CGExpr.cpp revision 130c69e969a785ff3be9e909f8eba7f89e42ac10 
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 "CGObjCRuntime.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/DeclObjC.h"
20#include "llvm/Target/TargetData.h"
21using namespace clang;
22using namespace CodeGen;
23
24//===--------------------------------------------------------------------===//
25//                        Miscellaneous Helper Methods
26//===--------------------------------------------------------------------===//
27
28/// CreateTempAlloca - This creates a alloca and inserts it into the entry
29/// block.
30llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
31                                                    const llvm::Twine &Name) {
32  if (!Builder.isNamePreserving())
33    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
34  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
35}
36
37/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
38/// expression and compare the result against zero, returning an Int1Ty value.
39llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
40  QualType BoolTy = getContext().BoolTy;
41  if (!E->getType()->isAnyComplexType())
42    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
43
44  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
45}
46
47/// EmitAnyExpr - Emit code to compute the specified expression which can have
48/// any type.  The result is returned as an RValue struct.  If this is an
49/// aggregate expression, the aggloc/agglocvolatile arguments indicate where the
50/// result should be returned.
51RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc,
52                                    bool IsAggLocVolatile, bool IgnoreResult,
53                                    bool IsInitializer) {
54  if (!hasAggregateLLVMType(E->getType()))
55    return RValue::get(EmitScalarExpr(E, IgnoreResult));
56  else if (E->getType()->isAnyComplexType())
57    return RValue::getComplex(EmitComplexExpr(E, false, false,
58                                              IgnoreResult, IgnoreResult));
59
60  EmitAggExpr(E, AggLoc, IsAggLocVolatile, IgnoreResult, IsInitializer);
61  return RValue::getAggregate(AggLoc, IsAggLocVolatile);
62}
63
64/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
65/// always be accessible even if no aggregate location is provided.
66RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E,
67                                          bool IsAggLocVolatile,
68                                          bool IsInitializer) {
69  llvm::Value *AggLoc = 0;
70
71  if (hasAggregateLLVMType(E->getType()) &&
72      !E->getType()->isAnyComplexType())
73    AggLoc = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp");
74  return EmitAnyExpr(E, AggLoc, IsAggLocVolatile, /*IgnoreResult=*/false,
75                     IsInitializer);
76}
77
78RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
79                                                   QualType DestType,
80                                                   bool IsInitializer) {
81  bool ShouldDestroyTemporaries = false;
82  unsigned OldNumLiveTemporaries = 0;
83
84  if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
85    ShouldDestroyTemporaries = TE->shouldDestroyTemporaries();
86
87    // Keep track of the current cleanup stack depth.
88    if (ShouldDestroyTemporaries)
89      OldNumLiveTemporaries = LiveTemporaries.size();
90
91    E = TE->getSubExpr();
92  }
93
94  RValue Val;
95  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
96    // Emit the expr as an lvalue.
97    LValue LV = EmitLValue(E);
98    if (LV.isSimple())
99      return RValue::get(LV.getAddress());
100    Val = EmitLoadOfLValue(LV, E->getType());
101
102    if (ShouldDestroyTemporaries) {
103      // Pop temporaries.
104      while (LiveTemporaries.size() > OldNumLiveTemporaries)
105        PopCXXTemporary();
106    }
107  } else {
108    const CXXRecordDecl *BaseClassDecl = 0;
109    const CXXRecordDecl *DerivedClassDecl = 0;
110
111    if (const CastExpr *CE =
112          dyn_cast<CastExpr>(E->IgnoreParenNoopCasts(getContext()))) {
113      if (CE->getCastKind() == CastExpr::CK_DerivedToBase) {
114        E = CE->getSubExpr();
115
116        BaseClassDecl =
117          cast<CXXRecordDecl>(CE->getType()->getAs<RecordType>()->getDecl());
118        DerivedClassDecl =
119          cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
120      }
121    }
122
123    Val = EmitAnyExprToTemp(E, /*IsAggLocVolatile=*/false,
124                            IsInitializer);
125
126    if (ShouldDestroyTemporaries) {
127      // Pop temporaries.
128      while (LiveTemporaries.size() > OldNumLiveTemporaries)
129        PopCXXTemporary();
130    }
131
132    if (IsInitializer) {
133      // We might have to destroy the temporary variable.
134      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
135        if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
136          if (!ClassDecl->hasTrivialDestructor()) {
137            const CXXDestructorDecl *Dtor =
138              ClassDecl->getDestructor(getContext());
139
140            DelayedCleanupBlock scope(*this);
141            EmitCXXDestructorCall(Dtor, Dtor_Complete, Val.getAggregateAddr());
142          }
143        }
144      }
145    }
146
147    // Check if need to perform the derived-to-base cast.
148    if (BaseClassDecl) {
149      llvm::Value *Derived = Val.getAggregateAddr();
150      llvm::Value *Base =
151        GetAddressOfBaseClass(Derived, DerivedClassDecl, BaseClassDecl,
152                              /*NullCheckValue=*/false);
153      return RValue::get(Base);
154    }
155  }
156
157  if (Val.isAggregate()) {
158    Val = RValue::get(Val.getAggregateAddr());
159  } else {
160    // Create a temporary variable that we can bind the reference to.
161    llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()),
162                                         "reftmp");
163    if (Val.isScalar())
164      EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
165    else
166      StoreComplexToAddr(Val.getComplexVal(), Temp, false);
167    Val = RValue::get(Temp);
168  }
169
170  return Val;
171}
172
173
174/// getAccessedFieldNo - Given an encoded value and a result number, return the
175/// input field number being accessed.
176unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
177                                             const llvm::Constant *Elts) {
178  if (isa<llvm::ConstantAggregateZero>(Elts))
179    return 0;
180
181  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
182}
183
184
185//===----------------------------------------------------------------------===//
186//                         LValue Expression Emission
187//===----------------------------------------------------------------------===//
188
189RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
190  if (Ty->isVoidType())
191    return RValue::get(0);
192
193  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
194    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
195    llvm::Value *U = llvm::UndefValue::get(EltTy);
196    return RValue::getComplex(std::make_pair(U, U));
197  }
198
199  if (hasAggregateLLVMType(Ty)) {
200    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
201    return RValue::getAggregate(llvm::UndefValue::get(LTy));
202  }
203
204  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
205}
206
207RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
208                                              const char *Name) {
209  ErrorUnsupported(E, Name);
210  return GetUndefRValue(E->getType());
211}
212
213LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
214                                              const char *Name) {
215  ErrorUnsupported(E, Name);
216  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
217  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
218                          MakeQualifiers(E->getType()));
219}
220
221/// EmitLValue - Emit code to compute a designator that specifies the location
222/// of the expression.
223///
224/// This can return one of two things: a simple address or a bitfield reference.
225/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
226/// an LLVM pointer type.
227///
228/// If this returns a bitfield reference, nothing about the pointee type of the
229/// LLVM value is known: For example, it may not be a pointer to an integer.
230///
231/// If this returns a normal address, and if the lvalue's C type is fixed size,
232/// this method guarantees that the returned pointer type will point to an LLVM
233/// type of the same size of the lvalue's type.  If the lvalue has a variable
234/// length type, this is not possible.
235///
236LValue CodeGenFunction::EmitLValue(const Expr *E) {
237  switch (E->getStmtClass()) {
238  default: return EmitUnsupportedLValue(E, "l-value expression");
239
240  case Expr::BinaryOperatorClass:
241    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
242  case Expr::CallExprClass:
243  case Expr::CXXMemberCallExprClass:
244  case Expr::CXXOperatorCallExprClass:
245    return EmitCallExprLValue(cast<CallExpr>(E));
246  case Expr::VAArgExprClass:
247    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
248  case Expr::DeclRefExprClass:
249    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
250  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
251  case Expr::PredefinedExprClass:
252    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
253  case Expr::StringLiteralClass:
254    return EmitStringLiteralLValue(cast<StringLiteral>(E));
255  case Expr::ObjCEncodeExprClass:
256    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
257
258  case Expr::BlockDeclRefExprClass:
259    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
260
261  case Expr::CXXTemporaryObjectExprClass:
262  case Expr::CXXConstructExprClass:
263    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
264  case Expr::CXXBindTemporaryExprClass:
265    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
266  case Expr::CXXExprWithTemporariesClass:
267    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
268  case Expr::CXXZeroInitValueExprClass:
269    return EmitNullInitializationLValue(cast<CXXZeroInitValueExpr>(E));
270  case Expr::CXXDefaultArgExprClass:
271    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
272  case Expr::CXXTypeidExprClass:
273    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
274
275  case Expr::ObjCMessageExprClass:
276    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
277  case Expr::ObjCIvarRefExprClass:
278    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
279  case Expr::ObjCPropertyRefExprClass:
280    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
281  case Expr::ObjCImplicitSetterGetterRefExprClass:
282    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
283  case Expr::ObjCSuperExprClass:
284    return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
285
286  case Expr::StmtExprClass:
287    return EmitStmtExprLValue(cast<StmtExpr>(E));
288  case Expr::UnaryOperatorClass:
289    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
290  case Expr::ArraySubscriptExprClass:
291    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
292  case Expr::ExtVectorElementExprClass:
293    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
294  case Expr::MemberExprClass:
295    return EmitMemberExpr(cast<MemberExpr>(E));
296  case Expr::CompoundLiteralExprClass:
297    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
298  case Expr::ConditionalOperatorClass:
299    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
300  case Expr::ChooseExprClass:
301    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
302  case Expr::ImplicitCastExprClass:
303  case Expr::CStyleCastExprClass:
304  case Expr::CXXFunctionalCastExprClass:
305  case Expr::CXXStaticCastExprClass:
306  case Expr::CXXDynamicCastExprClass:
307  case Expr::CXXReinterpretCastExprClass:
308  case Expr::CXXConstCastExprClass:
309    return EmitCastLValue(cast<CastExpr>(E));
310  }
311}
312
313llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
314                                               QualType Ty) {
315  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
316  if (Volatile)
317    Load->setVolatile(true);
318
319  // Bool can have different representation in memory than in registers.
320  llvm::Value *V = Load;
321  if (Ty->isBooleanType())
322    if (V->getType() != llvm::Type::getInt1Ty(VMContext))
323      V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
324
325  return V;
326}
327
328void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
329                                        bool Volatile, QualType Ty) {
330
331  if (Ty->isBooleanType()) {
332    // Bool can have different representation in memory than in registers.
333    const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
334    Value = Builder.CreateIntCast(Value, DstPtr->getElementType(), false);
335  }
336  Builder.CreateStore(Value, Addr, Volatile);
337}
338
339/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
340/// method emits the address of the lvalue, then loads the result as an rvalue,
341/// returning the rvalue.
342RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
343  if (LV.isObjCWeak()) {
344    // load of a __weak object.
345    llvm::Value *AddrWeakObj = LV.getAddress();
346    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
347                                                             AddrWeakObj));
348  }
349
350  if (LV.isSimple()) {
351    llvm::Value *Ptr = LV.getAddress();
352    const llvm::Type *EltTy =
353      cast<llvm::PointerType>(Ptr->getType())->getElementType();
354
355    // Simple scalar l-value.
356    if (EltTy->isSingleValueType())
357      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
358                                          ExprType));
359
360    assert(ExprType->isFunctionType() && "Unknown scalar value");
361    return RValue::get(Ptr);
362  }
363
364  if (LV.isVectorElt()) {
365    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
366                                          LV.isVolatileQualified(), "tmp");
367    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
368                                                    "vecext"));
369  }
370
371  // If this is a reference to a subset of the elements of a vector, either
372  // shuffle the input or extract/insert them as appropriate.
373  if (LV.isExtVectorElt())
374    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
375
376  if (LV.isBitfield())
377    return EmitLoadOfBitfieldLValue(LV, ExprType);
378
379  if (LV.isPropertyRef())
380    return EmitLoadOfPropertyRefLValue(LV, ExprType);
381
382  assert(LV.isKVCRef() && "Unknown LValue type!");
383  return EmitLoadOfKVCRefLValue(LV, ExprType);
384}
385
386RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
387                                                 QualType ExprType) {
388  unsigned StartBit = LV.getBitfieldStartBit();
389  unsigned BitfieldSize = LV.getBitfieldSize();
390  llvm::Value *Ptr = LV.getBitfieldAddr();
391
392  const llvm::Type *EltTy =
393    cast<llvm::PointerType>(Ptr->getType())->getElementType();
394  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
395
396  // In some cases the bitfield may straddle two memory locations.  Currently we
397  // load the entire bitfield, then do the magic to sign-extend it if
398  // necessary. This results in somewhat more code than necessary for the common
399  // case (one load), since two shifts accomplish both the masking and sign
400  // extension.
401  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
402  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp");
403
404  // Shift to proper location.
405  if (StartBit)
406    Val = Builder.CreateLShr(Val, StartBit, "bf.lo");
407
408  // Mask off unused bits.
409  llvm::Constant *LowMask = llvm::ConstantInt::get(VMContext,
410                                llvm::APInt::getLowBitsSet(EltTySize, LowBits));
411  Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared");
412
413  // Fetch the high bits if necessary.
414  if (LowBits < BitfieldSize) {
415    unsigned HighBits = BitfieldSize - LowBits;
416    llvm::Value *HighPtr = Builder.CreateGEP(Ptr, llvm::ConstantInt::get(
417                            llvm::Type::getInt32Ty(VMContext), 1), "bf.ptr.hi");
418    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
419                                              LV.isVolatileQualified(),
420                                              "tmp");
421
422    // Mask off unused bits.
423    llvm::Constant *HighMask = llvm::ConstantInt::get(VMContext,
424                               llvm::APInt::getLowBitsSet(EltTySize, HighBits));
425    HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared");
426
427    // Shift to proper location and or in to bitfield value.
428    HighVal = Builder.CreateShl(HighVal, LowBits);
429    Val = Builder.CreateOr(Val, HighVal, "bf.val");
430  }
431
432  // Sign extend if necessary.
433  if (LV.isBitfieldSigned()) {
434    llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy,
435                                                    EltTySize - BitfieldSize);
436    Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits),
437                             ExtraBits, "bf.val.sext");
438  }
439
440  // The bitfield type and the normal type differ when the storage sizes differ
441  // (currently just _Bool).
442  Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp");
443
444  return RValue::get(Val);
445}
446
447RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
448                                                    QualType ExprType) {
449  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
450}
451
452RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
453                                               QualType ExprType) {
454  return EmitObjCPropertyGet(LV.getKVCRefExpr());
455}
456
457// If this is a reference to a subset of the elements of a vector, create an
458// appropriate shufflevector.
459RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
460                                                         QualType ExprType) {
461  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
462                                        LV.isVolatileQualified(), "tmp");
463
464  const llvm::Constant *Elts = LV.getExtVectorElts();
465
466  // If the result of the expression is a non-vector type, we must be extracting
467  // a single element.  Just codegen as an extractelement.
468  const VectorType *ExprVT = ExprType->getAs<VectorType>();
469  if (!ExprVT) {
470    unsigned InIdx = getAccessedFieldNo(0, Elts);
471    llvm::Value *Elt = llvm::ConstantInt::get(
472                                      llvm::Type::getInt32Ty(VMContext), InIdx);
473    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
474  }
475
476  // Always use shuffle vector to try to retain the original program structure
477  unsigned NumResultElts = ExprVT->getNumElements();
478
479  llvm::SmallVector<llvm::Constant*, 4> Mask;
480  for (unsigned i = 0; i != NumResultElts; ++i) {
481    unsigned InIdx = getAccessedFieldNo(i, Elts);
482    Mask.push_back(llvm::ConstantInt::get(
483                                     llvm::Type::getInt32Ty(VMContext), InIdx));
484  }
485
486  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
487  Vec = Builder.CreateShuffleVector(Vec,
488                                    llvm::UndefValue::get(Vec->getType()),
489                                    MaskV, "tmp");
490  return RValue::get(Vec);
491}
492
493
494
495/// EmitStoreThroughLValue - Store the specified rvalue into the specified
496/// lvalue, where both are guaranteed to the have the same type, and that type
497/// is 'Ty'.
498void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
499                                             QualType Ty) {
500  if (!Dst.isSimple()) {
501    if (Dst.isVectorElt()) {
502      // Read/modify/write the vector, inserting the new element.
503      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
504                                            Dst.isVolatileQualified(), "tmp");
505      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
506                                        Dst.getVectorIdx(), "vecins");
507      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
508      return;
509    }
510
511    // If this is an update of extended vector elements, insert them as
512    // appropriate.
513    if (Dst.isExtVectorElt())
514      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
515
516    if (Dst.isBitfield())
517      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
518
519    if (Dst.isPropertyRef())
520      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
521
522    assert(Dst.isKVCRef() && "Unknown LValue type");
523    return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
524  }
525
526  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
527    // load of a __weak object.
528    llvm::Value *LvalueDst = Dst.getAddress();
529    llvm::Value *src = Src.getScalarVal();
530     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
531    return;
532  }
533
534  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
535    // load of a __strong object.
536    llvm::Value *LvalueDst = Dst.getAddress();
537    llvm::Value *src = Src.getScalarVal();
538    if (Dst.isObjCIvar()) {
539      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
540      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
541      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
542      llvm::Value *dst = RHS;
543      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
544      llvm::Value *LHS =
545        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
546      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
547      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
548                                              BytesBetween);
549    } else if (Dst.isGlobalObjCRef())
550      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
551    else
552      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
553    return;
554  }
555
556  assert(Src.isScalar() && "Can't emit an agg store with this method");
557  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
558                    Dst.isVolatileQualified(), Ty);
559}
560
561void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
562                                                     QualType Ty,
563                                                     llvm::Value **Result) {
564  unsigned StartBit = Dst.getBitfieldStartBit();
565  unsigned BitfieldSize = Dst.getBitfieldSize();
566  llvm::Value *Ptr = Dst.getBitfieldAddr();
567
568  const llvm::Type *EltTy =
569    cast<llvm::PointerType>(Ptr->getType())->getElementType();
570  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
571
572  // Get the new value, cast to the appropriate type and masked to exactly the
573  // size of the bit-field.
574  llvm::Value *SrcVal = Src.getScalarVal();
575  llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp");
576  llvm::Constant *Mask = llvm::ConstantInt::get(VMContext,
577                           llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize));
578  NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value");
579
580  // Return the new value of the bit-field, if requested.
581  if (Result) {
582    // Cast back to the proper type for result.
583    const llvm::Type *SrcTy = SrcVal->getType();
584    llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false,
585                                                  "bf.reload.val");
586
587    // Sign extend if necessary.
588    if (Dst.isBitfieldSigned()) {
589      unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy);
590      llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy,
591                                                      SrcTySize - BitfieldSize);
592      SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits),
593                                    ExtraBits, "bf.reload.sext");
594    }
595
596    *Result = SrcTrunc;
597  }
598
599  // In some cases the bitfield may straddle two memory locations.  Emit the low
600  // part first and check to see if the high needs to be done.
601  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
602  llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(),
603                                           "bf.prev.low");
604
605  // Compute the mask for zero-ing the low part of this bitfield.
606  llvm::Constant *InvMask =
607    llvm::ConstantInt::get(VMContext,
608             ~llvm::APInt::getBitsSet(EltTySize, StartBit, StartBit + LowBits));
609
610  // Compute the new low part as
611  //   LowVal = (LowVal & InvMask) | (NewVal << StartBit),
612  // with the shift of NewVal implicitly stripping the high bits.
613  llvm::Value *NewLowVal =
614    Builder.CreateShl(NewVal, StartBit, "bf.value.lo");
615  LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared");
616  LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo");
617
618  // Write back.
619  Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified());
620
621  // If the low part doesn't cover the bitfield emit a high part.
622  if (LowBits < BitfieldSize) {
623    unsigned HighBits = BitfieldSize - LowBits;
624    llvm::Value *HighPtr =  Builder.CreateGEP(Ptr, llvm::ConstantInt::get(
625                            llvm::Type::getInt32Ty(VMContext), 1), "bf.ptr.hi");
626    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
627                                              Dst.isVolatileQualified(),
628                                              "bf.prev.hi");
629
630    // Compute the mask for zero-ing the high part of this bitfield.
631    llvm::Constant *InvMask =
632      llvm::ConstantInt::get(VMContext, ~llvm::APInt::getLowBitsSet(EltTySize,
633                               HighBits));
634
635    // Compute the new high part as
636    //   HighVal = (HighVal & InvMask) | (NewVal lshr LowBits),
637    // where the high bits of NewVal have already been cleared and the
638    // shift stripping the low bits.
639    llvm::Value *NewHighVal =
640      Builder.CreateLShr(NewVal, LowBits, "bf.value.high");
641    HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared");
642    HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi");
643
644    // Write back.
645    Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified());
646  }
647}
648
649void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
650                                                        LValue Dst,
651                                                        QualType Ty) {
652  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
653}
654
655void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
656                                                   LValue Dst,
657                                                   QualType Ty) {
658  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
659}
660
661void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
662                                                               LValue Dst,
663                                                               QualType Ty) {
664  // This access turns into a read/modify/write of the vector.  Load the input
665  // value now.
666  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
667                                        Dst.isVolatileQualified(), "tmp");
668  const llvm::Constant *Elts = Dst.getExtVectorElts();
669
670  llvm::Value *SrcVal = Src.getScalarVal();
671
672  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
673    unsigned NumSrcElts = VTy->getNumElements();
674    unsigned NumDstElts =
675       cast<llvm::VectorType>(Vec->getType())->getNumElements();
676    if (NumDstElts == NumSrcElts) {
677      // Use shuffle vector is the src and destination are the same number of
678      // elements and restore the vector mask since it is on the side it will be
679      // stored.
680      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
681      for (unsigned i = 0; i != NumSrcElts; ++i) {
682        unsigned InIdx = getAccessedFieldNo(i, Elts);
683        Mask[InIdx] = llvm::ConstantInt::get(
684                                          llvm::Type::getInt32Ty(VMContext), i);
685      }
686
687      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
688      Vec = Builder.CreateShuffleVector(SrcVal,
689                                        llvm::UndefValue::get(Vec->getType()),
690                                        MaskV, "tmp");
691    } else if (NumDstElts > NumSrcElts) {
692      // Extended the source vector to the same length and then shuffle it
693      // into the destination.
694      // FIXME: since we're shuffling with undef, can we just use the indices
695      //        into that?  This could be simpler.
696      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
697      const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
698      unsigned i;
699      for (i = 0; i != NumSrcElts; ++i)
700        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
701      for (; i != NumDstElts; ++i)
702        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
703      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
704                                                        ExtMask.size());
705      llvm::Value *ExtSrcVal =
706        Builder.CreateShuffleVector(SrcVal,
707                                    llvm::UndefValue::get(SrcVal->getType()),
708                                    ExtMaskV, "tmp");
709      // build identity
710      llvm::SmallVector<llvm::Constant*, 4> Mask;
711      for (unsigned i = 0; i != NumDstElts; ++i)
712        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
713
714      // modify when what gets shuffled in
715      for (unsigned i = 0; i != NumSrcElts; ++i) {
716        unsigned Idx = getAccessedFieldNo(i, Elts);
717        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
718      }
719      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
720      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
721    } else {
722      // We should never shorten the vector
723      assert(0 && "unexpected shorten vector length");
724    }
725  } else {
726    // If the Src is a scalar (not a vector) it must be updating one element.
727    unsigned InIdx = getAccessedFieldNo(0, Elts);
728    const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
729    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
730    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
731  }
732
733  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
734}
735
736// setObjCGCLValueClass - sets class of he lvalue for the purpose of
737// generating write-barries API. It is currently a global, ivar,
738// or neither.
739static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
740                                 LValue &LV) {
741  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
742    return;
743
744  if (isa<ObjCIvarRefExpr>(E)) {
745    LV.SetObjCIvar(LV, true);
746    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
747    LV.setBaseIvarExp(Exp->getBase());
748    LV.SetObjCArray(LV, E->getType()->isArrayType());
749    return;
750  }
751
752  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
753    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
754      if ((VD->isBlockVarDecl() && !VD->hasLocalStorage()) ||
755          VD->isFileVarDecl())
756        LV.SetGlobalObjCRef(LV, true);
757    }
758    LV.SetObjCArray(LV, E->getType()->isArrayType());
759    return;
760  }
761
762  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
763    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
764    return;
765  }
766
767  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
768    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
769    if (LV.isObjCIvar()) {
770      // If cast is to a structure pointer, follow gcc's behavior and make it
771      // a non-ivar write-barrier.
772      QualType ExpTy = E->getType();
773      if (ExpTy->isPointerType())
774        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
775      if (ExpTy->isRecordType())
776        LV.SetObjCIvar(LV, false);
777    }
778    return;
779  }
780  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
781    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
782    return;
783  }
784
785  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
786    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
787    return;
788  }
789
790  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
791    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
792    if (LV.isObjCIvar() && !LV.isObjCArray())
793      // Using array syntax to assigning to what an ivar points to is not
794      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
795      LV.SetObjCIvar(LV, false);
796    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
797      // Using array syntax to assigning to what global points to is not
798      // same as assigning to the global itself. {id *G;} G[i] = 0;
799      LV.SetGlobalObjCRef(LV, false);
800    return;
801  }
802
803  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
804    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
805    // We don't know if member is an 'ivar', but this flag is looked at
806    // only in the context of LV.isObjCIvar().
807    LV.SetObjCArray(LV, E->getType()->isArrayType());
808    return;
809  }
810}
811
812static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
813                                      const Expr *E, const VarDecl *VD) {
814  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
815         "Var decl must have external storage or be a file var decl!");
816
817  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
818  if (VD->getType()->isReferenceType())
819    V = CGF.Builder.CreateLoad(V, "tmp");
820  LValue LV = LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
821  setObjCGCLValueClass(CGF.getContext(), E, LV);
822  return LV;
823}
824
825static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
826                                      const Expr *E, const FunctionDecl *FD) {
827  llvm::Value* V = CGF.CGM.GetAddrOfFunction(FD);
828  if (!FD->hasPrototype()) {
829    if (const FunctionProtoType *Proto =
830            FD->getType()->getAs<FunctionProtoType>()) {
831      // Ugly case: for a K&R-style definition, the type of the definition
832      // isn't the same as the type of a use.  Correct for this with a
833      // bitcast.
834      QualType NoProtoType =
835          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
836      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
837      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
838    }
839  }
840  return LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
841}
842
843LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
844  const NamedDecl *ND = E->getDecl();
845
846  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
847
848    // Check if this is a global variable.
849    if (VD->hasExternalStorage() || VD->isFileVarDecl())
850      return EmitGlobalVarDeclLValue(*this, E, VD);
851
852    bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
853
854    llvm::Value *V = LocalDeclMap[VD];
855    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
856
857    Qualifiers Quals = MakeQualifiers(E->getType());
858    // local variables do not get their gc attribute set.
859    // local static?
860    if (NonGCable) Quals.removeObjCGCAttr();
861
862    if (VD->hasAttr<BlocksAttr>()) {
863      V = Builder.CreateStructGEP(V, 1, "forwarding");
864      V = Builder.CreateLoad(V);
865      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
866                                  VD->getNameAsString());
867    }
868    if (VD->getType()->isReferenceType())
869      V = Builder.CreateLoad(V, "tmp");
870    LValue LV = LValue::MakeAddr(V, Quals);
871    LValue::SetObjCNonGC(LV, NonGCable);
872    setObjCGCLValueClass(getContext(), E, LV);
873    return LV;
874  }
875
876  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
877    return EmitFunctionDeclLValue(*this, E, FD);
878
879  if (E->getQualifier()) {
880    // FIXME: the qualifier check does not seem sufficient here
881    return EmitPointerToDataMemberLValue(cast<FieldDecl>(ND));
882  }
883
884  assert(false && "Unhandled DeclRefExpr");
885
886  // an invalid LValue, but the assert will
887  // ensure that this point is never reached.
888  return LValue();
889}
890
891LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
892  return LValue::MakeAddr(GetAddrOfBlockDecl(E), MakeQualifiers(E->getType()));
893}
894
895LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
896  // __extension__ doesn't affect lvalue-ness.
897  if (E->getOpcode() == UnaryOperator::Extension)
898    return EmitLValue(E->getSubExpr());
899
900  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
901  switch (E->getOpcode()) {
902  default: assert(0 && "Unknown unary operator lvalue!");
903  case UnaryOperator::Deref: {
904    QualType T = E->getSubExpr()->getType()->getPointeeType();
905    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
906
907    Qualifiers Quals = MakeQualifiers(T);
908    Quals.setAddressSpace(ExprTy.getAddressSpace());
909
910    LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), Quals);
911    // We should not generate __weak write barrier on indirect reference
912    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
913    // But, we continue to generate __strong write barrier on indirect write
914    // into a pointer to object.
915    if (getContext().getLangOptions().ObjC1 &&
916        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
917        LV.isObjCWeak())
918      LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
919    return LV;
920  }
921  case UnaryOperator::Real:
922  case UnaryOperator::Imag: {
923    LValue LV = EmitLValue(E->getSubExpr());
924    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
925    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
926                                                    Idx, "idx"),
927                            MakeQualifiers(ExprTy));
928  }
929  case UnaryOperator::PreInc:
930  case UnaryOperator::PreDec:
931    return EmitUnsupportedLValue(E, "pre-inc/dec expression");
932  }
933}
934
935LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
936  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E),
937                          Qualifiers());
938}
939
940LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
941  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E),
942                          Qualifiers());
943}
944
945
946LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
947  std::string GlobalVarName;
948
949  switch (Type) {
950  default: assert(0 && "Invalid type");
951  case PredefinedExpr::Func:
952    GlobalVarName = "__func__.";
953    break;
954  case PredefinedExpr::Function:
955    GlobalVarName = "__FUNCTION__.";
956    break;
957  case PredefinedExpr::PrettyFunction:
958    GlobalVarName = "__PRETTY_FUNCTION__.";
959    break;
960  }
961
962  llvm::StringRef FnName = CurFn->getName();
963  if (FnName.startswith("\01"))
964    FnName = FnName.substr(1);
965  GlobalVarName += FnName;
966
967  std::string FunctionName =
968    PredefinedExpr::ComputeName(getContext(), (PredefinedExpr::IdentType)Type,
969                                CurCodeDecl);
970
971  llvm::Constant *C =
972    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
973  return LValue::MakeAddr(C, Qualifiers());
974}
975
976LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
977  switch (E->getIdentType()) {
978  default:
979    return EmitUnsupportedLValue(E, "predefined expression");
980  case PredefinedExpr::Func:
981  case PredefinedExpr::Function:
982  case PredefinedExpr::PrettyFunction:
983    return EmitPredefinedFunctionName(E->getIdentType());
984  }
985}
986
987LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
988  // The index must always be an integer, which is not an aggregate.  Emit it.
989  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
990  QualType IdxTy  = E->getIdx()->getType();
991  bool IdxSigned = IdxTy->isSignedIntegerType();
992
993  // If the base is a vector type, then we are forming a vector element lvalue
994  // with this subscript.
995  if (E->getBase()->getType()->isVectorType()) {
996    // Emit the vector as an lvalue to get its address.
997    LValue LHS = EmitLValue(E->getBase());
998    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
999    Idx = Builder.CreateIntCast(Idx,
1000                          llvm::Type::getInt32Ty(VMContext), IdxSigned, "vidx");
1001    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1002                                 E->getBase()->getType().getCVRQualifiers());
1003  }
1004
1005  // The base must be a pointer, which is not an aggregate.  Emit it.
1006  llvm::Value *Base = EmitScalarExpr(E->getBase());
1007
1008  // Extend or truncate the index type to 32 or 64-bits.
1009  unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
1010  if (IdxBitwidth != LLVMPointerWidth)
1011    Idx = Builder.CreateIntCast(Idx,
1012                            llvm::IntegerType::get(VMContext, LLVMPointerWidth),
1013                                IdxSigned, "idxprom");
1014
1015  // We know that the pointer points to a type of the correct size, unless the
1016  // size is a VLA or Objective-C interface.
1017  llvm::Value *Address = 0;
1018  if (const VariableArrayType *VAT =
1019        getContext().getAsVariableArrayType(E->getType())) {
1020    llvm::Value *VLASize = GetVLASize(VAT);
1021
1022    Idx = Builder.CreateMul(Idx, VLASize);
1023
1024    QualType BaseType = getContext().getBaseElementType(VAT);
1025
1026    uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
1027    Idx = Builder.CreateUDiv(Idx,
1028                             llvm::ConstantInt::get(Idx->getType(),
1029                                                    BaseTypeSize));
1030    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1031  } else if (const ObjCInterfaceType *OIT =
1032             dyn_cast<ObjCInterfaceType>(E->getType())) {
1033    llvm::Value *InterfaceSize =
1034      llvm::ConstantInt::get(Idx->getType(),
1035                             getContext().getTypeSize(OIT) / 8);
1036
1037    Idx = Builder.CreateMul(Idx, InterfaceSize);
1038
1039    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1040    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1041                                Idx, "arrayidx");
1042    Address = Builder.CreateBitCast(Address, Base->getType());
1043  } else {
1044    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1045  }
1046
1047  QualType T = E->getBase()->getType()->getPointeeType();
1048  assert(!T.isNull() &&
1049         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1050
1051  Qualifiers Quals = MakeQualifiers(T);
1052  Quals.setAddressSpace(E->getBase()->getType().getAddressSpace());
1053
1054  LValue LV = LValue::MakeAddr(Address, Quals);
1055  if (getContext().getLangOptions().ObjC1 &&
1056      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1057    LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1058    setObjCGCLValueClass(getContext(), E, LV);
1059  }
1060  return LV;
1061}
1062
1063static
1064llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1065                                       llvm::SmallVector<unsigned, 4> &Elts) {
1066  llvm::SmallVector<llvm::Constant *, 4> CElts;
1067
1068  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1069    CElts.push_back(llvm::ConstantInt::get(
1070                                   llvm::Type::getInt32Ty(VMContext), Elts[i]));
1071
1072  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1073}
1074
1075LValue CodeGenFunction::
1076EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1077  // Emit the base vector as an l-value.
1078  LValue Base;
1079
1080  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1081  if (!E->isArrow()) {
1082    assert(E->getBase()->getType()->isVectorType());
1083    Base = EmitLValue(E->getBase());
1084  } else {
1085    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1086    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1087    Qualifiers Quals = MakeQualifiers(PT->getPointeeType());
1088    Quals.removeObjCGCAttr();
1089    Base = LValue::MakeAddr(Ptr, Quals);
1090  }
1091
1092  // Encode the element access list into a vector of unsigned indices.
1093  llvm::SmallVector<unsigned, 4> Indices;
1094  E->getEncodedElementAccess(Indices);
1095
1096  if (Base.isSimple()) {
1097    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1098    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1099                                    Base.getVRQualifiers());
1100  }
1101  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1102
1103  llvm::Constant *BaseElts = Base.getExtVectorElts();
1104  llvm::SmallVector<llvm::Constant *, 4> CElts;
1105
1106  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1107  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1108    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1109      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1110    else
1111      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1112  }
1113  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1114  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1115                                  Base.getVRQualifiers());
1116}
1117
1118LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1119  bool isUnion = false;
1120  bool isNonGC = false;
1121  Expr *BaseExpr = E->getBase();
1122  llvm::Value *BaseValue = NULL;
1123  Qualifiers BaseQuals;
1124
1125  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1126  if (E->isArrow()) {
1127    BaseValue = EmitScalarExpr(BaseExpr);
1128    const PointerType *PTy =
1129      BaseExpr->getType()->getAs<PointerType>();
1130    if (PTy->getPointeeType()->isUnionType())
1131      isUnion = true;
1132    BaseQuals = PTy->getPointeeType().getQualifiers();
1133  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1134             isa<ObjCImplicitSetterGetterRefExpr>(
1135               BaseExpr->IgnoreParens())) {
1136    RValue RV = EmitObjCPropertyGet(BaseExpr);
1137    BaseValue = RV.getAggregateAddr();
1138    if (BaseExpr->getType()->isUnionType())
1139      isUnion = true;
1140    BaseQuals = BaseExpr->getType().getQualifiers();
1141  } else {
1142    LValue BaseLV = EmitLValue(BaseExpr);
1143    if (BaseLV.isNonGC())
1144      isNonGC = true;
1145    // FIXME: this isn't right for bitfields.
1146    BaseValue = BaseLV.getAddress();
1147    QualType BaseTy = BaseExpr->getType();
1148    if (BaseTy->isUnionType())
1149      isUnion = true;
1150    BaseQuals = BaseTy.getQualifiers();
1151  }
1152
1153  NamedDecl *ND = E->getMemberDecl();
1154  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1155    LValue LV = EmitLValueForField(BaseValue, Field, isUnion,
1156                                   BaseQuals.getCVRQualifiers());
1157    LValue::SetObjCNonGC(LV, isNonGC);
1158    setObjCGCLValueClass(getContext(), E, LV);
1159    return LV;
1160  }
1161
1162  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1163    return EmitGlobalVarDeclLValue(*this, E, VD);
1164
1165  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1166    return EmitFunctionDeclLValue(*this, E, FD);
1167
1168  assert(false && "Unhandled member declaration!");
1169  return LValue();
1170}
1171
1172LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
1173                                              const FieldDecl* Field,
1174                                              unsigned CVRQualifiers) {
1175  CodeGenTypes::BitFieldInfo Info = CGM.getTypes().getBitFieldInfo(Field);
1176
1177  // FIXME: CodeGenTypes should expose a method to get the appropriate type for
1178  // FieldTy (the appropriate type is ABI-dependent).
1179  const llvm::Type *FieldTy =
1180    CGM.getTypes().ConvertTypeForMem(Field->getType());
1181  const llvm::PointerType *BaseTy =
1182  cast<llvm::PointerType>(BaseValue->getType());
1183  unsigned AS = BaseTy->getAddressSpace();
1184  BaseValue = Builder.CreateBitCast(BaseValue,
1185                                    llvm::PointerType::get(FieldTy, AS),
1186                                    "tmp");
1187
1188  llvm::Value *Idx =
1189    llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Info.FieldNo);
1190  llvm::Value *V = Builder.CreateGEP(BaseValue, Idx, "tmp");
1191
1192  return LValue::MakeBitfield(V, Info.Start, Info.Size,
1193                              Field->getType()->isSignedIntegerType(),
1194                            Field->getType().getCVRQualifiers()|CVRQualifiers);
1195}
1196
1197LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
1198                                           const FieldDecl* Field,
1199                                           bool isUnion,
1200                                           unsigned CVRQualifiers) {
1201  if (Field->isBitField())
1202    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1203
1204  unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
1205  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1206
1207  // Match union field type.
1208  if (isUnion) {
1209    const llvm::Type *FieldTy =
1210      CGM.getTypes().ConvertTypeForMem(Field->getType());
1211    const llvm::PointerType * BaseTy =
1212      cast<llvm::PointerType>(BaseValue->getType());
1213    unsigned AS = BaseTy->getAddressSpace();
1214    V = Builder.CreateBitCast(V,
1215                              llvm::PointerType::get(FieldTy, AS),
1216                              "tmp");
1217  }
1218  if (Field->getType()->isReferenceType())
1219    V = Builder.CreateLoad(V, "tmp");
1220
1221  Qualifiers Quals = MakeQualifiers(Field->getType());
1222  Quals.addCVRQualifiers(CVRQualifiers);
1223  // __weak attribute on a field is ignored.
1224  if (Quals.getObjCGCAttr() == Qualifiers::Weak)
1225    Quals.removeObjCGCAttr();
1226
1227  return LValue::MakeAddr(V, Quals);
1228}
1229
1230LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
1231  const llvm::Type *LTy = ConvertType(E->getType());
1232  llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral");
1233
1234  const Expr* InitExpr = E->getInitializer();
1235  LValue Result = LValue::MakeAddr(DeclPtr, MakeQualifiers(E->getType()));
1236
1237  if (E->getType()->isComplexType())
1238    EmitComplexExprIntoAddr(InitExpr, DeclPtr, false);
1239  else if (hasAggregateLLVMType(E->getType()))
1240    EmitAnyExpr(InitExpr, DeclPtr, false);
1241  else
1242    EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType());
1243
1244  return Result;
1245}
1246
1247LValue
1248CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
1249  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1250    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1251    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1252    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1253
1254    llvm::Value *Cond = EvaluateExprAsBool(E->getCond());
1255    Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
1256
1257    EmitBlock(LHSBlock);
1258
1259    LValue LHS = EmitLValue(E->getLHS());
1260    if (!LHS.isSimple())
1261      return EmitUnsupportedLValue(E, "conditional operator");
1262
1263    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1264    Builder.CreateStore(LHS.getAddress(), Temp);
1265    EmitBranch(ContBlock);
1266
1267    EmitBlock(RHSBlock);
1268    LValue RHS = EmitLValue(E->getRHS());
1269    if (!RHS.isSimple())
1270      return EmitUnsupportedLValue(E, "conditional operator");
1271
1272    Builder.CreateStore(RHS.getAddress(), Temp);
1273    EmitBranch(ContBlock);
1274
1275    EmitBlock(ContBlock);
1276
1277    Temp = Builder.CreateLoad(Temp, "lv");
1278    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1279  }
1280
1281  // ?: here should be an aggregate.
1282  assert((hasAggregateLLVMType(E->getType()) &&
1283          !E->getType()->isAnyComplexType()) &&
1284         "Unexpected conditional operator!");
1285
1286  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1287  EmitAggExpr(E, Temp, false);
1288
1289  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1290}
1291
1292/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1293/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1294/// otherwise if a cast is needed by the code generator in an lvalue context,
1295/// then it must mean that we need the address of an aggregate in order to
1296/// access one of its fields.  This can happen for all the reasons that casts
1297/// are permitted with aggregate result, including noop aggregate casts, and
1298/// cast from scalar to union.
1299LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1300  switch (E->getCastKind()) {
1301  default:
1302    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1303
1304  case CastExpr::CK_Dynamic: {
1305    LValue LV = EmitLValue(E->getSubExpr());
1306    llvm::Value *V = LV.getAddress();
1307    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1308    return LValue::MakeAddr(EmitDynamicCast(V, DCE),
1309                            MakeQualifiers(E->getType()));
1310  }
1311
1312  case CastExpr::CK_NoOp:
1313  case CastExpr::CK_ConstructorConversion:
1314  case CastExpr::CK_UserDefinedConversion:
1315    return EmitLValue(E->getSubExpr());
1316
1317  case CastExpr::CK_DerivedToBase: {
1318    const RecordType *DerivedClassTy =
1319      E->getSubExpr()->getType()->getAs<RecordType>();
1320    CXXRecordDecl *DerivedClassDecl =
1321      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1322
1323    const RecordType *BaseClassTy = E->getType()->getAs<RecordType>();
1324    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl());
1325
1326    LValue LV = EmitLValue(E->getSubExpr());
1327
1328    // Perform the derived-to-base conversion
1329    llvm::Value *Base =
1330      GetAddressOfBaseClass(LV.getAddress(), DerivedClassDecl,
1331                            BaseClassDecl, /*NullCheckValue=*/false);
1332
1333    return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
1334  }
1335  case CastExpr::CK_ToUnion: {
1336    llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1337    EmitAnyExpr(E->getSubExpr(), Temp, false);
1338
1339    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1340  }
1341  case CastExpr::CK_BaseToDerived: {
1342    const RecordType *BaseClassTy =
1343      E->getSubExpr()->getType()->getAs<RecordType>();
1344    CXXRecordDecl *BaseClassDecl =
1345      cast<CXXRecordDecl>(BaseClassTy->getDecl());
1346
1347    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1348    CXXRecordDecl *DerivedClassDecl =
1349      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1350
1351    LValue LV = EmitLValue(E->getSubExpr());
1352
1353    // Perform the base-to-derived conversion
1354    llvm::Value *Derived =
1355      GetAddressOfDerivedClass(LV.getAddress(), BaseClassDecl,
1356                               DerivedClassDecl, /*NullCheckValue=*/false);
1357
1358    return LValue::MakeAddr(Derived, MakeQualifiers(E->getType()));
1359  }
1360  case CastExpr::CK_BitCast: {
1361    // This must be a reinterpret_cast (or c-style equivalent).
1362    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1363
1364    LValue LV = EmitLValue(E->getSubExpr());
1365    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1366                                           ConvertType(CE->getTypeAsWritten()));
1367    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1368  }
1369  }
1370}
1371
1372LValue CodeGenFunction::EmitNullInitializationLValue(
1373                                              const CXXZeroInitValueExpr *E) {
1374  QualType Ty = E->getType();
1375  const llvm::Type *LTy = ConvertTypeForMem(Ty);
1376  llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
1377  unsigned Align = getContext().getTypeAlign(Ty)/8;
1378  Alloc->setAlignment(Align);
1379  LValue lvalue = LValue::MakeAddr(Alloc, Qualifiers());
1380  EmitMemSetToZero(lvalue.getAddress(), Ty);
1381  return lvalue;
1382}
1383
1384//===--------------------------------------------------------------------===//
1385//                             Expression Emission
1386//===--------------------------------------------------------------------===//
1387
1388
1389RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
1390  // Builtins never have block type.
1391  if (E->getCallee()->getType()->isBlockPointerType())
1392    return EmitBlockCallExpr(E);
1393
1394  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1395    return EmitCXXMemberCallExpr(CE);
1396
1397  const Decl *TargetDecl = 0;
1398  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1399    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1400      TargetDecl = DRE->getDecl();
1401      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1402        if (unsigned builtinID = FD->getBuiltinID())
1403          return EmitBuiltinExpr(FD, builtinID, E);
1404    }
1405  }
1406
1407  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1408    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1409      return EmitCXXOperatorMemberCallExpr(CE, MD);
1410
1411  if (isa<CXXPseudoDestructorExpr>(E->getCallee())) {
1412    // C++ [expr.pseudo]p1:
1413    //   The result shall only be used as the operand for the function call
1414    //   operator (), and the result of such a call has type void. The only
1415    //   effect is the evaluation of the postfix-expression before the dot or
1416    //   arrow.
1417    EmitScalarExpr(E->getCallee());
1418    return RValue::get(0);
1419  }
1420
1421  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1422  return EmitCall(Callee, E->getCallee()->getType(),
1423                  E->arg_begin(), E->arg_end(), TargetDecl);
1424}
1425
1426LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1427  // Comma expressions just emit their LHS then their RHS as an l-value.
1428  if (E->getOpcode() == BinaryOperator::Comma) {
1429    EmitAnyExpr(E->getLHS());
1430    EnsureInsertPoint();
1431    return EmitLValue(E->getRHS());
1432  }
1433
1434  if (E->getOpcode() == BinaryOperator::PtrMemD ||
1435      E->getOpcode() == BinaryOperator::PtrMemI)
1436    return EmitPointerToDataMemberBinaryExpr(E);
1437
1438  // Can only get l-value for binary operator expressions which are a
1439  // simple assignment of aggregate type.
1440  if (E->getOpcode() != BinaryOperator::Assign)
1441    return EmitUnsupportedLValue(E, "binary l-value expression");
1442
1443  if (!hasAggregateLLVMType(E->getType())) {
1444    // Emit the LHS as an l-value.
1445    LValue LV = EmitLValue(E->getLHS());
1446
1447    llvm::Value *RHS = EmitScalarExpr(E->getRHS());
1448    EmitStoreOfScalar(RHS, LV.getAddress(), LV.isVolatileQualified(),
1449                      E->getType());
1450    return LV;
1451  }
1452
1453  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1454  EmitAggExpr(E, Temp, false);
1455  // FIXME: Are these qualifiers correct?
1456  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1457}
1458
1459LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
1460  RValue RV = EmitCallExpr(E);
1461
1462  if (!RV.isScalar())
1463    return LValue::MakeAddr(RV.getAggregateAddr(),MakeQualifiers(E->getType()));
1464
1465  assert(E->getCallReturnType()->isReferenceType() &&
1466         "Can't have a scalar return unless the return type is a "
1467         "reference type!");
1468
1469  return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
1470}
1471
1472LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
1473  // FIXME: This shouldn't require another copy.
1474  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1475  EmitAggExpr(E, Temp, false);
1476  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1477}
1478
1479LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
1480  llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), "tmp");
1481  EmitCXXConstructExpr(Temp, E);
1482  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1483}
1484
1485LValue
1486CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
1487  llvm::Value *Temp = EmitCXXTypeidExpr(E);
1488  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1489}
1490
1491LValue
1492CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
1493  LValue LV = EmitLValue(E->getSubExpr());
1494  PushCXXTemporary(E->getTemporary(), LV.getAddress());
1495  return LV;
1496}
1497
1498LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
1499  // Can only get l-value for message expression returning aggregate type
1500  RValue RV = EmitObjCMessageExpr(E);
1501  // FIXME: can this be volatile?
1502  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1503}
1504
1505llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
1506                                             const ObjCIvarDecl *Ivar) {
1507  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
1508}
1509
1510LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
1511                                          llvm::Value *BaseValue,
1512                                          const ObjCIvarDecl *Ivar,
1513                                          unsigned CVRQualifiers) {
1514  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
1515                                                   Ivar, CVRQualifiers);
1516}
1517
1518LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
1519  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
1520  llvm::Value *BaseValue = 0;
1521  const Expr *BaseExpr = E->getBase();
1522  Qualifiers BaseQuals;
1523  QualType ObjectTy;
1524  if (E->isArrow()) {
1525    BaseValue = EmitScalarExpr(BaseExpr);
1526    ObjectTy = BaseExpr->getType()->getPointeeType();
1527    BaseQuals = ObjectTy.getQualifiers();
1528  } else {
1529    LValue BaseLV = EmitLValue(BaseExpr);
1530    // FIXME: this isn't right for bitfields.
1531    BaseValue = BaseLV.getAddress();
1532    ObjectTy = BaseExpr->getType();
1533    BaseQuals = ObjectTy.getQualifiers();
1534  }
1535
1536  LValue LV =
1537    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
1538                      BaseQuals.getCVRQualifiers());
1539  setObjCGCLValueClass(getContext(), E, LV);
1540  return LV;
1541}
1542
1543LValue
1544CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
1545  // This is a special l-value that just issues sends when we load or store
1546  // through it.
1547  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
1548}
1549
1550LValue CodeGenFunction::EmitObjCKVCRefLValue(
1551                                const ObjCImplicitSetterGetterRefExpr *E) {
1552  // This is a special l-value that just issues sends when we load or store
1553  // through it.
1554  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
1555}
1556
1557LValue CodeGenFunction::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
1558  return EmitUnsupportedLValue(E, "use of super");
1559}
1560
1561LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
1562  // Can only get l-value for message expression returning aggregate type
1563  RValue RV = EmitAnyExprToTemp(E);
1564  // FIXME: can this be volatile?
1565  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1566}
1567
1568
1569LValue CodeGenFunction::EmitPointerToDataMemberLValue(const FieldDecl *Field) {
1570  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Field->getDeclContext());
1571  QualType NNSpecTy =
1572    getContext().getCanonicalType(
1573      getContext().getTypeDeclType(const_cast<CXXRecordDecl*>(ClassDecl)));
1574  NNSpecTy = getContext().getPointerType(NNSpecTy);
1575  llvm::Value *V = llvm::Constant::getNullValue(ConvertType(NNSpecTy));
1576  LValue MemExpLV = EmitLValueForField(V, Field, /*isUnion=*/false,
1577                                       /*Qualifiers=*/0);
1578  const llvm::Type *ResultType = ConvertType(getContext().getPointerDiffType());
1579  V = Builder.CreatePtrToInt(MemExpLV.getAddress(), ResultType, "datamember");
1580  return LValue::MakeAddr(V, MakeQualifiers(Field->getType()));
1581}
1582
1583RValue CodeGenFunction::EmitCall(llvm::Value *Callee, QualType CalleeType,
1584                                 CallExpr::const_arg_iterator ArgBeg,
1585                                 CallExpr::const_arg_iterator ArgEnd,
1586                                 const Decl *TargetDecl) {
1587  // Get the actual function type. The callee type will always be a pointer to
1588  // function type or a block pointer type.
1589  assert(CalleeType->isFunctionPointerType() &&
1590         "Call must have function pointer type!");
1591
1592  CalleeType = getContext().getCanonicalType(CalleeType);
1593
1594  QualType FnType = cast<PointerType>(CalleeType)->getPointeeType();
1595  QualType ResultType = cast<FunctionType>(FnType)->getResultType();
1596
1597  CallArgList Args;
1598  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
1599
1600  // FIXME: We should not need to do this, it should be part of the function
1601  // type.
1602  unsigned CallingConvention = 0;
1603  if (const llvm::Function *F =
1604      dyn_cast<llvm::Function>(Callee->stripPointerCasts()))
1605    CallingConvention = F->getCallingConv();
1606  return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args,
1607                                                 CallingConvention),
1608                  Callee, Args, TargetDecl);
1609}
1610
1611LValue CodeGenFunction::
1612EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
1613  llvm::Value *BaseV;
1614  if (E->getOpcode() == BinaryOperator::PtrMemI)
1615    BaseV = EmitScalarExpr(E->getLHS());
1616  else
1617    BaseV = EmitLValue(E->getLHS()).getAddress();
1618  const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
1619  BaseV = Builder.CreateBitCast(BaseV, i8Ty);
1620  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
1621  llvm::Value *AddV = Builder.CreateInBoundsGEP(BaseV, OffsetV, "add.ptr");
1622
1623  QualType Ty = E->getRHS()->getType();
1624  Ty = Ty->getAs<MemberPointerType>()->getPointeeType();
1625
1626  const llvm::Type *PType = ConvertType(getContext().getPointerType(Ty));
1627  AddV = Builder.CreateBitCast(AddV, PType);
1628  return LValue::MakeAddr(AddV, MakeQualifiers(Ty));
1629}
1630
1631