CGExpr.cpp revision 7f215c12af4c3e7f81b24102a676aabfdb4e1566 
1//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CodeGenModule.h"
16#include "CGCall.h"
17#include "CGRecordLayout.h"
18#include "CGObjCRuntime.h"
19#include "clang/AST/ASTContext.h"
20#include "clang/AST/DeclObjC.h"
21#include "llvm/Intrinsics.h"
22#include "clang/Frontend/CodeGenOptions.h"
23#include "llvm/Target/TargetData.h"
24using namespace clang;
25using namespace CodeGen;
26
27//===--------------------------------------------------------------------===//
28//                        Miscellaneous Helper Methods
29//===--------------------------------------------------------------------===//
30
31/// CreateTempAlloca - This creates a alloca and inserts it into the entry
32/// block.
33llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
34                                                    const llvm::Twine &Name) {
35  if (!Builder.isNamePreserving())
36    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
37  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
38}
39
40void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
41                                     llvm::Value *Init) {
42  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
43  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
44  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
45}
46
47llvm::Value *CodeGenFunction::CreateIRTemp(QualType Ty,
48                                           const llvm::Twine &Name) {
49  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
50  // FIXME: Should we prefer the preferred type alignment here?
51  CharUnits Align = getContext().getTypeAlignInChars(Ty);
52  Alloc->setAlignment(Align.getQuantity());
53  return Alloc;
54}
55
56llvm::Value *CodeGenFunction::CreateMemTemp(QualType Ty,
57                                            const llvm::Twine &Name) {
58  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
59  // FIXME: Should we prefer the preferred type alignment here?
60  CharUnits Align = getContext().getTypeAlignInChars(Ty);
61  Alloc->setAlignment(Align.getQuantity());
62  return Alloc;
63}
64
65/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
66/// expression and compare the result against zero, returning an Int1Ty value.
67llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
68  QualType BoolTy = getContext().BoolTy;
69  if (E->getType()->isMemberFunctionPointerType()) {
70    LValue LV = EmitAggExprToLValue(E);
71
72    // Get the pointer.
73    llvm::Value *FuncPtr = Builder.CreateStructGEP(LV.getAddress(), 0,
74                                                   "src.ptr");
75    FuncPtr = Builder.CreateLoad(FuncPtr);
76
77    llvm::Value *IsNotNull =
78      Builder.CreateICmpNE(FuncPtr,
79                            llvm::Constant::getNullValue(FuncPtr->getType()),
80                            "tobool");
81
82    return IsNotNull;
83  }
84  if (!E->getType()->isAnyComplexType())
85    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
86
87  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
88}
89
90/// EmitAnyExpr - Emit code to compute the specified expression which can have
91/// any type.  The result is returned as an RValue struct.  If this is an
92/// aggregate expression, the aggloc/agglocvolatile arguments indicate where the
93/// result should be returned.
94RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc,
95                                    bool IsAggLocVolatile, bool IgnoreResult,
96                                    bool IsInitializer) {
97  if (!hasAggregateLLVMType(E->getType()))
98    return RValue::get(EmitScalarExpr(E, IgnoreResult));
99  else if (E->getType()->isAnyComplexType())
100    return RValue::getComplex(EmitComplexExpr(E, false, false,
101                                              IgnoreResult, IgnoreResult));
102
103  EmitAggExpr(E, AggLoc, IsAggLocVolatile, IgnoreResult, IsInitializer);
104  return RValue::getAggregate(AggLoc, IsAggLocVolatile);
105}
106
107/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
108/// always be accessible even if no aggregate location is provided.
109RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E,
110                                          bool IsAggLocVolatile,
111                                          bool IsInitializer) {
112  llvm::Value *AggLoc = 0;
113
114  if (hasAggregateLLVMType(E->getType()) &&
115      !E->getType()->isAnyComplexType())
116    AggLoc = CreateMemTemp(E->getType(), "agg.tmp");
117  return EmitAnyExpr(E, AggLoc, IsAggLocVolatile, /*IgnoreResult=*/false,
118                     IsInitializer);
119}
120
121/// EmitAnyExprToMem - Evaluate an expression into a given memory
122/// location.
123void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
124                                       llvm::Value *Location,
125                                       bool IsLocationVolatile,
126                                       bool IsInit) {
127  if (E->getType()->isComplexType())
128    EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
129  else if (hasAggregateLLVMType(E->getType()))
130    EmitAggExpr(E, Location, IsLocationVolatile, /*Ignore*/ false, IsInit);
131  else {
132    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
133    LValue LV = LValue::MakeAddr(Location, MakeQualifiers(E->getType()));
134    EmitStoreThroughLValue(RV, LV, E->getType());
135  }
136}
137
138/// \brief An adjustment to be made to the temporary created when emitting a
139/// reference binding, which accesses a particular subobject of that temporary.
140struct SubobjectAdjustment {
141  enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
142
143  union {
144    struct {
145      const CXXBaseSpecifierArray *BasePath;
146      const CXXRecordDecl *DerivedClass;
147    } DerivedToBase;
148
149    struct {
150      FieldDecl *Field;
151      unsigned CVRQualifiers;
152    } Field;
153  };
154
155  SubobjectAdjustment(const CXXBaseSpecifierArray *BasePath,
156                      const CXXRecordDecl *DerivedClass)
157    : Kind(DerivedToBaseAdjustment)
158  {
159    DerivedToBase.BasePath = BasePath;
160    DerivedToBase.DerivedClass = DerivedClass;
161  }
162
163  SubobjectAdjustment(FieldDecl *Field, unsigned CVRQualifiers)
164    : Kind(FieldAdjustment)
165  {
166    this->Field.Field = Field;
167    this->Field.CVRQualifiers = CVRQualifiers;
168  }
169};
170
171RValue
172CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
173                                            const NamedDecl *InitializedDecl) {
174  bool IsInitializer = InitializedDecl;
175
176  bool ShouldDestroyTemporaries = false;
177  unsigned OldNumLiveTemporaries = 0;
178
179  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
180    E = DAE->getExpr();
181
182  if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
183    ShouldDestroyTemporaries = true;
184
185    // Keep track of the current cleanup stack depth.
186    OldNumLiveTemporaries = LiveTemporaries.size();
187
188    E = TE->getSubExpr();
189  }
190
191  RValue Val;
192  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
193    // Emit the expr as an lvalue.
194    LValue LV = EmitLValue(E);
195    if (LV.isSimple()) {
196      if (ShouldDestroyTemporaries) {
197        // Pop temporaries.
198        while (LiveTemporaries.size() > OldNumLiveTemporaries)
199          PopCXXTemporary();
200      }
201
202      return RValue::get(LV.getAddress());
203    }
204
205    Val = EmitLoadOfLValue(LV, E->getType());
206
207    if (ShouldDestroyTemporaries) {
208      // Pop temporaries.
209      while (LiveTemporaries.size() > OldNumLiveTemporaries)
210        PopCXXTemporary();
211    }
212  } else {
213    QualType ResultTy = E->getType();
214
215    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
216    do {
217      if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
218        E = PE->getSubExpr();
219        continue;
220      }
221
222      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
223        if ((CE->getCastKind() == CastExpr::CK_DerivedToBase ||
224             CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) &&
225            E->getType()->isRecordType()) {
226          E = CE->getSubExpr();
227          CXXRecordDecl *Derived
228            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
229          Adjustments.push_back(SubobjectAdjustment(&CE->getBasePath(),
230                                                    Derived));
231          continue;
232        }
233
234        if (CE->getCastKind() == CastExpr::CK_NoOp) {
235          E = CE->getSubExpr();
236          continue;
237        }
238      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
239        if (ME->getBase()->isLvalue(getContext()) != Expr::LV_Valid &&
240            ME->getBase()->getType()->isRecordType()) {
241          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
242            E = ME->getBase();
243            Adjustments.push_back(SubobjectAdjustment(Field,
244                                              E->getType().getCVRQualifiers()));
245            continue;
246          }
247        }
248      }
249
250      // Nothing changed.
251      break;
252    } while (true);
253
254    Val = EmitAnyExprToTemp(E, /*IsAggLocVolatile=*/false,
255                            IsInitializer);
256
257    if (ShouldDestroyTemporaries) {
258      // Pop temporaries.
259      while (LiveTemporaries.size() > OldNumLiveTemporaries)
260        PopCXXTemporary();
261    }
262
263    if (IsInitializer) {
264      // We might have to destroy the temporary variable.
265      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
266        if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
267          if (!ClassDecl->hasTrivialDestructor()) {
268            const CXXDestructorDecl *Dtor =
269              ClassDecl->getDestructor(getContext());
270
271            {
272              DelayedCleanupBlock Scope(*this);
273              EmitCXXDestructorCall(Dtor, Dtor_Complete,
274                                    /*ForVirtualBase=*/false,
275                                    Val.getAggregateAddr());
276
277              // Make sure to jump to the exit block.
278              EmitBranch(Scope.getCleanupExitBlock());
279            }
280            if (Exceptions) {
281              EHCleanupBlock Cleanup(*this);
282              EmitCXXDestructorCall(Dtor, Dtor_Complete,
283                                    /*ForVirtualBase=*/false,
284                                    Val.getAggregateAddr());
285            }
286          }
287        }
288      }
289    }
290
291    // Check if need to perform derived-to-base casts and/or field accesses, to
292    // get from the temporary object we created (and, potentially, for which we
293    // extended the lifetime) to the subobject we're binding the reference to.
294    if (!Adjustments.empty()) {
295      llvm::Value *Object = Val.getAggregateAddr();
296      for (unsigned I = Adjustments.size(); I != 0; --I) {
297        SubobjectAdjustment &Adjustment = Adjustments[I-1];
298        switch (Adjustment.Kind) {
299        case SubobjectAdjustment::DerivedToBaseAdjustment:
300          Object = GetAddressOfBaseClass(Object,
301                                         Adjustment.DerivedToBase.DerivedClass,
302                                         *Adjustment.DerivedToBase.BasePath,
303                                         /*NullCheckValue=*/false);
304          break;
305
306        case SubobjectAdjustment::FieldAdjustment: {
307          unsigned CVR = Adjustment.Field.CVRQualifiers;
308          LValue LV = EmitLValueForField(Object, Adjustment.Field.Field, CVR);
309          if (LV.isSimple()) {
310            Object = LV.getAddress();
311            break;
312          }
313
314          // For non-simple lvalues, we actually have to create a copy of
315          // the object we're binding to.
316          QualType T = Adjustment.Field.Field->getType().getNonReferenceType()
317                                                        .getUnqualifiedType();
318          Object = CreateTempAlloca(ConvertType(T), "lv");
319          EmitStoreThroughLValue(EmitLoadOfLValue(LV, T),
320                                 LValue::MakeAddr(Object,
321                                                  Qualifiers::fromCVRMask(CVR)),
322                                 T);
323          break;
324        }
325        }
326      }
327
328      const llvm::Type *ResultPtrTy
329        = llvm::PointerType::get(ConvertType(ResultTy), 0);
330      Object = Builder.CreateBitCast(Object, ResultPtrTy, "temp");
331      return RValue::get(Object);
332    }
333  }
334
335  if (Val.isAggregate()) {
336    Val = RValue::get(Val.getAggregateAddr());
337  } else {
338    // Create a temporary variable that we can bind the reference to.
339    llvm::Value *Temp = CreateMemTemp(E->getType(), "reftmp");
340    if (Val.isScalar())
341      EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
342    else
343      StoreComplexToAddr(Val.getComplexVal(), Temp, false);
344    Val = RValue::get(Temp);
345  }
346
347  return Val;
348}
349
350
351/// getAccessedFieldNo - Given an encoded value and a result number, return the
352/// input field number being accessed.
353unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
354                                             const llvm::Constant *Elts) {
355  if (isa<llvm::ConstantAggregateZero>(Elts))
356    return 0;
357
358  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
359}
360
361void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
362  if (!CatchUndefined)
363    return;
364
365  const llvm::Type *Size_tTy
366    = llvm::IntegerType::get(VMContext, LLVMPointerWidth);
367  Address = Builder.CreateBitCast(Address, PtrToInt8Ty);
368
369  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &Size_tTy, 1);
370  const llvm::IntegerType *Int1Ty = llvm::IntegerType::get(VMContext, 1);
371
372  // In time, people may want to control this and use a 1 here.
373  llvm::Value *Arg = llvm::ConstantInt::get(Int1Ty, 0);
374  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
375  llvm::BasicBlock *Cont = createBasicBlock();
376  llvm::BasicBlock *Check = createBasicBlock();
377  llvm::Value *NegativeOne = llvm::ConstantInt::get(Size_tTy, -1ULL);
378  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
379
380  EmitBlock(Check);
381  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
382                                        llvm::ConstantInt::get(Size_tTy, Size)),
383                       Cont, getTrapBB());
384  EmitBlock(Cont);
385}
386
387
388llvm::Value *CodeGenFunction::
389EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
390                        bool isInc, bool isPre) {
391  QualType ValTy = E->getSubExpr()->getType();
392  llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy).getScalarVal();
393
394  int AmountVal = isInc ? 1 : -1;
395
396  if (ValTy->isPointerType() &&
397      ValTy->getAs<PointerType>()->isVariableArrayType()) {
398    // The amount of the addition/subtraction needs to account for the VLA size
399    ErrorUnsupported(E, "VLA pointer inc/dec");
400  }
401
402  llvm::Value *NextVal;
403  if (const llvm::PointerType *PT =
404      dyn_cast<llvm::PointerType>(InVal->getType())) {
405    llvm::Constant *Inc =
406    llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal);
407    if (!isa<llvm::FunctionType>(PT->getElementType())) {
408      QualType PTEE = ValTy->getPointeeType();
409      if (const ObjCObjectType *OIT = PTEE->getAs<ObjCObjectType>()) {
410        // Handle interface types, which are not represented with a concrete
411        // type.
412        int size = getContext().getTypeSize(OIT) / 8;
413        if (!isInc)
414          size = -size;
415        Inc = llvm::ConstantInt::get(Inc->getType(), size);
416        const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
417        InVal = Builder.CreateBitCast(InVal, i8Ty);
418        NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr");
419        llvm::Value *lhs = LV.getAddress();
420        lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty));
421        LV = LValue::MakeAddr(lhs, MakeQualifiers(ValTy));
422      } else
423        NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec");
424    } else {
425      const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
426      NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp");
427      NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec");
428      NextVal = Builder.CreateBitCast(NextVal, InVal->getType());
429    }
430  } else if (InVal->getType()->isIntegerTy(1) && isInc) {
431    // Bool++ is an interesting case, due to promotion rules, we get:
432    // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 ->
433    // Bool = ((int)Bool+1) != 0
434    // An interesting aspect of this is that increment is always true.
435    // Decrement does not have this property.
436    NextVal = llvm::ConstantInt::getTrue(VMContext);
437  } else if (isa<llvm::IntegerType>(InVal->getType())) {
438    NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal);
439
440    // Signed integer overflow is undefined behavior.
441    if (ValTy->isSignedIntegerType())
442      NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec");
443    else
444      NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec");
445  } else {
446    // Add the inc/dec to the real part.
447    if (InVal->getType()->isFloatTy())
448      NextVal =
449      llvm::ConstantFP::get(VMContext,
450                            llvm::APFloat(static_cast<float>(AmountVal)));
451    else if (InVal->getType()->isDoubleTy())
452      NextVal =
453      llvm::ConstantFP::get(VMContext,
454                            llvm::APFloat(static_cast<double>(AmountVal)));
455    else {
456      llvm::APFloat F(static_cast<float>(AmountVal));
457      bool ignored;
458      F.convert(Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero,
459                &ignored);
460      NextVal = llvm::ConstantFP::get(VMContext, F);
461    }
462    NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec");
463  }
464
465  // Store the updated result through the lvalue.
466  if (LV.isBitField())
467    EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal);
468  else
469    EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy);
470
471  // If this is a postinc, return the value read from memory, otherwise use the
472  // updated value.
473  return isPre ? NextVal : InVal;
474}
475
476
477CodeGenFunction::ComplexPairTy CodeGenFunction::
478EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
479                         bool isInc, bool isPre) {
480  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
481                                            LV.isVolatileQualified());
482
483  llvm::Value *NextVal;
484  if (isa<llvm::IntegerType>(InVal.first->getType())) {
485    uint64_t AmountVal = isInc ? 1 : -1;
486    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
487
488    // Add the inc/dec to the real part.
489    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
490  } else {
491    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
492    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
493    if (!isInc)
494      FVal.changeSign();
495    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
496
497    // Add the inc/dec to the real part.
498    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
499  }
500
501  ComplexPairTy IncVal(NextVal, InVal.second);
502
503  // Store the updated result through the lvalue.
504  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
505
506  // If this is a postinc, return the value read from memory, otherwise use the
507  // updated value.
508  return isPre ? IncVal : InVal;
509}
510
511
512//===----------------------------------------------------------------------===//
513//                         LValue Expression Emission
514//===----------------------------------------------------------------------===//
515
516RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
517  if (Ty->isVoidType())
518    return RValue::get(0);
519
520  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
521    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
522    llvm::Value *U = llvm::UndefValue::get(EltTy);
523    return RValue::getComplex(std::make_pair(U, U));
524  }
525
526  if (hasAggregateLLVMType(Ty)) {
527    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
528    return RValue::getAggregate(llvm::UndefValue::get(LTy));
529  }
530
531  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
532}
533
534RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
535                                              const char *Name) {
536  ErrorUnsupported(E, Name);
537  return GetUndefRValue(E->getType());
538}
539
540LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
541                                              const char *Name) {
542  ErrorUnsupported(E, Name);
543  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
544  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
545                          MakeQualifiers(E->getType()));
546}
547
548LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
549  LValue LV = EmitLValue(E);
550  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
551    EmitCheck(LV.getAddress(), getContext().getTypeSize(E->getType()) / 8);
552  return LV;
553}
554
555/// EmitLValue - Emit code to compute a designator that specifies the location
556/// of the expression.
557///
558/// This can return one of two things: a simple address or a bitfield reference.
559/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
560/// an LLVM pointer type.
561///
562/// If this returns a bitfield reference, nothing about the pointee type of the
563/// LLVM value is known: For example, it may not be a pointer to an integer.
564///
565/// If this returns a normal address, and if the lvalue's C type is fixed size,
566/// this method guarantees that the returned pointer type will point to an LLVM
567/// type of the same size of the lvalue's type.  If the lvalue has a variable
568/// length type, this is not possible.
569///
570LValue CodeGenFunction::EmitLValue(const Expr *E) {
571  switch (E->getStmtClass()) {
572  default: return EmitUnsupportedLValue(E, "l-value expression");
573
574  case Expr::ObjCSelectorExprClass:
575  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
576  case Expr::ObjCIsaExprClass:
577    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
578  case Expr::BinaryOperatorClass:
579    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
580  case Expr::CompoundAssignOperatorClass:
581    return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
582  case Expr::CallExprClass:
583  case Expr::CXXMemberCallExprClass:
584  case Expr::CXXOperatorCallExprClass:
585    return EmitCallExprLValue(cast<CallExpr>(E));
586  case Expr::VAArgExprClass:
587    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
588  case Expr::DeclRefExprClass:
589    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
590  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
591  case Expr::PredefinedExprClass:
592    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
593  case Expr::StringLiteralClass:
594    return EmitStringLiteralLValue(cast<StringLiteral>(E));
595  case Expr::ObjCEncodeExprClass:
596    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
597
598  case Expr::BlockDeclRefExprClass:
599    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
600
601  case Expr::CXXTemporaryObjectExprClass:
602  case Expr::CXXConstructExprClass:
603    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
604  case Expr::CXXBindTemporaryExprClass:
605    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
606  case Expr::CXXExprWithTemporariesClass:
607    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
608  case Expr::CXXZeroInitValueExprClass:
609    return EmitNullInitializationLValue(cast<CXXZeroInitValueExpr>(E));
610  case Expr::CXXDefaultArgExprClass:
611    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
612  case Expr::CXXTypeidExprClass:
613    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
614
615  case Expr::ObjCMessageExprClass:
616    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
617  case Expr::ObjCIvarRefExprClass:
618    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
619  case Expr::ObjCPropertyRefExprClass:
620    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
621  case Expr::ObjCImplicitSetterGetterRefExprClass:
622    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
623  case Expr::ObjCSuperExprClass:
624    return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
625
626  case Expr::StmtExprClass:
627    return EmitStmtExprLValue(cast<StmtExpr>(E));
628  case Expr::UnaryOperatorClass:
629    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
630  case Expr::ArraySubscriptExprClass:
631    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
632  case Expr::ExtVectorElementExprClass:
633    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
634  case Expr::MemberExprClass:
635    return EmitMemberExpr(cast<MemberExpr>(E));
636  case Expr::CompoundLiteralExprClass:
637    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
638  case Expr::ConditionalOperatorClass:
639    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
640  case Expr::ChooseExprClass:
641    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
642  case Expr::ImplicitCastExprClass:
643  case Expr::CStyleCastExprClass:
644  case Expr::CXXFunctionalCastExprClass:
645  case Expr::CXXStaticCastExprClass:
646  case Expr::CXXDynamicCastExprClass:
647  case Expr::CXXReinterpretCastExprClass:
648  case Expr::CXXConstCastExprClass:
649    return EmitCastLValue(cast<CastExpr>(E));
650  }
651}
652
653llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
654                                               QualType Ty) {
655  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
656  if (Volatile)
657    Load->setVolatile(true);
658
659  // Bool can have different representation in memory than in registers.
660  llvm::Value *V = Load;
661  if (Ty->isBooleanType())
662    if (V->getType() != llvm::Type::getInt1Ty(VMContext))
663      V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
664
665  return V;
666}
667
668void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
669                                        bool Volatile, QualType Ty) {
670
671  if (Ty->isBooleanType()) {
672    // Bool can have different representation in memory than in registers.
673    const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
674    Value = Builder.CreateIntCast(Value, DstPtr->getElementType(), false);
675  }
676  Builder.CreateStore(Value, Addr, Volatile);
677}
678
679/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
680/// method emits the address of the lvalue, then loads the result as an rvalue,
681/// returning the rvalue.
682RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
683  if (LV.isObjCWeak()) {
684    // load of a __weak object.
685    llvm::Value *AddrWeakObj = LV.getAddress();
686    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
687                                                             AddrWeakObj));
688  }
689
690  if (LV.isSimple()) {
691    llvm::Value *Ptr = LV.getAddress();
692    const llvm::Type *EltTy =
693      cast<llvm::PointerType>(Ptr->getType())->getElementType();
694
695    // Simple scalar l-value.
696    //
697    // FIXME: We shouldn't have to use isSingleValueType here.
698    if (EltTy->isSingleValueType())
699      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
700                                          ExprType));
701
702    assert(ExprType->isFunctionType() && "Unknown scalar value");
703    return RValue::get(Ptr);
704  }
705
706  if (LV.isVectorElt()) {
707    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
708                                          LV.isVolatileQualified(), "tmp");
709    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
710                                                    "vecext"));
711  }
712
713  // If this is a reference to a subset of the elements of a vector, either
714  // shuffle the input or extract/insert them as appropriate.
715  if (LV.isExtVectorElt())
716    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
717
718  if (LV.isBitField())
719    return EmitLoadOfBitfieldLValue(LV, ExprType);
720
721  if (LV.isPropertyRef())
722    return EmitLoadOfPropertyRefLValue(LV, ExprType);
723
724  assert(LV.isKVCRef() && "Unknown LValue type!");
725  return EmitLoadOfKVCRefLValue(LV, ExprType);
726}
727
728RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
729                                                 QualType ExprType) {
730  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
731
732  // Get the output type.
733  const llvm::Type *ResLTy = ConvertType(ExprType);
734  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
735
736  // Compute the result as an OR of all of the individual component accesses.
737  llvm::Value *Res = 0;
738  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
739    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
740
741    // Get the field pointer.
742    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
743
744    // Only offset by the field index if used, so that incoming values are not
745    // required to be structures.
746    if (AI.FieldIndex)
747      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
748
749    // Offset by the byte offset, if used.
750    if (AI.FieldByteOffset) {
751      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
752      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
753      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
754    }
755
756    // Cast to the access type.
757    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
758                                                    ExprType.getAddressSpace());
759    Ptr = Builder.CreateBitCast(Ptr, PTy);
760
761    // Perform the load.
762    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
763    if (AI.AccessAlignment)
764      Load->setAlignment(AI.AccessAlignment);
765
766    // Shift out unused low bits and mask out unused high bits.
767    llvm::Value *Val = Load;
768    if (AI.FieldBitStart)
769      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
770    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
771                                                            AI.TargetBitWidth),
772                            "bf.clear");
773
774    // Extend or truncate to the target size.
775    if (AI.AccessWidth < ResSizeInBits)
776      Val = Builder.CreateZExt(Val, ResLTy);
777    else if (AI.AccessWidth > ResSizeInBits)
778      Val = Builder.CreateTrunc(Val, ResLTy);
779
780    // Shift into place, and OR into the result.
781    if (AI.TargetBitOffset)
782      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
783    Res = Res ? Builder.CreateOr(Res, Val) : Val;
784  }
785
786  // If the bit-field is signed, perform the sign-extension.
787  //
788  // FIXME: This can easily be folded into the load of the high bits, which
789  // could also eliminate the mask of high bits in some situations.
790  if (Info.isSigned()) {
791    unsigned ExtraBits = ResSizeInBits - Info.getSize();
792    if (ExtraBits)
793      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
794                               ExtraBits, "bf.val.sext");
795  }
796
797  return RValue::get(Res);
798}
799
800RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
801                                                    QualType ExprType) {
802  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
803}
804
805RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
806                                               QualType ExprType) {
807  return EmitObjCPropertyGet(LV.getKVCRefExpr());
808}
809
810// If this is a reference to a subset of the elements of a vector, create an
811// appropriate shufflevector.
812RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
813                                                         QualType ExprType) {
814  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
815                                        LV.isVolatileQualified(), "tmp");
816
817  const llvm::Constant *Elts = LV.getExtVectorElts();
818
819  // If the result of the expression is a non-vector type, we must be extracting
820  // a single element.  Just codegen as an extractelement.
821  const VectorType *ExprVT = ExprType->getAs<VectorType>();
822  if (!ExprVT) {
823    unsigned InIdx = getAccessedFieldNo(0, Elts);
824    llvm::Value *Elt = llvm::ConstantInt::get(
825                                      llvm::Type::getInt32Ty(VMContext), InIdx);
826    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
827  }
828
829  // Always use shuffle vector to try to retain the original program structure
830  unsigned NumResultElts = ExprVT->getNumElements();
831
832  llvm::SmallVector<llvm::Constant*, 4> Mask;
833  for (unsigned i = 0; i != NumResultElts; ++i) {
834    unsigned InIdx = getAccessedFieldNo(i, Elts);
835    Mask.push_back(llvm::ConstantInt::get(
836                                     llvm::Type::getInt32Ty(VMContext), InIdx));
837  }
838
839  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
840  Vec = Builder.CreateShuffleVector(Vec,
841                                    llvm::UndefValue::get(Vec->getType()),
842                                    MaskV, "tmp");
843  return RValue::get(Vec);
844}
845
846
847
848/// EmitStoreThroughLValue - Store the specified rvalue into the specified
849/// lvalue, where both are guaranteed to the have the same type, and that type
850/// is 'Ty'.
851void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
852                                             QualType Ty) {
853  if (!Dst.isSimple()) {
854    if (Dst.isVectorElt()) {
855      // Read/modify/write the vector, inserting the new element.
856      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
857                                            Dst.isVolatileQualified(), "tmp");
858      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
859                                        Dst.getVectorIdx(), "vecins");
860      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
861      return;
862    }
863
864    // If this is an update of extended vector elements, insert them as
865    // appropriate.
866    if (Dst.isExtVectorElt())
867      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
868
869    if (Dst.isBitField())
870      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
871
872    if (Dst.isPropertyRef())
873      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
874
875    assert(Dst.isKVCRef() && "Unknown LValue type");
876    return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
877  }
878
879  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
880    // load of a __weak object.
881    llvm::Value *LvalueDst = Dst.getAddress();
882    llvm::Value *src = Src.getScalarVal();
883     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
884    return;
885  }
886
887  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
888    // load of a __strong object.
889    llvm::Value *LvalueDst = Dst.getAddress();
890    llvm::Value *src = Src.getScalarVal();
891    if (Dst.isObjCIvar()) {
892      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
893      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
894      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
895      llvm::Value *dst = RHS;
896      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
897      llvm::Value *LHS =
898        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
899      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
900      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
901                                              BytesBetween);
902    } else if (Dst.isGlobalObjCRef())
903      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
904    else
905      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
906    return;
907  }
908
909  assert(Src.isScalar() && "Can't emit an agg store with this method");
910  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
911                    Dst.isVolatileQualified(), Ty);
912}
913
914void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
915                                                     QualType Ty,
916                                                     llvm::Value **Result) {
917  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
918
919  // Get the output type.
920  const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
921  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
922
923  // Get the source value, truncated to the width of the bit-field.
924  llvm::Value *SrcVal = Src.getScalarVal();
925
926  if (Ty->isBooleanType())
927    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
928
929  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
930                                                                Info.getSize()),
931                             "bf.value");
932
933  // Return the new value of the bit-field, if requested.
934  if (Result) {
935    // Cast back to the proper type for result.
936    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
937    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
938                                                   "bf.reload.val");
939
940    // Sign extend if necessary.
941    if (Info.isSigned()) {
942      unsigned ExtraBits = ResSizeInBits - Info.getSize();
943      if (ExtraBits)
944        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
945                                       ExtraBits, "bf.reload.sext");
946    }
947
948    *Result = ReloadVal;
949  }
950
951  // Iterate over the components, writing each piece to memory.
952  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
953    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
954
955    // Get the field pointer.
956    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
957
958    // Only offset by the field index if used, so that incoming values are not
959    // required to be structures.
960    if (AI.FieldIndex)
961      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
962
963    // Offset by the byte offset, if used.
964    if (AI.FieldByteOffset) {
965      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
966      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
967      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
968    }
969
970    // Cast to the access type.
971    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
972                                                     Ty.getAddressSpace());
973    Ptr = Builder.CreateBitCast(Ptr, PTy);
974
975    // Extract the piece of the bit-field value to write in this access, limited
976    // to the values that are part of this access.
977    llvm::Value *Val = SrcVal;
978    if (AI.TargetBitOffset)
979      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
980    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
981                                                            AI.TargetBitWidth));
982
983    // Extend or truncate to the access size.
984    const llvm::Type *AccessLTy =
985      llvm::Type::getIntNTy(VMContext, AI.AccessWidth);
986    if (ResSizeInBits < AI.AccessWidth)
987      Val = Builder.CreateZExt(Val, AccessLTy);
988    else if (ResSizeInBits > AI.AccessWidth)
989      Val = Builder.CreateTrunc(Val, AccessLTy);
990
991    // Shift into the position in memory.
992    if (AI.FieldBitStart)
993      Val = Builder.CreateShl(Val, AI.FieldBitStart);
994
995    // If necessary, load and OR in bits that are outside of the bit-field.
996    if (AI.TargetBitWidth != AI.AccessWidth) {
997      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
998      if (AI.AccessAlignment)
999        Load->setAlignment(AI.AccessAlignment);
1000
1001      // Compute the mask for zeroing the bits that are part of the bit-field.
1002      llvm::APInt InvMask =
1003        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
1004                                 AI.FieldBitStart + AI.TargetBitWidth);
1005
1006      // Apply the mask and OR in to the value to write.
1007      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
1008    }
1009
1010    // Write the value.
1011    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
1012                                                 Dst.isVolatileQualified());
1013    if (AI.AccessAlignment)
1014      Store->setAlignment(AI.AccessAlignment);
1015  }
1016}
1017
1018void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
1019                                                        LValue Dst,
1020                                                        QualType Ty) {
1021  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
1022}
1023
1024void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
1025                                                   LValue Dst,
1026                                                   QualType Ty) {
1027  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
1028}
1029
1030void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1031                                                               LValue Dst,
1032                                                               QualType Ty) {
1033  // This access turns into a read/modify/write of the vector.  Load the input
1034  // value now.
1035  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
1036                                        Dst.isVolatileQualified(), "tmp");
1037  const llvm::Constant *Elts = Dst.getExtVectorElts();
1038
1039  llvm::Value *SrcVal = Src.getScalarVal();
1040
1041  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
1042    unsigned NumSrcElts = VTy->getNumElements();
1043    unsigned NumDstElts =
1044       cast<llvm::VectorType>(Vec->getType())->getNumElements();
1045    if (NumDstElts == NumSrcElts) {
1046      // Use shuffle vector is the src and destination are the same number of
1047      // elements and restore the vector mask since it is on the side it will be
1048      // stored.
1049      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1050      for (unsigned i = 0; i != NumSrcElts; ++i) {
1051        unsigned InIdx = getAccessedFieldNo(i, Elts);
1052        Mask[InIdx] = llvm::ConstantInt::get(
1053                                          llvm::Type::getInt32Ty(VMContext), i);
1054      }
1055
1056      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
1057      Vec = Builder.CreateShuffleVector(SrcVal,
1058                                        llvm::UndefValue::get(Vec->getType()),
1059                                        MaskV, "tmp");
1060    } else if (NumDstElts > NumSrcElts) {
1061      // Extended the source vector to the same length and then shuffle it
1062      // into the destination.
1063      // FIXME: since we're shuffling with undef, can we just use the indices
1064      //        into that?  This could be simpler.
1065      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1066      const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1067      unsigned i;
1068      for (i = 0; i != NumSrcElts; ++i)
1069        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1070      for (; i != NumDstElts; ++i)
1071        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1072      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
1073                                                        ExtMask.size());
1074      llvm::Value *ExtSrcVal =
1075        Builder.CreateShuffleVector(SrcVal,
1076                                    llvm::UndefValue::get(SrcVal->getType()),
1077                                    ExtMaskV, "tmp");
1078      // build identity
1079      llvm::SmallVector<llvm::Constant*, 4> Mask;
1080      for (unsigned i = 0; i != NumDstElts; ++i)
1081        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1082
1083      // modify when what gets shuffled in
1084      for (unsigned i = 0; i != NumSrcElts; ++i) {
1085        unsigned Idx = getAccessedFieldNo(i, Elts);
1086        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
1087      }
1088      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
1089      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
1090    } else {
1091      // We should never shorten the vector
1092      assert(0 && "unexpected shorten vector length");
1093    }
1094  } else {
1095    // If the Src is a scalar (not a vector) it must be updating one element.
1096    unsigned InIdx = getAccessedFieldNo(0, Elts);
1097    const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1098    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
1099    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
1100  }
1101
1102  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
1103}
1104
1105// setObjCGCLValueClass - sets class of he lvalue for the purpose of
1106// generating write-barries API. It is currently a global, ivar,
1107// or neither.
1108static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1109                                 LValue &LV) {
1110  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
1111    return;
1112
1113  if (isa<ObjCIvarRefExpr>(E)) {
1114    LV.SetObjCIvar(LV, true);
1115    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
1116    LV.setBaseIvarExp(Exp->getBase());
1117    LV.SetObjCArray(LV, E->getType()->isArrayType());
1118    return;
1119  }
1120
1121  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
1122    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1123      if ((VD->isBlockVarDecl() && !VD->hasLocalStorage()) ||
1124          VD->isFileVarDecl())
1125        LV.SetGlobalObjCRef(LV, true);
1126    }
1127    LV.SetObjCArray(LV, E->getType()->isArrayType());
1128    return;
1129  }
1130
1131  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
1132    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1133    return;
1134  }
1135
1136  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
1137    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1138    if (LV.isObjCIvar()) {
1139      // If cast is to a structure pointer, follow gcc's behavior and make it
1140      // a non-ivar write-barrier.
1141      QualType ExpTy = E->getType();
1142      if (ExpTy->isPointerType())
1143        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1144      if (ExpTy->isRecordType())
1145        LV.SetObjCIvar(LV, false);
1146    }
1147    return;
1148  }
1149  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1150    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1151    return;
1152  }
1153
1154  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1155    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1156    return;
1157  }
1158
1159  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1160    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1161    if (LV.isObjCIvar() && !LV.isObjCArray())
1162      // Using array syntax to assigning to what an ivar points to is not
1163      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1164      LV.SetObjCIvar(LV, false);
1165    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1166      // Using array syntax to assigning to what global points to is not
1167      // same as assigning to the global itself. {id *G;} G[i] = 0;
1168      LV.SetGlobalObjCRef(LV, false);
1169    return;
1170  }
1171
1172  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1173    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1174    // We don't know if member is an 'ivar', but this flag is looked at
1175    // only in the context of LV.isObjCIvar().
1176    LV.SetObjCArray(LV, E->getType()->isArrayType());
1177    return;
1178  }
1179}
1180
1181static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1182                                      const Expr *E, const VarDecl *VD) {
1183  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1184         "Var decl must have external storage or be a file var decl!");
1185
1186  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1187  if (VD->getType()->isReferenceType())
1188    V = CGF.Builder.CreateLoad(V, "tmp");
1189  LValue LV = LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
1190  setObjCGCLValueClass(CGF.getContext(), E, LV);
1191  return LV;
1192}
1193
1194static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1195                                      const Expr *E, const FunctionDecl *FD) {
1196  llvm::Value* V = CGF.CGM.GetAddrOfFunction(FD);
1197  if (!FD->hasPrototype()) {
1198    if (const FunctionProtoType *Proto =
1199            FD->getType()->getAs<FunctionProtoType>()) {
1200      // Ugly case: for a K&R-style definition, the type of the definition
1201      // isn't the same as the type of a use.  Correct for this with a
1202      // bitcast.
1203      QualType NoProtoType =
1204          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1205      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1206      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1207    }
1208  }
1209  return LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
1210}
1211
1212LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1213  const NamedDecl *ND = E->getDecl();
1214
1215  if (ND->hasAttr<WeakRefAttr>()) {
1216    const ValueDecl* VD = cast<ValueDecl>(ND);
1217    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1218
1219    Qualifiers Quals = MakeQualifiers(E->getType());
1220    LValue LV = LValue::MakeAddr(Aliasee, Quals);
1221
1222    return LV;
1223  }
1224
1225  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1226
1227    // Check if this is a global variable.
1228    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1229      return EmitGlobalVarDeclLValue(*this, E, VD);
1230
1231    bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
1232
1233    llvm::Value *V = LocalDeclMap[VD];
1234    if (!V && getContext().getLangOptions().CPlusPlus &&
1235        VD->isStaticLocal())
1236      V = CGM.getStaticLocalDeclAddress(VD);
1237    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1238
1239    Qualifiers Quals = MakeQualifiers(E->getType());
1240    // local variables do not get their gc attribute set.
1241    // local static?
1242    if (NonGCable) Quals.removeObjCGCAttr();
1243
1244    if (VD->hasAttr<BlocksAttr>()) {
1245      V = Builder.CreateStructGEP(V, 1, "forwarding");
1246      V = Builder.CreateLoad(V);
1247      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
1248                                  VD->getNameAsString());
1249    }
1250    if (VD->getType()->isReferenceType())
1251      V = Builder.CreateLoad(V, "tmp");
1252    LValue LV = LValue::MakeAddr(V, Quals);
1253    LValue::SetObjCNonGC(LV, NonGCable);
1254    setObjCGCLValueClass(getContext(), E, LV);
1255    return LV;
1256  }
1257
1258  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1259    return EmitFunctionDeclLValue(*this, E, FD);
1260
1261  // FIXME: the qualifier check does not seem sufficient here
1262  if (E->getQualifier()) {
1263    const FieldDecl *FD = cast<FieldDecl>(ND);
1264    llvm::Value *V = CGM.EmitPointerToDataMember(FD);
1265
1266    return LValue::MakeAddr(V, MakeQualifiers(FD->getType()));
1267  }
1268
1269  assert(false && "Unhandled DeclRefExpr");
1270
1271  // an invalid LValue, but the assert will
1272  // ensure that this point is never reached.
1273  return LValue();
1274}
1275
1276LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1277  return LValue::MakeAddr(GetAddrOfBlockDecl(E), MakeQualifiers(E->getType()));
1278}
1279
1280LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1281  // __extension__ doesn't affect lvalue-ness.
1282  if (E->getOpcode() == UnaryOperator::Extension)
1283    return EmitLValue(E->getSubExpr());
1284
1285  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1286  switch (E->getOpcode()) {
1287  default: assert(0 && "Unknown unary operator lvalue!");
1288  case UnaryOperator::Deref: {
1289    QualType T = E->getSubExpr()->getType()->getPointeeType();
1290    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1291
1292    Qualifiers Quals = MakeQualifiers(T);
1293    Quals.setAddressSpace(ExprTy.getAddressSpace());
1294
1295    LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), Quals);
1296    // We should not generate __weak write barrier on indirect reference
1297    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1298    // But, we continue to generate __strong write barrier on indirect write
1299    // into a pointer to object.
1300    if (getContext().getLangOptions().ObjC1 &&
1301        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1302        LV.isObjCWeak())
1303      LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1304    return LV;
1305  }
1306  case UnaryOperator::Real:
1307  case UnaryOperator::Imag: {
1308    LValue LV = EmitLValue(E->getSubExpr());
1309    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
1310    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
1311                                                    Idx, "idx"),
1312                            MakeQualifiers(ExprTy));
1313  }
1314  case UnaryOperator::PreInc:
1315  case UnaryOperator::PreDec: {
1316    LValue LV = EmitLValue(E->getSubExpr());
1317    bool isInc = E->getOpcode() == UnaryOperator::PreInc;
1318
1319    if (E->getType()->isAnyComplexType())
1320      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1321    else
1322      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1323    return LV;
1324  }
1325  }
1326}
1327
1328LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1329  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E),
1330                          Qualifiers());
1331}
1332
1333LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1334  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1335                          Qualifiers());
1336}
1337
1338
1339LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
1340  std::string GlobalVarName;
1341
1342  switch (Type) {
1343  default: assert(0 && "Invalid type");
1344  case PredefinedExpr::Func:
1345    GlobalVarName = "__func__.";
1346    break;
1347  case PredefinedExpr::Function:
1348    GlobalVarName = "__FUNCTION__.";
1349    break;
1350  case PredefinedExpr::PrettyFunction:
1351    GlobalVarName = "__PRETTY_FUNCTION__.";
1352    break;
1353  }
1354
1355  llvm::StringRef FnName = CurFn->getName();
1356  if (FnName.startswith("\01"))
1357    FnName = FnName.substr(1);
1358  GlobalVarName += FnName;
1359
1360  std::string FunctionName =
1361    PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurCodeDecl);
1362
1363  llvm::Constant *C =
1364    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1365  return LValue::MakeAddr(C, Qualifiers());
1366}
1367
1368LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1369  switch (E->getIdentType()) {
1370  default:
1371    return EmitUnsupportedLValue(E, "predefined expression");
1372  case PredefinedExpr::Func:
1373  case PredefinedExpr::Function:
1374  case PredefinedExpr::PrettyFunction:
1375    return EmitPredefinedFunctionName(E->getIdentType());
1376  }
1377}
1378
1379llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1380  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1381
1382  // If we are not optimzing, don't collapse all calls to trap in the function
1383  // to the same call, that way, in the debugger they can see which operation
1384  // did in fact fail.  If we are optimizing, we collpase all call to trap down
1385  // to just one per function to save on codesize.
1386  if (GCO.OptimizationLevel
1387      && TrapBB)
1388    return TrapBB;
1389
1390  llvm::BasicBlock *Cont = 0;
1391  if (HaveInsertPoint()) {
1392    Cont = createBasicBlock("cont");
1393    EmitBranch(Cont);
1394  }
1395  TrapBB = createBasicBlock("trap");
1396  EmitBlock(TrapBB);
1397
1398  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1399  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1400  TrapCall->setDoesNotReturn();
1401  TrapCall->setDoesNotThrow();
1402  Builder.CreateUnreachable();
1403
1404  if (Cont)
1405    EmitBlock(Cont);
1406  return TrapBB;
1407}
1408
1409LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1410  // The index must always be an integer, which is not an aggregate.  Emit it.
1411  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1412  QualType IdxTy  = E->getIdx()->getType();
1413  bool IdxSigned = IdxTy->isSignedIntegerType();
1414
1415  // If the base is a vector type, then we are forming a vector element lvalue
1416  // with this subscript.
1417  if (E->getBase()->getType()->isVectorType()) {
1418    // Emit the vector as an lvalue to get its address.
1419    LValue LHS = EmitLValue(E->getBase());
1420    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1421    Idx = Builder.CreateIntCast(Idx,
1422                          llvm::Type::getInt32Ty(VMContext), IdxSigned, "vidx");
1423    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1424                                 E->getBase()->getType().getCVRQualifiers());
1425  }
1426
1427  // The base must be a pointer, which is not an aggregate.  Emit it.
1428  llvm::Value *Base = EmitScalarExpr(E->getBase());
1429
1430  // Extend or truncate the index type to 32 or 64-bits.
1431  unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
1432  if (IdxBitwidth != LLVMPointerWidth)
1433    Idx = Builder.CreateIntCast(Idx,
1434                            llvm::IntegerType::get(VMContext, LLVMPointerWidth),
1435                                IdxSigned, "idxprom");
1436
1437  // FIXME: As llvm implements the object size checking, this can come out.
1438  if (CatchUndefined) {
1439    if (const ImplicitCastExpr *ICE=dyn_cast<ImplicitCastExpr>(E->getBase())) {
1440      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1441        if (ICE->getCastKind() == CastExpr::CK_ArrayToPointerDecay) {
1442          if (const ConstantArrayType *CAT
1443              = getContext().getAsConstantArrayType(DRE->getType())) {
1444            llvm::APInt Size = CAT->getSize();
1445            llvm::BasicBlock *Cont = createBasicBlock("cont");
1446            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1447                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1448                                 Cont, getTrapBB());
1449            EmitBlock(Cont);
1450          }
1451        }
1452      }
1453    }
1454  }
1455
1456  // We know that the pointer points to a type of the correct size, unless the
1457  // size is a VLA or Objective-C interface.
1458  llvm::Value *Address = 0;
1459  if (const VariableArrayType *VAT =
1460        getContext().getAsVariableArrayType(E->getType())) {
1461    llvm::Value *VLASize = GetVLASize(VAT);
1462
1463    Idx = Builder.CreateMul(Idx, VLASize);
1464
1465    QualType BaseType = getContext().getBaseElementType(VAT);
1466
1467    CharUnits BaseTypeSize = getContext().getTypeSizeInChars(BaseType);
1468    Idx = Builder.CreateUDiv(Idx,
1469                             llvm::ConstantInt::get(Idx->getType(),
1470                                 BaseTypeSize.getQuantity()));
1471    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1472  } else if (const ObjCObjectType *OIT =
1473               E->getType()->getAs<ObjCObjectType>()) {
1474    llvm::Value *InterfaceSize =
1475      llvm::ConstantInt::get(Idx->getType(),
1476          getContext().getTypeSizeInChars(OIT).getQuantity());
1477
1478    Idx = Builder.CreateMul(Idx, InterfaceSize);
1479
1480    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1481    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1482                                Idx, "arrayidx");
1483    Address = Builder.CreateBitCast(Address, Base->getType());
1484  } else {
1485    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1486  }
1487
1488  QualType T = E->getBase()->getType()->getPointeeType();
1489  assert(!T.isNull() &&
1490         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1491
1492  Qualifiers Quals = MakeQualifiers(T);
1493  Quals.setAddressSpace(E->getBase()->getType().getAddressSpace());
1494
1495  LValue LV = LValue::MakeAddr(Address, Quals);
1496  if (getContext().getLangOptions().ObjC1 &&
1497      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1498    LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1499    setObjCGCLValueClass(getContext(), E, LV);
1500  }
1501  return LV;
1502}
1503
1504static
1505llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1506                                       llvm::SmallVector<unsigned, 4> &Elts) {
1507  llvm::SmallVector<llvm::Constant*, 4> CElts;
1508
1509  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1510    CElts.push_back(llvm::ConstantInt::get(
1511                                   llvm::Type::getInt32Ty(VMContext), Elts[i]));
1512
1513  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1514}
1515
1516LValue CodeGenFunction::
1517EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1518  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1519
1520  // Emit the base vector as an l-value.
1521  LValue Base;
1522
1523  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1524  if (E->isArrow()) {
1525    // If it is a pointer to a vector, emit the address and form an lvalue with
1526    // it.
1527    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1528    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1529    Qualifiers Quals = MakeQualifiers(PT->getPointeeType());
1530    Quals.removeObjCGCAttr();
1531    Base = LValue::MakeAddr(Ptr, Quals);
1532  } else if (E->getBase()->isLvalue(getContext()) == Expr::LV_Valid) {
1533    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1534    // emit the base as an lvalue.
1535    assert(E->getBase()->getType()->isVectorType());
1536    Base = EmitLValue(E->getBase());
1537  } else {
1538    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1539    assert(E->getBase()->getType()->getAs<VectorType>() &&
1540           "Result must be a vector");
1541    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1542
1543    // Store the vector to memory (because LValue wants an address).
1544    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1545    Builder.CreateStore(Vec, VecMem);
1546    Base = LValue::MakeAddr(VecMem, Qualifiers());
1547  }
1548
1549  // Encode the element access list into a vector of unsigned indices.
1550  llvm::SmallVector<unsigned, 4> Indices;
1551  E->getEncodedElementAccess(Indices);
1552
1553  if (Base.isSimple()) {
1554    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1555    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1556                                    Base.getVRQualifiers());
1557  }
1558  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1559
1560  llvm::Constant *BaseElts = Base.getExtVectorElts();
1561  llvm::SmallVector<llvm::Constant *, 4> CElts;
1562
1563  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1564    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1565      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1566    else
1567      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1568  }
1569  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1570  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1571                                  Base.getVRQualifiers());
1572}
1573
1574LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1575  bool isNonGC = false;
1576  Expr *BaseExpr = E->getBase();
1577  llvm::Value *BaseValue = NULL;
1578  Qualifiers BaseQuals;
1579
1580  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1581  if (E->isArrow()) {
1582    BaseValue = EmitScalarExpr(BaseExpr);
1583    const PointerType *PTy =
1584      BaseExpr->getType()->getAs<PointerType>();
1585    BaseQuals = PTy->getPointeeType().getQualifiers();
1586  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1587             isa<ObjCImplicitSetterGetterRefExpr>(
1588               BaseExpr->IgnoreParens())) {
1589    RValue RV = EmitObjCPropertyGet(BaseExpr);
1590    BaseValue = RV.getAggregateAddr();
1591    BaseQuals = BaseExpr->getType().getQualifiers();
1592  } else {
1593    LValue BaseLV = EmitLValue(BaseExpr);
1594    if (BaseLV.isNonGC())
1595      isNonGC = true;
1596    // FIXME: this isn't right for bitfields.
1597    BaseValue = BaseLV.getAddress();
1598    QualType BaseTy = BaseExpr->getType();
1599    BaseQuals = BaseTy.getQualifiers();
1600  }
1601
1602  NamedDecl *ND = E->getMemberDecl();
1603  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1604    LValue LV = EmitLValueForField(BaseValue, Field,
1605                                   BaseQuals.getCVRQualifiers());
1606    LValue::SetObjCNonGC(LV, isNonGC);
1607    setObjCGCLValueClass(getContext(), E, LV);
1608    return LV;
1609  }
1610
1611  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1612    return EmitGlobalVarDeclLValue(*this, E, VD);
1613
1614  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1615    return EmitFunctionDeclLValue(*this, E, FD);
1616
1617  assert(false && "Unhandled member declaration!");
1618  return LValue();
1619}
1620
1621LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
1622                                              const FieldDecl* Field,
1623                                              unsigned CVRQualifiers) {
1624  const CGRecordLayout &RL =
1625    CGM.getTypes().getCGRecordLayout(Field->getParent());
1626  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1627  return LValue::MakeBitfield(BaseValue, Info,
1628                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1629}
1630
1631/// EmitLValueForAnonRecordField - Given that the field is a member of
1632/// an anonymous struct or union buried inside a record, and given
1633/// that the base value is a pointer to the enclosing record, derive
1634/// an lvalue for the ultimate field.
1635LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1636                                                     const FieldDecl *Field,
1637                                                     unsigned CVRQualifiers) {
1638  llvm::SmallVector<const FieldDecl *, 8> Path;
1639  Path.push_back(Field);
1640
1641  while (Field->getParent()->isAnonymousStructOrUnion()) {
1642    const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
1643    if (!isa<FieldDecl>(VD)) break;
1644    Field = cast<FieldDecl>(VD);
1645    Path.push_back(Field);
1646  }
1647
1648  llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
1649    I = Path.rbegin(), E = Path.rend();
1650  while (true) {
1651    LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
1652    if (++I == E) return LV;
1653
1654    assert(LV.isSimple());
1655    BaseValue = LV.getAddress();
1656    CVRQualifiers |= LV.getVRQualifiers();
1657  }
1658}
1659
1660LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
1661                                           const FieldDecl* Field,
1662                                           unsigned CVRQualifiers) {
1663  if (Field->isBitField())
1664    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1665
1666  const CGRecordLayout &RL =
1667    CGM.getTypes().getCGRecordLayout(Field->getParent());
1668  unsigned idx = RL.getLLVMFieldNo(Field);
1669  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1670
1671  // Match union field type.
1672  if (Field->getParent()->isUnion()) {
1673    const llvm::Type *FieldTy =
1674      CGM.getTypes().ConvertTypeForMem(Field->getType());
1675    const llvm::PointerType * BaseTy =
1676      cast<llvm::PointerType>(BaseValue->getType());
1677    unsigned AS = BaseTy->getAddressSpace();
1678    V = Builder.CreateBitCast(V,
1679                              llvm::PointerType::get(FieldTy, AS),
1680                              "tmp");
1681  }
1682  if (Field->getType()->isReferenceType())
1683    V = Builder.CreateLoad(V, "tmp");
1684
1685  Qualifiers Quals = MakeQualifiers(Field->getType());
1686  Quals.addCVRQualifiers(CVRQualifiers);
1687  // __weak attribute on a field is ignored.
1688  if (Quals.getObjCGCAttr() == Qualifiers::Weak)
1689    Quals.removeObjCGCAttr();
1690
1691  return LValue::MakeAddr(V, Quals);
1692}
1693
1694LValue
1695CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value* BaseValue,
1696                                                  const FieldDecl* Field,
1697                                                  unsigned CVRQualifiers) {
1698  QualType FieldType = Field->getType();
1699
1700  if (!FieldType->isReferenceType())
1701    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1702
1703  const CGRecordLayout &RL =
1704    CGM.getTypes().getCGRecordLayout(Field->getParent());
1705  unsigned idx = RL.getLLVMFieldNo(Field);
1706  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1707
1708  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1709
1710  return LValue::MakeAddr(V, MakeQualifiers(FieldType));
1711}
1712
1713LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
1714  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1715  const Expr* InitExpr = E->getInitializer();
1716  LValue Result = LValue::MakeAddr(DeclPtr, MakeQualifiers(E->getType()));
1717
1718  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false);
1719
1720  return Result;
1721}
1722
1723LValue
1724CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
1725  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1726    if (int Cond = ConstantFoldsToSimpleInteger(E->getCond())) {
1727      Expr *Live = Cond == 1 ? E->getLHS() : E->getRHS();
1728      if (Live)
1729        return EmitLValue(Live);
1730    }
1731
1732    if (!E->getLHS())
1733      return EmitUnsupportedLValue(E, "conditional operator with missing LHS");
1734
1735    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1736    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1737    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1738
1739    EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1740
1741    // Any temporaries created here are conditional.
1742    BeginConditionalBranch();
1743    EmitBlock(LHSBlock);
1744    LValue LHS = EmitLValue(E->getLHS());
1745    EndConditionalBranch();
1746
1747    if (!LHS.isSimple())
1748      return EmitUnsupportedLValue(E, "conditional operator");
1749
1750    // FIXME: We shouldn't need an alloca for this.
1751    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1752    Builder.CreateStore(LHS.getAddress(), Temp);
1753    EmitBranch(ContBlock);
1754
1755    // Any temporaries created here are conditional.
1756    BeginConditionalBranch();
1757    EmitBlock(RHSBlock);
1758    LValue RHS = EmitLValue(E->getRHS());
1759    EndConditionalBranch();
1760    if (!RHS.isSimple())
1761      return EmitUnsupportedLValue(E, "conditional operator");
1762
1763    Builder.CreateStore(RHS.getAddress(), Temp);
1764    EmitBranch(ContBlock);
1765
1766    EmitBlock(ContBlock);
1767
1768    Temp = Builder.CreateLoad(Temp, "lv");
1769    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1770  }
1771
1772  // ?: here should be an aggregate.
1773  assert((hasAggregateLLVMType(E->getType()) &&
1774          !E->getType()->isAnyComplexType()) &&
1775         "Unexpected conditional operator!");
1776
1777  return EmitAggExprToLValue(E);
1778}
1779
1780/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1781/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1782/// otherwise if a cast is needed by the code generator in an lvalue context,
1783/// then it must mean that we need the address of an aggregate in order to
1784/// access one of its fields.  This can happen for all the reasons that casts
1785/// are permitted with aggregate result, including noop aggregate casts, and
1786/// cast from scalar to union.
1787LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1788  switch (E->getCastKind()) {
1789  default:
1790    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1791
1792  case CastExpr::CK_Dynamic: {
1793    LValue LV = EmitLValue(E->getSubExpr());
1794    llvm::Value *V = LV.getAddress();
1795    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1796    return LValue::MakeAddr(EmitDynamicCast(V, DCE),
1797                            MakeQualifiers(E->getType()));
1798  }
1799
1800  case CastExpr::CK_NoOp: {
1801    LValue LV = EmitLValue(E->getSubExpr());
1802    if (LV.isPropertyRef()) {
1803      QualType QT = E->getSubExpr()->getType();
1804      RValue RV = EmitLoadOfPropertyRefLValue(LV, QT);
1805      assert(!RV.isScalar() && "EmitCastLValue - scalar cast of property ref");
1806      llvm::Value *V = RV.getAggregateAddr();
1807      return LValue::MakeAddr(V, MakeQualifiers(QT));
1808    }
1809    return LV;
1810  }
1811  case CastExpr::CK_ConstructorConversion:
1812  case CastExpr::CK_UserDefinedConversion:
1813  case CastExpr::CK_AnyPointerToObjCPointerCast:
1814    return EmitLValue(E->getSubExpr());
1815
1816  case CastExpr::CK_UncheckedDerivedToBase:
1817  case CastExpr::CK_DerivedToBase: {
1818    const RecordType *DerivedClassTy =
1819      E->getSubExpr()->getType()->getAs<RecordType>();
1820    CXXRecordDecl *DerivedClassDecl =
1821      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1822
1823    LValue LV = EmitLValue(E->getSubExpr());
1824    llvm::Value *This;
1825    if (LV.isPropertyRef()) {
1826      RValue RV = EmitLoadOfPropertyRefLValue(LV, E->getSubExpr()->getType());
1827      assert (!RV.isScalar() && "EmitCastLValue");
1828      This = RV.getAggregateAddr();
1829    }
1830    else
1831      This = LV.getAddress();
1832
1833    // Perform the derived-to-base conversion
1834    llvm::Value *Base =
1835      GetAddressOfBaseClass(This, DerivedClassDecl,
1836                            E->getBasePath(), /*NullCheckValue=*/false);
1837
1838    return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
1839  }
1840  case CastExpr::CK_ToUnion:
1841    return EmitAggExprToLValue(E);
1842  case CastExpr::CK_BaseToDerived: {
1843    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1844    CXXRecordDecl *DerivedClassDecl =
1845      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1846
1847    LValue LV = EmitLValue(E->getSubExpr());
1848
1849    // Perform the base-to-derived conversion
1850    llvm::Value *Derived =
1851      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1852                               E->getBasePath(),/*NullCheckValue=*/false);
1853
1854    return LValue::MakeAddr(Derived, MakeQualifiers(E->getType()));
1855  }
1856  case CastExpr::CK_BitCast: {
1857    // This must be a reinterpret_cast (or c-style equivalent).
1858    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1859
1860    LValue LV = EmitLValue(E->getSubExpr());
1861    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1862                                           ConvertType(CE->getTypeAsWritten()));
1863    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1864  }
1865  }
1866}
1867
1868LValue CodeGenFunction::EmitNullInitializationLValue(
1869                                              const CXXZeroInitValueExpr *E) {
1870  QualType Ty = E->getType();
1871  LValue LV = LValue::MakeAddr(CreateMemTemp(Ty), MakeQualifiers(Ty));
1872  EmitNullInitialization(LV.getAddress(), Ty);
1873  return LV;
1874}
1875
1876//===--------------------------------------------------------------------===//
1877//                             Expression Emission
1878//===--------------------------------------------------------------------===//
1879
1880
1881RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
1882                                     ReturnValueSlot ReturnValue) {
1883  // Builtins never have block type.
1884  if (E->getCallee()->getType()->isBlockPointerType())
1885    return EmitBlockCallExpr(E, ReturnValue);
1886
1887  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1888    return EmitCXXMemberCallExpr(CE, ReturnValue);
1889
1890  const Decl *TargetDecl = 0;
1891  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1892    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1893      TargetDecl = DRE->getDecl();
1894      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1895        if (unsigned builtinID = FD->getBuiltinID())
1896          return EmitBuiltinExpr(FD, builtinID, E);
1897    }
1898  }
1899
1900  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1901    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1902      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
1903
1904  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1905    // C++ [expr.pseudo]p1:
1906    //   The result shall only be used as the operand for the function call
1907    //   operator (), and the result of such a call has type void. The only
1908    //   effect is the evaluation of the postfix-expression before the dot or
1909    //   arrow.
1910    EmitScalarExpr(E->getCallee());
1911    return RValue::get(0);
1912  }
1913
1914  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1915  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
1916                  E->arg_begin(), E->arg_end(), TargetDecl);
1917}
1918
1919LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1920  // Comma expressions just emit their LHS then their RHS as an l-value.
1921  if (E->getOpcode() == BinaryOperator::Comma) {
1922    EmitAnyExpr(E->getLHS());
1923    EnsureInsertPoint();
1924    return EmitLValue(E->getRHS());
1925  }
1926
1927  if (E->getOpcode() == BinaryOperator::PtrMemD ||
1928      E->getOpcode() == BinaryOperator::PtrMemI)
1929    return EmitPointerToDataMemberBinaryExpr(E);
1930
1931  // Can only get l-value for binary operator expressions which are a
1932  // simple assignment of aggregate type.
1933  if (E->getOpcode() != BinaryOperator::Assign)
1934    return EmitUnsupportedLValue(E, "binary l-value expression");
1935
1936  if (!hasAggregateLLVMType(E->getType())) {
1937    // Emit the LHS as an l-value.
1938    LValue LV = EmitLValue(E->getLHS());
1939
1940    llvm::Value *RHS = EmitScalarExpr(E->getRHS());
1941    EmitStoreOfScalar(RHS, LV.getAddress(), LV.isVolatileQualified(),
1942                      E->getType());
1943    return LV;
1944  }
1945
1946  return EmitAggExprToLValue(E);
1947}
1948
1949LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
1950  RValue RV = EmitCallExpr(E);
1951
1952  if (!RV.isScalar())
1953    return LValue::MakeAddr(RV.getAggregateAddr(),MakeQualifiers(E->getType()));
1954
1955  assert(E->getCallReturnType()->isReferenceType() &&
1956         "Can't have a scalar return unless the return type is a "
1957         "reference type!");
1958
1959  return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
1960}
1961
1962LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
1963  // FIXME: This shouldn't require another copy.
1964  return EmitAggExprToLValue(E);
1965}
1966
1967LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
1968  llvm::Value *Temp = CreateMemTemp(E->getType(), "tmp");
1969  EmitCXXConstructExpr(Temp, E);
1970  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1971}
1972
1973LValue
1974CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
1975  llvm::Value *Temp = EmitCXXTypeidExpr(E);
1976  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1977}
1978
1979LValue
1980CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
1981  LValue LV = EmitLValue(E->getSubExpr());
1982  PushCXXTemporary(E->getTemporary(), LV.getAddress());
1983  return LV;
1984}
1985
1986LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
1987  RValue RV = EmitObjCMessageExpr(E);
1988
1989  if (!RV.isScalar())
1990    return LValue::MakeAddr(RV.getAggregateAddr(),
1991                            MakeQualifiers(E->getType()));
1992
1993  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
1994         "Can't have a scalar return unless the return type is a "
1995         "reference type!");
1996
1997  return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
1998}
1999
2000LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2001  llvm::Value *V =
2002    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2003  return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
2004}
2005
2006llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2007                                             const ObjCIvarDecl *Ivar) {
2008  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2009}
2010
2011LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2012                                          llvm::Value *BaseValue,
2013                                          const ObjCIvarDecl *Ivar,
2014                                          unsigned CVRQualifiers) {
2015  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2016                                                   Ivar, CVRQualifiers);
2017}
2018
2019LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2020  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2021  llvm::Value *BaseValue = 0;
2022  const Expr *BaseExpr = E->getBase();
2023  Qualifiers BaseQuals;
2024  QualType ObjectTy;
2025  if (E->isArrow()) {
2026    BaseValue = EmitScalarExpr(BaseExpr);
2027    ObjectTy = BaseExpr->getType()->getPointeeType();
2028    BaseQuals = ObjectTy.getQualifiers();
2029  } else {
2030    LValue BaseLV = EmitLValue(BaseExpr);
2031    // FIXME: this isn't right for bitfields.
2032    BaseValue = BaseLV.getAddress();
2033    ObjectTy = BaseExpr->getType();
2034    BaseQuals = ObjectTy.getQualifiers();
2035  }
2036
2037  LValue LV =
2038    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2039                      BaseQuals.getCVRQualifiers());
2040  setObjCGCLValueClass(getContext(), E, LV);
2041  return LV;
2042}
2043
2044LValue
2045CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
2046  // This is a special l-value that just issues sends when we load or store
2047  // through it.
2048  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
2049}
2050
2051LValue CodeGenFunction::EmitObjCKVCRefLValue(
2052                                const ObjCImplicitSetterGetterRefExpr *E) {
2053  // This is a special l-value that just issues sends when we load or store
2054  // through it.
2055  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
2056}
2057
2058LValue CodeGenFunction::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
2059  return EmitUnsupportedLValue(E, "use of super");
2060}
2061
2062LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2063  // Can only get l-value for message expression returning aggregate type
2064  RValue RV = EmitAnyExprToTemp(E);
2065  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
2066}
2067
2068RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2069                                 ReturnValueSlot ReturnValue,
2070                                 CallExpr::const_arg_iterator ArgBeg,
2071                                 CallExpr::const_arg_iterator ArgEnd,
2072                                 const Decl *TargetDecl) {
2073  // Get the actual function type. The callee type will always be a pointer to
2074  // function type or a block pointer type.
2075  assert(CalleeType->isFunctionPointerType() &&
2076         "Call must have function pointer type!");
2077
2078  CalleeType = getContext().getCanonicalType(CalleeType);
2079
2080  const FunctionType *FnType
2081    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2082  QualType ResultType = FnType->getResultType();
2083
2084  CallArgList Args;
2085  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2086
2087  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2088                  Callee, ReturnValue, Args, TargetDecl);
2089}
2090
2091LValue CodeGenFunction::
2092EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2093  llvm::Value *BaseV;
2094  if (E->getOpcode() == BinaryOperator::PtrMemI)
2095    BaseV = EmitScalarExpr(E->getLHS());
2096  else
2097    BaseV = EmitLValue(E->getLHS()).getAddress();
2098  const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
2099  BaseV = Builder.CreateBitCast(BaseV, i8Ty);
2100  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2101  llvm::Value *AddV = Builder.CreateInBoundsGEP(BaseV, OffsetV, "add.ptr");
2102
2103  QualType Ty = E->getRHS()->getType();
2104  Ty = Ty->getAs<MemberPointerType>()->getPointeeType();
2105
2106  const llvm::Type *PType = ConvertType(getContext().getPointerType(Ty));
2107  AddV = Builder.CreateBitCast(AddV, PType);
2108  return LValue::MakeAddr(AddV, MakeQualifiers(Ty));
2109}
2110
2111