2031  if (Info.StorageSize != Info.Size) {
2032  assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
2033  llvm::Value *Val =
2034  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2035 
2036  // Mask the source value as needed.
2037  if (!hasBooleanRepresentation(Dst.getType()))
2038  SrcVal = Builder.CreateAnd(SrcVal,
2039  llvm::APInt::getLowBitsSet(Info.StorageSize,
2040  Info.Size),
2041  "bf.value");
2042  MaskedVal = SrcVal;
2043  if (Info.Offset)
2044  SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
2045 
2046  // Mask out the original value.
2047  Val = Builder.CreateAnd(Val,
2048  ~llvm::APInt::getBitsSet(Info.StorageSize,
2049  Info.Offset,
2050  Info.Offset + Info.Size),
2051  "bf.clear");
2052 
2053  // Or together the unchanged values and the source value.
2054  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2055  } else {
2056  assert(Info.Offset == 0);
2057  }
2058 
2059  // Write the new value back out.
2060  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2061 
2062  // Return the new value of the bit-field, if requested.
2063  if (Result) {
2064  llvm::Value *ResultVal = MaskedVal;
2065 
2066  // Sign extend the value if needed.
2067  if (Info.IsSigned) {
2068  assert(Info.Size <= Info.StorageSize);
2069  unsigned HighBits = Info.StorageSize - Info.Size;
2070  if (HighBits) {
2071  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2072  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2073  }
2074  }
2075 
2076  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2077  "bf.result.cast");
2078  *Result = EmitFromMemory(ResultVal, Dst.getType());
2079  }
2080 }
2081 
2083  LValue Dst) {
2084  // This access turns into a read/modify/write of the vector. Load the input
2085  // value now.
2087  Dst.isVolatileQualified());
2088  const llvm::Constant *Elts = Dst.getExtVectorElts();
2089 
2090  llvm::Value *SrcVal = Src.getScalarVal();
2091 
2092  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2093  unsigned NumSrcElts = VTy->getNumElements();
2094  unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2095  if (NumDstElts == NumSrcElts) {
2096  // Use shuffle vector is the src and destination are the same number of
2097  // elements and restore the vector mask since it is on the side it will be
2098  // stored.
2099  SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2100  for (unsigned i = 0; i != NumSrcElts; ++i)
2101  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2102 
2103  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2104  Vec = Builder.CreateShuffleVector(SrcVal,
2105  llvm::UndefValue::get(Vec->getType()),
2106  MaskV);
2107  } else if (NumDstElts > NumSrcElts) {
2108  // Extended the source vector to the same length and then shuffle it
2109  // into the destination.
2110  // FIXME: since we're shuffling with undef, can we just use the indices
2111  // into that? This could be simpler.
2113  for (unsigned i = 0; i != NumSrcElts; ++i)
2114  ExtMask.push_back(Builder.getInt32(i));
2115  ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2116  llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2117  llvm::Value *ExtSrcVal =
2118  Builder.CreateShuffleVector(SrcVal,
2119  llvm::UndefValue::get(SrcVal->getType()),
2120  ExtMaskV);
2121  // build identity
2123  for (unsigned i = 0; i != NumDstElts; ++i)
2124  Mask.push_back(Builder.getInt32(i));
2125 
2126  // When the vector size is odd and .odd or .hi is used, the last element
2127  // of the Elts constant array will be one past the size of the vector.
2128  // Ignore the last element here, if it is greater than the mask size.
2129  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2130  NumSrcElts--;
2131 
2132  // modify when what gets shuffled in
2133  for (unsigned i = 0; i != NumSrcElts; ++i)
2134  Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2135  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2136  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2137  } else {
2138  // We should never shorten the vector
2139  llvm_unreachable("unexpected shorten vector length");
2140  }
2141  } else {
2142  // If the Src is a scalar (not a vector) it must be updating one element.
2143  unsigned InIdx = getAccessedFieldNo(0, Elts);
2144  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2145  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2146  }
2147 
2149  Dst.isVolatileQualified());
2150 }
2151 
2152 /// Store of global named registers are always calls to intrinsics.
2154  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2155  "Bad type for register variable");
2156  llvm::MDNode *RegName = cast<llvm::MDNode>(
2157  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2158  assert(RegName && "Register LValue is not metadata");
2159 
2160  // We accept integer and pointer types only
2161  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2162  llvm::Type *Ty = OrigTy;
2163  if (OrigTy->isPointerTy())
2164  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2165  llvm::Type *Types[] = { Ty };
2166 
2167  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2168  llvm::Value *Value = Src.getScalarVal();
2169  if (OrigTy->isPointerTy())
2170  Value = Builder.CreatePtrToInt(Value, Ty);
2171  Builder.CreateCall(
2172  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2173 }
2174 
2175 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2176 // generating write-barries API. It is currently a global, ivar,
2177 // or neither.
2178 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2179  LValue &LV,
2180  bool IsMemberAccess=false) {
2181  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2182  return;
2183 
2184  if (isa<ObjCIvarRefExpr>(E)) {
2185  QualType ExpTy = E->getType();
2186  if (IsMemberAccess && ExpTy->isPointerType()) {
2187  // If ivar is a structure pointer, assigning to field of
2188  // this struct follows gcc's behavior and makes it a non-ivar
2189  // writer-barrier conservatively.
2190  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2191  if (ExpTy->isRecordType()) {
2192  LV.setObjCIvar(false);
2193  return;
2194  }
2195  }
2196  LV.setObjCIvar(true);
2197  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2198  LV.setBaseIvarExp(Exp->getBase());
2199  LV.setObjCArray(E->getType()->isArrayType());
2200  return;
2201  }
2202 
2203  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2204  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2205  if (VD->hasGlobalStorage()) {
2206  LV.setGlobalObjCRef(true);
2207  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2208  }
2209  }
2210  LV.setObjCArray(E->getType()->isArrayType());
2211  return;
2212  }
2213 
2214  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2215  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2216  return;
2217  }
2218 
2219  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2220  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2221  if (LV.isObjCIvar()) {
2222  // If cast is to a structure pointer, follow gcc's behavior and make it
2223  // a non-ivar write-barrier.
2224  QualType ExpTy = E->getType();
2225  if (ExpTy->isPointerType())
2226  ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2227  if (ExpTy->isRecordType())
2228  LV.setObjCIvar(false);
2229  }
2230  return;
2231  }
2232 
2233  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2234  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2235  return;
2236  }
2237 
2238  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2239  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2240  return;
2241  }
2242 
2243  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2244  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2245  return;
2246  }
2247 
2248  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2249  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2250  return;
2251  }
2252 
2253  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2254  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2255  if (LV.isObjCIvar() && !LV.isObjCArray())
2256  // Using array syntax to assigning to what an ivar points to is not
2257  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2258  LV.setObjCIvar(false);
2259  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2260  // Using array syntax to assigning to what global points to is not
2261  // same as assigning to the global itself. {id *G;} G[i] = 0;
2262  LV.setGlobalObjCRef(false);
2263  return;
2264  }
2265 
2266  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2267  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2268  // We don't know if member is an 'ivar', but this flag is looked at
2269  // only in the context of LV.isObjCIvar().
2270  LV.setObjCArray(E->getType()->isArrayType());
2271  return;
2272  }
2273 }
2274 
2275 static llvm::Value *
2277  llvm::Value *V, llvm::Type *IRType,
2278  StringRef Name = StringRef()) {
2279  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2280  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2281 }
2282 
2284  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2285  llvm::Type *RealVarTy, SourceLocation Loc) {
2286  Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2287  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2288  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2289 }
2290 
2292  const VarDecl *VD, QualType T) {
2294  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2295  if (!Res || *Res == OMPDeclareTargetDeclAttr::MT_To)
2296  return Address::invalid();
2297  assert(*Res == OMPDeclareTargetDeclAttr::MT_Link && "Expected link clause");
2298  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2299  Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
2300  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2301 }
2302 
2303 Address
2305  LValueBaseInfo *PointeeBaseInfo,
2306  TBAAAccessInfo *PointeeTBAAInfo) {
2307  llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2308  RefLVal.isVolatile());
2309  CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2310 
2312  PointeeBaseInfo, PointeeTBAAInfo,
2313  /* forPointeeType= */ true);
2314  return Address(Load, Align);
2315 }
2316 
2318  LValueBaseInfo PointeeBaseInfo;
2319  TBAAAccessInfo PointeeTBAAInfo;
2320  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2321  &PointeeTBAAInfo);
2322  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2323  PointeeBaseInfo, PointeeTBAAInfo);
2324 }
2325 
2327  const PointerType *PtrTy,
2328  LValueBaseInfo *BaseInfo,
2329  TBAAAccessInfo *TBAAInfo) {
2330  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2331  return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2332  BaseInfo, TBAAInfo,
2333  /*forPointeeType=*/true));
2334 }
2335 
2337  const PointerType *PtrTy) {
2338  LValueBaseInfo BaseInfo;
2339  TBAAAccessInfo TBAAInfo;
2340  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2341  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2342 }
2343 
2345  const Expr *E, const VarDecl *VD) {
2346  QualType T = E->getType();
2347 
2348  // If it's thread_local, emit a call to its wrapper function instead.
2349  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2351  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2352  // Check if the variable is marked as declare target with link clause in
2353  // device codegen.
2354  if (CGF.getLangOpts().OpenMPIsDevice) {
2355  Address Addr = emitDeclTargetLinkVarDeclLValue(CGF, VD, T);
2356  if (Addr.isValid())
2357  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2358  }
2359 
2360  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2361  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2362  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2363  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2364  Address Addr(V, Alignment);
2365  // Emit reference to the private copy of the variable if it is an OpenMP
2366  // threadprivate variable.
2367  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2368  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2369  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2370  E->getExprLoc());
2371  }
2372  LValue LV = VD->getType()->isReferenceType() ?
2373  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2375  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2376  setObjCGCLValueClass(CGF.getContext(), E, LV);
2377  return LV;
2378 }
2379 
2381  const FunctionDecl *FD) {
2382  if (FD->hasAttr<WeakRefAttr>()) {
2383  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2384  return aliasee.getPointer();
2385  }
2386 
2387  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2388  if (!FD->hasPrototype()) {
2389  if (const FunctionProtoType *Proto =
2390  FD->getType()->getAs<FunctionProtoType>()) {
2391  // Ugly case: for a K&R-style definition, the type of the definition
2392  // isn't the same as the type of a use. Correct for this with a
2393  // bitcast.
2394  QualType NoProtoType =
2395  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2396  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2397  V = llvm::ConstantExpr::getBitCast(V,
2398  CGM.getTypes().ConvertType(NoProtoType));
2399  }
2400  }
2401  return V;
2402 }
2403 
2405  const Expr *E, const FunctionDecl *FD) {
2406  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2407  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2408  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2410 }
2411 
2413  llvm::Value *ThisValue) {
2415  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2416  return CGF.EmitLValueForField(LV, FD);
2417 }
2418 
2419 /// Named Registers are named metadata pointing to the register name
2420 /// which will be read from/written to as an argument to the intrinsic
2421 /// @llvm.read/write_register.
2422 /// So far, only the name is being passed down, but other options such as
2423 /// register type, allocation type or even optimization options could be
2424 /// passed down via the metadata node.
2426  SmallString<64> Name("llvm.named.register.");
2427  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2428  assert(Asm->getLabel().size() < 64-Name.size() &&
2429  "Register name too big");
2430  Name.append(Asm->getLabel());
2431  llvm::NamedMDNode *M =
2432  CGM.getModule().getOrInsertNamedMetadata(Name);
2433  if (M->getNumOperands() == 0) {
2434  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2435  Asm->getLabel());
2436  llvm::Metadata *Ops[] = {Str};
2437  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2438  }
2439 
2440  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2441 
2442  llvm::Value *Ptr =
2443  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2444  return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2445 }
2446 
2448  const NamedDecl *ND = E->getDecl();
2449  QualType T = E->getType();
2450 
2451  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2452  // Global Named registers access via intrinsics only
2453  if (VD->getStorageClass() == SC_Register &&
2454  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2455  return EmitGlobalNamedRegister(VD, CGM);
2456 
2457  // A DeclRefExpr for a reference initialized by a constant expression can
2458  // appear without being odr-used. Directly emit the constant initializer.
2459  const Expr *Init = VD->getAnyInitializer(VD);
2460  const auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl);
2461  if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2462  VD->isUsableInConstantExpressions(getContext()) &&
2463  VD->checkInitIsICE() &&
2464  // Do not emit if it is private OpenMP variable.
2466  ((CapturedStmtInfo &&
2467  (LocalDeclMap.count(VD->getCanonicalDecl()) ||
2468  CapturedStmtInfo->lookup(VD->getCanonicalDecl()))) ||
2469  LambdaCaptureFields.lookup(VD->getCanonicalDecl()) ||
2470  (BD && BD->capturesVariable(VD))))) {
2471  llvm::Constant *Val =
2473  *VD->evaluateValue(),
2474  VD->getType());
2475  assert(Val && "failed to emit reference constant expression");
2476  // FIXME: Eventually we will want to emit vector element references.
2477 
2478  // Should we be using the alignment of the constant pointer we emitted?
2479  CharUnits Alignment = getNaturalTypeAlignment(E->getType(),
2480  /* BaseInfo= */ nullptr,
2481  /* TBAAInfo= */ nullptr,
2482  /* forPointeeType= */ true);
2483  return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2484  }
2485 
2486  // Check for captured variables.
2488  VD = VD->getCanonicalDecl();
2489  if (auto *FD = LambdaCaptureFields.lookup(VD))
2490  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2491  else if (CapturedStmtInfo) {
2492  auto I = LocalDeclMap.find(VD);
2493  if (I != LocalDeclMap.end()) {
2494  if (VD->getType()->isReferenceType())
2495  return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2497  return MakeAddrLValue(I->second, T);
2498  }
2499  LValue CapLVal =
2502  return MakeAddrLValue(
2503  Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2505  CapLVal.getTBAAInfo());
2506  }
2507 
2508  assert(isa<BlockDecl>(CurCodeDecl));
2509  Address addr = GetAddrOfBlockDecl(VD);
2510  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2511  }
2512  }
2513 
2514  // FIXME: We should be able to assert this for FunctionDecls as well!
2515  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2516  // those with a valid source location.
2517  assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2518  !E->getLocation().isValid()) &&
2519  "Should not use decl without marking it used!");
2520 
2521  if (ND->hasAttr<WeakRefAttr>()) {
2522  const auto *VD = cast<ValueDecl>(ND);
2523  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2524  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2525  }
2526 
2527  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2528  // Check if this is a global variable.
2529  if (VD->hasLinkage() || VD->isStaticDataMember())
2530  return EmitGlobalVarDeclLValue(*this, E, VD);
2531 
2532  Address addr = Address::invalid();
2533 
2534  // The variable should generally be present in the local decl map.
2535  auto iter = LocalDeclMap.find(VD);
2536  if (iter != LocalDeclMap.end()) {
2537  addr = iter->second;
2538 
2539  // Otherwise, it might be static local we haven't emitted yet for
2540  // some reason; most likely, because it's in an outer function.
2541  } else if (VD->isStaticLocal()) {
2543  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2544  getContext().getDeclAlign(VD));
2545 
2546  // No other cases for now.
2547  } else {
2548  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2549  }
2550 
2551 
2552  // Check for OpenMP threadprivate variables.
2553  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2554  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2556  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2557  E->getExprLoc());
2558  }
2559 
2560  // Drill into block byref variables.
2561  bool isBlockByref = VD->isEscapingByref();
2562  if (isBlockByref) {
2563  addr = emitBlockByrefAddress(addr, VD);
2564  }
2565 
2566  // Drill into reference types.
2567  LValue LV = VD->getType()->isReferenceType() ?
2570 
2571  bool isLocalStorage = VD->hasLocalStorage();
2572 
2573  bool NonGCable = isLocalStorage &&
2574  !VD->getType()->isReferenceType() &&
2575  !isBlockByref;
2576  if (NonGCable) {
2577  LV.getQuals().removeObjCGCAttr();
2578  LV.setNonGC(true);
2579  }
2580 
2581  bool isImpreciseLifetime =
2582  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2583  if (isImpreciseLifetime)
2585  setObjCGCLValueClass(getContext(), E, LV);
2586  return LV;
2587  }
2588 
2589  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2590  return EmitFunctionDeclLValue(*this, E, FD);
2591 
2592  // FIXME: While we're emitting a binding from an enclosing scope, all other
2593  // DeclRefExprs we see should be implicitly treated as if they also refer to
2594  // an enclosing scope.
2595  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2596  return EmitLValue(BD->getBinding());
2597 
2598  llvm_unreachable("Unhandled DeclRefExpr");
2599 }
2600 
2602  // __extension__ doesn't affect lvalue-ness.
2603  if (E->getOpcode() == UO_Extension)
2604  return EmitLValue(E->getSubExpr());
2605 
2607  switch (E->getOpcode()) {
2608  default: llvm_unreachable("Unknown unary operator lvalue!");
2609  case UO_Deref: {
2610  QualType T = E->getSubExpr()->getType()->getPointeeType();
2611  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2612 
2613  LValueBaseInfo BaseInfo;
2614  TBAAAccessInfo TBAAInfo;
2615  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2616  &TBAAInfo);
2617  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2618  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2619 
2620  // We should not generate __weak write barrier on indirect reference
2621  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2622  // But, we continue to generate __strong write barrier on indirect write
2623  // into a pointer to object.
2624  if (getLangOpts().ObjC &&
2625  getLangOpts().getGC() != LangOptions::NonGC &&
2626  LV.isObjCWeak())
2627  LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2628  return LV;
2629  }
2630  case UO_Real:
2631  case UO_Imag: {
2632  LValue LV = EmitLValue(E->getSubExpr());
2633  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2634 
2635  // __real is valid on scalars. This is a faster way of testing that.
2636  // __imag can only produce an rvalue on scalars.
2637  if (E->getOpcode() == UO_Real &&
2638  !LV.getAddress().getElementType()->isStructTy()) {
2639  assert(E->getSubExpr()->getType()->isArithmeticType());
2640  return LV;
2641  }
2642 
2643  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2644 
2645  Address Component =
2646  (E->getOpcode() == UO_Real
2649  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2650  CGM.getTBAAInfoForSubobject(LV, T));
2651  ElemLV.getQuals().addQualifiers(LV.getQuals());
2652  return ElemLV;
2653  }
2654  case UO_PreInc:
2655  case UO_PreDec: {
2656  LValue LV = EmitLValue(E->getSubExpr());
2657  bool isInc = E->getOpcode() == UO_PreInc;
2658 
2659  if (E->getType()->isAnyComplexType())
2660  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2661  else
2662  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2663  return LV;
2664  }
2665  }
2666 }
2667 
2671 }
2672 
2676 }
2677 
2679  auto SL = E->getFunctionName();
2680  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2681  StringRef FnName = CurFn->getName();
2682  if (FnName.startswith("\01"))
2683  FnName = FnName.substr(1);
2684  StringRef NameItems[] = {
2686  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2687  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2688  std::string Name = SL->getString();
2689  if (!Name.empty()) {
2690  unsigned Discriminator =
2691  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2692  if (Discriminator)
2693  Name += "_" + Twine(Discriminator + 1).str();
2694  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2695  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2696  } else {
2697  auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2698  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2699  }
2700  }
2701  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2702  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2703 }
2704 
2705 /// Emit a type description suitable for use by a runtime sanitizer library. The
2706 /// format of a type descriptor is
2707 ///
2708 /// \code
2709 /// { i16 TypeKind, i16 TypeInfo }
2710 /// \endcode
2711 ///
2712 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2713 /// integer, 1 for a floating point value, and -1 for anything else.
2715  // Only emit each type's descriptor once.
2716  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2717  return C;
2718 
2719  uint16_t TypeKind = -1;
2720  uint16_t TypeInfo = 0;
2721 
2722  if (T->isIntegerType()) {
2723  TypeKind = 0;
2724  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2725  (T->isSignedIntegerType() ? 1 : 0);
2726  } else if (T->isFloatingType()) {
2727  TypeKind = 1;
2728  TypeInfo = getContext().getTypeSize(T);
2729  }
2730 
2731  // Format the type name as if for a diagnostic, including quotes and
2732  // optionally an 'aka'.
2733  SmallString<32> Buffer;
2735  (intptr_t)T.getAsOpaquePtr(),
2736  StringRef(), StringRef(), None, Buffer,
2737  None);
2738 
2739  llvm::Constant *Components[] = {
2740  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2741  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2742  };
2743  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2744 
2745  auto *GV = new llvm::GlobalVariable(
2746  CGM.getModule(), Descriptor->getType(),
2747  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2748  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2750 
2751  // Remember the descriptor for this type.
2752  CGM.setTypeDescriptorInMap(T, GV);
2753 
2754  return GV;
2755 }
2756 
2758  llvm::Type *TargetTy = IntPtrTy;
2759 
2760  if (V->getType() == TargetTy)
2761  return V;
2762 
2763  // Floating-point types which fit into intptr_t are bitcast to integers
2764  // and then passed directly (after zero-extension, if necessary).
2765  if (V->getType()->isFloatingPointTy()) {
2766  unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2767  if (Bits <= TargetTy->getIntegerBitWidth())
2768  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2769  Bits));
2770  }
2771 
2772  // Integers which fit in intptr_t are zero-extended and passed directly.
2773  if (V->getType()->isIntegerTy() &&
2774  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2775  return Builder.CreateZExt(V, TargetTy);
2776 
2777  // Pointers are passed directly, everything else is passed by address.
2778  if (!V->getType()->isPointerTy()) {
2779  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2780  Builder.CreateStore(V, Ptr);
2781  V = Ptr.getPointer();
2782  }
2783  return Builder.CreatePtrToInt(V, TargetTy);
2784 }
2785 
2786 /// Emit a representation of a SourceLocation for passing to a handler
2787 /// in a sanitizer runtime library. The format for this data is:
2788 /// \code
2789 /// struct SourceLocation {
2790 /// const char *Filename;
2791 /// int32_t Line, Column;
2792 /// };
2793 /// \endcode
2794 /// For an invalid SourceLocation, the Filename pointer is null.
2796  llvm::Constant *Filename;
2797  int Line, Column;
2798 
2800  if (PLoc.isValid()) {
2801  StringRef FilenameString = PLoc.getFilename();
2802 
2803  int PathComponentsToStrip =
2804  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2805  if (PathComponentsToStrip < 0) {
2806  assert(PathComponentsToStrip != INT_MIN);
2807  int PathComponentsToKeep = -PathComponentsToStrip;
2808  auto I = llvm::sys::path::rbegin(FilenameString);
2809  auto E = llvm::sys::path::rend(FilenameString);
2810  while (I != E && --PathComponentsToKeep)
2811  ++I;
2812 
2813  FilenameString = FilenameString.substr(I - E);
2814  } else if (PathComponentsToStrip > 0) {
2815  auto I = llvm::sys::path::begin(FilenameString);
2816  auto E = llvm::sys::path::end(FilenameString);
2817  while (I != E && PathComponentsToStrip--)
2818  ++I;
2819 
2820  if (I != E)
2821  FilenameString =
2822  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2823  else
2824  FilenameString = llvm::sys::path::filename(FilenameString);
2825  }
2826 
2827  auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2829  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2830  Filename = FilenameGV.getPointer();
2831  Line = PLoc.getLine();
2832  Column = PLoc.getColumn();
2833  } else {
2834  Filename = llvm::Constant::getNullValue(Int8PtrTy);
2835  Line = Column = 0;
2836  }
2837 
2838  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2839  Builder.getInt32(Column)};
2840 
2841  return llvm::ConstantStruct::getAnon(Data);
2842 }
2843 
2844 namespace {
2845 /// Specify under what conditions this check can be recovered
2847  /// Always terminate program execution if this check fails.
2848  Unrecoverable,
2849  /// Check supports recovering, runtime has both fatal (noreturn) and
2850  /// non-fatal handlers for this check.
2851  Recoverable,
2852  /// Runtime conditionally aborts, always need to support recovery.
2854 };
2855 }
2856 
2858  assert(Kind.countPopulation() == 1);
2859  if (Kind == SanitizerKind::Vptr)
2861  else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
2863  else
2864  return CheckRecoverableKind::Recoverable;
2865 }
2866 
2867 namespace {
2868 struct SanitizerHandlerInfo {
2869  char const *const Name;
2870  unsigned Version;
2871 };
2872 }
2873 
2874 const SanitizerHandlerInfo SanitizerHandlers[] = {
2875 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2877 #undef SANITIZER_CHECK
2878 };
2879 
2881  llvm::FunctionType *FnType,
2882  ArrayRef<llvm::Value *> FnArgs,
2883  SanitizerHandler CheckHandler,
2884  CheckRecoverableKind RecoverKind, bool IsFatal,
2885  llvm::BasicBlock *ContBB) {
2886  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2888  if (!CGF.Builder.getCurrentDebugLocation()) {
2889  // Ensure that the call has at least an artificial debug location.
2890  DL.emplace(CGF, SourceLocation());
2891  }
2892  bool NeedsAbortSuffix =
2893  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2894  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2895  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2896  const StringRef CheckName = CheckInfo.Name;
2897  std::string FnName = "__ubsan_handle_" + CheckName.str();
2898  if (CheckInfo.Version && !MinimalRuntime)
2899  FnName += "_v" + llvm::utostr(CheckInfo.Version);
2900  if (MinimalRuntime)
2901  FnName += "_minimal";
2902  if (NeedsAbortSuffix)
2903  FnName += "_abort";
2904  bool MayReturn =
2905  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2906 
2907  llvm::AttrBuilder B;
2908  if (!MayReturn) {
2909  B.addAttribute(llvm::Attribute::NoReturn)
2910  .addAttribute(llvm::Attribute::NoUnwind);
2911  }
2912  B.addAttribute(llvm::Attribute::UWTable);
2913 
2914  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
2915  FnType, FnName,
2916  llvm::AttributeList::get(CGF.getLLVMContext(),
2917  llvm::AttributeList::FunctionIndex, B),
2918  /*Local=*/true);
2919  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2920  if (!MayReturn) {
2921  HandlerCall->setDoesNotReturn();
2922  CGF.Builder.CreateUnreachable();
2923  } else {
2924  CGF.Builder.CreateBr(ContBB);
2925  }
2926 }
2927 
2929  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2930  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2931  ArrayRef<llvm::Value *> DynamicArgs) {
2932  assert(IsSanitizerScope);
2933  assert(Checked.size() > 0);
2934  assert(CheckHandler >= 0 &&
2935  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
2936  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2937 
2938  llvm::Value *FatalCond = nullptr;
2939  llvm::Value *RecoverableCond = nullptr;
2940  llvm::Value *TrapCond = nullptr;
2941  for (int i = 0, n = Checked.size(); i < n; ++i) {
2942  llvm::Value *Check = Checked[i].first;
2943  // -fsanitize-trap= overrides -fsanitize-recover=.
2944  llvm::Value *&Cond =
2945  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2946  ? TrapCond
2947  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2948  ? RecoverableCond
2949  : FatalCond;
2950  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2951  }
2952 
2953  if (TrapCond)
2954  EmitTrapCheck(TrapCond);
2955  if (!FatalCond && !RecoverableCond)
2956  return;
2957 
2958  llvm::Value *JointCond;
2959  if (FatalCond && RecoverableCond)
2960  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2961  else
2962  JointCond = FatalCond ? FatalCond : RecoverableCond;
2963  assert(JointCond);
2964 
2965  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2966  assert(SanOpts.has(Checked[0].second));
2967 #ifndef NDEBUG
2968  for (int i = 1, n = Checked.size(); i < n; ++i) {
2969  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2970  "All recoverable kinds in a single check must be same!");
2971  assert(SanOpts.has(Checked[i].second));
2972  }
2973 #endif
2974 
2975  llvm::BasicBlock *Cont = createBasicBlock("cont");
2976  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2977  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2978  // Give hint that we very much don't expect to execute the handler
2979  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2980  llvm::MDBuilder MDHelper(getLLVMContext());
2981  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2982  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2983  EmitBlock(Handlers);
2984 
2985  // Handler functions take an i8* pointing to the (handler-specific) static
2986  // information block, followed by a sequence of intptr_t arguments
2987  // representing operand values.
2990  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
2991  Args.reserve(DynamicArgs.size() + 1);
2992  ArgTypes.reserve(DynamicArgs.size() + 1);
2993 
2994  // Emit handler arguments and create handler function type.
2995  if (!StaticArgs.empty()) {
2996  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2997  auto *InfoPtr =
2998  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2999  llvm::GlobalVariable::PrivateLinkage, Info);
3000  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3002  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3003  ArgTypes.push_back(Int8PtrTy);
3004  }
3005 
3006  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3007  Args.push_back(EmitCheckValue(DynamicArgs[i]));
3008  ArgTypes.push_back(IntPtrTy);
3009  }
3010  }
3011 
3012  llvm::FunctionType *FnType =
3013  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3014 
3015  if (!FatalCond || !RecoverableCond) {
3016  // Simple case: we need to generate a single handler call, either
3017  // fatal, or non-fatal.
3018  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3019  (FatalCond != nullptr), Cont);
3020  } else {
3021  // Emit two handler calls: first one for set of unrecoverable checks,
3022  // another one for recoverable.
3023  llvm::BasicBlock *NonFatalHandlerBB =
3024  createBasicBlock("non_fatal." + CheckName);
3025  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3026  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3027  EmitBlock(FatalHandlerBB);
3028  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3029  NonFatalHandlerBB);
3030  EmitBlock(NonFatalHandlerBB);
3031  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3032  Cont);
3033  }
3034 
3035  EmitBlock(Cont);
3036 }
3037 
3039  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3040  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3041  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3042 
3043  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3044  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3045 
3046  llvm::MDBuilder MDHelper(getLLVMContext());
3047  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3048  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3049 
3050  EmitBlock(CheckBB);
3051 
3052  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3053 
3054  llvm::CallInst *CheckCall;
3055  llvm::FunctionCallee SlowPathFn;
3056  if (WithDiag) {
3057  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3058  auto *InfoPtr =
3059  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3060  llvm::GlobalVariable::PrivateLinkage, Info);
3061  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3063 
3064  SlowPathFn = CGM.getModule().getOrInsertFunction(
3065  "__cfi_slowpath_diag",
3066  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3067  false));
3068  CheckCall = Builder.CreateCall(
3069  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3070  } else {
3071  SlowPathFn = CGM.getModule().getOrInsertFunction(
3072  "__cfi_slowpath",
3073  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3074  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3075  }
3076 
3077  CGM.setDSOLocal(
3078  cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3079  CheckCall->setDoesNotThrow();
3080 
3081  EmitBlock(Cont);
3082 }
3083 
3084 // Emit a stub for __cfi_check function so that the linker knows about this
3085 // symbol in LTO mode.
3087  llvm::Module *M = &CGM.getModule();
3088  auto &Ctx = M->getContext();
3089  llvm::Function *F = llvm::Function::Create(
3090  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3091  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3092  CGM.setDSOLocal(F);
3093  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3094  // FIXME: consider emitting an intrinsic call like
3095  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3096  // which can be lowered in CrossDSOCFI pass to the actual contents of
3097  // __cfi_check. This would allow inlining of __cfi_check calls.
3099  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3100  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3101 }
3102 
3103 // This function is basically a switch over the CFI failure kind, which is
3104 // extracted from CFICheckFailData (1st function argument). Each case is either
3105 // llvm.trap or a call to one of the two runtime handlers, based on
3106 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3107 // failure kind) traps, but this should really never happen. CFICheckFailData
3108 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3109 // check kind; in this case __cfi_check_fail traps as well.
3111  SanitizerScope SanScope(this);
3112  FunctionArgList Args;
3117  Args.push_back(&ArgData);
3118  Args.push_back(&ArgAddr);
3119 
3120  const CGFunctionInfo &FI =
3122 
3123  llvm::Function *F = llvm::Function::Create(
3124  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3125  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3126  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3127 
3128  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3129  SourceLocation());
3130 
3131  // This function should not be affected by blacklist. This function does
3132  // not have a source location, but "src:*" would still apply. Revert any
3133  // changes to SanOpts made in StartFunction.
3135 
3136  llvm::Value *Data =
3137  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3138  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3139  llvm::Value *Addr =
3140  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3141  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3142 
3143  // Data == nullptr means the calling module has trap behaviour for this check.
3144  llvm::Value *DataIsNotNullPtr =
3145  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3146  EmitTrapCheck(DataIsNotNullPtr);
3147 
3148  llvm::StructType *SourceLocationTy =
3149  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3150  llvm::StructType *CfiCheckFailDataTy =
3151  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3152 
3153  llvm::Value *V = Builder.CreateConstGEP2_32(
3154  CfiCheckFailDataTy,
3155  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3156  0);
3157  Address CheckKindAddr(V, getIntAlign());
3158  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3159 
3160  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3161  CGM.getLLVMContext(),
3162  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3163  llvm::Value *ValidVtable = Builder.CreateZExt(
3164  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3165  {Addr, AllVtables}),
3166  IntPtrTy);
3167 
3168  const std::pair<int, SanitizerMask> CheckKinds[] = {
3169  {CFITCK_VCall, SanitizerKind::CFIVCall},
3170  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3171  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3172  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3173  {CFITCK_ICall, SanitizerKind::CFIICall}};
3174 
3176  for (auto CheckKindMaskPair : CheckKinds) {
3177  int Kind = CheckKindMaskPair.first;
3178  SanitizerMask Mask = CheckKindMaskPair.second;
3179  llvm::Value *Cond =
3180  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3181  if (CGM.getLangOpts().Sanitize.has(Mask))
3182  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3183  {Data, Addr, ValidVtable});
3184  else
3185  EmitTrapCheck(Cond);
3186  }
3187 
3188  FinishFunction();
3189  // The only reference to this function will be created during LTO link.
3190  // Make sure it survives until then.
3191  CGM.addUsedGlobal(F);
3192 }
3193 
3195  if (SanOpts.has(SanitizerKind::Unreachable)) {
3196  SanitizerScope SanScope(this);
3197  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3198  SanitizerKind::Unreachable),
3199  SanitizerHandler::BuiltinUnreachable,
3200  EmitCheckSourceLocation(Loc), None);
3201  }
3202  Builder.CreateUnreachable();
3203 }
3204 
3206  llvm::BasicBlock *Cont = createBasicBlock("cont");
3207 
3208  // If we're optimizing, collapse all calls to trap down to just one per
3209  // function to save on code size.
3210  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3211  TrapBB = createBasicBlock("trap");
3212  Builder.CreateCondBr(Checked, Cont, TrapBB);
3213  EmitBlock(TrapBB);
3214  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3215  TrapCall->setDoesNotReturn();
3216  TrapCall->setDoesNotThrow();
3217  Builder.CreateUnreachable();
3218  } else {
3219  Builder.CreateCondBr(Checked, Cont, TrapBB);
3220  }
3221 
3222  EmitBlock(Cont);
3223 }
3224 
3226  llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3227 
3228  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3229  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3231  TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3232  }
3233 
3234  return TrapCall;
3235 }
3236 
3238  LValueBaseInfo *BaseInfo,
3239  TBAAAccessInfo *TBAAInfo) {
3240  assert(E->getType()->isArrayType() &&
3241  "Array to pointer decay must have array source type!");
3242 
3243  // Expressions of array type can't be bitfields or vector elements.
3244  LValue LV = EmitLValue(E);
3245  Address Addr = LV.getAddress();
3246 
3247  // If the array type was an incomplete type, we need to make sure
3248  // the decay ends up being the right type.
3249  llvm::Type *NewTy = ConvertType(E->getType());
3250  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3251 
3252  // Note that VLA pointers are always decayed, so we don't need to do
3253  // anything here.
3254  if (!E->getType()->isVariableArrayType()) {
3255  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3256  "Expected pointer to array");
3257  Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3258  }
3259 
3260  // The result of this decay conversion points to an array element within the
3261  // base lvalue. However, since TBAA currently does not support representing
3262  // accesses to elements of member arrays, we conservatively represent accesses
3263  // to the pointee object as if it had no any base lvalue specified.
3264  // TODO: Support TBAA for member arrays.
3266  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3267  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3268 
3269  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3270 }
3271 
3272 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3273 /// array to pointer, return the array subexpression.
3274 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3275  // If this isn't just an array->pointer decay, bail out.
3276  const auto *CE = dyn_cast<CastExpr>(E);
3277  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3278  return nullptr;
3279 
3280  // If this is a decay from variable width array, bail out.
3281  const Expr *SubExpr = CE->getSubExpr();
3282  if (SubExpr->getType()->isVariableArrayType())
3283  return nullptr;
3284 
3285  return SubExpr;
3286 }
3287 
3289  llvm::Value *ptr,
3290  ArrayRef<llvm::Value*> indices,
3291  bool inbounds,
3292  bool signedIndices,
3293  SourceLocation loc,
3294  const llvm::Twine &name = "arrayidx") {
3295  if (inbounds) {
3296  return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3298  name);
3299  } else {
3300  return CGF.Builder.CreateGEP(ptr, indices, name);
3301  }
3302 }
3303 
3305  llvm::Value *idx,
3306  CharUnits eltSize) {
3307  // If we have a constant index, we can use the exact offset of the
3308  // element we're accessing.
3309  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3310  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3311  return arrayAlign.alignmentAtOffset(offset);
3312 
3313  // Otherwise, use the worst-case alignment for any element.
3314  } else {
3315  return arrayAlign.alignmentOfArrayElement(eltSize);
3316  }
3317 }
3318 
3320  const VariableArrayType *vla) {
3321  QualType eltType;
3322  do {
3323  eltType = vla->getElementType();
3324  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3325  return eltType;
3326 }
3327 
3329  ArrayRef<llvm::Value *> indices,
3330  QualType eltType, bool inbounds,
3331  bool signedIndices, SourceLocation loc,
3332  const llvm::Twine &name = "arrayidx") {
3333  // All the indices except that last must be zero.
3334 #ifndef NDEBUG
3335  for (auto idx : indices.drop_back())
3336  assert(isa<llvm::ConstantInt>(idx) &&
3337  cast<llvm::ConstantInt>(idx)->isZero());
3338 #endif
3339 
3340  // Determine the element size of the statically-sized base. This is
3341  // the thing that the indices are expressed in terms of.
3342  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3343  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3344  }
3345 
3346  // We can use that to compute the best alignment of the element.
3347  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3348  CharUnits eltAlign =
3349  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3350 
3352  CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
3353  return Address(eltPtr, eltAlign);
3354 }
3355 
3357  bool Accessed) {
3358  // The index must always be an integer, which is not an aggregate. Emit it
3359  // in lexical order (this complexity is, sadly, required by C++17).
3360  llvm::Value *IdxPre =
3361  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3362  bool SignedIndices = false;
3363  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3364  auto *Idx = IdxPre;
3365  if (E->getLHS() != E->getIdx()) {
3366  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3367  Idx = EmitScalarExpr(E->getIdx());
3368  }
3369 
3370  QualType IdxTy = E->getIdx()->getType();
3371  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3372  SignedIndices |= IdxSigned;
3373 
3374  if (SanOpts.has(SanitizerKind::ArrayBounds))
3375  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3376 
3377  // Extend or truncate the index type to 32 or 64-bits.
3378  if (Promote && Idx->getType() != IntPtrTy)
3379  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3380 
3381  return Idx;
3382  };
3383  IdxPre = nullptr;
3384 
3385  // If the base is a vector type, then we are forming a vector element lvalue
3386  // with this subscript.
3387  if (E->getBase()->getType()->isVectorType() &&
3388  !isa<ExtVectorElementExpr>(E->getBase())) {
3389  // Emit the vector as an lvalue to get its address.
3390  LValue LHS = EmitLValue(E->getBase());
3391  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3392  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3393  return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3394  LHS.getBaseInfo(), TBAAAccessInfo());
3395  }
3396 
3397  // All the other cases basically behave like simple offsetting.
3398 
3399  // Handle the extvector case we ignored above.
3400  if (isa<ExtVectorElementExpr>(E->getBase())) {
3401  LValue LV = EmitLValue(E->getBase());
3402  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3404 
3405  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3406  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3407  SignedIndices, E->getExprLoc());
3408  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3409  CGM.getTBAAInfoForSubobject(LV, EltType));
3410  }
3411 
3412  LValueBaseInfo EltBaseInfo;
3413  TBAAAccessInfo EltTBAAInfo;
3414  Address Addr = Address::invalid();
3415  if (const VariableArrayType *vla =
3416  getContext().getAsVariableArrayType(E->getType())) {
3417  // The base must be a pointer, which is not an aggregate. Emit
3418  // it. It needs to be emitted first in case it's what captures
3419  // the VLA bounds.
3420  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3421  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3422 
3423  // The element count here is the total number of non-VLA elements.
3424  llvm::Value *numElements = getVLASize(vla).NumElts;
3425 
3426  // Effectively, the multiply by the VLA size is part of the GEP.
3427  // GEP indexes are signed, and scaling an index isn't permitted to
3428  // signed-overflow, so we use the same semantics for our explicit
3429  // multiply. We suppress this if overflow is not undefined behavior.
3430  if (getLangOpts().isSignedOverflowDefined()) {
3431  Idx = Builder.CreateMul(Idx, numElements);
3432  } else {
3433  Idx = Builder.CreateNSWMul(Idx, numElements);
3434  }
3435 
3436  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3438  SignedIndices, E->getExprLoc());
3439 
3440  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3441  // Indexing over an interface, as in "NSString *P; P[4];"
3442 
3443  // Emit the base pointer.
3444  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3445  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3446 
3447  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3448  llvm::Value *InterfaceSizeVal =
3449  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3450 
3451  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3452 
3453  // We don't necessarily build correct LLVM struct types for ObjC
3454  // interfaces, so we can't rely on GEP to do this scaling
3455  // correctly, so we need to cast to i8*. FIXME: is this actually
3456  // true? A lot of other things in the fragile ABI would break...
3457  llvm::Type *OrigBaseTy = Addr.getType();
3458  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3459 
3460  // Do the GEP.
3461  CharUnits EltAlign =
3462  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3463  llvm::Value *EltPtr =
3464  emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3465  SignedIndices, E->getExprLoc());
3466  Addr = Address(EltPtr, EltAlign);
3467 
3468  // Cast back.
3469  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3470  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3471  // If this is A[i] where A is an array, the frontend will have decayed the
3472  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3473  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3474  // "gep x, i" here. Emit one "gep A, 0, i".
3475  assert(Array->getType()->isArrayType() &&
3476  "Array to pointer decay must have array source type!");
3477  LValue ArrayLV;
3478  // For simple multidimensional array indexing, set the 'accessed' flag for
3479  // better bounds-checking of the base expression.
3480  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3481  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3482  else
3483  ArrayLV = EmitLValue(Array);
3484  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3485 
3486  // Propagate the alignment from the array itself to the result.
3487  Addr = emitArraySubscriptGEP(
3488  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3489  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3490  E->getExprLoc());
3491  EltBaseInfo = ArrayLV.getBaseInfo();
3492  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3493  } else {
3494  // The base must be a pointer; emit it with an estimate of its alignment.
3495  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3496  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3497  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3499  SignedIndices, E->getExprLoc());
3500  }
3501 
3502  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3503 
3504  if (getLangOpts().ObjC &&
3505  getLangOpts().getGC() != LangOptions::NonGC) {
3507  setObjCGCLValueClass(getContext(), E, LV);
3508  }
3509  return LV;
3510 }
3511 
3513  LValueBaseInfo &BaseInfo,
3514  TBAAAccessInfo &TBAAInfo,
3515  QualType BaseTy, QualType ElTy,
3516  bool IsLowerBound) {
3517  LValue BaseLVal;
3518  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3519  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3520  if (BaseTy->isArrayType()) {
3521  Address Addr = BaseLVal.getAddress();
3522  BaseInfo = BaseLVal.getBaseInfo();
3523 
3524  // If the array type was an incomplete type, we need to make sure
3525  // the decay ends up being the right type.
3526  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3527  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3528 
3529  // Note that VLA pointers are always decayed, so we don't need to do
3530  // anything here.
3531  if (!BaseTy->isVariableArrayType()) {
3532  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3533  "Expected pointer to array");
3534  Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3535  }
3536 
3537  return CGF.Builder.CreateElementBitCast(Addr,
3538  CGF.ConvertTypeForMem(ElTy));
3539  }
3540  LValueBaseInfo TypeBaseInfo;
3541  TBAAAccessInfo TypeTBAAInfo;
3542  CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3543  &TypeTBAAInfo);
3544  BaseInfo.mergeForCast(TypeBaseInfo);
3545  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3546  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3547  }
3548  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3549 }
3550 
3552  bool IsLowerBound) {
3554  QualType ResultExprTy;
3555  if (auto *AT = getContext().getAsArrayType(BaseTy))
3556  ResultExprTy = AT->getElementType();
3557  else
3558  ResultExprTy = BaseTy->getPointeeType();
3559  llvm::Value *Idx = nullptr;
3560  if (IsLowerBound || E->getColonLoc().isInvalid()) {
3561  // Requesting lower bound or upper bound, but without provided length and
3562  // without ':' symbol for the default length -> length = 1.
3563  // Idx = LowerBound ?: 0;
3564  if (auto *LowerBound = E->getLowerBound()) {
3565  Idx = Builder.CreateIntCast(
3566  EmitScalarExpr(LowerBound), IntPtrTy,
3567  LowerBound->getType()->hasSignedIntegerRepresentation());
3568  } else
3569  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3570  } else {
3571  // Try to emit length or lower bound as constant. If this is possible, 1
3572  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3573  // IR (LB + Len) - 1.
3574  auto &C = CGM.getContext();
3575  auto *Length = E->getLength();
3576  llvm::APSInt ConstLength;
3577  if (Length) {
3578  // Idx = LowerBound + Length - 1;
3579  if (Length->isIntegerConstantExpr(ConstLength, C)) {
3580  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3581  Length = nullptr;
3582  }
3583  auto *LowerBound = E->getLowerBound();
3584  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3585  if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3586  ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3587  LowerBound = nullptr;
3588  }
3589  if (!Length)
3590  --ConstLength;
3591  else if (!LowerBound)
3592  --ConstLowerBound;
3593 
3594  if (Length || LowerBound) {
3595  auto *LowerBoundVal =
3596  LowerBound
3597  ? Builder.CreateIntCast(
3598  EmitScalarExpr(LowerBound), IntPtrTy,
3599  LowerBound->getType()->hasSignedIntegerRepresentation())
3600  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3601  auto *LengthVal =
3602  Length
3603  ? Builder.CreateIntCast(
3604  EmitScalarExpr(Length), IntPtrTy,
3605  Length->getType()->hasSignedIntegerRepresentation())
3606  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3607  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3608  /*HasNUW=*/false,
3609  !getLangOpts().isSignedOverflowDefined());
3610  if (Length && LowerBound) {
3611  Idx = Builder.CreateSub(
3612  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3613  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3614  }
3615  } else
3616  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3617  } else {
3618  // Idx = ArraySize - 1;
3619  QualType ArrayTy = BaseTy->isPointerType()
3620  ? E->getBase()->IgnoreParenImpCasts()->getType()
3621  : BaseTy;
3622  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3623  Length = VAT->getSizeExpr();
3624  if (Length->isIntegerConstantExpr(ConstLength, C))
3625  Length = nullptr;
3626  } else {
3627  auto *CAT = C.getAsConstantArrayType(ArrayTy);
3628  ConstLength = CAT->getSize();
3629  }
3630  if (Length) {
3631  auto *LengthVal = Builder.CreateIntCast(
3632  EmitScalarExpr(Length), IntPtrTy,
3633  Length->getType()->hasSignedIntegerRepresentation());
3634  Idx = Builder.CreateSub(
3635  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3636  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3637  } else {
3638  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3639  --ConstLength;
3640  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3641  }
3642  }
3643  }
3644  assert(Idx);
3645 
3646  Address EltPtr = Address::invalid();
3647  LValueBaseInfo BaseInfo;
3648  TBAAAccessInfo TBAAInfo;
3649  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3650  // The base must be a pointer, which is not an aggregate. Emit
3651  // it. It needs to be emitted first in case it's what captures
3652  // the VLA bounds.
3653  Address Base =
3654  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3655  BaseTy, VLA->getElementType(), IsLowerBound);
3656  // The element count here is the total number of non-VLA elements.
3657  llvm::Value *NumElements = getVLASize(VLA).NumElts;
3658 
3659  // Effectively, the multiply by the VLA size is part of the GEP.
3660  // GEP indexes are signed, and scaling an index isn't permitted to
3661  // signed-overflow, so we use the same semantics for our explicit
3662  // multiply. We suppress this if overflow is not undefined behavior.
3663  if (getLangOpts().isSignedOverflowDefined())
3664  Idx = Builder.CreateMul(Idx, NumElements);
3665  else
3666  Idx = Builder.CreateNSWMul(Idx, NumElements);
3667  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3669  /*SignedIndices=*/false, E->getExprLoc());
3670  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3671  // If this is A[i] where A is an array, the frontend will have decayed the
3672  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3673  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3674  // "gep x, i" here. Emit one "gep A, 0, i".
3675  assert(Array->getType()->isArrayType() &&
3676  "Array to pointer decay must have array source type!");
3677  LValue ArrayLV;
3678  // For simple multidimensional array indexing, set the 'accessed' flag for
3679  // better bounds-checking of the base expression.
3680  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3681  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3682  else
3683  ArrayLV = EmitLValue(Array);
3684 
3685  // Propagate the alignment from the array itself to the result.
3686  EltPtr = emitArraySubscriptGEP(
3687  *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3688  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3689  /*SignedIndices=*/false, E->getExprLoc());
3690  BaseInfo = ArrayLV.getBaseInfo();
3691  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3692  } else {
3693  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3694  TBAAInfo, BaseTy, ResultExprTy,
3695  IsLowerBound);
3696  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3697  !getLangOpts().isSignedOverflowDefined(),
3698  /*SignedIndices=*/false, E->getExprLoc());
3699  }
3700 
3701  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3702 }
3703 
3706  // Emit the base vector as an l-value.
3707  LValue Base;
3708 
3709  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3710  if (E->isArrow()) {
3711  // If it is a pointer to a vector, emit the address and form an lvalue with
3712  // it.
3713  LValueBaseInfo BaseInfo;
3714  TBAAAccessInfo TBAAInfo;
3715  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3716  const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3717  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3718  Base.getQuals().removeObjCGCAttr();
3719  } else if (E->getBase()->isGLValue()) {
3720  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3721  // emit the base as an lvalue.
3722  assert(E->getBase()->getType()->isVectorType());
3723  Base = EmitLValue(E->getBase());
3724  } else {
3725  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3726  assert(E->getBase()->getType()->isVectorType() &&
3727  "Result must be a vector");
3728  llvm::Value *Vec = EmitScalarExpr(E->getBase());
3729 
3730  // Store the vector to memory (because LValue wants an address).
3731  Address VecMem = CreateMemTemp(E->getBase()->getType());
3732  Builder.CreateStore(Vec, VecMem);
3733  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3735  }
3736 
3737  QualType type =
3739 
3740  // Encode the element access list into a vector of unsigned indices.
3741  SmallVector<uint32_t, 4> Indices;
3742  E->getEncodedElementAccess(Indices);
3743 
3744  if (Base.isSimple()) {
3745  llvm::Constant *CV =
3746  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3747  return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3748  Base.getBaseInfo(), TBAAAccessInfo());
3749  }
3750  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3751 
3752  llvm::Constant *BaseElts = Base.getExtVectorElts();
3754 
3755  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3756  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3757  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3759  Base.getBaseInfo(), TBAAAccessInfo());
3760 }
3761 
3763  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3764  EmitIgnoredExpr(E->getBase());
3765  return EmitDeclRefLValue(DRE);
3766  }
3767 
3768  Expr *BaseExpr = E->getBase();
3769  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3770  LValue BaseLV;
3771  if (E->isArrow()) {
3772  LValueBaseInfo BaseInfo;
3773  TBAAAccessInfo TBAAInfo;
3774  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3775  QualType PtrTy = BaseExpr->getType()->getPointeeType();
3776  SanitizerSet SkippedChecks;
3777  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3778  if (IsBaseCXXThis)
3779  SkippedChecks.set(SanitizerKind::Alignment, true);
3780  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3781  SkippedChecks.set(SanitizerKind::Null, true);
3782  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3783  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3784  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3785  } else
3786  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3787 
3788  NamedDecl *ND = E->getMemberDecl();
3789  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3790  LValue LV = EmitLValueForField(BaseLV, Field);
3791  setObjCGCLValueClass(getContext(), E, LV);
3792  return LV;
3793  }
3794 
3795  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3796  return EmitFunctionDeclLValue(*this, E, FD);
3797 
3798  llvm_unreachable("Unhandled member declaration!");
3799 }
3800 
3801 /// Given that we are currently emitting a lambda, emit an l-value for
3802 /// one of its members.
3804  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3805  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3806  QualType LambdaTagType =
3807  getContext().getTagDeclType(Field->getParent());
3808  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3809  return EmitLValueForField(LambdaLV, Field);
3810 }
3811 
3812 /// Drill down to the storage of a field without walking into
3813 /// reference types.
3814 ///
3815 /// The resulting address doesn't necessarily have the right type.
3817  const FieldDecl *field) {
3818  const RecordDecl *rec = field->getParent();
3819 
3820  unsigned idx =
3821  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3822 
3823  return CGF.Builder.CreateStructGEP(base, idx, field->getName());
3824 }
3825 
3826 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3827  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3828  if (!RD)
3829  return false;
3830 
3831  if (RD->isDynamicClass())
3832  return true;
3833 
3834  for (const auto &Base : RD->bases())
3835  if (hasAnyVptr(Base.getType(), Context))
3836  return true;
3837 
3838  for (const FieldDecl *Field : RD->fields())
3839  if (hasAnyVptr(Field->getType(), Context))
3840  return true;
3841 
3842  return false;
3843 }
3844 
3846  const FieldDecl *field) {
3847  LValueBaseInfo BaseInfo = base.getBaseInfo();
3848 
3849  if (field->isBitField()) {
3850  const CGRecordLayout &RL =
3852  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3853  Address Addr = base.getAddress();
3854  unsigned Idx = RL.getLLVMFieldNo(field);
3855  if (Idx != 0)
3856  // For structs, we GEP to the field that the record layout suggests.
3857  Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
3858  // Get the access type.
3859  llvm::Type *FieldIntTy =
3860  llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3861  if (Addr.getElementType() != FieldIntTy)
3862  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3863 
3864  QualType fieldType =
3865  field->getType().withCVRQualifiers(base.getVRQualifiers());
3866  // TODO: Support TBAA for bit fields.
3867  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
3868  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
3869  TBAAAccessInfo());
3870  }
3871 
3872  // Fields of may-alias structures are may-alias themselves.
3873  // FIXME: this should get propagated down through anonymous structs
3874  // and unions.
3875  QualType FieldType = field->getType();
3876  const RecordDecl *rec = field->getParent();
3877  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
3878  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
3879  TBAAAccessInfo FieldTBAAInfo;
3880  if (base.getTBAAInfo().isMayAlias() ||
3881  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
3882  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3883  } else if (rec->isUnion()) {
3884  // TODO: Support TBAA for unions.
3885  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3886  } else {
3887  // If no base type been assigned for the base access, then try to generate
3888  // one for this base lvalue.
3889  FieldTBAAInfo = base.getTBAAInfo();
3890  if (!FieldTBAAInfo.BaseType) {
3891  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
3892  assert(!FieldTBAAInfo.Offset &&
3893  "Nonzero offset for an access with no base type!");
3894  }
3895 
3896  // Adjust offset to be relative to the base type.
3897  const ASTRecordLayout &Layout =
3899  unsigned CharWidth = getContext().getCharWidth();
3900  if (FieldTBAAInfo.BaseType)
3901  FieldTBAAInfo.Offset +=
3902  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
3903 
3904  // Update the final access type and size.
3905  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
3906  FieldTBAAInfo.Size =
3907  getContext().getTypeSizeInChars(FieldType).getQuantity();
3908  }
3909 
3910  Address addr = base.getAddress();
3911  if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
3912  if (CGM.getCodeGenOpts().StrictVTablePointers &&
3913  ClassDef->isDynamicClass()) {
3914  // Getting to any field of dynamic object requires stripping dynamic
3915  // information provided by invariant.group. This is because accessing
3916  // fields may leak the real address of dynamic object, which could result
3917  // in miscompilation when leaked pointer would be compared.
3918  auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
3919  addr = Address(stripped, addr.getAlignment());
3920  }
3921  }
3922 
3923  unsigned RecordCVR = base.getVRQualifiers();
3924  if (rec->isUnion()) {
3925  // For unions, there is no pointer adjustment.
3926  assert(!FieldType->isReferenceType() && "union has reference member");
3927  if (CGM.getCodeGenOpts().StrictVTablePointers &&
3928  hasAnyVptr(FieldType, getContext()))
3929  // Because unions can easily skip invariant.barriers, we need to add
3930  // a barrier every time CXXRecord field with vptr is referenced.
3931  addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
3932  addr.getAlignment());
3933  } else {
3934  // For structs, we GEP to the field that the record layout suggests.
3935  addr = emitAddrOfFieldStorage(*this, addr, field);
3936 
3937  // If this is a reference field, load the reference right now.
3938  if (FieldType->isReferenceType()) {
3939  LValue RefLVal = MakeAddrLValue(addr, FieldType, FieldBaseInfo,
3940  FieldTBAAInfo);
3941  if (RecordCVR & Qualifiers::Volatile)
3942  RefLVal.getQuals().addVolatile();
3943  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
3944 
3945  // Qualifiers on the struct don't apply to the referencee.
3946  RecordCVR = 0;
3947  FieldType = FieldType->getPointeeType();
3948  }
3949  }
3950 
3951  // Make sure that the address is pointing to the right type. This is critical
3952  // for both unions and structs. A union needs a bitcast, a struct element
3953  // will need a bitcast if the LLVM type laid out doesn't match the desired
3954  // type.
3956  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
3957 
3958  if (field->hasAttr<AnnotateAttr>())
3959  addr = EmitFieldAnnotations(field, addr);
3960 
3961  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
3962  LV.getQuals().addCVRQualifiers(RecordCVR);
3963 
3964  // __weak attribute on a field is ignored.
3965  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3966  LV.getQuals().removeObjCGCAttr();
3967 
3968  return LV;
3969 }
3970 
3971 LValue
3973  const FieldDecl *Field) {
3974  QualType FieldType = Field->getType();
3975 
3976  if (!FieldType->isReferenceType())
3977  return EmitLValueForField(Base, Field);
3978 
3979  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3980 
3981  // Make sure that the address is pointing to the right type.
3982  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3983  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3984 
3985  // TODO: Generate TBAA information that describes this access as a structure
3986  // member access and not just an access to an object of the field's type. This
3987  // should be similar to what we do in EmitLValueForField().
3988  LValueBaseInfo BaseInfo = Base.getBaseInfo();
3989  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
3990  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
3991  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
3992  CGM.getTBAAInfoForSubobject(Base, FieldType));
3993 }
3994 
3996  if (E->isFileScope()) {
3998  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3999  }
4000  if (E->getType()->isVariablyModifiedType())
4001  // make sure to emit the VLA size.
4003 
4004  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4005  const Expr *InitExpr = E->getInitializer();
4006  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4007 
4008  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4009  /*Init*/ true);
4010 
4011  return Result;
4012 }
4013 
4015  if (!E->isGLValue())
4016  // Initializing an aggregate temporary in C++11: T{...}.
4017  return EmitAggExprToLValue(E);
4018 
4019  // An lvalue initializer list must be initializing a reference.
4020  assert(E->isTransparent() && "non-transparent glvalue init list");
4021  return EmitLValue(E->getInit(0));
4022 }
4023 
4024 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4025 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4026 /// LValue is returned and the current block has been terminated.
4028  const Expr *Operand) {
4029  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4030  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4031  return None;
4032  }
4033 
4034  return CGF.EmitLValue(Operand);
4035 }
4036 
4039  if (!expr->isGLValue()) {
4040  // ?: here should be an aggregate.
4041  assert(hasAggregateEvaluationKind(expr->getType()) &&
4042  "Unexpected conditional operator!");
4043  return EmitAggExprToLValue(expr);
4044  }
4045 
4046  OpaqueValueMapping binding(*this, expr);
4047 
4048  const Expr *condExpr = expr->getCond();
4049  bool CondExprBool;
4050  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4051  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4052  if (!CondExprBool) std::swap(live, dead);
4053 
4054  if (!ContainsLabel(dead)) {
4055  // If the true case is live, we need to track its region.
4056  if (CondExprBool)
4058  return EmitLValue(live);
4059  }
4060  }
4061 
4062  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4063  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4064  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4065 
4066  ConditionalEvaluation eval(*this);
4067  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4068 
4069  // Any temporaries created here are conditional.
4070  EmitBlock(lhsBlock);
4072  eval.begin(*this);
4073  Optional<LValue> lhs =
4074  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4075  eval.end(*this);
4076 
4077  if (lhs && !lhs->isSimple())
4078  return EmitUnsupportedLValue(expr, "conditional operator");
4079 
4080  lhsBlock = Builder.GetInsertBlock();
4081  if (lhs)
4082  Builder.CreateBr(contBlock);
4083 
4084  // Any temporaries created here are conditional.
4085  EmitBlock(rhsBlock);
4086  eval.begin(*this);
4087  Optional<LValue> rhs =
4088  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4089  eval.end(*this);
4090  if (rhs && !rhs->isSimple())
4091  return EmitUnsupportedLValue(expr, "conditional operator");
4092  rhsBlock = Builder.GetInsertBlock();
4093 
4094  EmitBlock(contBlock);
4095 
4096  if (lhs && rhs) {
4097  llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4098  2, "cond-lvalue");
4099  phi->addIncoming(lhs->getPointer(), lhsBlock);
4100  phi->addIncoming(rhs->getPointer(), rhsBlock);
4101  Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4102  AlignmentSource alignSource =
4103  std::max(lhs->getBaseInfo().getAlignmentSource(),
4104  rhs->getBaseInfo().getAlignmentSource());
4106  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4107  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4108  TBAAInfo);
4109  } else {
4110  assert((lhs || rhs) &&
4111  "both operands of glvalue conditional are throw-expressions?");
4112  return lhs ? *lhs : *rhs;
4113  }
4114 }
4115 
4116 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4117 /// type. If the cast is to a reference, we can have the usual lvalue result,
4118 /// otherwise if a cast is needed by the code generator in an lvalue context,
4119 /// then it must mean that we need the address of an aggregate in order to
4120 /// access one of its members. This can happen for all the reasons that casts
4121 /// are permitted with aggregate result, including noop aggregate casts, and
4122 /// cast from scalar to union.
4124  switch (E->getCastKind()) {
4125  case CK_ToVoid:
4126  case CK_BitCast:
4127  case CK_ArrayToPointerDecay:
4128  case CK_FunctionToPointerDecay:
4129  case CK_NullToMemberPointer:
4130  case CK_NullToPointer:
4131  case CK_IntegralToPointer:
4132  case CK_PointerToIntegral:
4133  case CK_PointerToBoolean:
4134  case CK_VectorSplat:
4135  case CK_IntegralCast:
4136  case CK_BooleanToSignedIntegral:
4137  case CK_IntegralToBoolean:
4138  case CK_IntegralToFloating:
4139  case CK_FloatingToIntegral:
4140  case CK_FloatingToBoolean:
4141  case CK_FloatingCast:
4142  case CK_FloatingRealToComplex:
4143  case CK_FloatingComplexToReal:
4144  case CK_FloatingComplexToBoolean:
4145  case CK_FloatingComplexCast:
4146  case CK_FloatingComplexToIntegralComplex:
4147  case CK_IntegralRealToComplex:
4148  case CK_IntegralComplexToReal:
4149  case CK_IntegralComplexToBoolean:
4150  case CK_IntegralComplexCast:
4151  case CK_IntegralComplexToFloatingComplex:
4152  case CK_DerivedToBaseMemberPointer:
4153  case CK_BaseToDerivedMemberPointer:
4154  case CK_MemberPointerToBoolean:
4155  case CK_ReinterpretMemberPointer:
4156  case CK_AnyPointerToBlockPointerCast:
4157  case CK_ARCProduceObject:
4158  case CK_ARCConsumeObject:
4159  case CK_ARCReclaimReturnedObject:
4160  case CK_ARCExtendBlockObject:
4161  case CK_CopyAndAutoreleaseBlockObject:
4162  case CK_IntToOCLSampler:
4163  case CK_FixedPointCast:
4164  case CK_FixedPointToBoolean:
4165  case CK_FixedPointToIntegral:
4166  case CK_IntegralToFixedPoint:
4167  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4168 
4169  case CK_Dependent:
4170  llvm_unreachable("dependent cast kind in IR gen!");
4171 
4172  case CK_BuiltinFnToFnPtr:
4173  llvm_unreachable("builtin functions are handled elsewhere");
4174 
4175  // These are never l-values; just use the aggregate emission code.
4176  case CK_NonAtomicToAtomic:
4177  case CK_AtomicToNonAtomic:
4178  return EmitAggExprToLValue(E);
4179 
4180  case CK_Dynamic: {
4181  LValue LV = EmitLValue(E->getSubExpr());
4182  Address V = LV.getAddress();
4183  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4184  return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4185  }
4186 
4187  case CK_ConstructorConversion:
4188  case CK_UserDefinedConversion:
4189  case CK_CPointerToObjCPointerCast:
4190  case CK_BlockPointerToObjCPointerCast:
4191  case CK_NoOp:
4192  case CK_LValueToRValue:
4193  return EmitLValue(E->getSubExpr());
4194 
4195  case CK_UncheckedDerivedToBase:
4196  case CK_DerivedToBase: {
4197  const RecordType *DerivedClassTy =
4198  E->getSubExpr()->getType()->getAs<RecordType>();
4199  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4200 
4201  LValue LV = EmitLValue(E->getSubExpr());
4202  Address This = LV.getAddress();
4203 
4204  // Perform the derived-to-base conversion
4206  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4207  /*NullCheckValue=*/false, E->getExprLoc());
4208 
4209  // TODO: Support accesses to members of base classes in TBAA. For now, we
4210  // conservatively pretend that the complete object is of the base class
4211  // type.
4212  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4213  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4214  }
4215  case CK_ToUnion:
4216  return EmitAggExprToLValue(E);
4217  case CK_BaseToDerived: {
4218  const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4219  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4220 
4221  LValue LV = EmitLValue(E->getSubExpr());
4222 
4223  // Perform the base-to-derived conversion
4224  Address Derived =
4225  GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4226  E->path_begin(), E->path_end(),
4227  /*NullCheckValue=*/false);
4228 
4229  // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4230  // performed and the object is not of the derived type.
4233  Derived.getPointer(), E->getType());
4234 
4235  if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4236  EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4237  /*MayBeNull=*/false, CFITCK_DerivedCast,
4238  E->getBeginLoc());
4239 
4240  return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4241  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4242  }
4243  case CK_LValueBitCast: {
4244  // This must be a reinterpret_cast (or c-style equivalent).
4245  const auto *CE = cast<ExplicitCastExpr>(E);
4246 
4247  CGM.EmitExplicitCastExprType(CE, this);
4248  LValue LV = EmitLValue(E->getSubExpr());
4250  ConvertType(CE->getTypeAsWritten()));
4251 
4252  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4253  EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4254  /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4255  E->getBeginLoc());
4256 
4257  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4258  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4259  }
4260  case CK_AddressSpaceConversion: {
4261  LValue LV = EmitLValue(E->getSubExpr());
4262  QualType DestTy = getContext().getPointerType(E->getType());
4264  *this, LV.getPointer(), E->getSubExpr()->getType().getAddressSpace(),
4265  E->getType().getAddressSpace(), ConvertType(DestTy));
4266  return MakeAddrLValue(Address(V, LV.getAddress().getAlignment()),
4267  E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4268  }
4269  case CK_ObjCObjectLValueCast: {
4270  LValue LV = EmitLValue(E->getSubExpr());
4272  ConvertType(E->getType()));
4273  return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4274  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4275  }
4276  case CK_ZeroToOCLOpaqueType:
4277  llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4278  }
4279 
4280  llvm_unreachable("Unhandled lvalue cast kind?");
4281 }
4282 
4286 }
4287 
4288 LValue
4291 
4292  llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4293  it = OpaqueLValues.find(e);
4294 
4295  if (it != OpaqueLValues.end())
4296  return it->second;
4297 
4298  assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4299  return EmitLValue(e->getSourceExpr());
4300 }
4301 
4302 RValue
4305 
4306  llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4307  it = OpaqueRValues.find(e);
4308 
4309  if (it != OpaqueRValues.end())
4310  return it->second;
4311 
4312  assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4313  return EmitAnyExpr(e->getSourceExpr());
4314 }
4315 
4317  const FieldDecl *FD,
4318  SourceLocation Loc) {
4319  QualType FT = FD->getType();
4320  LValue FieldLV = EmitLValueForField(LV, FD);
4321  switch (getEvaluationKind(FT)) {
4322  case TEK_Complex:
4323  return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4324  case TEK_Aggregate:
4325  return FieldLV.asAggregateRValue();
4326  case TEK_Scalar:
4327  // This routine is used to load fields one-by-one to perform a copy, so
4328  // don't load reference fields.
4329  if (FD->getType()->isReferenceType())
4330  return RValue::get(FieldLV.getPointer());
4331  return EmitLoadOfLValue(FieldLV, Loc);
4332  }
4333  llvm_unreachable("bad evaluation kind");
4334 }
4335 
4336 //===--------------------------------------------------------------------===//
4337 // Expression Emission
4338 //===--------------------------------------------------------------------===//
4339 
4342  // Builtins never have block type.
4343  if (E->getCallee()->getType()->isBlockPointerType())
4344  return EmitBlockCallExpr(E, ReturnValue);
4345 
4346  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4347  return EmitCXXMemberCallExpr(CE, ReturnValue);
4348 
4349  if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4350  return EmitCUDAKernelCallExpr(CE, ReturnValue);
4351 
4352  if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4353  if (const CXXMethodDecl *MD =
4354  dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4355  return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4356 
4357  CGCallee callee = EmitCallee(E->getCallee());
4358 
4359  if (callee.isBuiltin()) {
4360  return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4361  E, ReturnValue);
4362  }
4363 
4364  if (callee.isPseudoDestructor()) {
4366  }
4367 
4368  return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4369 }
4370 
4371 /// Emit a CallExpr without considering whether it might be a subclass.
4374  CGCallee Callee = EmitCallee(E->getCallee());
4375  return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4376 }
4377 
4379  if (auto builtinID = FD->getBuiltinID()) {
4380  return CGCallee::forBuiltin(builtinID, FD);
4381  }
4382 
4383  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4384  return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
4385 }
4386 
4388  E = E->IgnoreParens();
4389 
4390  // Look through function-to-pointer decay.
4391  if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4392  if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4393  ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4394  return EmitCallee(ICE->getSubExpr());
4395  }
4396 
4397  // Resolve direct calls.
4398  } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4399  if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4400  return EmitDirectCallee(*this, FD);
4401  }
4402  } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4403  if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4404  EmitIgnoredExpr(ME->getBase());
4405  return EmitDirectCallee(*this, FD);
4406  }
4407 
4408  // Look through template substitutions.
4409  } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4410  return EmitCallee(NTTP->getReplacement());
4411 
4412  // Treat pseudo-destructor calls differently.
4413  } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4414  return CGCallee::forPseudoDestructor(PDE);
4415  }
4416 
4417  // Otherwise, we have an indirect reference.
4418  llvm::Value *calleePtr;
4420  if (auto ptrType = E->getType()->getAs<PointerType>()) {
4421  calleePtr = EmitScalarExpr(E);
4422  functionType = ptrType->getPointeeType();
4423  } else {
4424  functionType = E->getType();
4425  calleePtr = EmitLValue(E).getPointer();
4426  }
4427  assert(functionType->isFunctionType());
4428 
4429  GlobalDecl GD;
4430  if (const auto *VD =
4431  dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4432  GD = GlobalDecl(VD);
4433 
4434  CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4435  CGCallee callee(calleeInfo, calleePtr);
4436  return callee;
4437 }
4438 
4440  // Comma expressions just emit their LHS then their RHS as an l-value.
4441  if (E->getOpcode() == BO_Comma) {
4442  EmitIgnoredExpr(E->getLHS());
4444  return EmitLValue(E->getRHS());
4445  }
4446 
4447  if (E->getOpcode() == BO_PtrMemD ||
4448  E->getOpcode() == BO_PtrMemI)
4450 
4451  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4452 
4453  // Note that in all of these cases, __block variables need the RHS
4454  // evaluated first just in case the variable gets moved by the RHS.
4455 
4456  switch (getEvaluationKind(E->getType())) {
4457  case TEK_Scalar: {
4458  switch (E->getLHS()->getType().getObjCLifetime()) {
4460  return EmitARCStoreStrong(E, /*ignored*/ false).first;
4461 
4463  return EmitARCStoreAutoreleasing(E).first;
4464 
4465  // No reason to do any of these differently.
4466  case Qualifiers::OCL_None:
4468  case Qualifiers::OCL_Weak:
4469  break;
4470  }
4471 
4472  RValue RV = EmitAnyExpr(E->getRHS());
4474  if (RV.isScalar())
4476  EmitStoreThroughLValue(RV, LV);
4477  return LV;
4478  }
4479 
4480  case TEK_Complex:
4481  return EmitComplexAssignmentLValue(E);
4482 
4483  case TEK_Aggregate:
4484  return EmitAggExprToLValue(E);
4485  }
4486  llvm_unreachable("bad evaluation kind");
4487 }
4488 
4490  RValue RV = EmitCallExpr(E);
4491 
4492  if (!RV.isScalar())
4493  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4495 
4496  assert(E->getCallReturnType(getContext())->isReferenceType() &&
4497  "Can't have a scalar return unless the return type is a "
4498  "reference type!");
4499 
4501 }
4502 
4504  // FIXME: This shouldn't require another copy.
4505  return EmitAggExprToLValue(E);
4506 }
4507 
4510  && "binding l-value to type which needs a temporary");
4511  AggValueSlot Slot = CreateAggTemp(E->getType());
4512  EmitCXXConstructExpr(E, Slot);
4513  return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4514 }
4515 
4516 LValue
4519 }
4520 
4523  ConvertType(E->getType()));
4524 }
4525 
4527  return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4529 }
4530 
4531 LValue
4533  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4534  Slot.setExternallyDestructed();
4535  EmitAggExpr(E->getSubExpr(), Slot);
4536  EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4538 }
4539 
4541  RValue RV = EmitObjCMessageExpr(E);
4542 
4543  if (!RV.isScalar())
4544  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4546 
4547  assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4548  "Can't have a scalar return unless the return type is a "
4549  "reference type!");
4550 
4552 }
4553 
4555  Address V =
4557  return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4558 }
4559 
4561  const ObjCIvarDecl *Ivar) {
4562  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4563 }
4564 
4566  llvm::Value *BaseValue,
4567  const ObjCIvarDecl *Ivar,
4568  unsigned CVRQualifiers) {
4569  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4570  Ivar, CVRQualifiers);
4571 }
4572 
4574  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4575  llvm::Value *BaseValue = nullptr;
4576  const Expr *BaseExpr = E->getBase();
4577  Qualifiers BaseQuals;
4578  QualType ObjectTy;
4579  if (E->isArrow()) {
4580  BaseValue = EmitScalarExpr(BaseExpr);
4581  ObjectTy = BaseExpr->getType()->getPointeeType();
4582  BaseQuals = ObjectTy.getQualifiers();
4583  } else {
4584  LValue BaseLV = EmitLValue(BaseExpr);
4585  BaseValue = BaseLV.getPointer();
4586  ObjectTy = BaseExpr->getType();
4587  BaseQuals = ObjectTy.getQualifiers();
4588  }
4589 
4590  LValue LV =
4591  EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4592  BaseQuals.getCVRQualifiers());
4593  setObjCGCLValueClass(getContext(), E, LV);
4594  return LV;
4595 }
4596 
4598  // Can only get l-value for message expression returning aggregate type
4599  RValue RV = EmitAnyExprToTemp(E);
4600  return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4602 }
4603 
4604 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4606  llvm::Value *Chain) {
4607  // Get the actual function type. The callee type will always be a pointer to
4608  // function type or a block pointer type.
4609  assert(CalleeType->isFunctionPointerType() &&
4610  "Call must have function pointer type!");
4611 
4612  const Decl *TargetDecl =
4613  OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
4614 
4615  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4616  // We can only guarantee that a function is called from the correct
4617  // context/function based on the appropriate target attributes,
4618  // so only check in the case where we have both always_inline and target
4619  // since otherwise we could be making a conditional call after a check for
4620  // the proper cpu features (and it won't cause code generation issues due to
4621  // function based code generation).
4622  if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4623  TargetDecl->hasAttr<TargetAttr>())
4624  checkTargetFeatures(E, FD);
4625 
4626  CalleeType = getContext().getCanonicalType(CalleeType);
4627 
4628  auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4629 
4630  CGCallee Callee = OrigCallee;
4631 
4633  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4634  if (llvm::Constant *PrefixSig =
4636  SanitizerScope SanScope(this);
4637  // Remove any (C++17) exception specifications, to allow calling e.g. a
4638  // noexcept function through a non-noexcept pointer.
4639  auto ProtoTy =
4641  llvm::Constant *FTRTTIConst =
4642  CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4643  llvm::Type *PrefixStructTyElems[] = {PrefixSig->getType(), Int32Ty};
4644  llvm::StructType *PrefixStructTy = llvm::StructType::get(
4645  CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4646 
4647  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4648 
4649  llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4650  CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4651  llvm::Value *CalleeSigPtr =
4652  Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4653  llvm::Value *CalleeSig =
4654  Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4655  llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4656 
4657  llvm::BasicBlock *Cont = createBasicBlock("cont");
4658  llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4659  Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4660 
4661  EmitBlock(TypeCheck);
4662  llvm::Value *CalleeRTTIPtr =
4663  Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4664  llvm::Value *CalleeRTTIEncoded =
4665  Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4666  llvm::Value *CalleeRTTI =
4667  DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
4668  llvm::Value *CalleeRTTIMatch =
4669  Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4670  llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()),
4671  EmitCheckTypeDescriptor(CalleeType)};
4672  EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4673  SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4674 
4675  Builder.CreateBr(Cont);
4676  EmitBlock(Cont);
4677  }
4678  }
4679 
4680  const auto *FnType = cast<FunctionType>(PointeeType);
4681 
4682  // If we are checking indirect calls and this call is indirect, check that the
4683  // function pointer is a member of the bit set for the function type.
4684  if (SanOpts.has(SanitizerKind::CFIICall) &&
4685  (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4686  SanitizerScope SanScope(this);
4687  EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4688 
4689  llvm::Metadata *MD;
4690  if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
4692  else
4693  MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4694 
4695  llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4696 
4697  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4698  llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4699  llvm::Value *TypeTest = Builder.CreateCall(
4700  CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4701 
4702  auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4703  llvm::Constant *StaticData[] = {
4704  llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4706  EmitCheckTypeDescriptor(QualType(FnType, 0)),
4707  };
4708  if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4709  EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4710  CastedCallee, StaticData);
4711  } else {
4712  EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4713  SanitizerHandler::CFICheckFail, StaticData,
4714  {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4715  }
4716  }
4717 
4718  CallArgList Args;
4719  if (Chain)
4722 
4723  // C++17 requires that we evaluate arguments to a call using assignment syntax
4724  // right-to-left, and that we evaluate arguments to certain other operators
4725  // left-to-right. Note that we allow this to override the order dictated by
4726  // the calling convention on the MS ABI, which means that parameter
4727  // destruction order is not necessarily reverse construction order.
4728  // FIXME: Revisit this based on C++ committee response to unimplementability.
4730  if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4731  if (OCE->isAssignmentOp())
4733  else {
4734  switch (OCE->getOperator()) {
4735  case OO_LessLess:
4736  case OO_GreaterGreater:
4737  case OO_AmpAmp:
4738  case OO_PipePipe:
4739  case OO_Comma:
4740  case OO_ArrowStar:
4742  break;
4743  default:
4744  break;
4745  }
4746  }
4747  }
4748 
4749  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4750  E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4751 
4753  Args, FnType, /*isChainCall=*/Chain);
4754 
4755  // C99 6.5.2.2p6:
4756  // If the expression that denotes the called function has a type
4757  // that does not include a prototype, [the default argument
4758  // promotions are performed]. If the number of arguments does not
4759  // equal the number of parameters, the behavior is undefined. If
4760  // the function is defined with a type that includes a prototype,
4761  // and either the prototype ends with an ellipsis (, ...) or the
4762  // types of the arguments after promotion are not compatible with
4763  // the types of the parameters, the behavior is undefined. If the
4764  // function is defined with a type that does not include a
4765  // prototype, and the types of the arguments after promotion are
4766  // not compatible with those of the parameters after promotion,
4767  // the behavior is undefined [except in some trivial cases].
4768  // That is, in the general case, we should assume that a call
4769  // through an unprototyped function type works like a *non-variadic*
4770  // call. The way we make this work is to cast to the exact type
4771  // of the promoted arguments.
4772  //
4773  // Chain calls use this same code path to add the invisible chain parameter
4774  // to the function type.
4775  if (isa<FunctionNoProtoType>(FnType) || Chain) {
4776  llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4777  CalleeTy = CalleeTy->getPointerTo();
4778 
4779  llvm::Value *CalleePtr = Callee.getFunctionPointer();
4780  CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4781  Callee.setFunctionPointer(CalleePtr);
4782  }
4783 
4784  return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr, E->getExprLoc());
4785 }
4786 
4789  Address BaseAddr = Address::invalid();
4790  if (E->