CGExpr.cpp revision 9c6082fe89c61af697f017aa80937581cc2128d8 
1//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CodeGenModule.h"
16#include "CGCall.h"
17#include "CGCXXABI.h"
18#include "CGRecordLayout.h"
19#include "CGObjCRuntime.h"
20#include "clang/AST/ASTContext.h"
21#include "clang/AST/DeclObjC.h"
22#include "llvm/Intrinsics.h"
23#include "clang/Frontend/CodeGenOptions.h"
24#include "llvm/Target/TargetData.h"
25using namespace clang;
26using namespace CodeGen;
27
28//===--------------------------------------------------------------------===//
29//                        Miscellaneous Helper Methods
30//===--------------------------------------------------------------------===//
31
32llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
33  unsigned addressSpace =
34    cast<llvm::PointerType>(value->getType())->getAddressSpace();
35
36  const llvm::PointerType *destType = Int8PtrTy;
37  if (addressSpace)
38    destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
39
40  if (value->getType() == destType) return value;
41  return Builder.CreateBitCast(value, destType);
42}
43
44/// CreateTempAlloca - This creates a alloca and inserts it into the entry
45/// block.
46llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
47                                                    const llvm::Twine &Name) {
48  if (!Builder.isNamePreserving())
49    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
50  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
51}
52
53void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
54                                     llvm::Value *Init) {
55  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
56  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
57  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
58}
59
60llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
61                                                const llvm::Twine &Name) {
62  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
63  // FIXME: Should we prefer the preferred type alignment here?
64  CharUnits Align = getContext().getTypeAlignInChars(Ty);
65  Alloc->setAlignment(Align.getQuantity());
66  return Alloc;
67}
68
69llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
70                                                 const llvm::Twine &Name) {
71  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
72  // FIXME: Should we prefer the preferred type alignment here?
73  CharUnits Align = getContext().getTypeAlignInChars(Ty);
74  Alloc->setAlignment(Align.getQuantity());
75  return Alloc;
76}
77
78/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
79/// expression and compare the result against zero, returning an Int1Ty value.
80llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
81  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
82    llvm::Value *MemPtr = EmitScalarExpr(E);
83    return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
84  }
85
86  QualType BoolTy = getContext().BoolTy;
87  if (!E->getType()->isAnyComplexType())
88    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
89
90  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
91}
92
93/// EmitIgnoredExpr - Emit code to compute the specified expression,
94/// ignoring the result.
95void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
96  if (E->isRValue())
97    return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
98
99  // Just emit it as an l-value and drop the result.
100  EmitLValue(E);
101}
102
103/// EmitAnyExpr - Emit code to compute the specified expression which
104/// can have any type.  The result is returned as an RValue struct.
105/// If this is an aggregate expression, AggSlot indicates where the
106/// result should be returned.
107RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot,
108                                    bool IgnoreResult) {
109  if (!hasAggregateLLVMType(E->getType()))
110    return RValue::get(EmitScalarExpr(E, IgnoreResult));
111  else if (E->getType()->isAnyComplexType())
112    return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult));
113
114  EmitAggExpr(E, AggSlot, IgnoreResult);
115  return AggSlot.asRValue();
116}
117
118/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
119/// always be accessible even if no aggregate location is provided.
120RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
121  AggValueSlot AggSlot = AggValueSlot::ignored();
122
123  if (hasAggregateLLVMType(E->getType()) &&
124      !E->getType()->isAnyComplexType())
125    AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
126  return EmitAnyExpr(E, AggSlot);
127}
128
129/// EmitAnyExprToMem - Evaluate an expression into a given memory
130/// location.
131void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
132                                       llvm::Value *Location,
133                                       bool IsLocationVolatile,
134                                       bool IsInit) {
135  if (E->getType()->isComplexType())
136    EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
137  else if (hasAggregateLLVMType(E->getType()))
138    EmitAggExpr(E, AggValueSlot::forAddr(Location, IsLocationVolatile, IsInit));
139  else {
140    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
141    LValue LV = MakeAddrLValue(Location, E->getType());
142    EmitStoreThroughLValue(RV, LV, E->getType());
143  }
144}
145
146namespace {
147/// \brief An adjustment to be made to the temporary created when emitting a
148/// reference binding, which accesses a particular subobject of that temporary.
149  struct SubobjectAdjustment {
150    enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
151
152    union {
153      struct {
154        const CastExpr *BasePath;
155        const CXXRecordDecl *DerivedClass;
156      } DerivedToBase;
157
158      FieldDecl *Field;
159    };
160
161    SubobjectAdjustment(const CastExpr *BasePath,
162                        const CXXRecordDecl *DerivedClass)
163      : Kind(DerivedToBaseAdjustment) {
164      DerivedToBase.BasePath = BasePath;
165      DerivedToBase.DerivedClass = DerivedClass;
166    }
167
168    SubobjectAdjustment(FieldDecl *Field)
169      : Kind(FieldAdjustment) {
170      this->Field = Field;
171    }
172  };
173}
174
175static llvm::Value *
176CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
177                         const NamedDecl *InitializedDecl) {
178  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
179    if (VD->hasGlobalStorage()) {
180      llvm::SmallString<256> Name;
181      llvm::raw_svector_ostream Out(Name);
182      CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out);
183      Out.flush();
184
185      const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
186
187      // Create the reference temporary.
188      llvm::GlobalValue *RefTemp =
189        new llvm::GlobalVariable(CGF.CGM.getModule(),
190                                 RefTempTy, /*isConstant=*/false,
191                                 llvm::GlobalValue::InternalLinkage,
192                                 llvm::Constant::getNullValue(RefTempTy),
193                                 Name.str());
194      return RefTemp;
195    }
196  }
197
198  return CGF.CreateMemTemp(Type, "ref.tmp");
199}
200
201static llvm::Value *
202EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
203                            llvm::Value *&ReferenceTemporary,
204                            const CXXDestructorDecl *&ReferenceTemporaryDtor,
205                            const NamedDecl *InitializedDecl) {
206  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
207    E = DAE->getExpr();
208
209  if (const ExprWithCleanups *TE = dyn_cast<ExprWithCleanups>(E)) {
210    CodeGenFunction::RunCleanupsScope Scope(CGF);
211
212    return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
213                                       ReferenceTemporary,
214                                       ReferenceTemporaryDtor,
215                                       InitializedDecl);
216  }
217
218  RValue RV;
219  if (E->isGLValue()) {
220    // Emit the expression as an lvalue.
221    LValue LV = CGF.EmitLValue(E);
222    if (LV.isSimple())
223      return LV.getAddress();
224
225    // We have to load the lvalue.
226    RV = CGF.EmitLoadOfLValue(LV, E->getType());
227  } else {
228    QualType ResultTy = E->getType();
229
230    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
231    while (true) {
232      if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
233        E = PE->getSubExpr();
234        continue;
235      }
236
237      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
238        if ((CE->getCastKind() == CK_DerivedToBase ||
239             CE->getCastKind() == CK_UncheckedDerivedToBase) &&
240            E->getType()->isRecordType()) {
241          E = CE->getSubExpr();
242          CXXRecordDecl *Derived
243            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
244          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
245          continue;
246        }
247
248        if (CE->getCastKind() == CK_NoOp) {
249          E = CE->getSubExpr();
250          continue;
251        }
252      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
253        if (!ME->isArrow() && ME->getBase()->isRValue()) {
254          assert(ME->getBase()->getType()->isRecordType());
255          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
256            E = ME->getBase();
257            Adjustments.push_back(SubobjectAdjustment(Field));
258            continue;
259          }
260        }
261      }
262
263      if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
264        if (opaque->getType()->isRecordType())
265          return CGF.EmitOpaqueValueLValue(opaque).getAddress();
266
267      // Nothing changed.
268      break;
269    }
270
271    // Create a reference temporary if necessary.
272    AggValueSlot AggSlot = AggValueSlot::ignored();
273    if (CGF.hasAggregateLLVMType(E->getType()) &&
274        !E->getType()->isAnyComplexType()) {
275      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
276                                                    InitializedDecl);
277      AggSlot = AggValueSlot::forAddr(ReferenceTemporary, false,
278                                      InitializedDecl != 0);
279    }
280
281    RV = CGF.EmitAnyExpr(E, AggSlot);
282
283    if (InitializedDecl) {
284      // Get the destructor for the reference temporary.
285      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
286        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
287        if (!ClassDecl->hasTrivialDestructor())
288          ReferenceTemporaryDtor = ClassDecl->getDestructor();
289      }
290    }
291
292    // Check if need to perform derived-to-base casts and/or field accesses, to
293    // get from the temporary object we created (and, potentially, for which we
294    // extended the lifetime) to the subobject we're binding the reference to.
295    if (!Adjustments.empty()) {
296      llvm::Value *Object = RV.getAggregateAddr();
297      for (unsigned I = Adjustments.size(); I != 0; --I) {
298        SubobjectAdjustment &Adjustment = Adjustments[I-1];
299        switch (Adjustment.Kind) {
300        case SubobjectAdjustment::DerivedToBaseAdjustment:
301          Object =
302              CGF.GetAddressOfBaseClass(Object,
303                                        Adjustment.DerivedToBase.DerivedClass,
304                              Adjustment.DerivedToBase.BasePath->path_begin(),
305                              Adjustment.DerivedToBase.BasePath->path_end(),
306                                        /*NullCheckValue=*/false);
307          break;
308
309        case SubobjectAdjustment::FieldAdjustment: {
310          LValue LV =
311            CGF.EmitLValueForField(Object, Adjustment.Field, 0);
312          if (LV.isSimple()) {
313            Object = LV.getAddress();
314            break;
315          }
316
317          // For non-simple lvalues, we actually have to create a copy of
318          // the object we're binding to.
319          QualType T = Adjustment.Field->getType().getNonReferenceType()
320                                                  .getUnqualifiedType();
321          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
322          LValue TempLV = CGF.MakeAddrLValue(Object,
323                                             Adjustment.Field->getType());
324          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV, T), TempLV, T);
325          break;
326        }
327
328        }
329      }
330
331      const llvm::Type *ResultPtrTy = CGF.ConvertType(ResultTy)->getPointerTo();
332      return CGF.Builder.CreateBitCast(Object, ResultPtrTy, "temp");
333    }
334  }
335
336  if (RV.isAggregate())
337    return RV.getAggregateAddr();
338
339  // Create a temporary variable that we can bind the reference to.
340  ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
341                                                InitializedDecl);
342
343
344  unsigned Alignment =
345    CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
346  if (RV.isScalar())
347    CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
348                          /*Volatile=*/false, Alignment, E->getType());
349  else
350    CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
351                           /*Volatile=*/false);
352  return ReferenceTemporary;
353}
354
355RValue
356CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E,
357                                            const NamedDecl *InitializedDecl) {
358  llvm::Value *ReferenceTemporary = 0;
359  const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
360  llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
361                                                   ReferenceTemporaryDtor,
362                                                   InitializedDecl);
363  if (!ReferenceTemporaryDtor)
364    return RValue::get(Value);
365
366  // Make sure to call the destructor for the reference temporary.
367  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
368    if (VD->hasGlobalStorage()) {
369      llvm::Constant *DtorFn =
370        CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
371      EmitCXXGlobalDtorRegistration(DtorFn,
372                                    cast<llvm::Constant>(ReferenceTemporary));
373
374      return RValue::get(Value);
375    }
376  }
377
378  PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
379
380  return RValue::get(Value);
381}
382
383
384/// getAccessedFieldNo - Given an encoded value and a result number, return the
385/// input field number being accessed.
386unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
387                                             const llvm::Constant *Elts) {
388  if (isa<llvm::ConstantAggregateZero>(Elts))
389    return 0;
390
391  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
392}
393
394void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
395  if (!CatchUndefined)
396    return;
397
398  // This needs to be to the standard address space.
399  Address = Builder.CreateBitCast(Address, Int8PtrTy);
400
401  const llvm::Type *IntPtrT = IntPtrTy;
402  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
403
404  // In time, people may want to control this and use a 1 here.
405  llvm::Value *Arg = Builder.getFalse();
406  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
407  llvm::BasicBlock *Cont = createBasicBlock();
408  llvm::BasicBlock *Check = createBasicBlock();
409  llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
410  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
411
412  EmitBlock(Check);
413  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
414                                        llvm::ConstantInt::get(IntPtrTy, Size)),
415                       Cont, getTrapBB());
416  EmitBlock(Cont);
417}
418
419
420CodeGenFunction::ComplexPairTy CodeGenFunction::
421EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
422                         bool isInc, bool isPre) {
423  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
424                                            LV.isVolatileQualified());
425
426  llvm::Value *NextVal;
427  if (isa<llvm::IntegerType>(InVal.first->getType())) {
428    uint64_t AmountVal = isInc ? 1 : -1;
429    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
430
431    // Add the inc/dec to the real part.
432    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
433  } else {
434    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
435    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
436    if (!isInc)
437      FVal.changeSign();
438    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
439
440    // Add the inc/dec to the real part.
441    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
442  }
443
444  ComplexPairTy IncVal(NextVal, InVal.second);
445
446  // Store the updated result through the lvalue.
447  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
448
449  // If this is a postinc, return the value read from memory, otherwise use the
450  // updated value.
451  return isPre ? IncVal : InVal;
452}
453
454
455//===----------------------------------------------------------------------===//
456//                         LValue Expression Emission
457//===----------------------------------------------------------------------===//
458
459RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
460  if (Ty->isVoidType())
461    return RValue::get(0);
462
463  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
464    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
465    llvm::Value *U = llvm::UndefValue::get(EltTy);
466    return RValue::getComplex(std::make_pair(U, U));
467  }
468
469  // If this is a use of an undefined aggregate type, the aggregate must have an
470  // identifiable address.  Just because the contents of the value are undefined
471  // doesn't mean that the address can't be taken and compared.
472  if (hasAggregateLLVMType(Ty)) {
473    llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
474    return RValue::getAggregate(DestPtr);
475  }
476
477  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
478}
479
480RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
481                                              const char *Name) {
482  ErrorUnsupported(E, Name);
483  return GetUndefRValue(E->getType());
484}
485
486LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
487                                              const char *Name) {
488  ErrorUnsupported(E, Name);
489  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
490  return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType());
491}
492
493LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
494  LValue LV = EmitLValue(E);
495  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
496    EmitCheck(LV.getAddress(),
497              getContext().getTypeSizeInChars(E->getType()).getQuantity());
498  return LV;
499}
500
501/// EmitLValue - Emit code to compute a designator that specifies the location
502/// of the expression.
503///
504/// This can return one of two things: a simple address or a bitfield reference.
505/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
506/// an LLVM pointer type.
507///
508/// If this returns a bitfield reference, nothing about the pointee type of the
509/// LLVM value is known: For example, it may not be a pointer to an integer.
510///
511/// If this returns a normal address, and if the lvalue's C type is fixed size,
512/// this method guarantees that the returned pointer type will point to an LLVM
513/// type of the same size of the lvalue's type.  If the lvalue has a variable
514/// length type, this is not possible.
515///
516LValue CodeGenFunction::EmitLValue(const Expr *E) {
517  switch (E->getStmtClass()) {
518  default: return EmitUnsupportedLValue(E, "l-value expression");
519
520  case Expr::ObjCSelectorExprClass:
521  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
522  case Expr::ObjCIsaExprClass:
523    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
524  case Expr::BinaryOperatorClass:
525    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
526  case Expr::CompoundAssignOperatorClass:
527    if (!E->getType()->isAnyComplexType())
528      return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
529    return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
530  case Expr::CallExprClass:
531  case Expr::CXXMemberCallExprClass:
532  case Expr::CXXOperatorCallExprClass:
533    return EmitCallExprLValue(cast<CallExpr>(E));
534  case Expr::VAArgExprClass:
535    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
536  case Expr::DeclRefExprClass:
537    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
538  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
539  case Expr::PredefinedExprClass:
540    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
541  case Expr::StringLiteralClass:
542    return EmitStringLiteralLValue(cast<StringLiteral>(E));
543  case Expr::ObjCEncodeExprClass:
544    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
545
546  case Expr::BlockDeclRefExprClass:
547    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
548
549  case Expr::CXXTemporaryObjectExprClass:
550  case Expr::CXXConstructExprClass:
551    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
552  case Expr::CXXBindTemporaryExprClass:
553    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
554  case Expr::ExprWithCleanupsClass:
555    return EmitExprWithCleanupsLValue(cast<ExprWithCleanups>(E));
556  case Expr::CXXScalarValueInitExprClass:
557    return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
558  case Expr::CXXDefaultArgExprClass:
559    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
560  case Expr::CXXTypeidExprClass:
561    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
562
563  case Expr::ObjCMessageExprClass:
564    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
565  case Expr::ObjCIvarRefExprClass:
566    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
567  case Expr::ObjCPropertyRefExprClass:
568    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
569  case Expr::StmtExprClass:
570    return EmitStmtExprLValue(cast<StmtExpr>(E));
571  case Expr::UnaryOperatorClass:
572    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
573  case Expr::ArraySubscriptExprClass:
574    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
575  case Expr::ExtVectorElementExprClass:
576    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
577  case Expr::MemberExprClass:
578    return EmitMemberExpr(cast<MemberExpr>(E));
579  case Expr::CompoundLiteralExprClass:
580    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
581  case Expr::ConditionalOperatorClass:
582    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
583  case Expr::BinaryConditionalOperatorClass:
584    return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
585  case Expr::ChooseExprClass:
586    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
587  case Expr::OpaqueValueExprClass:
588    return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
589  case Expr::ImplicitCastExprClass:
590  case Expr::CStyleCastExprClass:
591  case Expr::CXXFunctionalCastExprClass:
592  case Expr::CXXStaticCastExprClass:
593  case Expr::CXXDynamicCastExprClass:
594  case Expr::CXXReinterpretCastExprClass:
595  case Expr::CXXConstCastExprClass:
596    return EmitCastLValue(cast<CastExpr>(E));
597  }
598}
599
600llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
601                                              unsigned Alignment, QualType Ty,
602                                              llvm::MDNode *TBAAInfo) {
603  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
604  if (Volatile)
605    Load->setVolatile(true);
606  if (Alignment)
607    Load->setAlignment(Alignment);
608  if (TBAAInfo)
609    CGM.DecorateInstruction(Load, TBAAInfo);
610
611  return EmitFromMemory(Load, Ty);
612}
613
614static bool isBooleanUnderlyingType(QualType Ty) {
615  if (const EnumType *ET = dyn_cast<EnumType>(Ty))
616    return ET->getDecl()->getIntegerType()->isBooleanType();
617  return false;
618}
619
620llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
621  // Bool has a different representation in memory than in registers.
622  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
623    // This should really always be an i1, but sometimes it's already
624    // an i8, and it's awkward to track those cases down.
625    if (Value->getType()->isIntegerTy(1))
626      return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool");
627    assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8");
628  }
629
630  return Value;
631}
632
633llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
634  // Bool has a different representation in memory than in registers.
635  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
636    assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8");
637    return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
638  }
639
640  return Value;
641}
642
643void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
644                                        bool Volatile, unsigned Alignment,
645                                        QualType Ty,
646                                        llvm::MDNode *TBAAInfo) {
647  Value = EmitToMemory(Value, Ty);
648  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
649  if (Alignment)
650    Store->setAlignment(Alignment);
651  if (TBAAInfo)
652    CGM.DecorateInstruction(Store, TBAAInfo);
653}
654
655/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
656/// method emits the address of the lvalue, then loads the result as an rvalue,
657/// returning the rvalue.
658RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
659  if (LV.isObjCWeak()) {
660    // load of a __weak object.
661    llvm::Value *AddrWeakObj = LV.getAddress();
662    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
663                                                             AddrWeakObj));
664  }
665
666  if (LV.isSimple()) {
667    llvm::Value *Ptr = LV.getAddress();
668
669    // Functions are l-values that don't require loading.
670    if (ExprType->isFunctionType())
671      return RValue::get(Ptr);
672
673    // Everything needs a load.
674    return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
675                                        LV.getAlignment(), ExprType,
676                                        LV.getTBAAInfo()));
677
678  }
679
680  if (LV.isVectorElt()) {
681    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
682                                          LV.isVolatileQualified(), "tmp");
683    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
684                                                    "vecext"));
685  }
686
687  // If this is a reference to a subset of the elements of a vector, either
688  // shuffle the input or extract/insert them as appropriate.
689  if (LV.isExtVectorElt())
690    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
691
692  if (LV.isBitField())
693    return EmitLoadOfBitfieldLValue(LV, ExprType);
694
695  assert(LV.isPropertyRef() && "Unknown LValue type!");
696  return EmitLoadOfPropertyRefLValue(LV);
697}
698
699RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
700                                                 QualType ExprType) {
701  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
702
703  // Get the output type.
704  const llvm::Type *ResLTy = ConvertType(ExprType);
705  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
706
707  // Compute the result as an OR of all of the individual component accesses.
708  llvm::Value *Res = 0;
709  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
710    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
711
712    // Get the field pointer.
713    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
714
715    // Only offset by the field index if used, so that incoming values are not
716    // required to be structures.
717    if (AI.FieldIndex)
718      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
719
720    // Offset by the byte offset, if used.
721    if (AI.FieldByteOffset) {
722      Ptr = EmitCastToVoidPtr(Ptr);
723      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
724    }
725
726    // Cast to the access type.
727    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(getLLVMContext(),
728                                                     AI.AccessWidth,
729                                                    ExprType.getAddressSpace());
730    Ptr = Builder.CreateBitCast(Ptr, PTy);
731
732    // Perform the load.
733    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
734    if (AI.AccessAlignment)
735      Load->setAlignment(AI.AccessAlignment);
736
737    // Shift out unused low bits and mask out unused high bits.
738    llvm::Value *Val = Load;
739    if (AI.FieldBitStart)
740      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
741    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
742                                                            AI.TargetBitWidth),
743                            "bf.clear");
744
745    // Extend or truncate to the target size.
746    if (AI.AccessWidth < ResSizeInBits)
747      Val = Builder.CreateZExt(Val, ResLTy);
748    else if (AI.AccessWidth > ResSizeInBits)
749      Val = Builder.CreateTrunc(Val, ResLTy);
750
751    // Shift into place, and OR into the result.
752    if (AI.TargetBitOffset)
753      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
754    Res = Res ? Builder.CreateOr(Res, Val) : Val;
755  }
756
757  // If the bit-field is signed, perform the sign-extension.
758  //
759  // FIXME: This can easily be folded into the load of the high bits, which
760  // could also eliminate the mask of high bits in some situations.
761  if (Info.isSigned()) {
762    unsigned ExtraBits = ResSizeInBits - Info.getSize();
763    if (ExtraBits)
764      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
765                               ExtraBits, "bf.val.sext");
766  }
767
768  return RValue::get(Res);
769}
770
771// If this is a reference to a subset of the elements of a vector, create an
772// appropriate shufflevector.
773RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
774                                                         QualType ExprType) {
775  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
776                                        LV.isVolatileQualified(), "tmp");
777
778  const llvm::Constant *Elts = LV.getExtVectorElts();
779
780  // If the result of the expression is a non-vector type, we must be extracting
781  // a single element.  Just codegen as an extractelement.
782  const VectorType *ExprVT = ExprType->getAs<VectorType>();
783  if (!ExprVT) {
784    unsigned InIdx = getAccessedFieldNo(0, Elts);
785    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
786    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
787  }
788
789  // Always use shuffle vector to try to retain the original program structure
790  unsigned NumResultElts = ExprVT->getNumElements();
791
792  llvm::SmallVector<llvm::Constant*, 4> Mask;
793  for (unsigned i = 0; i != NumResultElts; ++i) {
794    unsigned InIdx = getAccessedFieldNo(i, Elts);
795    Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx));
796  }
797
798  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
799  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
800                                    MaskV, "tmp");
801  return RValue::get(Vec);
802}
803
804
805
806/// EmitStoreThroughLValue - Store the specified rvalue into the specified
807/// lvalue, where both are guaranteed to the have the same type, and that type
808/// is 'Ty'.
809void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
810                                             QualType Ty) {
811  if (!Dst.isSimple()) {
812    if (Dst.isVectorElt()) {
813      // Read/modify/write the vector, inserting the new element.
814      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
815                                            Dst.isVolatileQualified(), "tmp");
816      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
817                                        Dst.getVectorIdx(), "vecins");
818      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
819      return;
820    }
821
822    // If this is an update of extended vector elements, insert them as
823    // appropriate.
824    if (Dst.isExtVectorElt())
825      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
826
827    if (Dst.isBitField())
828      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
829
830    assert(Dst.isPropertyRef() && "Unknown LValue type");
831    return EmitStoreThroughPropertyRefLValue(Src, Dst);
832  }
833
834  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
835    // load of a __weak object.
836    llvm::Value *LvalueDst = Dst.getAddress();
837    llvm::Value *src = Src.getScalarVal();
838     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
839    return;
840  }
841
842  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
843    // load of a __strong object.
844    llvm::Value *LvalueDst = Dst.getAddress();
845    llvm::Value *src = Src.getScalarVal();
846    if (Dst.isObjCIvar()) {
847      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
848      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
849      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
850      llvm::Value *dst = RHS;
851      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
852      llvm::Value *LHS =
853        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
854      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
855      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
856                                              BytesBetween);
857    } else if (Dst.isGlobalObjCRef()) {
858      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
859                                                Dst.isThreadLocalRef());
860    }
861    else
862      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
863    return;
864  }
865
866  assert(Src.isScalar() && "Can't emit an agg store with this method");
867  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
868                    Dst.isVolatileQualified(), Dst.getAlignment(), Ty,
869                    Dst.getTBAAInfo());
870}
871
872void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
873                                                     QualType Ty,
874                                                     llvm::Value **Result) {
875  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
876
877  // Get the output type.
878  const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
879  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
880
881  // Get the source value, truncated to the width of the bit-field.
882  llvm::Value *SrcVal = Src.getScalarVal();
883
884  if (Ty->isBooleanType())
885    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
886
887  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
888                                                                Info.getSize()),
889                             "bf.value");
890
891  // Return the new value of the bit-field, if requested.
892  if (Result) {
893    // Cast back to the proper type for result.
894    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
895    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
896                                                   "bf.reload.val");
897
898    // Sign extend if necessary.
899    if (Info.isSigned()) {
900      unsigned ExtraBits = ResSizeInBits - Info.getSize();
901      if (ExtraBits)
902        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
903                                       ExtraBits, "bf.reload.sext");
904    }
905
906    *Result = ReloadVal;
907  }
908
909  // Iterate over the components, writing each piece to memory.
910  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
911    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
912
913    // Get the field pointer.
914    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
915    unsigned addressSpace =
916      cast<llvm::PointerType>(Ptr->getType())->getAddressSpace();
917
918    // Only offset by the field index if used, so that incoming values are not
919    // required to be structures.
920    if (AI.FieldIndex)
921      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
922
923    // Offset by the byte offset, if used.
924    if (AI.FieldByteOffset) {
925      Ptr = EmitCastToVoidPtr(Ptr);
926      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
927    }
928
929    // Cast to the access type.
930    const llvm::Type *AccessLTy =
931      llvm::Type::getIntNTy(getLLVMContext(), AI.AccessWidth);
932
933    const llvm::Type *PTy = AccessLTy->getPointerTo(addressSpace);
934    Ptr = Builder.CreateBitCast(Ptr, PTy);
935
936    // Extract the piece of the bit-field value to write in this access, limited
937    // to the values that are part of this access.
938    llvm::Value *Val = SrcVal;
939    if (AI.TargetBitOffset)
940      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
941    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
942                                                            AI.TargetBitWidth));
943
944    // Extend or truncate to the access size.
945    if (ResSizeInBits < AI.AccessWidth)
946      Val = Builder.CreateZExt(Val, AccessLTy);
947    else if (ResSizeInBits > AI.AccessWidth)
948      Val = Builder.CreateTrunc(Val, AccessLTy);
949
950    // Shift into the position in memory.
951    if (AI.FieldBitStart)
952      Val = Builder.CreateShl(Val, AI.FieldBitStart);
953
954    // If necessary, load and OR in bits that are outside of the bit-field.
955    if (AI.TargetBitWidth != AI.AccessWidth) {
956      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
957      if (AI.AccessAlignment)
958        Load->setAlignment(AI.AccessAlignment);
959
960      // Compute the mask for zeroing the bits that are part of the bit-field.
961      llvm::APInt InvMask =
962        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
963                                 AI.FieldBitStart + AI.TargetBitWidth);
964
965      // Apply the mask and OR in to the value to write.
966      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
967    }
968
969    // Write the value.
970    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
971                                                 Dst.isVolatileQualified());
972    if (AI.AccessAlignment)
973      Store->setAlignment(AI.AccessAlignment);
974  }
975}
976
977void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
978                                                               LValue Dst,
979                                                               QualType Ty) {
980  // This access turns into a read/modify/write of the vector.  Load the input
981  // value now.
982  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
983                                        Dst.isVolatileQualified(), "tmp");
984  const llvm::Constant *Elts = Dst.getExtVectorElts();
985
986  llvm::Value *SrcVal = Src.getScalarVal();
987
988  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
989    unsigned NumSrcElts = VTy->getNumElements();
990    unsigned NumDstElts =
991       cast<llvm::VectorType>(Vec->getType())->getNumElements();
992    if (NumDstElts == NumSrcElts) {
993      // Use shuffle vector is the src and destination are the same number of
994      // elements and restore the vector mask since it is on the side it will be
995      // stored.
996      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
997      for (unsigned i = 0; i != NumSrcElts; ++i) {
998        unsigned InIdx = getAccessedFieldNo(i, Elts);
999        Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
1000      }
1001
1002      llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1003      Vec = Builder.CreateShuffleVector(SrcVal,
1004                                        llvm::UndefValue::get(Vec->getType()),
1005                                        MaskV, "tmp");
1006    } else if (NumDstElts > NumSrcElts) {
1007      // Extended the source vector to the same length and then shuffle it
1008      // into the destination.
1009      // FIXME: since we're shuffling with undef, can we just use the indices
1010      //        into that?  This could be simpler.
1011      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1012      unsigned i;
1013      for (i = 0; i != NumSrcElts; ++i)
1014        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1015      for (; i != NumDstElts; ++i)
1016        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1017      llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1018      llvm::Value *ExtSrcVal =
1019        Builder.CreateShuffleVector(SrcVal,
1020                                    llvm::UndefValue::get(SrcVal->getType()),
1021                                    ExtMaskV, "tmp");
1022      // build identity
1023      llvm::SmallVector<llvm::Constant*, 4> Mask;
1024      for (unsigned i = 0; i != NumDstElts; ++i)
1025        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1026
1027      // modify when what gets shuffled in
1028      for (unsigned i = 0; i != NumSrcElts; ++i) {
1029        unsigned Idx = getAccessedFieldNo(i, Elts);
1030        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
1031      }
1032      llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1033      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
1034    } else {
1035      // We should never shorten the vector
1036      assert(0 && "unexpected shorten vector length");
1037    }
1038  } else {
1039    // If the Src is a scalar (not a vector) it must be updating one element.
1040    unsigned InIdx = getAccessedFieldNo(0, Elts);
1041    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
1042    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
1043  }
1044
1045  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
1046}
1047
1048// setObjCGCLValueClass - sets class of he lvalue for the purpose of
1049// generating write-barries API. It is currently a global, ivar,
1050// or neither.
1051static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1052                                 LValue &LV) {
1053  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
1054    return;
1055
1056  if (isa<ObjCIvarRefExpr>(E)) {
1057    LV.setObjCIvar(true);
1058    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
1059    LV.setBaseIvarExp(Exp->getBase());
1060    LV.setObjCArray(E->getType()->isArrayType());
1061    return;
1062  }
1063
1064  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
1065    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1066      if (VD->hasGlobalStorage()) {
1067        LV.setGlobalObjCRef(true);
1068        LV.setThreadLocalRef(VD->isThreadSpecified());
1069      }
1070    }
1071    LV.setObjCArray(E->getType()->isArrayType());
1072    return;
1073  }
1074
1075  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
1076    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1077    return;
1078  }
1079
1080  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
1081    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1082    if (LV.isObjCIvar()) {
1083      // If cast is to a structure pointer, follow gcc's behavior and make it
1084      // a non-ivar write-barrier.
1085      QualType ExpTy = E->getType();
1086      if (ExpTy->isPointerType())
1087        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1088      if (ExpTy->isRecordType())
1089        LV.setObjCIvar(false);
1090    }
1091    return;
1092  }
1093  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1094    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1095    return;
1096  }
1097
1098  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1099    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1100    return;
1101  }
1102
1103  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1104    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1105    if (LV.isObjCIvar() && !LV.isObjCArray())
1106      // Using array syntax to assigning to what an ivar points to is not
1107      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1108      LV.setObjCIvar(false);
1109    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1110      // Using array syntax to assigning to what global points to is not
1111      // same as assigning to the global itself. {id *G;} G[i] = 0;
1112      LV.setGlobalObjCRef(false);
1113    return;
1114  }
1115
1116  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1117    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1118    // We don't know if member is an 'ivar', but this flag is looked at
1119    // only in the context of LV.isObjCIvar().
1120    LV.setObjCArray(E->getType()->isArrayType());
1121    return;
1122  }
1123}
1124
1125static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1126                                      const Expr *E, const VarDecl *VD) {
1127  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1128         "Var decl must have external storage or be a file var decl!");
1129
1130  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1131  if (VD->getType()->isReferenceType())
1132    V = CGF.Builder.CreateLoad(V, "tmp");
1133  unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity();
1134  LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment);
1135  setObjCGCLValueClass(CGF.getContext(), E, LV);
1136  return LV;
1137}
1138
1139static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1140                                      const Expr *E, const FunctionDecl *FD) {
1141  llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
1142  if (!FD->hasPrototype()) {
1143    if (const FunctionProtoType *Proto =
1144            FD->getType()->getAs<FunctionProtoType>()) {
1145      // Ugly case: for a K&R-style definition, the type of the definition
1146      // isn't the same as the type of a use.  Correct for this with a
1147      // bitcast.
1148      QualType NoProtoType =
1149          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1150      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1151      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1152    }
1153  }
1154  unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity();
1155  return CGF.MakeAddrLValue(V, E->getType(), Alignment);
1156}
1157
1158LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1159  const NamedDecl *ND = E->getDecl();
1160  unsigned Alignment = getContext().getDeclAlign(ND).getQuantity();
1161
1162  if (ND->hasAttr<WeakRefAttr>()) {
1163    const ValueDecl *VD = cast<ValueDecl>(ND);
1164    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1165    return MakeAddrLValue(Aliasee, E->getType(), Alignment);
1166  }
1167
1168  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1169
1170    // Check if this is a global variable.
1171    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1172      return EmitGlobalVarDeclLValue(*this, E, VD);
1173
1174    bool NonGCable = VD->hasLocalStorage() &&
1175                     !VD->getType()->isReferenceType() &&
1176                     !VD->hasAttr<BlocksAttr>();
1177
1178    llvm::Value *V = LocalDeclMap[VD];
1179    if (!V && VD->isStaticLocal())
1180      V = CGM.getStaticLocalDeclAddress(VD);
1181    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1182
1183    if (VD->hasAttr<BlocksAttr>())
1184      V = BuildBlockByrefAddress(V, VD);
1185
1186    if (VD->getType()->isReferenceType())
1187      V = Builder.CreateLoad(V, "tmp");
1188
1189    LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
1190    if (NonGCable) {
1191      LV.getQuals().removeObjCGCAttr();
1192      LV.setNonGC(true);
1193    }
1194    setObjCGCLValueClass(getContext(), E, LV);
1195    return LV;
1196  }
1197
1198  if (const FunctionDecl *fn = dyn_cast<FunctionDecl>(ND))
1199    return EmitFunctionDeclLValue(*this, E, fn);
1200
1201  assert(false && "Unhandled DeclRefExpr");
1202
1203  // an invalid LValue, but the assert will
1204  // ensure that this point is never reached.
1205  return LValue();
1206}
1207
1208LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1209  unsigned Alignment =
1210    getContext().getDeclAlign(E->getDecl()).getQuantity();
1211  return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
1212}
1213
1214LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1215  // __extension__ doesn't affect lvalue-ness.
1216  if (E->getOpcode() == UO_Extension)
1217    return EmitLValue(E->getSubExpr());
1218
1219  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1220  switch (E->getOpcode()) {
1221  default: assert(0 && "Unknown unary operator lvalue!");
1222  case UO_Deref: {
1223    QualType T = E->getSubExpr()->getType()->getPointeeType();
1224    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1225
1226    LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
1227    LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
1228
1229    // We should not generate __weak write barrier on indirect reference
1230    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1231    // But, we continue to generate __strong write barrier on indirect write
1232    // into a pointer to object.
1233    if (getContext().getLangOptions().ObjC1 &&
1234        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1235        LV.isObjCWeak())
1236      LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1237    return LV;
1238  }
1239  case UO_Real:
1240  case UO_Imag: {
1241    LValue LV = EmitLValue(E->getSubExpr());
1242    assert(LV.isSimple() && "real/imag on non-ordinary l-value");
1243    llvm::Value *Addr = LV.getAddress();
1244
1245    // real and imag are valid on scalars.  This is a faster way of
1246    // testing that.
1247    if (!cast<llvm::PointerType>(Addr->getType())
1248           ->getElementType()->isStructTy()) {
1249      assert(E->getSubExpr()->getType()->isArithmeticType());
1250      return LV;
1251    }
1252
1253    assert(E->getSubExpr()->getType()->isAnyComplexType());
1254
1255    unsigned Idx = E->getOpcode() == UO_Imag;
1256    return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
1257                                                  Idx, "idx"),
1258                          ExprTy);
1259  }
1260  case UO_PreInc:
1261  case UO_PreDec: {
1262    LValue LV = EmitLValue(E->getSubExpr());
1263    bool isInc = E->getOpcode() == UO_PreInc;
1264
1265    if (E->getType()->isAnyComplexType())
1266      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1267    else
1268      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1269    return LV;
1270  }
1271  }
1272}
1273
1274LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1275  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
1276                        E->getType());
1277}
1278
1279LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1280  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1281                        E->getType());
1282}
1283
1284
1285LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1286  switch (E->getIdentType()) {
1287  default:
1288    return EmitUnsupportedLValue(E, "predefined expression");
1289
1290  case PredefinedExpr::Func:
1291  case PredefinedExpr::Function:
1292  case PredefinedExpr::PrettyFunction: {
1293    unsigned Type = E->getIdentType();
1294    std::string GlobalVarName;
1295
1296    switch (Type) {
1297    default: assert(0 && "Invalid type");
1298    case PredefinedExpr::Func:
1299      GlobalVarName = "__func__.";
1300      break;
1301    case PredefinedExpr::Function:
1302      GlobalVarName = "__FUNCTION__.";
1303      break;
1304    case PredefinedExpr::PrettyFunction:
1305      GlobalVarName = "__PRETTY_FUNCTION__.";
1306      break;
1307    }
1308
1309    llvm::StringRef FnName = CurFn->getName();
1310    if (FnName.startswith("\01"))
1311      FnName = FnName.substr(1);
1312    GlobalVarName += FnName;
1313
1314    const Decl *CurDecl = CurCodeDecl;
1315    if (CurDecl == 0)
1316      CurDecl = getContext().getTranslationUnitDecl();
1317
1318    std::string FunctionName =
1319        (isa<BlockDecl>(CurDecl)
1320         ? FnName.str()
1321         : PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl));
1322
1323    llvm::Constant *C =
1324      CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1325    return MakeAddrLValue(C, E->getType());
1326  }
1327  }
1328}
1329
1330llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1331  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1332
1333  // If we are not optimzing, don't collapse all calls to trap in the function
1334  // to the same call, that way, in the debugger they can see which operation
1335  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1336  // to just one per function to save on codesize.
1337  if (GCO.OptimizationLevel && TrapBB)
1338    return TrapBB;
1339
1340  llvm::BasicBlock *Cont = 0;
1341  if (HaveInsertPoint()) {
1342    Cont = createBasicBlock("cont");
1343    EmitBranch(Cont);
1344  }
1345  TrapBB = createBasicBlock("trap");
1346  EmitBlock(TrapBB);
1347
1348  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1349  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1350  TrapCall->setDoesNotReturn();
1351  TrapCall->setDoesNotThrow();
1352  Builder.CreateUnreachable();
1353
1354  if (Cont)
1355    EmitBlock(Cont);
1356  return TrapBB;
1357}
1358
1359/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1360/// array to pointer, return the array subexpression.
1361static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1362  // If this isn't just an array->pointer decay, bail out.
1363  const CastExpr *CE = dyn_cast<CastExpr>(E);
1364  if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay)
1365    return 0;
1366
1367  // If this is a decay from variable width array, bail out.
1368  const Expr *SubExpr = CE->getSubExpr();
1369  if (SubExpr->getType()->isVariableArrayType())
1370    return 0;
1371
1372  return SubExpr;
1373}
1374
1375LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1376  // The index must always be an integer, which is not an aggregate.  Emit it.
1377  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1378  QualType IdxTy  = E->getIdx()->getType();
1379  bool IdxSigned = IdxTy->isSignedIntegerType();
1380
1381  // If the base is a vector type, then we are forming a vector element lvalue
1382  // with this subscript.
1383  if (E->getBase()->getType()->isVectorType()) {
1384    // Emit the vector as an lvalue to get its address.
1385    LValue LHS = EmitLValue(E->getBase());
1386    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1387    Idx = Builder.CreateIntCast(Idx, Int32Ty, IdxSigned, "vidx");
1388    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1389                                 E->getBase()->getType().getCVRQualifiers());
1390  }
1391
1392  // Extend or truncate the index type to 32 or 64-bits.
1393  if (Idx->getType() != IntPtrTy)
1394    Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
1395
1396  // FIXME: As llvm implements the object size checking, this can come out.
1397  if (CatchUndefined) {
1398    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1399      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1400        if (ICE->getCastKind() == CK_ArrayToPointerDecay) {
1401          if (const ConstantArrayType *CAT
1402              = getContext().getAsConstantArrayType(DRE->getType())) {
1403            llvm::APInt Size = CAT->getSize();
1404            llvm::BasicBlock *Cont = createBasicBlock("cont");
1405            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1406                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1407                                 Cont, getTrapBB());
1408            EmitBlock(Cont);
1409          }
1410        }
1411      }
1412    }
1413  }
1414
1415  // We know that the pointer points to a type of the correct size, unless the
1416  // size is a VLA or Objective-C interface.
1417  llvm::Value *Address = 0;
1418  if (const VariableArrayType *VAT =
1419        getContext().getAsVariableArrayType(E->getType())) {
1420    llvm::Value *VLASize = GetVLASize(VAT);
1421
1422    Idx = Builder.CreateMul(Idx, VLASize);
1423
1424    // The base must be a pointer, which is not an aggregate.  Emit it.
1425    llvm::Value *Base = EmitScalarExpr(E->getBase());
1426
1427    Address = EmitCastToVoidPtr(Base);
1428    if (getContext().getLangOptions().isSignedOverflowDefined())
1429      Address = Builder.CreateGEP(Address, Idx, "arrayidx");
1430    else
1431      Address = Builder.CreateInBoundsGEP(Address, Idx, "arrayidx");
1432    Address = Builder.CreateBitCast(Address, Base->getType());
1433  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1434    // Indexing over an interface, as in "NSString *P; P[4];"
1435    llvm::Value *InterfaceSize =
1436      llvm::ConstantInt::get(Idx->getType(),
1437          getContext().getTypeSizeInChars(OIT).getQuantity());
1438
1439    Idx = Builder.CreateMul(Idx, InterfaceSize);
1440
1441    // The base must be a pointer, which is not an aggregate.  Emit it.
1442    llvm::Value *Base = EmitScalarExpr(E->getBase());
1443    Address = EmitCastToVoidPtr(Base);
1444    Address = Builder.CreateGEP(Address, Idx, "arrayidx");
1445    Address = Builder.CreateBitCast(Address, Base->getType());
1446  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1447    // If this is A[i] where A is an array, the frontend will have decayed the
1448    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1449    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1450    // "gep x, i" here.  Emit one "gep A, 0, i".
1451    assert(Array->getType()->isArrayType() &&
1452           "Array to pointer decay must have array source type!");
1453    llvm::Value *ArrayPtr = EmitLValue(Array).getAddress();
1454    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1455    llvm::Value *Args[] = { Zero, Idx };
1456
1457    if (getContext().getLangOptions().isSignedOverflowDefined())
1458      Address = Builder.CreateGEP(ArrayPtr, Args, Args+2, "arrayidx");
1459    else
1460      Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1461  } else {
1462    // The base must be a pointer, which is not an aggregate.  Emit it.
1463    llvm::Value *Base = EmitScalarExpr(E->getBase());
1464    if (getContext().getLangOptions().isSignedOverflowDefined())
1465      Address = Builder.CreateGEP(Base, Idx, "arrayidx");
1466    else
1467      Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1468  }
1469
1470  QualType T = E->getBase()->getType()->getPointeeType();
1471  assert(!T.isNull() &&
1472         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1473
1474  LValue LV = MakeAddrLValue(Address, T);
1475  LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
1476
1477  if (getContext().getLangOptions().ObjC1 &&
1478      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1479    LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1480    setObjCGCLValueClass(getContext(), E, LV);
1481  }
1482  return LV;
1483}
1484
1485static
1486llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1487                                       llvm::SmallVector<unsigned, 4> &Elts) {
1488  llvm::SmallVector<llvm::Constant*, 4> CElts;
1489
1490  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1491  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1492    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1493
1494  return llvm::ConstantVector::get(CElts);
1495}
1496
1497LValue CodeGenFunction::
1498EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1499  // Emit the base vector as an l-value.
1500  LValue Base;
1501
1502  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1503  if (E->isArrow()) {
1504    // If it is a pointer to a vector, emit the address and form an lvalue with
1505    // it.
1506    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1507    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1508    Base = MakeAddrLValue(Ptr, PT->getPointeeType());
1509    Base.getQuals().removeObjCGCAttr();
1510  } else if (E->getBase()->isGLValue()) {
1511    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1512    // emit the base as an lvalue.
1513    assert(E->getBase()->getType()->isVectorType());
1514    Base = EmitLValue(E->getBase());
1515  } else {
1516    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1517    assert(E->getBase()->getType()->getAs<VectorType>() &&
1518           "Result must be a vector");
1519    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1520
1521    // Store the vector to memory (because LValue wants an address).
1522    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1523    Builder.CreateStore(Vec, VecMem);
1524    Base = MakeAddrLValue(VecMem, E->getBase()->getType());
1525  }
1526
1527  // Encode the element access list into a vector of unsigned indices.
1528  llvm::SmallVector<unsigned, 4> Indices;
1529  E->getEncodedElementAccess(Indices);
1530
1531  if (Base.isSimple()) {
1532    llvm::Constant *CV = GenerateConstantVector(getLLVMContext(), Indices);
1533    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1534                                    Base.getVRQualifiers());
1535  }
1536  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1537
1538  llvm::Constant *BaseElts = Base.getExtVectorElts();
1539  llvm::SmallVector<llvm::Constant *, 4> CElts;
1540
1541  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1542    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1543      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1544    else
1545      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1546  }
1547  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
1548  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1549                                  Base.getVRQualifiers());
1550}
1551
1552LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1553  bool isNonGC = false;
1554  Expr *BaseExpr = E->getBase();
1555  llvm::Value *BaseValue = NULL;
1556  Qualifiers BaseQuals;
1557
1558  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1559  if (E->isArrow()) {
1560    BaseValue = EmitScalarExpr(BaseExpr);
1561    const PointerType *PTy =
1562      BaseExpr->getType()->getAs<PointerType>();
1563    BaseQuals = PTy->getPointeeType().getQualifiers();
1564  } else {
1565    LValue BaseLV = EmitLValue(BaseExpr);
1566    if (BaseLV.isNonGC())
1567      isNonGC = true;
1568    // FIXME: this isn't right for bitfields.
1569    BaseValue = BaseLV.getAddress();
1570    QualType BaseTy = BaseExpr->getType();
1571    BaseQuals = BaseTy.getQualifiers();
1572  }
1573
1574  NamedDecl *ND = E->getMemberDecl();
1575  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1576    LValue LV = EmitLValueForField(BaseValue, Field,
1577                                   BaseQuals.getCVRQualifiers());
1578    LV.setNonGC(isNonGC);
1579    setObjCGCLValueClass(getContext(), E, LV);
1580    return LV;
1581  }
1582
1583  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1584    return EmitGlobalVarDeclLValue(*this, E, VD);
1585
1586  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1587    return EmitFunctionDeclLValue(*this, E, FD);
1588
1589  assert(false && "Unhandled member declaration!");
1590  return LValue();
1591}
1592
1593LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue,
1594                                              const FieldDecl *Field,
1595                                              unsigned CVRQualifiers) {
1596  const CGRecordLayout &RL =
1597    CGM.getTypes().getCGRecordLayout(Field->getParent());
1598  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1599  return LValue::MakeBitfield(BaseValue, Info,
1600                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1601}
1602
1603/// EmitLValueForAnonRecordField - Given that the field is a member of
1604/// an anonymous struct or union buried inside a record, and given
1605/// that the base value is a pointer to the enclosing record, derive
1606/// an lvalue for the ultimate field.
1607LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1608                                             const IndirectFieldDecl *Field,
1609                                                     unsigned CVRQualifiers) {
1610  IndirectFieldDecl::chain_iterator I = Field->chain_begin(),
1611    IEnd = Field->chain_end();
1612  while (true) {
1613    LValue LV = EmitLValueForField(BaseValue, cast<FieldDecl>(*I), CVRQualifiers);
1614    if (++I == IEnd) return LV;
1615
1616    assert(LV.isSimple());
1617    BaseValue = LV.getAddress();
1618    CVRQualifiers |= LV.getVRQualifiers();
1619  }
1620}
1621
1622LValue CodeGenFunction::EmitLValueForField(llvm::Value *baseAddr,
1623                                           const FieldDecl *field,
1624                                           unsigned cvr) {
1625  if (field->isBitField())
1626    return EmitLValueForBitfield(baseAddr, field, cvr);
1627
1628  const RecordDecl *rec = field->getParent();
1629  QualType type = field->getType();
1630
1631  bool mayAlias = rec->hasAttr<MayAliasAttr>();
1632
1633  llvm::Value *addr;
1634  if (rec->isUnion()) {
1635    // For unions, we just cast to the appropriate type.
1636    assert(!type->isReferenceType() && "union has reference member");
1637
1638    const llvm::Type *llvmType = CGM.getTypes().ConvertTypeForMem(type);
1639    unsigned AS =
1640      cast<llvm::PointerType>(baseAddr->getType())->getAddressSpace();
1641    addr = Builder.CreateBitCast(baseAddr, llvmType->getPointerTo(AS),
1642                                 field->getName());
1643  } else {
1644    // For structs, we GEP to the field that the record layout suggests.
1645    unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
1646    addr = Builder.CreateStructGEP(baseAddr, idx, field->getName());
1647
1648    // If this is a reference field, load the reference right now.
1649    if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
1650      llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
1651      if (cvr & Qualifiers::Volatile) load->setVolatile(true);
1652
1653      if (CGM.shouldUseTBAA()) {
1654        llvm::MDNode *tbaa;
1655        if (mayAlias)
1656          tbaa = CGM.getTBAAInfo(getContext().CharTy);
1657        else
1658          tbaa = CGM.getTBAAInfo(type);
1659        CGM.DecorateInstruction(load, tbaa);
1660      }
1661
1662      addr = load;
1663      mayAlias = false;
1664      type = refType->getPointeeType();
1665      cvr = 0; // qualifiers don't recursively apply to referencee
1666    }
1667  }
1668
1669  unsigned alignment = getContext().getDeclAlign(field).getQuantity();
1670  LValue LV = MakeAddrLValue(addr, type, alignment);
1671  LV.getQuals().addCVRQualifiers(cvr);
1672
1673  // __weak attribute on a field is ignored.
1674  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
1675    LV.getQuals().removeObjCGCAttr();
1676
1677  // Fields of may_alias structs act like 'char' for TBAA purposes.
1678  // FIXME: this should get propagated down through anonymous structs
1679  // and unions.
1680  if (mayAlias && LV.getTBAAInfo())
1681    LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
1682
1683  return LV;
1684}
1685
1686LValue
1687CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue,
1688                                                  const FieldDecl *Field,
1689                                                  unsigned CVRQualifiers) {
1690  QualType FieldType = Field->getType();
1691
1692  if (!FieldType->isReferenceType())
1693    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1694
1695  const CGRecordLayout &RL =
1696    CGM.getTypes().getCGRecordLayout(Field->getParent());
1697  unsigned idx = RL.getLLVMFieldNo(Field);
1698  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1699
1700  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1701
1702  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1703  return MakeAddrLValue(V, FieldType, Alignment);
1704}
1705
1706LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
1707  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1708  const Expr *InitExpr = E->getInitializer();
1709  LValue Result = MakeAddrLValue(DeclPtr, E->getType());
1710
1711  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false, /*Init*/ true);
1712
1713  return Result;
1714}
1715
1716LValue CodeGenFunction::
1717EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
1718  if (!expr->isGLValue()) {
1719    // ?: here should be an aggregate.
1720    assert((hasAggregateLLVMType(expr->getType()) &&
1721            !expr->getType()->isAnyComplexType()) &&
1722           "Unexpected conditional operator!");
1723    return EmitAggExprToLValue(expr);
1724  }
1725
1726  const Expr *condExpr = expr->getCond();
1727  bool CondExprBool;
1728  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
1729    const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
1730    if (!CondExprBool) std::swap(live, dead);
1731
1732    if (!ContainsLabel(dead))
1733      return EmitLValue(live);
1734  }
1735
1736  OpaqueValueMapping binding(*this, expr);
1737
1738  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
1739  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
1740  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
1741
1742  ConditionalEvaluation eval(*this);
1743  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock);
1744
1745  // Any temporaries created here are conditional.
1746  EmitBlock(lhsBlock);
1747  eval.begin(*this);
1748  LValue lhs = EmitLValue(expr->getTrueExpr());
1749  eval.end(*this);
1750
1751  if (!lhs.isSimple())
1752    return EmitUnsupportedLValue(expr, "conditional operator");
1753
1754  lhsBlock = Builder.GetInsertBlock();
1755  Builder.CreateBr(contBlock);
1756
1757  // Any temporaries created here are conditional.
1758  EmitBlock(rhsBlock);
1759  eval.begin(*this);
1760  LValue rhs = EmitLValue(expr->getFalseExpr());
1761  eval.end(*this);
1762  if (!rhs.isSimple())
1763    return EmitUnsupportedLValue(expr, "conditional operator");
1764  rhsBlock = Builder.GetInsertBlock();
1765
1766  EmitBlock(contBlock);
1767
1768  llvm::PHINode *phi = Builder.CreatePHI(lhs.getAddress()->getType(),
1769                                         "cond-lvalue");
1770  phi->reserveOperandSpace(2);
1771  phi->addIncoming(lhs.getAddress(), lhsBlock);
1772  phi->addIncoming(rhs.getAddress(), rhsBlock);
1773  return MakeAddrLValue(phi, expr->getType());
1774}
1775
1776/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1777/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1778/// otherwise if a cast is needed by the code generator in an lvalue context,
1779/// then it must mean that we need the address of an aggregate in order to
1780/// access one of its fields.  This can happen for all the reasons that casts
1781/// are permitted with aggregate result, including noop aggregate casts, and
1782/// cast from scalar to union.
1783LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1784  switch (E->getCastKind()) {
1785  case CK_ToVoid:
1786    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1787
1788  case CK_Dependent:
1789    llvm_unreachable("dependent cast kind in IR gen!");
1790
1791  case CK_GetObjCProperty: {
1792    LValue LV = EmitLValue(E->getSubExpr());
1793    assert(LV.isPropertyRef());
1794    RValue RV = EmitLoadOfPropertyRefLValue(LV);
1795
1796    // Property is an aggregate r-value.
1797    if (RV.isAggregate()) {
1798      return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
1799    }
1800
1801    // Implicit property returns an l-value.
1802    assert(RV.isScalar());
1803    return MakeAddrLValue(RV.getScalarVal(), E->getSubExpr()->getType());
1804  }
1805
1806  case CK_NoOp:
1807  case CK_LValueToRValue:
1808    if (!E->getSubExpr()->Classify(getContext()).isPRValue()
1809        || E->getType()->isRecordType())
1810      return EmitLValue(E->getSubExpr());
1811    // Fall through to synthesize a temporary.
1812
1813  case CK_BitCast:
1814  case CK_ArrayToPointerDecay:
1815  case CK_FunctionToPointerDecay:
1816  case CK_NullToMemberPointer:
1817  case CK_NullToPointer:
1818  case CK_IntegralToPointer:
1819  case CK_PointerToIntegral:
1820  case CK_PointerToBoolean:
1821  case CK_VectorSplat:
1822  case CK_IntegralCast:
1823  case CK_IntegralToBoolean:
1824  case CK_IntegralToFloating:
1825  case CK_FloatingToIntegral:
1826  case CK_FloatingToBoolean:
1827  case CK_FloatingCast:
1828  case CK_FloatingRealToComplex:
1829  case CK_FloatingComplexToReal:
1830  case CK_FloatingComplexToBoolean:
1831  case CK_FloatingComplexCast:
1832  case CK_FloatingComplexToIntegralComplex:
1833  case CK_IntegralRealToComplex:
1834  case CK_IntegralComplexToReal:
1835  case CK_IntegralComplexToBoolean:
1836  case CK_IntegralComplexCast:
1837  case CK_IntegralComplexToFloatingComplex:
1838  case CK_DerivedToBaseMemberPointer:
1839  case CK_BaseToDerivedMemberPointer:
1840  case CK_MemberPointerToBoolean:
1841  case CK_AnyPointerToBlockPointerCast: {
1842    // These casts only produce lvalues when we're binding a reference to a
1843    // temporary realized from a (converted) pure rvalue. Emit the expression
1844    // as a value, copy it into a temporary, and return an lvalue referring to
1845    // that temporary.
1846    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
1847    EmitAnyExprToMem(E, V, false, false);
1848    return MakeAddrLValue(V, E->getType());
1849  }
1850
1851  case CK_Dynamic: {
1852    LValue LV = EmitLValue(E->getSubExpr());
1853    llvm::Value *V = LV.getAddress();
1854    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1855    return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
1856  }
1857
1858  case CK_ConstructorConversion:
1859  case CK_UserDefinedConversion:
1860  case CK_AnyPointerToObjCPointerCast:
1861    return EmitLValue(E->getSubExpr());
1862
1863  case CK_UncheckedDerivedToBase:
1864  case CK_DerivedToBase: {
1865    const RecordType *DerivedClassTy =
1866      E->getSubExpr()->getType()->getAs<RecordType>();
1867    CXXRecordDecl *DerivedClassDecl =
1868      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1869
1870    LValue LV = EmitLValue(E->getSubExpr());
1871    llvm::Value *This = LV.getAddress();
1872
1873    // Perform the derived-to-base conversion
1874    llvm::Value *Base =
1875      GetAddressOfBaseClass(This, DerivedClassDecl,
1876                            E->path_begin(), E->path_end(),
1877                            /*NullCheckValue=*/false);
1878
1879    return MakeAddrLValue(Base, E->getType());
1880  }
1881  case CK_ToUnion:
1882    return EmitAggExprToLValue(E);
1883  case CK_BaseToDerived: {
1884    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1885    CXXRecordDecl *DerivedClassDecl =
1886      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1887
1888    LValue LV = EmitLValue(E->getSubExpr());
1889
1890    // Perform the base-to-derived conversion
1891    llvm::Value *Derived =
1892      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1893                               E->path_begin(), E->path_end(),
1894                               /*NullCheckValue=*/false);
1895
1896    return MakeAddrLValue(Derived, E->getType());
1897  }
1898  case CK_LValueBitCast: {
1899    // This must be a reinterpret_cast (or c-style equivalent).
1900    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1901
1902    LValue LV = EmitLValue(E->getSubExpr());
1903    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1904                                           ConvertType(CE->getTypeAsWritten()));
1905    return MakeAddrLValue(V, E->getType());
1906  }
1907  case CK_ObjCObjectLValueCast: {
1908    LValue LV = EmitLValue(E->getSubExpr());
1909    QualType ToType = getContext().getLValueReferenceType(E->getType());
1910    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1911                                           ConvertType(ToType));
1912    return MakeAddrLValue(V, E->getType());
1913  }
1914  }
1915
1916  llvm_unreachable("Unhandled lvalue cast kind?");
1917}
1918
1919LValue CodeGenFunction::EmitNullInitializationLValue(
1920                                              const CXXScalarValueInitExpr *E) {
1921  QualType Ty = E->getType();
1922  LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
1923  EmitNullInitialization(LV.getAddress(), Ty);
1924  return LV;
1925}
1926
1927LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
1928  assert(e->isGLValue() || e->getType()->isRecordType());
1929  return getOpaqueLValueMapping(e);
1930}
1931
1932//===--------------------------------------------------------------------===//
1933//                             Expression Emission
1934//===--------------------------------------------------------------------===//
1935
1936
1937RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
1938                                     ReturnValueSlot ReturnValue) {
1939  // Builtins never have block type.
1940  if (E->getCallee()->getType()->isBlockPointerType())
1941    return EmitBlockCallExpr(E, ReturnValue);
1942
1943  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1944    return EmitCXXMemberCallExpr(CE, ReturnValue);
1945
1946  const Decl *TargetDecl = 0;
1947  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1948    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1949      TargetDecl = DRE->getDecl();
1950      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1951        if (unsigned builtinID = FD->getBuiltinID())
1952          return EmitBuiltinExpr(FD, builtinID, E);
1953    }
1954  }
1955
1956  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1957    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1958      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
1959
1960  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1961    // C++ [expr.pseudo]p1:
1962    //   The result shall only be used as the operand for the function call
1963    //   operator (), and the result of such a call has type void. The only
1964    //   effect is the evaluation of the postfix-expression before the dot or
1965    //   arrow.
1966    EmitScalarExpr(E->getCallee());
1967    return RValue::get(0);
1968  }
1969
1970  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1971  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
1972                  E->arg_begin(), E->arg_end(), TargetDecl);
1973}
1974
1975LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1976  // Comma expressions just emit their LHS then their RHS as an l-value.
1977  if (E->getOpcode() == BO_Comma) {
1978    EmitIgnoredExpr(E->getLHS());
1979    EnsureInsertPoint();
1980    return EmitLValue(E->getRHS());
1981  }
1982
1983  if (E->getOpcode() == BO_PtrMemD ||
1984      E->getOpcode() == BO_PtrMemI)
1985    return EmitPointerToDataMemberBinaryExpr(E);
1986
1987  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
1988
1989  if (!hasAggregateLLVMType(E->getType())) {
1990    // __block variables need the RHS evaluated first.
1991    RValue RV = EmitAnyExpr(E->getRHS());
1992    LValue LV = EmitLValue(E->getLHS());
1993    EmitStoreThroughLValue(RV, LV, E->getType());
1994    return LV;
1995  }
1996
1997  if (E->getType()->isAnyComplexType())
1998    return EmitComplexAssignmentLValue(E);
1999
2000  return EmitAggExprToLValue(E);
2001}
2002
2003LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
2004  RValue RV = EmitCallExpr(E);
2005
2006  if (!RV.isScalar())
2007    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2008
2009  assert(E->getCallReturnType()->isReferenceType() &&
2010         "Can't have a scalar return unless the return type is a "
2011         "reference type!");
2012
2013  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2014}
2015
2016LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
2017  // FIXME: This shouldn't require another copy.
2018  return EmitAggExprToLValue(E);
2019}
2020
2021LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
2022  assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
2023         && "binding l-value to type which needs a temporary");
2024  AggValueSlot Slot = CreateAggTemp(E->getType(), "tmp");
2025  EmitCXXConstructExpr(E, Slot);
2026  return MakeAddrLValue(Slot.getAddr(), E->getType());
2027}
2028
2029LValue
2030CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
2031  return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
2032}
2033
2034LValue
2035CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
2036  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
2037  Slot.setLifetimeExternallyManaged();
2038  EmitAggExpr(E->getSubExpr(), Slot);
2039  EmitCXXTemporary(E->getTemporary(), Slot.getAddr());
2040  return MakeAddrLValue(Slot.getAddr(), E->getType());
2041}
2042
2043LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
2044  RValue RV = EmitObjCMessageExpr(E);
2045
2046  if (!RV.isScalar())
2047    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2048
2049  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2050         "Can't have a scalar return unless the return type is a "
2051         "reference type!");
2052
2053  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2054}
2055
2056LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2057  llvm::Value *V =
2058    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2059  return MakeAddrLValue(V, E->getType());
2060}
2061
2062llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2063                                             const ObjCIvarDecl *Ivar) {
2064  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2065}
2066
2067LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2068                                          llvm::Value *BaseValue,
2069                                          const ObjCIvarDecl *Ivar,
2070                                          unsigned CVRQualifiers) {
2071  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2072                                                   Ivar, CVRQualifiers);
2073}
2074
2075LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2076  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2077  llvm::Value *BaseValue = 0;
2078  const Expr *BaseExpr = E->getBase();
2079  Qualifiers BaseQuals;
2080  QualType ObjectTy;
2081  if (E->isArrow()) {
2082    BaseValue = EmitScalarExpr(BaseExpr);
2083    ObjectTy = BaseExpr->getType()->getPointeeType();
2084    BaseQuals = ObjectTy.getQualifiers();
2085  } else {
2086    LValue BaseLV = EmitLValue(BaseExpr);
2087    // FIXME: this isn't right for bitfields.
2088    BaseValue = BaseLV.getAddress();
2089    ObjectTy = BaseExpr->getType();
2090    BaseQuals = ObjectTy.getQualifiers();
2091  }
2092
2093  LValue LV =
2094    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2095                      BaseQuals.getCVRQualifiers());
2096  setObjCGCLValueClass(getContext(), E, LV);
2097  return LV;
2098}
2099
2100LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2101  // Can only get l-value for message expression returning aggregate type
2102  RValue RV = EmitAnyExprToTemp(E);
2103  return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2104}
2105
2106RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2107                                 ReturnValueSlot ReturnValue,
2108                                 CallExpr::const_arg_iterator ArgBeg,
2109                                 CallExpr::const_arg_iterator ArgEnd,
2110                                 const Decl *TargetDecl) {
2111  // Get the actual function type. The callee type will always be a pointer to
2112  // function type or a block pointer type.
2113  assert(CalleeType->isFunctionPointerType() &&
2114         "Call must have function pointer type!");
2115
2116  CalleeType = getContext().getCanonicalType(CalleeType);
2117
2118  const FunctionType *FnType
2119    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2120
2121  CallArgList Args;
2122  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2123
2124  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2125                  Callee, ReturnValue, Args, TargetDecl);
2126}
2127
2128LValue CodeGenFunction::
2129EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2130  llvm::Value *BaseV;
2131  if (E->getOpcode() == BO_PtrMemI)
2132    BaseV = EmitScalarExpr(E->getLHS());
2133  else
2134    BaseV = EmitLValue(E->getLHS()).getAddress();
2135
2136  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2137
2138  const MemberPointerType *MPT
2139    = E->getRHS()->getType()->getAs<MemberPointerType>();
2140
2141  llvm::Value *AddV =
2142    CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT);
2143
2144  return MakeAddrLValue(AddV, MPT->getPointeeType());
2145}
2146