CGExpr.cpp revision 00a1ad9a34f1006d8729aa3fab4fb5f233ab5a55 
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    if (ShouldDestroyTemporaries) {
88      // Keep track of the current cleanup stack depth.
89      OldNumLiveTemporaries = LiveTemporaries.size();
90    }
91
92    E = TE->getSubExpr();
93  }
94
95  RValue Val;
96  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
97    // Emit the expr as an lvalue.
98    LValue LV = EmitLValue(E);
99    if (LV.isSimple())
100      return RValue::get(LV.getAddress());
101    Val = EmitLoadOfLValue(LV, E->getType());
102
103    if (ShouldDestroyTemporaries) {
104      // Pop temporaries.
105      while (LiveTemporaries.size() > OldNumLiveTemporaries)
106        PopCXXTemporary();
107    }
108  } else {
109    const CXXRecordDecl *BaseClassDecl = 0;
110    const CXXRecordDecl *DerivedClassDecl = 0;
111
112    if (const CastExpr *CE =
113          dyn_cast<CastExpr>(E->IgnoreParenNoopCasts(getContext()))) {
114      if (CE->getCastKind() == CastExpr::CK_DerivedToBase) {
115        E = CE->getSubExpr();
116
117        BaseClassDecl =
118          cast<CXXRecordDecl>(CE->getType()->getAs<RecordType>()->getDecl());
119        DerivedClassDecl =
120          cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
121      }
122    }
123
124    Val = EmitAnyExprToTemp(E, /*IsAggLocVolatile=*/false,
125                            IsInitializer);
126
127    if (ShouldDestroyTemporaries) {
128      // Pop temporaries.
129      while (LiveTemporaries.size() > OldNumLiveTemporaries)
130        PopCXXTemporary();
131    }
132
133    if (IsInitializer) {
134      // We might have to destroy the temporary variable.
135      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
136        if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
137          if (!ClassDecl->hasTrivialDestructor()) {
138            const CXXDestructorDecl *Dtor =
139              ClassDecl->getDestructor(getContext());
140
141            CleanupScope scope(*this);
142            EmitCXXDestructorCall(Dtor, Dtor_Complete, Val.getAggregateAddr());
143          }
144        }
145      }
146    }
147
148    // Check if need to perform the derived-to-base cast.
149    if (BaseClassDecl) {
150      llvm::Value *Derived = Val.getAggregateAddr();
151
152      llvm::Value *Base =
153        GetAddressCXXOfBaseClass(Derived, DerivedClassDecl, BaseClassDecl,
154                                 /*NullCheckValue=*/false);
155      return RValue::get(Base);
156    }
157  }
158
159  if (Val.isAggregate()) {
160    Val = RValue::get(Val.getAggregateAddr());
161  } else {
162    // Create a temporary variable that we can bind the reference to.
163    llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()),
164                                         "reftmp");
165    if (Val.isScalar())
166      EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
167    else
168      StoreComplexToAddr(Val.getComplexVal(), Temp, false);
169    Val = RValue::get(Temp);
170  }
171
172  return Val;
173}
174
175
176/// getAccessedFieldNo - Given an encoded value and a result number, return the
177/// input field number being accessed.
178unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
179                                             const llvm::Constant *Elts) {
180  if (isa<llvm::ConstantAggregateZero>(Elts))
181    return 0;
182
183  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
184}
185
186
187//===----------------------------------------------------------------------===//
188//                         LValue Expression Emission
189//===----------------------------------------------------------------------===//
190
191RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
192  if (Ty->isVoidType()) {
193    return RValue::get(0);
194  } else if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
195    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
196    llvm::Value *U = llvm::UndefValue::get(EltTy);
197    return RValue::getComplex(std::make_pair(U, U));
198  } else if (hasAggregateLLVMType(Ty)) {
199    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
200    return RValue::getAggregate(llvm::UndefValue::get(LTy));
201  } else {
202    return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
203  }
204}
205
206RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
207                                              const char *Name) {
208  ErrorUnsupported(E, Name);
209  return GetUndefRValue(E->getType());
210}
211
212LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
213                                              const char *Name) {
214  ErrorUnsupported(E, Name);
215  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
216  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
217                          MakeQualifiers(E->getType()));
218}
219
220/// EmitLValue - Emit code to compute a designator that specifies the location
221/// of the expression.
222///
223/// This can return one of two things: a simple address or a bitfield reference.
224/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
225/// an LLVM pointer type.
226///
227/// If this returns a bitfield reference, nothing about the pointee type of the
228/// LLVM value is known: For example, it may not be a pointer to an integer.
229///
230/// If this returns a normal address, and if the lvalue's C type is fixed size,
231/// this method guarantees that the returned pointer type will point to an LLVM
232/// type of the same size of the lvalue's type.  If the lvalue has a variable
233/// length type, this is not possible.
234///
235LValue CodeGenFunction::EmitLValue(const Expr *E) {
236  switch (E->getStmtClass()) {
237  default: return EmitUnsupportedLValue(E, "l-value expression");
238
239  case Expr::BinaryOperatorClass:
240    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
241  case Expr::CallExprClass:
242  case Expr::CXXMemberCallExprClass:
243  case Expr::CXXOperatorCallExprClass:
244    return EmitCallExprLValue(cast<CallExpr>(E));
245  case Expr::VAArgExprClass:
246    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
247  case Expr::DeclRefExprClass:
248  case Expr::QualifiedDeclRefExprClass:
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::CXXConditionDeclExprClass:
262    return EmitCXXConditionDeclLValue(cast<CXXConditionDeclExpr>(E));
263  case Expr::CXXTemporaryObjectExprClass:
264  case Expr::CXXConstructExprClass:
265    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
266  case Expr::CXXBindTemporaryExprClass:
267    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
268  case Expr::CXXExprWithTemporariesClass:
269    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
270
271  case Expr::ObjCMessageExprClass:
272    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
273  case Expr::ObjCIvarRefExprClass:
274    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
275  case Expr::ObjCPropertyRefExprClass:
276    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
277  case Expr::ObjCImplicitSetterGetterRefExprClass:
278    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
279  case Expr::ObjCSuperExprClass:
280    return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
281
282  case Expr::StmtExprClass:
283    return EmitStmtExprLValue(cast<StmtExpr>(E));
284  case Expr::UnaryOperatorClass:
285    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
286  case Expr::ArraySubscriptExprClass:
287    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
288  case Expr::ExtVectorElementExprClass:
289    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
290  case Expr::MemberExprClass:
291    return EmitMemberExpr(cast<MemberExpr>(E));
292  case Expr::CompoundLiteralExprClass:
293    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
294  case Expr::ConditionalOperatorClass:
295    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
296  case Expr::ChooseExprClass:
297    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
298  case Expr::ImplicitCastExprClass:
299  case Expr::CStyleCastExprClass:
300  case Expr::CXXFunctionalCastExprClass:
301  case Expr::CXXStaticCastExprClass:
302  case Expr::CXXDynamicCastExprClass:
303  case Expr::CXXReinterpretCastExprClass:
304  case Expr::CXXConstCastExprClass:
305    return EmitCastLValue(cast<CastExpr>(E));
306  case Expr::CXXZeroInitValueExprClass:
307    return EmitNullInitializationLValue(cast<CXXZeroInitValueExpr>(E));
308  }
309}
310
311llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
312                                               QualType Ty) {
313  llvm::Value *V = Builder.CreateLoad(Addr, Volatile, "tmp");
314
315  // Bool can have different representation in memory than in registers.
316  if (Ty->isBooleanType())
317    if (V->getType() != llvm::Type::getInt1Ty(VMContext))
318      V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
319
320  return V;
321}
322
323void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
324                                        bool Volatile, QualType Ty) {
325
326  if (Ty->isBooleanType()) {
327    // Bool can have different representation in memory than in registers.
328    const llvm::Type *SrcTy = Value->getType();
329    const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
330    if (DstPtr->getElementType() != SrcTy) {
331      const llvm::Type *MemTy =
332        llvm::PointerType::get(SrcTy, DstPtr->getAddressSpace());
333      Addr = Builder.CreateBitCast(Addr, MemTy, "storetmp");
334    }
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    llvm::Value *read_weak = CGM.getObjCRuntime().EmitObjCWeakRead(*this,
347                                                                   AddrWeakObj);
348    return RValue::get(read_weak);
349  }
350
351  if (LV.isSimple()) {
352    llvm::Value *Ptr = LV.getAddress();
353    const llvm::Type *EltTy =
354      cast<llvm::PointerType>(Ptr->getType())->getElementType();
355
356    // Simple scalar l-value.
357    if (EltTy->isSingleValueType())
358      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
359                                          ExprType));
360
361    assert(ExprType->isFunctionType() && "Unknown scalar value");
362    return RValue::get(Ptr);
363  }
364
365  if (LV.isVectorElt()) {
366    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
367                                          LV.isVolatileQualified(), "tmp");
368    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
369                                                    "vecext"));
370  }
371
372  // If this is a reference to a subset of the elements of a vector, either
373  // shuffle the input or extract/insert them as appropriate.
374  if (LV.isExtVectorElt())
375    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
376
377  if (LV.isBitfield())
378    return EmitLoadOfBitfieldLValue(LV, ExprType);
379
380  if (LV.isPropertyRef())
381    return EmitLoadOfPropertyRefLValue(LV, ExprType);
382
383  assert(LV.isKVCRef() && "Unknown LValue type!");
384  return EmitLoadOfKVCRefLValue(LV, ExprType);
385}
386
387RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
388                                                 QualType ExprType) {
389  unsigned StartBit = LV.getBitfieldStartBit();
390  unsigned BitfieldSize = LV.getBitfieldSize();
391  llvm::Value *Ptr = LV.getBitfieldAddr();
392
393  const llvm::Type *EltTy =
394    cast<llvm::PointerType>(Ptr->getType())->getElementType();
395  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
396
397  // In some cases the bitfield may straddle two memory locations.  Currently we
398  // load the entire bitfield, then do the magic to sign-extend it if
399  // necessary. This results in somewhat more code than necessary for the common
400  // case (one load), since two shifts accomplish both the masking and sign
401  // extension.
402  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
403  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp");
404
405  // Shift to proper location.
406  if (StartBit)
407    Val = Builder.CreateLShr(Val, llvm::ConstantInt::get(EltTy, StartBit),
408                             "bf.lo");
409
410  // Mask off unused bits.
411  llvm::Constant *LowMask = llvm::ConstantInt::get(VMContext,
412                                llvm::APInt::getLowBitsSet(EltTySize, LowBits));
413  Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared");
414
415  // Fetch the high bits if necessary.
416  if (LowBits < BitfieldSize) {
417    unsigned HighBits = BitfieldSize - LowBits;
418    llvm::Value *HighPtr = Builder.CreateGEP(Ptr, llvm::ConstantInt::get(
419                            llvm::Type::getInt32Ty(VMContext), 1), "bf.ptr.hi");
420    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
421                                              LV.isVolatileQualified(),
422                                              "tmp");
423
424    // Mask off unused bits.
425    llvm::Constant *HighMask = llvm::ConstantInt::get(VMContext,
426                               llvm::APInt::getLowBitsSet(EltTySize, HighBits));
427    HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared");
428
429    // Shift to proper location and or in to bitfield value.
430    HighVal = Builder.CreateShl(HighVal,
431                                llvm::ConstantInt::get(EltTy, LowBits));
432    Val = Builder.CreateOr(Val, HighVal, "bf.val");
433  }
434
435  // Sign extend if necessary.
436  if (LV.isBitfieldSigned()) {
437    llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy,
438                                                    EltTySize - BitfieldSize);
439    Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits),
440                             ExtraBits, "bf.val.sext");
441  }
442
443  // The bitfield type and the normal type differ when the storage sizes differ
444  // (currently just _Bool).
445  Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp");
446
447  return RValue::get(Val);
448}
449
450RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
451                                                    QualType ExprType) {
452  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
453}
454
455RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
456                                               QualType ExprType) {
457  return EmitObjCPropertyGet(LV.getKVCRefExpr());
458}
459
460// If this is a reference to a subset of the elements of a vector, create an
461// appropriate shufflevector.
462RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
463                                                         QualType ExprType) {
464  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
465                                        LV.isVolatileQualified(), "tmp");
466
467  const llvm::Constant *Elts = LV.getExtVectorElts();
468
469  // If the result of the expression is a non-vector type, we must be extracting
470  // a single element.  Just codegen as an extractelement.
471  const VectorType *ExprVT = ExprType->getAs<VectorType>();
472  if (!ExprVT) {
473    unsigned InIdx = getAccessedFieldNo(0, Elts);
474    llvm::Value *Elt = llvm::ConstantInt::get(
475                                      llvm::Type::getInt32Ty(VMContext), InIdx);
476    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
477  }
478
479  // Always use shuffle vector to try to retain the original program structure
480  unsigned NumResultElts = ExprVT->getNumElements();
481
482  llvm::SmallVector<llvm::Constant*, 4> Mask;
483  for (unsigned i = 0; i != NumResultElts; ++i) {
484    unsigned InIdx = getAccessedFieldNo(i, Elts);
485    Mask.push_back(llvm::ConstantInt::get(
486                                     llvm::Type::getInt32Ty(VMContext), InIdx));
487  }
488
489  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
490  Vec = Builder.CreateShuffleVector(Vec,
491                                    llvm::UndefValue::get(Vec->getType()),
492                                    MaskV, "tmp");
493  return RValue::get(Vec);
494}
495
496
497
498/// EmitStoreThroughLValue - Store the specified rvalue into the specified
499/// lvalue, where both are guaranteed to the have the same type, and that type
500/// is 'Ty'.
501void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
502                                             QualType Ty) {
503  if (!Dst.isSimple()) {
504    if (Dst.isVectorElt()) {
505      // Read/modify/write the vector, inserting the new element.
506      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
507                                            Dst.isVolatileQualified(), "tmp");
508      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
509                                        Dst.getVectorIdx(), "vecins");
510      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
511      return;
512    }
513
514    // If this is an update of extended vector elements, insert them as
515    // appropriate.
516    if (Dst.isExtVectorElt())
517      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
518
519    if (Dst.isBitfield())
520      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
521
522    if (Dst.isPropertyRef())
523      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
524
525    if (Dst.isKVCRef())
526      return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
527
528    assert(0 && "Unknown LValue type");
529  }
530
531  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
532    // load of a __weak object.
533    llvm::Value *LvalueDst = Dst.getAddress();
534    llvm::Value *src = Src.getScalarVal();
535     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
536    return;
537  }
538
539  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
540    // load of a __strong object.
541    llvm::Value *LvalueDst = Dst.getAddress();
542    llvm::Value *src = Src.getScalarVal();
543    if (Dst.isObjCIvar()) {
544      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
545      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
546      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
547      llvm::Value *dst = RHS;
548      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
549      llvm::Value *LHS =
550        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
551      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
552      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
553                                              BytesBetween);
554    }
555    else if (Dst.isGlobalObjCRef())
556      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
557    else
558      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
559    return;
560  }
561
562  assert(Src.isScalar() && "Can't emit an agg store with this method");
563  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
564                    Dst.isVolatileQualified(), Ty);
565}
566
567void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
568                                                     QualType Ty,
569                                                     llvm::Value **Result) {
570  unsigned StartBit = Dst.getBitfieldStartBit();
571  unsigned BitfieldSize = Dst.getBitfieldSize();
572  llvm::Value *Ptr = Dst.getBitfieldAddr();
573
574  const llvm::Type *EltTy =
575    cast<llvm::PointerType>(Ptr->getType())->getElementType();
576  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
577
578  // Get the new value, cast to the appropriate type and masked to exactly the
579  // size of the bit-field.
580  llvm::Value *SrcVal = Src.getScalarVal();
581  llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp");
582  llvm::Constant *Mask = llvm::ConstantInt::get(VMContext,
583                           llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize));
584  NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value");
585
586  // Return the new value of the bit-field, if requested.
587  if (Result) {
588    // Cast back to the proper type for result.
589    const llvm::Type *SrcTy = SrcVal->getType();
590    llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false,
591                                                  "bf.reload.val");
592
593    // Sign extend if necessary.
594    if (Dst.isBitfieldSigned()) {
595      unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy);
596      llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy,
597                                                      SrcTySize - BitfieldSize);
598      SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits),
599                                    ExtraBits, "bf.reload.sext");
600    }
601
602    *Result = SrcTrunc;
603  }
604
605  // In some cases the bitfield may straddle two memory locations.  Emit the low
606  // part first and check to see if the high needs to be done.
607  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
608  llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(),
609                                           "bf.prev.low");
610
611  // Compute the mask for zero-ing the low part of this bitfield.
612  llvm::Constant *InvMask =
613    llvm::ConstantInt::get(VMContext,
614             ~llvm::APInt::getBitsSet(EltTySize, StartBit, StartBit + LowBits));
615
616  // Compute the new low part as
617  //   LowVal = (LowVal & InvMask) | (NewVal << StartBit),
618  // with the shift of NewVal implicitly stripping the high bits.
619  llvm::Value *NewLowVal =
620    Builder.CreateShl(NewVal, llvm::ConstantInt::get(EltTy, StartBit),
621                      "bf.value.lo");
622  LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared");
623  LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo");
624
625  // Write back.
626  Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified());
627
628  // If the low part doesn't cover the bitfield emit a high part.
629  if (LowBits < BitfieldSize) {
630    unsigned HighBits = BitfieldSize - LowBits;
631    llvm::Value *HighPtr =  Builder.CreateGEP(Ptr, llvm::ConstantInt::get(
632                            llvm::Type::getInt32Ty(VMContext), 1), "bf.ptr.hi");
633    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
634                                              Dst.isVolatileQualified(),
635                                              "bf.prev.hi");
636
637    // Compute the mask for zero-ing the high part of this bitfield.
638    llvm::Constant *InvMask =
639      llvm::ConstantInt::get(VMContext, ~llvm::APInt::getLowBitsSet(EltTySize,
640                               HighBits));
641
642    // Compute the new high part as
643    //   HighVal = (HighVal & InvMask) | (NewVal lshr LowBits),
644    // where the high bits of NewVal have already been cleared and the
645    // shift stripping the low bits.
646    llvm::Value *NewHighVal =
647      Builder.CreateLShr(NewVal, llvm::ConstantInt::get(EltTy, LowBits),
648                        "bf.value.high");
649    HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared");
650    HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi");
651
652    // Write back.
653    Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified());
654  }
655}
656
657void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
658                                                        LValue Dst,
659                                                        QualType Ty) {
660  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
661}
662
663void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
664                                                   LValue Dst,
665                                                   QualType Ty) {
666  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
667}
668
669void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
670                                                               LValue Dst,
671                                                               QualType Ty) {
672  // This access turns into a read/modify/write of the vector.  Load the input
673  // value now.
674  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
675                                        Dst.isVolatileQualified(), "tmp");
676  const llvm::Constant *Elts = Dst.getExtVectorElts();
677
678  llvm::Value *SrcVal = Src.getScalarVal();
679
680  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
681    unsigned NumSrcElts = VTy->getNumElements();
682    unsigned NumDstElts =
683       cast<llvm::VectorType>(Vec->getType())->getNumElements();
684    if (NumDstElts == NumSrcElts) {
685      // Use shuffle vector is the src and destination are the same number of
686      // elements and restore the vector mask since it is on the side it will be
687      // stored.
688      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
689      for (unsigned i = 0; i != NumSrcElts; ++i) {
690        unsigned InIdx = getAccessedFieldNo(i, Elts);
691        Mask[InIdx] = llvm::ConstantInt::get(
692                                          llvm::Type::getInt32Ty(VMContext), i);
693      }
694
695      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
696      Vec = Builder.CreateShuffleVector(SrcVal,
697                                        llvm::UndefValue::get(Vec->getType()),
698                                        MaskV, "tmp");
699    } else if (NumDstElts > NumSrcElts) {
700      // Extended the source vector to the same length and then shuffle it
701      // into the destination.
702      // FIXME: since we're shuffling with undef, can we just use the indices
703      //        into that?  This could be simpler.
704      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
705      unsigned i;
706      for (i = 0; i != NumSrcElts; ++i)
707        ExtMask.push_back(llvm::ConstantInt::get(
708                                         llvm::Type::getInt32Ty(VMContext), i));
709      for (; i != NumDstElts; ++i)
710        ExtMask.push_back(llvm::UndefValue::get(
711                                            llvm::Type::getInt32Ty(VMContext)));
712      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
713                                                        ExtMask.size());
714      llvm::Value *ExtSrcVal =
715        Builder.CreateShuffleVector(SrcVal,
716                                    llvm::UndefValue::get(SrcVal->getType()),
717                                    ExtMaskV, "tmp");
718      // build identity
719      llvm::SmallVector<llvm::Constant*, 4> Mask;
720      for (unsigned i = 0; i != NumDstElts; ++i) {
721        Mask.push_back(llvm::ConstantInt::get(
722                                        llvm::Type::getInt32Ty(VMContext), i));
723      }
724      // modify when what gets shuffled in
725      for (unsigned i = 0; i != NumSrcElts; ++i) {
726        unsigned Idx = getAccessedFieldNo(i, Elts);
727        Mask[Idx] = llvm::ConstantInt::get(
728                               llvm::Type::getInt32Ty(VMContext), i+NumDstElts);
729      }
730      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
731      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
732    } else {
733      // We should never shorten the vector
734      assert(0 && "unexpected shorten vector length");
735    }
736  } else {
737    // If the Src is a scalar (not a vector) it must be updating one element.
738    unsigned InIdx = getAccessedFieldNo(0, Elts);
739    llvm::Value *Elt = llvm::ConstantInt::get(
740                                      llvm::Type::getInt32Ty(VMContext), InIdx);
741    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
742  }
743
744  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
745}
746
747// setObjCGCLValueClass - sets class of he lvalue for the purpose of
748// generating write-barries API. It is currently a global, ivar,
749// or neither.
750static
751void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E, LValue &LV) {
752  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
753    return;
754
755  if (isa<ObjCIvarRefExpr>(E)) {
756    LV.SetObjCIvar(LV, true);
757    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
758    LV.setBaseIvarExp(Exp->getBase());
759    LV.SetObjCArray(LV, E->getType()->isArrayType());
760    return;
761  }
762  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
763    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
764      if ((VD->isBlockVarDecl() && !VD->hasLocalStorage()) ||
765          VD->isFileVarDecl())
766        LV.SetGlobalObjCRef(LV, true);
767    }
768    LV.SetObjCArray(LV, E->getType()->isArrayType());
769  }
770  else if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E))
771    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
772  else if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
773    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
774    if (LV.isObjCIvar()) {
775      // If cast is to a structure pointer, follow gcc's behavior and make it
776      // a non-ivar write-barrier.
777      QualType ExpTy = E->getType();
778      if (ExpTy->isPointerType())
779        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
780      if (ExpTy->isRecordType())
781        LV.SetObjCIvar(LV, false);
782    }
783  }
784  else if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E))
785    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
786  else if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E))
787    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
788  else if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
789    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
790    if (LV.isObjCIvar() && !LV.isObjCArray())
791      // Using array syntax to assigning to what an ivar points to is not
792      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
793      LV.SetObjCIvar(LV, false);
794    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
795      // Using array syntax to assigning to what global points to is not
796      // same as assigning to the global itself. {id *G;} G[i] = 0;
797      LV.SetGlobalObjCRef(LV, false);
798  }
799  else if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
800    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
801    // We don't know if member is an 'ivar', but this flag is looked at
802    // only in the context of LV.isObjCIvar().
803    LV.SetObjCArray(LV, E->getType()->isArrayType());
804  }
805}
806
807LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
808  const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
809
810  if (VD && (VD->isBlockVarDecl() || isa<ParmVarDecl>(VD) ||
811        isa<ImplicitParamDecl>(VD))) {
812    LValue LV;
813    bool NonGCable = VD->hasLocalStorage() &&
814      !VD->hasAttr<BlocksAttr>();
815    if (VD->hasExternalStorage()) {
816      llvm::Value *V = CGM.GetAddrOfGlobalVar(VD);
817      if (VD->getType()->isReferenceType())
818        V = Builder.CreateLoad(V, "tmp");
819      LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
820    } else {
821      llvm::Value *V = LocalDeclMap[VD];
822      assert(V && "DeclRefExpr not entered in LocalDeclMap?");
823
824      Qualifiers Quals = MakeQualifiers(E->getType());
825      // local variables do not get their gc attribute set.
826      // local static?
827      if (NonGCable) Quals.removeObjCGCAttr();
828
829      if (VD->hasAttr<BlocksAttr>()) {
830        V = Builder.CreateStructGEP(V, 1, "forwarding");
831        V = Builder.CreateLoad(V, false);
832        V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
833                                    VD->getNameAsString());
834      }
835      if (VD->getType()->isReferenceType())
836        V = Builder.CreateLoad(V, "tmp");
837      LV = LValue::MakeAddr(V, Quals);
838    }
839    LValue::SetObjCNonGC(LV, NonGCable);
840    setObjCGCLValueClass(getContext(), E, LV);
841    return LV;
842  } else if (VD && VD->isFileVarDecl()) {
843    llvm::Value *V = CGM.GetAddrOfGlobalVar(VD);
844    if (VD->getType()->isReferenceType())
845      V = Builder.CreateLoad(V, "tmp");
846    LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
847    setObjCGCLValueClass(getContext(), E, LV);
848    return LV;
849  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl())) {
850    llvm::Value* V = CGM.GetAddrOfFunction(FD);
851    if (!FD->hasPrototype()) {
852      if (const FunctionProtoType *Proto =
853              FD->getType()->getAs<FunctionProtoType>()) {
854        // Ugly case: for a K&R-style definition, the type of the definition
855        // isn't the same as the type of a use.  Correct for this with a
856        // bitcast.
857        QualType NoProtoType =
858            getContext().getFunctionNoProtoType(Proto->getResultType());
859        NoProtoType = getContext().getPointerType(NoProtoType);
860        V = Builder.CreateBitCast(V, ConvertType(NoProtoType), "tmp");
861      }
862    }
863    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
864  } else if (const ImplicitParamDecl *IPD =
865      dyn_cast<ImplicitParamDecl>(E->getDecl())) {
866    llvm::Value *V = LocalDeclMap[IPD];
867    assert(V && "BlockVarDecl not entered in LocalDeclMap?");
868    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
869  } else if (const QualifiedDeclRefExpr *QDRExpr =
870             dyn_cast<QualifiedDeclRefExpr>(E)) {
871    return EmitPointerToDataMemberLValue(QDRExpr);
872  }
873  assert(0 && "Unimp declref");
874  //an invalid LValue, but the assert will
875  //ensure that this point is never reached.
876  return LValue();
877}
878
879LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
880  return LValue::MakeAddr(GetAddrOfBlockDecl(E), MakeQualifiers(E->getType()));
881}
882
883LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
884  // __extension__ doesn't affect lvalue-ness.
885  if (E->getOpcode() == UnaryOperator::Extension)
886    return EmitLValue(E->getSubExpr());
887
888  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
889  switch (E->getOpcode()) {
890  default: assert(0 && "Unknown unary operator lvalue!");
891  case UnaryOperator::Deref:
892    {
893      QualType T = E->getSubExpr()->getType()->getPointeeType();
894      assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
895
896      Qualifiers Quals = MakeQualifiers(T);
897      Quals.setAddressSpace(ExprTy.getAddressSpace());
898
899      LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), Quals);
900     // We should not generate __weak write barrier on indirect reference
901     // of a pointer to object; as in void foo (__weak id *param); *param = 0;
902     // But, we continue to generate __strong write barrier on indirect write
903     // into a pointer to object.
904     if (getContext().getLangOptions().ObjC1 &&
905         getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
906         LV.isObjCWeak())
907       LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
908     return LV;
909    }
910  case UnaryOperator::Real:
911  case UnaryOperator::Imag:
912    LValue LV = EmitLValue(E->getSubExpr());
913    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
914    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
915                                                    Idx, "idx"),
916                            MakeQualifiers(ExprTy));
917  }
918}
919
920LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
921  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E),
922                          Qualifiers());
923}
924
925LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
926  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E),
927                          Qualifiers());
928}
929
930
931LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
932  std::string GlobalVarName;
933
934  switch (Type) {
935  default:
936    assert(0 && "Invalid type");
937  case PredefinedExpr::Func:
938    GlobalVarName = "__func__.";
939    break;
940  case PredefinedExpr::Function:
941    GlobalVarName = "__FUNCTION__.";
942    break;
943  case PredefinedExpr::PrettyFunction:
944    GlobalVarName = "__PRETTY_FUNCTION__.";
945    break;
946  }
947
948  llvm::StringRef FnName = CurFn->getName();
949  if (FnName.startswith("\01"))
950    FnName = FnName.substr(1);
951  GlobalVarName += FnName;
952
953  std::string FunctionName =
954    PredefinedExpr::ComputeName(getContext(), (PredefinedExpr::IdentType)Type,
955                                CurCodeDecl);
956
957  llvm::Constant *C =
958    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
959  return LValue::MakeAddr(C, Qualifiers());
960}
961
962LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
963  switch (E->getIdentType()) {
964  default:
965    return EmitUnsupportedLValue(E, "predefined expression");
966  case PredefinedExpr::Func:
967  case PredefinedExpr::Function:
968  case PredefinedExpr::PrettyFunction:
969    return EmitPredefinedFunctionName(E->getIdentType());
970  }
971}
972
973LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
974  // The index must always be an integer, which is not an aggregate.  Emit it.
975  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
976  QualType IdxTy  = E->getIdx()->getType();
977  bool IdxSigned = IdxTy->isSignedIntegerType();
978
979  // If the base is a vector type, then we are forming a vector element lvalue
980  // with this subscript.
981  if (E->getBase()->getType()->isVectorType()) {
982    // Emit the vector as an lvalue to get its address.
983    LValue LHS = EmitLValue(E->getBase());
984    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
985    Idx = Builder.CreateIntCast(Idx,
986                          llvm::Type::getInt32Ty(VMContext), IdxSigned, "vidx");
987    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
988                                 E->getBase()->getType().getCVRQualifiers());
989  }
990
991  // The base must be a pointer, which is not an aggregate.  Emit it.
992  llvm::Value *Base = EmitScalarExpr(E->getBase());
993
994  // Extend or truncate the index type to 32 or 64-bits.
995  unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
996  if (IdxBitwidth != LLVMPointerWidth)
997    Idx = Builder.CreateIntCast(Idx,
998                            llvm::IntegerType::get(VMContext, LLVMPointerWidth),
999                                IdxSigned, "idxprom");
1000
1001  // We know that the pointer points to a type of the correct size, unless the
1002  // size is a VLA or Objective-C interface.
1003  llvm::Value *Address = 0;
1004  if (const VariableArrayType *VAT =
1005        getContext().getAsVariableArrayType(E->getType())) {
1006    llvm::Value *VLASize = GetVLASize(VAT);
1007
1008    Idx = Builder.CreateMul(Idx, VLASize);
1009
1010    QualType BaseType = getContext().getBaseElementType(VAT);
1011
1012    uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
1013    Idx = Builder.CreateUDiv(Idx,
1014                             llvm::ConstantInt::get(Idx->getType(),
1015                                                    BaseTypeSize));
1016    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1017  } else if (const ObjCInterfaceType *OIT =
1018             dyn_cast<ObjCInterfaceType>(E->getType())) {
1019    llvm::Value *InterfaceSize =
1020      llvm::ConstantInt::get(Idx->getType(),
1021                             getContext().getTypeSize(OIT) / 8);
1022
1023    Idx = Builder.CreateMul(Idx, InterfaceSize);
1024
1025    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1026    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1027                                Idx, "arrayidx");
1028    Address = Builder.CreateBitCast(Address, Base->getType());
1029  } else {
1030    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1031  }
1032
1033  QualType T = E->getBase()->getType()->getPointeeType();
1034  assert(!T.isNull() &&
1035         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1036
1037  Qualifiers Quals = MakeQualifiers(T);
1038  Quals.setAddressSpace(E->getBase()->getType().getAddressSpace());
1039
1040  LValue LV = LValue::MakeAddr(Address, Quals);
1041  if (getContext().getLangOptions().ObjC1 &&
1042      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1043    LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1044    setObjCGCLValueClass(getContext(), E, LV);
1045  }
1046  return LV;
1047}
1048
1049static
1050llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1051                                       llvm::SmallVector<unsigned, 4> &Elts) {
1052  llvm::SmallVector<llvm::Constant *, 4> CElts;
1053
1054  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1055    CElts.push_back(llvm::ConstantInt::get(
1056                                   llvm::Type::getInt32Ty(VMContext), Elts[i]));
1057
1058  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1059}
1060
1061LValue CodeGenFunction::
1062EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1063  // Emit the base vector as an l-value.
1064  LValue Base;
1065
1066  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1067  if (!E->isArrow()) {
1068    assert(E->getBase()->getType()->isVectorType());
1069    Base = EmitLValue(E->getBase());
1070  } else {
1071    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1072    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1073    Qualifiers Quals = MakeQualifiers(PT->getPointeeType());
1074    Quals.removeObjCGCAttr();
1075    Base = LValue::MakeAddr(Ptr, Quals);
1076  }
1077
1078  // Encode the element access list into a vector of unsigned indices.
1079  llvm::SmallVector<unsigned, 4> Indices;
1080  E->getEncodedElementAccess(Indices);
1081
1082  if (Base.isSimple()) {
1083    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1084    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1085                                    Base.getVRQualifiers());
1086  }
1087  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1088
1089  llvm::Constant *BaseElts = Base.getExtVectorElts();
1090  llvm::SmallVector<llvm::Constant *, 4> CElts;
1091
1092  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1093    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1094      CElts.push_back(llvm::ConstantInt::get(
1095                                         llvm::Type::getInt32Ty(VMContext), 0));
1096    else
1097      CElts.push_back(BaseElts->getOperand(Indices[i]));
1098  }
1099  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1100  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1101                                  Base.getVRQualifiers());
1102}
1103
1104LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1105  bool isUnion = false;
1106  bool isNonGC = false;
1107  Expr *BaseExpr = E->getBase();
1108  llvm::Value *BaseValue = NULL;
1109  Qualifiers BaseQuals;
1110
1111  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1112  if (E->isArrow()) {
1113    BaseValue = EmitScalarExpr(BaseExpr);
1114    const PointerType *PTy =
1115      BaseExpr->getType()->getAs<PointerType>();
1116    if (PTy->getPointeeType()->isUnionType())
1117      isUnion = true;
1118    BaseQuals = PTy->getPointeeType().getQualifiers();
1119  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1120             isa<ObjCImplicitSetterGetterRefExpr>(
1121               BaseExpr->IgnoreParens())) {
1122    RValue RV = EmitObjCPropertyGet(BaseExpr);
1123    BaseValue = RV.getAggregateAddr();
1124    if (BaseExpr->getType()->isUnionType())
1125      isUnion = true;
1126    BaseQuals = BaseExpr->getType().getQualifiers();
1127  } else {
1128    LValue BaseLV = EmitLValue(BaseExpr);
1129    if (BaseLV.isNonGC())
1130      isNonGC = true;
1131    // FIXME: this isn't right for bitfields.
1132    BaseValue = BaseLV.getAddress();
1133    QualType BaseTy = BaseExpr->getType();
1134    if (BaseTy->isUnionType())
1135      isUnion = true;
1136    BaseQuals = BaseTy.getQualifiers();
1137  }
1138
1139  FieldDecl *Field = dyn_cast<FieldDecl>(E->getMemberDecl());
1140  // FIXME: Handle non-field member expressions
1141  assert(Field && "No code generation for non-field member references");
1142  LValue MemExpLV = EmitLValueForField(BaseValue, Field, isUnion,
1143                                       BaseQuals.getCVRQualifiers());
1144  LValue::SetObjCNonGC(MemExpLV, isNonGC);
1145  setObjCGCLValueClass(getContext(), E, MemExpLV);
1146  return MemExpLV;
1147}
1148
1149LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
1150                                              FieldDecl* Field,
1151                                              unsigned CVRQualifiers) {
1152  CodeGenTypes::BitFieldInfo Info = CGM.getTypes().getBitFieldInfo(Field);
1153
1154  // FIXME: CodeGenTypes should expose a method to get the appropriate type for
1155  // FieldTy (the appropriate type is ABI-dependent).
1156  const llvm::Type *FieldTy =
1157    CGM.getTypes().ConvertTypeForMem(Field->getType());
1158  const llvm::PointerType *BaseTy =
1159  cast<llvm::PointerType>(BaseValue->getType());
1160  unsigned AS = BaseTy->getAddressSpace();
1161  BaseValue = Builder.CreateBitCast(BaseValue,
1162                                    llvm::PointerType::get(FieldTy, AS),
1163                                    "tmp");
1164
1165  llvm::Value *Idx =
1166    llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Info.FieldNo);
1167  llvm::Value *V = Builder.CreateGEP(BaseValue, Idx, "tmp");
1168
1169  return LValue::MakeBitfield(V, Info.Start, Info.Size,
1170                              Field->getType()->isSignedIntegerType(),
1171                            Field->getType().getCVRQualifiers()|CVRQualifiers);
1172}
1173
1174LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
1175                                           FieldDecl* Field,
1176                                           bool isUnion,
1177                                           unsigned CVRQualifiers) {
1178  if (Field->isBitField())
1179    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1180
1181  unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
1182  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1183
1184  // Match union field type.
1185  if (isUnion) {
1186    const llvm::Type *FieldTy =
1187      CGM.getTypes().ConvertTypeForMem(Field->getType());
1188    const llvm::PointerType * BaseTy =
1189      cast<llvm::PointerType>(BaseValue->getType());
1190    unsigned AS = BaseTy->getAddressSpace();
1191    V = Builder.CreateBitCast(V,
1192                              llvm::PointerType::get(FieldTy, AS),
1193                              "tmp");
1194  }
1195  if (Field->getType()->isReferenceType())
1196    V = Builder.CreateLoad(V, "tmp");
1197
1198  Qualifiers Quals = MakeQualifiers(Field->getType());
1199  Quals.addCVRQualifiers(CVRQualifiers);
1200  // __weak attribute on a field is ignored.
1201  if (Quals.getObjCGCAttr() == Qualifiers::Weak)
1202    Quals.removeObjCGCAttr();
1203
1204  return LValue::MakeAddr(V, Quals);
1205}
1206
1207LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
1208  const llvm::Type *LTy = ConvertType(E->getType());
1209  llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral");
1210
1211  const Expr* InitExpr = E->getInitializer();
1212  LValue Result = LValue::MakeAddr(DeclPtr, MakeQualifiers(E->getType()));
1213
1214  if (E->getType()->isComplexType()) {
1215    EmitComplexExprIntoAddr(InitExpr, DeclPtr, false);
1216  } else if (hasAggregateLLVMType(E->getType())) {
1217    EmitAnyExpr(InitExpr, DeclPtr, false);
1218  } else {
1219    EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType());
1220  }
1221
1222  return Result;
1223}
1224
1225LValue
1226CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
1227  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1228    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1229    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1230    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1231
1232    llvm::Value *Cond = EvaluateExprAsBool(E->getCond());
1233    Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
1234
1235    EmitBlock(LHSBlock);
1236
1237    LValue LHS = EmitLValue(E->getLHS());
1238    if (!LHS.isSimple())
1239      return EmitUnsupportedLValue(E, "conditional operator");
1240
1241    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),
1242                                         "condtmp");
1243
1244    Builder.CreateStore(LHS.getAddress(), Temp);
1245    EmitBranch(ContBlock);
1246
1247    EmitBlock(RHSBlock);
1248    LValue RHS = EmitLValue(E->getRHS());
1249    if (!RHS.isSimple())
1250      return EmitUnsupportedLValue(E, "conditional operator");
1251
1252    Builder.CreateStore(RHS.getAddress(), Temp);
1253    EmitBranch(ContBlock);
1254
1255    EmitBlock(ContBlock);
1256
1257    Temp = Builder.CreateLoad(Temp, "lv");
1258    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1259  }
1260
1261  // ?: here should be an aggregate.
1262  assert((hasAggregateLLVMType(E->getType()) &&
1263          !E->getType()->isAnyComplexType()) &&
1264         "Unexpected conditional operator!");
1265
1266  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1267  EmitAggExpr(E, Temp, false);
1268
1269  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1270}
1271
1272/// EmitCastLValue - Casts are never lvalues.  If a cast is needed by the code
1273/// generator in an lvalue context, then it must mean that we need the address
1274/// of an aggregate in order to access one of its fields.  This can happen for
1275/// all the reasons that casts are permitted with aggregate result, including
1276/// noop aggregate casts, and cast from scalar to union.
1277LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1278  switch (E->getCastKind()) {
1279  default:
1280    // If this is an lvalue cast, treat it as a no-op.
1281    // FIXME: We shouldn't need to check for this explicitly!
1282    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
1283      if (ICE->isLvalueCast())
1284        return EmitLValue(E->getSubExpr());
1285
1286    assert(0 && "Unhandled cast!");
1287
1288  case CastExpr::CK_NoOp:
1289  case CastExpr::CK_ConstructorConversion:
1290  case CastExpr::CK_UserDefinedConversion:
1291    return EmitLValue(E->getSubExpr());
1292
1293  case CastExpr::CK_DerivedToBase: {
1294    const RecordType *DerivedClassTy =
1295      E->getSubExpr()->getType()->getAs<RecordType>();
1296    CXXRecordDecl *DerivedClassDecl =
1297      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1298
1299    const RecordType *BaseClassTy = E->getType()->getAs<RecordType>();
1300    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl());
1301
1302    LValue LV = EmitLValue(E->getSubExpr());
1303
1304    // Perform the derived-to-base conversion
1305    llvm::Value *Base =
1306      GetAddressCXXOfBaseClass(LV.getAddress(), DerivedClassDecl,
1307                               BaseClassDecl, /*NullCheckValue=*/false);
1308
1309    return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
1310  }
1311
1312  case CastExpr::CK_ToUnion: {
1313    llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1314    EmitAnyExpr(E->getSubExpr(), Temp, false);
1315
1316    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1317    }
1318  }
1319}
1320
1321LValue CodeGenFunction::EmitNullInitializationLValue(
1322                                              const CXXZeroInitValueExpr *E) {
1323  QualType Ty = E->getType();
1324  const llvm::Type *LTy = ConvertTypeForMem(Ty);
1325  llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
1326  unsigned Align = getContext().getTypeAlign(Ty)/8;
1327  Alloc->setAlignment(Align);
1328  LValue lvalue = LValue::MakeAddr(Alloc, Qualifiers());
1329  EmitMemSetToZero(lvalue.getAddress(), Ty);
1330  return lvalue;
1331}
1332
1333//===--------------------------------------------------------------------===//
1334//                             Expression Emission
1335//===--------------------------------------------------------------------===//
1336
1337
1338RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
1339  // Builtins never have block type.
1340  if (E->getCallee()->getType()->isBlockPointerType())
1341    return EmitBlockCallExpr(E);
1342
1343  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1344    return EmitCXXMemberCallExpr(CE);
1345
1346  const Decl *TargetDecl = 0;
1347  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1348    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1349      TargetDecl = DRE->getDecl();
1350      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1351        if (unsigned builtinID = FD->getBuiltinID())
1352          return EmitBuiltinExpr(FD, builtinID, E);
1353    }
1354  }
1355
1356  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1357    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1358      return EmitCXXOperatorMemberCallExpr(CE, MD);
1359
1360  if (isa<CXXPseudoDestructorExpr>(E->getCallee())) {
1361    // C++ [expr.pseudo]p1:
1362    //   The result shall only be used as the operand for the function call
1363    //   operator (), and the result of such a call has type void. The only
1364    //   effect is the evaluation of the postfix-expression before the dot or
1365    //   arrow.
1366    EmitScalarExpr(E->getCallee());
1367    return RValue::get(0);
1368  }
1369
1370  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1371  return EmitCall(Callee, E->getCallee()->getType(),
1372                  E->arg_begin(), E->arg_end(), TargetDecl);
1373}
1374
1375LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1376  // Comma expressions just emit their LHS then their RHS as an l-value.
1377  if (E->getOpcode() == BinaryOperator::Comma) {
1378    EmitAnyExpr(E->getLHS());
1379    return EmitLValue(E->getRHS());
1380  }
1381
1382  if (E->getOpcode() == BinaryOperator::PtrMemD)
1383    return EmitPointerToDataMemberBinaryExpr(E);
1384
1385  // Can only get l-value for binary operator expressions which are a
1386  // simple assignment of aggregate type.
1387  if (E->getOpcode() != BinaryOperator::Assign)
1388    return EmitUnsupportedLValue(E, "binary l-value expression");
1389
1390  if (!hasAggregateLLVMType(E->getType())) {
1391    // Emit the LHS as an l-value.
1392    LValue LV = EmitLValue(E->getLHS());
1393
1394    llvm::Value *RHS = EmitScalarExpr(E->getRHS());
1395    EmitStoreOfScalar(RHS, LV.getAddress(), LV.isVolatileQualified(),
1396                      E->getType());
1397    return LV;
1398  }
1399
1400  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1401  EmitAggExpr(E, Temp, false);
1402  // FIXME: Are these qualifiers correct?
1403  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1404}
1405
1406LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
1407  RValue RV = EmitCallExpr(E);
1408
1409  if (RV.isScalar()) {
1410    assert(E->getCallReturnType()->isReferenceType() &&
1411           "Can't have a scalar return unless the return type is a "
1412           "reference type!");
1413
1414    return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
1415  }
1416
1417  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1418}
1419
1420LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
1421  // FIXME: This shouldn't require another copy.
1422  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1423  EmitAggExpr(E, Temp, false);
1424  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1425}
1426
1427LValue
1428CodeGenFunction::EmitCXXConditionDeclLValue(const CXXConditionDeclExpr *E) {
1429  EmitLocalBlockVarDecl(*E->getVarDecl());
1430  return EmitDeclRefLValue(E);
1431}
1432
1433LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
1434  llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), "tmp");
1435  EmitCXXConstructExpr(Temp, E);
1436  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1437}
1438
1439LValue
1440CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
1441  LValue LV = EmitLValue(E->getSubExpr());
1442
1443  PushCXXTemporary(E->getTemporary(), LV.getAddress());
1444
1445  return LV;
1446}
1447
1448LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
1449  // Can only get l-value for message expression returning aggregate type
1450  RValue RV = EmitObjCMessageExpr(E);
1451  // FIXME: can this be volatile?
1452  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1453}
1454
1455llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
1456                                             const ObjCIvarDecl *Ivar) {
1457  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
1458}
1459
1460LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
1461                                          llvm::Value *BaseValue,
1462                                          const ObjCIvarDecl *Ivar,
1463                                          unsigned CVRQualifiers) {
1464  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
1465                                                   Ivar, CVRQualifiers);
1466}
1467
1468LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
1469  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
1470  llvm::Value *BaseValue = 0;
1471  const Expr *BaseExpr = E->getBase();
1472  Qualifiers BaseQuals;
1473  QualType ObjectTy;
1474  if (E->isArrow()) {
1475    BaseValue = EmitScalarExpr(BaseExpr);
1476    ObjectTy = BaseExpr->getType()->getPointeeType();
1477    BaseQuals = ObjectTy.getQualifiers();
1478  } else {
1479    LValue BaseLV = EmitLValue(BaseExpr);
1480    // FIXME: this isn't right for bitfields.
1481    BaseValue = BaseLV.getAddress();
1482    ObjectTy = BaseExpr->getType();
1483    BaseQuals = ObjectTy.getQualifiers();
1484  }
1485
1486  LValue LV =
1487    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
1488                      BaseQuals.getCVRQualifiers());
1489  setObjCGCLValueClass(getContext(), E, LV);
1490  return LV;
1491}
1492
1493LValue
1494CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
1495  // This is a special l-value that just issues sends when we load or store
1496  // through it.
1497  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
1498}
1499
1500LValue
1501CodeGenFunction::EmitObjCKVCRefLValue(
1502                                const ObjCImplicitSetterGetterRefExpr *E) {
1503  // This is a special l-value that just issues sends when we load or store
1504  // through it.
1505  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
1506}
1507
1508LValue
1509CodeGenFunction::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
1510  return EmitUnsupportedLValue(E, "use of super");
1511}
1512
1513LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
1514
1515  // Can only get l-value for message expression returning aggregate type
1516  RValue RV = EmitAnyExprToTemp(E);
1517  // FIXME: can this be volatile?
1518  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1519}
1520
1521
1522LValue CodeGenFunction::EmitPointerToDataMemberLValue(
1523                                              const QualifiedDeclRefExpr *E) {
1524  const FieldDecl *Field = cast<FieldDecl>(E->getDecl());
1525  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Field->getDeclContext());
1526  QualType NNSpecTy =
1527    getContext().getCanonicalType(
1528      getContext().getTypeDeclType(const_cast<CXXRecordDecl*>(ClassDecl)));
1529  NNSpecTy = getContext().getPointerType(NNSpecTy);
1530  llvm::Value *V = llvm::Constant::getNullValue(ConvertType(NNSpecTy));
1531  LValue MemExpLV = EmitLValueForField(V, const_cast<FieldDecl*>(Field),
1532                                       /*isUnion*/false, /*Qualifiers*/0);
1533  const llvm::Type* ResultType = ConvertType(
1534                                             getContext().getPointerDiffType());
1535  V = Builder.CreatePtrToInt(MemExpLV.getAddress(), ResultType,
1536                             "datamember");
1537  LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1538  return LV;
1539}
1540
1541RValue CodeGenFunction::EmitCall(llvm::Value *Callee, QualType CalleeType,
1542                                 CallExpr::const_arg_iterator ArgBeg,
1543                                 CallExpr::const_arg_iterator ArgEnd,
1544                                 const Decl *TargetDecl) {
1545  // Get the actual function type. The callee type will always be a pointer to
1546  // function type or a block pointer type.
1547  assert(CalleeType->isFunctionPointerType() &&
1548         "Call must have function pointer type!");
1549
1550  CalleeType = getContext().getCanonicalType(CalleeType);
1551
1552  QualType FnType = cast<PointerType>(CalleeType)->getPointeeType();
1553  QualType ResultType = cast<FunctionType>(FnType)->getResultType();
1554
1555  CallArgList Args;
1556  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
1557
1558  // FIXME: We should not need to do this, it should be part of the function
1559  // type.
1560  unsigned CallingConvention = 0;
1561  if (const llvm::Function *F =
1562      dyn_cast<llvm::Function>(Callee->stripPointerCasts()))
1563    CallingConvention = F->getCallingConv();
1564  return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args,
1565                                                 CallingConvention),
1566                  Callee, Args, TargetDecl);
1567}
1568
1569LValue CodeGenFunction::EmitPointerToDataMemberBinaryExpr(
1570                                                    const BinaryOperator *E) {
1571  llvm::Value *BaseV = EmitLValue(E->getLHS()).getAddress();
1572  const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
1573  BaseV = Builder.CreateBitCast(BaseV, i8Ty);
1574  LValue RHSLV = EmitLValue(E->getRHS());
1575  llvm::Value *OffsetV =
1576    EmitLoadOfLValue(RHSLV, E->getRHS()->getType()).getScalarVal();
1577  const llvm::Type* ResultType = ConvertType(getContext().getPointerDiffType());
1578  OffsetV = Builder.CreateBitCast(OffsetV, ResultType);
1579  llvm::Value *AddV = Builder.CreateInBoundsGEP(BaseV, OffsetV, "add.ptr");
1580  QualType Ty = E->getRHS()->getType();
1581  const MemberPointerType *MemPtrType = Ty->getAs<MemberPointerType>();
1582  Ty = MemPtrType->getPointeeType();
1583  const llvm::Type* PType =
1584  ConvertType(getContext().getPointerType(Ty));
1585  AddV = Builder.CreateBitCast(AddV, PType);
1586  LValue LV = LValue::MakeAddr(AddV, MakeQualifiers(Ty));
1587  return LV;
1588}
1589
1590