CGExpr.cpp revision daa8e4e888758d55a7a759dd4a91b83921cef222 
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 "CGRecordLayout.h"
19#include "CGObjCRuntime.h"
20#include "clang/AST/ASTContext.h"
21#include "clang/AST/DeclObjC.h"
22#include "llvm/Intrinsics.h"
23#include "clang/Frontend/CodeGenOptions.h"
24#include "llvm/Target/TargetData.h"
25using namespace clang;
26using namespace CodeGen;
27
28//===--------------------------------------------------------------------===//
29//                        Miscellaneous Helper Methods
30//===--------------------------------------------------------------------===//
31
32/// CreateTempAlloca - This creates a alloca and inserts it into the entry
33/// block.
34llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
35                                                    const llvm::Twine &Name) {
36  if (!Builder.isNamePreserving())
37    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
38  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
39}
40
41void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
42                                     llvm::Value *Init) {
43  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
44  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
45  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
46}
47
48llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
49                                                const llvm::Twine &Name) {
50  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
51  // FIXME: Should we prefer the preferred type alignment here?
52  CharUnits Align = getContext().getTypeAlignInChars(Ty);
53  Alloc->setAlignment(Align.getQuantity());
54  return Alloc;
55}
56
57llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
58                                                 const llvm::Twine &Name) {
59  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
60  // FIXME: Should we prefer the preferred type alignment here?
61  CharUnits Align = getContext().getTypeAlignInChars(Ty);
62  Alloc->setAlignment(Align.getQuantity());
63  return Alloc;
64}
65
66/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
67/// expression and compare the result against zero, returning an Int1Ty value.
68llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
69  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
70    llvm::Value *MemPtr = EmitScalarExpr(E);
71    return CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT);
72  }
73
74  QualType BoolTy = getContext().BoolTy;
75  if (!E->getType()->isAnyComplexType())
76    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
77
78  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
79}
80
81/// EmitAnyExpr - Emit code to compute the specified expression which
82/// can have any type.  The result is returned as an RValue struct.
83/// If this is an aggregate expression, AggSlot indicates where the
84/// result should be returned.
85RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot,
86                                    bool IgnoreResult) {
87  if (!hasAggregateLLVMType(E->getType()))
88    return RValue::get(EmitScalarExpr(E, IgnoreResult));
89  else if (E->getType()->isAnyComplexType())
90    return RValue::getComplex(EmitComplexExpr(E, false, false,
91                                              IgnoreResult, IgnoreResult));
92
93  EmitAggExpr(E, AggSlot, IgnoreResult);
94  return AggSlot.asRValue();
95}
96
97/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
98/// always be accessible even if no aggregate location is provided.
99RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
100  AggValueSlot AggSlot = AggValueSlot::ignored();
101
102  if (hasAggregateLLVMType(E->getType()) &&
103      !E->getType()->isAnyComplexType())
104    AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
105  return EmitAnyExpr(E, AggSlot);
106}
107
108/// EmitAnyExprToMem - Evaluate an expression into a given memory
109/// location.
110void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
111                                       llvm::Value *Location,
112                                       bool IsLocationVolatile,
113                                       bool IsInit) {
114  if (E->getType()->isComplexType())
115    EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
116  else if (hasAggregateLLVMType(E->getType()))
117    EmitAggExpr(E, AggValueSlot::forAddr(Location, IsLocationVolatile, IsInit));
118  else {
119    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
120    LValue LV = MakeAddrLValue(Location, E->getType());
121    EmitStoreThroughLValue(RV, LV, E->getType());
122  }
123}
124
125/// \brief An adjustment to be made to the temporary created when emitting a
126/// reference binding, which accesses a particular subobject of that temporary.
127struct SubobjectAdjustment {
128  enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
129
130  union {
131    struct {
132      const CastExpr *BasePath;
133      const CXXRecordDecl *DerivedClass;
134    } DerivedToBase;
135
136    FieldDecl *Field;
137  };
138
139  SubobjectAdjustment(const CastExpr *BasePath,
140                      const CXXRecordDecl *DerivedClass)
141    : Kind(DerivedToBaseAdjustment)
142  {
143    DerivedToBase.BasePath = BasePath;
144    DerivedToBase.DerivedClass = DerivedClass;
145  }
146
147  SubobjectAdjustment(FieldDecl *Field)
148    : Kind(FieldAdjustment)
149  {
150    this->Field = Field;
151  }
152};
153
154static llvm::Value *
155CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
156                         const NamedDecl *InitializedDecl) {
157  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
158    if (VD->hasGlobalStorage()) {
159      llvm::SmallString<256> Name;
160      CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Name);
161
162      const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
163
164      // Create the reference temporary.
165      llvm::GlobalValue *RefTemp =
166        new llvm::GlobalVariable(CGF.CGM.getModule(),
167                                 RefTempTy, /*isConstant=*/false,
168                                 llvm::GlobalValue::InternalLinkage,
169                                 llvm::Constant::getNullValue(RefTempTy),
170                                 Name.str());
171      return RefTemp;
172    }
173  }
174
175  return CGF.CreateMemTemp(Type, "ref.tmp");
176}
177
178static llvm::Value *
179EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
180                            llvm::Value *&ReferenceTemporary,
181                            const CXXDestructorDecl *&ReferenceTemporaryDtor,
182                            const NamedDecl *InitializedDecl) {
183  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
184    E = DAE->getExpr();
185
186  if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
187    CodeGenFunction::RunCleanupsScope Scope(CGF);
188
189    return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
190                                       ReferenceTemporary,
191                                       ReferenceTemporaryDtor,
192                                       InitializedDecl);
193  }
194
195  RValue RV;
196  if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) {
197    // Emit the expression as an lvalue.
198    LValue LV = CGF.EmitLValue(E);
199    if (LV.isPropertyRef() || LV.isKVCRef()) {
200      QualType QT = E->getType();
201      RValue RV =
202        LV.isPropertyRef() ? CGF.EmitLoadOfPropertyRefLValue(LV, QT)
203                           : CGF.EmitLoadOfKVCRefLValue(LV, QT);
204      assert(RV.isScalar() && "EmitExprForReferenceBinding");
205      return RV.getScalarVal();
206    }
207
208    if (LV.isSimple())
209      return LV.getAddress();
210
211    // We have to load the lvalue.
212    RV = CGF.EmitLoadOfLValue(LV, E->getType());
213  } else {
214    QualType ResultTy = E->getType();
215
216    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
217    while (true) {
218      if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
219        E = PE->getSubExpr();
220        continue;
221      }
222
223      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
224        if ((CE->getCastKind() == CK_DerivedToBase ||
225             CE->getCastKind() == CK_UncheckedDerivedToBase) &&
226            E->getType()->isRecordType()) {
227          E = CE->getSubExpr();
228          CXXRecordDecl *Derived
229            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
230          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
231          continue;
232        }
233
234        if (CE->getCastKind() == CK_NoOp) {
235          E = CE->getSubExpr();
236          continue;
237        }
238      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
239        if (ME->getBase()->isLvalue(CGF.getContext()) != Expr::LV_Valid &&
240            ME->getBase()->getType()->isRecordType()) {
241          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
242            E = ME->getBase();
243            Adjustments.push_back(SubobjectAdjustment(Field));
244            continue;
245          }
246        }
247      }
248
249      // Nothing changed.
250      break;
251    }
252
253    // Create a reference temporary if necessary.
254    AggValueSlot AggSlot = AggValueSlot::ignored();
255    if (CGF.hasAggregateLLVMType(E->getType()) &&
256        !E->getType()->isAnyComplexType()) {
257      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
258                                                    InitializedDecl);
259      AggSlot = AggValueSlot::forAddr(ReferenceTemporary, false,
260                                      InitializedDecl != 0);
261    }
262
263    RV = CGF.EmitAnyExpr(E, AggSlot);
264
265    if (InitializedDecl) {
266      // Get the destructor for the reference temporary.
267      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
268        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
269        if (!ClassDecl->hasTrivialDestructor())
270          ReferenceTemporaryDtor = ClassDecl->getDestructor();
271      }
272    }
273
274    // Check if need to perform derived-to-base casts and/or field accesses, to
275    // get from the temporary object we created (and, potentially, for which we
276    // extended the lifetime) to the subobject we're binding the reference to.
277    if (!Adjustments.empty()) {
278      llvm::Value *Object = RV.getAggregateAddr();
279      for (unsigned I = Adjustments.size(); I != 0; --I) {
280        SubobjectAdjustment &Adjustment = Adjustments[I-1];
281        switch (Adjustment.Kind) {
282        case SubobjectAdjustment::DerivedToBaseAdjustment:
283          Object =
284              CGF.GetAddressOfBaseClass(Object,
285                                        Adjustment.DerivedToBase.DerivedClass,
286                              Adjustment.DerivedToBase.BasePath->path_begin(),
287                              Adjustment.DerivedToBase.BasePath->path_end(),
288                                        /*NullCheckValue=*/false);
289          break;
290
291        case SubobjectAdjustment::FieldAdjustment: {
292          LValue LV =
293            CGF.EmitLValueForField(Object, Adjustment.Field, 0);
294          if (LV.isSimple()) {
295            Object = LV.getAddress();
296            break;
297          }
298
299          // For non-simple lvalues, we actually have to create a copy of
300          // the object we're binding to.
301          QualType T = Adjustment.Field->getType().getNonReferenceType()
302                                                  .getUnqualifiedType();
303          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
304          LValue TempLV = CGF.MakeAddrLValue(Object,
305                                             Adjustment.Field->getType());
306          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV, T), TempLV, T);
307          break;
308        }
309
310        }
311      }
312
313      const llvm::Type *ResultPtrTy = CGF.ConvertType(ResultTy)->getPointerTo();
314      return CGF.Builder.CreateBitCast(Object, ResultPtrTy, "temp");
315    }
316  }
317
318  if (RV.isAggregate())
319    return RV.getAggregateAddr();
320
321  // Create a temporary variable that we can bind the reference to.
322  ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
323                                                InitializedDecl);
324
325
326  unsigned Alignment =
327    CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
328  if (RV.isScalar())
329    CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
330                          /*Volatile=*/false, Alignment, E->getType());
331  else
332    CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
333                           /*Volatile=*/false);
334  return ReferenceTemporary;
335}
336
337RValue
338CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E,
339                                            const NamedDecl *InitializedDecl) {
340  llvm::Value *ReferenceTemporary = 0;
341  const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
342  llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
343                                                   ReferenceTemporaryDtor,
344                                                   InitializedDecl);
345  if (!ReferenceTemporaryDtor)
346    return RValue::get(Value);
347
348  // Make sure to call the destructor for the reference temporary.
349  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
350    if (VD->hasGlobalStorage()) {
351      llvm::Constant *DtorFn =
352        CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
353      CGF.EmitCXXGlobalDtorRegistration(DtorFn,
354                                      cast<llvm::Constant>(ReferenceTemporary));
355
356      return RValue::get(Value);
357    }
358  }
359
360  PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
361
362  return RValue::get(Value);
363}
364
365
366/// getAccessedFieldNo - Given an encoded value and a result number, return the
367/// input field number being accessed.
368unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
369                                             const llvm::Constant *Elts) {
370  if (isa<llvm::ConstantAggregateZero>(Elts))
371    return 0;
372
373  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
374}
375
376void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
377  if (!CatchUndefined)
378    return;
379
380  Address = Builder.CreateBitCast(Address, PtrToInt8Ty);
381
382  const llvm::Type *IntPtrT = IntPtrTy;
383  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
384  const llvm::IntegerType *Int1Ty = llvm::Type::getInt1Ty(VMContext);
385
386  // In time, people may want to control this and use a 1 here.
387  llvm::Value *Arg = llvm::ConstantInt::get(Int1Ty, 0);
388  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
389  llvm::BasicBlock *Cont = createBasicBlock();
390  llvm::BasicBlock *Check = createBasicBlock();
391  llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
392  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
393
394  EmitBlock(Check);
395  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
396                                        llvm::ConstantInt::get(IntPtrTy, Size)),
397                       Cont, getTrapBB());
398  EmitBlock(Cont);
399}
400
401
402CodeGenFunction::ComplexPairTy CodeGenFunction::
403EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
404                         bool isInc, bool isPre) {
405  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
406                                            LV.isVolatileQualified());
407
408  llvm::Value *NextVal;
409  if (isa<llvm::IntegerType>(InVal.first->getType())) {
410    uint64_t AmountVal = isInc ? 1 : -1;
411    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
412
413    // Add the inc/dec to the real part.
414    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
415  } else {
416    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
417    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
418    if (!isInc)
419      FVal.changeSign();
420    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
421
422    // Add the inc/dec to the real part.
423    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
424  }
425
426  ComplexPairTy IncVal(NextVal, InVal.second);
427
428  // Store the updated result through the lvalue.
429  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
430
431  // If this is a postinc, return the value read from memory, otherwise use the
432  // updated value.
433  return isPre ? IncVal : InVal;
434}
435
436
437//===----------------------------------------------------------------------===//
438//                         LValue Expression Emission
439//===----------------------------------------------------------------------===//
440
441RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
442  if (Ty->isVoidType())
443    return RValue::get(0);
444
445  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
446    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
447    llvm::Value *U = llvm::UndefValue::get(EltTy);
448    return RValue::getComplex(std::make_pair(U, U));
449  }
450
451  // If this is a use of an undefined aggregate type, the aggregate must have an
452  // identifiable address.  Just because the contents of the value are undefined
453  // doesn't mean that the address can't be taken and compared.
454  if (hasAggregateLLVMType(Ty)) {
455    llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
456    return RValue::getAggregate(DestPtr);
457  }
458
459  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
460}
461
462RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
463                                              const char *Name) {
464  ErrorUnsupported(E, Name);
465  return GetUndefRValue(E->getType());
466}
467
468LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
469                                              const char *Name) {
470  ErrorUnsupported(E, Name);
471  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
472  return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType());
473}
474
475LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
476  LValue LV = EmitLValue(E);
477  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
478    EmitCheck(LV.getAddress(), getContext().getTypeSize(E->getType()) / 8);
479  return LV;
480}
481
482/// EmitLValue - Emit code to compute a designator that specifies the location
483/// of the expression.
484///
485/// This can return one of two things: a simple address or a bitfield reference.
486/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
487/// an LLVM pointer type.
488///
489/// If this returns a bitfield reference, nothing about the pointee type of the
490/// LLVM value is known: For example, it may not be a pointer to an integer.
491///
492/// If this returns a normal address, and if the lvalue's C type is fixed size,
493/// this method guarantees that the returned pointer type will point to an LLVM
494/// type of the same size of the lvalue's type.  If the lvalue has a variable
495/// length type, this is not possible.
496///
497LValue CodeGenFunction::EmitLValue(const Expr *E) {
498  llvm::DenseMap<const Expr *, LValue>::iterator I =
499                                      CGF.ConditionalSaveLValueExprs.find(E);
500  if (I != CGF.ConditionalSaveLValueExprs.end())
501    return I->second;
502
503  switch (E->getStmtClass()) {
504  default: return EmitUnsupportedLValue(E, "l-value expression");
505
506  case Expr::ObjCSelectorExprClass:
507  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
508  case Expr::ObjCIsaExprClass:
509    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
510  case Expr::BinaryOperatorClass:
511    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
512  case Expr::CompoundAssignOperatorClass:
513    return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
514  case Expr::CallExprClass:
515  case Expr::CXXMemberCallExprClass:
516  case Expr::CXXOperatorCallExprClass:
517    return EmitCallExprLValue(cast<CallExpr>(E));
518  case Expr::VAArgExprClass:
519    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
520  case Expr::DeclRefExprClass:
521    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
522  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
523  case Expr::PredefinedExprClass:
524    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
525  case Expr::StringLiteralClass:
526    return EmitStringLiteralLValue(cast<StringLiteral>(E));
527  case Expr::ObjCEncodeExprClass:
528    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
529
530  case Expr::BlockDeclRefExprClass:
531    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
532
533  case Expr::CXXTemporaryObjectExprClass:
534  case Expr::CXXConstructExprClass:
535    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
536  case Expr::CXXBindTemporaryExprClass:
537    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
538  case Expr::CXXExprWithTemporariesClass:
539    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
540  case Expr::CXXScalarValueInitExprClass:
541    return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
542  case Expr::CXXDefaultArgExprClass:
543    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
544  case Expr::CXXTypeidExprClass:
545    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
546
547  case Expr::ObjCMessageExprClass:
548    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
549  case Expr::ObjCIvarRefExprClass:
550    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
551  case Expr::ObjCPropertyRefExprClass:
552    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
553  case Expr::ObjCImplicitSetterGetterRefExprClass:
554    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
555  case Expr::StmtExprClass:
556    return EmitStmtExprLValue(cast<StmtExpr>(E));
557  case Expr::UnaryOperatorClass:
558    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
559  case Expr::ArraySubscriptExprClass:
560    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
561  case Expr::ExtVectorElementExprClass:
562    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
563  case Expr::MemberExprClass:
564    return EmitMemberExpr(cast<MemberExpr>(E));
565  case Expr::CompoundLiteralExprClass:
566    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
567  case Expr::ConditionalOperatorClass:
568    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
569  case Expr::ChooseExprClass:
570    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
571  case Expr::ImplicitCastExprClass:
572  case Expr::CStyleCastExprClass:
573  case Expr::CXXFunctionalCastExprClass:
574  case Expr::CXXStaticCastExprClass:
575  case Expr::CXXDynamicCastExprClass:
576  case Expr::CXXReinterpretCastExprClass:
577  case Expr::CXXConstCastExprClass:
578    return EmitCastLValue(cast<CastExpr>(E));
579  }
580}
581
582llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
583                                              unsigned Alignment, QualType Ty,
584                                              llvm::MDNode *TBAAInfo) {
585  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
586  if (Volatile)
587    Load->setVolatile(true);
588  if (Alignment)
589    Load->setAlignment(Alignment);
590  if (TBAAInfo)
591    CGM.DecorateInstruction(Load, TBAAInfo);
592
593  return EmitFromMemory(Load, Ty);
594}
595
596static bool isBooleanUnderlyingType(QualType Ty) {
597  if (const EnumType *ET = dyn_cast<EnumType>(Ty))
598    return ET->getDecl()->getIntegerType()->isBooleanType();
599  return false;
600}
601
602llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
603  // Bool has a different representation in memory than in registers.
604  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
605    // This should really always be an i1, but sometimes it's already
606    // an i8, and it's awkward to track those cases down.
607    if (Value->getType()->isIntegerTy(1))
608      return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool");
609    assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8");
610  }
611
612  return Value;
613}
614
615llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
616  // Bool has a different representation in memory than in registers.
617  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
618    assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8");
619    return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
620  }
621
622  return Value;
623}
624
625void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
626                                        bool Volatile, unsigned Alignment,
627                                        QualType Ty,
628                                        llvm::MDNode *TBAAInfo) {
629  Value = EmitToMemory(Value, Ty);
630  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
631  if (Alignment)
632    Store->setAlignment(Alignment);
633  if (TBAAInfo)
634    CGM.DecorateInstruction(Store, TBAAInfo);
635}
636
637/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
638/// method emits the address of the lvalue, then loads the result as an rvalue,
639/// returning the rvalue.
640RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
641  if (LV.isObjCWeak()) {
642    // load of a __weak object.
643    llvm::Value *AddrWeakObj = LV.getAddress();
644    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
645                                                             AddrWeakObj));
646  }
647
648  if (LV.isSimple()) {
649    llvm::Value *Ptr = LV.getAddress();
650
651    // Functions are l-values that don't require loading.
652    if (ExprType->isFunctionType())
653      return RValue::get(Ptr);
654
655    // Everything needs a load.
656    return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
657                                        LV.getAlignment(), ExprType,
658                                        LV.getTBAAInfo()));
659
660  }
661
662  if (LV.isVectorElt()) {
663    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
664                                          LV.isVolatileQualified(), "tmp");
665    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
666                                                    "vecext"));
667  }
668
669  // If this is a reference to a subset of the elements of a vector, either
670  // shuffle the input or extract/insert them as appropriate.
671  if (LV.isExtVectorElt())
672    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
673
674  if (LV.isBitField())
675    return EmitLoadOfBitfieldLValue(LV, ExprType);
676
677  if (LV.isPropertyRef())
678    return EmitLoadOfPropertyRefLValue(LV, ExprType);
679
680  assert(LV.isKVCRef() && "Unknown LValue type!");
681  return EmitLoadOfKVCRefLValue(LV, ExprType);
682}
683
684RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
685                                                 QualType ExprType) {
686  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
687
688  // Get the output type.
689  const llvm::Type *ResLTy = ConvertType(ExprType);
690  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
691
692  // Compute the result as an OR of all of the individual component accesses.
693  llvm::Value *Res = 0;
694  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
695    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
696
697    // Get the field pointer.
698    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
699
700    // Only offset by the field index if used, so that incoming values are not
701    // required to be structures.
702    if (AI.FieldIndex)
703      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
704
705    // Offset by the byte offset, if used.
706    if (AI.FieldByteOffset) {
707      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
708      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
709      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
710    }
711
712    // Cast to the access type.
713    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
714                                                    ExprType.getAddressSpace());
715    Ptr = Builder.CreateBitCast(Ptr, PTy);
716
717    // Perform the load.
718    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
719    if (AI.AccessAlignment)
720      Load->setAlignment(AI.AccessAlignment);
721
722    // Shift out unused low bits and mask out unused high bits.
723    llvm::Value *Val = Load;
724    if (AI.FieldBitStart)
725      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
726    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
727                                                            AI.TargetBitWidth),
728                            "bf.clear");
729
730    // Extend or truncate to the target size.
731    if (AI.AccessWidth < ResSizeInBits)
732      Val = Builder.CreateZExt(Val, ResLTy);
733    else if (AI.AccessWidth > ResSizeInBits)
734      Val = Builder.CreateTrunc(Val, ResLTy);
735
736    // Shift into place, and OR into the result.
737    if (AI.TargetBitOffset)
738      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
739    Res = Res ? Builder.CreateOr(Res, Val) : Val;
740  }
741
742  // If the bit-field is signed, perform the sign-extension.
743  //
744  // FIXME: This can easily be folded into the load of the high bits, which
745  // could also eliminate the mask of high bits in some situations.
746  if (Info.isSigned()) {
747    unsigned ExtraBits = ResSizeInBits - Info.getSize();
748    if (ExtraBits)
749      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
750                               ExtraBits, "bf.val.sext");
751  }
752
753  return RValue::get(Res);
754}
755
756RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
757                                                    QualType ExprType) {
758  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
759}
760
761RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
762                                               QualType ExprType) {
763  return EmitObjCPropertyGet(LV.getKVCRefExpr());
764}
765
766// If this is a reference to a subset of the elements of a vector, create an
767// appropriate shufflevector.
768RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
769                                                         QualType ExprType) {
770  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
771                                        LV.isVolatileQualified(), "tmp");
772
773  const llvm::Constant *Elts = LV.getExtVectorElts();
774
775  // If the result of the expression is a non-vector type, we must be extracting
776  // a single element.  Just codegen as an extractelement.
777  const VectorType *ExprVT = ExprType->getAs<VectorType>();
778  if (!ExprVT) {
779    unsigned InIdx = getAccessedFieldNo(0, Elts);
780    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
781    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
782  }
783
784  // Always use shuffle vector to try to retain the original program structure
785  unsigned NumResultElts = ExprVT->getNumElements();
786
787  llvm::SmallVector<llvm::Constant*, 4> Mask;
788  for (unsigned i = 0; i != NumResultElts; ++i) {
789    unsigned InIdx = getAccessedFieldNo(i, Elts);
790    Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx));
791  }
792
793  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
794  Vec = Builder.CreateShuffleVector(Vec,
795                                    llvm::UndefValue::get(Vec->getType()),
796                                    MaskV, "tmp");
797  return RValue::get(Vec);
798}
799
800
801
802/// EmitStoreThroughLValue - Store the specified rvalue into the specified
803/// lvalue, where both are guaranteed to the have the same type, and that type
804/// is 'Ty'.
805void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
806                                             QualType Ty) {
807  if (!Dst.isSimple()) {
808    if (Dst.isVectorElt()) {
809      // Read/modify/write the vector, inserting the new element.
810      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
811                                            Dst.isVolatileQualified(), "tmp");
812      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
813                                        Dst.getVectorIdx(), "vecins");
814      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
815      return;
816    }
817
818    // If this is an update of extended vector elements, insert them as
819    // appropriate.
820    if (Dst.isExtVectorElt())
821      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
822
823    if (Dst.isBitField())
824      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
825
826    if (Dst.isPropertyRef())
827      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
828
829    assert(Dst.isKVCRef() && "Unknown LValue type");
830    return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
831  }
832
833  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
834    // load of a __weak object.
835    llvm::Value *LvalueDst = Dst.getAddress();
836    llvm::Value *src = Src.getScalarVal();
837     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
838    return;
839  }
840
841  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
842    // load of a __strong object.
843    llvm::Value *LvalueDst = Dst.getAddress();
844    llvm::Value *src = Src.getScalarVal();
845    if (Dst.isObjCIvar()) {
846      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
847      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
848      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
849      llvm::Value *dst = RHS;
850      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
851      llvm::Value *LHS =
852        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
853      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
854      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
855                                              BytesBetween);
856    } else if (Dst.isGlobalObjCRef()) {
857      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
858                                                Dst.isThreadLocalRef());
859    }
860    else
861      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
862    return;
863  }
864
865  assert(Src.isScalar() && "Can't emit an agg store with this method");
866  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
867                    Dst.isVolatileQualified(), Dst.getAlignment(), Ty,
868                    Dst.getTBAAInfo());
869}
870
871void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
872                                                     QualType Ty,
873                                                     llvm::Value **Result) {
874  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
875
876  // Get the output type.
877  const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
878  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
879
880  // Get the source value, truncated to the width of the bit-field.
881  llvm::Value *SrcVal = Src.getScalarVal();
882
883  if (Ty->isBooleanType())
884    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
885
886  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
887                                                                Info.getSize()),
888                             "bf.value");
889
890  // Return the new value of the bit-field, if requested.
891  if (Result) {
892    // Cast back to the proper type for result.
893    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
894    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
895                                                   "bf.reload.val");
896
897    // Sign extend if necessary.
898    if (Info.isSigned()) {
899      unsigned ExtraBits = ResSizeInBits - Info.getSize();
900      if (ExtraBits)
901        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
902                                       ExtraBits, "bf.reload.sext");
903    }
904
905    *Result = ReloadVal;
906  }
907
908  // Iterate over the components, writing each piece to memory.
909  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
910    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
911
912    // Get the field pointer.
913    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
914
915    // Only offset by the field index if used, so that incoming values are not
916    // required to be structures.
917    if (AI.FieldIndex)
918      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
919
920    // Offset by the byte offset, if used.
921    if (AI.FieldByteOffset) {
922      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
923      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
924      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
925    }
926
927    // Cast to the access type.
928    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
929                                                     Ty.getAddressSpace());
930    Ptr = Builder.CreateBitCast(Ptr, PTy);
931
932    // Extract the piece of the bit-field value to write in this access, limited
933    // to the values that are part of this access.
934    llvm::Value *Val = SrcVal;
935    if (AI.TargetBitOffset)
936      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
937    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
938                                                            AI.TargetBitWidth));
939
940    // Extend or truncate to the access size.
941    const llvm::Type *AccessLTy =
942      llvm::Type::getIntNTy(VMContext, AI.AccessWidth);
943    if (ResSizeInBits < AI.AccessWidth)
944      Val = Builder.CreateZExt(Val, AccessLTy);
945    else if (ResSizeInBits > AI.AccessWidth)
946      Val = Builder.CreateTrunc(Val, AccessLTy);
947
948    // Shift into the position in memory.
949    if (AI.FieldBitStart)
950      Val = Builder.CreateShl(Val, AI.FieldBitStart);
951
952    // If necessary, load and OR in bits that are outside of the bit-field.
953    if (AI.TargetBitWidth != AI.AccessWidth) {
954      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
955      if (AI.AccessAlignment)
956        Load->setAlignment(AI.AccessAlignment);
957
958      // Compute the mask for zeroing the bits that are part of the bit-field.
959      llvm::APInt InvMask =
960        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
961                                 AI.FieldBitStart + AI.TargetBitWidth);
962
963      // Apply the mask and OR in to the value to write.
964      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
965    }
966
967    // Write the value.
968    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
969                                                 Dst.isVolatileQualified());
970    if (AI.AccessAlignment)
971      Store->setAlignment(AI.AccessAlignment);
972  }
973}
974
975void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
976                                                        LValue Dst,
977                                                        QualType Ty) {
978  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
979}
980
981void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
982                                                   LValue Dst,
983                                                   QualType Ty) {
984  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
985}
986
987void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
988                                                               LValue Dst,
989                                                               QualType Ty) {
990  // This access turns into a read/modify/write of the vector.  Load the input
991  // value now.
992  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
993                                        Dst.isVolatileQualified(), "tmp");
994  const llvm::Constant *Elts = Dst.getExtVectorElts();
995
996  llvm::Value *SrcVal = Src.getScalarVal();
997
998  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
999    unsigned NumSrcElts = VTy->getNumElements();
1000    unsigned NumDstElts =
1001       cast<llvm::VectorType>(Vec->getType())->getNumElements();
1002    if (NumDstElts == NumSrcElts) {
1003      // Use shuffle vector is the src and destination are the same number of
1004      // elements and restore the vector mask since it is on the side it will be
1005      // stored.
1006      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1007      for (unsigned i = 0; i != NumSrcElts; ++i) {
1008        unsigned InIdx = getAccessedFieldNo(i, Elts);
1009        Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
1010      }
1011
1012      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
1013      Vec = Builder.CreateShuffleVector(SrcVal,
1014                                        llvm::UndefValue::get(Vec->getType()),
1015                                        MaskV, "tmp");
1016    } else if (NumDstElts > NumSrcElts) {
1017      // Extended the source vector to the same length and then shuffle it
1018      // into the destination.
1019      // FIXME: since we're shuffling with undef, can we just use the indices
1020      //        into that?  This could be simpler.
1021      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1022      unsigned i;
1023      for (i = 0; i != NumSrcElts; ++i)
1024        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1025      for (; i != NumDstElts; ++i)
1026        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1027      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
1028                                                        ExtMask.size());
1029      llvm::Value *ExtSrcVal =
1030        Builder.CreateShuffleVector(SrcVal,
1031                                    llvm::UndefValue::get(SrcVal->getType()),
1032                                    ExtMaskV, "tmp");
1033      // build identity
1034      llvm::SmallVector<llvm::Constant*, 4> Mask;
1035      for (unsigned i = 0; i != NumDstElts; ++i)
1036        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1037
1038      // modify when what gets shuffled in
1039      for (unsigned i = 0; i != NumSrcElts; ++i) {
1040        unsigned Idx = getAccessedFieldNo(i, Elts);
1041        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
1042      }
1043      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
1044      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
1045    } else {
1046      // We should never shorten the vector
1047      assert(0 && "unexpected shorten vector length");
1048    }
1049  } else {
1050    // If the Src is a scalar (not a vector) it must be updating one element.
1051    unsigned InIdx = getAccessedFieldNo(0, Elts);
1052    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
1053    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
1054  }
1055
1056  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
1057}
1058
1059// setObjCGCLValueClass - sets class of he lvalue for the purpose of
1060// generating write-barries API. It is currently a global, ivar,
1061// or neither.
1062static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1063                                 LValue &LV) {
1064  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
1065    return;
1066
1067  if (isa<ObjCIvarRefExpr>(E)) {
1068    LV.setObjCIvar(true);
1069    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
1070    LV.setBaseIvarExp(Exp->getBase());
1071    LV.setObjCArray(E->getType()->isArrayType());
1072    return;
1073  }
1074
1075  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
1076    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1077      if (VD->hasGlobalStorage()) {
1078        LV.setGlobalObjCRef(true);
1079        LV.setThreadLocalRef(VD->isThreadSpecified());
1080      }
1081    }
1082    LV.setObjCArray(E->getType()->isArrayType());
1083    return;
1084  }
1085
1086  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
1087    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1088    return;
1089  }
1090
1091  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
1092    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1093    if (LV.isObjCIvar()) {
1094      // If cast is to a structure pointer, follow gcc's behavior and make it
1095      // a non-ivar write-barrier.
1096      QualType ExpTy = E->getType();
1097      if (ExpTy->isPointerType())
1098        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1099      if (ExpTy->isRecordType())
1100        LV.setObjCIvar(false);
1101    }
1102    return;
1103  }
1104  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1105    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1106    return;
1107  }
1108
1109  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1110    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1111    return;
1112  }
1113
1114  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1115    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1116    if (LV.isObjCIvar() && !LV.isObjCArray())
1117      // Using array syntax to assigning to what an ivar points to is not
1118      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1119      LV.setObjCIvar(false);
1120    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1121      // Using array syntax to assigning to what global points to is not
1122      // same as assigning to the global itself. {id *G;} G[i] = 0;
1123      LV.setGlobalObjCRef(false);
1124    return;
1125  }
1126
1127  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1128    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1129    // We don't know if member is an 'ivar', but this flag is looked at
1130    // only in the context of LV.isObjCIvar().
1131    LV.setObjCArray(E->getType()->isArrayType());
1132    return;
1133  }
1134}
1135
1136static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1137                                      const Expr *E, const VarDecl *VD) {
1138  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1139         "Var decl must have external storage or be a file var decl!");
1140
1141  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1142  if (VD->getType()->isReferenceType())
1143    V = CGF.Builder.CreateLoad(V, "tmp");
1144  unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity();
1145  LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment);
1146  setObjCGCLValueClass(CGF.getContext(), E, LV);
1147  return LV;
1148}
1149
1150static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1151                                      const Expr *E, const FunctionDecl *FD) {
1152  llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
1153  if (!FD->hasPrototype()) {
1154    if (const FunctionProtoType *Proto =
1155            FD->getType()->getAs<FunctionProtoType>()) {
1156      // Ugly case: for a K&R-style definition, the type of the definition
1157      // isn't the same as the type of a use.  Correct for this with a
1158      // bitcast.
1159      QualType NoProtoType =
1160          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1161      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1162      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1163    }
1164  }
1165  unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity();
1166  return CGF.MakeAddrLValue(V, E->getType(), Alignment);
1167}
1168
1169LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1170  const NamedDecl *ND = E->getDecl();
1171  unsigned Alignment = CGF.getContext().getDeclAlign(ND).getQuantity();
1172
1173  if (ND->hasAttr<WeakRefAttr>()) {
1174    const ValueDecl *VD = cast<ValueDecl>(ND);
1175    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1176    return MakeAddrLValue(Aliasee, E->getType(), Alignment);
1177  }
1178
1179  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1180
1181    // Check if this is a global variable.
1182    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1183      return EmitGlobalVarDeclLValue(*this, E, VD);
1184
1185    bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
1186
1187    llvm::Value *V = LocalDeclMap[VD];
1188    if (!V && VD->isStaticLocal())
1189      V = CGM.getStaticLocalDeclAddress(VD);
1190    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1191
1192    if (VD->hasAttr<BlocksAttr>()) {
1193      V = Builder.CreateStructGEP(V, 1, "forwarding");
1194      V = Builder.CreateLoad(V);
1195      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
1196                                  VD->getNameAsString());
1197    }
1198    if (VD->getType()->isReferenceType())
1199      V = Builder.CreateLoad(V, "tmp");
1200
1201    LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
1202    if (NonGCable) {
1203      LV.getQuals().removeObjCGCAttr();
1204      LV.setNonGC(true);
1205    }
1206    setObjCGCLValueClass(getContext(), E, LV);
1207    return LV;
1208  }
1209
1210  // If we're emitting an instance method as an independent lvalue,
1211  // we're actually emitting a member pointer.
1212  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1213    if (MD->isInstance()) {
1214      llvm::Value *V = CGM.getCXXABI().EmitMemberPointer(MD);
1215      return MakeAddrLValue(V, MD->getType(), Alignment);
1216    }
1217  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1218    return EmitFunctionDeclLValue(*this, E, FD);
1219
1220  // If we're emitting a field as an independent lvalue, we're
1221  // actually emitting a member pointer.
1222  if (const FieldDecl *FD = dyn_cast<FieldDecl>(ND)) {
1223    llvm::Value *V = CGM.getCXXABI().EmitMemberPointer(FD);
1224    return MakeAddrLValue(V, FD->getType(), Alignment);
1225  }
1226
1227  assert(false && "Unhandled DeclRefExpr");
1228
1229  // an invalid LValue, but the assert will
1230  // ensure that this point is never reached.
1231  return LValue();
1232}
1233
1234LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1235  unsigned Alignment =
1236    CGF.getContext().getDeclAlign(E->getDecl()).getQuantity();
1237  return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
1238}
1239
1240LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1241  // __extension__ doesn't affect lvalue-ness.
1242  if (E->getOpcode() == UO_Extension)
1243    return EmitLValue(E->getSubExpr());
1244
1245  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1246  switch (E->getOpcode()) {
1247  default: assert(0 && "Unknown unary operator lvalue!");
1248  case UO_Deref: {
1249    QualType T = E->getSubExpr()->getType()->getPointeeType();
1250    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1251
1252    LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
1253    LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
1254
1255    // We should not generate __weak write barrier on indirect reference
1256    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1257    // But, we continue to generate __strong write barrier on indirect write
1258    // into a pointer to object.
1259    if (getContext().getLangOptions().ObjC1 &&
1260        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1261        LV.isObjCWeak())
1262      LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1263    return LV;
1264  }
1265  case UO_Real:
1266  case UO_Imag: {
1267    LValue LV = EmitLValue(E->getSubExpr());
1268    unsigned Idx = E->getOpcode() == UO_Imag;
1269    return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
1270                                                    Idx, "idx"),
1271                          ExprTy);
1272  }
1273  case UO_PreInc:
1274  case UO_PreDec: {
1275    LValue LV = EmitLValue(E->getSubExpr());
1276    bool isInc = E->getOpcode() == UO_PreInc;
1277
1278    if (E->getType()->isAnyComplexType())
1279      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1280    else
1281      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1282    return LV;
1283  }
1284  }
1285}
1286
1287LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1288  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
1289                        E->getType());
1290}
1291
1292LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1293  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1294                        E->getType());
1295}
1296
1297
1298LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1299  switch (E->getIdentType()) {
1300  default:
1301    return EmitUnsupportedLValue(E, "predefined expression");
1302
1303  case PredefinedExpr::Func:
1304  case PredefinedExpr::Function:
1305  case PredefinedExpr::PrettyFunction: {
1306    unsigned Type = E->getIdentType();
1307    std::string GlobalVarName;
1308
1309    switch (Type) {
1310    default: assert(0 && "Invalid type");
1311    case PredefinedExpr::Func:
1312      GlobalVarName = "__func__.";
1313      break;
1314    case PredefinedExpr::Function:
1315      GlobalVarName = "__FUNCTION__.";
1316      break;
1317    case PredefinedExpr::PrettyFunction:
1318      GlobalVarName = "__PRETTY_FUNCTION__.";
1319      break;
1320    }
1321
1322    llvm::StringRef FnName = CurFn->getName();
1323    if (FnName.startswith("\01"))
1324      FnName = FnName.substr(1);
1325    GlobalVarName += FnName;
1326
1327    const Decl *CurDecl = CurCodeDecl;
1328    if (CurDecl == 0)
1329      CurDecl = getContext().getTranslationUnitDecl();
1330
1331    std::string FunctionName =
1332      PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl);
1333
1334    llvm::Constant *C =
1335      CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1336    return MakeAddrLValue(C, E->getType());
1337  }
1338  }
1339}
1340
1341llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1342  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1343
1344  // If we are not optimzing, don't collapse all calls to trap in the function
1345  // to the same call, that way, in the debugger they can see which operation
1346  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1347  // to just one per function to save on codesize.
1348  if (GCO.OptimizationLevel && TrapBB)
1349    return TrapBB;
1350
1351  llvm::BasicBlock *Cont = 0;
1352  if (HaveInsertPoint()) {
1353    Cont = createBasicBlock("cont");
1354    EmitBranch(Cont);
1355  }
1356  TrapBB = createBasicBlock("trap");
1357  EmitBlock(TrapBB);
1358
1359  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1360  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1361  TrapCall->setDoesNotReturn();
1362  TrapCall->setDoesNotThrow();
1363  Builder.CreateUnreachable();
1364
1365  if (Cont)
1366    EmitBlock(Cont);
1367  return TrapBB;
1368}
1369
1370/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1371/// array to pointer, return the array subexpression.
1372static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1373  // If this isn't just an array->pointer decay, bail out.
1374  const CastExpr *CE = dyn_cast<CastExpr>(E);
1375  if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay)
1376    return 0;
1377
1378  // If this is a decay from variable width array, bail out.
1379  const Expr *SubExpr = CE->getSubExpr();
1380  if (SubExpr->getType()->isVariableArrayType())
1381    return 0;
1382
1383  return SubExpr;
1384}
1385
1386LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1387  // The index must always be an integer, which is not an aggregate.  Emit it.
1388  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1389  QualType IdxTy  = E->getIdx()->getType();
1390  bool IdxSigned = IdxTy->isSignedIntegerType();
1391
1392  // If the base is a vector type, then we are forming a vector element lvalue
1393  // with this subscript.
1394  if (E->getBase()->getType()->isVectorType()) {
1395    // Emit the vector as an lvalue to get its address.
1396    LValue LHS = EmitLValue(E->getBase());
1397    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1398    Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vidx");
1399    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1400                                 E->getBase()->getType().getCVRQualifiers());
1401  }
1402
1403  // Extend or truncate the index type to 32 or 64-bits.
1404  if (!Idx->getType()->isIntegerTy(LLVMPointerWidth))
1405    Idx = Builder.CreateIntCast(Idx, IntPtrTy,
1406                                IdxSigned, "idxprom");
1407
1408  // FIXME: As llvm implements the object size checking, this can come out.
1409  if (CatchUndefined) {
1410    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1411      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1412        if (ICE->getCastKind() == CK_ArrayToPointerDecay) {
1413          if (const ConstantArrayType *CAT
1414              = getContext().getAsConstantArrayType(DRE->getType())) {
1415            llvm::APInt Size = CAT->getSize();
1416            llvm::BasicBlock *Cont = createBasicBlock("cont");
1417            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1418                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1419                                 Cont, getTrapBB());
1420            EmitBlock(Cont);
1421          }
1422        }
1423      }
1424    }
1425  }
1426
1427  // We know that the pointer points to a type of the correct size, unless the
1428  // size is a VLA or Objective-C interface.
1429  llvm::Value *Address = 0;
1430  if (const VariableArrayType *VAT =
1431        getContext().getAsVariableArrayType(E->getType())) {
1432    llvm::Value *VLASize = GetVLASize(VAT);
1433
1434    Idx = Builder.CreateMul(Idx, VLASize);
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
1441    Address = Builder.CreateInBoundsGEP(Builder.CreateBitCast(Base, i8PTy),
1442                                        Idx, "arrayidx");
1443    Address = Builder.CreateBitCast(Address, Base->getType());
1444  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1445    // Indexing over an interface, as in "NSString *P; P[4];"
1446    llvm::Value *InterfaceSize =
1447      llvm::ConstantInt::get(Idx->getType(),
1448          getContext().getTypeSizeInChars(OIT).getQuantity());
1449
1450    Idx = Builder.CreateMul(Idx, InterfaceSize);
1451
1452    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1453
1454    // The base must be a pointer, which is not an aggregate.  Emit it.
1455    llvm::Value *Base = EmitScalarExpr(E->getBase());
1456    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1457                                Idx, "arrayidx");
1458    Address = Builder.CreateBitCast(Address, Base->getType());
1459  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1460    // If this is A[i] where A is an array, the frontend will have decayed the
1461    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1462    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1463    // "gep x, i" here.  Emit one "gep A, 0, i".
1464    assert(Array->getType()->isArrayType() &&
1465           "Array to pointer decay must have array source type!");
1466    llvm::Value *ArrayPtr = EmitLValue(Array).getAddress();
1467    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1468    llvm::Value *Args[] = { Zero, Idx };
1469
1470    Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1471  } else {
1472    // The base must be a pointer, which is not an aggregate.  Emit it.
1473    llvm::Value *Base = EmitScalarExpr(E->getBase());
1474    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1475  }
1476
1477  QualType T = E->getBase()->getType()->getPointeeType();
1478  assert(!T.isNull() &&
1479         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1480
1481  LValue LV = MakeAddrLValue(Address, T);
1482  LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
1483
1484  if (getContext().getLangOptions().ObjC1 &&
1485      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1486    LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1487    setObjCGCLValueClass(getContext(), E, LV);
1488  }
1489  return LV;
1490}
1491
1492static
1493llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1494                                       llvm::SmallVector<unsigned, 4> &Elts) {
1495  llvm::SmallVector<llvm::Constant*, 4> CElts;
1496
1497  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1498  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1499    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1500
1501  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1502}
1503
1504LValue CodeGenFunction::
1505EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1506  // Emit the base vector as an l-value.
1507  LValue Base;
1508
1509  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1510  if (E->isArrow()) {
1511    // If it is a pointer to a vector, emit the address and form an lvalue with
1512    // it.
1513    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1514    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1515    Base = MakeAddrLValue(Ptr, PT->getPointeeType());
1516    Base.getQuals().removeObjCGCAttr();
1517  } else if (E->getBase()->isLvalue(getContext()) == Expr::LV_Valid) {
1518    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1519    // emit the base as an lvalue.
1520    assert(E->getBase()->getType()->isVectorType());
1521    Base = EmitLValue(E->getBase());
1522  } else {
1523    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1524    assert(E->getBase()->getType()->getAs<VectorType>() &&
1525           "Result must be a vector");
1526    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1527
1528    // Store the vector to memory (because LValue wants an address).
1529    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1530    Builder.CreateStore(Vec, VecMem);
1531    Base = MakeAddrLValue(VecMem, E->getBase()->getType());
1532  }
1533
1534  // Encode the element access list into a vector of unsigned indices.
1535  llvm::SmallVector<unsigned, 4> Indices;
1536  E->getEncodedElementAccess(Indices);
1537
1538  if (Base.isSimple()) {
1539    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1540    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1541                                    Base.getVRQualifiers());
1542  }
1543  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1544
1545  llvm::Constant *BaseElts = Base.getExtVectorElts();
1546  llvm::SmallVector<llvm::Constant *, 4> CElts;
1547
1548  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1549    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1550      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1551    else
1552      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1553  }
1554  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1555  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1556                                  Base.getVRQualifiers());
1557}
1558
1559LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1560  bool isNonGC = false;
1561  Expr *BaseExpr = E->getBase();
1562  llvm::Value *BaseValue = NULL;
1563  Qualifiers BaseQuals;
1564
1565  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1566  if (E->isArrow()) {
1567    BaseValue = EmitScalarExpr(BaseExpr);
1568    const PointerType *PTy =
1569      BaseExpr->getType()->getAs<PointerType>();
1570    BaseQuals = PTy->getPointeeType().getQualifiers();
1571  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1572             isa<ObjCImplicitSetterGetterRefExpr>(
1573               BaseExpr->IgnoreParens())) {
1574    RValue RV = EmitObjCPropertyGet(BaseExpr);
1575    BaseValue = RV.getAggregateAddr();
1576    BaseQuals = BaseExpr->getType().getQualifiers();
1577  } else {
1578    LValue BaseLV = EmitLValue(BaseExpr);
1579    if (BaseLV.isNonGC())
1580      isNonGC = true;
1581    // FIXME: this isn't right for bitfields.
1582    BaseValue = BaseLV.getAddress();
1583    QualType BaseTy = BaseExpr->getType();
1584    BaseQuals = BaseTy.getQualifiers();
1585  }
1586
1587  NamedDecl *ND = E->getMemberDecl();
1588  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1589    LValue LV = EmitLValueForField(BaseValue, Field,
1590                                   BaseQuals.getCVRQualifiers());
1591    LV.setNonGC(isNonGC);
1592    setObjCGCLValueClass(getContext(), E, LV);
1593    return LV;
1594  }
1595
1596  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1597    return EmitGlobalVarDeclLValue(*this, E, VD);
1598
1599  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1600    return EmitFunctionDeclLValue(*this, E, FD);
1601
1602  assert(false && "Unhandled member declaration!");
1603  return LValue();
1604}
1605
1606LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue,
1607                                              const FieldDecl *Field,
1608                                              unsigned CVRQualifiers) {
1609  const CGRecordLayout &RL =
1610    CGM.getTypes().getCGRecordLayout(Field->getParent());
1611  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1612  return LValue::MakeBitfield(BaseValue, Info,
1613                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1614}
1615
1616/// EmitLValueForAnonRecordField - Given that the field is a member of
1617/// an anonymous struct or union buried inside a record, and given
1618/// that the base value is a pointer to the enclosing record, derive
1619/// an lvalue for the ultimate field.
1620LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1621                                                     const FieldDecl *Field,
1622                                                     unsigned CVRQualifiers) {
1623  llvm::SmallVector<const FieldDecl *, 8> Path;
1624  Path.push_back(Field);
1625
1626  while (Field->getParent()->isAnonymousStructOrUnion()) {
1627    const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
1628    if (!isa<FieldDecl>(VD)) break;
1629    Field = cast<FieldDecl>(VD);
1630    Path.push_back(Field);
1631  }
1632
1633  llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
1634    I = Path.rbegin(), E = Path.rend();
1635  while (true) {
1636    LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
1637    if (++I == E) return LV;
1638
1639    assert(LV.isSimple());
1640    BaseValue = LV.getAddress();
1641    CVRQualifiers |= LV.getVRQualifiers();
1642  }
1643}
1644
1645LValue CodeGenFunction::EmitLValueForField(llvm::Value *BaseValue,
1646                                           const FieldDecl *Field,
1647                                           unsigned CVRQualifiers) {
1648  if (Field->isBitField())
1649    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1650
1651  const CGRecordLayout &RL =
1652    CGM.getTypes().getCGRecordLayout(Field->getParent());
1653  unsigned idx = RL.getLLVMFieldNo(Field);
1654  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1655
1656  // Match union field type.
1657  if (Field->getParent()->isUnion()) {
1658    const llvm::Type *FieldTy =
1659      CGM.getTypes().ConvertTypeForMem(Field->getType());
1660    const llvm::PointerType *BaseTy =
1661      cast<llvm::PointerType>(BaseValue->getType());
1662    unsigned AS = BaseTy->getAddressSpace();
1663    V = Builder.CreateBitCast(V,
1664                              llvm::PointerType::get(FieldTy, AS),
1665                              "tmp");
1666  }
1667  if (Field->getType()->isReferenceType())
1668    V = Builder.CreateLoad(V, "tmp");
1669
1670  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1671  LValue LV = MakeAddrLValue(V, Field->getType(), Alignment);
1672  LV.getQuals().addCVRQualifiers(CVRQualifiers);
1673
1674  // __weak attribute on a field is ignored.
1675  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
1676    LV.getQuals().removeObjCGCAttr();
1677
1678  return LV;
1679}
1680
1681LValue
1682CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue,
1683                                                  const FieldDecl *Field,
1684                                                  unsigned CVRQualifiers) {
1685  QualType FieldType = Field->getType();
1686
1687  if (!FieldType->isReferenceType())
1688    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1689
1690  const CGRecordLayout &RL =
1691    CGM.getTypes().getCGRecordLayout(Field->getParent());
1692  unsigned idx = RL.getLLVMFieldNo(Field);
1693  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1694
1695  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1696
1697  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1698  return MakeAddrLValue(V, FieldType, Alignment);
1699}
1700
1701LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
1702  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1703  const Expr *InitExpr = E->getInitializer();
1704  LValue Result = MakeAddrLValue(DeclPtr, E->getType());
1705
1706  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false, /*Init*/ true);
1707
1708  return Result;
1709}
1710
1711LValue
1712CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator *E) {
1713  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1714    if (int Cond = ConstantFoldsToSimpleInteger(E->getCond())) {
1715      Expr *Live = Cond == 1 ? E->getLHS() : E->getRHS();
1716      if (Live)
1717        return EmitLValue(Live);
1718    }
1719
1720    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1721    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1722    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1723
1724    if (E->getLHS())
1725      EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1726    else {
1727      Expr *save = E->getSAVE();
1728      assert(save && "VisitConditionalOperator - save is null");
1729      // Intentianlly not doing direct assignment to ConditionalSaveExprs[save]
1730      LValue SaveVal = EmitLValue(save);
1731      ConditionalSaveLValueExprs[save] = SaveVal;
1732      EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1733    }
1734
1735    // Any temporaries created here are conditional.
1736    BeginConditionalBranch();
1737    EmitBlock(LHSBlock);
1738    LValue LHS = EmitLValue(E->getTrueExpr());
1739
1740    EndConditionalBranch();
1741
1742    if (!LHS.isSimple())
1743      return EmitUnsupportedLValue(E, "conditional operator");
1744
1745    // FIXME: We shouldn't need an alloca for this.
1746    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1747    Builder.CreateStore(LHS.getAddress(), Temp);
1748    EmitBranch(ContBlock);
1749
1750    // Any temporaries created here are conditional.
1751    BeginConditionalBranch();
1752    EmitBlock(RHSBlock);
1753    LValue RHS = EmitLValue(E->getRHS());
1754    EndConditionalBranch();
1755    if (!RHS.isSimple())
1756      return EmitUnsupportedLValue(E, "conditional operator");
1757
1758    Builder.CreateStore(RHS.getAddress(), Temp);
1759    EmitBranch(ContBlock);
1760
1761    EmitBlock(ContBlock);
1762
1763    Temp = Builder.CreateLoad(Temp, "lv");
1764    return MakeAddrLValue(Temp, E->getType());
1765  }
1766
1767  // ?: here should be an aggregate.
1768  assert((hasAggregateLLVMType(E->getType()) &&
1769          !E->getType()->isAnyComplexType()) &&
1770         "Unexpected conditional operator!");
1771
1772  return EmitAggExprToLValue(E);
1773}
1774
1775/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1776/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1777/// otherwise if a cast is needed by the code generator in an lvalue context,
1778/// then it must mean that we need the address of an aggregate in order to
1779/// access one of its fields.  This can happen for all the reasons that casts
1780/// are permitted with aggregate result, including noop aggregate casts, and
1781/// cast from scalar to union.
1782LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1783  switch (E->getCastKind()) {
1784  case CK_ToVoid:
1785    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1786
1787  case CK_Dependent:
1788    llvm_unreachable("dependent cast kind in IR gen!");
1789
1790  case CK_NoOp:
1791    if (E->getSubExpr()->Classify(getContext()).getKind()
1792                                          != Expr::Classification::CL_PRValue) {
1793      LValue LV = EmitLValue(E->getSubExpr());
1794      if (LV.isPropertyRef() || LV.isKVCRef()) {
1795        QualType QT = E->getSubExpr()->getType();
1796        RValue RV =
1797          LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
1798                             : EmitLoadOfKVCRefLValue(LV, QT);
1799        assert(!RV.isScalar() && "EmitCastLValue-scalar cast of property ref");
1800        llvm::Value *V = RV.getAggregateAddr();
1801        return MakeAddrLValue(V, QT);
1802      }
1803      return LV;
1804    }
1805    // Fall through to synthesize a temporary.
1806
1807  case CK_Unknown:
1808  case CK_BitCast:
1809  case CK_ArrayToPointerDecay:
1810  case CK_FunctionToPointerDecay:
1811  case CK_NullToMemberPointer:
1812  case CK_NullToPointer:
1813  case CK_IntegralToPointer:
1814  case CK_PointerToIntegral:
1815  case CK_PointerToBoolean:
1816  case CK_VectorSplat:
1817  case CK_IntegralCast:
1818  case CK_IntegralToBoolean:
1819  case CK_IntegralToFloating:
1820  case CK_FloatingToIntegral:
1821  case CK_FloatingToBoolean:
1822  case CK_FloatingCast:
1823  case CK_FloatingRealToComplex:
1824  case CK_FloatingComplexToReal:
1825  case CK_FloatingComplexToBoolean:
1826  case CK_FloatingComplexCast:
1827  case CK_FloatingComplexToIntegralComplex:
1828  case CK_IntegralRealToComplex:
1829  case CK_IntegralComplexToReal:
1830  case CK_IntegralComplexToBoolean:
1831  case CK_IntegralComplexCast:
1832  case CK_IntegralComplexToFloatingComplex:
1833  case CK_DerivedToBaseMemberPointer:
1834  case CK_BaseToDerivedMemberPointer:
1835  case CK_MemberPointerToBoolean:
1836  case CK_AnyPointerToBlockPointerCast: {
1837    // These casts only produce lvalues when we're binding a reference to a
1838    // temporary realized from a (converted) pure rvalue. Emit the expression
1839    // as a value, copy it into a temporary, and return an lvalue referring to
1840    // that temporary.
1841    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
1842    EmitAnyExprToMem(E, V, false, false);
1843    return MakeAddrLValue(V, E->getType());
1844  }
1845
1846  case CK_Dynamic: {
1847    LValue LV = EmitLValue(E->getSubExpr());
1848    llvm::Value *V = LV.getAddress();
1849    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1850    return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
1851  }
1852
1853  case CK_ConstructorConversion:
1854  case CK_UserDefinedConversion:
1855  case CK_AnyPointerToObjCPointerCast:
1856    return EmitLValue(E->getSubExpr());
1857
1858  case CK_UncheckedDerivedToBase:
1859  case CK_DerivedToBase: {
1860    const RecordType *DerivedClassTy =
1861      E->getSubExpr()->getType()->getAs<RecordType>();
1862    CXXRecordDecl *DerivedClassDecl =
1863      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1864
1865    LValue LV = EmitLValue(E->getSubExpr());
1866    llvm::Value *This;
1867    if (LV.isPropertyRef() || LV.isKVCRef()) {
1868      QualType QT = E->getSubExpr()->getType();
1869      RValue RV =
1870        LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
1871                           : EmitLoadOfKVCRefLValue(LV, QT);
1872      assert (!RV.isScalar() && "EmitCastLValue");
1873      This = RV.getAggregateAddr();
1874    }
1875    else
1876      This = LV.getAddress();
1877
1878    // Perform the derived-to-base conversion
1879    llvm::Value *Base =
1880      GetAddressOfBaseClass(This, DerivedClassDecl,
1881                            E->path_begin(), E->path_end(),
1882                            /*NullCheckValue=*/false);
1883
1884    return MakeAddrLValue(Base, E->getType());
1885  }
1886  case CK_ToUnion:
1887    return EmitAggExprToLValue(E);
1888  case CK_BaseToDerived: {
1889    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1890    CXXRecordDecl *DerivedClassDecl =
1891      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1892
1893    LValue LV = EmitLValue(E->getSubExpr());
1894
1895    // Perform the base-to-derived conversion
1896    llvm::Value *Derived =
1897      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1898                               E->path_begin(), E->path_end(),
1899                               /*NullCheckValue=*/false);
1900
1901    return MakeAddrLValue(Derived, E->getType());
1902  }
1903  case CK_LValueBitCast: {
1904    // This must be a reinterpret_cast (or c-style equivalent).
1905    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1906
1907    LValue LV = EmitLValue(E->getSubExpr());
1908    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1909                                           ConvertType(CE->getTypeAsWritten()));
1910    return MakeAddrLValue(V, E->getType());
1911  }
1912  case CK_ObjCObjectLValueCast: {
1913    LValue LV = EmitLValue(E->getSubExpr());
1914    QualType ToType = getContext().getLValueReferenceType(E->getType());
1915    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1916                                           ConvertType(ToType));
1917    return MakeAddrLValue(V, E->getType());
1918  }
1919  }
1920
1921  llvm_unreachable("Unhandled lvalue cast kind?");
1922}
1923
1924LValue CodeGenFunction::EmitNullInitializationLValue(
1925                                              const CXXScalarValueInitExpr *E) {
1926  QualType Ty = E->getType();
1927  LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
1928  EmitNullInitialization(LV.getAddress(), Ty);
1929  return LV;
1930}
1931
1932//===--------------------------------------------------------------------===//
1933//                             Expression Emission
1934//===--------------------------------------------------------------------===//
1935
1936
1937RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
1938                                     ReturnValueSlot ReturnValue) {
1939  // Builtins never have block type.
1940  if (E->getCallee()->getType()->isBlockPointerType())
1941    return EmitBlockCallExpr(E, ReturnValue);
1942
1943  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1944    return EmitCXXMemberCallExpr(CE, ReturnValue);
1945
1946  const Decl *TargetDecl = 0;
1947  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1948    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1949      TargetDecl = DRE->getDecl();
1950      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1951        if (unsigned builtinID = FD->getBuiltinID())
1952          return EmitBuiltinExpr(FD, builtinID, E);
1953    }
1954  }
1955
1956  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1957    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1958      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
1959
1960  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1961    // C++ [expr.pseudo]p1:
1962    //   The result shall only be used as the operand for the function call
1963    //   operator (), and the result of such a call has type void. The only
1964    //   effect is the evaluation of the postfix-expression before the dot or
1965    //   arrow.
1966    EmitScalarExpr(E->getCallee());
1967    return RValue::get(0);
1968  }
1969
1970  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1971  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
1972                  E->arg_begin(), E->arg_end(), TargetDecl);
1973}
1974
1975LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1976  // Comma expressions just emit their LHS then their RHS as an l-value.
1977  if (E->getOpcode() == BO_Comma) {
1978    EmitAnyExpr(E->getLHS());
1979    EnsureInsertPoint();
1980    return EmitLValue(E->getRHS());
1981  }
1982
1983  if (E->getOpcode() == BO_PtrMemD ||
1984      E->getOpcode() == BO_PtrMemI)
1985    return EmitPointerToDataMemberBinaryExpr(E);
1986
1987  // Can only get l-value for binary operator expressions which are a
1988  // simple assignment of aggregate type.
1989  if (E->getOpcode() != BO_Assign)
1990    return EmitUnsupportedLValue(E, "binary l-value expression");
1991
1992  if (!hasAggregateLLVMType(E->getType())) {
1993    // Emit the LHS as an l-value.
1994    LValue LV = EmitLValue(E->getLHS());
1995    // Store the value through the l-value.
1996    EmitStoreThroughLValue(EmitAnyExpr(E->getRHS()), LV, E->getType());
1997    return LV;
1998  }
1999
2000  return EmitAggExprToLValue(E);
2001}
2002
2003LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
2004  RValue RV = EmitCallExpr(E);
2005
2006  if (!RV.isScalar())
2007    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2008
2009  assert(E->getCallReturnType()->isReferenceType() &&
2010         "Can't have a scalar return unless the return type is a "
2011         "reference type!");
2012
2013  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2014}
2015
2016LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
2017  // FIXME: This shouldn't require another copy.
2018  return EmitAggExprToLValue(E);
2019}
2020
2021LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
2022  assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
2023         && "binding l-value to type which needs a temporary");
2024  AggValueSlot Slot = CreateAggTemp(E->getType(), "tmp");
2025  EmitCXXConstructExpr(E, Slot);
2026  return MakeAddrLValue(Slot.getAddr(), E->getType());
2027}
2028
2029LValue
2030CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
2031  return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
2032}
2033
2034LValue
2035CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
2036  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
2037  Slot.setLifetimeExternallyManaged();
2038  EmitAggExpr(E->getSubExpr(), Slot);
2039  EmitCXXTemporary(E->getTemporary(), Slot.getAddr());
2040  return MakeAddrLValue(Slot.getAddr(), E->getType());
2041}
2042
2043LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
2044  RValue RV = EmitObjCMessageExpr(E);
2045
2046  if (!RV.isScalar())
2047    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2048
2049  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2050         "Can't have a scalar return unless the return type is a "
2051         "reference type!");
2052
2053  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2054}
2055
2056LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2057  llvm::Value *V =
2058    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2059  return MakeAddrLValue(V, E->getType());
2060}
2061
2062llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2063                                             const ObjCIvarDecl *Ivar) {
2064  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2065}
2066
2067LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2068                                          llvm::Value *BaseValue,
2069                                          const ObjCIvarDecl *Ivar,
2070                                          unsigned CVRQualifiers) {
2071  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2072                                                   Ivar, CVRQualifiers);
2073}
2074
2075LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2076  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2077  llvm::Value *BaseValue = 0;
2078  const Expr *BaseExpr = E->getBase();
2079  Qualifiers BaseQuals;
2080  QualType ObjectTy;
2081  if (E->isArrow()) {
2082    BaseValue = EmitScalarExpr(BaseExpr);
2083    ObjectTy = BaseExpr->getType()->getPointeeType();
2084    BaseQuals = ObjectTy.getQualifiers();
2085  } else {
2086    LValue BaseLV = EmitLValue(BaseExpr);
2087    // FIXME: this isn't right for bitfields.
2088    BaseValue = BaseLV.getAddress();
2089    ObjectTy = BaseExpr->getType();
2090    BaseQuals = ObjectTy.getQualifiers();
2091  }
2092
2093  LValue LV =
2094    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2095                      BaseQuals.getCVRQualifiers());
2096  setObjCGCLValueClass(getContext(), E, LV);
2097  return LV;
2098}
2099
2100LValue
2101CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
2102  // This is a special l-value that just issues sends when we load or store
2103  // through it.
2104  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
2105}
2106
2107LValue CodeGenFunction::EmitObjCKVCRefLValue(
2108                                const ObjCImplicitSetterGetterRefExpr *E) {
2109  // This is a special l-value that just issues sends when we load or store
2110  // through it.
2111  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
2112}
2113
2114LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2115  // Can only get l-value for message expression returning aggregate type
2116  RValue RV = EmitAnyExprToTemp(E);
2117  return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2118}
2119
2120RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2121                                 ReturnValueSlot ReturnValue,
2122                                 CallExpr::const_arg_iterator ArgBeg,
2123                                 CallExpr::const_arg_iterator ArgEnd,
2124                                 const Decl *TargetDecl) {
2125  // Get the actual function type. The callee type will always be a pointer to
2126  // function type or a block pointer type.
2127  assert(CalleeType->isFunctionPointerType() &&
2128         "Call must have function pointer type!");
2129
2130  CalleeType = getContext().getCanonicalType(CalleeType);
2131
2132  const FunctionType *FnType
2133    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2134  QualType ResultType = FnType->getResultType();
2135
2136  CallArgList Args;
2137  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2138
2139  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2140                  Callee, ReturnValue, Args, TargetDecl);
2141}
2142
2143LValue CodeGenFunction::
2144EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2145  llvm::Value *BaseV;
2146  if (E->getOpcode() == BO_PtrMemI)
2147    BaseV = EmitScalarExpr(E->getLHS());
2148  else
2149    BaseV = EmitLValue(E->getLHS()).getAddress();
2150
2151  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2152
2153  const MemberPointerType *MPT
2154    = E->getRHS()->getType()->getAs<MemberPointerType>();
2155
2156  llvm::Value *AddV =
2157    CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT);
2158
2159  return MakeAddrLValue(AddV, MPT->getPointeeType());
2160}
2161
2162