xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CGExpr.cpp (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
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 "CGCUDARuntime.h"
14 #include "CGCXXABI.h"
15 #include "CGCall.h"
16 #include "CGCleanup.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CGOpenMPRuntime.h"
20 #include "CGRecordLayout.h"
21 #include "CodeGenFunction.h"
22 #include "CodeGenModule.h"
23 #include "ConstantEmitter.h"
24 #include "TargetInfo.h"
25 #include "clang/AST/ASTContext.h"
26 #include "clang/AST/Attr.h"
27 #include "clang/AST/DeclObjC.h"
28 #include "clang/AST/NSAPI.h"
29 #include "clang/Basic/Builtins.h"
30 #include "clang/Basic/CodeGenOptions.h"
31 #include "clang/Basic/SourceManager.h"
32 #include "llvm/ADT/Hashing.h"
33 #include "llvm/ADT/StringExtras.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/Intrinsics.h"
36 #include "llvm/IR/LLVMContext.h"
37 #include "llvm/IR/MDBuilder.h"
38 #include "llvm/IR/MatrixBuilder.h"
39 #include "llvm/Support/ConvertUTF.h"
40 #include "llvm/Support/MathExtras.h"
41 #include "llvm/Support/Path.h"
42 #include "llvm/Support/SaveAndRestore.h"
43 #include "llvm/Transforms/Utils/SanitizerStats.h"
44 
45 #include <string>
46 
47 using namespace clang;
48 using namespace CodeGen;
49 
50 //===--------------------------------------------------------------------===//
51 //                        Miscellaneous Helper Methods
52 //===--------------------------------------------------------------------===//
53 
54 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
55   unsigned addressSpace =
56       cast<llvm::PointerType>(value->getType())->getAddressSpace();
57 
58   llvm::PointerType *destType = Int8PtrTy;
59   if (addressSpace)
60     destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
61 
62   if (value->getType() == destType) return value;
63   return Builder.CreateBitCast(value, destType);
64 }
65 
66 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
67 /// block.
68 Address CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty,
69                                                      CharUnits Align,
70                                                      const Twine &Name,
71                                                      llvm::Value *ArraySize) {
72   auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
73   Alloca->setAlignment(Align.getAsAlign());
74   return Address(Alloca, Ty, Align);
75 }
76 
77 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
78 /// block. The alloca is casted to default address space if necessary.
79 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
80                                           const Twine &Name,
81                                           llvm::Value *ArraySize,
82                                           Address *AllocaAddr) {
83   auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
84   if (AllocaAddr)
85     *AllocaAddr = Alloca;
86   llvm::Value *V = Alloca.getPointer();
87   // Alloca always returns a pointer in alloca address space, which may
88   // be different from the type defined by the language. For example,
89   // in C++ the auto variables are in the default address space. Therefore
90   // cast alloca to the default address space when necessary.
91   if (getASTAllocaAddressSpace() != LangAS::Default) {
92     auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
93     llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
94     // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
95     // otherwise alloca is inserted at the current insertion point of the
96     // builder.
97     if (!ArraySize)
98       Builder.SetInsertPoint(getPostAllocaInsertPoint());
99     V = getTargetHooks().performAddrSpaceCast(
100         *this, V, getASTAllocaAddressSpace(), LangAS::Default,
101         Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
102   }
103 
104   return Address(V, Ty, Align);
105 }
106 
107 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
108 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
109 /// insertion point of the builder.
110 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
111                                                     const Twine &Name,
112                                                     llvm::Value *ArraySize) {
113   if (ArraySize)
114     return Builder.CreateAlloca(Ty, ArraySize, Name);
115   return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
116                               ArraySize, Name, AllocaInsertPt);
117 }
118 
119 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
120 /// default alignment of the corresponding LLVM type, which is *not*
121 /// guaranteed to be related in any way to the expected alignment of
122 /// an AST type that might have been lowered to Ty.
123 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
124                                                       const Twine &Name) {
125   CharUnits Align =
126       CharUnits::fromQuantity(CGM.getDataLayout().getPrefTypeAlignment(Ty));
127   return CreateTempAlloca(Ty, Align, Name);
128 }
129 
130 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
131   CharUnits Align = getContext().getTypeAlignInChars(Ty);
132   return CreateTempAlloca(ConvertType(Ty), Align, Name);
133 }
134 
135 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
136                                        Address *Alloca) {
137   // FIXME: Should we prefer the preferred type alignment here?
138   return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
139 }
140 
141 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
142                                        const Twine &Name, Address *Alloca) {
143   Address Result = CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
144                                     /*ArraySize=*/nullptr, Alloca);
145 
146   if (Ty->isConstantMatrixType()) {
147     auto *ArrayTy = cast<llvm::ArrayType>(Result.getElementType());
148     auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
149                                                 ArrayTy->getNumElements());
150 
151     Result = Address(
152         Builder.CreateBitCast(Result.getPointer(), VectorTy->getPointerTo()),
153         VectorTy, Result.getAlignment());
154   }
155   return Result;
156 }
157 
158 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty, CharUnits Align,
159                                                   const Twine &Name) {
160   return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
161 }
162 
163 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty,
164                                                   const Twine &Name) {
165   return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
166                                   Name);
167 }
168 
169 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
170 /// expression and compare the result against zero, returning an Int1Ty value.
171 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
172   PGO.setCurrentStmt(E);
173   if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
174     llvm::Value *MemPtr = EmitScalarExpr(E);
175     return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
176   }
177 
178   QualType BoolTy = getContext().BoolTy;
179   SourceLocation Loc = E->getExprLoc();
180   CGFPOptionsRAII FPOptsRAII(*this, E);
181   if (!E->getType()->isAnyComplexType())
182     return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
183 
184   return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
185                                        Loc);
186 }
187 
188 /// EmitIgnoredExpr - Emit code to compute the specified expression,
189 /// ignoring the result.
190 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
191   if (E->isPRValue())
192     return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
193 
194   // Just emit it as an l-value and drop the result.
195   EmitLValue(E);
196 }
197 
198 /// EmitAnyExpr - Emit code to compute the specified expression which
199 /// can have any type.  The result is returned as an RValue struct.
200 /// If this is an aggregate expression, AggSlot indicates where the
201 /// result should be returned.
202 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
203                                     AggValueSlot aggSlot,
204                                     bool ignoreResult) {
205   switch (getEvaluationKind(E->getType())) {
206   case TEK_Scalar:
207     return RValue::get(EmitScalarExpr(E, ignoreResult));
208   case TEK_Complex:
209     return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
210   case TEK_Aggregate:
211     if (!ignoreResult && aggSlot.isIgnored())
212       aggSlot = CreateAggTemp(E->getType(), "agg-temp");
213     EmitAggExpr(E, aggSlot);
214     return aggSlot.asRValue();
215   }
216   llvm_unreachable("bad evaluation kind");
217 }
218 
219 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
220 /// always be accessible even if no aggregate location is provided.
221 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
222   AggValueSlot AggSlot = AggValueSlot::ignored();
223 
224   if (hasAggregateEvaluationKind(E->getType()))
225     AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
226   return EmitAnyExpr(E, AggSlot);
227 }
228 
229 /// EmitAnyExprToMem - Evaluate an expression into a given memory
230 /// location.
231 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
232                                        Address Location,
233                                        Qualifiers Quals,
234                                        bool IsInit) {
235   // FIXME: This function should take an LValue as an argument.
236   switch (getEvaluationKind(E->getType())) {
237   case TEK_Complex:
238     EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
239                               /*isInit*/ false);
240     return;
241 
242   case TEK_Aggregate: {
243     EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
244                                          AggValueSlot::IsDestructed_t(IsInit),
245                                          AggValueSlot::DoesNotNeedGCBarriers,
246                                          AggValueSlot::IsAliased_t(!IsInit),
247                                          AggValueSlot::MayOverlap));
248     return;
249   }
250 
251   case TEK_Scalar: {
252     RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
253     LValue LV = MakeAddrLValue(Location, E->getType());
254     EmitStoreThroughLValue(RV, LV);
255     return;
256   }
257   }
258   llvm_unreachable("bad evaluation kind");
259 }
260 
261 static void
262 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
263                      const Expr *E, Address ReferenceTemporary) {
264   // Objective-C++ ARC:
265   //   If we are binding a reference to a temporary that has ownership, we
266   //   need to perform retain/release operations on the temporary.
267   //
268   // FIXME: This should be looking at E, not M.
269   if (auto Lifetime = M->getType().getObjCLifetime()) {
270     switch (Lifetime) {
271     case Qualifiers::OCL_None:
272     case Qualifiers::OCL_ExplicitNone:
273       // Carry on to normal cleanup handling.
274       break;
275 
276     case Qualifiers::OCL_Autoreleasing:
277       // Nothing to do; cleaned up by an autorelease pool.
278       return;
279 
280     case Qualifiers::OCL_Strong:
281     case Qualifiers::OCL_Weak:
282       switch (StorageDuration Duration = M->getStorageDuration()) {
283       case SD_Static:
284         // Note: we intentionally do not register a cleanup to release
285         // the object on program termination.
286         return;
287 
288       case SD_Thread:
289         // FIXME: We should probably register a cleanup in this case.
290         return;
291 
292       case SD_Automatic:
293       case SD_FullExpression:
294         CodeGenFunction::Destroyer *Destroy;
295         CleanupKind CleanupKind;
296         if (Lifetime == Qualifiers::OCL_Strong) {
297           const ValueDecl *VD = M->getExtendingDecl();
298           bool Precise =
299               VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
300           CleanupKind = CGF.getARCCleanupKind();
301           Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
302                             : &CodeGenFunction::destroyARCStrongImprecise;
303         } else {
304           // __weak objects always get EH cleanups; otherwise, exceptions
305           // could cause really nasty crashes instead of mere leaks.
306           CleanupKind = NormalAndEHCleanup;
307           Destroy = &CodeGenFunction::destroyARCWeak;
308         }
309         if (Duration == SD_FullExpression)
310           CGF.pushDestroy(CleanupKind, ReferenceTemporary,
311                           M->getType(), *Destroy,
312                           CleanupKind & EHCleanup);
313         else
314           CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
315                                           M->getType(),
316                                           *Destroy, CleanupKind & EHCleanup);
317         return;
318 
319       case SD_Dynamic:
320         llvm_unreachable("temporary cannot have dynamic storage duration");
321       }
322       llvm_unreachable("unknown storage duration");
323     }
324   }
325 
326   CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
327   if (const RecordType *RT =
328           E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
329     // Get the destructor for the reference temporary.
330     auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
331     if (!ClassDecl->hasTrivialDestructor())
332       ReferenceTemporaryDtor = ClassDecl->getDestructor();
333   }
334 
335   if (!ReferenceTemporaryDtor)
336     return;
337 
338   // Call the destructor for the temporary.
339   switch (M->getStorageDuration()) {
340   case SD_Static:
341   case SD_Thread: {
342     llvm::FunctionCallee CleanupFn;
343     llvm::Constant *CleanupArg;
344     if (E->getType()->isArrayType()) {
345       CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
346           ReferenceTemporary, E->getType(),
347           CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
348           dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
349       CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
350     } else {
351       CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
352           GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
353       CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
354     }
355     CGF.CGM.getCXXABI().registerGlobalDtor(
356         CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
357     break;
358   }
359 
360   case SD_FullExpression:
361     CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
362                     CodeGenFunction::destroyCXXObject,
363                     CGF.getLangOpts().Exceptions);
364     break;
365 
366   case SD_Automatic:
367     CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
368                                     ReferenceTemporary, E->getType(),
369                                     CodeGenFunction::destroyCXXObject,
370                                     CGF.getLangOpts().Exceptions);
371     break;
372 
373   case SD_Dynamic:
374     llvm_unreachable("temporary cannot have dynamic storage duration");
375   }
376 }
377 
378 static Address createReferenceTemporary(CodeGenFunction &CGF,
379                                         const MaterializeTemporaryExpr *M,
380                                         const Expr *Inner,
381                                         Address *Alloca = nullptr) {
382   auto &TCG = CGF.getTargetHooks();
383   switch (M->getStorageDuration()) {
384   case SD_FullExpression:
385   case SD_Automatic: {
386     // If we have a constant temporary array or record try to promote it into a
387     // constant global under the same rules a normal constant would've been
388     // promoted. This is easier on the optimizer and generally emits fewer
389     // instructions.
390     QualType Ty = Inner->getType();
391     if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
392         (Ty->isArrayType() || Ty->isRecordType()) &&
393         CGF.CGM.isTypeConstant(Ty, true))
394       if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
395         auto AS = CGF.CGM.GetGlobalConstantAddressSpace();
396         auto *GV = new llvm::GlobalVariable(
397             CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
398             llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
399             llvm::GlobalValue::NotThreadLocal,
400             CGF.getContext().getTargetAddressSpace(AS));
401         CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
402         GV->setAlignment(alignment.getAsAlign());
403         llvm::Constant *C = GV;
404         if (AS != LangAS::Default)
405           C = TCG.performAddrSpaceCast(
406               CGF.CGM, GV, AS, LangAS::Default,
407               GV->getValueType()->getPointerTo(
408                   CGF.getContext().getTargetAddressSpace(LangAS::Default)));
409         // FIXME: Should we put the new global into a COMDAT?
410         return Address(C, alignment);
411       }
412     return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
413   }
414   case SD_Thread:
415   case SD_Static:
416     return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
417 
418   case SD_Dynamic:
419     llvm_unreachable("temporary can't have dynamic storage duration");
420   }
421   llvm_unreachable("unknown storage duration");
422 }
423 
424 /// Helper method to check if the underlying ABI is AAPCS
425 static bool isAAPCS(const TargetInfo &TargetInfo) {
426   return TargetInfo.getABI().startswith("aapcs");
427 }
428 
429 LValue CodeGenFunction::
430 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
431   const Expr *E = M->getSubExpr();
432 
433   assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
434           !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
435          "Reference should never be pseudo-strong!");
436 
437   // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
438   // as that will cause the lifetime adjustment to be lost for ARC
439   auto ownership = M->getType().getObjCLifetime();
440   if (ownership != Qualifiers::OCL_None &&
441       ownership != Qualifiers::OCL_ExplicitNone) {
442     Address Object = createReferenceTemporary(*this, M, E);
443     if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
444       Object = Address(llvm::ConstantExpr::getBitCast(Var,
445                            ConvertTypeForMem(E->getType())
446                              ->getPointerTo(Object.getAddressSpace())),
447                        Object.getAlignment());
448 
449       // createReferenceTemporary will promote the temporary to a global with a
450       // constant initializer if it can.  It can only do this to a value of
451       // ARC-manageable type if the value is global and therefore "immune" to
452       // ref-counting operations.  Therefore we have no need to emit either a
453       // dynamic initialization or a cleanup and we can just return the address
454       // of the temporary.
455       if (Var->hasInitializer())
456         return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
457 
458       Var->setInitializer(CGM.EmitNullConstant(E->getType()));
459     }
460     LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
461                                        AlignmentSource::Decl);
462 
463     switch (getEvaluationKind(E->getType())) {
464     default: llvm_unreachable("expected scalar or aggregate expression");
465     case TEK_Scalar:
466       EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
467       break;
468     case TEK_Aggregate: {
469       EmitAggExpr(E, AggValueSlot::forAddr(Object,
470                                            E->getType().getQualifiers(),
471                                            AggValueSlot::IsDestructed,
472                                            AggValueSlot::DoesNotNeedGCBarriers,
473                                            AggValueSlot::IsNotAliased,
474                                            AggValueSlot::DoesNotOverlap));
475       break;
476     }
477     }
478 
479     pushTemporaryCleanup(*this, M, E, Object);
480     return RefTempDst;
481   }
482 
483   SmallVector<const Expr *, 2> CommaLHSs;
484   SmallVector<SubobjectAdjustment, 2> Adjustments;
485   E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
486 
487   for (const auto &Ignored : CommaLHSs)
488     EmitIgnoredExpr(Ignored);
489 
490   if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
491     if (opaque->getType()->isRecordType()) {
492       assert(Adjustments.empty());
493       return EmitOpaqueValueLValue(opaque);
494     }
495   }
496 
497   // Create and initialize the reference temporary.
498   Address Alloca = Address::invalid();
499   Address Object = createReferenceTemporary(*this, M, E, &Alloca);
500   if (auto *Var = dyn_cast<llvm::GlobalVariable>(
501           Object.getPointer()->stripPointerCasts())) {
502     Object = Address(llvm::ConstantExpr::getBitCast(
503                          cast<llvm::Constant>(Object.getPointer()),
504                          ConvertTypeForMem(E->getType())->getPointerTo()),
505                      Object.getAlignment());
506     // If the temporary is a global and has a constant initializer or is a
507     // constant temporary that we promoted to a global, we may have already
508     // initialized it.
509     if (!Var->hasInitializer()) {
510       Var->setInitializer(CGM.EmitNullConstant(E->getType()));
511       EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
512     }
513   } else {
514     switch (M->getStorageDuration()) {
515     case SD_Automatic:
516       if (auto *Size = EmitLifetimeStart(
517               CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
518               Alloca.getPointer())) {
519         pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
520                                                   Alloca, Size);
521       }
522       break;
523 
524     case SD_FullExpression: {
525       if (!ShouldEmitLifetimeMarkers)
526         break;
527 
528       // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
529       // marker. Instead, start the lifetime of a conditional temporary earlier
530       // so that it's unconditional. Don't do this with sanitizers which need
531       // more precise lifetime marks.
532       ConditionalEvaluation *OldConditional = nullptr;
533       CGBuilderTy::InsertPoint OldIP;
534       if (isInConditionalBranch() && !E->getType().isDestructedType() &&
535           !SanOpts.has(SanitizerKind::HWAddress) &&
536           !SanOpts.has(SanitizerKind::Memory) &&
537           !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
538         OldConditional = OutermostConditional;
539         OutermostConditional = nullptr;
540 
541         OldIP = Builder.saveIP();
542         llvm::BasicBlock *Block = OldConditional->getStartingBlock();
543         Builder.restoreIP(CGBuilderTy::InsertPoint(
544             Block, llvm::BasicBlock::iterator(Block->back())));
545       }
546 
547       if (auto *Size = EmitLifetimeStart(
548               CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
549               Alloca.getPointer())) {
550         pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
551                                              Size);
552       }
553 
554       if (OldConditional) {
555         OutermostConditional = OldConditional;
556         Builder.restoreIP(OldIP);
557       }
558       break;
559     }
560 
561     default:
562       break;
563     }
564     EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
565   }
566   pushTemporaryCleanup(*this, M, E, Object);
567 
568   // Perform derived-to-base casts and/or field accesses, to get from the
569   // temporary object we created (and, potentially, for which we extended
570   // the lifetime) to the subobject we're binding the reference to.
571   for (SubobjectAdjustment &Adjustment : llvm::reverse(Adjustments)) {
572     switch (Adjustment.Kind) {
573     case SubobjectAdjustment::DerivedToBaseAdjustment:
574       Object =
575           GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
576                                 Adjustment.DerivedToBase.BasePath->path_begin(),
577                                 Adjustment.DerivedToBase.BasePath->path_end(),
578                                 /*NullCheckValue=*/ false, E->getExprLoc());
579       break;
580 
581     case SubobjectAdjustment::FieldAdjustment: {
582       LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl);
583       LV = EmitLValueForField(LV, Adjustment.Field);
584       assert(LV.isSimple() &&
585              "materialized temporary field is not a simple lvalue");
586       Object = LV.getAddress(*this);
587       break;
588     }
589 
590     case SubobjectAdjustment::MemberPointerAdjustment: {
591       llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
592       Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
593                                                Adjustment.Ptr.MPT);
594       break;
595     }
596     }
597   }
598 
599   return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
600 }
601 
602 RValue
603 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
604   // Emit the expression as an lvalue.
605   LValue LV = EmitLValue(E);
606   assert(LV.isSimple());
607   llvm::Value *Value = LV.getPointer(*this);
608 
609   if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
610     // C++11 [dcl.ref]p5 (as amended by core issue 453):
611     //   If a glvalue to which a reference is directly bound designates neither
612     //   an existing object or function of an appropriate type nor a region of
613     //   storage of suitable size and alignment to contain an object of the
614     //   reference's type, the behavior is undefined.
615     QualType Ty = E->getType();
616     EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
617   }
618 
619   return RValue::get(Value);
620 }
621 
622 
623 /// getAccessedFieldNo - Given an encoded value and a result number, return the
624 /// input field number being accessed.
625 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
626                                              const llvm::Constant *Elts) {
627   return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
628       ->getZExtValue();
629 }
630 
631 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
632 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
633                                     llvm::Value *High) {
634   llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
635   llvm::Value *K47 = Builder.getInt64(47);
636   llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
637   llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
638   llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
639   llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
640   return Builder.CreateMul(B1, KMul);
641 }
642 
643 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
644   return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
645          TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation;
646 }
647 
648 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
649   CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
650   return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
651          (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
652           TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
653           TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation);
654 }
655 
656 bool CodeGenFunction::sanitizePerformTypeCheck() const {
657   return SanOpts.has(SanitizerKind::Null) ||
658          SanOpts.has(SanitizerKind::Alignment) ||
659          SanOpts.has(SanitizerKind::ObjectSize) ||
660          SanOpts.has(SanitizerKind::Vptr);
661 }
662 
663 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
664                                     llvm::Value *Ptr, QualType Ty,
665                                     CharUnits Alignment,
666                                     SanitizerSet SkippedChecks,
667                                     llvm::Value *ArraySize) {
668   if (!sanitizePerformTypeCheck())
669     return;
670 
671   // Don't check pointers outside the default address space. The null check
672   // isn't correct, the object-size check isn't supported by LLVM, and we can't
673   // communicate the addresses to the runtime handler for the vptr check.
674   if (Ptr->getType()->getPointerAddressSpace())
675     return;
676 
677   // Don't check pointers to volatile data. The behavior here is implementation-
678   // defined.
679   if (Ty.isVolatileQualified())
680     return;
681 
682   SanitizerScope SanScope(this);
683 
684   SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
685   llvm::BasicBlock *Done = nullptr;
686 
687   // Quickly determine whether we have a pointer to an alloca. It's possible
688   // to skip null checks, and some alignment checks, for these pointers. This
689   // can reduce compile-time significantly.
690   auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
691 
692   llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
693   llvm::Value *IsNonNull = nullptr;
694   bool IsGuaranteedNonNull =
695       SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
696   bool AllowNullPointers = isNullPointerAllowed(TCK);
697   if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
698       !IsGuaranteedNonNull) {
699     // The glvalue must not be an empty glvalue.
700     IsNonNull = Builder.CreateIsNotNull(Ptr);
701 
702     // The IR builder can constant-fold the null check if the pointer points to
703     // a constant.
704     IsGuaranteedNonNull = IsNonNull == True;
705 
706     // Skip the null check if the pointer is known to be non-null.
707     if (!IsGuaranteedNonNull) {
708       if (AllowNullPointers) {
709         // When performing pointer casts, it's OK if the value is null.
710         // Skip the remaining checks in that case.
711         Done = createBasicBlock("null");
712         llvm::BasicBlock *Rest = createBasicBlock("not.null");
713         Builder.CreateCondBr(IsNonNull, Rest, Done);
714         EmitBlock(Rest);
715       } else {
716         Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
717       }
718     }
719   }
720 
721   if (SanOpts.has(SanitizerKind::ObjectSize) &&
722       !SkippedChecks.has(SanitizerKind::ObjectSize) &&
723       !Ty->isIncompleteType()) {
724     uint64_t TySize = CGM.getMinimumObjectSize(Ty).getQuantity();
725     llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
726     if (ArraySize)
727       Size = Builder.CreateMul(Size, ArraySize);
728 
729     // Degenerate case: new X[0] does not need an objectsize check.
730     llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
731     if (!ConstantSize || !ConstantSize->isNullValue()) {
732       // The glvalue must refer to a large enough storage region.
733       // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
734       //        to check this.
735       // FIXME: Get object address space
736       llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
737       llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
738       llvm::Value *Min = Builder.getFalse();
739       llvm::Value *NullIsUnknown = Builder.getFalse();
740       llvm::Value *Dynamic = Builder.getFalse();
741       llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
742       llvm::Value *LargeEnough = Builder.CreateICmpUGE(
743           Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
744       Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
745     }
746   }
747 
748   uint64_t AlignVal = 0;
749   llvm::Value *PtrAsInt = nullptr;
750 
751   if (SanOpts.has(SanitizerKind::Alignment) &&
752       !SkippedChecks.has(SanitizerKind::Alignment)) {
753     AlignVal = Alignment.getQuantity();
754     if (!Ty->isIncompleteType() && !AlignVal)
755       AlignVal = CGM.getNaturalTypeAlignment(Ty, nullptr, nullptr,
756                                              /*ForPointeeType=*/true)
757                      .getQuantity();
758 
759     // The glvalue must be suitably aligned.
760     if (AlignVal > 1 &&
761         (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
762       PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
763       llvm::Value *Align = Builder.CreateAnd(
764           PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
765       llvm::Value *Aligned =
766           Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
767       if (Aligned != True)
768         Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
769     }
770   }
771 
772   if (Checks.size() > 0) {
773     // Make sure we're not losing information. Alignment needs to be a power of
774     // 2
775     assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
776     llvm::Constant *StaticData[] = {
777         EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
778         llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
779         llvm::ConstantInt::get(Int8Ty, TCK)};
780     EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
781               PtrAsInt ? PtrAsInt : Ptr);
782   }
783 
784   // If possible, check that the vptr indicates that there is a subobject of
785   // type Ty at offset zero within this object.
786   //
787   // C++11 [basic.life]p5,6:
788   //   [For storage which does not refer to an object within its lifetime]
789   //   The program has undefined behavior if:
790   //    -- the [pointer or glvalue] is used to access a non-static data member
791   //       or call a non-static member function
792   if (SanOpts.has(SanitizerKind::Vptr) &&
793       !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
794     // Ensure that the pointer is non-null before loading it. If there is no
795     // compile-time guarantee, reuse the run-time null check or emit a new one.
796     if (!IsGuaranteedNonNull) {
797       if (!IsNonNull)
798         IsNonNull = Builder.CreateIsNotNull(Ptr);
799       if (!Done)
800         Done = createBasicBlock("vptr.null");
801       llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
802       Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
803       EmitBlock(VptrNotNull);
804     }
805 
806     // Compute a hash of the mangled name of the type.
807     //
808     // FIXME: This is not guaranteed to be deterministic! Move to a
809     //        fingerprinting mechanism once LLVM provides one. For the time
810     //        being the implementation happens to be deterministic.
811     SmallString<64> MangledName;
812     llvm::raw_svector_ostream Out(MangledName);
813     CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
814                                                      Out);
815 
816     // Contained in NoSanitizeList based on the mangled type.
817     if (!CGM.getContext().getNoSanitizeList().containsType(SanitizerKind::Vptr,
818                                                            Out.str())) {
819       llvm::hash_code TypeHash = hash_value(Out.str());
820 
821       // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
822       llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
823       llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
824       Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
825       llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
826       llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
827 
828       llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
829       Hash = Builder.CreateTrunc(Hash, IntPtrTy);
830 
831       // Look the hash up in our cache.
832       const int CacheSize = 128;
833       llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
834       llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
835                                                      "__ubsan_vptr_type_cache");
836       llvm::Value *Slot = Builder.CreateAnd(Hash,
837                                             llvm::ConstantInt::get(IntPtrTy,
838                                                                    CacheSize-1));
839       llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
840       llvm::Value *CacheVal = Builder.CreateAlignedLoad(
841           IntPtrTy, Builder.CreateInBoundsGEP(HashTable, Cache, Indices),
842           getPointerAlign());
843 
844       // If the hash isn't in the cache, call a runtime handler to perform the
845       // hard work of checking whether the vptr is for an object of the right
846       // type. This will either fill in the cache and return, or produce a
847       // diagnostic.
848       llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
849       llvm::Constant *StaticData[] = {
850         EmitCheckSourceLocation(Loc),
851         EmitCheckTypeDescriptor(Ty),
852         CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
853         llvm::ConstantInt::get(Int8Ty, TCK)
854       };
855       llvm::Value *DynamicData[] = { Ptr, Hash };
856       EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
857                 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
858                 DynamicData);
859     }
860   }
861 
862   if (Done) {
863     Builder.CreateBr(Done);
864     EmitBlock(Done);
865   }
866 }
867 
868 /// Determine whether this expression refers to a flexible array member in a
869 /// struct. We disable array bounds checks for such members.
870 static bool isFlexibleArrayMemberExpr(const Expr *E) {
871   // For compatibility with existing code, we treat arrays of length 0 or
872   // 1 as flexible array members.
873   // FIXME: This is inconsistent with the warning code in SemaChecking. Unify
874   // the two mechanisms.
875   const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
876   if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
877     // FIXME: Sema doesn't treat [1] as a flexible array member if the bound
878     // was produced by macro expansion.
879     if (CAT->getSize().ugt(1))
880       return false;
881   } else if (!isa<IncompleteArrayType>(AT))
882     return false;
883 
884   E = E->IgnoreParens();
885 
886   // A flexible array member must be the last member in the class.
887   if (const auto *ME = dyn_cast<MemberExpr>(E)) {
888     // FIXME: If the base type of the member expr is not FD->getParent(),
889     // this should not be treated as a flexible array member access.
890     if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
891       // FIXME: Sema doesn't treat a T[1] union member as a flexible array
892       // member, only a T[0] or T[] member gets that treatment.
893       if (FD->getParent()->isUnion())
894         return true;
895       RecordDecl::field_iterator FI(
896           DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
897       return ++FI == FD->getParent()->field_end();
898     }
899   } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
900     return IRE->getDecl()->getNextIvar() == nullptr;
901   }
902 
903   return false;
904 }
905 
906 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E,
907                                                    QualType EltTy) {
908   ASTContext &C = getContext();
909   uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
910   if (!EltSize)
911     return nullptr;
912 
913   auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
914   if (!ArrayDeclRef)
915     return nullptr;
916 
917   auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
918   if (!ParamDecl)
919     return nullptr;
920 
921   auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
922   if (!POSAttr)
923     return nullptr;
924 
925   // Don't load the size if it's a lower bound.
926   int POSType = POSAttr->getType();
927   if (POSType != 0 && POSType != 1)
928     return nullptr;
929 
930   // Find the implicit size parameter.
931   auto PassedSizeIt = SizeArguments.find(ParamDecl);
932   if (PassedSizeIt == SizeArguments.end())
933     return nullptr;
934 
935   const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
936   assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
937   Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
938   llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
939                                               C.getSizeType(), E->getExprLoc());
940   llvm::Value *SizeOfElement =
941       llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
942   return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
943 }
944 
945 /// If Base is known to point to the start of an array, return the length of
946 /// that array. Return 0 if the length cannot be determined.
947 static llvm::Value *getArrayIndexingBound(
948     CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
949   // For the vector indexing extension, the bound is the number of elements.
950   if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
951     IndexedType = Base->getType();
952     return CGF.Builder.getInt32(VT->getNumElements());
953   }
954 
955   Base = Base->IgnoreParens();
956 
957   if (const auto *CE = dyn_cast<CastExpr>(Base)) {
958     if (CE->getCastKind() == CK_ArrayToPointerDecay &&
959         !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
960       IndexedType = CE->getSubExpr()->getType();
961       const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
962       if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
963         return CGF.Builder.getInt(CAT->getSize());
964       else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
965         return CGF.getVLASize(VAT).NumElts;
966       // Ignore pass_object_size here. It's not applicable on decayed pointers.
967     }
968   }
969 
970   QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
971   if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
972     IndexedType = Base->getType();
973     return POS;
974   }
975 
976   return nullptr;
977 }
978 
979 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
980                                       llvm::Value *Index, QualType IndexType,
981                                       bool Accessed) {
982   assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
983          "should not be called unless adding bounds checks");
984   SanitizerScope SanScope(this);
985 
986   QualType IndexedType;
987   llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
988   if (!Bound)
989     return;
990 
991   bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
992   llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
993   llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
994 
995   llvm::Constant *StaticData[] = {
996     EmitCheckSourceLocation(E->getExprLoc()),
997     EmitCheckTypeDescriptor(IndexedType),
998     EmitCheckTypeDescriptor(IndexType)
999   };
1000   llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
1001                                 : Builder.CreateICmpULE(IndexVal, BoundVal);
1002   EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
1003             SanitizerHandler::OutOfBounds, StaticData, Index);
1004 }
1005 
1006 
1007 CodeGenFunction::ComplexPairTy CodeGenFunction::
1008 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
1009                          bool isInc, bool isPre) {
1010   ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
1011 
1012   llvm::Value *NextVal;
1013   if (isa<llvm::IntegerType>(InVal.first->getType())) {
1014     uint64_t AmountVal = isInc ? 1 : -1;
1015     NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
1016 
1017     // Add the inc/dec to the real part.
1018     NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1019   } else {
1020     QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
1021     llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1022     if (!isInc)
1023       FVal.changeSign();
1024     NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1025 
1026     // Add the inc/dec to the real part.
1027     NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1028   }
1029 
1030   ComplexPairTy IncVal(NextVal, InVal.second);
1031 
1032   // Store the updated result through the lvalue.
1033   EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1034   if (getLangOpts().OpenMP)
1035     CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
1036                                                               E->getSubExpr());
1037 
1038   // If this is a postinc, return the value read from memory, otherwise use the
1039   // updated value.
1040   return isPre ? IncVal : InVal;
1041 }
1042 
1043 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
1044                                              CodeGenFunction *CGF) {
1045   // Bind VLAs in the cast type.
1046   if (CGF && E->getType()->isVariablyModifiedType())
1047     CGF->EmitVariablyModifiedType(E->getType());
1048 
1049   if (CGDebugInfo *DI = getModuleDebugInfo())
1050     DI->EmitExplicitCastType(E->getType());
1051 }
1052 
1053 //===----------------------------------------------------------------------===//
1054 //                         LValue Expression Emission
1055 //===----------------------------------------------------------------------===//
1056 
1057 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1058 /// derive a more accurate bound on the alignment of the pointer.
1059 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
1060                                                   LValueBaseInfo *BaseInfo,
1061                                                   TBAAAccessInfo *TBAAInfo) {
1062   // We allow this with ObjC object pointers because of fragile ABIs.
1063   assert(E->getType()->isPointerType() ||
1064          E->getType()->isObjCObjectPointerType());
1065   E = E->IgnoreParens();
1066 
1067   // Casts:
1068   if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1069     if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1070       CGM.EmitExplicitCastExprType(ECE, this);
1071 
1072     switch (CE->getCastKind()) {
1073     // Non-converting casts (but not C's implicit conversion from void*).
1074     case CK_BitCast:
1075     case CK_NoOp:
1076     case CK_AddressSpaceConversion:
1077       if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1078         if (PtrTy->getPointeeType()->isVoidType())
1079           break;
1080 
1081         LValueBaseInfo InnerBaseInfo;
1082         TBAAAccessInfo InnerTBAAInfo;
1083         Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1084                                                 &InnerBaseInfo,
1085                                                 &InnerTBAAInfo);
1086         if (BaseInfo) *BaseInfo = InnerBaseInfo;
1087         if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1088 
1089         if (isa<ExplicitCastExpr>(CE)) {
1090           LValueBaseInfo TargetTypeBaseInfo;
1091           TBAAAccessInfo TargetTypeTBAAInfo;
1092           CharUnits Align = CGM.getNaturalPointeeTypeAlignment(
1093               E->getType(), &TargetTypeBaseInfo, &TargetTypeTBAAInfo);
1094           if (TBAAInfo)
1095             *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1096                                                  TargetTypeTBAAInfo);
1097           // If the source l-value is opaque, honor the alignment of the
1098           // casted-to type.
1099           if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1100             if (BaseInfo)
1101               BaseInfo->mergeForCast(TargetTypeBaseInfo);
1102             Addr = Address(Addr.getPointer(), Addr.getElementType(), Align);
1103           }
1104         }
1105 
1106         if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1107             CE->getCastKind() == CK_BitCast) {
1108           if (auto PT = E->getType()->getAs<PointerType>())
1109             EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1110                                       /*MayBeNull=*/true,
1111                                       CodeGenFunction::CFITCK_UnrelatedCast,
1112                                       CE->getBeginLoc());
1113         }
1114 
1115         if (CE->getCastKind() == CK_AddressSpaceConversion)
1116          return Builder.CreateAddrSpaceCast(Addr, ConvertType(E->getType()));
1117 
1118         llvm::Type *ElemTy = ConvertTypeForMem(E->getType()->getPointeeType());
1119         return Builder.CreateElementBitCast(Addr, ElemTy);
1120       }
1121       break;
1122 
1123     // Array-to-pointer decay.
1124     case CK_ArrayToPointerDecay:
1125       return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1126 
1127     // Derived-to-base conversions.
1128     case CK_UncheckedDerivedToBase:
1129     case CK_DerivedToBase: {
1130       // TODO: Support accesses to members of base classes in TBAA. For now, we
1131       // conservatively pretend that the complete object is of the base class
1132       // type.
1133       if (TBAAInfo)
1134         *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1135       Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1136       auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1137       return GetAddressOfBaseClass(Addr, Derived,
1138                                    CE->path_begin(), CE->path_end(),
1139                                    ShouldNullCheckClassCastValue(CE),
1140                                    CE->getExprLoc());
1141     }
1142 
1143     // TODO: Is there any reason to treat base-to-derived conversions
1144     // specially?
1145     default:
1146       break;
1147     }
1148   }
1149 
1150   // Unary &.
1151   if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1152     if (UO->getOpcode() == UO_AddrOf) {
1153       LValue LV = EmitLValue(UO->getSubExpr());
1154       if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1155       if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1156       return LV.getAddress(*this);
1157     }
1158   }
1159 
1160   // TODO: conditional operators, comma.
1161 
1162   // Otherwise, use the alignment of the type.
1163   CharUnits Align =
1164       CGM.getNaturalPointeeTypeAlignment(E->getType(), BaseInfo, TBAAInfo);
1165   llvm::Type *ElemTy = ConvertTypeForMem(E->getType()->getPointeeType());
1166   return Address(EmitScalarExpr(E), ElemTy, Align);
1167 }
1168 
1169 llvm::Value *CodeGenFunction::EmitNonNullRValueCheck(RValue RV, QualType T) {
1170   llvm::Value *V = RV.getScalarVal();
1171   if (auto MPT = T->getAs<MemberPointerType>())
1172     return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, V, MPT);
1173   return Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType()));
1174 }
1175 
1176 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
1177   if (Ty->isVoidType())
1178     return RValue::get(nullptr);
1179 
1180   switch (getEvaluationKind(Ty)) {
1181   case TEK_Complex: {
1182     llvm::Type *EltTy =
1183       ConvertType(Ty->castAs<ComplexType>()->getElementType());
1184     llvm::Value *U = llvm::UndefValue::get(EltTy);
1185     return RValue::getComplex(std::make_pair(U, U));
1186   }
1187 
1188   // If this is a use of an undefined aggregate type, the aggregate must have an
1189   // identifiable address.  Just because the contents of the value are undefined
1190   // doesn't mean that the address can't be taken and compared.
1191   case TEK_Aggregate: {
1192     Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1193     return RValue::getAggregate(DestPtr);
1194   }
1195 
1196   case TEK_Scalar:
1197     return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1198   }
1199   llvm_unreachable("bad evaluation kind");
1200 }
1201 
1202 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1203                                               const char *Name) {
1204   ErrorUnsupported(E, Name);
1205   return GetUndefRValue(E->getType());
1206 }
1207 
1208 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1209                                               const char *Name) {
1210   ErrorUnsupported(E, Name);
1211   llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1212   return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1213                         E->getType());
1214 }
1215 
1216 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1217   const Expr *Base = Obj;
1218   while (!isa<CXXThisExpr>(Base)) {
1219     // The result of a dynamic_cast can be null.
1220     if (isa<CXXDynamicCastExpr>(Base))
1221       return false;
1222 
1223     if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1224       Base = CE->getSubExpr();
1225     } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1226       Base = PE->getSubExpr();
1227     } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1228       if (UO->getOpcode() == UO_Extension)
1229         Base = UO->getSubExpr();
1230       else
1231         return false;
1232     } else {
1233       return false;
1234     }
1235   }
1236   return true;
1237 }
1238 
1239 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1240   LValue LV;
1241   if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1242     LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1243   else
1244     LV = EmitLValue(E);
1245   if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1246     SanitizerSet SkippedChecks;
1247     if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1248       bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1249       if (IsBaseCXXThis)
1250         SkippedChecks.set(SanitizerKind::Alignment, true);
1251       if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1252         SkippedChecks.set(SanitizerKind::Null, true);
1253     }
1254     EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(*this), E->getType(),
1255                   LV.getAlignment(), SkippedChecks);
1256   }
1257   return LV;
1258 }
1259 
1260 /// EmitLValue - Emit code to compute a designator that specifies the location
1261 /// of the expression.
1262 ///
1263 /// This can return one of two things: a simple address or a bitfield reference.
1264 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1265 /// an LLVM pointer type.
1266 ///
1267 /// If this returns a bitfield reference, nothing about the pointee type of the
1268 /// LLVM value is known: For example, it may not be a pointer to an integer.
1269 ///
1270 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1271 /// this method guarantees that the returned pointer type will point to an LLVM
1272 /// type of the same size of the lvalue's type.  If the lvalue has a variable
1273 /// length type, this is not possible.
1274 ///
1275 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1276   ApplyDebugLocation DL(*this, E);
1277   switch (E->getStmtClass()) {
1278   default: return EmitUnsupportedLValue(E, "l-value expression");
1279 
1280   case Expr::ObjCPropertyRefExprClass:
1281     llvm_unreachable("cannot emit a property reference directly");
1282 
1283   case Expr::ObjCSelectorExprClass:
1284     return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1285   case Expr::ObjCIsaExprClass:
1286     return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1287   case Expr::BinaryOperatorClass:
1288     return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1289   case Expr::CompoundAssignOperatorClass: {
1290     QualType Ty = E->getType();
1291     if (const AtomicType *AT = Ty->getAs<AtomicType>())
1292       Ty = AT->getValueType();
1293     if (!Ty->isAnyComplexType())
1294       return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1295     return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1296   }
1297   case Expr::CallExprClass:
1298   case Expr::CXXMemberCallExprClass:
1299   case Expr::CXXOperatorCallExprClass:
1300   case Expr::UserDefinedLiteralClass:
1301     return EmitCallExprLValue(cast<CallExpr>(E));
1302   case Expr::CXXRewrittenBinaryOperatorClass:
1303     return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm());
1304   case Expr::VAArgExprClass:
1305     return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1306   case Expr::DeclRefExprClass:
1307     return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1308   case Expr::ConstantExprClass: {
1309     const ConstantExpr *CE = cast<ConstantExpr>(E);
1310     if (llvm::Value *Result = ConstantEmitter(*this).tryEmitConstantExpr(CE)) {
1311       QualType RetType = cast<CallExpr>(CE->getSubExpr()->IgnoreImplicit())
1312                              ->getCallReturnType(getContext())
1313                              ->getPointeeType();
1314       return MakeNaturalAlignAddrLValue(Result, RetType);
1315     }
1316     return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1317   }
1318   case Expr::ParenExprClass:
1319     return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1320   case Expr::GenericSelectionExprClass:
1321     return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1322   case Expr::PredefinedExprClass:
1323     return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1324   case Expr::StringLiteralClass:
1325     return EmitStringLiteralLValue(cast<StringLiteral>(E));
1326   case Expr::ObjCEncodeExprClass:
1327     return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1328   case Expr::PseudoObjectExprClass:
1329     return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1330   case Expr::InitListExprClass:
1331     return EmitInitListLValue(cast<InitListExpr>(E));
1332   case Expr::CXXTemporaryObjectExprClass:
1333   case Expr::CXXConstructExprClass:
1334     return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1335   case Expr::CXXBindTemporaryExprClass:
1336     return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1337   case Expr::CXXUuidofExprClass:
1338     return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1339   case Expr::LambdaExprClass:
1340     return EmitAggExprToLValue(E);
1341 
1342   case Expr::ExprWithCleanupsClass: {
1343     const auto *cleanups = cast<ExprWithCleanups>(E);
1344     RunCleanupsScope Scope(*this);
1345     LValue LV = EmitLValue(cleanups->getSubExpr());
1346     if (LV.isSimple()) {
1347       // Defend against branches out of gnu statement expressions surrounded by
1348       // cleanups.
1349       Address Addr = LV.getAddress(*this);
1350       llvm::Value *V = Addr.getPointer();
1351       Scope.ForceCleanup({&V});
1352       return LValue::MakeAddr(Addr.withPointer(V), LV.getType(), getContext(),
1353                               LV.getBaseInfo(), LV.getTBAAInfo());
1354     }
1355     // FIXME: Is it possible to create an ExprWithCleanups that produces a
1356     // bitfield lvalue or some other non-simple lvalue?
1357     return LV;
1358   }
1359 
1360   case Expr::CXXDefaultArgExprClass: {
1361     auto *DAE = cast<CXXDefaultArgExpr>(E);
1362     CXXDefaultArgExprScope Scope(*this, DAE);
1363     return EmitLValue(DAE->getExpr());
1364   }
1365   case Expr::CXXDefaultInitExprClass: {
1366     auto *DIE = cast<CXXDefaultInitExpr>(E);
1367     CXXDefaultInitExprScope Scope(*this, DIE);
1368     return EmitLValue(DIE->getExpr());
1369   }
1370   case Expr::CXXTypeidExprClass:
1371     return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1372 
1373   case Expr::ObjCMessageExprClass:
1374     return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1375   case Expr::ObjCIvarRefExprClass:
1376     return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1377   case Expr::StmtExprClass:
1378     return EmitStmtExprLValue(cast<StmtExpr>(E));
1379   case Expr::UnaryOperatorClass:
1380     return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1381   case Expr::ArraySubscriptExprClass:
1382     return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1383   case Expr::MatrixSubscriptExprClass:
1384     return EmitMatrixSubscriptExpr(cast<MatrixSubscriptExpr>(E));
1385   case Expr::OMPArraySectionExprClass:
1386     return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1387   case Expr::ExtVectorElementExprClass:
1388     return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1389   case Expr::MemberExprClass:
1390     return EmitMemberExpr(cast<MemberExpr>(E));
1391   case Expr::CompoundLiteralExprClass:
1392     return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1393   case Expr::ConditionalOperatorClass:
1394     return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1395   case Expr::BinaryConditionalOperatorClass:
1396     return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1397   case Expr::ChooseExprClass:
1398     return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1399   case Expr::OpaqueValueExprClass:
1400     return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1401   case Expr::SubstNonTypeTemplateParmExprClass:
1402     return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1403   case Expr::ImplicitCastExprClass:
1404   case Expr::CStyleCastExprClass:
1405   case Expr::CXXFunctionalCastExprClass:
1406   case Expr::CXXStaticCastExprClass:
1407   case Expr::CXXDynamicCastExprClass:
1408   case Expr::CXXReinterpretCastExprClass:
1409   case Expr::CXXConstCastExprClass:
1410   case Expr::CXXAddrspaceCastExprClass:
1411   case Expr::ObjCBridgedCastExprClass:
1412     return EmitCastLValue(cast<CastExpr>(E));
1413 
1414   case Expr::MaterializeTemporaryExprClass:
1415     return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1416 
1417   case Expr::CoawaitExprClass:
1418     return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1419   case Expr::CoyieldExprClass:
1420     return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1421   }
1422 }
1423 
1424 /// Given an object of the given canonical type, can we safely copy a
1425 /// value out of it based on its initializer?
1426 static bool isConstantEmittableObjectType(QualType type) {
1427   assert(type.isCanonical());
1428   assert(!type->isReferenceType());
1429 
1430   // Must be const-qualified but non-volatile.
1431   Qualifiers qs = type.getLocalQualifiers();
1432   if (!qs.hasConst() || qs.hasVolatile()) return false;
1433 
1434   // Otherwise, all object types satisfy this except C++ classes with
1435   // mutable subobjects or non-trivial copy/destroy behavior.
1436   if (const auto *RT = dyn_cast<RecordType>(type))
1437     if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1438       if (RD->hasMutableFields() || !RD->isTrivial())
1439         return false;
1440 
1441   return true;
1442 }
1443 
1444 /// Can we constant-emit a load of a reference to a variable of the
1445 /// given type?  This is different from predicates like
1446 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1447 /// in situations that don't necessarily satisfy the language's rules
1448 /// for this (e.g. C++'s ODR-use rules).  For example, we want to able
1449 /// to do this with const float variables even if those variables
1450 /// aren't marked 'constexpr'.
1451 enum ConstantEmissionKind {
1452   CEK_None,
1453   CEK_AsReferenceOnly,
1454   CEK_AsValueOrReference,
1455   CEK_AsValueOnly
1456 };
1457 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1458   type = type.getCanonicalType();
1459   if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1460     if (isConstantEmittableObjectType(ref->getPointeeType()))
1461       return CEK_AsValueOrReference;
1462     return CEK_AsReferenceOnly;
1463   }
1464   if (isConstantEmittableObjectType(type))
1465     return CEK_AsValueOnly;
1466   return CEK_None;
1467 }
1468 
1469 /// Try to emit a reference to the given value without producing it as
1470 /// an l-value.  This is just an optimization, but it avoids us needing
1471 /// to emit global copies of variables if they're named without triggering
1472 /// a formal use in a context where we can't emit a direct reference to them,
1473 /// for instance if a block or lambda or a member of a local class uses a
1474 /// const int variable or constexpr variable from an enclosing function.
1475 CodeGenFunction::ConstantEmission
1476 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1477   ValueDecl *value = refExpr->getDecl();
1478 
1479   // The value needs to be an enum constant or a constant variable.
1480   ConstantEmissionKind CEK;
1481   if (isa<ParmVarDecl>(value)) {
1482     CEK = CEK_None;
1483   } else if (auto *var = dyn_cast<VarDecl>(value)) {
1484     CEK = checkVarTypeForConstantEmission(var->getType());
1485   } else if (isa<EnumConstantDecl>(value)) {
1486     CEK = CEK_AsValueOnly;
1487   } else {
1488     CEK = CEK_None;
1489   }
1490   if (CEK == CEK_None) return ConstantEmission();
1491 
1492   Expr::EvalResult result;
1493   bool resultIsReference;
1494   QualType resultType;
1495 
1496   // It's best to evaluate all the way as an r-value if that's permitted.
1497   if (CEK != CEK_AsReferenceOnly &&
1498       refExpr->EvaluateAsRValue(result, getContext())) {
1499     resultIsReference = false;
1500     resultType = refExpr->getType();
1501 
1502   // Otherwise, try to evaluate as an l-value.
1503   } else if (CEK != CEK_AsValueOnly &&
1504              refExpr->EvaluateAsLValue(result, getContext())) {
1505     resultIsReference = true;
1506     resultType = value->getType();
1507 
1508   // Failure.
1509   } else {
1510     return ConstantEmission();
1511   }
1512 
1513   // In any case, if the initializer has side-effects, abandon ship.
1514   if (result.HasSideEffects)
1515     return ConstantEmission();
1516 
1517   // In CUDA/HIP device compilation, a lambda may capture a reference variable
1518   // referencing a global host variable by copy. In this case the lambda should
1519   // make a copy of the value of the global host variable. The DRE of the
1520   // captured reference variable cannot be emitted as load from the host
1521   // global variable as compile time constant, since the host variable is not
1522   // accessible on device. The DRE of the captured reference variable has to be
1523   // loaded from captures.
1524   if (CGM.getLangOpts().CUDAIsDevice && result.Val.isLValue() &&
1525       refExpr->refersToEnclosingVariableOrCapture()) {
1526     auto *MD = dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl);
1527     if (MD && MD->getParent()->isLambda() &&
1528         MD->getOverloadedOperator() == OO_Call) {
1529       const APValue::LValueBase &base = result.Val.getLValueBase();
1530       if (const ValueDecl *D = base.dyn_cast<const ValueDecl *>()) {
1531         if (const VarDecl *VD = dyn_cast<const VarDecl>(D)) {
1532           if (!VD->hasAttr<CUDADeviceAttr>()) {
1533             return ConstantEmission();
1534           }
1535         }
1536       }
1537     }
1538   }
1539 
1540   // Emit as a constant.
1541   auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1542                                                result.Val, resultType);
1543 
1544   // Make sure we emit a debug reference to the global variable.
1545   // This should probably fire even for
1546   if (isa<VarDecl>(value)) {
1547     if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1548       EmitDeclRefExprDbgValue(refExpr, result.Val);
1549   } else {
1550     assert(isa<EnumConstantDecl>(value));
1551     EmitDeclRefExprDbgValue(refExpr, result.Val);
1552   }
1553 
1554   // If we emitted a reference constant, we need to dereference that.
1555   if (resultIsReference)
1556     return ConstantEmission::forReference(C);
1557 
1558   return ConstantEmission::forValue(C);
1559 }
1560 
1561 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF,
1562                                                         const MemberExpr *ME) {
1563   if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1564     // Try to emit static variable member expressions as DREs.
1565     return DeclRefExpr::Create(
1566         CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD,
1567         /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1568         ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1569   }
1570   return nullptr;
1571 }
1572 
1573 CodeGenFunction::ConstantEmission
1574 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
1575   if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1576     return tryEmitAsConstant(DRE);
1577   return ConstantEmission();
1578 }
1579 
1580 llvm::Value *CodeGenFunction::emitScalarConstant(
1581     const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1582   assert(Constant && "not a constant");
1583   if (Constant.isReference())
1584     return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1585                             E->getExprLoc())
1586         .getScalarVal();
1587   return Constant.getValue();
1588 }
1589 
1590 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1591                                                SourceLocation Loc) {
1592   return EmitLoadOfScalar(lvalue.getAddress(*this), lvalue.isVolatile(),
1593                           lvalue.getType(), Loc, lvalue.getBaseInfo(),
1594                           lvalue.getTBAAInfo(), lvalue.isNontemporal());
1595 }
1596 
1597 static bool hasBooleanRepresentation(QualType Ty) {
1598   if (Ty->isBooleanType())
1599     return true;
1600 
1601   if (const EnumType *ET = Ty->getAs<EnumType>())
1602     return ET->getDecl()->getIntegerType()->isBooleanType();
1603 
1604   if (const AtomicType *AT = Ty->getAs<AtomicType>())
1605     return hasBooleanRepresentation(AT->getValueType());
1606 
1607   return false;
1608 }
1609 
1610 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1611                             llvm::APInt &Min, llvm::APInt &End,
1612                             bool StrictEnums, bool IsBool) {
1613   const EnumType *ET = Ty->getAs<EnumType>();
1614   bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1615                                 ET && !ET->getDecl()->isFixed();
1616   if (!IsBool && !IsRegularCPlusPlusEnum)
1617     return false;
1618 
1619   if (IsBool) {
1620     Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1621     End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1622   } else {
1623     const EnumDecl *ED = ET->getDecl();
1624     llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1625     unsigned Bitwidth = LTy->getScalarSizeInBits();
1626     unsigned NumNegativeBits = ED->getNumNegativeBits();
1627     unsigned NumPositiveBits = ED->getNumPositiveBits();
1628 
1629     if (NumNegativeBits) {
1630       unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1631       assert(NumBits <= Bitwidth);
1632       End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1633       Min = -End;
1634     } else {
1635       assert(NumPositiveBits <= Bitwidth);
1636       End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1637       Min = llvm::APInt::getZero(Bitwidth);
1638     }
1639   }
1640   return true;
1641 }
1642 
1643 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1644   llvm::APInt Min, End;
1645   if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1646                        hasBooleanRepresentation(Ty)))
1647     return nullptr;
1648 
1649   llvm::MDBuilder MDHelper(getLLVMContext());
1650   return MDHelper.createRange(Min, End);
1651 }
1652 
1653 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1654                                            SourceLocation Loc) {
1655   bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1656   bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1657   if (!HasBoolCheck && !HasEnumCheck)
1658     return false;
1659 
1660   bool IsBool = hasBooleanRepresentation(Ty) ||
1661                 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1662   bool NeedsBoolCheck = HasBoolCheck && IsBool;
1663   bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1664   if (!NeedsBoolCheck && !NeedsEnumCheck)
1665     return false;
1666 
1667   // Single-bit booleans don't need to be checked. Special-case this to avoid
1668   // a bit width mismatch when handling bitfield values. This is handled by
1669   // EmitFromMemory for the non-bitfield case.
1670   if (IsBool &&
1671       cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1672     return false;
1673 
1674   llvm::APInt Min, End;
1675   if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1676     return true;
1677 
1678   auto &Ctx = getLLVMContext();
1679   SanitizerScope SanScope(this);
1680   llvm::Value *Check;
1681   --End;
1682   if (!Min) {
1683     Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1684   } else {
1685     llvm::Value *Upper =
1686         Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1687     llvm::Value *Lower =
1688         Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1689     Check = Builder.CreateAnd(Upper, Lower);
1690   }
1691   llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1692                                   EmitCheckTypeDescriptor(Ty)};
1693   SanitizerMask Kind =
1694       NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1695   EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1696             StaticArgs, EmitCheckValue(Value));
1697   return true;
1698 }
1699 
1700 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1701                                                QualType Ty,
1702                                                SourceLocation Loc,
1703                                                LValueBaseInfo BaseInfo,
1704                                                TBAAAccessInfo TBAAInfo,
1705                                                bool isNontemporal) {
1706   if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1707     // For better performance, handle vector loads differently.
1708     if (Ty->isVectorType()) {
1709       const llvm::Type *EltTy = Addr.getElementType();
1710 
1711       const auto *VTy = cast<llvm::FixedVectorType>(EltTy);
1712 
1713       // Handle vectors of size 3 like size 4 for better performance.
1714       if (VTy->getNumElements() == 3) {
1715 
1716         // Bitcast to vec4 type.
1717         auto *vec4Ty = llvm::FixedVectorType::get(VTy->getElementType(), 4);
1718         Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1719         // Now load value.
1720         llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1721 
1722         // Shuffle vector to get vec3.
1723         V = Builder.CreateShuffleVector(V, ArrayRef<int>{0, 1, 2},
1724                                         "extractVec");
1725         return EmitFromMemory(V, Ty);
1726       }
1727     }
1728   }
1729 
1730   // Atomic operations have to be done on integral types.
1731   LValue AtomicLValue =
1732       LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1733   if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1734     return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1735   }
1736 
1737   llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1738   if (isNontemporal) {
1739     llvm::MDNode *Node = llvm::MDNode::get(
1740         Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1741     Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1742   }
1743 
1744   CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1745 
1746   if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1747     // In order to prevent the optimizer from throwing away the check, don't
1748     // attach range metadata to the load.
1749   } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1750     if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1751       Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1752 
1753   return EmitFromMemory(Load, Ty);
1754 }
1755 
1756 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1757   // Bool has a different representation in memory than in registers.
1758   if (hasBooleanRepresentation(Ty)) {
1759     // This should really always be an i1, but sometimes it's already
1760     // an i8, and it's awkward to track those cases down.
1761     if (Value->getType()->isIntegerTy(1))
1762       return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1763     assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1764            "wrong value rep of bool");
1765   }
1766 
1767   return Value;
1768 }
1769 
1770 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1771   // Bool has a different representation in memory than in registers.
1772   if (hasBooleanRepresentation(Ty)) {
1773     assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1774            "wrong value rep of bool");
1775     return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1776   }
1777 
1778   return Value;
1779 }
1780 
1781 // Convert the pointer of \p Addr to a pointer to a vector (the value type of
1782 // MatrixType), if it points to a array (the memory type of MatrixType).
1783 static Address MaybeConvertMatrixAddress(Address Addr, CodeGenFunction &CGF,
1784                                          bool IsVector = true) {
1785   auto *ArrayTy = dyn_cast<llvm::ArrayType>(Addr.getElementType());
1786   if (ArrayTy && IsVector) {
1787     auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
1788                                                 ArrayTy->getNumElements());
1789 
1790     return Address(CGF.Builder.CreateElementBitCast(Addr, VectorTy));
1791   }
1792   auto *VectorTy = dyn_cast<llvm::VectorType>(Addr.getElementType());
1793   if (VectorTy && !IsVector) {
1794     auto *ArrayTy = llvm::ArrayType::get(
1795         VectorTy->getElementType(),
1796         cast<llvm::FixedVectorType>(VectorTy)->getNumElements());
1797 
1798     return Address(CGF.Builder.CreateElementBitCast(Addr, ArrayTy));
1799   }
1800 
1801   return Addr;
1802 }
1803 
1804 // Emit a store of a matrix LValue. This may require casting the original
1805 // pointer to memory address (ArrayType) to a pointer to the value type
1806 // (VectorType).
1807 static void EmitStoreOfMatrixScalar(llvm::Value *value, LValue lvalue,
1808                                     bool isInit, CodeGenFunction &CGF) {
1809   Address Addr = MaybeConvertMatrixAddress(lvalue.getAddress(CGF), CGF,
1810                                            value->getType()->isVectorTy());
1811   CGF.EmitStoreOfScalar(value, Addr, lvalue.isVolatile(), lvalue.getType(),
1812                         lvalue.getBaseInfo(), lvalue.getTBAAInfo(), isInit,
1813                         lvalue.isNontemporal());
1814 }
1815 
1816 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1817                                         bool Volatile, QualType Ty,
1818                                         LValueBaseInfo BaseInfo,
1819                                         TBAAAccessInfo TBAAInfo,
1820                                         bool isInit, bool isNontemporal) {
1821   if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1822     // Handle vectors differently to get better performance.
1823     if (Ty->isVectorType()) {
1824       llvm::Type *SrcTy = Value->getType();
1825       auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1826       // Handle vec3 special.
1827       if (VecTy && cast<llvm::FixedVectorType>(VecTy)->getNumElements() == 3) {
1828         // Our source is a vec3, do a shuffle vector to make it a vec4.
1829         Value = Builder.CreateShuffleVector(Value, ArrayRef<int>{0, 1, 2, -1},
1830                                             "extractVec");
1831         SrcTy = llvm::FixedVectorType::get(VecTy->getElementType(), 4);
1832       }
1833       if (Addr.getElementType() != SrcTy) {
1834         Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1835       }
1836     }
1837   }
1838 
1839   Value = EmitToMemory(Value, Ty);
1840 
1841   LValue AtomicLValue =
1842       LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1843   if (Ty->isAtomicType() ||
1844       (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1845     EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1846     return;
1847   }
1848 
1849   llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1850   if (isNontemporal) {
1851     llvm::MDNode *Node =
1852         llvm::MDNode::get(Store->getContext(),
1853                           llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1854     Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1855   }
1856 
1857   CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1858 }
1859 
1860 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1861                                         bool isInit) {
1862   if (lvalue.getType()->isConstantMatrixType()) {
1863     EmitStoreOfMatrixScalar(value, lvalue, isInit, *this);
1864     return;
1865   }
1866 
1867   EmitStoreOfScalar(value, lvalue.getAddress(*this), lvalue.isVolatile(),
1868                     lvalue.getType(), lvalue.getBaseInfo(),
1869                     lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1870 }
1871 
1872 // Emit a load of a LValue of matrix type. This may require casting the pointer
1873 // to memory address (ArrayType) to a pointer to the value type (VectorType).
1874 static RValue EmitLoadOfMatrixLValue(LValue LV, SourceLocation Loc,
1875                                      CodeGenFunction &CGF) {
1876   assert(LV.getType()->isConstantMatrixType());
1877   Address Addr = MaybeConvertMatrixAddress(LV.getAddress(CGF), CGF);
1878   LV.setAddress(Addr);
1879   return RValue::get(CGF.EmitLoadOfScalar(LV, Loc));
1880 }
1881 
1882 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1883 /// method emits the address of the lvalue, then loads the result as an rvalue,
1884 /// returning the rvalue.
1885 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1886   if (LV.isObjCWeak()) {
1887     // load of a __weak object.
1888     Address AddrWeakObj = LV.getAddress(*this);
1889     return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1890                                                              AddrWeakObj));
1891   }
1892   if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1893     // In MRC mode, we do a load+autorelease.
1894     if (!getLangOpts().ObjCAutoRefCount) {
1895       return RValue::get(EmitARCLoadWeak(LV.getAddress(*this)));
1896     }
1897 
1898     // In ARC mode, we load retained and then consume the value.
1899     llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress(*this));
1900     Object = EmitObjCConsumeObject(LV.getType(), Object);
1901     return RValue::get(Object);
1902   }
1903 
1904   if (LV.isSimple()) {
1905     assert(!LV.getType()->isFunctionType());
1906 
1907     if (LV.getType()->isConstantMatrixType())
1908       return EmitLoadOfMatrixLValue(LV, Loc, *this);
1909 
1910     // Everything needs a load.
1911     return RValue::get(EmitLoadOfScalar(LV, Loc));
1912   }
1913 
1914   if (LV.isVectorElt()) {
1915     llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1916                                               LV.isVolatileQualified());
1917     return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1918                                                     "vecext"));
1919   }
1920 
1921   // If this is a reference to a subset of the elements of a vector, either
1922   // shuffle the input or extract/insert them as appropriate.
1923   if (LV.isExtVectorElt()) {
1924     return EmitLoadOfExtVectorElementLValue(LV);
1925   }
1926 
1927   // Global Register variables always invoke intrinsics
1928   if (LV.isGlobalReg())
1929     return EmitLoadOfGlobalRegLValue(LV);
1930 
1931   if (LV.isMatrixElt()) {
1932     llvm::Value *Idx = LV.getMatrixIdx();
1933     if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
1934       const auto *const MatTy = LV.getType()->castAs<ConstantMatrixType>();
1935       llvm::MatrixBuilder<CGBuilderTy> MB(Builder);
1936       MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
1937     }
1938     llvm::LoadInst *Load =
1939         Builder.CreateLoad(LV.getMatrixAddress(), LV.isVolatileQualified());
1940     return RValue::get(Builder.CreateExtractElement(Load, Idx, "matrixext"));
1941   }
1942 
1943   assert(LV.isBitField() && "Unknown LValue type!");
1944   return EmitLoadOfBitfieldLValue(LV, Loc);
1945 }
1946 
1947 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1948                                                  SourceLocation Loc) {
1949   const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1950 
1951   // Get the output type.
1952   llvm::Type *ResLTy = ConvertType(LV.getType());
1953 
1954   Address Ptr = LV.getBitFieldAddress();
1955   llvm::Value *Val =
1956       Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1957 
1958   bool UseVolatile = LV.isVolatileQualified() &&
1959                      Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
1960   const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
1961   const unsigned StorageSize =
1962       UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
1963   if (Info.IsSigned) {
1964     assert(static_cast<unsigned>(Offset + Info.Size) <= StorageSize);
1965     unsigned HighBits = StorageSize - Offset - Info.Size;
1966     if (HighBits)
1967       Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1968     if (Offset + HighBits)
1969       Val = Builder.CreateAShr(Val, Offset + HighBits, "bf.ashr");
1970   } else {
1971     if (Offset)
1972       Val = Builder.CreateLShr(Val, Offset, "bf.lshr");
1973     if (static_cast<unsigned>(Offset) + Info.Size < StorageSize)
1974       Val = Builder.CreateAnd(
1975           Val, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), "bf.clear");
1976   }
1977   Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1978   EmitScalarRangeCheck(Val, LV.getType(), Loc);
1979   return RValue::get(Val);
1980 }
1981 
1982 // If this is a reference to a subset of the elements of a vector, create an
1983 // appropriate shufflevector.
1984 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1985   llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1986                                         LV.isVolatileQualified());
1987 
1988   const llvm::Constant *Elts = LV.getExtVectorElts();
1989 
1990   // If the result of the expression is a non-vector type, we must be extracting
1991   // a single element.  Just codegen as an extractelement.
1992   const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1993   if (!ExprVT) {
1994     unsigned InIdx = getAccessedFieldNo(0, Elts);
1995     llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1996     return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1997   }
1998 
1999   // Always use shuffle vector to try to retain the original program structure
2000   unsigned NumResultElts = ExprVT->getNumElements();
2001 
2002   SmallVector<int, 4> Mask;
2003   for (unsigned i = 0; i != NumResultElts; ++i)
2004     Mask.push_back(getAccessedFieldNo(i, Elts));
2005 
2006   Vec = Builder.CreateShuffleVector(Vec, Mask);
2007   return RValue::get(Vec);
2008 }
2009 
2010 /// Generates lvalue for partial ext_vector access.
2011 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
2012   Address VectorAddress = LV.getExtVectorAddress();
2013   QualType EQT = LV.getType()->castAs<VectorType>()->getElementType();
2014   llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
2015 
2016   Address CastToPointerElement =
2017     Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
2018                                  "conv.ptr.element");
2019 
2020   const llvm::Constant *Elts = LV.getExtVectorElts();
2021   unsigned ix = getAccessedFieldNo(0, Elts);
2022 
2023   Address VectorBasePtrPlusIx =
2024     Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
2025                                    "vector.elt");
2026 
2027   return VectorBasePtrPlusIx;
2028 }
2029 
2030 /// Load of global gamed gegisters are always calls to intrinsics.
2031 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
2032   assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
2033          "Bad type for register variable");
2034   llvm::MDNode *RegName = cast<llvm::MDNode>(
2035       cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
2036 
2037   // We accept integer and pointer types only
2038   llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
2039   llvm::Type *Ty = OrigTy;
2040   if (OrigTy->isPointerTy())
2041     Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2042   llvm::Type *Types[] = { Ty };
2043 
2044   llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
2045   llvm::Value *Call = Builder.CreateCall(
2046       F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
2047   if (OrigTy->isPointerTy())
2048     Call = Builder.CreateIntToPtr(Call, OrigTy);
2049   return RValue::get(Call);
2050 }
2051 
2052 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
2053 /// lvalue, where both are guaranteed to the have the same type, and that type
2054 /// is 'Ty'.
2055 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
2056                                              bool isInit) {
2057   if (!Dst.isSimple()) {
2058     if (Dst.isVectorElt()) {
2059       // Read/modify/write the vector, inserting the new element.
2060       llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
2061                                             Dst.isVolatileQualified());
2062       Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
2063                                         Dst.getVectorIdx(), "vecins");
2064       Builder.CreateStore(Vec, Dst.getVectorAddress(),
2065                           Dst.isVolatileQualified());
2066       return;
2067     }
2068 
2069     // If this is an update of extended vector elements, insert them as
2070     // appropriate.
2071     if (Dst.isExtVectorElt())
2072       return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
2073 
2074     if (Dst.isGlobalReg())
2075       return EmitStoreThroughGlobalRegLValue(Src, Dst);
2076 
2077     if (Dst.isMatrixElt()) {
2078       llvm::Value *Idx = Dst.getMatrixIdx();
2079       if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2080         const auto *const MatTy = Dst.getType()->castAs<ConstantMatrixType>();
2081         llvm::MatrixBuilder<CGBuilderTy> MB(Builder);
2082         MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2083       }
2084       llvm::Instruction *Load = Builder.CreateLoad(Dst.getMatrixAddress());
2085       llvm::Value *Vec =
2086           Builder.CreateInsertElement(Load, Src.getScalarVal(), Idx, "matins");
2087       Builder.CreateStore(Vec, Dst.getMatrixAddress(),
2088                           Dst.isVolatileQualified());
2089       return;
2090     }
2091 
2092     assert(Dst.isBitField() && "Unknown LValue type");
2093     return EmitStoreThroughBitfieldLValue(Src, Dst);
2094   }
2095 
2096   // There's special magic for assigning into an ARC-qualified l-value.
2097   if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
2098     switch (Lifetime) {
2099     case Qualifiers::OCL_None:
2100       llvm_unreachable("present but none");
2101 
2102     case Qualifiers::OCL_ExplicitNone:
2103       // nothing special
2104       break;
2105 
2106     case Qualifiers::OCL_Strong:
2107       if (isInit) {
2108         Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
2109         break;
2110       }
2111       EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
2112       return;
2113 
2114     case Qualifiers::OCL_Weak:
2115       if (isInit)
2116         // Initialize and then skip the primitive store.
2117         EmitARCInitWeak(Dst.getAddress(*this), Src.getScalarVal());
2118       else
2119         EmitARCStoreWeak(Dst.getAddress(*this), Src.getScalarVal(),
2120                          /*ignore*/ true);
2121       return;
2122 
2123     case Qualifiers::OCL_Autoreleasing:
2124       Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
2125                                                      Src.getScalarVal()));
2126       // fall into the normal path
2127       break;
2128     }
2129   }
2130 
2131   if (Dst.isObjCWeak() && !Dst.isNonGC()) {
2132     // load of a __weak object.
2133     Address LvalueDst = Dst.getAddress(*this);
2134     llvm::Value *src = Src.getScalarVal();
2135      CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
2136     return;
2137   }
2138 
2139   if (Dst.isObjCStrong() && !Dst.isNonGC()) {
2140     // load of a __strong object.
2141     Address LvalueDst = Dst.getAddress(*this);
2142     llvm::Value *src = Src.getScalarVal();
2143     if (Dst.isObjCIvar()) {
2144       assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2145       llvm::Type *ResultType = IntPtrTy;
2146       Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
2147       llvm::Value *RHS = dst.getPointer();
2148       RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2149       llvm::Value *LHS =
2150         Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2151                                "sub.ptr.lhs.cast");
2152       llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2153       CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2154                                               BytesBetween);
2155     } else if (Dst.isGlobalObjCRef()) {
2156       CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2157                                                 Dst.isThreadLocalRef());
2158     }
2159     else
2160       CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2161     return;
2162   }
2163 
2164   assert(Src.isScalar() && "Can't emit an agg store with this method");
2165   EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2166 }
2167 
2168 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
2169                                                      llvm::Value **Result) {
2170   const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2171   llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2172   Address Ptr = Dst.getBitFieldAddress();
2173 
2174   // Get the source value, truncated to the width of the bit-field.
2175   llvm::Value *SrcVal = Src.getScalarVal();
2176 
2177   // Cast the source to the storage type and shift it into place.
2178   SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2179                                  /*isSigned=*/false);
2180   llvm::Value *MaskedVal = SrcVal;
2181 
2182   const bool UseVolatile =
2183       CGM.getCodeGenOpts().AAPCSBitfieldWidth && Dst.isVolatileQualified() &&
2184       Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2185   const unsigned StorageSize =
2186       UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2187   const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2188   // See if there are other bits in the bitfield's storage we'll need to load
2189   // and mask together with source before storing.
2190   if (StorageSize != Info.Size) {
2191     assert(StorageSize > Info.Size && "Invalid bitfield size.");
2192     llvm::Value *Val =
2193         Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2194 
2195     // Mask the source value as needed.
2196     if (!hasBooleanRepresentation(Dst.getType()))
2197       SrcVal = Builder.CreateAnd(
2198           SrcVal, llvm::APInt::getLowBitsSet(StorageSize, Info.Size),
2199           "bf.value");
2200     MaskedVal = SrcVal;
2201     if (Offset)
2202       SrcVal = Builder.CreateShl(SrcVal, Offset, "bf.shl");
2203 
2204     // Mask out the original value.
2205     Val = Builder.CreateAnd(
2206         Val, ~llvm::APInt::getBitsSet(StorageSize, Offset, Offset + Info.Size),
2207         "bf.clear");
2208 
2209     // Or together the unchanged values and the source value.
2210     SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2211   } else {
2212     assert(Offset == 0);
2213     // According to the AACPS:
2214     // When a volatile bit-field is written, and its container does not overlap
2215     // with any non-bit-field member, its container must be read exactly once
2216     // and written exactly once using the access width appropriate to the type
2217     // of the container. The two accesses are not atomic.
2218     if (Dst.isVolatileQualified() && isAAPCS(CGM.getTarget()) &&
2219         CGM.getCodeGenOpts().ForceAAPCSBitfieldLoad)
2220       Builder.CreateLoad(Ptr, true, "bf.load");
2221   }
2222 
2223   // Write the new value back out.
2224   Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2225 
2226   // Return the new value of the bit-field, if requested.
2227   if (Result) {
2228     llvm::Value *ResultVal = MaskedVal;
2229 
2230     // Sign extend the value if needed.
2231     if (Info.IsSigned) {
2232       assert(Info.Size <= StorageSize);
2233       unsigned HighBits = StorageSize - Info.Size;
2234       if (HighBits) {
2235         ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2236         ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2237       }
2238     }
2239 
2240     ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2241                                       "bf.result.cast");
2242     *Result = EmitFromMemory(ResultVal, Dst.getType());
2243   }
2244 }
2245 
2246 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
2247                                                                LValue Dst) {
2248   // This access turns into a read/modify/write of the vector.  Load the input
2249   // value now.
2250   llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
2251                                         Dst.isVolatileQualified());
2252   const llvm::Constant *Elts = Dst.getExtVectorElts();
2253 
2254   llvm::Value *SrcVal = Src.getScalarVal();
2255 
2256   if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2257     unsigned NumSrcElts = VTy->getNumElements();
2258     unsigned NumDstElts =
2259         cast<llvm::FixedVectorType>(Vec->getType())->getNumElements();
2260     if (NumDstElts == NumSrcElts) {
2261       // Use shuffle vector is the src and destination are the same number of
2262       // elements and restore the vector mask since it is on the side it will be
2263       // stored.
2264       SmallVector<int, 4> Mask(NumDstElts);
2265       for (unsigned i = 0; i != NumSrcElts; ++i)
2266         Mask[getAccessedFieldNo(i, Elts)] = i;
2267 
2268       Vec = Builder.CreateShuffleVector(SrcVal, Mask);
2269     } else if (NumDstElts > NumSrcElts) {
2270       // Extended the source vector to the same length and then shuffle it
2271       // into the destination.
2272       // FIXME: since we're shuffling with undef, can we just use the indices
2273       //        into that?  This could be simpler.
2274       SmallVector<int, 4> ExtMask;
2275       for (unsigned i = 0; i != NumSrcElts; ++i)
2276         ExtMask.push_back(i);
2277       ExtMask.resize(NumDstElts, -1);
2278       llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, ExtMask);
2279       // build identity
2280       SmallVector<int, 4> Mask;
2281       for (unsigned i = 0; i != NumDstElts; ++i)
2282         Mask.push_back(i);
2283 
2284       // When the vector size is odd and .odd or .hi is used, the last element
2285       // of the Elts constant array will be one past the size of the vector.
2286       // Ignore the last element here, if it is greater than the mask size.
2287       if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2288         NumSrcElts--;
2289 
2290       // modify when what gets shuffled in
2291       for (unsigned i = 0; i != NumSrcElts; ++i)
2292         Mask[getAccessedFieldNo(i, Elts)] = i + NumDstElts;
2293       Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, Mask);
2294     } else {
2295       // We should never shorten the vector
2296       llvm_unreachable("unexpected shorten vector length");
2297     }
2298   } else {
2299     // If the Src is a scalar (not a vector) it must be updating one element.
2300     unsigned InIdx = getAccessedFieldNo(0, Elts);
2301     llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2302     Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2303   }
2304 
2305   Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
2306                       Dst.isVolatileQualified());
2307 }
2308 
2309 /// Store of global named registers are always calls to intrinsics.
2310 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
2311   assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2312          "Bad type for register variable");
2313   llvm::MDNode *RegName = cast<llvm::MDNode>(
2314       cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2315   assert(RegName && "Register LValue is not metadata");
2316 
2317   // We accept integer and pointer types only
2318   llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2319   llvm::Type *Ty = OrigTy;
2320   if (OrigTy->isPointerTy())
2321     Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2322   llvm::Type *Types[] = { Ty };
2323 
2324   llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2325   llvm::Value *Value = Src.getScalarVal();
2326   if (OrigTy->isPointerTy())
2327     Value = Builder.CreatePtrToInt(Value, Ty);
2328   Builder.CreateCall(
2329       F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2330 }
2331 
2332 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2333 // generating write-barries API. It is currently a global, ivar,
2334 // or neither.
2335 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2336                                  LValue &LV,
2337                                  bool IsMemberAccess=false) {
2338   if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2339     return;
2340 
2341   if (isa<ObjCIvarRefExpr>(E)) {
2342     QualType ExpTy = E->getType();
2343     if (IsMemberAccess && ExpTy->isPointerType()) {
2344       // If ivar is a structure pointer, assigning to field of
2345       // this struct follows gcc's behavior and makes it a non-ivar
2346       // writer-barrier conservatively.
2347       ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2348       if (ExpTy->isRecordType()) {
2349         LV.setObjCIvar(false);
2350         return;
2351       }
2352     }
2353     LV.setObjCIvar(true);
2354     auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2355     LV.setBaseIvarExp(Exp->getBase());
2356     LV.setObjCArray(E->getType()->isArrayType());
2357     return;
2358   }
2359 
2360   if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2361     if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2362       if (VD->hasGlobalStorage()) {
2363         LV.setGlobalObjCRef(true);
2364         LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2365       }
2366     }
2367     LV.setObjCArray(E->getType()->isArrayType());
2368     return;
2369   }
2370 
2371   if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2372     setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2373     return;
2374   }
2375 
2376   if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2377     setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2378     if (LV.isObjCIvar()) {
2379       // If cast is to a structure pointer, follow gcc's behavior and make it
2380       // a non-ivar write-barrier.
2381       QualType ExpTy = E->getType();
2382       if (ExpTy->isPointerType())
2383         ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2384       if (ExpTy->isRecordType())
2385         LV.setObjCIvar(false);
2386     }
2387     return;
2388   }
2389 
2390   if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2391     setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2392     return;
2393   }
2394 
2395   if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2396     setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2397     return;
2398   }
2399 
2400   if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2401     setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2402     return;
2403   }
2404 
2405   if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2406     setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2407     return;
2408   }
2409 
2410   if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2411     setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2412     if (LV.isObjCIvar() && !LV.isObjCArray())
2413       // Using array syntax to assigning to what an ivar points to is not
2414       // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2415       LV.setObjCIvar(false);
2416     else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2417       // Using array syntax to assigning to what global points to is not
2418       // same as assigning to the global itself. {id *G;} G[i] = 0;
2419       LV.setGlobalObjCRef(false);
2420     return;
2421   }
2422 
2423   if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2424     setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2425     // We don't know if member is an 'ivar', but this flag is looked at
2426     // only in the context of LV.isObjCIvar().
2427     LV.setObjCArray(E->getType()->isArrayType());
2428     return;
2429   }
2430 }
2431 
2432 static llvm::Value *
2433 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2434                                 llvm::Value *V, llvm::Type *IRType,
2435                                 StringRef Name = StringRef()) {
2436   unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2437   return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2438 }
2439 
2440 static LValue EmitThreadPrivateVarDeclLValue(
2441     CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2442     llvm::Type *RealVarTy, SourceLocation Loc) {
2443   if (CGF.CGM.getLangOpts().OpenMPIRBuilder)
2444     Addr = CodeGenFunction::OMPBuilderCBHelpers::getAddrOfThreadPrivate(
2445         CGF, VD, Addr, Loc);
2446   else
2447     Addr =
2448         CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2449 
2450   Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2451   return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2452 }
2453 
2454 static Address emitDeclTargetVarDeclLValue(CodeGenFunction &CGF,
2455                                            const VarDecl *VD, QualType T) {
2456   llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2457       OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2458   // Return an invalid address if variable is MT_To and unified
2459   // memory is not enabled. For all other cases: MT_Link and
2460   // MT_To with unified memory, return a valid address.
2461   if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2462                !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2463     return Address::invalid();
2464   assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2465           (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2466            CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2467          "Expected link clause OR to clause with unified memory enabled.");
2468   QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2469   Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2470   return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2471 }
2472 
2473 Address
2474 CodeGenFunction::EmitLoadOfReference(LValue RefLVal,
2475                                      LValueBaseInfo *PointeeBaseInfo,
2476                                      TBAAAccessInfo *PointeeTBAAInfo) {
2477   llvm::LoadInst *Load =
2478       Builder.CreateLoad(RefLVal.getAddress(*this), RefLVal.isVolatile());
2479   CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2480 
2481   QualType PointeeType = RefLVal.getType()->getPointeeType();
2482   CharUnits Align = CGM.getNaturalTypeAlignment(
2483       PointeeType, PointeeBaseInfo, PointeeTBAAInfo,
2484       /* forPointeeType= */ true);
2485   return Address(Load, ConvertTypeForMem(PointeeType), Align);
2486 }
2487 
2488 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) {
2489   LValueBaseInfo PointeeBaseInfo;
2490   TBAAAccessInfo PointeeTBAAInfo;
2491   Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2492                                             &PointeeTBAAInfo);
2493   return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2494                         PointeeBaseInfo, PointeeTBAAInfo);
2495 }
2496 
2497 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2498                                            const PointerType *PtrTy,
2499                                            LValueBaseInfo *BaseInfo,
2500                                            TBAAAccessInfo *TBAAInfo) {
2501   llvm::Value *Addr = Builder.CreateLoad(Ptr);
2502   return Address(Addr, CGM.getNaturalTypeAlignment(PtrTy->getPointeeType(),
2503                                                    BaseInfo, TBAAInfo,
2504                                                    /*forPointeeType=*/true));
2505 }
2506 
2507 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2508                                                 const PointerType *PtrTy) {
2509   LValueBaseInfo BaseInfo;
2510   TBAAAccessInfo TBAAInfo;
2511   Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2512   return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2513 }
2514 
2515 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2516                                       const Expr *E, const VarDecl *VD) {
2517   QualType T = E->getType();
2518 
2519   // If it's thread_local, emit a call to its wrapper function instead.
2520   if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2521       CGF.CGM.getCXXABI().usesThreadWrapperFunction(VD))
2522     return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2523   // Check if the variable is marked as declare target with link clause in
2524   // device codegen.
2525   if (CGF.getLangOpts().OpenMPIsDevice) {
2526     Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2527     if (Addr.isValid())
2528       return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2529   }
2530 
2531   llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2532   llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2533   V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2534   CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2535   Address Addr(V, RealVarTy, Alignment);
2536   // Emit reference to the private copy of the variable if it is an OpenMP
2537   // threadprivate variable.
2538   if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2539       VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2540     return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2541                                           E->getExprLoc());
2542   }
2543   LValue LV = VD->getType()->isReferenceType() ?
2544       CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2545                                     AlignmentSource::Decl) :
2546       CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2547   setObjCGCLValueClass(CGF.getContext(), E, LV);
2548   return LV;
2549 }
2550 
2551 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2552                                                GlobalDecl GD) {
2553   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2554   if (FD->hasAttr<WeakRefAttr>()) {
2555     ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2556     return aliasee.getPointer();
2557   }
2558 
2559   llvm::Constant *V = CGM.GetAddrOfFunction(GD);
2560   if (!FD->hasPrototype()) {
2561     if (const FunctionProtoType *Proto =
2562             FD->getType()->getAs<FunctionProtoType>()) {
2563       // Ugly case: for a K&R-style definition, the type of the definition
2564       // isn't the same as the type of a use.  Correct for this with a
2565       // bitcast.
2566       QualType NoProtoType =
2567           CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2568       NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2569       V = llvm::ConstantExpr::getBitCast(V,
2570                                       CGM.getTypes().ConvertType(NoProtoType));
2571     }
2572   }
2573   return V;
2574 }
2575 
2576 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, const Expr *E,
2577                                      GlobalDecl GD) {
2578   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2579   llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, GD);
2580   CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2581   return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2582                             AlignmentSource::Decl);
2583 }
2584 
2585 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2586                                       llvm::Value *ThisValue) {
2587   QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2588   LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2589   return CGF.EmitLValueForField(LV, FD);
2590 }
2591 
2592 /// Named Registers are named metadata pointing to the register name
2593 /// which will be read from/written to as an argument to the intrinsic
2594 /// @llvm.read/write_register.
2595 /// So far, only the name is being passed down, but other options such as
2596 /// register type, allocation type or even optimization options could be
2597 /// passed down via the metadata node.
2598 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2599   SmallString<64> Name("llvm.named.register.");
2600   AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2601   assert(Asm->getLabel().size() < 64-Name.size() &&
2602       "Register name too big");
2603   Name.append(Asm->getLabel());
2604   llvm::NamedMDNode *M =
2605     CGM.getModule().getOrInsertNamedMetadata(Name);
2606   if (M->getNumOperands() == 0) {
2607     llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2608                                               Asm->getLabel());
2609     llvm::Metadata *Ops[] = {Str};
2610     M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2611   }
2612 
2613   CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2614 
2615   llvm::Value *Ptr =
2616     llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2617   return LValue::MakeGlobalReg(Ptr, Alignment, VD->getType());
2618 }
2619 
2620 /// Determine whether we can emit a reference to \p VD from the current
2621 /// context, despite not necessarily having seen an odr-use of the variable in
2622 /// this context.
2623 static bool canEmitSpuriousReferenceToVariable(CodeGenFunction &CGF,
2624                                                const DeclRefExpr *E,
2625                                                const VarDecl *VD,
2626                                                bool IsConstant) {
2627   // For a variable declared in an enclosing scope, do not emit a spurious
2628   // reference even if we have a capture, as that will emit an unwarranted
2629   // reference to our capture state, and will likely generate worse code than
2630   // emitting a local copy.
2631   if (E->refersToEnclosingVariableOrCapture())
2632     return false;
2633 
2634   // For a local declaration declared in this function, we can always reference
2635   // it even if we don't have an odr-use.
2636   if (VD->hasLocalStorage()) {
2637     return VD->getDeclContext() ==
2638            dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2639   }
2640 
2641   // For a global declaration, we can emit a reference to it if we know
2642   // for sure that we are able to emit a definition of it.
2643   VD = VD->getDefinition(CGF.getContext());
2644   if (!VD)
2645     return false;
2646 
2647   // Don't emit a spurious reference if it might be to a variable that only
2648   // exists on a different device / target.
2649   // FIXME: This is unnecessarily broad. Check whether this would actually be a
2650   // cross-target reference.
2651   if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2652       CGF.getLangOpts().OpenCL) {
2653     return false;
2654   }
2655 
2656   // We can emit a spurious reference only if the linkage implies that we'll
2657   // be emitting a non-interposable symbol that will be retained until link
2658   // time.
2659   switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2660   case llvm::GlobalValue::ExternalLinkage:
2661   case llvm::GlobalValue::LinkOnceODRLinkage:
2662   case llvm::GlobalValue::WeakODRLinkage:
2663   case llvm::GlobalValue::InternalLinkage:
2664   case llvm::GlobalValue::PrivateLinkage:
2665     return true;
2666   default:
2667     return false;
2668   }
2669 }
2670 
2671 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2672   const NamedDecl *ND = E->getDecl();
2673   QualType T = E->getType();
2674 
2675   assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2676          "should not emit an unevaluated operand");
2677 
2678   if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2679     // Global Named registers access via intrinsics only
2680     if (VD->getStorageClass() == SC_Register &&
2681         VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2682       return EmitGlobalNamedRegister(VD, CGM);
2683 
2684     // If this DeclRefExpr does not constitute an odr-use of the variable,
2685     // we're not permitted to emit a reference to it in general, and it might
2686     // not be captured if capture would be necessary for a use. Emit the
2687     // constant value directly instead.
2688     if (E->isNonOdrUse() == NOUR_Constant &&
2689         (VD->getType()->isReferenceType() ||
2690          !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2691       VD->getAnyInitializer(VD);
2692       llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2693           E->getLocation(), *VD->evaluateValue(), VD->getType());
2694       assert(Val && "failed to emit constant expression");
2695 
2696       Address Addr = Address::invalid();
2697       if (!VD->getType()->isReferenceType()) {
2698         // Spill the constant value to a global.
2699         Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2700                                            getContext().getDeclAlign(VD));
2701         llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
2702         auto *PTy = llvm::PointerType::get(
2703             VarTy, getContext().getTargetAddressSpace(VD->getType()));
2704         if (PTy != Addr.getType())
2705           Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy);
2706       } else {
2707         // Should we be using the alignment of the constant pointer we emitted?
2708         CharUnits Alignment =
2709             CGM.getNaturalTypeAlignment(E->getType(),
2710                                         /* BaseInfo= */ nullptr,
2711                                         /* TBAAInfo= */ nullptr,
2712                                         /* forPointeeType= */ true);
2713         Addr = Address(Val, ConvertTypeForMem(E->getType()), Alignment);
2714       }
2715       return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2716     }
2717 
2718     // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2719 
2720     // Check for captured variables.
2721     if (E->refersToEnclosingVariableOrCapture()) {
2722       VD = VD->getCanonicalDecl();
2723       if (auto *FD = LambdaCaptureFields.lookup(VD))
2724         return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2725       if (CapturedStmtInfo) {
2726         auto I = LocalDeclMap.find(VD);
2727         if (I != LocalDeclMap.end()) {
2728           LValue CapLVal;
2729           if (VD->getType()->isReferenceType())
2730             CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(),
2731                                                 AlignmentSource::Decl);
2732           else
2733             CapLVal = MakeAddrLValue(I->second, T);
2734           // Mark lvalue as nontemporal if the variable is marked as nontemporal
2735           // in simd context.
2736           if (getLangOpts().OpenMP &&
2737               CGM.getOpenMPRuntime().isNontemporalDecl(VD))
2738             CapLVal.setNontemporal(/*Value=*/true);
2739           return CapLVal;
2740         }
2741         LValue CapLVal =
2742             EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2743                                     CapturedStmtInfo->getContextValue());
2744         CapLVal = MakeAddrLValue(
2745             Address(CapLVal.getPointer(*this), getContext().getDeclAlign(VD)),
2746             CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl),
2747             CapLVal.getTBAAInfo());
2748         // Mark lvalue as nontemporal if the variable is marked as nontemporal
2749         // in simd context.
2750         if (getLangOpts().OpenMP &&
2751             CGM.getOpenMPRuntime().isNontemporalDecl(VD))
2752           CapLVal.setNontemporal(/*Value=*/true);
2753         return CapLVal;
2754       }
2755 
2756       assert(isa<BlockDecl>(CurCodeDecl));
2757       Address addr = GetAddrOfBlockDecl(VD);
2758       return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2759     }
2760   }
2761 
2762   // FIXME: We should be able to assert this for FunctionDecls as well!
2763   // FIXME: We should be able to assert this for all DeclRefExprs, not just
2764   // those with a valid source location.
2765   assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2766           !E->getLocation().isValid()) &&
2767          "Should not use decl without marking it used!");
2768 
2769   if (ND->hasAttr<WeakRefAttr>()) {
2770     const auto *VD = cast<ValueDecl>(ND);
2771     ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2772     return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2773   }
2774 
2775   if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2776     // Check if this is a global variable.
2777     if (VD->hasLinkage() || VD->isStaticDataMember())
2778       return EmitGlobalVarDeclLValue(*this, E, VD);
2779 
2780     Address addr = Address::invalid();
2781 
2782     // The variable should generally be present in the local decl map.
2783     auto iter = LocalDeclMap.find(VD);
2784     if (iter != LocalDeclMap.end()) {
2785       addr = iter->second;
2786 
2787     // Otherwise, it might be static local we haven't emitted yet for
2788     // some reason; most likely, because it's in an outer function.
2789     } else if (VD->isStaticLocal()) {
2790       llvm::Constant *var = CGM.getOrCreateStaticVarDecl(
2791           *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false));
2792       addr = Address(
2793           var, ConvertTypeForMem(VD->getType()), getContext().getDeclAlign(VD));
2794 
2795     // No other cases for now.
2796     } else {
2797       llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2798     }
2799 
2800 
2801     // Check for OpenMP threadprivate variables.
2802     if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2803         VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2804       return EmitThreadPrivateVarDeclLValue(
2805           *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2806           E->getExprLoc());
2807     }
2808 
2809     // Drill into block byref variables.
2810     bool isBlockByref = VD->isEscapingByref();
2811     if (isBlockByref) {
2812       addr = emitBlockByrefAddress(addr, VD);
2813     }
2814 
2815     // Drill into reference types.
2816     LValue LV = VD->getType()->isReferenceType() ?
2817         EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
2818         MakeAddrLValue(addr, T, AlignmentSource::Decl);
2819 
2820     bool isLocalStorage = VD->hasLocalStorage();
2821 
2822     bool NonGCable = isLocalStorage &&
2823                      !VD->getType()->isReferenceType() &&
2824                      !isBlockByref;
2825     if (NonGCable) {
2826       LV.getQuals().removeObjCGCAttr();
2827       LV.setNonGC(true);
2828     }
2829 
2830     bool isImpreciseLifetime =
2831       (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2832     if (isImpreciseLifetime)
2833       LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2834     setObjCGCLValueClass(getContext(), E, LV);
2835     return LV;
2836   }
2837 
2838   if (const auto *FD = dyn_cast<FunctionDecl>(ND)) {
2839     LValue LV = EmitFunctionDeclLValue(*this, E, FD);
2840 
2841     // Emit debuginfo for the function declaration if the target wants to.
2842     if (getContext().getTargetInfo().allowDebugInfoForExternalRef()) {
2843       if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) {
2844         auto *Fn =
2845             cast<llvm::Function>(LV.getPointer(*this)->stripPointerCasts());
2846         if (!Fn->getSubprogram())
2847           DI->EmitFunctionDecl(FD, FD->getLocation(), T, Fn);
2848       }
2849     }
2850 
2851     return LV;
2852   }
2853 
2854   // FIXME: While we're emitting a binding from an enclosing scope, all other
2855   // DeclRefExprs we see should be implicitly treated as if they also refer to
2856   // an enclosing scope.
2857   if (const auto *BD = dyn_cast<BindingDecl>(ND))
2858     return EmitLValue(BD->getBinding());
2859 
2860   // We can form DeclRefExprs naming GUID declarations when reconstituting
2861   // non-type template parameters into expressions.
2862   if (const auto *GD = dyn_cast<MSGuidDecl>(ND))
2863     return MakeAddrLValue(CGM.GetAddrOfMSGuidDecl(GD), T,
2864                           AlignmentSource::Decl);
2865 
2866   if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND))
2867     return MakeAddrLValue(CGM.GetAddrOfTemplateParamObject(TPO), T,
2868                           AlignmentSource::Decl);
2869 
2870   llvm_unreachable("Unhandled DeclRefExpr");
2871 }
2872 
2873 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2874   // __extension__ doesn't affect lvalue-ness.
2875   if (E->getOpcode() == UO_Extension)
2876     return EmitLValue(E->getSubExpr());
2877 
2878   QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2879   switch (E->getOpcode()) {
2880   default: llvm_unreachable("Unknown unary operator lvalue!");
2881   case UO_Deref: {
2882     QualType T = E->getSubExpr()->getType()->getPointeeType();
2883     assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2884 
2885     LValueBaseInfo BaseInfo;
2886     TBAAAccessInfo TBAAInfo;
2887     Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2888                                             &TBAAInfo);
2889     LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2890     LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2891 
2892     // We should not generate __weak write barrier on indirect reference
2893     // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2894     // But, we continue to generate __strong write barrier on indirect write
2895     // into a pointer to object.
2896     if (getLangOpts().ObjC &&
2897         getLangOpts().getGC() != LangOptions::NonGC &&
2898         LV.isObjCWeak())
2899       LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2900     return LV;
2901   }
2902   case UO_Real:
2903   case UO_Imag: {
2904     LValue LV = EmitLValue(E->getSubExpr());
2905     assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2906 
2907     // __real is valid on scalars.  This is a faster way of testing that.
2908     // __imag can only produce an rvalue on scalars.
2909     if (E->getOpcode() == UO_Real &&
2910         !LV.getAddress(*this).getElementType()->isStructTy()) {
2911       assert(E->getSubExpr()->getType()->isArithmeticType());
2912       return LV;
2913     }
2914 
2915     QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2916 
2917     Address Component =
2918         (E->getOpcode() == UO_Real
2919              ? emitAddrOfRealComponent(LV.getAddress(*this), LV.getType())
2920              : emitAddrOfImagComponent(LV.getAddress(*this), LV.getType()));
2921     LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2922                                    CGM.getTBAAInfoForSubobject(LV, T));
2923     ElemLV.getQuals().addQualifiers(LV.getQuals());
2924     return ElemLV;
2925   }
2926   case UO_PreInc:
2927   case UO_PreDec: {
2928     LValue LV = EmitLValue(E->getSubExpr());
2929     bool isInc = E->getOpcode() == UO_PreInc;
2930 
2931     if (E->getType()->isAnyComplexType())
2932       EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2933     else
2934       EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2935     return LV;
2936   }
2937   }
2938 }
2939 
2940 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2941   return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2942                         E->getType(), AlignmentSource::Decl);
2943 }
2944 
2945 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2946   return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2947                         E->getType(), AlignmentSource::Decl);
2948 }
2949 
2950 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2951   auto SL = E->getFunctionName();
2952   assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2953   StringRef FnName = CurFn->getName();
2954   if (FnName.startswith("\01"))
2955     FnName = FnName.substr(1);
2956   StringRef NameItems[] = {
2957       PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName};
2958   std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2959   if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2960     std::string Name = std::string(SL->getString());
2961     if (!Name.empty()) {
2962       unsigned Discriminator =
2963           CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2964       if (Discriminator)
2965         Name += "_" + Twine(Discriminator + 1).str();
2966       auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2967       return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2968     } else {
2969       auto C =
2970           CGM.GetAddrOfConstantCString(std::string(FnName), GVName.c_str());
2971       return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2972     }
2973   }
2974   auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2975   return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2976 }
2977 
2978 /// Emit a type description suitable for use by a runtime sanitizer library. The
2979 /// format of a type descriptor is
2980 ///
2981 /// \code
2982 ///   { i16 TypeKind, i16 TypeInfo }
2983 /// \endcode
2984 ///
2985 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2986 /// integer, 1 for a floating point value, and -1 for anything else.
2987 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2988   // Only emit each type's descriptor once.
2989   if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2990     return C;
2991 
2992   uint16_t TypeKind = -1;
2993   uint16_t TypeInfo = 0;
2994 
2995   if (T->isIntegerType()) {
2996     TypeKind = 0;
2997     TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2998                (T->isSignedIntegerType() ? 1 : 0);
2999   } else if (T->isFloatingType()) {
3000     TypeKind = 1;
3001     TypeInfo = getContext().getTypeSize(T);
3002   }
3003 
3004   // Format the type name as if for a diagnostic, including quotes and
3005   // optionally an 'aka'.
3006   SmallString<32> Buffer;
3007   CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
3008                                     (intptr_t)T.getAsOpaquePtr(),
3009                                     StringRef(), StringRef(), None, Buffer,
3010                                     None);
3011 
3012   llvm::Constant *Components[] = {
3013     Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
3014     llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
3015   };
3016   llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
3017 
3018   auto *GV = new llvm::GlobalVariable(
3019       CGM.getModule(), Descriptor->getType(),
3020       /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
3021   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3022   CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
3023 
3024   // Remember the descriptor for this type.
3025   CGM.setTypeDescriptorInMap(T, GV);
3026 
3027   return GV;
3028 }
3029 
3030 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
3031   llvm::Type *TargetTy = IntPtrTy;
3032 
3033   if (V->getType() == TargetTy)
3034     return V;
3035 
3036   // Floating-point types which fit into intptr_t are bitcast to integers
3037   // and then passed directly (after zero-extension, if necessary).
3038   if (V->getType()->isFloatingPointTy()) {
3039     unsigned Bits = V->getType()->getPrimitiveSizeInBits().getFixedSize();
3040     if (Bits <= TargetTy->getIntegerBitWidth())
3041       V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
3042                                                          Bits));
3043   }
3044 
3045   // Integers which fit in intptr_t are zero-extended and passed directly.
3046   if (V->getType()->isIntegerTy() &&
3047       V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
3048     return Builder.CreateZExt(V, TargetTy);
3049 
3050   // Pointers are passed directly, everything else is passed by address.
3051   if (!V->getType()->isPointerTy()) {
3052     Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
3053     Builder.CreateStore(V, Ptr);
3054     V = Ptr.getPointer();
3055   }
3056   return Builder.CreatePtrToInt(V, TargetTy);
3057 }
3058 
3059 /// Emit a representation of a SourceLocation for passing to a handler
3060 /// in a sanitizer runtime library. The format for this data is:
3061 /// \code
3062 ///   struct SourceLocation {
3063 ///     const char *Filename;
3064 ///     int32_t Line, Column;
3065 ///   };
3066 /// \endcode
3067 /// For an invalid SourceLocation, the Filename pointer is null.
3068 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
3069   llvm::Constant *Filename;
3070   int Line, Column;
3071 
3072   PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
3073   if (PLoc.isValid()) {
3074     StringRef FilenameString = PLoc.getFilename();
3075 
3076     int PathComponentsToStrip =
3077         CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
3078     if (PathComponentsToStrip < 0) {
3079       assert(PathComponentsToStrip != INT_MIN);
3080       int PathComponentsToKeep = -PathComponentsToStrip;
3081       auto I = llvm::sys::path::rbegin(FilenameString);
3082       auto E = llvm::sys::path::rend(FilenameString);
3083       while (I != E && --PathComponentsToKeep)
3084         ++I;
3085 
3086       FilenameString = FilenameString.substr(I - E);
3087     } else if (PathComponentsToStrip > 0) {
3088       auto I = llvm::sys::path::begin(FilenameString);
3089       auto E = llvm::sys::path::end(FilenameString);
3090       while (I != E && PathComponentsToStrip--)
3091         ++I;
3092 
3093       if (I != E)
3094         FilenameString =
3095             FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
3096       else
3097         FilenameString = llvm::sys::path::filename(FilenameString);
3098     }
3099 
3100     auto FilenameGV =
3101         CGM.GetAddrOfConstantCString(std::string(FilenameString), ".src");
3102     CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
3103                           cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
3104     Filename = FilenameGV.getPointer();
3105     Line = PLoc.getLine();
3106     Column = PLoc.getColumn();
3107   } else {
3108     Filename = llvm::Constant::getNullValue(Int8PtrTy);
3109     Line = Column = 0;
3110   }
3111 
3112   llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
3113                             Builder.getInt32(Column)};
3114 
3115   return llvm::ConstantStruct::getAnon(Data);
3116 }
3117 
3118 namespace {
3119 /// Specify under what conditions this check can be recovered
3120 enum class CheckRecoverableKind {
3121   /// Always terminate program execution if this check fails.
3122   Unrecoverable,
3123   /// Check supports recovering, runtime has both fatal (noreturn) and
3124   /// non-fatal handlers for this check.
3125   Recoverable,
3126   /// Runtime conditionally aborts, always need to support recovery.
3127   AlwaysRecoverable
3128 };
3129 }
3130 
3131 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
3132   assert(Kind.countPopulation() == 1);
3133   if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
3134     return CheckRecoverableKind::AlwaysRecoverable;
3135   else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
3136     return CheckRecoverableKind::Unrecoverable;
3137   else
3138     return CheckRecoverableKind::Recoverable;
3139 }
3140 
3141 namespace {
3142 struct SanitizerHandlerInfo {
3143   char const *const Name;
3144   unsigned Version;
3145 };
3146 }
3147 
3148 const SanitizerHandlerInfo SanitizerHandlers[] = {
3149 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
3150     LIST_SANITIZER_CHECKS
3151 #undef SANITIZER_CHECK
3152 };
3153 
3154 static void emitCheckHandlerCall(CodeGenFunction &CGF,
3155                                  llvm::FunctionType *FnType,
3156                                  ArrayRef<llvm::Value *> FnArgs,
3157                                  SanitizerHandler CheckHandler,
3158                                  CheckRecoverableKind RecoverKind, bool IsFatal,
3159                                  llvm::BasicBlock *ContBB) {
3160   assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
3161   Optional<ApplyDebugLocation> DL;
3162   if (!CGF.Builder.getCurrentDebugLocation()) {
3163     // Ensure that the call has at least an artificial debug location.
3164     DL.emplace(CGF, SourceLocation());
3165   }
3166   bool NeedsAbortSuffix =
3167       IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
3168   bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
3169   const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
3170   const StringRef CheckName = CheckInfo.Name;
3171   std::string FnName = "__ubsan_handle_" + CheckName.str();
3172   if (CheckInfo.Version && !MinimalRuntime)
3173     FnName += "_v" + llvm::utostr(CheckInfo.Version);
3174   if (MinimalRuntime)
3175     FnName += "_minimal";
3176   if (NeedsAbortSuffix)
3177     FnName += "_abort";
3178   bool MayReturn =
3179       !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
3180 
3181   llvm::AttrBuilder B(CGF.getLLVMContext());
3182   if (!MayReturn) {
3183     B.addAttribute(llvm::Attribute::NoReturn)
3184         .addAttribute(llvm::Attribute::NoUnwind);
3185   }
3186   B.addAttribute(llvm::Attribute::UWTable);
3187 
3188   llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
3189       FnType, FnName,
3190       llvm::AttributeList::get(CGF.getLLVMContext(),
3191                                llvm::AttributeList::FunctionIndex, B),
3192       /*Local=*/true);
3193   llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
3194   if (!MayReturn) {
3195     HandlerCall->setDoesNotReturn();
3196     CGF.Builder.CreateUnreachable();
3197   } else {
3198     CGF.Builder.CreateBr(ContBB);
3199   }
3200 }
3201 
3202 void CodeGenFunction::EmitCheck(
3203     ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3204     SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3205     ArrayRef<llvm::Value *> DynamicArgs) {
3206   assert(IsSanitizerScope);
3207   assert(Checked.size() > 0);
3208   assert(CheckHandler >= 0 &&
3209          size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3210   const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3211 
3212   llvm::Value *FatalCond = nullptr;
3213   llvm::Value *RecoverableCond = nullptr;
3214   llvm::Value *TrapCond = nullptr;
3215   for (int i = 0, n = Checked.size(); i < n; ++i) {
3216     llvm::Value *Check = Checked[i].first;
3217     // -fsanitize-trap= overrides -fsanitize-recover=.
3218     llvm::Value *&Cond =
3219         CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3220             ? TrapCond
3221             : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3222                   ? RecoverableCond
3223                   : FatalCond;
3224     Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3225   }
3226 
3227   if (TrapCond)
3228     EmitTrapCheck(TrapCond, CheckHandler);
3229   if (!FatalCond && !RecoverableCond)
3230     return;
3231 
3232   llvm::Value *JointCond;
3233   if (FatalCond && RecoverableCond)
3234     JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3235   else
3236     JointCond = FatalCond ? FatalCond : RecoverableCond;
3237   assert(JointCond);
3238 
3239   CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3240   assert(SanOpts.has(Checked[0].second));
3241 #ifndef NDEBUG
3242   for (int i = 1, n = Checked.size(); i < n; ++i) {
3243     assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3244            "All recoverable kinds in a single check must be same!");
3245     assert(SanOpts.has(Checked[i].second));
3246   }
3247 #endif
3248 
3249   llvm::BasicBlock *Cont = createBasicBlock("cont");
3250   llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3251   llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3252   // Give hint that we very much don't expect to execute the handler
3253   // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3254   llvm::MDBuilder MDHelper(getLLVMContext());
3255   llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3256   Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3257   EmitBlock(Handlers);
3258 
3259   // Handler functions take an i8* pointing to the (handler-specific) static
3260   // information block, followed by a sequence of intptr_t arguments
3261   // representing operand values.
3262   SmallVector<llvm::Value *, 4> Args;
3263   SmallVector<llvm::Type *, 4> ArgTypes;
3264   if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3265     Args.reserve(DynamicArgs.size() + 1);
3266     ArgTypes.reserve(DynamicArgs.size() + 1);
3267 
3268     // Emit handler arguments and create handler function type.
3269     if (!StaticArgs.empty()) {
3270       llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3271       auto *InfoPtr =
3272           new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3273                                    llvm::GlobalVariable::PrivateLinkage, Info);
3274       InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3275       CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3276       Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3277       ArgTypes.push_back(Int8PtrTy);
3278     }
3279 
3280     for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3281       Args.push_back(EmitCheckValue(DynamicArgs[i]));
3282       ArgTypes.push_back(IntPtrTy);
3283     }
3284   }
3285 
3286   llvm::FunctionType *FnType =
3287     llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3288 
3289   if (!FatalCond || !RecoverableCond) {
3290     // Simple case: we need to generate a single handler call, either
3291     // fatal, or non-fatal.
3292     emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3293                          (FatalCond != nullptr), Cont);
3294   } else {
3295     // Emit two handler calls: first one for set of unrecoverable checks,
3296     // another one for recoverable.
3297     llvm::BasicBlock *NonFatalHandlerBB =
3298         createBasicBlock("non_fatal." + CheckName);
3299     llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3300     Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3301     EmitBlock(FatalHandlerBB);
3302     emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3303                          NonFatalHandlerBB);
3304     EmitBlock(NonFatalHandlerBB);
3305     emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3306                          Cont);
3307   }
3308 
3309   EmitBlock(Cont);
3310 }
3311 
3312 void CodeGenFunction::EmitCfiSlowPathCheck(
3313     SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3314     llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3315   llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3316 
3317   llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3318   llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3319 
3320   llvm::MDBuilder MDHelper(getLLVMContext());
3321   llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3322   BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3323 
3324   EmitBlock(CheckBB);
3325 
3326   bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3327 
3328   llvm::CallInst *CheckCall;
3329   llvm::FunctionCallee SlowPathFn;
3330   if (WithDiag) {
3331     llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3332     auto *InfoPtr =
3333         new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3334                                  llvm::GlobalVariable::PrivateLinkage, Info);
3335     InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3336     CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3337 
3338     SlowPathFn = CGM.getModule().getOrInsertFunction(
3339         "__cfi_slowpath_diag",
3340         llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3341                                 false));
3342     CheckCall = Builder.CreateCall(
3343         SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3344   } else {
3345     SlowPathFn = CGM.getModule().getOrInsertFunction(
3346         "__cfi_slowpath",
3347         llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3348     CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3349   }
3350 
3351   CGM.setDSOLocal(
3352       cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3353   CheckCall->setDoesNotThrow();
3354 
3355   EmitBlock(Cont);
3356 }
3357 
3358 // Emit a stub for __cfi_check function so that the linker knows about this
3359 // symbol in LTO mode.
3360 void CodeGenFunction::EmitCfiCheckStub() {
3361   llvm::Module *M = &CGM.getModule();
3362   auto &Ctx = M->getContext();
3363   llvm::Function *F = llvm::Function::Create(
3364       llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3365       llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3366   CGM.setDSOLocal(F);
3367   llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3368   // FIXME: consider emitting an intrinsic call like
3369   // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3370   // which can be lowered in CrossDSOCFI pass to the actual contents of
3371   // __cfi_check. This would allow inlining of __cfi_check calls.
3372   llvm::CallInst::Create(
3373       llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3374   llvm::ReturnInst::Create(Ctx, nullptr, BB);
3375 }
3376 
3377 // This function is basically a switch over the CFI failure kind, which is
3378 // extracted from CFICheckFailData (1st function argument). Each case is either
3379 // llvm.trap or a call to one of the two runtime handlers, based on
3380 // -fsanitize-trap and -fsanitize-recover settings.  Default case (invalid
3381 // failure kind) traps, but this should really never happen.  CFICheckFailData
3382 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3383 // check kind; in this case __cfi_check_fail traps as well.
3384 void CodeGenFunction::EmitCfiCheckFail() {
3385   SanitizerScope SanScope(this);
3386   FunctionArgList Args;
3387   ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
3388                             ImplicitParamDecl::Other);
3389   ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
3390                             ImplicitParamDecl::Other);
3391   Args.push_back(&ArgData);
3392   Args.push_back(&ArgAddr);
3393 
3394   const CGFunctionInfo &FI =
3395     CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
3396 
3397   llvm::Function *F = llvm::Function::Create(
3398       llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3399       llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3400 
3401   CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3402   CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F);
3403   F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3404 
3405   StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3406                 SourceLocation());
3407 
3408   // This function is not affected by NoSanitizeList. This function does
3409   // not have a source location, but "src:*" would still apply. Revert any
3410   // changes to SanOpts made in StartFunction.
3411   SanOpts = CGM.getLangOpts().Sanitize;
3412 
3413   llvm::Value *Data =
3414       EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3415                        CGM.getContext().VoidPtrTy, ArgData.getLocation());
3416   llvm::Value *Addr =
3417       EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3418                        CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3419 
3420   // Data == nullptr means the calling module has trap behaviour for this check.
3421   llvm::Value *DataIsNotNullPtr =
3422       Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3423   EmitTrapCheck(DataIsNotNullPtr, SanitizerHandler::CFICheckFail);
3424 
3425   llvm::StructType *SourceLocationTy =
3426       llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3427   llvm::StructType *CfiCheckFailDataTy =
3428       llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3429 
3430   llvm::Value *V = Builder.CreateConstGEP2_32(
3431       CfiCheckFailDataTy,
3432       Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3433       0);
3434   Address CheckKindAddr(V, getIntAlign());
3435   llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3436 
3437   llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3438       CGM.getLLVMContext(),
3439       llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3440   llvm::Value *ValidVtable = Builder.CreateZExt(
3441       Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3442                          {Addr, AllVtables}),
3443       IntPtrTy);
3444 
3445   const std::pair<int, SanitizerMask> CheckKinds[] = {
3446       {CFITCK_VCall, SanitizerKind::CFIVCall},
3447       {CFITCK_NVCall, SanitizerKind::CFINVCall},
3448       {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3449       {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3450       {CFITCK_ICall, SanitizerKind::CFIICall}};
3451 
3452   SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
3453   for (auto CheckKindMaskPair : CheckKinds) {
3454     int Kind = CheckKindMaskPair.first;
3455     SanitizerMask Mask = CheckKindMaskPair.second;
3456     llvm::Value *Cond =
3457         Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3458     if (CGM.getLangOpts().Sanitize.has(Mask))
3459       EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3460                 {Data, Addr, ValidVtable});
3461     else
3462       EmitTrapCheck(Cond, SanitizerHandler::CFICheckFail);
3463   }
3464 
3465   FinishFunction();
3466   // The only reference to this function will be created during LTO link.
3467   // Make sure it survives until then.
3468   CGM.addUsedGlobal(F);
3469 }
3470 
3471 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) {
3472   if (SanOpts.has(SanitizerKind::Unreachable)) {
3473     SanitizerScope SanScope(this);
3474     EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3475                              SanitizerKind::Unreachable),
3476               SanitizerHandler::BuiltinUnreachable,
3477               EmitCheckSourceLocation(Loc), None);
3478   }
3479   Builder.CreateUnreachable();
3480 }
3481 
3482 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked,
3483                                     SanitizerHandler CheckHandlerID) {
3484   llvm::BasicBlock *Cont = createBasicBlock("cont");
3485 
3486   // If we're optimizing, collapse all calls to trap down to just one per
3487   // check-type per function to save on code size.
3488   if (TrapBBs.size() <= CheckHandlerID)
3489     TrapBBs.resize(CheckHandlerID + 1);
3490   llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID];
3491 
3492   if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3493     TrapBB = createBasicBlock("trap");
3494     Builder.CreateCondBr(Checked, Cont, TrapBB);
3495     EmitBlock(TrapBB);
3496 
3497     llvm::CallInst *TrapCall =
3498         Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
3499                            llvm::ConstantInt::get(CGM.Int8Ty, CheckHandlerID));
3500 
3501     if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3502       auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3503                                     CGM.getCodeGenOpts().TrapFuncName);
3504       TrapCall->addFnAttr(A);
3505     }
3506     TrapCall->setDoesNotReturn();
3507     TrapCall->setDoesNotThrow();
3508     Builder.CreateUnreachable();
3509   } else {
3510     auto Call = TrapBB->begin();
3511     assert(isa<llvm::CallInst>(Call) && "Expected call in trap BB");
3512 
3513     Call->applyMergedLocation(Call->getDebugLoc(),
3514                               Builder.getCurrentDebugLocation());
3515     Builder.CreateCondBr(Checked, Cont, TrapBB);
3516   }
3517 
3518   EmitBlock(Cont);
3519 }
3520 
3521 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
3522   llvm::CallInst *TrapCall =
3523       Builder.CreateCall(CGM.getIntrinsic(IntrID));
3524 
3525   if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3526     auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3527                                   CGM.getCodeGenOpts().TrapFuncName);
3528     TrapCall->addFnAttr(A);
3529   }
3530 
3531   return TrapCall;
3532 }
3533 
3534 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
3535                                                  LValueBaseInfo *BaseInfo,
3536                                                  TBAAAccessInfo *TBAAInfo) {
3537   assert(E->getType()->isArrayType() &&
3538          "Array to pointer decay must have array source type!");
3539 
3540   // Expressions of array type can't be bitfields or vector elements.
3541   LValue LV = EmitLValue(E);
3542   Address Addr = LV.getAddress(*this);
3543 
3544   // If the array type was an incomplete type, we need to make sure
3545   // the decay ends up being the right type.
3546   llvm::Type *NewTy = ConvertType(E->getType());
3547   Addr = Builder.CreateElementBitCast(Addr, NewTy);
3548 
3549   // Note that VLA pointers are always decayed, so we don't need to do
3550   // anything here.
3551   if (!E->getType()->isVariableArrayType()) {
3552     assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3553            "Expected pointer to array");
3554     Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3555   }
3556 
3557   // The result of this decay conversion points to an array element within the
3558   // base lvalue. However, since TBAA currently does not support representing
3559   // accesses to elements of member arrays, we conservatively represent accesses
3560   // to the pointee object as if it had no any base lvalue specified.
3561   // TODO: Support TBAA for member arrays.
3562   QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
3563   if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3564   if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3565 
3566   return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3567 }
3568 
3569 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3570 /// array to pointer, return the array subexpression.
3571 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3572   // If this isn't just an array->pointer decay, bail out.
3573   const auto *CE = dyn_cast<CastExpr>(E);
3574   if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3575     return nullptr;
3576 
3577   // If this is a decay from variable width array, bail out.
3578   const Expr *SubExpr = CE->getSubExpr();
3579   if (SubExpr->getType()->isVariableArrayType())
3580     return nullptr;
3581 
3582   return SubExpr;
3583 }
3584 
3585 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3586                                           llvm::Type *elemType,
3587                                           llvm::Value *ptr,
3588                                           ArrayRef<llvm::Value*> indices,
3589                                           bool inbounds,
3590                                           bool signedIndices,
3591                                           SourceLocation loc,
3592                                     const llvm::Twine &name = "arrayidx") {
3593   if (inbounds) {
3594     return CGF.EmitCheckedInBoundsGEP(elemType, ptr, indices, signedIndices,
3595                                       CodeGenFunction::NotSubtraction, loc,
3596                                       name);
3597   } else {
3598     return CGF.Builder.CreateGEP(elemType, ptr, indices, name);
3599   }
3600 }
3601 
3602 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3603                                       llvm::Value *idx,
3604                                       CharUnits eltSize) {
3605   // If we have a constant index, we can use the exact offset of the
3606   // element we're accessing.
3607   if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3608     CharUnits offset = constantIdx->getZExtValue() * eltSize;
3609     return arrayAlign.alignmentAtOffset(offset);
3610 
3611   // Otherwise, use the worst-case alignment for any element.
3612   } else {
3613     return arrayAlign.alignmentOfArrayElement(eltSize);
3614   }
3615 }
3616 
3617 static QualType getFixedSizeElementType(const ASTContext &ctx,
3618                                         const VariableArrayType *vla) {
3619   QualType eltType;
3620   do {
3621     eltType = vla->getElementType();
3622   } while ((vla = ctx.getAsVariableArrayType(eltType)));
3623   return eltType;
3624 }
3625 
3626 /// Given an array base, check whether its member access belongs to a record
3627 /// with preserve_access_index attribute or not.
3628 static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
3629   if (!ArrayBase || !CGF.getDebugInfo())
3630     return false;
3631 
3632   // Only support base as either a MemberExpr or DeclRefExpr.
3633   // DeclRefExpr to cover cases like:
3634   //    struct s { int a; int b[10]; };
3635   //    struct s *p;
3636   //    p[1].a
3637   // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
3638   // p->b[5] is a MemberExpr example.
3639   const Expr *E = ArrayBase->IgnoreImpCasts();
3640   if (const auto *ME = dyn_cast<MemberExpr>(E))
3641     return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3642 
3643   if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
3644     const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
3645     if (!VarDef)
3646       return false;
3647 
3648     const auto *PtrT = VarDef->getType()->getAs<PointerType>();
3649     if (!PtrT)
3650       return false;
3651 
3652     const auto *PointeeT = PtrT->getPointeeType()
3653                              ->getUnqualifiedDesugaredType();
3654     if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
3655       return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3656     return false;
3657   }
3658 
3659   return false;
3660 }
3661 
3662 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3663                                      ArrayRef<llvm::Value *> indices,
3664                                      QualType eltType, bool inbounds,
3665                                      bool signedIndices, SourceLocation loc,
3666                                      QualType *arrayType = nullptr,
3667                                      const Expr *Base = nullptr,
3668                                      const llvm::Twine &name = "arrayidx") {
3669   // All the indices except that last must be zero.
3670 #ifndef NDEBUG
3671   for (auto idx : indices.drop_back())
3672     assert(isa<llvm::ConstantInt>(idx) &&
3673            cast<llvm::ConstantInt>(idx)->isZero());
3674 #endif
3675 
3676   // Determine the element size of the statically-sized base.  This is
3677   // the thing that the indices are expressed in terms of.
3678   if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3679     eltType = getFixedSizeElementType(CGF.getContext(), vla);
3680   }
3681 
3682   // We can use that to compute the best alignment of the element.
3683   CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3684   CharUnits eltAlign =
3685     getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3686 
3687   llvm::Value *eltPtr;
3688   auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3689   if (!LastIndex ||
3690       (!CGF.IsInPreservedAIRegion && !IsPreserveAIArrayBase(CGF, Base))) {
3691     eltPtr = emitArraySubscriptGEP(
3692         CGF, addr.getElementType(), addr.getPointer(), indices, inbounds,
3693         signedIndices, loc, name);
3694   } else {
3695     // Remember the original array subscript for bpf target
3696     unsigned idx = LastIndex->getZExtValue();
3697     llvm::DIType *DbgInfo = nullptr;
3698     if (arrayType)
3699       DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
3700     eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getElementType(),
3701                                                         addr.getPointer(),
3702                                                         indices.size() - 1,
3703                                                         idx, DbgInfo);
3704   }
3705 
3706   return Address(eltPtr, CGF.ConvertTypeForMem(eltType), eltAlign);
3707 }
3708 
3709 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3710                                                bool Accessed) {
3711   // The index must always be an integer, which is not an aggregate.  Emit it
3712   // in lexical order (this complexity is, sadly, required by C++17).
3713   llvm::Value *IdxPre =
3714       (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3715   bool SignedIndices = false;
3716   auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3717     auto *Idx = IdxPre;
3718     if (E->getLHS() != E->getIdx()) {
3719       assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3720       Idx = EmitScalarExpr(E->getIdx());
3721     }
3722 
3723     QualType IdxTy = E->getIdx()->getType();
3724     bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3725     SignedIndices |= IdxSigned;
3726 
3727     if (SanOpts.has(SanitizerKind::ArrayBounds))
3728       EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3729 
3730     // Extend or truncate the index type to 32 or 64-bits.
3731     if (Promote && Idx->getType() != IntPtrTy)
3732       Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3733 
3734     return Idx;
3735   };
3736   IdxPre = nullptr;
3737 
3738   // If the base is a vector type, then we are forming a vector element lvalue
3739   // with this subscript.
3740   if (E->getBase()->getType()->isVectorType() &&
3741       !isa<ExtVectorElementExpr>(E->getBase())) {
3742     // Emit the vector as an lvalue to get its address.
3743     LValue LHS = EmitLValue(E->getBase());
3744     auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3745     assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3746     return LValue::MakeVectorElt(LHS.getAddress(*this), Idx,
3747                                  E->getBase()->getType(), LHS.getBaseInfo(),
3748                                  TBAAAccessInfo());
3749   }
3750 
3751   // All the other cases basically behave like simple offsetting.
3752 
3753   // Handle the extvector case we ignored above.
3754   if (isa<ExtVectorElementExpr>(E->getBase())) {
3755     LValue LV = EmitLValue(E->getBase());
3756     auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3757     Address Addr = EmitExtVectorElementLValue(LV);
3758 
3759     QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3760     Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3761                                  SignedIndices, E->getExprLoc());
3762     return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3763                           CGM.getTBAAInfoForSubobject(LV, EltType));
3764   }
3765 
3766   LValueBaseInfo EltBaseInfo;
3767   TBAAAccessInfo EltTBAAInfo;
3768   Address Addr = Address::invalid();
3769   if (const VariableArrayType *vla =
3770            getContext().getAsVariableArrayType(E->getType())) {
3771     // The base must be a pointer, which is not an aggregate.  Emit
3772     // it.  It needs to be emitted first in case it's what captures
3773     // the VLA bounds.
3774     Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3775     auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3776 
3777     // The element count here is the total number of non-VLA elements.
3778     llvm::Value *numElements = getVLASize(vla).NumElts;
3779 
3780     // Effectively, the multiply by the VLA size is part of the GEP.
3781     // GEP indexes are signed, and scaling an index isn't permitted to
3782     // signed-overflow, so we use the same semantics for our explicit
3783     // multiply.  We suppress this if overflow is not undefined behavior.
3784     if (getLangOpts().isSignedOverflowDefined()) {
3785       Idx = Builder.CreateMul(Idx, numElements);
3786     } else {
3787       Idx = Builder.CreateNSWMul(Idx, numElements);
3788     }
3789 
3790     Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3791                                  !getLangOpts().isSignedOverflowDefined(),
3792                                  SignedIndices, E->getExprLoc());
3793 
3794   } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3795     // Indexing over an interface, as in "NSString *P; P[4];"
3796 
3797     // Emit the base pointer.
3798     Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3799     auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3800 
3801     CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3802     llvm::Value *InterfaceSizeVal =
3803         llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3804 
3805     llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3806 
3807     // We don't necessarily build correct LLVM struct types for ObjC
3808     // interfaces, so we can't rely on GEP to do this scaling
3809     // correctly, so we need to cast to i8*.  FIXME: is this actually
3810     // true?  A lot of other things in the fragile ABI would break...
3811     llvm::Type *OrigBaseTy = Addr.getType();
3812     Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3813 
3814     // Do the GEP.
3815     CharUnits EltAlign =
3816       getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3817     llvm::Value *EltPtr =
3818         emitArraySubscriptGEP(*this, Addr.getElementType(), Addr.getPointer(),
3819                               ScaledIdx, false, SignedIndices, E->getExprLoc());
3820     Addr = Address(EltPtr, EltAlign);
3821 
3822     // Cast back.
3823     Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3824   } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3825     // If this is A[i] where A is an array, the frontend will have decayed the
3826     // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
3827     // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3828     // "gep x, i" here.  Emit one "gep A, 0, i".
3829     assert(Array->getType()->isArrayType() &&
3830            "Array to pointer decay must have array source type!");
3831     LValue ArrayLV;
3832     // For simple multidimensional array indexing, set the 'accessed' flag for
3833     // better bounds-checking of the base expression.
3834     if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3835       ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3836     else
3837       ArrayLV = EmitLValue(Array);
3838     auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3839 
3840     // Propagate the alignment from the array itself to the result.
3841     QualType arrayType = Array->getType();
3842     Addr = emitArraySubscriptGEP(
3843         *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
3844         E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3845         E->getExprLoc(), &arrayType, E->getBase());
3846     EltBaseInfo = ArrayLV.getBaseInfo();
3847     EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3848   } else {
3849     // The base must be a pointer; emit it with an estimate of its alignment.
3850     Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3851     auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3852     QualType ptrType = E->getBase()->getType();
3853     Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3854                                  !getLangOpts().isSignedOverflowDefined(),
3855                                  SignedIndices, E->getExprLoc(), &ptrType,
3856                                  E->getBase());
3857   }
3858 
3859   LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3860 
3861   if (getLangOpts().ObjC &&
3862       getLangOpts().getGC() != LangOptions::NonGC) {
3863     LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3864     setObjCGCLValueClass(getContext(), E, LV);
3865   }
3866   return LV;
3867 }
3868 
3869 LValue CodeGenFunction::EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E) {
3870   assert(
3871       !E->isIncomplete() &&
3872       "incomplete matrix subscript expressions should be rejected during Sema");
3873   LValue Base = EmitLValue(E->getBase());
3874   llvm::Value *RowIdx = EmitScalarExpr(E->getRowIdx());
3875   llvm::Value *ColIdx = EmitScalarExpr(E->getColumnIdx());
3876   llvm::Value *NumRows = Builder.getIntN(
3877       RowIdx->getType()->getScalarSizeInBits(),
3878       E->getBase()->getType()->castAs<ConstantMatrixType>()->getNumRows());
3879   llvm::Value *FinalIdx =
3880       Builder.CreateAdd(Builder.CreateMul(ColIdx, NumRows), RowIdx);
3881   return LValue::MakeMatrixElt(
3882       MaybeConvertMatrixAddress(Base.getAddress(*this), *this), FinalIdx,
3883       E->getBase()->getType(), Base.getBaseInfo(), TBAAAccessInfo());
3884 }
3885 
3886 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3887                                        LValueBaseInfo &BaseInfo,
3888                                        TBAAAccessInfo &TBAAInfo,
3889                                        QualType BaseTy, QualType ElTy,
3890                                        bool IsLowerBound) {
3891   LValue BaseLVal;
3892   if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3893     BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3894     if (BaseTy->isArrayType()) {
3895       Address Addr = BaseLVal.getAddress(CGF);
3896       BaseInfo = BaseLVal.getBaseInfo();
3897 
3898       // If the array type was an incomplete type, we need to make sure
3899       // the decay ends up being the right type.
3900       llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3901       Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3902 
3903       // Note that VLA pointers are always decayed, so we don't need to do
3904       // anything here.
3905       if (!BaseTy->isVariableArrayType()) {
3906         assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3907                "Expected pointer to array");
3908         Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3909       }
3910 
3911       return CGF.Builder.CreateElementBitCast(Addr,
3912                                               CGF.ConvertTypeForMem(ElTy));
3913     }
3914     LValueBaseInfo TypeBaseInfo;
3915     TBAAAccessInfo TypeTBAAInfo;
3916     CharUnits Align =
3917         CGF.CGM.getNaturalTypeAlignment(ElTy, &TypeBaseInfo, &TypeTBAAInfo);
3918     BaseInfo.mergeForCast(TypeBaseInfo);
3919     TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3920     return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress(CGF)), Align);
3921   }
3922   return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3923 }
3924 
3925 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3926                                                 bool IsLowerBound) {
3927   QualType BaseTy = OMPArraySectionExpr::getBaseOriginalType(E->getBase());
3928   QualType ResultExprTy;
3929   if (auto *AT = getContext().getAsArrayType(BaseTy))
3930     ResultExprTy = AT->getElementType();
3931   else
3932     ResultExprTy = BaseTy->getPointeeType();
3933   llvm::Value *Idx = nullptr;
3934   if (IsLowerBound || E->getColonLocFirst().isInvalid()) {
3935     // Requesting lower bound or upper bound, but without provided length and
3936     // without ':' symbol for the default length -> length = 1.
3937     // Idx = LowerBound ?: 0;
3938     if (auto *LowerBound = E->getLowerBound()) {
3939       Idx = Builder.CreateIntCast(
3940           EmitScalarExpr(LowerBound), IntPtrTy,
3941           LowerBound->getType()->hasSignedIntegerRepresentation());
3942     } else
3943       Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3944   } else {
3945     // Try to emit length or lower bound as constant. If this is possible, 1
3946     // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3947     // IR (LB + Len) - 1.
3948     auto &C = CGM.getContext();
3949     auto *Length = E->getLength();
3950     llvm::APSInt ConstLength;
3951     if (Length) {
3952       // Idx = LowerBound + Length - 1;
3953       if (Optional<llvm::APSInt> CL = Length->getIntegerConstantExpr(C)) {
3954         ConstLength = CL->zextOrTrunc(PointerWidthInBits);
3955         Length = nullptr;
3956       }
3957       auto *LowerBound = E->getLowerBound();
3958       llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3959       if (LowerBound) {
3960         if (Optional<llvm::APSInt> LB = LowerBound->getIntegerConstantExpr(C)) {
3961           ConstLowerBound = LB->zextOrTrunc(PointerWidthInBits);
3962           LowerBound = nullptr;
3963         }
3964       }
3965       if (!Length)
3966         --ConstLength;
3967       else if (!LowerBound)
3968         --ConstLowerBound;
3969 
3970       if (Length || LowerBound) {
3971         auto *LowerBoundVal =
3972             LowerBound
3973                 ? Builder.CreateIntCast(
3974                       EmitScalarExpr(LowerBound), IntPtrTy,
3975                       LowerBound->getType()->hasSignedIntegerRepresentation())
3976                 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3977         auto *LengthVal =
3978             Length
3979                 ? Builder.CreateIntCast(
3980                       EmitScalarExpr(Length), IntPtrTy,
3981                       Length->getType()->hasSignedIntegerRepresentation())
3982                 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3983         Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3984                                 /*HasNUW=*/false,
3985                                 !getLangOpts().isSignedOverflowDefined());
3986         if (Length && LowerBound) {
3987           Idx = Builder.CreateSub(
3988               Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3989               /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3990         }
3991       } else
3992         Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3993     } else {
3994       // Idx = ArraySize - 1;
3995       QualType ArrayTy = BaseTy->isPointerType()
3996                              ? E->getBase()->IgnoreParenImpCasts()->getType()
3997                              : BaseTy;
3998       if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3999         Length = VAT->getSizeExpr();
4000         if (Optional<llvm::APSInt> L = Length->getIntegerConstantExpr(C)) {
4001           ConstLength = *L;
4002           Length = nullptr;
4003         }
4004       } else {
4005         auto *CAT = C.getAsConstantArrayType(ArrayTy);
4006         ConstLength = CAT->getSize();
4007       }
4008       if (Length) {
4009         auto *LengthVal = Builder.CreateIntCast(
4010             EmitScalarExpr(Length), IntPtrTy,
4011             Length->getType()->hasSignedIntegerRepresentation());
4012         Idx = Builder.CreateSub(
4013             LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
4014             /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
4015       } else {
4016         ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
4017         --ConstLength;
4018         Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
4019       }
4020     }
4021   }
4022   assert(Idx);
4023 
4024   Address EltPtr = Address::invalid();
4025   LValueBaseInfo BaseInfo;
4026   TBAAAccessInfo TBAAInfo;
4027   if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
4028     // The base must be a pointer, which is not an aggregate.  Emit
4029     // it.  It needs to be emitted first in case it's what captures
4030     // the VLA bounds.
4031     Address Base =
4032         emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
4033                                 BaseTy, VLA->getElementType(), IsLowerBound);
4034     // The element count here is the total number of non-VLA elements.
4035     llvm::Value *NumElements = getVLASize(VLA).NumElts;
4036 
4037     // Effectively, the multiply by the VLA size is part of the GEP.
4038     // GEP indexes are signed, and scaling an index isn't permitted to
4039     // signed-overflow, so we use the same semantics for our explicit
4040     // multiply.  We suppress this if overflow is not undefined behavior.
4041     if (getLangOpts().isSignedOverflowDefined())
4042       Idx = Builder.CreateMul(Idx, NumElements);
4043     else
4044       Idx = Builder.CreateNSWMul(Idx, NumElements);
4045     EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
4046                                    !getLangOpts().isSignedOverflowDefined(),
4047                                    /*signedIndices=*/false, E->getExprLoc());
4048   } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4049     // If this is A[i] where A is an array, the frontend will have decayed the
4050     // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
4051     // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4052     // "gep x, i" here.  Emit one "gep A, 0, i".
4053     assert(Array->getType()->isArrayType() &&
4054            "Array to pointer decay must have array source type!");
4055     LValue ArrayLV;
4056     // For simple multidimensional array indexing, set the 'accessed' flag for
4057     // better bounds-checking of the base expression.
4058     if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4059       ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4060     else
4061       ArrayLV = EmitLValue(Array);
4062 
4063     // Propagate the alignment from the array itself to the result.
4064     EltPtr = emitArraySubscriptGEP(
4065         *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
4066         ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
4067         /*signedIndices=*/false, E->getExprLoc());
4068     BaseInfo = ArrayLV.getBaseInfo();
4069     TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
4070   } else {
4071     Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
4072                                            TBAAInfo, BaseTy, ResultExprTy,
4073                                            IsLowerBound);
4074     EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
4075                                    !getLangOpts().isSignedOverflowDefined(),
4076                                    /*signedIndices=*/false, E->getExprLoc());
4077   }
4078 
4079   return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
4080 }
4081 
4082 LValue CodeGenFunction::
4083 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
4084   // Emit the base vector as an l-value.
4085   LValue Base;
4086 
4087   // ExtVectorElementExpr's base can either be a vector or pointer to vector.
4088   if (E->isArrow()) {
4089     // If it is a pointer to a vector, emit the address and form an lvalue with
4090     // it.
4091     LValueBaseInfo BaseInfo;
4092     TBAAAccessInfo TBAAInfo;
4093     Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
4094     const auto *PT = E->getBase()->getType()->castAs<PointerType>();
4095     Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
4096     Base.getQuals().removeObjCGCAttr();
4097   } else if (E->getBase()->isGLValue()) {
4098     // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
4099     // emit the base as an lvalue.
4100     assert(E->getBase()->getType()->isVectorType());
4101     Base = EmitLValue(E->getBase());
4102   } else {
4103     // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
4104     assert(E->getBase()->getType()->isVectorType() &&
4105            "Result must be a vector");
4106     llvm::Value *Vec = EmitScalarExpr(E->getBase());
4107 
4108     // Store the vector to memory (because LValue wants an address).
4109     Address VecMem = CreateMemTemp(E->getBase()->getType());
4110     Builder.CreateStore(Vec, VecMem);
4111     Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
4112                           AlignmentSource::Decl);
4113   }
4114 
4115   QualType type =
4116     E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
4117 
4118   // Encode the element access list into a vector of unsigned indices.
4119   SmallVector<uint32_t, 4> Indices;
4120   E->getEncodedElementAccess(Indices);
4121 
4122   if (Base.isSimple()) {
4123     llvm::Constant *CV =
4124         llvm::ConstantDataVector::get(getLLVMContext(), Indices);
4125     return LValue::MakeExtVectorElt(Base.getAddress(*this), CV, type,
4126                                     Base.getBaseInfo(), TBAAAccessInfo());
4127   }
4128   assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
4129 
4130   llvm::Constant *BaseElts = Base.getExtVectorElts();
4131   SmallVector<llvm::Constant *, 4> CElts;
4132 
4133   for (unsigned i = 0, e = Indices.size(); i != e; ++i)
4134     CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
4135   llvm::Constant *CV = llvm::ConstantVector::get(CElts);
4136   return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
4137                                   Base.getBaseInfo(), TBAAAccessInfo());
4138 }
4139 
4140 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
4141   if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
4142     EmitIgnoredExpr(E->getBase());
4143     return EmitDeclRefLValue(DRE);
4144   }
4145 
4146   Expr *BaseExpr = E->getBase();
4147   // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
4148   LValue BaseLV;
4149   if (E->isArrow()) {
4150     LValueBaseInfo BaseInfo;
4151     TBAAAccessInfo TBAAInfo;
4152     Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
4153     QualType PtrTy = BaseExpr->getType()->getPointeeType();
4154     SanitizerSet SkippedChecks;
4155     bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
4156     if (IsBaseCXXThis)
4157       SkippedChecks.set(SanitizerKind::Alignment, true);
4158     if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
4159       SkippedChecks.set(SanitizerKind::Null, true);
4160     EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
4161                   /*Alignment=*/CharUnits::Zero(), SkippedChecks);
4162     BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
4163   } else
4164     BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
4165 
4166   NamedDecl *ND = E->getMemberDecl();
4167   if (auto *Field = dyn_cast<FieldDecl>(ND)) {
4168     LValue LV = EmitLValueForField(BaseLV, Field);
4169     setObjCGCLValueClass(getContext(), E, LV);
4170     if (getLangOpts().OpenMP) {
4171       // If the member was explicitly marked as nontemporal, mark it as
4172       // nontemporal. If the base lvalue is marked as nontemporal, mark access
4173       // to children as nontemporal too.
4174       if ((IsWrappedCXXThis(BaseExpr) &&
4175            CGM.getOpenMPRuntime().isNontemporalDecl(Field)) ||
4176           BaseLV.isNontemporal())
4177         LV.setNontemporal(/*Value=*/true);
4178     }
4179     return LV;
4180   }
4181 
4182   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
4183     return EmitFunctionDeclLValue(*this, E, FD);
4184 
4185   llvm_unreachable("Unhandled member declaration!");
4186 }
4187 
4188 /// Given that we are currently emitting a lambda, emit an l-value for
4189 /// one of its members.
4190 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
4191   if (CurCodeDecl) {
4192     assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
4193     assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
4194   }
4195   QualType LambdaTagType =
4196     getContext().getTagDeclType(Field->getParent());
4197   LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
4198   return EmitLValueForField(LambdaLV, Field);
4199 }
4200 
4201 /// Get the field index in the debug info. The debug info structure/union
4202 /// will ignore the unnamed bitfields.
4203 unsigned CodeGenFunction::getDebugInfoFIndex(const RecordDecl *Rec,
4204                                              unsigned FieldIndex) {
4205   unsigned I = 0, Skipped = 0;
4206 
4207   for (auto F : Rec->getDefinition()->fields()) {
4208     if (I == FieldIndex)
4209       break;
4210     if (F->isUnnamedBitfield())
4211       Skipped++;
4212     I++;
4213   }
4214 
4215   return FieldIndex - Skipped;
4216 }
4217 
4218 /// Get the address of a zero-sized field within a record. The resulting
4219 /// address doesn't necessarily have the right type.
4220 static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base,
4221                                        const FieldDecl *Field) {
4222   CharUnits Offset = CGF.getContext().toCharUnitsFromBits(
4223       CGF.getContext().getFieldOffset(Field));
4224   if (Offset.isZero())
4225     return Base;
4226   Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty);
4227   return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
4228 }
4229 
4230 /// Drill down to the storage of a field without walking into
4231 /// reference types.
4232 ///
4233 /// The resulting address doesn't necessarily have the right type.
4234 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
4235                                       const FieldDecl *field) {
4236   if (field->isZeroSize(CGF.getContext()))
4237     return emitAddrOfZeroSizeField(CGF, base, field);
4238 
4239   const RecordDecl *rec = field->getParent();
4240 
4241   unsigned idx =
4242     CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4243 
4244   return CGF.Builder.CreateStructGEP(base, idx, field->getName());
4245 }
4246 
4247 static Address emitPreserveStructAccess(CodeGenFunction &CGF, LValue base,
4248                                         Address addr, const FieldDecl *field) {
4249   const RecordDecl *rec = field->getParent();
4250   llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(
4251       base.getType(), rec->getLocation());
4252 
4253   unsigned idx =
4254       CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4255 
4256   return CGF.Builder.CreatePreserveStructAccessIndex(
4257       addr, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
4258 }
4259 
4260 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
4261   const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
4262   if (!RD)
4263     return false;
4264 
4265   if (RD->isDynamicClass())
4266     return true;
4267 
4268   for (const auto &Base : RD->bases())
4269     if (hasAnyVptr(Base.getType(), Context))
4270       return true;
4271 
4272   for (const FieldDecl *Field : RD->fields())
4273     if (hasAnyVptr(Field->getType(), Context))
4274       return true;
4275 
4276   return false;
4277 }
4278 
4279 LValue CodeGenFunction::EmitLValueForField(LValue base,
4280                                            const FieldDecl *field) {
4281   LValueBaseInfo BaseInfo = base.getBaseInfo();
4282 
4283   if (field->isBitField()) {
4284     const CGRecordLayout &RL =
4285         CGM.getTypes().getCGRecordLayout(field->getParent());
4286     const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
4287     const bool UseVolatile = isAAPCS(CGM.getTarget()) &&
4288                              CGM.getCodeGenOpts().AAPCSBitfieldWidth &&
4289                              Info.VolatileStorageSize != 0 &&
4290                              field->getType()
4291                                  .withCVRQualifiers(base.getVRQualifiers())
4292                                  .isVolatileQualified();
4293     Address Addr = base.getAddress(*this);
4294     unsigned Idx = RL.getLLVMFieldNo(field);
4295     const RecordDecl *rec = field->getParent();
4296     if (!UseVolatile) {
4297       if (!IsInPreservedAIRegion &&
4298           (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4299         if (Idx != 0)
4300           // For structs, we GEP to the field that the record layout suggests.
4301           Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
4302       } else {
4303         llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4304             getContext().getRecordType(rec), rec->getLocation());
4305         Addr = Builder.CreatePreserveStructAccessIndex(
4306             Addr, Idx, getDebugInfoFIndex(rec, field->getFieldIndex()),
4307             DbgInfo);
4308       }
4309     }
4310     const unsigned SS =
4311         UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
4312     // Get the access type.
4313     llvm::Type *FieldIntTy = llvm::Type::getIntNTy(getLLVMContext(), SS);
4314     if (Addr.getElementType() != FieldIntTy)
4315       Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
4316     if (UseVolatile) {
4317       const unsigned VolatileOffset = Info.VolatileStorageOffset.getQuantity();
4318       if (VolatileOffset)
4319         Addr = Builder.CreateConstInBoundsGEP(Addr, VolatileOffset);
4320     }
4321 
4322     QualType fieldType =
4323         field->getType().withCVRQualifiers(base.getVRQualifiers());
4324     // TODO: Support TBAA for bit fields.
4325     LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4326     return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4327                                 TBAAAccessInfo());
4328   }
4329 
4330   // Fields of may-alias structures are may-alias themselves.
4331   // FIXME: this should get propagated down through anonymous structs
4332   // and unions.
4333   QualType FieldType = field->getType();
4334   const RecordDecl *rec = field->getParent();
4335   AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4336   LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4337   TBAAAccessInfo FieldTBAAInfo;
4338   if (base.getTBAAInfo().isMayAlias() ||
4339           rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4340     FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4341   } else if (rec->isUnion()) {
4342     // TODO: Support TBAA for unions.
4343     FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4344   } else {
4345     // If no base type been assigned for the base access, then try to generate
4346     // one for this base lvalue.
4347     FieldTBAAInfo = base.getTBAAInfo();
4348     if (!FieldTBAAInfo.BaseType) {
4349         FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4350         assert(!FieldTBAAInfo.Offset &&
4351                "Nonzero offset for an access with no base type!");
4352     }
4353 
4354     // Adjust offset to be relative to the base type.
4355     const ASTRecordLayout &Layout =
4356         getContext().getASTRecordLayout(field->getParent());
4357     unsigned CharWidth = getContext().getCharWidth();
4358     if (FieldTBAAInfo.BaseType)
4359       FieldTBAAInfo.Offset +=
4360           Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4361 
4362     // Update the final access type and size.
4363     FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4364     FieldTBAAInfo.Size =
4365         getContext().getTypeSizeInChars(FieldType).getQuantity();
4366   }
4367 
4368   Address addr = base.getAddress(*this);
4369   if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4370     if (CGM.getCodeGenOpts().StrictVTablePointers &&
4371         ClassDef->isDynamicClass()) {
4372       // Getting to any field of dynamic object requires stripping dynamic
4373       // information provided by invariant.group.  This is because accessing
4374       // fields may leak the real address of dynamic object, which could result
4375       // in miscompilation when leaked pointer would be compared.
4376       auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4377       addr = Address(stripped, addr.getAlignment());
4378     }
4379   }
4380 
4381   unsigned RecordCVR = base.getVRQualifiers();
4382   if (rec->isUnion()) {
4383     // For unions, there is no pointer adjustment.
4384     if (CGM.getCodeGenOpts().StrictVTablePointers &&
4385         hasAnyVptr(FieldType, getContext()))
4386       // Because unions can easily skip invariant.barriers, we need to add
4387       // a barrier every time CXXRecord field with vptr is referenced.
4388       addr = Builder.CreateLaunderInvariantGroup(addr);
4389 
4390     if (IsInPreservedAIRegion ||
4391         (getDebugInfo() && rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4392       // Remember the original union field index
4393       llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateStandaloneType(base.getType(),
4394           rec->getLocation());
4395       addr = Address(
4396           Builder.CreatePreserveUnionAccessIndex(
4397               addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4398           addr.getAlignment());
4399     }
4400 
4401     if (FieldType->isReferenceType())
4402       addr = Builder.CreateElementBitCast(
4403           addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4404   } else {
4405     if (!IsInPreservedAIRegion &&
4406         (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>()))
4407       // For structs, we GEP to the field that the record layout suggests.
4408       addr = emitAddrOfFieldStorage(*this, addr, field);
4409     else
4410       // Remember the original struct field index
4411       addr = emitPreserveStructAccess(*this, base, addr, field);
4412   }
4413 
4414   // If this is a reference field, load the reference right now.
4415   if (FieldType->isReferenceType()) {
4416     LValue RefLVal =
4417         MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4418     if (RecordCVR & Qualifiers::Volatile)
4419       RefLVal.getQuals().addVolatile();
4420     addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4421 
4422     // Qualifiers on the struct don't apply to the referencee.
4423     RecordCVR = 0;
4424     FieldType = FieldType->getPointeeType();
4425   }
4426 
4427   // Make sure that the address is pointing to the right type.  This is critical
4428   // for both unions and structs.  A union needs a bitcast, a struct element
4429   // will need a bitcast if the LLVM type laid out doesn't match the desired
4430   // type.
4431   addr = Builder.CreateElementBitCast(
4432       addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4433 
4434   if (field->hasAttr<AnnotateAttr>())
4435     addr = EmitFieldAnnotations(field, addr);
4436 
4437   LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4438   LV.getQuals().addCVRQualifiers(RecordCVR);
4439 
4440   // __weak attribute on a field is ignored.
4441   if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4442     LV.getQuals().removeObjCGCAttr();
4443 
4444   return LV;
4445 }
4446 
4447 LValue
4448 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
4449                                                   const FieldDecl *Field) {
4450   QualType FieldType = Field->getType();
4451 
4452   if (!FieldType->isReferenceType())
4453     return EmitLValueForField(Base, Field);
4454 
4455   Address V = emitAddrOfFieldStorage(*this, Base.getAddress(*this), Field);
4456 
4457   // Make sure that the address is pointing to the right type.
4458   llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4459   V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4460 
4461   // TODO: Generate TBAA information that describes this access as a structure
4462   // member access and not just an access to an object of the field's type. This
4463   // should be similar to what we do in EmitLValueForField().
4464   LValueBaseInfo BaseInfo = Base.getBaseInfo();
4465   AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4466   LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4467   return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4468                         CGM.getTBAAInfoForSubobject(Base, FieldType));
4469 }
4470 
4471 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
4472   if (E->isFileScope()) {
4473     ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
4474     return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4475   }
4476   if (E->getType()->isVariablyModifiedType())
4477     // make sure to emit the VLA size.
4478     EmitVariablyModifiedType(E->getType());
4479 
4480   Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4481   const Expr *InitExpr = E->getInitializer();
4482   LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4483 
4484   EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4485                    /*Init*/ true);
4486 
4487   // Block-scope compound literals are destroyed at the end of the enclosing
4488   // scope in C.
4489   if (!getLangOpts().CPlusPlus)
4490     if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
4491       pushLifetimeExtendedDestroy(getCleanupKind(DtorKind), DeclPtr,
4492                                   E->getType(), getDestroyer(DtorKind),
4493                                   DtorKind & EHCleanup);
4494 
4495   return Result;
4496 }
4497 
4498 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
4499   if (!E->isGLValue())
4500     // Initializing an aggregate temporary in C++11: T{...}.
4501     return EmitAggExprToLValue(E);
4502 
4503   // An lvalue initializer list must be initializing a reference.
4504   assert(E->isTransparent() && "non-transparent glvalue init list");
4505   return EmitLValue(E->getInit(0));
4506 }
4507 
4508 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4509 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4510 /// LValue is returned and the current block has been terminated.
4511 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
4512                                                     const Expr *Operand) {
4513   if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4514     CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4515     return None;
4516   }
4517 
4518   return CGF.EmitLValue(Operand);
4519 }
4520 
4521 LValue CodeGenFunction::
4522 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
4523   if (!expr->isGLValue()) {
4524     // ?: here should be an aggregate.
4525     assert(hasAggregateEvaluationKind(expr->getType()) &&
4526            "Unexpected conditional operator!");
4527     return EmitAggExprToLValue(expr);
4528   }
4529 
4530   OpaqueValueMapping binding(*this, expr);
4531 
4532   const Expr *condExpr = expr->getCond();
4533   bool CondExprBool;
4534   if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4535     const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4536     if (!CondExprBool) std::swap(live, dead);
4537 
4538     if (!ContainsLabel(dead)) {
4539       // If the true case is live, we need to track its region.
4540       if (CondExprBool)
4541         incrementProfileCounter(expr);
4542       // If a throw expression we emit it and return an undefined lvalue
4543       // because it can't be used.
4544       if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(live->IgnoreParens())) {
4545         EmitCXXThrowExpr(ThrowExpr);
4546         llvm::Type *ElemTy = ConvertType(dead->getType());
4547         llvm::Type *Ty = llvm::PointerType::getUnqual(ElemTy);
4548         return MakeAddrLValue(
4549             Address(llvm::UndefValue::get(Ty), ElemTy, CharUnits::One()),
4550             dead->getType());
4551       }
4552       return EmitLValue(live);
4553     }
4554   }
4555 
4556   llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4557   llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4558   llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4559 
4560   ConditionalEvaluation eval(*this);
4561   EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4562 
4563   // Any temporaries created here are conditional.
4564   EmitBlock(lhsBlock);
4565   incrementProfileCounter(expr);
4566   eval.begin(*this);
4567   Optional<LValue> lhs =
4568       EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4569   eval.end(*this);
4570 
4571   if (lhs && !lhs->isSimple())
4572     return EmitUnsupportedLValue(expr, "conditional operator");
4573 
4574   lhsBlock = Builder.GetInsertBlock();
4575   if (lhs)
4576     Builder.CreateBr(contBlock);
4577 
4578   // Any temporaries created here are conditional.
4579   EmitBlock(rhsBlock);
4580   eval.begin(*this);
4581   Optional<LValue> rhs =
4582       EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4583   eval.end(*this);
4584   if (rhs && !rhs->isSimple())
4585     return EmitUnsupportedLValue(expr, "conditional operator");
4586   rhsBlock = Builder.GetInsertBlock();
4587 
4588   EmitBlock(contBlock);
4589 
4590   if (lhs && rhs) {
4591     Address lhsAddr = lhs->getAddress(*this);
4592     Address rhsAddr = rhs->getAddress(*this);
4593     llvm::PHINode *phi = Builder.CreatePHI(lhsAddr.getType(), 2, "cond-lvalue");
4594     phi->addIncoming(lhsAddr.getPointer(), lhsBlock);
4595     phi->addIncoming(rhsAddr.getPointer(), rhsBlock);
4596     Address result(phi, lhsAddr.getElementType(),
4597                    std::min(lhsAddr.getAlignment(), rhsAddr.getAlignment()));
4598     AlignmentSource alignSource =
4599       std::max(lhs->getBaseInfo().getAlignmentSource(),
4600                rhs->getBaseInfo().getAlignmentSource());
4601     TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator(
4602         lhs->getTBAAInfo(), rhs->getTBAAInfo());
4603     return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4604                           TBAAInfo);
4605   } else {
4606     assert((lhs || rhs) &&
4607            "both operands of glvalue conditional are throw-expressions?");
4608     return lhs ? *lhs : *rhs;
4609   }
4610 }
4611 
4612 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4613 /// type. If the cast is to a reference, we can have the usual lvalue result,
4614 /// otherwise if a cast is needed by the code generator in an lvalue context,
4615 /// then it must mean that we need the address of an aggregate in order to
4616 /// access one of its members.  This can happen for all the reasons that casts
4617 /// are permitted with aggregate result, including noop aggregate casts, and
4618 /// cast from scalar to union.
4619 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
4620   switch (E->getCastKind()) {
4621   case CK_ToVoid:
4622   case CK_BitCast:
4623   case CK_LValueToRValueBitCast:
4624   case CK_ArrayToPointerDecay:
4625   case CK_FunctionToPointerDecay:
4626   case CK_NullToMemberPointer:
4627   case CK_NullToPointer:
4628   case CK_IntegralToPointer:
4629   case CK_PointerToIntegral:
4630   case CK_PointerToBoolean:
4631   case CK_VectorSplat:
4632   case CK_IntegralCast:
4633   case CK_BooleanToSignedIntegral:
4634   case CK_IntegralToBoolean:
4635   case CK_IntegralToFloating:
4636   case CK_FloatingToIntegral:
4637   case CK_FloatingToBoolean:
4638   case CK_FloatingCast:
4639   case CK_FloatingRealToComplex:
4640   case CK_FloatingComplexToReal:
4641   case CK_FloatingComplexToBoolean:
4642   case CK_FloatingComplexCast:
4643   case CK_FloatingComplexToIntegralComplex:
4644   case CK_IntegralRealToComplex:
4645   case CK_IntegralComplexToReal:
4646   case CK_IntegralComplexToBoolean:
4647   case CK_IntegralComplexCast:
4648   case CK_IntegralComplexToFloatingComplex:
4649   case CK_DerivedToBaseMemberPointer:
4650   case CK_BaseToDerivedMemberPointer:
4651   case CK_MemberPointerToBoolean:
4652   case CK_ReinterpretMemberPointer:
4653   case CK_AnyPointerToBlockPointerCast:
4654   case CK_ARCProduceObject:
4655   case CK_ARCConsumeObject:
4656   case CK_ARCReclaimReturnedObject:
4657   case CK_ARCExtendBlockObject:
4658   case CK_CopyAndAutoreleaseBlockObject:
4659   case CK_IntToOCLSampler:
4660   case CK_FloatingToFixedPoint:
4661   case CK_FixedPointToFloating:
4662   case CK_FixedPointCast:
4663   case CK_FixedPointToBoolean:
4664   case CK_FixedPointToIntegral:
4665   case CK_IntegralToFixedPoint:
4666   case CK_MatrixCast:
4667     return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4668 
4669   case CK_Dependent:
4670     llvm_unreachable("dependent cast kind in IR gen!");
4671 
4672   case CK_BuiltinFnToFnPtr:
4673     llvm_unreachable("builtin functions are handled elsewhere");
4674 
4675   // These are never l-values; just use the aggregate emission code.
4676   case CK_NonAtomicToAtomic:
4677   case CK_AtomicToNonAtomic:
4678     return EmitAggExprToLValue(E);
4679 
4680   case CK_Dynamic: {
4681     LValue LV = EmitLValue(E->getSubExpr());
4682     Address V = LV.getAddress(*this);
4683     const auto *DCE = cast<CXXDynamicCastExpr>(E);
4684     return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4685   }
4686 
4687   case CK_ConstructorConversion:
4688   case CK_UserDefinedConversion:
4689   case CK_CPointerToObjCPointerCast:
4690   case CK_BlockPointerToObjCPointerCast:
4691   case CK_LValueToRValue:
4692     return EmitLValue(E->getSubExpr());
4693 
4694   case CK_NoOp: {
4695     // CK_NoOp can model a qualification conversion, which can remove an array
4696     // bound and change the IR type.
4697     // FIXME: Once pointee types are removed from IR, remove this.
4698     LValue LV = EmitLValue(E->getSubExpr());
4699     if (LV.isSimple()) {
4700       Address V = LV.getAddress(*this);
4701       if (V.isValid()) {
4702         llvm::Type *T = ConvertTypeForMem(E->getType());
4703         if (V.getElementType() != T)
4704           LV.setAddress(Builder.CreateElementBitCast(V, T));
4705       }
4706     }
4707     return LV;
4708   }
4709 
4710   case CK_UncheckedDerivedToBase:
4711   case CK_DerivedToBase: {
4712     const auto *DerivedClassTy =
4713         E->getSubExpr()->getType()->castAs<RecordType>();
4714     auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4715 
4716     LValue LV = EmitLValue(E->getSubExpr());
4717     Address This = LV.getAddress(*this);
4718 
4719     // Perform the derived-to-base conversion
4720     Address Base = GetAddressOfBaseClass(
4721         This, DerivedClassDecl, E->path_begin(), E->path_end(),
4722         /*NullCheckValue=*/false, E->getExprLoc());
4723 
4724     // TODO: Support accesses to members of base classes in TBAA. For now, we
4725     // conservatively pretend that the complete object is of the base class
4726     // type.
4727     return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4728                           CGM.getTBAAInfoForSubobject(LV, E->getType()));
4729   }
4730   case CK_ToUnion:
4731     return EmitAggExprToLValue(E);
4732   case CK_BaseToDerived: {
4733     const auto *DerivedClassTy = E->getType()->castAs<RecordType>();
4734     auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4735 
4736     LValue LV = EmitLValue(E->getSubExpr());
4737 
4738     // Perform the base-to-derived conversion
4739     Address Derived = GetAddressOfDerivedClass(
4740         LV.getAddress(*this), DerivedClassDecl, E->path_begin(), E->path_end(),
4741         /*NullCheckValue=*/false);
4742 
4743     // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4744     // performed and the object is not of the derived type.
4745     if (sanitizePerformTypeCheck())
4746       EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
4747                     Derived.getPointer(), E->getType());
4748 
4749     if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4750       EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4751                                 /*MayBeNull=*/false, CFITCK_DerivedCast,
4752                                 E->getBeginLoc());
4753 
4754     return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4755                           CGM.getTBAAInfoForSubobject(LV, E->getType()));
4756   }
4757   case CK_LValueBitCast: {
4758     // This must be a reinterpret_cast (or c-style equivalent).
4759     const auto *CE = cast<ExplicitCastExpr>(E);
4760 
4761     CGM.EmitExplicitCastExprType(CE, this);
4762     LValue LV = EmitLValue(E->getSubExpr());
4763     Address V = Builder.CreateElementBitCast(
4764         LV.getAddress(*this),
4765         ConvertTypeForMem(CE->getTypeAsWritten()->getPointeeType()));
4766 
4767     if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4768       EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4769                                 /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4770                                 E->getBeginLoc());
4771 
4772     return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4773                           CGM.getTBAAInfoForSubobject(LV, E->getType()));
4774   }
4775   case CK_AddressSpaceConversion: {
4776     LValue LV = EmitLValue(E->getSubExpr());
4777     QualType DestTy = getContext().getPointerType(E->getType());
4778     llvm::Value *V = getTargetHooks().performAddrSpaceCast(
4779         *this, LV.getPointer(*this),
4780         E->getSubExpr()->getType().getAddressSpace(),
4781         E->getType().getAddressSpace(), ConvertType(DestTy));
4782     return MakeAddrLValue(Address(V, LV.getAddress(*this).getAlignment()),
4783                           E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4784   }
4785   case CK_ObjCObjectLValueCast: {
4786     LValue LV = EmitLValue(E->getSubExpr());
4787     Address V = Builder.CreateElementBitCast(LV.getAddress(*this),
4788                                              ConvertType(E->getType()));
4789     return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4790                           CGM.getTBAAInfoForSubobject(LV, E->getType()));
4791   }
4792   case CK_ZeroToOCLOpaqueType:
4793     llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4794   }
4795 
4796   llvm_unreachable("Unhandled lvalue cast kind?");
4797 }
4798 
4799 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
4800   assert(OpaqueValueMappingData::shouldBindAsLValue(e));
4801   return getOrCreateOpaqueLValueMapping(e);
4802 }
4803 
4804 LValue
4805 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) {
4806   assert(OpaqueValueMapping::shouldBindAsLValue(e));
4807 
4808   llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4809       it = OpaqueLValues.find(e);
4810 
4811   if (it != OpaqueLValues.end())
4812     return it->second;
4813 
4814   assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4815   return EmitLValue(e->getSourceExpr());
4816 }
4817 
4818 RValue
4819 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) {
4820   assert(!OpaqueValueMapping::shouldBindAsLValue(e));
4821 
4822   llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4823       it = OpaqueRValues.find(e);
4824 
4825   if (it != OpaqueRValues.end())
4826     return it->second;
4827 
4828   assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4829   return EmitAnyExpr(e->getSourceExpr());
4830 }
4831 
4832 RValue CodeGenFunction::EmitRValueForField(LValue LV,
4833                                            const FieldDecl *FD,
4834                                            SourceLocation Loc) {
4835   QualType FT = FD->getType();
4836   LValue FieldLV = EmitLValueForField(LV, FD);
4837   switch (getEvaluationKind(FT)) {
4838   case TEK_Complex:
4839     return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4840   case TEK_Aggregate:
4841     return FieldLV.asAggregateRValue(*this);
4842   case TEK_Scalar:
4843     // This routine is used to load fields one-by-one to perform a copy, so
4844     // don't load reference fields.
4845     if (FD->getType()->isReferenceType())
4846       return RValue::get(FieldLV.getPointer(*this));
4847     // Call EmitLoadOfScalar except when the lvalue is a bitfield to emit a
4848     // primitive load.
4849     if (FieldLV.isBitField())
4850       return EmitLoadOfLValue(FieldLV, Loc);
4851     return RValue::get(EmitLoadOfScalar(FieldLV, Loc));
4852   }
4853   llvm_unreachable("bad evaluation kind");
4854 }
4855 
4856 //===--------------------------------------------------------------------===//
4857 //                             Expression Emission
4858 //===--------------------------------------------------------------------===//
4859 
4860 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
4861                                      ReturnValueSlot ReturnValue) {
4862   // Builtins never have block type.
4863   if (E->getCallee()->getType()->isBlockPointerType())
4864     return EmitBlockCallExpr(E, ReturnValue);
4865 
4866   if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4867     return EmitCXXMemberCallExpr(CE, ReturnValue);
4868 
4869   if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4870     return EmitCUDAKernelCallExpr(CE, ReturnValue);
4871 
4872   if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4873     if (const CXXMethodDecl *MD =
4874           dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4875       return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4876 
4877   CGCallee callee = EmitCallee(E->getCallee());
4878 
4879   if (callee.isBuiltin()) {
4880     return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4881                            E, ReturnValue);
4882   }
4883 
4884   if (callee.isPseudoDestructor()) {
4885     return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
4886   }
4887 
4888   return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4889 }
4890 
4891 /// Emit a CallExpr without considering whether it might be a subclass.
4892 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
4893                                            ReturnValueSlot ReturnValue) {
4894   CGCallee Callee = EmitCallee(E->getCallee());
4895   return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4896 }
4897 
4898 // Detect the unusual situation where an inline version is shadowed by a
4899 // non-inline version. In that case we should pick the external one
4900 // everywhere. That's GCC behavior too.
4901 static bool OnlyHasInlineBuiltinDeclaration(const FunctionDecl *FD) {
4902   for (const FunctionDecl *PD = FD; PD; PD = PD->getPreviousDecl())
4903     if (!PD->isInlineBuiltinDeclaration())
4904       return false;
4905   return true;
4906 }
4907 
4908 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, GlobalDecl GD) {
4909   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
4910 
4911   if (auto builtinID = FD->getBuiltinID()) {
4912     std::string FDInlineName = (FD->getName() + ".inline").str();
4913     // When directing calling an inline builtin, call it through it's mangled
4914     // name to make it clear it's not the actual builtin.
4915     if (CGF.CurFn->getName() != FDInlineName &&
4916         OnlyHasInlineBuiltinDeclaration(FD)) {
4917       llvm::Constant *CalleePtr = EmitFunctionDeclPointer(CGF.CGM, GD);
4918       llvm::Function *Fn = llvm::cast<llvm::Function>(CalleePtr);
4919       llvm::Module *M = Fn->getParent();
4920       llvm::Function *Clone = M->getFunction(FDInlineName);
4921       if (!Clone) {
4922         Clone = llvm::Function::Create(Fn->getFunctionType(),
4923                                        llvm::GlobalValue::InternalLinkage,
4924                                        Fn->getAddressSpace(), FDInlineName, M);
4925         Clone->addFnAttr(llvm::Attribute::AlwaysInline);
4926       }
4927       return CGCallee::forDirect(Clone, GD);
4928     }
4929 
4930     // Replaceable builtins provide their own implementation of a builtin. If we
4931     // are in an inline builtin implementation, avoid trivial infinite
4932     // recursion.
4933     else
4934       return CGCallee::forBuiltin(builtinID, FD);
4935   }
4936 
4937   llvm::Constant *CalleePtr = EmitFunctionDeclPointer(CGF.CGM, GD);
4938   if (CGF.CGM.getLangOpts().CUDA && !CGF.CGM.getLangOpts().CUDAIsDevice &&
4939       FD->hasAttr<CUDAGlobalAttr>())
4940     CalleePtr = CGF.CGM.getCUDARuntime().getKernelStub(
4941         cast<llvm::GlobalValue>(CalleePtr->stripPointerCasts()));
4942 
4943   return CGCallee::forDirect(CalleePtr, GD);
4944 }
4945 
4946 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
4947   E = E->IgnoreParens();
4948 
4949   // Look through function-to-pointer decay.
4950   if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4951     if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4952         ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4953       return EmitCallee(ICE->getSubExpr());
4954     }
4955 
4956   // Resolve direct calls.
4957   } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4958     if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4959       return EmitDirectCallee(*this, FD);
4960     }
4961   } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4962     if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4963       EmitIgnoredExpr(ME->getBase());
4964       return EmitDirectCallee(*this, FD);
4965     }
4966 
4967   // Look through template substitutions.
4968   } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4969     return EmitCallee(NTTP->getReplacement());
4970 
4971   // Treat pseudo-destructor calls differently.
4972   } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4973     return CGCallee::forPseudoDestructor(PDE);
4974   }
4975 
4976   // Otherwise, we have an indirect reference.
4977   llvm::Value *calleePtr;
4978   QualType functionType;
4979   if (auto ptrType = E->getType()->getAs<PointerType>()) {
4980     calleePtr = EmitScalarExpr(E);
4981     functionType = ptrType->getPointeeType();
4982   } else {
4983     functionType = E->getType();
4984     calleePtr = EmitLValue(E).getPointer(*this);
4985   }
4986   assert(functionType->isFunctionType());
4987 
4988   GlobalDecl GD;
4989   if (const auto *VD =
4990           dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4991     GD = GlobalDecl(VD);
4992 
4993   CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4994   CGCallee callee(calleeInfo, calleePtr);
4995   return callee;
4996 }
4997 
4998 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4999   // Comma expressions just emit their LHS then their RHS as an l-value.
5000   if (E->getOpcode() == BO_Comma) {
5001     EmitIgnoredExpr(E->getLHS());
5002     EnsureInsertPoint();
5003     return EmitLValue(E->getRHS());
5004   }
5005 
5006   if (E->getOpcode() == BO_PtrMemD ||
5007       E->getOpcode() == BO_PtrMemI)
5008     return EmitPointerToDataMemberBinaryExpr(E);
5009 
5010   assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
5011 
5012   // Note that in all of these cases, __block variables need the RHS
5013   // evaluated first just in case the variable gets moved by the RHS.
5014 
5015   switch (getEvaluationKind(E->getType())) {
5016   case TEK_Scalar: {
5017     switch (E->getLHS()->getType().getObjCLifetime()) {
5018     case Qualifiers::OCL_Strong:
5019       return EmitARCStoreStrong(E, /*ignored*/ false).first;
5020 
5021     case Qualifiers::OCL_Autoreleasing:
5022       return EmitARCStoreAutoreleasing(E).first;
5023 
5024     // No reason to do any of these differently.
5025     case Qualifiers::OCL_None:
5026     case Qualifiers::OCL_ExplicitNone:
5027     case Qualifiers::OCL_Weak:
5028       break;
5029     }
5030 
5031     RValue RV = EmitAnyExpr(E->getRHS());
5032     LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
5033     if (RV.isScalar())
5034       EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
5035     EmitStoreThroughLValue(RV, LV);
5036     if (getLangOpts().OpenMP)
5037       CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
5038                                                                 E->getLHS());
5039     return LV;
5040   }
5041 
5042   case TEK_Complex:
5043     return EmitComplexAssignmentLValue(E);
5044 
5045   case TEK_Aggregate:
5046     return EmitAggExprToLValue(E);
5047   }
5048   llvm_unreachable("bad evaluation kind");
5049 }
5050 
5051 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
5052   RValue RV = EmitCallExpr(E);
5053 
5054   if (!RV.isScalar())
5055     return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
5056                           AlignmentSource::Decl);
5057 
5058   assert(E->getCallReturnType(getContext())->isReferenceType() &&
5059          "Can't have a scalar return unless the return type is a "
5060          "reference type!");
5061 
5062   return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
5063 }
5064 
5065 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
5066   // FIXME: This shouldn't require another copy.
5067   return EmitAggExprToLValue(E);
5068 }
5069 
5070 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
5071   assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
5072          && "binding l-value to type which needs a temporary");
5073   AggValueSlot Slot = CreateAggTemp(E->getType());
5074   EmitCXXConstructExpr(E, Slot);
5075   return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
5076 }
5077 
5078 LValue
5079 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
5080   return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
5081 }
5082 
5083 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
5084   return Builder.CreateElementBitCast(CGM.GetAddrOfMSGuidDecl(E->getGuidDecl()),
5085                                       ConvertType(E->getType()));
5086 }
5087 
5088 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
5089   return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
5090                         AlignmentSource::Decl);
5091 }
5092 
5093 LValue
5094 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
5095   AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
5096   Slot.setExternallyDestructed();
5097   EmitAggExpr(E->getSubExpr(), Slot);
5098   EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
5099   return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
5100 }
5101 
5102 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
5103   RValue RV = EmitObjCMessageExpr(E);
5104 
5105   if (!RV.isScalar())
5106     return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
5107                           AlignmentSource::Decl);
5108 
5109   assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
5110          "Can't have a scalar return unless the return type is a "
5111          "reference type!");
5112 
5113   return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
5114 }
5115 
5116 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
5117   Address V =
5118     CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
5119   return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
5120 }
5121 
5122 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
5123                                              const ObjCIvarDecl *Ivar) {
5124   return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
5125 }
5126 
5127 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
5128                                           llvm::Value *BaseValue,
5129                                           const ObjCIvarDecl *Ivar,
5130                                           unsigned CVRQualifiers) {
5131   return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
5132                                                    Ivar, CVRQualifiers);
5133 }
5134 
5135 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
5136   // FIXME: A lot of the code below could be shared with EmitMemberExpr.
5137   llvm::Value *BaseValue = nullptr;
5138   const Expr *BaseExpr = E->getBase();
5139   Qualifiers BaseQuals;
5140   QualType ObjectTy;
5141   if (E->isArrow()) {
5142     BaseValue = EmitScalarExpr(BaseExpr);
5143     ObjectTy = BaseExpr->getType()->getPointeeType();
5144     BaseQuals = ObjectTy.getQualifiers();
5145   } else {
5146     LValue BaseLV = EmitLValue(BaseExpr);
5147     BaseValue = BaseLV.getPointer(*this);
5148     ObjectTy = BaseExpr->getType();
5149     BaseQuals = ObjectTy.getQualifiers();
5150   }
5151 
5152   LValue LV =
5153     EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
5154                       BaseQuals.getCVRQualifiers());
5155   setObjCGCLValueClass(getContext(), E, LV);
5156   return LV;
5157 }
5158 
5159 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
5160   // Can only get l-value for message expression returning aggregate type
5161   RValue RV = EmitAnyExprToTemp(E);
5162   return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
5163                         AlignmentSource::Decl);
5164 }
5165 
5166 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
5167                                  const CallExpr *E, ReturnValueSlot ReturnValue,
5168                                  llvm::Value *Chain) {
5169   // Get the actual function type. The callee type will always be a pointer to
5170   // function type or a block pointer type.
5171   assert(CalleeType->isFunctionPointerType() &&
5172          "Call must have function pointer type!");
5173 
5174   const Decl *TargetDecl =
5175       OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
5176 
5177   CalleeType = getContext().getCanonicalType(CalleeType);
5178 
5179   auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
5180 
5181   CGCallee Callee = OrigCallee;
5182 
5183   if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
5184       (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
5185     if (llvm::Constant *PrefixSig =
5186             CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
5187       SanitizerScope SanScope(this);
5188       // Remove any (C++17) exception specifications, to allow calling e.g. a
5189       // noexcept function through a non-noexcept pointer.
5190       auto ProtoTy =
5191         getContext().getFunctionTypeWithExceptionSpec(PointeeType, EST_None);
5192       llvm::Constant *FTRTTIConst =
5193           CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
5194       llvm::Type *PrefixSigType = PrefixSig->getType();
5195       llvm::StructType *PrefixStructTy = llvm::StructType::get(
5196           CGM.getLLVMContext(), {PrefixSigType, Int32Ty}, /*isPacked=*/true);
5197 
5198       llvm::Value *CalleePtr = Callee.getFunctionPointer();
5199 
5200       llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
5201           CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
5202       llvm::Value *CalleeSigPtr =
5203           Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
5204       llvm::Value *CalleeSig =
5205           Builder.CreateAlignedLoad(PrefixSigType, CalleeSigPtr, getIntAlign());
5206       llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
5207 
5208       llvm::BasicBlock *Cont = createBasicBlock("cont");
5209       llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
5210       Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
5211 
5212       EmitBlock(TypeCheck);
5213       llvm::Value *CalleeRTTIPtr =
5214           Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
5215       llvm::Value *CalleeRTTIEncoded =
5216           Builder.CreateAlignedLoad(Int32Ty, CalleeRTTIPtr, getPointerAlign());
5217       llvm::Value *CalleeRTTI =
5218           DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
5219       llvm::Value *CalleeRTTIMatch =
5220           Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
5221       llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()),
5222                                       EmitCheckTypeDescriptor(CalleeType)};
5223       EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
5224                 SanitizerHandler::FunctionTypeMismatch, StaticData,
5225                 {CalleePtr, CalleeRTTI, FTRTTIConst});
5226 
5227       Builder.CreateBr(Cont);
5228       EmitBlock(Cont);
5229     }
5230   }
5231 
5232   const auto *FnType = cast<FunctionType>(PointeeType);
5233 
5234   // If we are checking indirect calls and this call is indirect, check that the
5235   // function pointer is a member of the bit set for the function type.
5236   if (SanOpts.has(SanitizerKind::CFIICall) &&
5237       (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
5238     SanitizerScope SanScope(this);
5239     EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
5240 
5241     llvm::Metadata *MD;
5242     if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
5243       MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
5244     else
5245       MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
5246 
5247     llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
5248 
5249     llvm::Value *CalleePtr = Callee.getFunctionPointer();
5250     llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
5251     llvm::Value *TypeTest = Builder.CreateCall(
5252         CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
5253 
5254     auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
5255     llvm::Constant *StaticData[] = {
5256         llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
5257         EmitCheckSourceLocation(E->getBeginLoc()),
5258         EmitCheckTypeDescriptor(QualType(FnType, 0)),
5259     };
5260     if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
5261       EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
5262                            CastedCallee, StaticData);
5263     } else {
5264       EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
5265                 SanitizerHandler::CFICheckFail, StaticData,
5266                 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
5267     }
5268   }
5269 
5270   CallArgList Args;
5271   if (Chain)
5272     Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
5273              CGM.getContext().VoidPtrTy);
5274 
5275   // C++17 requires that we evaluate arguments to a call using assignment syntax
5276   // right-to-left, and that we evaluate arguments to certain other operators
5277   // left-to-right. Note that we allow this to override the order dictated by
5278   // the calling convention on the MS ABI, which means that parameter
5279   // destruction order is not necessarily reverse construction order.
5280   // FIXME: Revisit this based on C++ committee response to unimplementability.
5281   EvaluationOrder Order = EvaluationOrder::Default;
5282   if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
5283     if (OCE->isAssignmentOp())
5284       Order = EvaluationOrder::ForceRightToLeft;
5285     else {
5286       switch (OCE->getOperator()) {
5287       case OO_LessLess:
5288       case OO_GreaterGreater:
5289       case OO_AmpAmp:
5290       case OO_PipePipe:
5291       case OO_Comma:
5292       case OO_ArrowStar:
5293         Order = EvaluationOrder::ForceLeftToRight;
5294         break;
5295       default:
5296         break;
5297       }
5298     }
5299   }
5300 
5301   EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
5302                E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
5303 
5304   const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
5305       Args, FnType, /*ChainCall=*/Chain);
5306 
5307   // C99 6.5.2.2p6:
5308   //   If the expression that denotes the called function has a type
5309   //   that does not include a prototype, [the default argument
5310   //   promotions are performed]. If the number of arguments does not
5311   //   equal the number of parameters, the behavior is undefined. If
5312   //   the function is defined with a type that includes a prototype,
5313   //   and either the prototype ends with an ellipsis (, ...) or the
5314   //   types of the arguments after promotion are not compatible with
5315   //   the types of the parameters, the behavior is undefined. If the
5316   //   function is defined with a type that does not include a
5317   //   prototype, and the types of the arguments after promotion are
5318   //   not compatible with those of the parameters after promotion,
5319   //   the behavior is undefined [except in some trivial cases].
5320   // That is, in the general case, we should assume that a call
5321   // through an unprototyped function type works like a *non-variadic*
5322   // call.  The way we make this work is to cast to the exact type
5323   // of the promoted arguments.
5324   //
5325   // Chain calls use this same code path to add the invisible chain parameter
5326   // to the function type.
5327   if (isa<FunctionNoProtoType>(FnType) || Chain) {
5328     llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
5329     int AS = Callee.getFunctionPointer()->getType()->getPointerAddressSpace();
5330     CalleeTy = CalleeTy->getPointerTo(AS);
5331 
5332     llvm::Value *CalleePtr = Callee.getFunctionPointer();
5333     CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
5334     Callee.setFunctionPointer(CalleePtr);
5335   }
5336 
5337   // HIP function pointer contains kernel handle when it is used in triple
5338   // chevron. The kernel stub needs to be loaded from kernel handle and used
5339   // as callee.
5340   if (CGM.getLangOpts().HIP && !CGM.getLangOpts().CUDAIsDevice &&
5341       isa<CUDAKernelCallExpr>(E) &&
5342       (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
5343     llvm::Value *Handle = Callee.getFunctionPointer();
5344     auto *Cast =
5345         Builder.CreateBitCast(Handle, Handle->getType()->getPointerTo());
5346     auto *Stub = Builder.CreateLoad(Address(Cast, CGM.getPointerAlign()));
5347     Callee.setFunctionPointer(Stub);
5348   }
5349   llvm::CallBase *CallOrInvoke = nullptr;
5350   RValue Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &CallOrInvoke,
5351                          E == MustTailCall, E->getExprLoc());
5352 
5353   // Generate function declaration DISuprogram in order to be used
5354   // in debug info about call sites.
5355   if (CGDebugInfo *DI = getDebugInfo()) {
5356     if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
5357       FunctionArgList Args;
5358       QualType ResTy = BuildFunctionArgList(CalleeDecl, Args);
5359       DI->EmitFuncDeclForCallSite(CallOrInvoke,
5360                                   DI->getFunctionType(CalleeDecl, ResTy, Args),
5361                                   CalleeDecl);
5362     }
5363   }
5364 
5365   return Call;
5366 }
5367 
5368 LValue CodeGenFunction::
5369 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
5370   Address BaseAddr = Address::invalid();
5371   if (E->getOpcode() == BO_PtrMemI) {
5372     BaseAddr = EmitPointerWithAlignment(E->getLHS());
5373   } else {
5374     BaseAddr = EmitLValue(E->getLHS()).getAddress(*this);
5375   }
5376 
5377   llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
5378   const auto *MPT = E->getRHS()->getType()->castAs<MemberPointerType>();
5379 
5380   LValueBaseInfo BaseInfo;
5381   TBAAAccessInfo TBAAInfo;
5382   Address MemberAddr =
5383     EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
5384                                     &TBAAInfo);
5385 
5386   return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
5387 }
5388 
5389 /// Given the address of a temporary variable, produce an r-value of
5390 /// its type.
5391 RValue CodeGenFunction::convertTempToRValue(Address addr,
5392                                             QualType type,
5393                                             SourceLocation loc) {
5394   LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
5395   switch (getEvaluationKind(type)) {
5396   case TEK_Complex:
5397     return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
5398   case TEK_Aggregate:
5399     return lvalue.asAggregateRValue(*this);
5400   case TEK_Scalar:
5401     return RValue::get(EmitLoadOfScalar(lvalue, loc));
5402   }
5403   llvm_unreachable("bad evaluation kind");
5404 }
5405 
5406 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
5407   assert(Val->getType()->isFPOrFPVectorTy());
5408   if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
5409     return;
5410 
5411   llvm::MDBuilder MDHelper(getLLVMContext());
5412   llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
5413 
5414   cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
5415 }
5416 
5417 namespace {
5418   struct LValueOrRValue {
5419     LValue LV;
5420     RValue RV;
5421   };
5422 }
5423 
5424 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
5425                                            const PseudoObjectExpr *E,
5426                                            bool forLValue,
5427                                            AggValueSlot slot) {
5428   SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
5429 
5430   // Find the result expression, if any.
5431   const Expr *resultExpr = E->getResultExpr();
5432   LValueOrRValue result;
5433 
5434   for (PseudoObjectExpr::const_semantics_iterator
5435          i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
5436     const Expr *semantic = *i;
5437 
5438     // If this semantic expression is an opaque value, bind it
5439     // to the result of its source expression.
5440     if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
5441       // Skip unique OVEs.
5442       if (ov->isUnique()) {
5443         assert(ov != resultExpr &&
5444                "A unique OVE cannot be used as the result expression");
5445         continue;
5446       }
5447 
5448       // If this is the result expression, we may need to evaluate
5449       // directly into the slot.
5450       typedef CodeGenFunction::OpaqueValueMappingData OVMA;
5451       OVMA opaqueData;
5452       if (ov == resultExpr && ov->isPRValue() && !forLValue &&
5453           CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
5454         CGF.EmitAggExpr(ov->getSourceExpr(), slot);
5455         LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
5456                                        AlignmentSource::Decl);
5457         opaqueData = OVMA::bind(CGF, ov, LV);
5458         result.RV = slot.asRValue();
5459 
5460       // Otherwise, emit as normal.
5461       } else {
5462         opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
5463 
5464         // If this is the result, also evaluate the result now.
5465         if (ov == resultExpr) {
5466           if (forLValue)
5467             result.LV = CGF.EmitLValue(ov);
5468           else
5469             result.RV = CGF.EmitAnyExpr(ov, slot);
5470         }
5471       }
5472 
5473       opaques.push_back(opaqueData);
5474 
5475     // Otherwise, if the expression is the result, evaluate it
5476     // and remember the result.
5477     } else if (semantic == resultExpr) {
5478       if (forLValue)
5479         result.LV = CGF.EmitLValue(semantic);
5480       else
5481         result.RV = CGF.EmitAnyExpr(semantic, slot);
5482 
5483     // Otherwise, evaluate the expression in an ignored context.
5484     } else {
5485       CGF.EmitIgnoredExpr(semantic);
5486     }
5487   }
5488 
5489   // Unbind all the opaques now.
5490   for (unsigned i = 0, e = opaques.size(); i != e; ++i)
5491     opaques[i].unbind(CGF);
5492 
5493   return result;
5494 }
5495 
5496 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
5497                                                AggValueSlot slot) {
5498   return emitPseudoObjectExpr(*this, E, false, slot).RV;
5499 }
5500 
5501 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
5502   return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;
5503 }
5504