CGExpr.cpp revision e4330726b8070bb7094414507a1040972ee52474 
1//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CodeGenModule.h"
16#include "CGCall.h"
17#include "CGCXXABI.h"
18#include "CGDebugInfo.h"
19#include "CGRecordLayout.h"
20#include "CGObjCRuntime.h"
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/Frontend/CodeGenOptions.h"
24#include "llvm/Intrinsics.h"
25#include "llvm/Target/TargetData.h"
26using namespace clang;
27using namespace CodeGen;
28
29//===--------------------------------------------------------------------===//
30//                        Miscellaneous Helper Methods
31//===--------------------------------------------------------------------===//
32
33llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
34  unsigned addressSpace =
35    cast<llvm::PointerType>(value->getType())->getAddressSpace();
36
37  const llvm::PointerType *destType = Int8PtrTy;
38  if (addressSpace)
39    destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
40
41  if (value->getType() == destType) return value;
42  return Builder.CreateBitCast(value, destType);
43}
44
45/// CreateTempAlloca - This creates a alloca and inserts it into the entry
46/// block.
47llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
48                                                    const llvm::Twine &Name) {
49  if (!Builder.isNamePreserving())
50    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
51  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
52}
53
54void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
55                                     llvm::Value *Init) {
56  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
57  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
58  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
59}
60
61llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
62                                                const llvm::Twine &Name) {
63  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
64  // FIXME: Should we prefer the preferred type alignment here?
65  CharUnits Align = getContext().getTypeAlignInChars(Ty);
66  Alloc->setAlignment(Align.getQuantity());
67  return Alloc;
68}
69
70llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
71                                                 const llvm::Twine &Name) {
72  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
73  // FIXME: Should we prefer the preferred type alignment here?
74  CharUnits Align = getContext().getTypeAlignInChars(Ty);
75  Alloc->setAlignment(Align.getQuantity());
76  return Alloc;
77}
78
79/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
80/// expression and compare the result against zero, returning an Int1Ty value.
81llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
82  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
83    llvm::Value *MemPtr = EmitScalarExpr(E);
84    return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
85  }
86
87  QualType BoolTy = getContext().BoolTy;
88  if (!E->getType()->isAnyComplexType())
89    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
90
91  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
92}
93
94/// EmitIgnoredExpr - Emit code to compute the specified expression,
95/// ignoring the result.
96void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
97  if (E->isRValue())
98    return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
99
100  // Just emit it as an l-value and drop the result.
101  EmitLValue(E);
102}
103
104/// EmitAnyExpr - Emit code to compute the specified expression which
105/// can have any type.  The result is returned as an RValue struct.
106/// If this is an aggregate expression, AggSlot indicates where the
107/// result should be returned.
108RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot,
109                                    bool IgnoreResult) {
110  if (!hasAggregateLLVMType(E->getType()))
111    return RValue::get(EmitScalarExpr(E, IgnoreResult));
112  else if (E->getType()->isAnyComplexType())
113    return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult));
114
115  EmitAggExpr(E, AggSlot, IgnoreResult);
116  return AggSlot.asRValue();
117}
118
119/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
120/// always be accessible even if no aggregate location is provided.
121RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
122  AggValueSlot AggSlot = AggValueSlot::ignored();
123
124  if (hasAggregateLLVMType(E->getType()) &&
125      !E->getType()->isAnyComplexType())
126    AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
127  return EmitAnyExpr(E, AggSlot);
128}
129
130/// EmitAnyExprToMem - Evaluate an expression into a given memory
131/// location.
132void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
133                                       llvm::Value *Location,
134                                       Qualifiers Quals,
135                                       bool IsInit) {
136  if (E->getType()->isAnyComplexType())
137    EmitComplexExprIntoAddr(E, Location, Quals.hasVolatile());
138  else if (hasAggregateLLVMType(E->getType()))
139    EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals, IsInit));
140  else {
141    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
142    LValue LV = MakeAddrLValue(Location, E->getType());
143    EmitStoreThroughLValue(RV, LV);
144  }
145}
146
147namespace {
148/// \brief An adjustment to be made to the temporary created when emitting a
149/// reference binding, which accesses a particular subobject of that temporary.
150  struct SubobjectAdjustment {
151    enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
152
153    union {
154      struct {
155        const CastExpr *BasePath;
156        const CXXRecordDecl *DerivedClass;
157      } DerivedToBase;
158
159      FieldDecl *Field;
160    };
161
162    SubobjectAdjustment(const CastExpr *BasePath,
163                        const CXXRecordDecl *DerivedClass)
164      : Kind(DerivedToBaseAdjustment) {
165      DerivedToBase.BasePath = BasePath;
166      DerivedToBase.DerivedClass = DerivedClass;
167    }
168
169    SubobjectAdjustment(FieldDecl *Field)
170      : Kind(FieldAdjustment) {
171      this->Field = Field;
172    }
173  };
174}
175
176static llvm::Value *
177CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
178                         const NamedDecl *InitializedDecl) {
179  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
180    if (VD->hasGlobalStorage()) {
181      llvm::SmallString<256> Name;
182      llvm::raw_svector_ostream Out(Name);
183      CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out);
184      Out.flush();
185
186      const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
187
188      // Create the reference temporary.
189      llvm::GlobalValue *RefTemp =
190        new llvm::GlobalVariable(CGF.CGM.getModule(),
191                                 RefTempTy, /*isConstant=*/false,
192                                 llvm::GlobalValue::InternalLinkage,
193                                 llvm::Constant::getNullValue(RefTempTy),
194                                 Name.str());
195      return RefTemp;
196    }
197  }
198
199  return CGF.CreateMemTemp(Type, "ref.tmp");
200}
201
202static llvm::Value *
203EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
204                            llvm::Value *&ReferenceTemporary,
205                            const CXXDestructorDecl *&ReferenceTemporaryDtor,
206                            QualType &ObjCARCReferenceLifetimeType,
207                            const NamedDecl *InitializedDecl) {
208  // Look through expressions for materialized temporaries (for now).
209  if (const MaterializeTemporaryExpr *M
210                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
211    // Objective-C++ ARC:
212    //   If we are binding a reference to a temporary that has ownership, we
213    //   need to perform retain/release operations on the temporary.
214    if (CGF.getContext().getLangOptions().ObjCAutoRefCount &&
215        E->getType()->isObjCLifetimeType() &&
216        (E->getType().getObjCLifetime() == Qualifiers::OCL_Strong ||
217         E->getType().getObjCLifetime() == Qualifiers::OCL_Weak ||
218         E->getType().getObjCLifetime() == Qualifiers::OCL_Autoreleasing))
219      ObjCARCReferenceLifetimeType = E->getType();
220
221    E = M->GetTemporaryExpr();
222  }
223
224  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
225    E = DAE->getExpr();
226
227  if (const ExprWithCleanups *TE = dyn_cast<ExprWithCleanups>(E)) {
228    CodeGenFunction::RunCleanupsScope Scope(CGF);
229
230    return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
231                                       ReferenceTemporary,
232                                       ReferenceTemporaryDtor,
233                                       ObjCARCReferenceLifetimeType,
234                                       InitializedDecl);
235  }
236
237  if (const ObjCPropertyRefExpr *PRE =
238      dyn_cast<ObjCPropertyRefExpr>(E->IgnoreParenImpCasts()))
239    if (PRE->getGetterResultType()->isReferenceType())
240      E = PRE;
241
242  RValue RV;
243  if (E->isGLValue()) {
244    // Emit the expression as an lvalue.
245    LValue LV = CGF.EmitLValue(E);
246    if (LV.isPropertyRef()) {
247      RV = CGF.EmitLoadOfPropertyRefLValue(LV);
248      return RV.getScalarVal();
249    }
250    if (LV.isSimple())
251      return LV.getAddress();
252
253    // We have to load the lvalue.
254    RV = CGF.EmitLoadOfLValue(LV);
255  } else {
256    if (!ObjCARCReferenceLifetimeType.isNull()) {
257      ReferenceTemporary = CreateReferenceTemporary(CGF,
258                                                  ObjCARCReferenceLifetimeType,
259                                                    InitializedDecl);
260
261
262      LValue RefTempDst = CGF.MakeAddrLValue(ReferenceTemporary,
263                                             ObjCARCReferenceLifetimeType);
264
265      CGF.EmitScalarInit(E, dyn_cast_or_null<ValueDecl>(InitializedDecl),
266                         RefTempDst, false);
267
268      bool ExtendsLifeOfTemporary = false;
269      if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
270        if (Var->extendsLifetimeOfTemporary())
271          ExtendsLifeOfTemporary = true;
272      } else if (InitializedDecl && isa<FieldDecl>(InitializedDecl)) {
273        ExtendsLifeOfTemporary = true;
274      }
275
276      if (!ExtendsLifeOfTemporary) {
277        // Since the lifetime of this temporary isn't going to be extended,
278        // we need to clean it up ourselves at the end of the full expression.
279        switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) {
280        case Qualifiers::OCL_None:
281        case Qualifiers::OCL_ExplicitNone:
282        case Qualifiers::OCL_Autoreleasing:
283          break;
284
285        case Qualifiers::OCL_Strong:
286          CGF.PushARCReleaseCleanup(CGF.getARCCleanupKind(),
287                                    ObjCARCReferenceLifetimeType,
288                                    ReferenceTemporary,
289                                    /*Precise lifetime=*/false,
290                                    /*For full expression=*/true);
291          break;
292
293        case Qualifiers::OCL_Weak:
294          CGF.PushARCWeakReleaseCleanup(NormalAndEHCleanup,
295                                        ObjCARCReferenceLifetimeType,
296                                        ReferenceTemporary,
297                                        /*For full expression=*/true);
298          break;
299        }
300
301        ObjCARCReferenceLifetimeType = QualType();
302      }
303
304      return ReferenceTemporary;
305    }
306
307    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
308    while (true) {
309      E = E->IgnoreParens();
310
311      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
312        if ((CE->getCastKind() == CK_DerivedToBase ||
313             CE->getCastKind() == CK_UncheckedDerivedToBase) &&
314            E->getType()->isRecordType()) {
315          E = CE->getSubExpr();
316          CXXRecordDecl *Derived
317            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
318          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
319          continue;
320        }
321
322        if (CE->getCastKind() == CK_NoOp) {
323          E = CE->getSubExpr();
324          continue;
325        }
326      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
327        if (!ME->isArrow() && ME->getBase()->isRValue()) {
328          assert(ME->getBase()->getType()->isRecordType());
329          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
330            E = ME->getBase();
331            Adjustments.push_back(SubobjectAdjustment(Field));
332            continue;
333          }
334        }
335      }
336
337      if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
338        if (opaque->getType()->isRecordType())
339          return CGF.EmitOpaqueValueLValue(opaque).getAddress();
340
341      // Nothing changed.
342      break;
343    }
344
345    // Create a reference temporary if necessary.
346    AggValueSlot AggSlot = AggValueSlot::ignored();
347    if (CGF.hasAggregateLLVMType(E->getType()) &&
348        !E->getType()->isAnyComplexType()) {
349      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
350                                                    InitializedDecl);
351      AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Qualifiers(),
352                                      InitializedDecl != 0);
353    }
354
355    if (InitializedDecl) {
356      // Get the destructor for the reference temporary.
357      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
358        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
359        if (!ClassDecl->hasTrivialDestructor())
360          ReferenceTemporaryDtor = ClassDecl->getDestructor();
361      }
362    }
363
364    RV = CGF.EmitAnyExpr(E, AggSlot);
365
366    // Check if need to perform derived-to-base casts and/or field accesses, to
367    // get from the temporary object we created (and, potentially, for which we
368    // extended the lifetime) to the subobject we're binding the reference to.
369    if (!Adjustments.empty()) {
370      llvm::Value *Object = RV.getAggregateAddr();
371      for (unsigned I = Adjustments.size(); I != 0; --I) {
372        SubobjectAdjustment &Adjustment = Adjustments[I-1];
373        switch (Adjustment.Kind) {
374        case SubobjectAdjustment::DerivedToBaseAdjustment:
375          Object =
376              CGF.GetAddressOfBaseClass(Object,
377                                        Adjustment.DerivedToBase.DerivedClass,
378                              Adjustment.DerivedToBase.BasePath->path_begin(),
379                              Adjustment.DerivedToBase.BasePath->path_end(),
380                                        /*NullCheckValue=*/false);
381          break;
382
383        case SubobjectAdjustment::FieldAdjustment: {
384          LValue LV =
385            CGF.EmitLValueForField(Object, Adjustment.Field, 0);
386          if (LV.isSimple()) {
387            Object = LV.getAddress();
388            break;
389          }
390
391          // For non-simple lvalues, we actually have to create a copy of
392          // the object we're binding to.
393          QualType T = Adjustment.Field->getType().getNonReferenceType()
394                                                  .getUnqualifiedType();
395          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
396          LValue TempLV = CGF.MakeAddrLValue(Object,
397                                             Adjustment.Field->getType());
398          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV), TempLV);
399          break;
400        }
401
402        }
403      }
404
405      return Object;
406    }
407  }
408
409  if (RV.isAggregate())
410    return RV.getAggregateAddr();
411
412  // Create a temporary variable that we can bind the reference to.
413  ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
414                                                InitializedDecl);
415
416
417  unsigned Alignment =
418    CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
419  if (RV.isScalar())
420    CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
421                          /*Volatile=*/false, Alignment, E->getType());
422  else
423    CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
424                           /*Volatile=*/false);
425  return ReferenceTemporary;
426}
427
428RValue
429CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E,
430                                            const NamedDecl *InitializedDecl) {
431  llvm::Value *ReferenceTemporary = 0;
432  const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
433  QualType ObjCARCReferenceLifetimeType;
434  llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
435                                                   ReferenceTemporaryDtor,
436                                                   ObjCARCReferenceLifetimeType,
437                                                   InitializedDecl);
438  if (!ReferenceTemporaryDtor && ObjCARCReferenceLifetimeType.isNull())
439    return RValue::get(Value);
440
441  // Make sure to call the destructor for the reference temporary.
442  const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl);
443  if (VD && VD->hasGlobalStorage()) {
444    if (ReferenceTemporaryDtor) {
445      llvm::Constant *DtorFn =
446        CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
447      EmitCXXGlobalDtorRegistration(DtorFn,
448                                    cast<llvm::Constant>(ReferenceTemporary));
449    } else {
450      assert(!ObjCARCReferenceLifetimeType.isNull());
451      // Note: We intentionally do not register a global "destructor" to
452      // release the object.
453    }
454
455    return RValue::get(Value);
456  }
457
458  if (ReferenceTemporaryDtor)
459    PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
460  else {
461    switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) {
462    case Qualifiers::OCL_None:
463      llvm_unreachable("Not a reference temporary that needs to be deallocated");
464      break;
465
466    case Qualifiers::OCL_ExplicitNone:
467    case Qualifiers::OCL_Autoreleasing:
468      // Nothing to do.
469      break;
470
471    case Qualifiers::OCL_Strong:
472      PushARCReleaseCleanup(getARCCleanupKind(), ObjCARCReferenceLifetimeType,
473                            ReferenceTemporary,
474                            VD && VD->hasAttr<ObjCPreciseLifetimeAttr>());
475      break;
476
477    case Qualifiers::OCL_Weak:
478      // __weak objects always get EH cleanups; otherwise, exceptions
479      // could cause really nasty crashes instead of mere leaks.
480      PushARCWeakReleaseCleanup(NormalAndEHCleanup,
481                                ObjCARCReferenceLifetimeType,
482                                ReferenceTemporary);
483      break;
484    }
485  }
486
487  return RValue::get(Value);
488}
489
490
491/// getAccessedFieldNo - Given an encoded value and a result number, return the
492/// input field number being accessed.
493unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
494                                             const llvm::Constant *Elts) {
495  if (isa<llvm::ConstantAggregateZero>(Elts))
496    return 0;
497
498  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
499}
500
501void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
502  if (!CatchUndefined)
503    return;
504
505  // This needs to be to the standard address space.
506  Address = Builder.CreateBitCast(Address, Int8PtrTy);
507
508  const llvm::Type *IntPtrT = IntPtrTy;
509  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
510
511  // In time, people may want to control this and use a 1 here.
512  llvm::Value *Arg = Builder.getFalse();
513  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
514  llvm::BasicBlock *Cont = createBasicBlock();
515  llvm::BasicBlock *Check = createBasicBlock();
516  llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
517  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
518
519  EmitBlock(Check);
520  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
521                                        llvm::ConstantInt::get(IntPtrTy, Size)),
522                       Cont, getTrapBB());
523  EmitBlock(Cont);
524}
525
526
527CodeGenFunction::ComplexPairTy CodeGenFunction::
528EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
529                         bool isInc, bool isPre) {
530  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
531                                            LV.isVolatileQualified());
532
533  llvm::Value *NextVal;
534  if (isa<llvm::IntegerType>(InVal.first->getType())) {
535    uint64_t AmountVal = isInc ? 1 : -1;
536    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
537
538    // Add the inc/dec to the real part.
539    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
540  } else {
541    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
542    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
543    if (!isInc)
544      FVal.changeSign();
545    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
546
547    // Add the inc/dec to the real part.
548    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
549  }
550
551  ComplexPairTy IncVal(NextVal, InVal.second);
552
553  // Store the updated result through the lvalue.
554  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
555
556  // If this is a postinc, return the value read from memory, otherwise use the
557  // updated value.
558  return isPre ? IncVal : InVal;
559}
560
561
562//===----------------------------------------------------------------------===//
563//                         LValue Expression Emission
564//===----------------------------------------------------------------------===//
565
566RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
567  if (Ty->isVoidType())
568    return RValue::get(0);
569
570  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
571    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
572    llvm::Value *U = llvm::UndefValue::get(EltTy);
573    return RValue::getComplex(std::make_pair(U, U));
574  }
575
576  // If this is a use of an undefined aggregate type, the aggregate must have an
577  // identifiable address.  Just because the contents of the value are undefined
578  // doesn't mean that the address can't be taken and compared.
579  if (hasAggregateLLVMType(Ty)) {
580    llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
581    return RValue::getAggregate(DestPtr);
582  }
583
584  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
585}
586
587RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
588                                              const char *Name) {
589  ErrorUnsupported(E, Name);
590  return GetUndefRValue(E->getType());
591}
592
593LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
594                                              const char *Name) {
595  ErrorUnsupported(E, Name);
596  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
597  return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType());
598}
599
600LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
601  LValue LV = EmitLValue(E);
602  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
603    EmitCheck(LV.getAddress(),
604              getContext().getTypeSizeInChars(E->getType()).getQuantity());
605  return LV;
606}
607
608/// EmitLValue - Emit code to compute a designator that specifies the location
609/// of the expression.
610///
611/// This can return one of two things: a simple address or a bitfield reference.
612/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
613/// an LLVM pointer type.
614///
615/// If this returns a bitfield reference, nothing about the pointee type of the
616/// LLVM value is known: For example, it may not be a pointer to an integer.
617///
618/// If this returns a normal address, and if the lvalue's C type is fixed size,
619/// this method guarantees that the returned pointer type will point to an LLVM
620/// type of the same size of the lvalue's type.  If the lvalue has a variable
621/// length type, this is not possible.
622///
623LValue CodeGenFunction::EmitLValue(const Expr *E) {
624  switch (E->getStmtClass()) {
625  default: return EmitUnsupportedLValue(E, "l-value expression");
626
627  case Expr::ObjCSelectorExprClass:
628  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
629  case Expr::ObjCIsaExprClass:
630    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
631  case Expr::BinaryOperatorClass:
632    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
633  case Expr::CompoundAssignOperatorClass:
634    if (!E->getType()->isAnyComplexType())
635      return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
636    return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
637  case Expr::CallExprClass:
638  case Expr::CXXMemberCallExprClass:
639  case Expr::CXXOperatorCallExprClass:
640    return EmitCallExprLValue(cast<CallExpr>(E));
641  case Expr::VAArgExprClass:
642    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
643  case Expr::DeclRefExprClass:
644    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
645  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
646  case Expr::GenericSelectionExprClass:
647    return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
648  case Expr::PredefinedExprClass:
649    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
650  case Expr::StringLiteralClass:
651    return EmitStringLiteralLValue(cast<StringLiteral>(E));
652  case Expr::ObjCEncodeExprClass:
653    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
654
655  case Expr::BlockDeclRefExprClass:
656    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
657
658  case Expr::CXXTemporaryObjectExprClass:
659  case Expr::CXXConstructExprClass:
660    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
661  case Expr::CXXBindTemporaryExprClass:
662    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
663  case Expr::ExprWithCleanupsClass:
664    return EmitExprWithCleanupsLValue(cast<ExprWithCleanups>(E));
665  case Expr::CXXScalarValueInitExprClass:
666    return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
667  case Expr::CXXDefaultArgExprClass:
668    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
669  case Expr::CXXTypeidExprClass:
670    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
671
672  case Expr::ObjCMessageExprClass:
673    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
674  case Expr::ObjCIvarRefExprClass:
675    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
676  case Expr::ObjCPropertyRefExprClass:
677    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
678  case Expr::StmtExprClass:
679    return EmitStmtExprLValue(cast<StmtExpr>(E));
680  case Expr::UnaryOperatorClass:
681    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
682  case Expr::ArraySubscriptExprClass:
683    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
684  case Expr::ExtVectorElementExprClass:
685    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
686  case Expr::MemberExprClass:
687    return EmitMemberExpr(cast<MemberExpr>(E));
688  case Expr::CompoundLiteralExprClass:
689    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
690  case Expr::ConditionalOperatorClass:
691    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
692  case Expr::BinaryConditionalOperatorClass:
693    return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
694  case Expr::ChooseExprClass:
695    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
696  case Expr::OpaqueValueExprClass:
697    return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
698  case Expr::ImplicitCastExprClass:
699  case Expr::CStyleCastExprClass:
700  case Expr::CXXFunctionalCastExprClass:
701  case Expr::CXXStaticCastExprClass:
702  case Expr::CXXDynamicCastExprClass:
703  case Expr::CXXReinterpretCastExprClass:
704  case Expr::CXXConstCastExprClass:
705  case Expr::ObjCBridgedCastExprClass:
706    return EmitCastLValue(cast<CastExpr>(E));
707
708  case Expr::MaterializeTemporaryExprClass:
709    return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
710  }
711}
712
713llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue) {
714  return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
715                          lvalue.getAlignment(), lvalue.getType(),
716                          lvalue.getTBAAInfo());
717}
718
719llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
720                                              unsigned Alignment, QualType Ty,
721                                              llvm::MDNode *TBAAInfo) {
722  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
723  if (Volatile)
724    Load->setVolatile(true);
725  if (Alignment)
726    Load->setAlignment(Alignment);
727  if (TBAAInfo)
728    CGM.DecorateInstruction(Load, TBAAInfo);
729
730  return EmitFromMemory(Load, Ty);
731}
732
733static bool isBooleanUnderlyingType(QualType Ty) {
734  if (const EnumType *ET = dyn_cast<EnumType>(Ty))
735    return ET->getDecl()->getIntegerType()->isBooleanType();
736  return false;
737}
738
739llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
740  // Bool has a different representation in memory than in registers.
741  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
742    // This should really always be an i1, but sometimes it's already
743    // an i8, and it's awkward to track those cases down.
744    if (Value->getType()->isIntegerTy(1))
745      return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool");
746    assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8");
747  }
748
749  return Value;
750}
751
752llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
753  // Bool has a different representation in memory than in registers.
754  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
755    assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8");
756    return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
757  }
758
759  return Value;
760}
761
762void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
763                                        bool Volatile, unsigned Alignment,
764                                        QualType Ty,
765                                        llvm::MDNode *TBAAInfo) {
766  Value = EmitToMemory(Value, Ty);
767  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
768  if (Alignment)
769    Store->setAlignment(Alignment);
770  if (TBAAInfo)
771    CGM.DecorateInstruction(Store, TBAAInfo);
772}
773
774void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue) {
775  EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
776                    lvalue.getAlignment(), lvalue.getType(),
777                    lvalue.getTBAAInfo());
778}
779
780/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
781/// method emits the address of the lvalue, then loads the result as an rvalue,
782/// returning the rvalue.
783RValue CodeGenFunction::EmitLoadOfLValue(LValue LV) {
784  if (LV.isObjCWeak()) {
785    // load of a __weak object.
786    llvm::Value *AddrWeakObj = LV.getAddress();
787    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
788                                                             AddrWeakObj));
789  }
790  if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak)
791    return RValue::get(EmitARCLoadWeak(LV.getAddress()));
792
793  if (LV.isSimple()) {
794    assert(!LV.getType()->isFunctionType());
795
796    // Everything needs a load.
797    return RValue::get(EmitLoadOfScalar(LV));
798  }
799
800  if (LV.isVectorElt()) {
801    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
802                                          LV.isVolatileQualified(), "tmp");
803    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
804                                                    "vecext"));
805  }
806
807  // If this is a reference to a subset of the elements of a vector, either
808  // shuffle the input or extract/insert them as appropriate.
809  if (LV.isExtVectorElt())
810    return EmitLoadOfExtVectorElementLValue(LV);
811
812  if (LV.isBitField())
813    return EmitLoadOfBitfieldLValue(LV);
814
815  assert(LV.isPropertyRef() && "Unknown LValue type!");
816  return EmitLoadOfPropertyRefLValue(LV);
817}
818
819RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV) {
820  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
821
822  // Get the output type.
823  const llvm::Type *ResLTy = ConvertType(LV.getType());
824  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
825
826  // Compute the result as an OR of all of the individual component accesses.
827  llvm::Value *Res = 0;
828  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
829    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
830
831    // Get the field pointer.
832    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
833
834    // Only offset by the field index if used, so that incoming values are not
835    // required to be structures.
836    if (AI.FieldIndex)
837      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
838
839    // Offset by the byte offset, if used.
840    if (!AI.FieldByteOffset.isZero()) {
841      Ptr = EmitCastToVoidPtr(Ptr);
842      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(),
843                                       "bf.field.offs");
844    }
845
846    // Cast to the access type.
847    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(getLLVMContext(),
848                                                     AI.AccessWidth,
849                       CGM.getContext().getTargetAddressSpace(LV.getType()));
850    Ptr = Builder.CreateBitCast(Ptr, PTy);
851
852    // Perform the load.
853    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
854    if (!AI.AccessAlignment.isZero())
855      Load->setAlignment(AI.AccessAlignment.getQuantity());
856
857    // Shift out unused low bits and mask out unused high bits.
858    llvm::Value *Val = Load;
859    if (AI.FieldBitStart)
860      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
861    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
862                                                            AI.TargetBitWidth),
863                            "bf.clear");
864
865    // Extend or truncate to the target size.
866    if (AI.AccessWidth < ResSizeInBits)
867      Val = Builder.CreateZExt(Val, ResLTy);
868    else if (AI.AccessWidth > ResSizeInBits)
869      Val = Builder.CreateTrunc(Val, ResLTy);
870
871    // Shift into place, and OR into the result.
872    if (AI.TargetBitOffset)
873      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
874    Res = Res ? Builder.CreateOr(Res, Val) : Val;
875  }
876
877  // If the bit-field is signed, perform the sign-extension.
878  //
879  // FIXME: This can easily be folded into the load of the high bits, which
880  // could also eliminate the mask of high bits in some situations.
881  if (Info.isSigned()) {
882    unsigned ExtraBits = ResSizeInBits - Info.getSize();
883    if (ExtraBits)
884      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
885                               ExtraBits, "bf.val.sext");
886  }
887
888  return RValue::get(Res);
889}
890
891// If this is a reference to a subset of the elements of a vector, create an
892// appropriate shufflevector.
893RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
894  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
895                                        LV.isVolatileQualified(), "tmp");
896
897  const llvm::Constant *Elts = LV.getExtVectorElts();
898
899  // If the result of the expression is a non-vector type, we must be extracting
900  // a single element.  Just codegen as an extractelement.
901  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
902  if (!ExprVT) {
903    unsigned InIdx = getAccessedFieldNo(0, Elts);
904    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
905    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
906  }
907
908  // Always use shuffle vector to try to retain the original program structure
909  unsigned NumResultElts = ExprVT->getNumElements();
910
911  llvm::SmallVector<llvm::Constant*, 4> Mask;
912  for (unsigned i = 0; i != NumResultElts; ++i) {
913    unsigned InIdx = getAccessedFieldNo(i, Elts);
914    Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx));
915  }
916
917  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
918  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
919                                    MaskV, "tmp");
920  return RValue::get(Vec);
921}
922
923
924
925/// EmitStoreThroughLValue - Store the specified rvalue into the specified
926/// lvalue, where both are guaranteed to the have the same type, and that type
927/// is 'Ty'.
928void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst) {
929  if (!Dst.isSimple()) {
930    if (Dst.isVectorElt()) {
931      // Read/modify/write the vector, inserting the new element.
932      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
933                                            Dst.isVolatileQualified(), "tmp");
934      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
935                                        Dst.getVectorIdx(), "vecins");
936      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
937      return;
938    }
939
940    // If this is an update of extended vector elements, insert them as
941    // appropriate.
942    if (Dst.isExtVectorElt())
943      return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
944
945    if (Dst.isBitField())
946      return EmitStoreThroughBitfieldLValue(Src, Dst);
947
948    assert(Dst.isPropertyRef() && "Unknown LValue type");
949    return EmitStoreThroughPropertyRefLValue(Src, Dst);
950  }
951
952  // There's special magic for assigning into an ARC-qualified l-value.
953  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
954    switch (Lifetime) {
955    case Qualifiers::OCL_None:
956      llvm_unreachable("present but none");
957
958    case Qualifiers::OCL_ExplicitNone:
959      // nothing special
960      break;
961
962    case Qualifiers::OCL_Strong:
963      EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
964      return;
965
966    case Qualifiers::OCL_Weak:
967      EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
968      return;
969
970    case Qualifiers::OCL_Autoreleasing:
971      Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
972                                                     Src.getScalarVal()));
973      // fall into the normal path
974      break;
975    }
976  }
977
978  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
979    // load of a __weak object.
980    llvm::Value *LvalueDst = Dst.getAddress();
981    llvm::Value *src = Src.getScalarVal();
982     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
983    return;
984  }
985
986  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
987    // load of a __strong object.
988    llvm::Value *LvalueDst = Dst.getAddress();
989    llvm::Value *src = Src.getScalarVal();
990    if (Dst.isObjCIvar()) {
991      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
992      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
993      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
994      llvm::Value *dst = RHS;
995      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
996      llvm::Value *LHS =
997        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
998      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
999      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1000                                              BytesBetween);
1001    } else if (Dst.isGlobalObjCRef()) {
1002      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1003                                                Dst.isThreadLocalRef());
1004    }
1005    else
1006      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1007    return;
1008  }
1009
1010  assert(Src.isScalar() && "Can't emit an agg store with this method");
1011  EmitStoreOfScalar(Src.getScalarVal(), Dst);
1012}
1013
1014void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1015                                                     llvm::Value **Result) {
1016  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1017
1018  // Get the output type.
1019  const llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1020  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
1021
1022  // Get the source value, truncated to the width of the bit-field.
1023  llvm::Value *SrcVal = Src.getScalarVal();
1024
1025  if (Dst.getType()->isBooleanType())
1026    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
1027
1028  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
1029                                                                Info.getSize()),
1030                             "bf.value");
1031
1032  // Return the new value of the bit-field, if requested.
1033  if (Result) {
1034    // Cast back to the proper type for result.
1035    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
1036    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
1037                                                   "bf.reload.val");
1038
1039    // Sign extend if necessary.
1040    if (Info.isSigned()) {
1041      unsigned ExtraBits = ResSizeInBits - Info.getSize();
1042      if (ExtraBits)
1043        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
1044                                       ExtraBits, "bf.reload.sext");
1045    }
1046
1047    *Result = ReloadVal;
1048  }
1049
1050  // Iterate over the components, writing each piece to memory.
1051  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
1052    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
1053
1054    // Get the field pointer.
1055    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
1056    unsigned addressSpace =
1057      cast<llvm::PointerType>(Ptr->getType())->getAddressSpace();
1058
1059    // Only offset by the field index if used, so that incoming values are not
1060    // required to be structures.
1061    if (AI.FieldIndex)
1062      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
1063
1064    // Offset by the byte offset, if used.
1065    if (!AI.FieldByteOffset.isZero()) {
1066      Ptr = EmitCastToVoidPtr(Ptr);
1067      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(),
1068                                       "bf.field.offs");
1069    }
1070
1071    // Cast to the access type.
1072    const llvm::Type *AccessLTy =
1073      llvm::Type::getIntNTy(getLLVMContext(), AI.AccessWidth);
1074
1075    const llvm::Type *PTy = AccessLTy->getPointerTo(addressSpace);
1076    Ptr = Builder.CreateBitCast(Ptr, PTy);
1077
1078    // Extract the piece of the bit-field value to write in this access, limited
1079    // to the values that are part of this access.
1080    llvm::Value *Val = SrcVal;
1081    if (AI.TargetBitOffset)
1082      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
1083    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
1084                                                            AI.TargetBitWidth));
1085
1086    // Extend or truncate to the access size.
1087    if (ResSizeInBits < AI.AccessWidth)
1088      Val = Builder.CreateZExt(Val, AccessLTy);
1089    else if (ResSizeInBits > AI.AccessWidth)
1090      Val = Builder.CreateTrunc(Val, AccessLTy);
1091
1092    // Shift into the position in memory.
1093    if (AI.FieldBitStart)
1094      Val = Builder.CreateShl(Val, AI.FieldBitStart);
1095
1096    // If necessary, load and OR in bits that are outside of the bit-field.
1097    if (AI.TargetBitWidth != AI.AccessWidth) {
1098      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
1099      if (!AI.AccessAlignment.isZero())
1100        Load->setAlignment(AI.AccessAlignment.getQuantity());
1101
1102      // Compute the mask for zeroing the bits that are part of the bit-field.
1103      llvm::APInt InvMask =
1104        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
1105                                 AI.FieldBitStart + AI.TargetBitWidth);
1106
1107      // Apply the mask and OR in to the value to write.
1108      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
1109    }
1110
1111    // Write the value.
1112    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
1113                                                 Dst.isVolatileQualified());
1114    if (!AI.AccessAlignment.isZero())
1115      Store->setAlignment(AI.AccessAlignment.getQuantity());
1116  }
1117}
1118
1119void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1120                                                               LValue Dst) {
1121  // This access turns into a read/modify/write of the vector.  Load the input
1122  // value now.
1123  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
1124                                        Dst.isVolatileQualified(), "tmp");
1125  const llvm::Constant *Elts = Dst.getExtVectorElts();
1126
1127  llvm::Value *SrcVal = Src.getScalarVal();
1128
1129  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
1130    unsigned NumSrcElts = VTy->getNumElements();
1131    unsigned NumDstElts =
1132       cast<llvm::VectorType>(Vec->getType())->getNumElements();
1133    if (NumDstElts == NumSrcElts) {
1134      // Use shuffle vector is the src and destination are the same number of
1135      // elements and restore the vector mask since it is on the side it will be
1136      // stored.
1137      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1138      for (unsigned i = 0; i != NumSrcElts; ++i) {
1139        unsigned InIdx = getAccessedFieldNo(i, Elts);
1140        Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
1141      }
1142
1143      llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1144      Vec = Builder.CreateShuffleVector(SrcVal,
1145                                        llvm::UndefValue::get(Vec->getType()),
1146                                        MaskV, "tmp");
1147    } else if (NumDstElts > NumSrcElts) {
1148      // Extended the source vector to the same length and then shuffle it
1149      // into the destination.
1150      // FIXME: since we're shuffling with undef, can we just use the indices
1151      //        into that?  This could be simpler.
1152      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1153      unsigned i;
1154      for (i = 0; i != NumSrcElts; ++i)
1155        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1156      for (; i != NumDstElts; ++i)
1157        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1158      llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1159      llvm::Value *ExtSrcVal =
1160        Builder.CreateShuffleVector(SrcVal,
1161                                    llvm::UndefValue::get(SrcVal->getType()),
1162                                    ExtMaskV, "tmp");
1163      // build identity
1164      llvm::SmallVector<llvm::Constant*, 4> Mask;
1165      for (unsigned i = 0; i != NumDstElts; ++i)
1166        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1167
1168      // modify when what gets shuffled in
1169      for (unsigned i = 0; i != NumSrcElts; ++i) {
1170        unsigned Idx = getAccessedFieldNo(i, Elts);
1171        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
1172      }
1173      llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1174      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
1175    } else {
1176      // We should never shorten the vector
1177      assert(0 && "unexpected shorten vector length");
1178    }
1179  } else {
1180    // If the Src is a scalar (not a vector) it must be updating one element.
1181    unsigned InIdx = getAccessedFieldNo(0, Elts);
1182    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
1183    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
1184  }
1185
1186  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
1187}
1188
1189// setObjCGCLValueClass - sets class of he lvalue for the purpose of
1190// generating write-barries API. It is currently a global, ivar,
1191// or neither.
1192static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1193                                 LValue &LV) {
1194  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
1195    return;
1196
1197  if (isa<ObjCIvarRefExpr>(E)) {
1198    LV.setObjCIvar(true);
1199    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
1200    LV.setBaseIvarExp(Exp->getBase());
1201    LV.setObjCArray(E->getType()->isArrayType());
1202    return;
1203  }
1204
1205  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
1206    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1207      if (VD->hasGlobalStorage()) {
1208        LV.setGlobalObjCRef(true);
1209        LV.setThreadLocalRef(VD->isThreadSpecified());
1210      }
1211    }
1212    LV.setObjCArray(E->getType()->isArrayType());
1213    return;
1214  }
1215
1216  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
1217    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1218    return;
1219  }
1220
1221  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
1222    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1223    if (LV.isObjCIvar()) {
1224      // If cast is to a structure pointer, follow gcc's behavior and make it
1225      // a non-ivar write-barrier.
1226      QualType ExpTy = E->getType();
1227      if (ExpTy->isPointerType())
1228        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1229      if (ExpTy->isRecordType())
1230        LV.setObjCIvar(false);
1231    }
1232    return;
1233  }
1234
1235  if (const GenericSelectionExpr *Exp = dyn_cast<GenericSelectionExpr>(E)) {
1236    setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
1237    return;
1238  }
1239
1240  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1241    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1242    return;
1243  }
1244
1245  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1246    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1247    return;
1248  }
1249
1250  if (const ObjCBridgedCastExpr *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
1251    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1252    return;
1253  }
1254
1255  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1256    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1257    if (LV.isObjCIvar() && !LV.isObjCArray())
1258      // Using array syntax to assigning to what an ivar points to is not
1259      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1260      LV.setObjCIvar(false);
1261    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1262      // Using array syntax to assigning to what global points to is not
1263      // same as assigning to the global itself. {id *G;} G[i] = 0;
1264      LV.setGlobalObjCRef(false);
1265    return;
1266  }
1267
1268  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1269    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1270    // We don't know if member is an 'ivar', but this flag is looked at
1271    // only in the context of LV.isObjCIvar().
1272    LV.setObjCArray(E->getType()->isArrayType());
1273    return;
1274  }
1275}
1276
1277static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1278                                      const Expr *E, const VarDecl *VD) {
1279  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1280         "Var decl must have external storage or be a file var decl!");
1281
1282  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1283  if (VD->getType()->isReferenceType())
1284    V = CGF.Builder.CreateLoad(V, "tmp");
1285  unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity();
1286  LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment);
1287  setObjCGCLValueClass(CGF.getContext(), E, LV);
1288  return LV;
1289}
1290
1291static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1292                                      const Expr *E, const FunctionDecl *FD) {
1293  llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
1294  if (!FD->hasPrototype()) {
1295    if (const FunctionProtoType *Proto =
1296            FD->getType()->getAs<FunctionProtoType>()) {
1297      // Ugly case: for a K&R-style definition, the type of the definition
1298      // isn't the same as the type of a use.  Correct for this with a
1299      // bitcast.
1300      QualType NoProtoType =
1301          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1302      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1303      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1304    }
1305  }
1306  unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity();
1307  return CGF.MakeAddrLValue(V, E->getType(), Alignment);
1308}
1309
1310LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1311  const NamedDecl *ND = E->getDecl();
1312  unsigned Alignment = getContext().getDeclAlign(ND).getQuantity();
1313
1314  if (ND->hasAttr<WeakRefAttr>()) {
1315    const ValueDecl *VD = cast<ValueDecl>(ND);
1316    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1317    return MakeAddrLValue(Aliasee, E->getType(), Alignment);
1318  }
1319
1320  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1321
1322    // Check if this is a global variable.
1323    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1324      return EmitGlobalVarDeclLValue(*this, E, VD);
1325
1326    bool NonGCable = VD->hasLocalStorage() &&
1327                     !VD->getType()->isReferenceType() &&
1328                     !VD->hasAttr<BlocksAttr>();
1329
1330    llvm::Value *V = LocalDeclMap[VD];
1331    if (!V && VD->isStaticLocal())
1332      V = CGM.getStaticLocalDeclAddress(VD);
1333    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1334
1335    if (VD->hasAttr<BlocksAttr>())
1336      V = BuildBlockByrefAddress(V, VD);
1337
1338    if (VD->getType()->isReferenceType())
1339      V = Builder.CreateLoad(V, "tmp");
1340
1341    LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
1342    if (NonGCable) {
1343      LV.getQuals().removeObjCGCAttr();
1344      LV.setNonGC(true);
1345    }
1346    setObjCGCLValueClass(getContext(), E, LV);
1347    return LV;
1348  }
1349
1350  if (const FunctionDecl *fn = dyn_cast<FunctionDecl>(ND))
1351    return EmitFunctionDeclLValue(*this, E, fn);
1352
1353  assert(false && "Unhandled DeclRefExpr");
1354
1355  // an invalid LValue, but the assert will
1356  // ensure that this point is never reached.
1357  return LValue();
1358}
1359
1360LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1361  unsigned Alignment =
1362    getContext().getDeclAlign(E->getDecl()).getQuantity();
1363  return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
1364}
1365
1366LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1367  // __extension__ doesn't affect lvalue-ness.
1368  if (E->getOpcode() == UO_Extension)
1369    return EmitLValue(E->getSubExpr());
1370
1371  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1372  switch (E->getOpcode()) {
1373  default: assert(0 && "Unknown unary operator lvalue!");
1374  case UO_Deref: {
1375    QualType T = E->getSubExpr()->getType()->getPointeeType();
1376    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1377
1378    LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
1379    LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
1380
1381    // We should not generate __weak write barrier on indirect reference
1382    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1383    // But, we continue to generate __strong write barrier on indirect write
1384    // into a pointer to object.
1385    if (getContext().getLangOptions().ObjC1 &&
1386        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1387        LV.isObjCWeak())
1388      LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1389    return LV;
1390  }
1391  case UO_Real:
1392  case UO_Imag: {
1393    LValue LV = EmitLValue(E->getSubExpr());
1394    assert(LV.isSimple() && "real/imag on non-ordinary l-value");
1395    llvm::Value *Addr = LV.getAddress();
1396
1397    // real and imag are valid on scalars.  This is a faster way of
1398    // testing that.
1399    if (!cast<llvm::PointerType>(Addr->getType())
1400           ->getElementType()->isStructTy()) {
1401      assert(E->getSubExpr()->getType()->isArithmeticType());
1402      return LV;
1403    }
1404
1405    assert(E->getSubExpr()->getType()->isAnyComplexType());
1406
1407    unsigned Idx = E->getOpcode() == UO_Imag;
1408    return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
1409                                                  Idx, "idx"),
1410                          ExprTy);
1411  }
1412  case UO_PreInc:
1413  case UO_PreDec: {
1414    LValue LV = EmitLValue(E->getSubExpr());
1415    bool isInc = E->getOpcode() == UO_PreInc;
1416
1417    if (E->getType()->isAnyComplexType())
1418      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1419    else
1420      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1421    return LV;
1422  }
1423  }
1424}
1425
1426LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1427  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
1428                        E->getType());
1429}
1430
1431LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1432  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1433                        E->getType());
1434}
1435
1436
1437LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1438  switch (E->getIdentType()) {
1439  default:
1440    return EmitUnsupportedLValue(E, "predefined expression");
1441
1442  case PredefinedExpr::Func:
1443  case PredefinedExpr::Function:
1444  case PredefinedExpr::PrettyFunction: {
1445    unsigned Type = E->getIdentType();
1446    std::string GlobalVarName;
1447
1448    switch (Type) {
1449    default: assert(0 && "Invalid type");
1450    case PredefinedExpr::Func:
1451      GlobalVarName = "__func__.";
1452      break;
1453    case PredefinedExpr::Function:
1454      GlobalVarName = "__FUNCTION__.";
1455      break;
1456    case PredefinedExpr::PrettyFunction:
1457      GlobalVarName = "__PRETTY_FUNCTION__.";
1458      break;
1459    }
1460
1461    llvm::StringRef FnName = CurFn->getName();
1462    if (FnName.startswith("\01"))
1463      FnName = FnName.substr(1);
1464    GlobalVarName += FnName;
1465
1466    const Decl *CurDecl = CurCodeDecl;
1467    if (CurDecl == 0)
1468      CurDecl = getContext().getTranslationUnitDecl();
1469
1470    std::string FunctionName =
1471        (isa<BlockDecl>(CurDecl)
1472         ? FnName.str()
1473         : PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl));
1474
1475    llvm::Constant *C =
1476      CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1477    return MakeAddrLValue(C, E->getType());
1478  }
1479  }
1480}
1481
1482llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1483  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1484
1485  // If we are not optimzing, don't collapse all calls to trap in the function
1486  // to the same call, that way, in the debugger they can see which operation
1487  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1488  // to just one per function to save on codesize.
1489  if (GCO.OptimizationLevel && TrapBB)
1490    return TrapBB;
1491
1492  llvm::BasicBlock *Cont = 0;
1493  if (HaveInsertPoint()) {
1494    Cont = createBasicBlock("cont");
1495    EmitBranch(Cont);
1496  }
1497  TrapBB = createBasicBlock("trap");
1498  EmitBlock(TrapBB);
1499
1500  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1501  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1502  TrapCall->setDoesNotReturn();
1503  TrapCall->setDoesNotThrow();
1504  Builder.CreateUnreachable();
1505
1506  if (Cont)
1507    EmitBlock(Cont);
1508  return TrapBB;
1509}
1510
1511/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1512/// array to pointer, return the array subexpression.
1513static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1514  // If this isn't just an array->pointer decay, bail out.
1515  const CastExpr *CE = dyn_cast<CastExpr>(E);
1516  if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay)
1517    return 0;
1518
1519  // If this is a decay from variable width array, bail out.
1520  const Expr *SubExpr = CE->getSubExpr();
1521  if (SubExpr->getType()->isVariableArrayType())
1522    return 0;
1523
1524  return SubExpr;
1525}
1526
1527LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1528  // The index must always be an integer, which is not an aggregate.  Emit it.
1529  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1530  QualType IdxTy  = E->getIdx()->getType();
1531  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
1532
1533  // If the base is a vector type, then we are forming a vector element lvalue
1534  // with this subscript.
1535  if (E->getBase()->getType()->isVectorType()) {
1536    // Emit the vector as an lvalue to get its address.
1537    LValue LHS = EmitLValue(E->getBase());
1538    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1539    Idx = Builder.CreateIntCast(Idx, Int32Ty, IdxSigned, "vidx");
1540    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1541                                 E->getBase()->getType());
1542  }
1543
1544  // Extend or truncate the index type to 32 or 64-bits.
1545  if (Idx->getType() != IntPtrTy)
1546    Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
1547
1548  // FIXME: As llvm implements the object size checking, this can come out.
1549  if (CatchUndefined) {
1550    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1551      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1552        if (ICE->getCastKind() == CK_ArrayToPointerDecay) {
1553          if (const ConstantArrayType *CAT
1554              = getContext().getAsConstantArrayType(DRE->getType())) {
1555            llvm::APInt Size = CAT->getSize();
1556            llvm::BasicBlock *Cont = createBasicBlock("cont");
1557            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1558                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1559                                 Cont, getTrapBB());
1560            EmitBlock(Cont);
1561          }
1562        }
1563      }
1564    }
1565  }
1566
1567  // We know that the pointer points to a type of the correct size, unless the
1568  // size is a VLA or Objective-C interface.
1569  llvm::Value *Address = 0;
1570  unsigned ArrayAlignment = 0;
1571  if (const VariableArrayType *vla =
1572        getContext().getAsVariableArrayType(E->getType())) {
1573    // The base must be a pointer, which is not an aggregate.  Emit
1574    // it.  It needs to be emitted first in case it's what captures
1575    // the VLA bounds.
1576    Address = EmitScalarExpr(E->getBase());
1577
1578    // The element count here is the total number of non-VLA elements.
1579    llvm::Value *numElements = getVLASize(vla).first;
1580
1581    // Effectively, the multiply by the VLA size is part of the GEP.
1582    // GEP indexes are signed, and scaling an index isn't permitted to
1583    // signed-overflow, so we use the same semantics for our explicit
1584    // multiply.  We suppress this if overflow is not undefined behavior.
1585    if (getLangOptions().isSignedOverflowDefined()) {
1586      Idx = Builder.CreateMul(Idx, numElements);
1587      Address = Builder.CreateGEP(Address, Idx, "arrayidx");
1588    } else {
1589      Idx = Builder.CreateNSWMul(Idx, numElements);
1590      Address = Builder.CreateInBoundsGEP(Address, Idx, "arrayidx");
1591    }
1592  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1593    // Indexing over an interface, as in "NSString *P; P[4];"
1594    llvm::Value *InterfaceSize =
1595      llvm::ConstantInt::get(Idx->getType(),
1596          getContext().getTypeSizeInChars(OIT).getQuantity());
1597
1598    Idx = Builder.CreateMul(Idx, InterfaceSize);
1599
1600    // The base must be a pointer, which is not an aggregate.  Emit it.
1601    llvm::Value *Base = EmitScalarExpr(E->getBase());
1602    Address = EmitCastToVoidPtr(Base);
1603    Address = Builder.CreateGEP(Address, Idx, "arrayidx");
1604    Address = Builder.CreateBitCast(Address, Base->getType());
1605  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1606    // If this is A[i] where A is an array, the frontend will have decayed the
1607    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1608    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1609    // "gep x, i" here.  Emit one "gep A, 0, i".
1610    assert(Array->getType()->isArrayType() &&
1611           "Array to pointer decay must have array source type!");
1612    LValue ArrayLV = EmitLValue(Array);
1613    llvm::Value *ArrayPtr = ArrayLV.getAddress();
1614    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1615    llvm::Value *Args[] = { Zero, Idx };
1616
1617    // Propagate the alignment from the array itself to the result.
1618    ArrayAlignment = ArrayLV.getAlignment();
1619
1620    if (getContext().getLangOptions().isSignedOverflowDefined())
1621      Address = Builder.CreateGEP(ArrayPtr, Args, Args+2, "arrayidx");
1622    else
1623      Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1624  } else {
1625    // The base must be a pointer, which is not an aggregate.  Emit it.
1626    llvm::Value *Base = EmitScalarExpr(E->getBase());
1627    if (getContext().getLangOptions().isSignedOverflowDefined())
1628      Address = Builder.CreateGEP(Base, Idx, "arrayidx");
1629    else
1630      Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1631  }
1632
1633  QualType T = E->getBase()->getType()->getPointeeType();
1634  assert(!T.isNull() &&
1635         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1636
1637  // Limit the alignment to that of the result type.
1638  if (ArrayAlignment) {
1639    unsigned Align = getContext().getTypeAlignInChars(T).getQuantity();
1640    ArrayAlignment = std::min(Align, ArrayAlignment);
1641  }
1642
1643  LValue LV = MakeAddrLValue(Address, T, ArrayAlignment);
1644  LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
1645
1646  if (getContext().getLangOptions().ObjC1 &&
1647      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1648    LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1649    setObjCGCLValueClass(getContext(), E, LV);
1650  }
1651  return LV;
1652}
1653
1654static
1655llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1656                                       llvm::SmallVector<unsigned, 4> &Elts) {
1657  llvm::SmallVector<llvm::Constant*, 4> CElts;
1658
1659  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1660  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1661    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1662
1663  return llvm::ConstantVector::get(CElts);
1664}
1665
1666LValue CodeGenFunction::
1667EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1668  // Emit the base vector as an l-value.
1669  LValue Base;
1670
1671  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1672  if (E->isArrow()) {
1673    // If it is a pointer to a vector, emit the address and form an lvalue with
1674    // it.
1675    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1676    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1677    Base = MakeAddrLValue(Ptr, PT->getPointeeType());
1678    Base.getQuals().removeObjCGCAttr();
1679  } else if (E->getBase()->isGLValue()) {
1680    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1681    // emit the base as an lvalue.
1682    assert(E->getBase()->getType()->isVectorType());
1683    Base = EmitLValue(E->getBase());
1684  } else {
1685    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1686    assert(E->getBase()->getType()->isVectorType() &&
1687           "Result must be a vector");
1688    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1689
1690    // Store the vector to memory (because LValue wants an address).
1691    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1692    Builder.CreateStore(Vec, VecMem);
1693    Base = MakeAddrLValue(VecMem, E->getBase()->getType());
1694  }
1695
1696  QualType type =
1697    E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
1698
1699  // Encode the element access list into a vector of unsigned indices.
1700  llvm::SmallVector<unsigned, 4> Indices;
1701  E->getEncodedElementAccess(Indices);
1702
1703  if (Base.isSimple()) {
1704    llvm::Constant *CV = GenerateConstantVector(getLLVMContext(), Indices);
1705    return LValue::MakeExtVectorElt(Base.getAddress(), CV, type);
1706  }
1707  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1708
1709  llvm::Constant *BaseElts = Base.getExtVectorElts();
1710  llvm::SmallVector<llvm::Constant *, 4> CElts;
1711
1712  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1713    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1714      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1715    else
1716      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1717  }
1718  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
1719  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV, type);
1720}
1721
1722LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1723  bool isNonGC = false;
1724  Expr *BaseExpr = E->getBase();
1725  llvm::Value *BaseValue = NULL;
1726  Qualifiers BaseQuals;
1727
1728  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1729  if (E->isArrow()) {
1730    BaseValue = EmitScalarExpr(BaseExpr);
1731    const PointerType *PTy =
1732      BaseExpr->getType()->getAs<PointerType>();
1733    BaseQuals = PTy->getPointeeType().getQualifiers();
1734  } else {
1735    LValue BaseLV = EmitLValue(BaseExpr);
1736    if (BaseLV.isNonGC())
1737      isNonGC = true;
1738    // FIXME: this isn't right for bitfields.
1739    BaseValue = BaseLV.getAddress();
1740    QualType BaseTy = BaseExpr->getType();
1741    BaseQuals = BaseTy.getQualifiers();
1742  }
1743
1744  NamedDecl *ND = E->getMemberDecl();
1745  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1746    LValue LV = EmitLValueForField(BaseValue, Field,
1747                                   BaseQuals.getCVRQualifiers());
1748    LV.setNonGC(isNonGC);
1749    setObjCGCLValueClass(getContext(), E, LV);
1750    return LV;
1751  }
1752
1753  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1754    return EmitGlobalVarDeclLValue(*this, E, VD);
1755
1756  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1757    return EmitFunctionDeclLValue(*this, E, FD);
1758
1759  assert(false && "Unhandled member declaration!");
1760  return LValue();
1761}
1762
1763LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue,
1764                                              const FieldDecl *Field,
1765                                              unsigned CVRQualifiers) {
1766  const CGRecordLayout &RL =
1767    CGM.getTypes().getCGRecordLayout(Field->getParent());
1768  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1769  return LValue::MakeBitfield(BaseValue, Info,
1770                          Field->getType().withCVRQualifiers(CVRQualifiers));
1771}
1772
1773/// EmitLValueForAnonRecordField - Given that the field is a member of
1774/// an anonymous struct or union buried inside a record, and given
1775/// that the base value is a pointer to the enclosing record, derive
1776/// an lvalue for the ultimate field.
1777LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1778                                             const IndirectFieldDecl *Field,
1779                                                     unsigned CVRQualifiers) {
1780  IndirectFieldDecl::chain_iterator I = Field->chain_begin(),
1781    IEnd = Field->chain_end();
1782  while (true) {
1783    LValue LV = EmitLValueForField(BaseValue, cast<FieldDecl>(*I),
1784                                   CVRQualifiers);
1785    if (++I == IEnd) return LV;
1786
1787    assert(LV.isSimple());
1788    BaseValue = LV.getAddress();
1789    CVRQualifiers |= LV.getVRQualifiers();
1790  }
1791}
1792
1793LValue CodeGenFunction::EmitLValueForField(llvm::Value *baseAddr,
1794                                           const FieldDecl *field,
1795                                           unsigned cvr) {
1796  if (field->isBitField())
1797    return EmitLValueForBitfield(baseAddr, field, cvr);
1798
1799  const RecordDecl *rec = field->getParent();
1800  QualType type = field->getType();
1801
1802  bool mayAlias = rec->hasAttr<MayAliasAttr>();
1803
1804  llvm::Value *addr;
1805  if (rec->isUnion()) {
1806    // For unions, we just cast to the appropriate type.
1807    assert(!type->isReferenceType() && "union has reference member");
1808
1809    const llvm::Type *llvmType = CGM.getTypes().ConvertTypeForMem(type);
1810    unsigned AS =
1811      cast<llvm::PointerType>(baseAddr->getType())->getAddressSpace();
1812    addr = Builder.CreateBitCast(baseAddr, llvmType->getPointerTo(AS),
1813                                 field->getName());
1814  } else {
1815    // For structs, we GEP to the field that the record layout suggests.
1816    unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
1817    addr = Builder.CreateStructGEP(baseAddr, idx, field->getName());
1818
1819    // If this is a reference field, load the reference right now.
1820    if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
1821      llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
1822      if (cvr & Qualifiers::Volatile) load->setVolatile(true);
1823
1824      if (CGM.shouldUseTBAA()) {
1825        llvm::MDNode *tbaa;
1826        if (mayAlias)
1827          tbaa = CGM.getTBAAInfo(getContext().CharTy);
1828        else
1829          tbaa = CGM.getTBAAInfo(type);
1830        CGM.DecorateInstruction(load, tbaa);
1831      }
1832
1833      addr = load;
1834      mayAlias = false;
1835      type = refType->getPointeeType();
1836      cvr = 0; // qualifiers don't recursively apply to referencee
1837    }
1838  }
1839
1840  unsigned alignment = getContext().getDeclAlign(field).getQuantity();
1841  LValue LV = MakeAddrLValue(addr, type, alignment);
1842  LV.getQuals().addCVRQualifiers(cvr);
1843
1844  // __weak attribute on a field is ignored.
1845  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
1846    LV.getQuals().removeObjCGCAttr();
1847
1848  // Fields of may_alias structs act like 'char' for TBAA purposes.
1849  // FIXME: this should get propagated down through anonymous structs
1850  // and unions.
1851  if (mayAlias && LV.getTBAAInfo())
1852    LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
1853
1854  return LV;
1855}
1856
1857LValue
1858CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue,
1859                                                  const FieldDecl *Field,
1860                                                  unsigned CVRQualifiers) {
1861  QualType FieldType = Field->getType();
1862
1863  if (!FieldType->isReferenceType())
1864    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1865
1866  const CGRecordLayout &RL =
1867    CGM.getTypes().getCGRecordLayout(Field->getParent());
1868  unsigned idx = RL.getLLVMFieldNo(Field);
1869  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1870
1871  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1872
1873  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1874  return MakeAddrLValue(V, FieldType, Alignment);
1875}
1876
1877LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
1878  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1879  const Expr *InitExpr = E->getInitializer();
1880  LValue Result = MakeAddrLValue(DeclPtr, E->getType());
1881
1882  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
1883                   /*Init*/ true);
1884
1885  return Result;
1886}
1887
1888LValue CodeGenFunction::
1889EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
1890  if (!expr->isGLValue()) {
1891    // ?: here should be an aggregate.
1892    assert((hasAggregateLLVMType(expr->getType()) &&
1893            !expr->getType()->isAnyComplexType()) &&
1894           "Unexpected conditional operator!");
1895    return EmitAggExprToLValue(expr);
1896  }
1897
1898  const Expr *condExpr = expr->getCond();
1899  bool CondExprBool;
1900  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
1901    const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
1902    if (!CondExprBool) std::swap(live, dead);
1903
1904    if (!ContainsLabel(dead))
1905      return EmitLValue(live);
1906  }
1907
1908  OpaqueValueMapping binding(*this, expr);
1909
1910  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
1911  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
1912  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
1913
1914  ConditionalEvaluation eval(*this);
1915  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock);
1916
1917  // Any temporaries created here are conditional.
1918  EmitBlock(lhsBlock);
1919  eval.begin(*this);
1920  LValue lhs = EmitLValue(expr->getTrueExpr());
1921  eval.end(*this);
1922
1923  if (!lhs.isSimple())
1924    return EmitUnsupportedLValue(expr, "conditional operator");
1925
1926  lhsBlock = Builder.GetInsertBlock();
1927  Builder.CreateBr(contBlock);
1928
1929  // Any temporaries created here are conditional.
1930  EmitBlock(rhsBlock);
1931  eval.begin(*this);
1932  LValue rhs = EmitLValue(expr->getFalseExpr());
1933  eval.end(*this);
1934  if (!rhs.isSimple())
1935    return EmitUnsupportedLValue(expr, "conditional operator");
1936  rhsBlock = Builder.GetInsertBlock();
1937
1938  EmitBlock(contBlock);
1939
1940  llvm::PHINode *phi = Builder.CreatePHI(lhs.getAddress()->getType(), 2,
1941                                         "cond-lvalue");
1942  phi->addIncoming(lhs.getAddress(), lhsBlock);
1943  phi->addIncoming(rhs.getAddress(), rhsBlock);
1944  return MakeAddrLValue(phi, expr->getType());
1945}
1946
1947/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1948/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1949/// otherwise if a cast is needed by the code generator in an lvalue context,
1950/// then it must mean that we need the address of an aggregate in order to
1951/// access one of its fields.  This can happen for all the reasons that casts
1952/// are permitted with aggregate result, including noop aggregate casts, and
1953/// cast from scalar to union.
1954LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1955  switch (E->getCastKind()) {
1956  case CK_ToVoid:
1957    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1958
1959  case CK_Dependent:
1960    llvm_unreachable("dependent cast kind in IR gen!");
1961
1962  case CK_GetObjCProperty: {
1963    LValue LV = EmitLValue(E->getSubExpr());
1964    assert(LV.isPropertyRef());
1965    RValue RV = EmitLoadOfPropertyRefLValue(LV);
1966
1967    // Property is an aggregate r-value.
1968    if (RV.isAggregate()) {
1969      return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
1970    }
1971
1972    // Implicit property returns an l-value.
1973    assert(RV.isScalar());
1974    return MakeAddrLValue(RV.getScalarVal(), E->getSubExpr()->getType());
1975  }
1976
1977  case CK_NoOp:
1978  case CK_LValueToRValue:
1979    if (!E->getSubExpr()->Classify(getContext()).isPRValue()
1980        || E->getType()->isRecordType())
1981      return EmitLValue(E->getSubExpr());
1982    // Fall through to synthesize a temporary.
1983
1984  case CK_BitCast:
1985  case CK_ArrayToPointerDecay:
1986  case CK_FunctionToPointerDecay:
1987  case CK_NullToMemberPointer:
1988  case CK_NullToPointer:
1989  case CK_IntegralToPointer:
1990  case CK_PointerToIntegral:
1991  case CK_PointerToBoolean:
1992  case CK_VectorSplat:
1993  case CK_IntegralCast:
1994  case CK_IntegralToBoolean:
1995  case CK_IntegralToFloating:
1996  case CK_FloatingToIntegral:
1997  case CK_FloatingToBoolean:
1998  case CK_FloatingCast:
1999  case CK_FloatingRealToComplex:
2000  case CK_FloatingComplexToReal:
2001  case CK_FloatingComplexToBoolean:
2002  case CK_FloatingComplexCast:
2003  case CK_FloatingComplexToIntegralComplex:
2004  case CK_IntegralRealToComplex:
2005  case CK_IntegralComplexToReal:
2006  case CK_IntegralComplexToBoolean:
2007  case CK_IntegralComplexCast:
2008  case CK_IntegralComplexToFloatingComplex:
2009  case CK_DerivedToBaseMemberPointer:
2010  case CK_BaseToDerivedMemberPointer:
2011  case CK_MemberPointerToBoolean:
2012  case CK_AnyPointerToBlockPointerCast:
2013  case CK_ObjCProduceObject:
2014  case CK_ObjCConsumeObject: {
2015    // These casts only produce lvalues when we're binding a reference to a
2016    // temporary realized from a (converted) pure rvalue. Emit the expression
2017    // as a value, copy it into a temporary, and return an lvalue referring to
2018    // that temporary.
2019    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
2020    EmitAnyExprToMem(E, V, E->getType().getQualifiers(), false);
2021    return MakeAddrLValue(V, E->getType());
2022  }
2023
2024  case CK_Dynamic: {
2025    LValue LV = EmitLValue(E->getSubExpr());
2026    llvm::Value *V = LV.getAddress();
2027    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
2028    return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
2029  }
2030
2031  case CK_ConstructorConversion:
2032  case CK_UserDefinedConversion:
2033  case CK_AnyPointerToObjCPointerCast:
2034    return EmitLValue(E->getSubExpr());
2035
2036  case CK_UncheckedDerivedToBase:
2037  case CK_DerivedToBase: {
2038    const RecordType *DerivedClassTy =
2039      E->getSubExpr()->getType()->getAs<RecordType>();
2040    CXXRecordDecl *DerivedClassDecl =
2041      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
2042
2043    LValue LV = EmitLValue(E->getSubExpr());
2044    llvm::Value *This = LV.getAddress();
2045
2046    // Perform the derived-to-base conversion
2047    llvm::Value *Base =
2048      GetAddressOfBaseClass(This, DerivedClassDecl,
2049                            E->path_begin(), E->path_end(),
2050                            /*NullCheckValue=*/false);
2051
2052    return MakeAddrLValue(Base, E->getType());
2053  }
2054  case CK_ToUnion:
2055    return EmitAggExprToLValue(E);
2056  case CK_BaseToDerived: {
2057    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
2058    CXXRecordDecl *DerivedClassDecl =
2059      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
2060
2061    LValue LV = EmitLValue(E->getSubExpr());
2062
2063    // Perform the base-to-derived conversion
2064    llvm::Value *Derived =
2065      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
2066                               E->path_begin(), E->path_end(),
2067                               /*NullCheckValue=*/false);
2068
2069    return MakeAddrLValue(Derived, E->getType());
2070  }
2071  case CK_LValueBitCast: {
2072    // This must be a reinterpret_cast (or c-style equivalent).
2073    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
2074
2075    LValue LV = EmitLValue(E->getSubExpr());
2076    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
2077                                           ConvertType(CE->getTypeAsWritten()));
2078    return MakeAddrLValue(V, E->getType());
2079  }
2080  case CK_ObjCObjectLValueCast: {
2081    LValue LV = EmitLValue(E->getSubExpr());
2082    QualType ToType = getContext().getLValueReferenceType(E->getType());
2083    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
2084                                           ConvertType(ToType));
2085    return MakeAddrLValue(V, E->getType());
2086  }
2087  }
2088
2089  llvm_unreachable("Unhandled lvalue cast kind?");
2090}
2091
2092LValue CodeGenFunction::EmitNullInitializationLValue(
2093                                              const CXXScalarValueInitExpr *E) {
2094  QualType Ty = E->getType();
2095  LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
2096  EmitNullInitialization(LV.getAddress(), Ty);
2097  return LV;
2098}
2099
2100LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
2101  assert(e->isGLValue() || e->getType()->isRecordType());
2102  return getOpaqueLValueMapping(e);
2103}
2104
2105LValue CodeGenFunction::EmitMaterializeTemporaryExpr(
2106                                           const MaterializeTemporaryExpr *E) {
2107  RValue RV = EmitReferenceBindingToExpr(E->GetTemporaryExpr(),
2108                                         /*InitializedDecl=*/0);
2109  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2110}
2111
2112
2113//===--------------------------------------------------------------------===//
2114//                             Expression Emission
2115//===--------------------------------------------------------------------===//
2116
2117RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
2118                                     ReturnValueSlot ReturnValue) {
2119  if (CGDebugInfo *DI = getDebugInfo()) {
2120    DI->setLocation(E->getLocStart());
2121    DI->UpdateLineDirectiveRegion(Builder);
2122    DI->EmitStopPoint(Builder);
2123  }
2124
2125  // Builtins never have block type.
2126  if (E->getCallee()->getType()->isBlockPointerType())
2127    return EmitBlockCallExpr(E, ReturnValue);
2128
2129  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
2130    return EmitCXXMemberCallExpr(CE, ReturnValue);
2131
2132  const Decl *TargetDecl = 0;
2133  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
2134    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
2135      TargetDecl = DRE->getDecl();
2136      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
2137        if (unsigned builtinID = FD->getBuiltinID())
2138          return EmitBuiltinExpr(FD, builtinID, E);
2139    }
2140  }
2141
2142  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
2143    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
2144      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
2145
2146  if (const CXXPseudoDestructorExpr *PseudoDtor
2147          = dyn_cast<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
2148    QualType DestroyedType = PseudoDtor->getDestroyedType();
2149    if (getContext().getLangOptions().ObjCAutoRefCount &&
2150        DestroyedType->isObjCLifetimeType() &&
2151        (DestroyedType.getObjCLifetime() == Qualifiers::OCL_Strong ||
2152         DestroyedType.getObjCLifetime() == Qualifiers::OCL_Weak)) {
2153      // Automatic Reference Counting:
2154      //   If the pseudo-expression names a retainable object with weak or
2155      //   strong lifetime, the object shall be released.
2156      Expr *BaseExpr = PseudoDtor->getBase();
2157      llvm::Value *BaseValue = NULL;
2158      Qualifiers BaseQuals;
2159
2160      // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
2161      if (PseudoDtor->isArrow()) {
2162        BaseValue = EmitScalarExpr(BaseExpr);
2163        const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>();
2164        BaseQuals = PTy->getPointeeType().getQualifiers();
2165      } else {
2166        LValue BaseLV = EmitLValue(BaseExpr);
2167        BaseValue = BaseLV.getAddress();
2168        QualType BaseTy = BaseExpr->getType();
2169        BaseQuals = BaseTy.getQualifiers();
2170      }
2171
2172      switch (PseudoDtor->getDestroyedType().getObjCLifetime()) {
2173      case Qualifiers::OCL_None:
2174      case Qualifiers::OCL_ExplicitNone:
2175      case Qualifiers::OCL_Autoreleasing:
2176        break;
2177
2178      case Qualifiers::OCL_Strong:
2179        EmitARCRelease(Builder.CreateLoad(BaseValue,
2180                          PseudoDtor->getDestroyedType().isVolatileQualified()),
2181                       /*precise*/ true);
2182        break;
2183
2184      case Qualifiers::OCL_Weak:
2185        EmitARCDestroyWeak(BaseValue);
2186        break;
2187      }
2188    } else {
2189      // C++ [expr.pseudo]p1:
2190      //   The result shall only be used as the operand for the function call
2191      //   operator (), and the result of such a call has type void. The only
2192      //   effect is the evaluation of the postfix-expression before the dot or
2193      //   arrow.
2194      EmitScalarExpr(E->getCallee());
2195    }
2196
2197    return RValue::get(0);
2198  }
2199
2200  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
2201  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
2202                  E->arg_begin(), E->arg_end(), TargetDecl);
2203}
2204
2205LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
2206  // Comma expressions just emit their LHS then their RHS as an l-value.
2207  if (E->getOpcode() == BO_Comma) {
2208    EmitIgnoredExpr(E->getLHS());
2209    EnsureInsertPoint();
2210    return EmitLValue(E->getRHS());
2211  }
2212
2213  if (E->getOpcode() == BO_PtrMemD ||
2214      E->getOpcode() == BO_PtrMemI)
2215    return EmitPointerToDataMemberBinaryExpr(E);
2216
2217  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
2218
2219  // Note that in all of these cases, __block variables need the RHS
2220  // evaluated first just in case the variable gets moved by the RHS.
2221
2222  if (!hasAggregateLLVMType(E->getType())) {
2223    switch (E->getLHS()->getType().getObjCLifetime()) {
2224    case Qualifiers::OCL_Strong:
2225      return EmitARCStoreStrong(E, /*ignored*/ false).first;
2226
2227    case Qualifiers::OCL_Autoreleasing:
2228      return EmitARCStoreAutoreleasing(E).first;
2229
2230    // No reason to do any of these differently.
2231    case Qualifiers::OCL_None:
2232    case Qualifiers::OCL_ExplicitNone:
2233    case Qualifiers::OCL_Weak:
2234      break;
2235    }
2236
2237    RValue RV = EmitAnyExpr(E->getRHS());
2238    LValue LV = EmitLValue(E->getLHS());
2239    EmitStoreThroughLValue(RV, LV);
2240    return LV;
2241  }
2242
2243  if (E->getType()->isAnyComplexType())
2244    return EmitComplexAssignmentLValue(E);
2245
2246  return EmitAggExprToLValue(E);
2247}
2248
2249LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
2250  RValue RV = EmitCallExpr(E);
2251
2252  if (!RV.isScalar())
2253    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2254
2255  assert(E->getCallReturnType()->isReferenceType() &&
2256         "Can't have a scalar return unless the return type is a "
2257         "reference type!");
2258
2259  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2260}
2261
2262LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
2263  // FIXME: This shouldn't require another copy.
2264  return EmitAggExprToLValue(E);
2265}
2266
2267LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
2268  assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
2269         && "binding l-value to type which needs a temporary");
2270  AggValueSlot Slot = CreateAggTemp(E->getType(), "tmp");
2271  EmitCXXConstructExpr(E, Slot);
2272  return MakeAddrLValue(Slot.getAddr(), E->getType());
2273}
2274
2275LValue
2276CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
2277  return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
2278}
2279
2280LValue
2281CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
2282  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
2283  Slot.setLifetimeExternallyManaged();
2284  EmitAggExpr(E->getSubExpr(), Slot);
2285  EmitCXXTemporary(E->getTemporary(), Slot.getAddr());
2286  return MakeAddrLValue(Slot.getAddr(), E->getType());
2287}
2288
2289LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
2290  RValue RV = EmitObjCMessageExpr(E);
2291
2292  if (!RV.isScalar())
2293    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2294
2295  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2296         "Can't have a scalar return unless the return type is a "
2297         "reference type!");
2298
2299  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2300}
2301
2302LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2303  llvm::Value *V =
2304    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2305  return MakeAddrLValue(V, E->getType());
2306}
2307
2308llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2309                                             const ObjCIvarDecl *Ivar) {
2310  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2311}
2312
2313LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2314                                          llvm::Value *BaseValue,
2315                                          const ObjCIvarDecl *Ivar,
2316                                          unsigned CVRQualifiers) {
2317  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2318                                                   Ivar, CVRQualifiers);
2319}
2320
2321LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2322  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2323  llvm::Value *BaseValue = 0;
2324  const Expr *BaseExpr = E->getBase();
2325  Qualifiers BaseQuals;
2326  QualType ObjectTy;
2327  if (E->isArrow()) {
2328    BaseValue = EmitScalarExpr(BaseExpr);
2329    ObjectTy = BaseExpr->getType()->getPointeeType();
2330    BaseQuals = ObjectTy.getQualifiers();
2331  } else {
2332    LValue BaseLV = EmitLValue(BaseExpr);
2333    // FIXME: this isn't right for bitfields.
2334    BaseValue = BaseLV.getAddress();
2335    ObjectTy = BaseExpr->getType();
2336    BaseQuals = ObjectTy.getQualifiers();
2337  }
2338
2339  LValue LV =
2340    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2341                      BaseQuals.getCVRQualifiers());
2342  setObjCGCLValueClass(getContext(), E, LV);
2343  return LV;
2344}
2345
2346LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2347  // Can only get l-value for message expression returning aggregate type
2348  RValue RV = EmitAnyExprToTemp(E);
2349  return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2350}
2351
2352RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2353                                 ReturnValueSlot ReturnValue,
2354                                 CallExpr::const_arg_iterator ArgBeg,
2355                                 CallExpr::const_arg_iterator ArgEnd,
2356                                 const Decl *TargetDecl) {
2357  // Get the actual function type. The callee type will always be a pointer to
2358  // function type or a block pointer type.
2359  assert(CalleeType->isFunctionPointerType() &&
2360         "Call must have function pointer type!");
2361
2362  CalleeType = getContext().getCanonicalType(CalleeType);
2363
2364  const FunctionType *FnType
2365    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2366
2367  CallArgList Args;
2368  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2369
2370  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2371                  Callee, ReturnValue, Args, TargetDecl);
2372}
2373
2374LValue CodeGenFunction::
2375EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2376  llvm::Value *BaseV;
2377  if (E->getOpcode() == BO_PtrMemI)
2378    BaseV = EmitScalarExpr(E->getLHS());
2379  else
2380    BaseV = EmitLValue(E->getLHS()).getAddress();
2381
2382  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2383
2384  const MemberPointerType *MPT
2385    = E->getRHS()->getType()->getAs<MemberPointerType>();
2386
2387  llvm::Value *AddV =
2388    CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT);
2389
2390  return MakeAddrLValue(AddV, MPT->getPointeeType());
2391}
2392