CGExpr.cpp revision 9f4f7cfe40edd5ed9d8ea7b8ce7c3dd988c7e310
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 "CGRecordLayout.h"
18#include "CGObjCRuntime.h"
19#include "clang/AST/ASTContext.h"
20#include "clang/AST/DeclObjC.h"
21#include "llvm/Intrinsics.h"
22#include "clang/Frontend/CodeGenOptions.h"
23#include "llvm/Target/TargetData.h"
24using namespace clang;
25using namespace CodeGen;
26
27//===--------------------------------------------------------------------===//
28//                        Miscellaneous Helper Methods
29//===--------------------------------------------------------------------===//
30
31/// CreateTempAlloca - This creates a alloca and inserts it into the entry
32/// block.
33llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
34                                                    const llvm::Twine &Name) {
35  if (!Builder.isNamePreserving())
36    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
37  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
38}
39
40void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
41                                     llvm::Value *Init) {
42  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
43  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
44  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
45}
46
47llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
48                                                const llvm::Twine &Name) {
49  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
50  // FIXME: Should we prefer the preferred type alignment here?
51  CharUnits Align = getContext().getTypeAlignInChars(Ty);
52  Alloc->setAlignment(Align.getQuantity());
53  return Alloc;
54}
55
56llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
57                                                 const llvm::Twine &Name) {
58  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
59  // FIXME: Should we prefer the preferred type alignment here?
60  CharUnits Align = getContext().getTypeAlignInChars(Ty);
61  Alloc->setAlignment(Align.getQuantity());
62  return Alloc;
63}
64
65/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
66/// expression and compare the result against zero, returning an Int1Ty value.
67llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
68  QualType BoolTy = getContext().BoolTy;
69  if (E->getType()->isMemberFunctionPointerType()) {
70    LValue LV = EmitAggExprToLValue(E);
71
72    // Get the pointer.
73    llvm::Value *FuncPtr = Builder.CreateStructGEP(LV.getAddress(), 0,
74                                                   "src.ptr");
75    FuncPtr = Builder.CreateLoad(FuncPtr);
76
77    llvm::Value *IsNotNull =
78      Builder.CreateICmpNE(FuncPtr,
79                            llvm::Constant::getNullValue(FuncPtr->getType()),
80                            "tobool");
81
82    return IsNotNull;
83  }
84  if (!E->getType()->isAnyComplexType())
85    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
86
87  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
88}
89
90/// EmitAnyExpr - Emit code to compute the specified expression which can have
91/// any type.  The result is returned as an RValue struct.  If this is an
92/// aggregate expression, the aggloc/agglocvolatile arguments indicate where the
93/// result should be returned.
94RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc,
95                                    bool IsAggLocVolatile, bool IgnoreResult,
96                                    bool IsInitializer) {
97  if (!hasAggregateLLVMType(E->getType()))
98    return RValue::get(EmitScalarExpr(E, IgnoreResult));
99  else if (E->getType()->isAnyComplexType())
100    return RValue::getComplex(EmitComplexExpr(E, false, false,
101                                              IgnoreResult, IgnoreResult));
102
103  EmitAggExpr(E, AggLoc, IsAggLocVolatile, IgnoreResult, IsInitializer);
104  return RValue::getAggregate(AggLoc, IsAggLocVolatile);
105}
106
107/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
108/// always be accessible even if no aggregate location is provided.
109RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E,
110                                          bool IsAggLocVolatile,
111                                          bool IsInitializer) {
112  llvm::Value *AggLoc = 0;
113
114  if (hasAggregateLLVMType(E->getType()) &&
115      !E->getType()->isAnyComplexType())
116    AggLoc = CreateMemTemp(E->getType(), "agg.tmp");
117  return EmitAnyExpr(E, AggLoc, IsAggLocVolatile, /*IgnoreResult=*/false,
118                     IsInitializer);
119}
120
121/// EmitAnyExprToMem - Evaluate an expression into a given memory
122/// location.
123void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
124                                       llvm::Value *Location,
125                                       bool IsLocationVolatile,
126                                       bool IsInit) {
127  if (E->getType()->isComplexType())
128    EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
129  else if (hasAggregateLLVMType(E->getType()))
130    EmitAggExpr(E, Location, IsLocationVolatile, /*Ignore*/ false, IsInit);
131  else {
132    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
133    LValue LV = LValue::MakeAddr(Location, MakeQualifiers(E->getType()));
134    EmitStoreThroughLValue(RV, LV, E->getType());
135  }
136}
137
138/// \brief An adjustment to be made to the temporary created when emitting a
139/// reference binding, which accesses a particular subobject of that temporary.
140struct SubobjectAdjustment {
141  enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
142
143  union {
144    struct {
145      const CastExpr *BasePath;
146      const CXXRecordDecl *DerivedClass;
147    } DerivedToBase;
148
149    struct {
150      FieldDecl *Field;
151      unsigned CVRQualifiers;
152    } Field;
153  };
154
155  SubobjectAdjustment(const CastExpr *BasePath,
156                      const CXXRecordDecl *DerivedClass)
157    : Kind(DerivedToBaseAdjustment)
158  {
159    DerivedToBase.BasePath = BasePath;
160    DerivedToBase.DerivedClass = DerivedClass;
161  }
162
163  SubobjectAdjustment(FieldDecl *Field, unsigned CVRQualifiers)
164    : Kind(FieldAdjustment)
165  {
166    this->Field.Field = Field;
167    this->Field.CVRQualifiers = CVRQualifiers;
168  }
169};
170
171static llvm::Value *
172CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
173                         const NamedDecl *InitializedDecl) {
174  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
175    if (VD->hasGlobalStorage()) {
176      llvm::SmallString<256> Name;
177      CGF.CGM.getMangleContext().mangleReferenceTemporary(VD, Name);
178
179      const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
180
181      // Create the reference temporary.
182      llvm::GlobalValue *RefTemp =
183        new llvm::GlobalVariable(CGF.CGM.getModule(),
184                                 RefTempTy, /*isConstant=*/false,
185                                 llvm::GlobalValue::InternalLinkage,
186                                 llvm::Constant::getNullValue(RefTempTy),
187                                 Name.str());
188      return RefTemp;
189    }
190  }
191
192  return CGF.CreateMemTemp(Type, "ref.tmp");
193}
194
195static llvm::Value *
196EmitExprForReferenceBinding(CodeGenFunction& CGF, const Expr* E,
197                            llvm::Value *&ReferenceTemporary,
198                            const CXXDestructorDecl *&ReferenceTemporaryDtor,
199                            const NamedDecl *InitializedDecl) {
200  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
201    E = DAE->getExpr();
202
203  if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
204    CodeGenFunction::RunCleanupsScope Scope(CGF);
205
206    return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
207                                       ReferenceTemporary,
208                                       ReferenceTemporaryDtor,
209                                       InitializedDecl);
210  }
211
212  RValue RV;
213  if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) {
214    // Emit the expression as an lvalue.
215    LValue LV = CGF.EmitLValue(E);
216
217    if (LV.isSimple())
218      return LV.getAddress();
219
220    // We have to load the lvalue.
221    RV = CGF.EmitLoadOfLValue(LV, E->getType());
222  } else {
223    QualType ResultTy = E->getType();
224
225    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
226    while (true) {
227      if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
228        E = PE->getSubExpr();
229        continue;
230      }
231
232      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
233        if ((CE->getCastKind() == CastExpr::CK_DerivedToBase ||
234             CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) &&
235            E->getType()->isRecordType()) {
236          E = CE->getSubExpr();
237          CXXRecordDecl *Derived
238            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
239          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
240          continue;
241        }
242
243        if (CE->getCastKind() == CastExpr::CK_NoOp) {
244          E = CE->getSubExpr();
245          continue;
246        }
247      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
248        if (ME->getBase()->isLvalue(CGF.getContext()) != Expr::LV_Valid &&
249            ME->getBase()->getType()->isRecordType()) {
250          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
251            E = ME->getBase();
252            Adjustments.push_back(SubobjectAdjustment(Field,
253                                              E->getType().getCVRQualifiers()));
254            continue;
255          }
256        }
257      }
258
259      // Nothing changed.
260      break;
261    }
262
263    // Create a reference temporary if necessary.
264    if (CGF.hasAggregateLLVMType(E->getType()) &&
265        !E->getType()->isAnyComplexType())
266      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
267                                                    InitializedDecl);
268
269    RV = CGF.EmitAnyExpr(E, ReferenceTemporary, /*IsAggLocVolatile=*/false,
270                         /*IgnoreResult=*/false, InitializedDecl);
271
272    if (InitializedDecl) {
273      // Get the destructor for the reference temporary.
274      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
275        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
276        if (!ClassDecl->hasTrivialDestructor())
277          ReferenceTemporaryDtor = ClassDecl->getDestructor();
278      }
279    }
280
281    // Check if need to perform derived-to-base casts and/or field accesses, to
282    // get from the temporary object we created (and, potentially, for which we
283    // extended the lifetime) to the subobject we're binding the reference to.
284    if (!Adjustments.empty()) {
285      llvm::Value *Object = RV.getAggregateAddr();
286      for (unsigned I = Adjustments.size(); I != 0; --I) {
287        SubobjectAdjustment &Adjustment = Adjustments[I-1];
288        switch (Adjustment.Kind) {
289        case SubobjectAdjustment::DerivedToBaseAdjustment:
290          Object =
291              CGF.GetAddressOfBaseClass(Object,
292                                        Adjustment.DerivedToBase.DerivedClass,
293                              Adjustment.DerivedToBase.BasePath->path_begin(),
294                              Adjustment.DerivedToBase.BasePath->path_end(),
295                                        /*NullCheckValue=*/false);
296          break;
297
298        case SubobjectAdjustment::FieldAdjustment: {
299          unsigned CVR = Adjustment.Field.CVRQualifiers;
300          LValue LV =
301            CGF.EmitLValueForField(Object, Adjustment.Field.Field, CVR);
302          if (LV.isSimple()) {
303            Object = LV.getAddress();
304            break;
305          }
306
307          // For non-simple lvalues, we actually have to create a copy of
308          // the object we're binding to.
309          QualType T = Adjustment.Field.Field->getType().getNonReferenceType()
310                                                        .getUnqualifiedType();
311          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
312          LValue TempLV = LValue::MakeAddr(Object,
313                                           Qualifiers::fromCVRMask(CVR));
314          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV, T), TempLV, T);
315          break;
316        }
317
318        }
319      }
320
321      const llvm::Type *ResultPtrTy = CGF.ConvertType(ResultTy)->getPointerTo();
322      return CGF.Builder.CreateBitCast(Object, ResultPtrTy, "temp");
323    }
324  }
325
326  if (RV.isAggregate())
327    return RV.getAggregateAddr();
328
329  // Create a temporary variable that we can bind the reference to.
330  ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
331                                                InitializedDecl);
332
333
334  unsigned Alignment =
335    CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
336  if (RV.isScalar())
337    CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
338                          /*Volatile=*/false, Alignment, E->getType());
339  else
340    CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
341                           /*Volatile=*/false);
342  return ReferenceTemporary;
343}
344
345RValue
346CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
347                                            const NamedDecl *InitializedDecl) {
348  llvm::Value *ReferenceTemporary = 0;
349  const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
350  llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
351                                                   ReferenceTemporaryDtor,
352                                                   InitializedDecl);
353
354  if (!ReferenceTemporaryDtor)
355    return RValue::get(Value);
356
357  // Make sure to call the destructor for the reference temporary.
358  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
359    if (VD->hasGlobalStorage()) {
360      llvm::Constant *DtorFn =
361        CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
362      CGF.EmitCXXGlobalDtorRegistration(DtorFn,
363                                      cast<llvm::Constant>(ReferenceTemporary));
364
365      return RValue::get(Value);
366    }
367  }
368
369  PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
370
371  return RValue::get(Value);
372}
373
374
375/// getAccessedFieldNo - Given an encoded value and a result number, return the
376/// input field number being accessed.
377unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
378                                             const llvm::Constant *Elts) {
379  if (isa<llvm::ConstantAggregateZero>(Elts))
380    return 0;
381
382  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
383}
384
385void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
386  if (!CatchUndefined)
387    return;
388
389  Address = Builder.CreateBitCast(Address, PtrToInt8Ty);
390
391  const llvm::Type *IntPtrT = IntPtrTy;
392  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
393  const llvm::IntegerType *Int1Ty = llvm::Type::getInt1Ty(VMContext);
394
395  // In time, people may want to control this and use a 1 here.
396  llvm::Value *Arg = llvm::ConstantInt::get(Int1Ty, 0);
397  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
398  llvm::BasicBlock *Cont = createBasicBlock();
399  llvm::BasicBlock *Check = createBasicBlock();
400  llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
401  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
402
403  EmitBlock(Check);
404  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
405                                        llvm::ConstantInt::get(IntPtrTy, Size)),
406                       Cont, getTrapBB());
407  EmitBlock(Cont);
408}
409
410
411CodeGenFunction::ComplexPairTy CodeGenFunction::
412EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
413                         bool isInc, bool isPre) {
414  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
415                                            LV.isVolatileQualified());
416
417  llvm::Value *NextVal;
418  if (isa<llvm::IntegerType>(InVal.first->getType())) {
419    uint64_t AmountVal = isInc ? 1 : -1;
420    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
421
422    // Add the inc/dec to the real part.
423    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
424  } else {
425    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
426    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
427    if (!isInc)
428      FVal.changeSign();
429    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
430
431    // Add the inc/dec to the real part.
432    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
433  }
434
435  ComplexPairTy IncVal(NextVal, InVal.second);
436
437  // Store the updated result through the lvalue.
438  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
439
440  // If this is a postinc, return the value read from memory, otherwise use the
441  // updated value.
442  return isPre ? IncVal : InVal;
443}
444
445
446//===----------------------------------------------------------------------===//
447//                         LValue Expression Emission
448//===----------------------------------------------------------------------===//
449
450RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
451  if (Ty->isVoidType())
452    return RValue::get(0);
453
454  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
455    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
456    llvm::Value *U = llvm::UndefValue::get(EltTy);
457    return RValue::getComplex(std::make_pair(U, U));
458  }
459
460  if (hasAggregateLLVMType(Ty)) {
461    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
462    return RValue::getAggregate(llvm::UndefValue::get(LTy));
463  }
464
465  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
466}
467
468RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
469                                              const char *Name) {
470  ErrorUnsupported(E, Name);
471  return GetUndefRValue(E->getType());
472}
473
474LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
475                                              const char *Name) {
476  ErrorUnsupported(E, Name);
477  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
478  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
479                          MakeQualifiers(E->getType()));
480}
481
482LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
483  LValue LV = EmitLValue(E);
484  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
485    EmitCheck(LV.getAddress(), getContext().getTypeSize(E->getType()) / 8);
486  return LV;
487}
488
489/// EmitLValue - Emit code to compute a designator that specifies the location
490/// of the expression.
491///
492/// This can return one of two things: a simple address or a bitfield reference.
493/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
494/// an LLVM pointer type.
495///
496/// If this returns a bitfield reference, nothing about the pointee type of the
497/// LLVM value is known: For example, it may not be a pointer to an integer.
498///
499/// If this returns a normal address, and if the lvalue's C type is fixed size,
500/// this method guarantees that the returned pointer type will point to an LLVM
501/// type of the same size of the lvalue's type.  If the lvalue has a variable
502/// length type, this is not possible.
503///
504LValue CodeGenFunction::EmitLValue(const Expr *E) {
505  switch (E->getStmtClass()) {
506  default: return EmitUnsupportedLValue(E, "l-value expression");
507
508  case Expr::ObjCSelectorExprClass:
509  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
510  case Expr::ObjCIsaExprClass:
511    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
512  case Expr::BinaryOperatorClass:
513    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
514  case Expr::CompoundAssignOperatorClass:
515    return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
516  case Expr::CallExprClass:
517  case Expr::CXXMemberCallExprClass:
518  case Expr::CXXOperatorCallExprClass:
519    return EmitCallExprLValue(cast<CallExpr>(E));
520  case Expr::VAArgExprClass:
521    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
522  case Expr::DeclRefExprClass:
523    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
524  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
525  case Expr::PredefinedExprClass:
526    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
527  case Expr::StringLiteralClass:
528    return EmitStringLiteralLValue(cast<StringLiteral>(E));
529  case Expr::ObjCEncodeExprClass:
530    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
531
532  case Expr::BlockDeclRefExprClass:
533    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
534
535  case Expr::CXXTemporaryObjectExprClass:
536  case Expr::CXXConstructExprClass:
537    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
538  case Expr::CXXBindTemporaryExprClass:
539    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
540  case Expr::CXXExprWithTemporariesClass:
541    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
542  case Expr::CXXScalarValueInitExprClass:
543    return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
544  case Expr::CXXDefaultArgExprClass:
545    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
546  case Expr::CXXTypeidExprClass:
547    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
548
549  case Expr::ObjCMessageExprClass:
550    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
551  case Expr::ObjCIvarRefExprClass:
552    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
553  case Expr::ObjCPropertyRefExprClass:
554    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
555  case Expr::ObjCImplicitSetterGetterRefExprClass:
556    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
557  case Expr::ObjCSuperExprClass:
558    return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
559
560  case Expr::StmtExprClass:
561    return EmitStmtExprLValue(cast<StmtExpr>(E));
562  case Expr::UnaryOperatorClass:
563    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
564  case Expr::ArraySubscriptExprClass:
565    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
566  case Expr::ExtVectorElementExprClass:
567    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
568  case Expr::MemberExprClass:
569    return EmitMemberExpr(cast<MemberExpr>(E));
570  case Expr::CompoundLiteralExprClass:
571    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
572  case Expr::ConditionalOperatorClass:
573    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
574  case Expr::ChooseExprClass:
575    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
576  case Expr::ImplicitCastExprClass:
577  case Expr::CStyleCastExprClass:
578  case Expr::CXXFunctionalCastExprClass:
579  case Expr::CXXStaticCastExprClass:
580  case Expr::CXXDynamicCastExprClass:
581  case Expr::CXXReinterpretCastExprClass:
582  case Expr::CXXConstCastExprClass:
583    return EmitCastLValue(cast<CastExpr>(E));
584  }
585}
586
587llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
588                                              unsigned Alignment, QualType Ty) {
589  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
590  if (Volatile)
591    Load->setVolatile(true);
592  if (Alignment)
593    Load->setAlignment(Alignment);
594
595  // Bool can have different representation in memory than in registers.
596  llvm::Value *V = Load;
597  if (Ty->isBooleanType())
598    if (V->getType() != llvm::Type::getInt1Ty(VMContext))
599      V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
600
601  return V;
602}
603
604void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
605                                        bool Volatile, unsigned Alignment,
606                                        QualType Ty) {
607
608  if (Ty->isBooleanType()) {
609    // Bool can have different representation in memory than in registers.
610    const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
611    Value = Builder.CreateIntCast(Value, DstPtr->getElementType(), false);
612  }
613
614  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
615  if (Alignment)
616    Store->setAlignment(Alignment);
617}
618
619/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
620/// method emits the address of the lvalue, then loads the result as an rvalue,
621/// returning the rvalue.
622RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
623  if (LV.isObjCWeak()) {
624    // load of a __weak object.
625    llvm::Value *AddrWeakObj = LV.getAddress();
626    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
627                                                             AddrWeakObj));
628  }
629
630  if (LV.isSimple()) {
631    llvm::Value *Ptr = LV.getAddress();
632    const llvm::Type *EltTy =
633      cast<llvm::PointerType>(Ptr->getType())->getElementType();
634
635    // Simple scalar l-value.
636    //
637    // FIXME: We shouldn't have to use isSingleValueType here.
638    if (EltTy->isSingleValueType())
639      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
640                                          LV.getAlignment(), ExprType));
641
642    assert(ExprType->isFunctionType() && "Unknown scalar value");
643    return RValue::get(Ptr);
644  }
645
646  if (LV.isVectorElt()) {
647    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
648                                          LV.isVolatileQualified(), "tmp");
649    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
650                                                    "vecext"));
651  }
652
653  // If this is a reference to a subset of the elements of a vector, either
654  // shuffle the input or extract/insert them as appropriate.
655  if (LV.isExtVectorElt())
656    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
657
658  if (LV.isBitField())
659    return EmitLoadOfBitfieldLValue(LV, ExprType);
660
661  if (LV.isPropertyRef())
662    return EmitLoadOfPropertyRefLValue(LV, ExprType);
663
664  assert(LV.isKVCRef() && "Unknown LValue type!");
665  return EmitLoadOfKVCRefLValue(LV, ExprType);
666}
667
668RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
669                                                 QualType ExprType) {
670  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
671
672  // Get the output type.
673  const llvm::Type *ResLTy = ConvertType(ExprType);
674  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
675
676  // Compute the result as an OR of all of the individual component accesses.
677  llvm::Value *Res = 0;
678  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
679    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
680
681    // Get the field pointer.
682    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
683
684    // Only offset by the field index if used, so that incoming values are not
685    // required to be structures.
686    if (AI.FieldIndex)
687      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
688
689    // Offset by the byte offset, if used.
690    if (AI.FieldByteOffset) {
691      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
692      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
693      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
694    }
695
696    // Cast to the access type.
697    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
698                                                    ExprType.getAddressSpace());
699    Ptr = Builder.CreateBitCast(Ptr, PTy);
700
701    // Perform the load.
702    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
703    if (AI.AccessAlignment)
704      Load->setAlignment(AI.AccessAlignment);
705
706    // Shift out unused low bits and mask out unused high bits.
707    llvm::Value *Val = Load;
708    if (AI.FieldBitStart)
709      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
710    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
711                                                            AI.TargetBitWidth),
712                            "bf.clear");
713
714    // Extend or truncate to the target size.
715    if (AI.AccessWidth < ResSizeInBits)
716      Val = Builder.CreateZExt(Val, ResLTy);
717    else if (AI.AccessWidth > ResSizeInBits)
718      Val = Builder.CreateTrunc(Val, ResLTy);
719
720    // Shift into place, and OR into the result.
721    if (AI.TargetBitOffset)
722      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
723    Res = Res ? Builder.CreateOr(Res, Val) : Val;
724  }
725
726  // If the bit-field is signed, perform the sign-extension.
727  //
728  // FIXME: This can easily be folded into the load of the high bits, which
729  // could also eliminate the mask of high bits in some situations.
730  if (Info.isSigned()) {
731    unsigned ExtraBits = ResSizeInBits - Info.getSize();
732    if (ExtraBits)
733      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
734                               ExtraBits, "bf.val.sext");
735  }
736
737  return RValue::get(Res);
738}
739
740RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
741                                                    QualType ExprType) {
742  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
743}
744
745RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
746                                               QualType ExprType) {
747  return EmitObjCPropertyGet(LV.getKVCRefExpr());
748}
749
750// If this is a reference to a subset of the elements of a vector, create an
751// appropriate shufflevector.
752RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
753                                                         QualType ExprType) {
754  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
755                                        LV.isVolatileQualified(), "tmp");
756
757  const llvm::Constant *Elts = LV.getExtVectorElts();
758
759  // If the result of the expression is a non-vector type, we must be extracting
760  // a single element.  Just codegen as an extractelement.
761  const VectorType *ExprVT = ExprType->getAs<VectorType>();
762  if (!ExprVT) {
763    unsigned InIdx = getAccessedFieldNo(0, Elts);
764    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
765    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
766  }
767
768  // Always use shuffle vector to try to retain the original program structure
769  unsigned NumResultElts = ExprVT->getNumElements();
770
771  llvm::SmallVector<llvm::Constant*, 4> Mask;
772  for (unsigned i = 0; i != NumResultElts; ++i) {
773    unsigned InIdx = getAccessedFieldNo(i, Elts);
774    Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx));
775  }
776
777  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
778  Vec = Builder.CreateShuffleVector(Vec,
779                                    llvm::UndefValue::get(Vec->getType()),
780                                    MaskV, "tmp");
781  return RValue::get(Vec);
782}
783
784
785
786/// EmitStoreThroughLValue - Store the specified rvalue into the specified
787/// lvalue, where both are guaranteed to the have the same type, and that type
788/// is 'Ty'.
789void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
790                                             QualType Ty) {
791  if (!Dst.isSimple()) {
792    if (Dst.isVectorElt()) {
793      // Read/modify/write the vector, inserting the new element.
794      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
795                                            Dst.isVolatileQualified(), "tmp");
796      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
797                                        Dst.getVectorIdx(), "vecins");
798      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
799      return;
800    }
801
802    // If this is an update of extended vector elements, insert them as
803    // appropriate.
804    if (Dst.isExtVectorElt())
805      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
806
807    if (Dst.isBitField())
808      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
809
810    if (Dst.isPropertyRef())
811      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
812
813    assert(Dst.isKVCRef() && "Unknown LValue type");
814    return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
815  }
816
817  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
818    // load of a __weak object.
819    llvm::Value *LvalueDst = Dst.getAddress();
820    llvm::Value *src = Src.getScalarVal();
821     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
822    return;
823  }
824
825  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
826    // load of a __strong object.
827    llvm::Value *LvalueDst = Dst.getAddress();
828    llvm::Value *src = Src.getScalarVal();
829    if (Dst.isObjCIvar()) {
830      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
831      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
832      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
833      llvm::Value *dst = RHS;
834      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
835      llvm::Value *LHS =
836        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
837      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
838      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
839                                              BytesBetween);
840    } else if (Dst.isGlobalObjCRef()) {
841      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
842                                                Dst.isThreadLocalRef());
843    }
844    else
845      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
846    return;
847  }
848
849  assert(Src.isScalar() && "Can't emit an agg store with this method");
850  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
851                    Dst.isVolatileQualified(), Dst.getAlignment(), Ty);
852}
853
854void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
855                                                     QualType Ty,
856                                                     llvm::Value **Result) {
857  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
858
859  // Get the output type.
860  const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
861  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
862
863  // Get the source value, truncated to the width of the bit-field.
864  llvm::Value *SrcVal = Src.getScalarVal();
865
866  if (Ty->isBooleanType())
867    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
868
869  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
870                                                                Info.getSize()),
871                             "bf.value");
872
873  // Return the new value of the bit-field, if requested.
874  if (Result) {
875    // Cast back to the proper type for result.
876    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
877    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
878                                                   "bf.reload.val");
879
880    // Sign extend if necessary.
881    if (Info.isSigned()) {
882      unsigned ExtraBits = ResSizeInBits - Info.getSize();
883      if (ExtraBits)
884        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
885                                       ExtraBits, "bf.reload.sext");
886    }
887
888    *Result = ReloadVal;
889  }
890
891  // Iterate over the components, writing each piece to memory.
892  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
893    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
894
895    // Get the field pointer.
896    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
897
898    // Only offset by the field index if used, so that incoming values are not
899    // required to be structures.
900    if (AI.FieldIndex)
901      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
902
903    // Offset by the byte offset, if used.
904    if (AI.FieldByteOffset) {
905      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
906      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
907      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
908    }
909
910    // Cast to the access type.
911    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
912                                                     Ty.getAddressSpace());
913    Ptr = Builder.CreateBitCast(Ptr, PTy);
914
915    // Extract the piece of the bit-field value to write in this access, limited
916    // to the values that are part of this access.
917    llvm::Value *Val = SrcVal;
918    if (AI.TargetBitOffset)
919      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
920    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
921                                                            AI.TargetBitWidth));
922
923    // Extend or truncate to the access size.
924    const llvm::Type *AccessLTy =
925      llvm::Type::getIntNTy(VMContext, AI.AccessWidth);
926    if (ResSizeInBits < AI.AccessWidth)
927      Val = Builder.CreateZExt(Val, AccessLTy);
928    else if (ResSizeInBits > AI.AccessWidth)
929      Val = Builder.CreateTrunc(Val, AccessLTy);
930
931    // Shift into the position in memory.
932    if (AI.FieldBitStart)
933      Val = Builder.CreateShl(Val, AI.FieldBitStart);
934
935    // If necessary, load and OR in bits that are outside of the bit-field.
936    if (AI.TargetBitWidth != AI.AccessWidth) {
937      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
938      if (AI.AccessAlignment)
939        Load->setAlignment(AI.AccessAlignment);
940
941      // Compute the mask for zeroing the bits that are part of the bit-field.
942      llvm::APInt InvMask =
943        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
944                                 AI.FieldBitStart + AI.TargetBitWidth);
945
946      // Apply the mask and OR in to the value to write.
947      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
948    }
949
950    // Write the value.
951    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
952                                                 Dst.isVolatileQualified());
953    if (AI.AccessAlignment)
954      Store->setAlignment(AI.AccessAlignment);
955  }
956}
957
958void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
959                                                        LValue Dst,
960                                                        QualType Ty) {
961  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
962}
963
964void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
965                                                   LValue Dst,
966                                                   QualType Ty) {
967  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
968}
969
970void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
971                                                               LValue Dst,
972                                                               QualType Ty) {
973  // This access turns into a read/modify/write of the vector.  Load the input
974  // value now.
975  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
976                                        Dst.isVolatileQualified(), "tmp");
977  const llvm::Constant *Elts = Dst.getExtVectorElts();
978
979  llvm::Value *SrcVal = Src.getScalarVal();
980
981  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
982    unsigned NumSrcElts = VTy->getNumElements();
983    unsigned NumDstElts =
984       cast<llvm::VectorType>(Vec->getType())->getNumElements();
985    if (NumDstElts == NumSrcElts) {
986      // Use shuffle vector is the src and destination are the same number of
987      // elements and restore the vector mask since it is on the side it will be
988      // stored.
989      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
990      for (unsigned i = 0; i != NumSrcElts; ++i) {
991        unsigned InIdx = getAccessedFieldNo(i, Elts);
992        Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
993      }
994
995      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
996      Vec = Builder.CreateShuffleVector(SrcVal,
997                                        llvm::UndefValue::get(Vec->getType()),
998                                        MaskV, "tmp");
999    } else if (NumDstElts > NumSrcElts) {
1000      // Extended the source vector to the same length and then shuffle it
1001      // into the destination.
1002      // FIXME: since we're shuffling with undef, can we just use the indices
1003      //        into that?  This could be simpler.
1004      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1005      unsigned i;
1006      for (i = 0; i != NumSrcElts; ++i)
1007        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1008      for (; i != NumDstElts; ++i)
1009        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1010      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
1011                                                        ExtMask.size());
1012      llvm::Value *ExtSrcVal =
1013        Builder.CreateShuffleVector(SrcVal,
1014                                    llvm::UndefValue::get(SrcVal->getType()),
1015                                    ExtMaskV, "tmp");
1016      // build identity
1017      llvm::SmallVector<llvm::Constant*, 4> Mask;
1018      for (unsigned i = 0; i != NumDstElts; ++i)
1019        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1020
1021      // modify when what gets shuffled in
1022      for (unsigned i = 0; i != NumSrcElts; ++i) {
1023        unsigned Idx = getAccessedFieldNo(i, Elts);
1024        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
1025      }
1026      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
1027      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
1028    } else {
1029      // We should never shorten the vector
1030      assert(0 && "unexpected shorten vector length");
1031    }
1032  } else {
1033    // If the Src is a scalar (not a vector) it must be updating one element.
1034    unsigned InIdx = getAccessedFieldNo(0, Elts);
1035    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
1036    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
1037  }
1038
1039  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
1040}
1041
1042// setObjCGCLValueClass - sets class of he lvalue for the purpose of
1043// generating write-barries API. It is currently a global, ivar,
1044// or neither.
1045static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1046                                 LValue &LV) {
1047  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
1048    return;
1049
1050  if (isa<ObjCIvarRefExpr>(E)) {
1051    LV.SetObjCIvar(LV, true);
1052    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
1053    LV.setBaseIvarExp(Exp->getBase());
1054    LV.SetObjCArray(LV, E->getType()->isArrayType());
1055    return;
1056  }
1057
1058  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
1059    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1060      if ((VD->isBlockVarDecl() && !VD->hasLocalStorage()) ||
1061          VD->isFileVarDecl()) {
1062        LV.SetGlobalObjCRef(LV, true);
1063        LV.SetThreadLocalRef(LV, VD->isThreadSpecified());
1064      }
1065    }
1066    LV.SetObjCArray(LV, E->getType()->isArrayType());
1067    return;
1068  }
1069
1070  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
1071    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1072    return;
1073  }
1074
1075  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
1076    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1077    if (LV.isObjCIvar()) {
1078      // If cast is to a structure pointer, follow gcc's behavior and make it
1079      // a non-ivar write-barrier.
1080      QualType ExpTy = E->getType();
1081      if (ExpTy->isPointerType())
1082        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1083      if (ExpTy->isRecordType())
1084        LV.SetObjCIvar(LV, false);
1085    }
1086    return;
1087  }
1088  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1089    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1090    return;
1091  }
1092
1093  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1094    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1095    return;
1096  }
1097
1098  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1099    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1100    if (LV.isObjCIvar() && !LV.isObjCArray())
1101      // Using array syntax to assigning to what an ivar points to is not
1102      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1103      LV.SetObjCIvar(LV, false);
1104    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1105      // Using array syntax to assigning to what global points to is not
1106      // same as assigning to the global itself. {id *G;} G[i] = 0;
1107      LV.SetGlobalObjCRef(LV, false);
1108    return;
1109  }
1110
1111  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1112    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1113    // We don't know if member is an 'ivar', but this flag is looked at
1114    // only in the context of LV.isObjCIvar().
1115    LV.SetObjCArray(LV, E->getType()->isArrayType());
1116    return;
1117  }
1118}
1119
1120static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1121                                      const Expr *E, const VarDecl *VD) {
1122  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1123         "Var decl must have external storage or be a file var decl!");
1124
1125  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1126  if (VD->getType()->isReferenceType())
1127    V = CGF.Builder.CreateLoad(V, "tmp");
1128  LValue LV = LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
1129  setObjCGCLValueClass(CGF.getContext(), E, LV);
1130  return LV;
1131}
1132
1133static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1134                                      const Expr *E, const FunctionDecl *FD) {
1135  llvm::Value* V = CGF.CGM.GetAddrOfFunction(FD);
1136  if (!FD->hasPrototype()) {
1137    if (const FunctionProtoType *Proto =
1138            FD->getType()->getAs<FunctionProtoType>()) {
1139      // Ugly case: for a K&R-style definition, the type of the definition
1140      // isn't the same as the type of a use.  Correct for this with a
1141      // bitcast.
1142      QualType NoProtoType =
1143          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1144      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1145      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1146    }
1147  }
1148  return LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
1149}
1150
1151LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1152  const NamedDecl *ND = E->getDecl();
1153
1154  if (ND->hasAttr<WeakRefAttr>()) {
1155    const ValueDecl* VD = cast<ValueDecl>(ND);
1156    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1157
1158    Qualifiers Quals = MakeQualifiers(E->getType());
1159    LValue LV = LValue::MakeAddr(Aliasee, Quals);
1160
1161    return LV;
1162  }
1163
1164  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1165
1166    // Check if this is a global variable.
1167    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1168      return EmitGlobalVarDeclLValue(*this, E, VD);
1169
1170    bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
1171
1172    llvm::Value *V = LocalDeclMap[VD];
1173    if (!V && getContext().getLangOptions().CPlusPlus &&
1174        VD->isStaticLocal())
1175      V = CGM.getStaticLocalDeclAddress(VD);
1176    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1177
1178    Qualifiers Quals = MakeQualifiers(E->getType());
1179    // local variables do not get their gc attribute set.
1180    // local static?
1181    if (NonGCable) Quals.removeObjCGCAttr();
1182
1183    if (VD->hasAttr<BlocksAttr>()) {
1184      V = Builder.CreateStructGEP(V, 1, "forwarding");
1185      V = Builder.CreateLoad(V);
1186      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
1187                                  VD->getNameAsString());
1188    }
1189    if (VD->getType()->isReferenceType())
1190      V = Builder.CreateLoad(V, "tmp");
1191    LValue LV = LValue::MakeAddr(V, Quals);
1192    LValue::SetObjCNonGC(LV, NonGCable);
1193    setObjCGCLValueClass(getContext(), E, LV);
1194    return LV;
1195  }
1196
1197  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1198    return EmitFunctionDeclLValue(*this, E, FD);
1199
1200  // FIXME: the qualifier check does not seem sufficient here
1201  if (E->getQualifier()) {
1202    const FieldDecl *FD = cast<FieldDecl>(ND);
1203    llvm::Value *V = CGM.EmitPointerToDataMember(FD);
1204
1205    return LValue::MakeAddr(V, MakeQualifiers(FD->getType()));
1206  }
1207
1208  assert(false && "Unhandled DeclRefExpr");
1209
1210  // an invalid LValue, but the assert will
1211  // ensure that this point is never reached.
1212  return LValue();
1213}
1214
1215LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1216  return LValue::MakeAddr(GetAddrOfBlockDecl(E), MakeQualifiers(E->getType()));
1217}
1218
1219LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1220  // __extension__ doesn't affect lvalue-ness.
1221  if (E->getOpcode() == UnaryOperator::Extension)
1222    return EmitLValue(E->getSubExpr());
1223
1224  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1225  switch (E->getOpcode()) {
1226  default: assert(0 && "Unknown unary operator lvalue!");
1227  case UnaryOperator::Deref: {
1228    QualType T = E->getSubExpr()->getType()->getPointeeType();
1229    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1230
1231    Qualifiers Quals = MakeQualifiers(T);
1232    Quals.setAddressSpace(ExprTy.getAddressSpace());
1233
1234    LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), Quals);
1235    // We should not generate __weak write barrier on indirect reference
1236    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1237    // But, we continue to generate __strong write barrier on indirect write
1238    // into a pointer to object.
1239    if (getContext().getLangOptions().ObjC1 &&
1240        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1241        LV.isObjCWeak())
1242      LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1243    return LV;
1244  }
1245  case UnaryOperator::Real:
1246  case UnaryOperator::Imag: {
1247    LValue LV = EmitLValue(E->getSubExpr());
1248    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
1249    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
1250                                                    Idx, "idx"),
1251                            MakeQualifiers(ExprTy));
1252  }
1253  case UnaryOperator::PreInc:
1254  case UnaryOperator::PreDec: {
1255    LValue LV = EmitLValue(E->getSubExpr());
1256    bool isInc = E->getOpcode() == UnaryOperator::PreInc;
1257
1258    if (E->getType()->isAnyComplexType())
1259      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1260    else
1261      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1262    return LV;
1263  }
1264  }
1265}
1266
1267LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1268  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E),
1269                          Qualifiers());
1270}
1271
1272LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1273  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1274                          Qualifiers());
1275}
1276
1277
1278LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
1279  std::string GlobalVarName;
1280
1281  switch (Type) {
1282  default: assert(0 && "Invalid type");
1283  case PredefinedExpr::Func:
1284    GlobalVarName = "__func__.";
1285    break;
1286  case PredefinedExpr::Function:
1287    GlobalVarName = "__FUNCTION__.";
1288    break;
1289  case PredefinedExpr::PrettyFunction:
1290    GlobalVarName = "__PRETTY_FUNCTION__.";
1291    break;
1292  }
1293
1294  llvm::StringRef FnName = CurFn->getName();
1295  if (FnName.startswith("\01"))
1296    FnName = FnName.substr(1);
1297  GlobalVarName += FnName;
1298
1299  const Decl *CurDecl = CurCodeDecl;
1300  if (CurDecl == 0)
1301    CurDecl = getContext().getTranslationUnitDecl();
1302
1303  std::string FunctionName =
1304    PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl);
1305
1306  llvm::Constant *C =
1307    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1308  return LValue::MakeAddr(C, Qualifiers());
1309}
1310
1311LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1312  switch (E->getIdentType()) {
1313  default:
1314    return EmitUnsupportedLValue(E, "predefined expression");
1315  case PredefinedExpr::Func:
1316  case PredefinedExpr::Function:
1317  case PredefinedExpr::PrettyFunction:
1318    return EmitPredefinedFunctionName(E->getIdentType());
1319  }
1320}
1321
1322llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1323  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1324
1325  // If we are not optimzing, don't collapse all calls to trap in the function
1326  // to the same call, that way, in the debugger they can see which operation
1327  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1328  // to just one per function to save on codesize.
1329  if (GCO.OptimizationLevel && TrapBB)
1330    return TrapBB;
1331
1332  llvm::BasicBlock *Cont = 0;
1333  if (HaveInsertPoint()) {
1334    Cont = createBasicBlock("cont");
1335    EmitBranch(Cont);
1336  }
1337  TrapBB = createBasicBlock("trap");
1338  EmitBlock(TrapBB);
1339
1340  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1341  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1342  TrapCall->setDoesNotReturn();
1343  TrapCall->setDoesNotThrow();
1344  Builder.CreateUnreachable();
1345
1346  if (Cont)
1347    EmitBlock(Cont);
1348  return TrapBB;
1349}
1350
1351/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1352/// array to pointer, return the array subexpression.
1353static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1354  // If this isn't just an array->pointer decay, bail out.
1355  const CastExpr *CE = dyn_cast<CastExpr>(E);
1356  if (CE == 0 || CE->getCastKind() != CastExpr::CK_ArrayToPointerDecay)
1357    return 0;
1358
1359  // If this is a decay from variable width array, bail out.
1360  const Expr *SubExpr = CE->getSubExpr();
1361  if (SubExpr->getType()->isVariableArrayType())
1362    return 0;
1363
1364  return SubExpr;
1365}
1366
1367LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1368  // The index must always be an integer, which is not an aggregate.  Emit it.
1369  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1370  QualType IdxTy  = E->getIdx()->getType();
1371  bool IdxSigned = IdxTy->isSignedIntegerType();
1372
1373  // If the base is a vector type, then we are forming a vector element lvalue
1374  // with this subscript.
1375  if (E->getBase()->getType()->isVectorType()) {
1376    // Emit the vector as an lvalue to get its address.
1377    LValue LHS = EmitLValue(E->getBase());
1378    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1379    Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vidx");
1380    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1381                                 E->getBase()->getType().getCVRQualifiers());
1382  }
1383
1384  // Extend or truncate the index type to 32 or 64-bits.
1385  if (!Idx->getType()->isIntegerTy(LLVMPointerWidth))
1386    Idx = Builder.CreateIntCast(Idx, IntPtrTy,
1387                                IdxSigned, "idxprom");
1388
1389  // FIXME: As llvm implements the object size checking, this can come out.
1390  if (CatchUndefined) {
1391    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1392      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1393        if (ICE->getCastKind() == CastExpr::CK_ArrayToPointerDecay) {
1394          if (const ConstantArrayType *CAT
1395              = getContext().getAsConstantArrayType(DRE->getType())) {
1396            llvm::APInt Size = CAT->getSize();
1397            llvm::BasicBlock *Cont = createBasicBlock("cont");
1398            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1399                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1400                                 Cont, getTrapBB());
1401            EmitBlock(Cont);
1402          }
1403        }
1404      }
1405    }
1406  }
1407
1408  // We know that the pointer points to a type of the correct size, unless the
1409  // size is a VLA or Objective-C interface.
1410  llvm::Value *Address = 0;
1411  if (const VariableArrayType *VAT =
1412        getContext().getAsVariableArrayType(E->getType())) {
1413    llvm::Value *VLASize = GetVLASize(VAT);
1414
1415    Idx = Builder.CreateMul(Idx, VLASize);
1416
1417    QualType BaseType = getContext().getBaseElementType(VAT);
1418
1419    CharUnits BaseTypeSize = getContext().getTypeSizeInChars(BaseType);
1420    Idx = Builder.CreateUDiv(Idx,
1421                             llvm::ConstantInt::get(Idx->getType(),
1422                                 BaseTypeSize.getQuantity()));
1423
1424    // The base must be a pointer, which is not an aggregate.  Emit it.
1425    llvm::Value *Base = EmitScalarExpr(E->getBase());
1426
1427    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1428  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1429    // Indexing over an interface, as in "NSString *P; P[4];"
1430    llvm::Value *InterfaceSize =
1431      llvm::ConstantInt::get(Idx->getType(),
1432          getContext().getTypeSizeInChars(OIT).getQuantity());
1433
1434    Idx = Builder.CreateMul(Idx, InterfaceSize);
1435
1436    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1437
1438    // The base must be a pointer, which is not an aggregate.  Emit it.
1439    llvm::Value *Base = EmitScalarExpr(E->getBase());
1440    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1441                                Idx, "arrayidx");
1442    Address = Builder.CreateBitCast(Address, Base->getType());
1443  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1444    // If this is A[i] where A is an array, the frontend will have decayed the
1445    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1446    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1447    // "gep x, i" here.  Emit one "gep A, 0, i".
1448    assert(Array->getType()->isArrayType() &&
1449           "Array to pointer decay must have array source type!");
1450    llvm::Value *ArrayPtr = EmitLValue(Array).getAddress();
1451    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1452    llvm::Value *Args[] = { Zero, Idx };
1453
1454    Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1455  } else {
1456    // The base must be a pointer, which is not an aggregate.  Emit it.
1457    llvm::Value *Base = EmitScalarExpr(E->getBase());
1458    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1459  }
1460
1461  QualType T = E->getBase()->getType()->getPointeeType();
1462  assert(!T.isNull() &&
1463         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1464
1465  Qualifiers Quals = MakeQualifiers(T);
1466  Quals.setAddressSpace(E->getBase()->getType().getAddressSpace());
1467
1468  LValue LV = LValue::MakeAddr(Address, Quals);
1469  if (getContext().getLangOptions().ObjC1 &&
1470      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1471    LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1472    setObjCGCLValueClass(getContext(), E, LV);
1473  }
1474  return LV;
1475}
1476
1477static
1478llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1479                                       llvm::SmallVector<unsigned, 4> &Elts) {
1480  llvm::SmallVector<llvm::Constant*, 4> CElts;
1481
1482  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1483  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1484    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1485
1486  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1487}
1488
1489LValue CodeGenFunction::
1490EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1491  // Emit the base vector as an l-value.
1492  LValue Base;
1493
1494  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1495  if (E->isArrow()) {
1496    // If it is a pointer to a vector, emit the address and form an lvalue with
1497    // it.
1498    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1499    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1500    Qualifiers Quals = MakeQualifiers(PT->getPointeeType());
1501    Quals.removeObjCGCAttr();
1502    Base = LValue::MakeAddr(Ptr, Quals);
1503  } else if (E->getBase()->isLvalue(getContext()) == Expr::LV_Valid) {
1504    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1505    // emit the base as an lvalue.
1506    assert(E->getBase()->getType()->isVectorType());
1507    Base = EmitLValue(E->getBase());
1508  } else {
1509    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1510    assert(E->getBase()->getType()->getAs<VectorType>() &&
1511           "Result must be a vector");
1512    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1513
1514    // Store the vector to memory (because LValue wants an address).
1515    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1516    Builder.CreateStore(Vec, VecMem);
1517    Base = LValue::MakeAddr(VecMem, Qualifiers());
1518  }
1519
1520  // Encode the element access list into a vector of unsigned indices.
1521  llvm::SmallVector<unsigned, 4> Indices;
1522  E->getEncodedElementAccess(Indices);
1523
1524  if (Base.isSimple()) {
1525    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1526    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1527                                    Base.getVRQualifiers());
1528  }
1529  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1530
1531  llvm::Constant *BaseElts = Base.getExtVectorElts();
1532  llvm::SmallVector<llvm::Constant *, 4> CElts;
1533
1534  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1535    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1536      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1537    else
1538      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1539  }
1540  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1541  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1542                                  Base.getVRQualifiers());
1543}
1544
1545LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1546  bool isNonGC = false;
1547  Expr *BaseExpr = E->getBase();
1548  llvm::Value *BaseValue = NULL;
1549  Qualifiers BaseQuals;
1550
1551  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1552  if (E->isArrow()) {
1553    BaseValue = EmitScalarExpr(BaseExpr);
1554    const PointerType *PTy =
1555      BaseExpr->getType()->getAs<PointerType>();
1556    BaseQuals = PTy->getPointeeType().getQualifiers();
1557  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1558             isa<ObjCImplicitSetterGetterRefExpr>(
1559               BaseExpr->IgnoreParens())) {
1560    RValue RV = EmitObjCPropertyGet(BaseExpr);
1561    BaseValue = RV.getAggregateAddr();
1562    BaseQuals = BaseExpr->getType().getQualifiers();
1563  } else {
1564    LValue BaseLV = EmitLValue(BaseExpr);
1565    if (BaseLV.isNonGC())
1566      isNonGC = true;
1567    // FIXME: this isn't right for bitfields.
1568    BaseValue = BaseLV.getAddress();
1569    QualType BaseTy = BaseExpr->getType();
1570    BaseQuals = BaseTy.getQualifiers();
1571  }
1572
1573  NamedDecl *ND = E->getMemberDecl();
1574  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1575    LValue LV = EmitLValueForField(BaseValue, Field,
1576                                   BaseQuals.getCVRQualifiers());
1577    LValue::SetObjCNonGC(LV, isNonGC);
1578    setObjCGCLValueClass(getContext(), E, LV);
1579    return LV;
1580  }
1581
1582  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1583    return EmitGlobalVarDeclLValue(*this, E, VD);
1584
1585  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1586    return EmitFunctionDeclLValue(*this, E, FD);
1587
1588  assert(false && "Unhandled member declaration!");
1589  return LValue();
1590}
1591
1592LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
1593                                              const FieldDecl* Field,
1594                                              unsigned CVRQualifiers) {
1595  const CGRecordLayout &RL =
1596    CGM.getTypes().getCGRecordLayout(Field->getParent());
1597  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1598  return LValue::MakeBitfield(BaseValue, Info,
1599                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1600}
1601
1602/// EmitLValueForAnonRecordField - Given that the field is a member of
1603/// an anonymous struct or union buried inside a record, and given
1604/// that the base value is a pointer to the enclosing record, derive
1605/// an lvalue for the ultimate field.
1606LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1607                                                     const FieldDecl *Field,
1608                                                     unsigned CVRQualifiers) {
1609  llvm::SmallVector<const FieldDecl *, 8> Path;
1610  Path.push_back(Field);
1611
1612  while (Field->getParent()->isAnonymousStructOrUnion()) {
1613    const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
1614    if (!isa<FieldDecl>(VD)) break;
1615    Field = cast<FieldDecl>(VD);
1616    Path.push_back(Field);
1617  }
1618
1619  llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
1620    I = Path.rbegin(), E = Path.rend();
1621  while (true) {
1622    LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
1623    if (++I == E) return LV;
1624
1625    assert(LV.isSimple());
1626    BaseValue = LV.getAddress();
1627    CVRQualifiers |= LV.getVRQualifiers();
1628  }
1629}
1630
1631LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
1632                                           const FieldDecl* Field,
1633                                           unsigned CVRQualifiers) {
1634  if (Field->isBitField())
1635    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1636
1637  const CGRecordLayout &RL =
1638    CGM.getTypes().getCGRecordLayout(Field->getParent());
1639  unsigned idx = RL.getLLVMFieldNo(Field);
1640  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1641
1642  // Match union field type.
1643  if (Field->getParent()->isUnion()) {
1644    const llvm::Type *FieldTy =
1645      CGM.getTypes().ConvertTypeForMem(Field->getType());
1646    const llvm::PointerType * BaseTy =
1647      cast<llvm::PointerType>(BaseValue->getType());
1648    unsigned AS = BaseTy->getAddressSpace();
1649    V = Builder.CreateBitCast(V,
1650                              llvm::PointerType::get(FieldTy, AS),
1651                              "tmp");
1652  }
1653  if (Field->getType()->isReferenceType())
1654    V = Builder.CreateLoad(V, "tmp");
1655
1656  Qualifiers Quals = MakeQualifiers(Field->getType());
1657  Quals.addCVRQualifiers(CVRQualifiers);
1658  // __weak attribute on a field is ignored.
1659  if (Quals.getObjCGCAttr() == Qualifiers::Weak)
1660    Quals.removeObjCGCAttr();
1661
1662  return LValue::MakeAddr(V, Quals);
1663}
1664
1665LValue
1666CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value* BaseValue,
1667                                                  const FieldDecl* Field,
1668                                                  unsigned CVRQualifiers) {
1669  QualType FieldType = Field->getType();
1670
1671  if (!FieldType->isReferenceType())
1672    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1673
1674  const CGRecordLayout &RL =
1675    CGM.getTypes().getCGRecordLayout(Field->getParent());
1676  unsigned idx = RL.getLLVMFieldNo(Field);
1677  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1678
1679  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1680
1681  return LValue::MakeAddr(V, MakeQualifiers(FieldType));
1682}
1683
1684LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
1685  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1686  const Expr* InitExpr = E->getInitializer();
1687  LValue Result = LValue::MakeAddr(DeclPtr, MakeQualifiers(E->getType()));
1688
1689  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false);
1690
1691  return Result;
1692}
1693
1694LValue
1695CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
1696  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1697    if (int Cond = ConstantFoldsToSimpleInteger(E->getCond())) {
1698      Expr *Live = Cond == 1 ? E->getLHS() : E->getRHS();
1699      if (Live)
1700        return EmitLValue(Live);
1701    }
1702
1703    if (!E->getLHS())
1704      return EmitUnsupportedLValue(E, "conditional operator with missing LHS");
1705
1706    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1707    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1708    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1709
1710    EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1711
1712    // Any temporaries created here are conditional.
1713    BeginConditionalBranch();
1714    EmitBlock(LHSBlock);
1715    LValue LHS = EmitLValue(E->getLHS());
1716    EndConditionalBranch();
1717
1718    if (!LHS.isSimple())
1719      return EmitUnsupportedLValue(E, "conditional operator");
1720
1721    // FIXME: We shouldn't need an alloca for this.
1722    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1723    Builder.CreateStore(LHS.getAddress(), Temp);
1724    EmitBranch(ContBlock);
1725
1726    // Any temporaries created here are conditional.
1727    BeginConditionalBranch();
1728    EmitBlock(RHSBlock);
1729    LValue RHS = EmitLValue(E->getRHS());
1730    EndConditionalBranch();
1731    if (!RHS.isSimple())
1732      return EmitUnsupportedLValue(E, "conditional operator");
1733
1734    Builder.CreateStore(RHS.getAddress(), Temp);
1735    EmitBranch(ContBlock);
1736
1737    EmitBlock(ContBlock);
1738
1739    Temp = Builder.CreateLoad(Temp, "lv");
1740    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1741  }
1742
1743  // ?: here should be an aggregate.
1744  assert((hasAggregateLLVMType(E->getType()) &&
1745          !E->getType()->isAnyComplexType()) &&
1746         "Unexpected conditional operator!");
1747
1748  return EmitAggExprToLValue(E);
1749}
1750
1751/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1752/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1753/// otherwise if a cast is needed by the code generator in an lvalue context,
1754/// then it must mean that we need the address of an aggregate in order to
1755/// access one of its fields.  This can happen for all the reasons that casts
1756/// are permitted with aggregate result, including noop aggregate casts, and
1757/// cast from scalar to union.
1758LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1759  switch (E->getCastKind()) {
1760  case CastExpr::CK_ToVoid:
1761    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1762
1763  case CastExpr::CK_NoOp:
1764    if (E->getSubExpr()->Classify(getContext()).getKind()
1765                                          != Expr::Classification::CL_PRValue) {
1766      LValue LV = EmitLValue(E->getSubExpr());
1767      if (LV.isPropertyRef()) {
1768        QualType QT = E->getSubExpr()->getType();
1769        RValue RV = EmitLoadOfPropertyRefLValue(LV, QT);
1770        assert(!RV.isScalar() && "EmitCastLValue-scalar cast of property ref");
1771        llvm::Value *V = RV.getAggregateAddr();
1772        return LValue::MakeAddr(V, MakeQualifiers(QT));
1773      }
1774      return LV;
1775    }
1776    // Fall through to synthesize a temporary.
1777
1778  case CastExpr::CK_Unknown:
1779  case CastExpr::CK_BitCast:
1780  case CastExpr::CK_ArrayToPointerDecay:
1781  case CastExpr::CK_FunctionToPointerDecay:
1782  case CastExpr::CK_NullToMemberPointer:
1783  case CastExpr::CK_IntegralToPointer:
1784  case CastExpr::CK_PointerToIntegral:
1785  case CastExpr::CK_VectorSplat:
1786  case CastExpr::CK_IntegralCast:
1787  case CastExpr::CK_IntegralToFloating:
1788  case CastExpr::CK_FloatingToIntegral:
1789  case CastExpr::CK_FloatingCast:
1790  case CastExpr::CK_DerivedToBaseMemberPointer:
1791  case CastExpr::CK_BaseToDerivedMemberPointer:
1792  case CastExpr::CK_MemberPointerToBoolean:
1793  case CastExpr::CK_AnyPointerToBlockPointerCast: {
1794    // These casts only produce lvalues when we're binding a reference to a
1795    // temporary realized from a (converted) pure rvalue. Emit the expression
1796    // as a value, copy it into a temporary, and return an lvalue referring to
1797    // that temporary.
1798    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
1799    EmitAnyExprToMem(E, V, false, false);
1800    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1801  }
1802
1803  case CastExpr::CK_Dynamic: {
1804    LValue LV = EmitLValue(E->getSubExpr());
1805    llvm::Value *V = LV.getAddress();
1806    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1807    return LValue::MakeAddr(EmitDynamicCast(V, DCE),
1808                            MakeQualifiers(E->getType()));
1809  }
1810
1811  case CastExpr::CK_ConstructorConversion:
1812  case CastExpr::CK_UserDefinedConversion:
1813  case CastExpr::CK_AnyPointerToObjCPointerCast:
1814    return EmitLValue(E->getSubExpr());
1815
1816  case CastExpr::CK_UncheckedDerivedToBase:
1817  case CastExpr::CK_DerivedToBase: {
1818    const RecordType *DerivedClassTy =
1819      E->getSubExpr()->getType()->getAs<RecordType>();
1820    CXXRecordDecl *DerivedClassDecl =
1821      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1822
1823    LValue LV = EmitLValue(E->getSubExpr());
1824    llvm::Value *This;
1825    if (LV.isPropertyRef()) {
1826      RValue RV = EmitLoadOfPropertyRefLValue(LV, E->getSubExpr()->getType());
1827      assert (!RV.isScalar() && "EmitCastLValue");
1828      This = RV.getAggregateAddr();
1829    }
1830    else
1831      This = LV.getAddress();
1832
1833    // Perform the derived-to-base conversion
1834    llvm::Value *Base =
1835      GetAddressOfBaseClass(This, DerivedClassDecl,
1836                            E->path_begin(), E->path_end(),
1837                            /*NullCheckValue=*/false);
1838
1839    return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
1840  }
1841  case CastExpr::CK_ToUnion:
1842    return EmitAggExprToLValue(E);
1843  case CastExpr::CK_BaseToDerived: {
1844    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1845    CXXRecordDecl *DerivedClassDecl =
1846      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1847
1848    LValue LV = EmitLValue(E->getSubExpr());
1849
1850    // Perform the base-to-derived conversion
1851    llvm::Value *Derived =
1852      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1853                               E->path_begin(), E->path_end(),
1854                               /*NullCheckValue=*/false);
1855
1856    return LValue::MakeAddr(Derived, MakeQualifiers(E->getType()));
1857  }
1858  case CastExpr::CK_LValueBitCast: {
1859    // This must be a reinterpret_cast (or c-style equivalent).
1860    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1861
1862    LValue LV = EmitLValue(E->getSubExpr());
1863    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1864                                           ConvertType(CE->getTypeAsWritten()));
1865    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1866  }
1867  case CastExpr::CK_ObjCObjectLValueCast: {
1868    LValue LV = EmitLValue(E->getSubExpr());
1869    QualType ToType = getContext().getLValueReferenceType(E->getType());
1870    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1871                                           ConvertType(ToType));
1872    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1873  }
1874  }
1875
1876  llvm_unreachable("Unhandled lvalue cast kind?");
1877}
1878
1879LValue CodeGenFunction::EmitNullInitializationLValue(
1880                                              const CXXScalarValueInitExpr *E) {
1881  QualType Ty = E->getType();
1882  LValue LV = LValue::MakeAddr(CreateMemTemp(Ty), MakeQualifiers(Ty));
1883  EmitNullInitialization(LV.getAddress(), Ty);
1884  return LV;
1885}
1886
1887//===--------------------------------------------------------------------===//
1888//                             Expression Emission
1889//===--------------------------------------------------------------------===//
1890
1891
1892RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
1893                                     ReturnValueSlot ReturnValue) {
1894  // Builtins never have block type.
1895  if (E->getCallee()->getType()->isBlockPointerType())
1896    return EmitBlockCallExpr(E, ReturnValue);
1897
1898  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1899    return EmitCXXMemberCallExpr(CE, ReturnValue);
1900
1901  const Decl *TargetDecl = 0;
1902  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1903    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1904      TargetDecl = DRE->getDecl();
1905      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1906        if (unsigned builtinID = FD->getBuiltinID())
1907          return EmitBuiltinExpr(FD, builtinID, E);
1908    }
1909  }
1910
1911  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1912    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1913      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
1914
1915  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1916    // C++ [expr.pseudo]p1:
1917    //   The result shall only be used as the operand for the function call
1918    //   operator (), and the result of such a call has type void. The only
1919    //   effect is the evaluation of the postfix-expression before the dot or
1920    //   arrow.
1921    EmitScalarExpr(E->getCallee());
1922    return RValue::get(0);
1923  }
1924
1925  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1926  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
1927                  E->arg_begin(), E->arg_end(), TargetDecl);
1928}
1929
1930LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1931  // Comma expressions just emit their LHS then their RHS as an l-value.
1932  if (E->getOpcode() == BinaryOperator::Comma) {
1933    EmitAnyExpr(E->getLHS());
1934    EnsureInsertPoint();
1935    return EmitLValue(E->getRHS());
1936  }
1937
1938  if (E->getOpcode() == BinaryOperator::PtrMemD ||
1939      E->getOpcode() == BinaryOperator::PtrMemI)
1940    return EmitPointerToDataMemberBinaryExpr(E);
1941
1942  // Can only get l-value for binary operator expressions which are a
1943  // simple assignment of aggregate type.
1944  if (E->getOpcode() != BinaryOperator::Assign)
1945    return EmitUnsupportedLValue(E, "binary l-value expression");
1946
1947  if (!hasAggregateLLVMType(E->getType())) {
1948    // Emit the LHS as an l-value.
1949    LValue LV = EmitLValue(E->getLHS());
1950    // Store the value through the l-value.
1951    EmitStoreThroughLValue(EmitAnyExpr(E->getRHS()), LV, E->getType());
1952    return LV;
1953  }
1954
1955  return EmitAggExprToLValue(E);
1956}
1957
1958LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
1959  RValue RV = EmitCallExpr(E);
1960
1961  if (!RV.isScalar())
1962    return LValue::MakeAddr(RV.getAggregateAddr(),MakeQualifiers(E->getType()));
1963
1964  assert(E->getCallReturnType()->isReferenceType() &&
1965         "Can't have a scalar return unless the return type is a "
1966         "reference type!");
1967
1968  return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
1969}
1970
1971LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
1972  // FIXME: This shouldn't require another copy.
1973  return EmitAggExprToLValue(E);
1974}
1975
1976LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
1977  llvm::Value *Temp = CreateMemTemp(E->getType(), "tmp");
1978  EmitCXXConstructExpr(Temp, E);
1979  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1980}
1981
1982LValue
1983CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
1984  llvm::Value *Temp = EmitCXXTypeidExpr(E);
1985  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1986}
1987
1988LValue
1989CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
1990  LValue LV = EmitLValue(E->getSubExpr());
1991  EmitCXXTemporary(E->getTemporary(), LV.getAddress());
1992  return LV;
1993}
1994
1995LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
1996  RValue RV = EmitObjCMessageExpr(E);
1997
1998  if (!RV.isScalar())
1999    return LValue::MakeAddr(RV.getAggregateAddr(),
2000                            MakeQualifiers(E->getType()));
2001
2002  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2003         "Can't have a scalar return unless the return type is a "
2004         "reference type!");
2005
2006  return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
2007}
2008
2009LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2010  llvm::Value *V =
2011    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2012  return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
2013}
2014
2015llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2016                                             const ObjCIvarDecl *Ivar) {
2017  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2018}
2019
2020LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2021                                          llvm::Value *BaseValue,
2022                                          const ObjCIvarDecl *Ivar,
2023                                          unsigned CVRQualifiers) {
2024  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2025                                                   Ivar, CVRQualifiers);
2026}
2027
2028LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2029  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2030  llvm::Value *BaseValue = 0;
2031  const Expr *BaseExpr = E->getBase();
2032  Qualifiers BaseQuals;
2033  QualType ObjectTy;
2034  if (E->isArrow()) {
2035    BaseValue = EmitScalarExpr(BaseExpr);
2036    ObjectTy = BaseExpr->getType()->getPointeeType();
2037    BaseQuals = ObjectTy.getQualifiers();
2038  } else {
2039    LValue BaseLV = EmitLValue(BaseExpr);
2040    // FIXME: this isn't right for bitfields.
2041    BaseValue = BaseLV.getAddress();
2042    ObjectTy = BaseExpr->getType();
2043    BaseQuals = ObjectTy.getQualifiers();
2044  }
2045
2046  LValue LV =
2047    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2048                      BaseQuals.getCVRQualifiers());
2049  setObjCGCLValueClass(getContext(), E, LV);
2050  return LV;
2051}
2052
2053LValue
2054CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
2055  // This is a special l-value that just issues sends when we load or store
2056  // through it.
2057  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
2058}
2059
2060LValue CodeGenFunction::EmitObjCKVCRefLValue(
2061                                const ObjCImplicitSetterGetterRefExpr *E) {
2062  // This is a special l-value that just issues sends when we load or store
2063  // through it.
2064  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
2065}
2066
2067LValue CodeGenFunction::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
2068  return EmitUnsupportedLValue(E, "use of super");
2069}
2070
2071LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2072  // Can only get l-value for message expression returning aggregate type
2073  RValue RV = EmitAnyExprToTemp(E);
2074  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
2075}
2076
2077RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2078                                 ReturnValueSlot ReturnValue,
2079                                 CallExpr::const_arg_iterator ArgBeg,
2080                                 CallExpr::const_arg_iterator ArgEnd,
2081                                 const Decl *TargetDecl) {
2082  // Get the actual function type. The callee type will always be a pointer to
2083  // function type or a block pointer type.
2084  assert(CalleeType->isFunctionPointerType() &&
2085         "Call must have function pointer type!");
2086
2087  CalleeType = getContext().getCanonicalType(CalleeType);
2088
2089  const FunctionType *FnType
2090    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2091  QualType ResultType = FnType->getResultType();
2092
2093  CallArgList Args;
2094  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2095
2096  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2097                  Callee, ReturnValue, Args, TargetDecl);
2098}
2099
2100LValue CodeGenFunction::
2101EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2102  llvm::Value *BaseV;
2103  if (E->getOpcode() == BinaryOperator::PtrMemI)
2104    BaseV = EmitScalarExpr(E->getLHS());
2105  else
2106    BaseV = EmitLValue(E->getLHS()).getAddress();
2107  const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
2108  BaseV = Builder.CreateBitCast(BaseV, i8Ty);
2109  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2110  llvm::Value *AddV = Builder.CreateInBoundsGEP(BaseV, OffsetV, "add.ptr");
2111
2112  QualType Ty = E->getRHS()->getType();
2113  Ty = Ty->getAs<MemberPointerType>()->getPointeeType();
2114
2115  const llvm::Type *PType = ConvertType(getContext().getPointerType(Ty));
2116  AddV = Builder.CreateBitCast(AddV, PType);
2117  return LValue::MakeAddr(AddV, MakeQualifiers(Ty));
2118}
2119
2120