CGExpr.cpp revision 28ebde58dd94b5ed2a6d149251202ab2c602a4a6 
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 "CGDebugInfo.h"
19#include "CGRecordLayout.h"
20#include "CGObjCRuntime.h"
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/DeclObjC.h"
23#include "llvm/Intrinsics.h"
24#include "clang/Frontend/CodeGenOptions.h"
25#include "llvm/Target/TargetData.h"
26using namespace clang;
27using namespace CodeGen;
28
29//===--------------------------------------------------------------------===//
30//                        Miscellaneous Helper Methods
31//===--------------------------------------------------------------------===//
32
33llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
34  unsigned addressSpace =
35    cast<llvm::PointerType>(value->getType())->getAddressSpace();
36
37  const llvm::PointerType *destType = Int8PtrTy;
38  if (addressSpace)
39    destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
40
41  if (value->getType() == destType) return value;
42  return Builder.CreateBitCast(value, destType);
43}
44
45/// CreateTempAlloca - This creates a alloca and inserts it into the entry
46/// block.
47llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
48                                                    const llvm::Twine &Name) {
49  if (!Builder.isNamePreserving())
50    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
51  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
52}
53
54void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
55                                     llvm::Value *Init) {
56  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
57  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
58  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
59}
60
61llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
62                                                const llvm::Twine &Name) {
63  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
64  // FIXME: Should we prefer the preferred type alignment here?
65  CharUnits Align = getContext().getTypeAlignInChars(Ty);
66  Alloc->setAlignment(Align.getQuantity());
67  return Alloc;
68}
69
70llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
71                                                 const llvm::Twine &Name) {
72  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
73  // FIXME: Should we prefer the preferred type alignment here?
74  CharUnits Align = getContext().getTypeAlignInChars(Ty);
75  Alloc->setAlignment(Align.getQuantity());
76  return Alloc;
77}
78
79/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
80/// expression and compare the result against zero, returning an Int1Ty value.
81llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
82  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
83    llvm::Value *MemPtr = EmitScalarExpr(E);
84    return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
85  }
86
87  QualType BoolTy = getContext().BoolTy;
88  if (!E->getType()->isAnyComplexType())
89    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
90
91  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
92}
93
94/// EmitIgnoredExpr - Emit code to compute the specified expression,
95/// ignoring the result.
96void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
97  if (E->isRValue())
98    return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
99
100  // Just emit it as an l-value and drop the result.
101  EmitLValue(E);
102}
103
104/// EmitAnyExpr - Emit code to compute the specified expression which
105/// can have any type.  The result is returned as an RValue struct.
106/// If this is an aggregate expression, AggSlot indicates where the
107/// result should be returned.
108RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot,
109                                    bool IgnoreResult) {
110  if (!hasAggregateLLVMType(E->getType()))
111    return RValue::get(EmitScalarExpr(E, IgnoreResult));
112  else if (E->getType()->isAnyComplexType())
113    return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult));
114
115  EmitAggExpr(E, AggSlot, IgnoreResult);
116  return AggSlot.asRValue();
117}
118
119/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
120/// always be accessible even if no aggregate location is provided.
121RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
122  AggValueSlot AggSlot = AggValueSlot::ignored();
123
124  if (hasAggregateLLVMType(E->getType()) &&
125      !E->getType()->isAnyComplexType())
126    AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
127  return EmitAnyExpr(E, AggSlot);
128}
129
130/// EmitAnyExprToMem - Evaluate an expression into a given memory
131/// location.
132void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
133                                       llvm::Value *Location,
134                                       bool IsLocationVolatile,
135                                       bool IsInit) {
136  if (E->getType()->isComplexType())
137    EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
138  else if (hasAggregateLLVMType(E->getType()))
139    EmitAggExpr(E, AggValueSlot::forAddr(Location, IsLocationVolatile, IsInit));
140  else {
141    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
142    LValue LV = MakeAddrLValue(Location, E->getType());
143    EmitStoreThroughLValue(RV, LV, E->getType());
144  }
145}
146
147namespace {
148/// \brief An adjustment to be made to the temporary created when emitting a
149/// reference binding, which accesses a particular subobject of that temporary.
150  struct SubobjectAdjustment {
151    enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
152
153    union {
154      struct {
155        const CastExpr *BasePath;
156        const CXXRecordDecl *DerivedClass;
157      } DerivedToBase;
158
159      FieldDecl *Field;
160    };
161
162    SubobjectAdjustment(const CastExpr *BasePath,
163                        const CXXRecordDecl *DerivedClass)
164      : Kind(DerivedToBaseAdjustment) {
165      DerivedToBase.BasePath = BasePath;
166      DerivedToBase.DerivedClass = DerivedClass;
167    }
168
169    SubobjectAdjustment(FieldDecl *Field)
170      : Kind(FieldAdjustment) {
171      this->Field = Field;
172    }
173  };
174}
175
176static llvm::Value *
177CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
178                         const NamedDecl *InitializedDecl) {
179  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
180    if (VD->hasGlobalStorage()) {
181      llvm::SmallString<256> Name;
182      llvm::raw_svector_ostream Out(Name);
183      CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out);
184      Out.flush();
185
186      const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
187
188      // Create the reference temporary.
189      llvm::GlobalValue *RefTemp =
190        new llvm::GlobalVariable(CGF.CGM.getModule(),
191                                 RefTempTy, /*isConstant=*/false,
192                                 llvm::GlobalValue::InternalLinkage,
193                                 llvm::Constant::getNullValue(RefTempTy),
194                                 Name.str());
195      return RefTemp;
196    }
197  }
198
199  return CGF.CreateMemTemp(Type, "ref.tmp");
200}
201
202static llvm::Value *
203EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
204                            llvm::Value *&ReferenceTemporary,
205                            const CXXDestructorDecl *&ReferenceTemporaryDtor,
206                            const NamedDecl *InitializedDecl) {
207  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
208    E = DAE->getExpr();
209
210  if (const ExprWithCleanups *TE = dyn_cast<ExprWithCleanups>(E)) {
211    CodeGenFunction::RunCleanupsScope Scope(CGF);
212
213    return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
214                                       ReferenceTemporary,
215                                       ReferenceTemporaryDtor,
216                                       InitializedDecl);
217  }
218
219  if (const ObjCPropertyRefExpr *PRE =
220      dyn_cast<ObjCPropertyRefExpr>(E->IgnoreParenImpCasts()))
221    if (PRE->getGetterResultType()->isReferenceType())
222      E = PRE;
223
224  RValue RV;
225  if (E->isGLValue()) {
226    // Emit the expression as an lvalue.
227    LValue LV = CGF.EmitLValue(E);
228    if (LV.isPropertyRef()) {
229      RV = CGF.EmitLoadOfPropertyRefLValue(LV);
230      return RV.getScalarVal();
231    }
232    if (LV.isSimple())
233      return LV.getAddress();
234
235    // We have to load the lvalue.
236    RV = CGF.EmitLoadOfLValue(LV, E->getType());
237  } else {
238    QualType ResultTy = E->getType();
239
240    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
241    while (true) {
242      E = E->IgnoreParens();
243
244      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
245        if ((CE->getCastKind() == CK_DerivedToBase ||
246             CE->getCastKind() == CK_UncheckedDerivedToBase) &&
247            E->getType()->isRecordType()) {
248          E = CE->getSubExpr();
249          CXXRecordDecl *Derived
250            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
251          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
252          continue;
253        }
254
255        if (CE->getCastKind() == CK_NoOp) {
256          E = CE->getSubExpr();
257          continue;
258        }
259      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
260        if (!ME->isArrow() && ME->getBase()->isRValue()) {
261          assert(ME->getBase()->getType()->isRecordType());
262          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
263            E = ME->getBase();
264            Adjustments.push_back(SubobjectAdjustment(Field));
265            continue;
266          }
267        }
268      }
269
270      if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
271        if (opaque->getType()->isRecordType())
272          return CGF.EmitOpaqueValueLValue(opaque).getAddress();
273
274      // Nothing changed.
275      break;
276    }
277
278    // Create a reference temporary if necessary.
279    AggValueSlot AggSlot = AggValueSlot::ignored();
280    if (CGF.hasAggregateLLVMType(E->getType()) &&
281        !E->getType()->isAnyComplexType()) {
282      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
283                                                    InitializedDecl);
284      AggSlot = AggValueSlot::forAddr(ReferenceTemporary, false,
285                                      InitializedDecl != 0);
286    }
287
288    RV = CGF.EmitAnyExpr(E, AggSlot);
289
290    if (InitializedDecl) {
291      // Get the destructor for the reference temporary.
292      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
293        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
294        if (!ClassDecl->hasTrivialDestructor())
295          ReferenceTemporaryDtor = ClassDecl->getDestructor();
296      }
297    }
298
299    // Check if need to perform derived-to-base casts and/or field accesses, to
300    // get from the temporary object we created (and, potentially, for which we
301    // extended the lifetime) to the subobject we're binding the reference to.
302    if (!Adjustments.empty()) {
303      llvm::Value *Object = RV.getAggregateAddr();
304      for (unsigned I = Adjustments.size(); I != 0; --I) {
305        SubobjectAdjustment &Adjustment = Adjustments[I-1];
306        switch (Adjustment.Kind) {
307        case SubobjectAdjustment::DerivedToBaseAdjustment:
308          Object =
309              CGF.GetAddressOfBaseClass(Object,
310                                        Adjustment.DerivedToBase.DerivedClass,
311                              Adjustment.DerivedToBase.BasePath->path_begin(),
312                              Adjustment.DerivedToBase.BasePath->path_end(),
313                                        /*NullCheckValue=*/false);
314          break;
315
316        case SubobjectAdjustment::FieldAdjustment: {
317          LValue LV =
318            CGF.EmitLValueForField(Object, Adjustment.Field, 0);
319          if (LV.isSimple()) {
320            Object = LV.getAddress();
321            break;
322          }
323
324          // For non-simple lvalues, we actually have to create a copy of
325          // the object we're binding to.
326          QualType T = Adjustment.Field->getType().getNonReferenceType()
327                                                  .getUnqualifiedType();
328          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
329          LValue TempLV = CGF.MakeAddrLValue(Object,
330                                             Adjustment.Field->getType());
331          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV, T), TempLV, T);
332          break;
333        }
334
335        }
336      }
337
338      return Object;
339    }
340  }
341
342  if (RV.isAggregate())
343    return RV.getAggregateAddr();
344
345  // Create a temporary variable that we can bind the reference to.
346  ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
347                                                InitializedDecl);
348
349
350  unsigned Alignment =
351    CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
352  if (RV.isScalar())
353    CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
354                          /*Volatile=*/false, Alignment, E->getType());
355  else
356    CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
357                           /*Volatile=*/false);
358  return ReferenceTemporary;
359}
360
361RValue
362CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E,
363                                            const NamedDecl *InitializedDecl) {
364  llvm::Value *ReferenceTemporary = 0;
365  const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
366  llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
367                                                   ReferenceTemporaryDtor,
368                                                   InitializedDecl);
369  if (!ReferenceTemporaryDtor)
370    return RValue::get(Value);
371
372  // Make sure to call the destructor for the reference temporary.
373  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
374    if (VD->hasGlobalStorage()) {
375      llvm::Constant *DtorFn =
376        CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
377      EmitCXXGlobalDtorRegistration(DtorFn,
378                                    cast<llvm::Constant>(ReferenceTemporary));
379
380      return RValue::get(Value);
381    }
382  }
383
384  PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
385
386  return RValue::get(Value);
387}
388
389
390/// getAccessedFieldNo - Given an encoded value and a result number, return the
391/// input field number being accessed.
392unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
393                                             const llvm::Constant *Elts) {
394  if (isa<llvm::ConstantAggregateZero>(Elts))
395    return 0;
396
397  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
398}
399
400void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
401  if (!CatchUndefined)
402    return;
403
404  // This needs to be to the standard address space.
405  Address = Builder.CreateBitCast(Address, Int8PtrTy);
406
407  const llvm::Type *IntPtrT = IntPtrTy;
408  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
409
410  // In time, people may want to control this and use a 1 here.
411  llvm::Value *Arg = Builder.getFalse();
412  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
413  llvm::BasicBlock *Cont = createBasicBlock();
414  llvm::BasicBlock *Check = createBasicBlock();
415  llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
416  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
417
418  EmitBlock(Check);
419  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
420                                        llvm::ConstantInt::get(IntPtrTy, Size)),
421                       Cont, getTrapBB());
422  EmitBlock(Cont);
423}
424
425
426CodeGenFunction::ComplexPairTy CodeGenFunction::
427EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
428                         bool isInc, bool isPre) {
429  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
430                                            LV.isVolatileQualified());
431
432  llvm::Value *NextVal;
433  if (isa<llvm::IntegerType>(InVal.first->getType())) {
434    uint64_t AmountVal = isInc ? 1 : -1;
435    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
436
437    // Add the inc/dec to the real part.
438    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
439  } else {
440    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
441    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
442    if (!isInc)
443      FVal.changeSign();
444    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
445
446    // Add the inc/dec to the real part.
447    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
448  }
449
450  ComplexPairTy IncVal(NextVal, InVal.second);
451
452  // Store the updated result through the lvalue.
453  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
454
455  // If this is a postinc, return the value read from memory, otherwise use the
456  // updated value.
457  return isPre ? IncVal : InVal;
458}
459
460
461//===----------------------------------------------------------------------===//
462//                         LValue Expression Emission
463//===----------------------------------------------------------------------===//
464
465RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
466  if (Ty->isVoidType())
467    return RValue::get(0);
468
469  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
470    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
471    llvm::Value *U = llvm::UndefValue::get(EltTy);
472    return RValue::getComplex(std::make_pair(U, U));
473  }
474
475  // If this is a use of an undefined aggregate type, the aggregate must have an
476  // identifiable address.  Just because the contents of the value are undefined
477  // doesn't mean that the address can't be taken and compared.
478  if (hasAggregateLLVMType(Ty)) {
479    llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
480    return RValue::getAggregate(DestPtr);
481  }
482
483  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
484}
485
486RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
487                                              const char *Name) {
488  ErrorUnsupported(E, Name);
489  return GetUndefRValue(E->getType());
490}
491
492LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
493                                              const char *Name) {
494  ErrorUnsupported(E, Name);
495  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
496  return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType());
497}
498
499LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
500  LValue LV = EmitLValue(E);
501  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
502    EmitCheck(LV.getAddress(),
503              getContext().getTypeSizeInChars(E->getType()).getQuantity());
504  return LV;
505}
506
507/// EmitLValue - Emit code to compute a designator that specifies the location
508/// of the expression.
509///
510/// This can return one of two things: a simple address or a bitfield reference.
511/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
512/// an LLVM pointer type.
513///
514/// If this returns a bitfield reference, nothing about the pointee type of the
515/// LLVM value is known: For example, it may not be a pointer to an integer.
516///
517/// If this returns a normal address, and if the lvalue's C type is fixed size,
518/// this method guarantees that the returned pointer type will point to an LLVM
519/// type of the same size of the lvalue's type.  If the lvalue has a variable
520/// length type, this is not possible.
521///
522LValue CodeGenFunction::EmitLValue(const Expr *E) {
523  switch (E->getStmtClass()) {
524  default: return EmitUnsupportedLValue(E, "l-value expression");
525
526  case Expr::ObjCSelectorExprClass:
527  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
528  case Expr::ObjCIsaExprClass:
529    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
530  case Expr::BinaryOperatorClass:
531    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
532  case Expr::CompoundAssignOperatorClass:
533    if (!E->getType()->isAnyComplexType())
534      return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
535    return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
536  case Expr::CallExprClass:
537  case Expr::CXXMemberCallExprClass:
538  case Expr::CXXOperatorCallExprClass:
539    return EmitCallExprLValue(cast<CallExpr>(E));
540  case Expr::VAArgExprClass:
541    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
542  case Expr::DeclRefExprClass:
543    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
544  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
545  case Expr::GenericSelectionExprClass:
546    return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
547  case Expr::PredefinedExprClass:
548    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
549  case Expr::StringLiteralClass:
550    return EmitStringLiteralLValue(cast<StringLiteral>(E));
551  case Expr::ObjCEncodeExprClass:
552    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
553
554  case Expr::BlockDeclRefExprClass:
555    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
556
557  case Expr::CXXTemporaryObjectExprClass:
558  case Expr::CXXConstructExprClass:
559    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
560  case Expr::CXXBindTemporaryExprClass:
561    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
562  case Expr::ExprWithCleanupsClass:
563    return EmitExprWithCleanupsLValue(cast<ExprWithCleanups>(E));
564  case Expr::CXXScalarValueInitExprClass:
565    return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
566  case Expr::CXXDefaultArgExprClass:
567    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
568  case Expr::CXXTypeidExprClass:
569    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
570
571  case Expr::ObjCMessageExprClass:
572    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
573  case Expr::ObjCIvarRefExprClass:
574    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
575  case Expr::ObjCPropertyRefExprClass:
576    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
577  case Expr::StmtExprClass:
578    return EmitStmtExprLValue(cast<StmtExpr>(E));
579  case Expr::UnaryOperatorClass:
580    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
581  case Expr::ArraySubscriptExprClass:
582    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
583  case Expr::ExtVectorElementExprClass:
584    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
585  case Expr::MemberExprClass:
586    return EmitMemberExpr(cast<MemberExpr>(E));
587  case Expr::CompoundLiteralExprClass:
588    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
589  case Expr::ConditionalOperatorClass:
590    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
591  case Expr::BinaryConditionalOperatorClass:
592    return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
593  case Expr::ChooseExprClass:
594    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
595  case Expr::OpaqueValueExprClass:
596    return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
597  case Expr::ImplicitCastExprClass:
598  case Expr::CStyleCastExprClass:
599  case Expr::CXXFunctionalCastExprClass:
600  case Expr::CXXStaticCastExprClass:
601  case Expr::CXXDynamicCastExprClass:
602  case Expr::CXXReinterpretCastExprClass:
603  case Expr::CXXConstCastExprClass:
604    return EmitCastLValue(cast<CastExpr>(E));
605  }
606}
607
608llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
609                                              unsigned Alignment, QualType Ty,
610                                              llvm::MDNode *TBAAInfo) {
611  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
612  if (Volatile)
613    Load->setVolatile(true);
614  if (Alignment)
615    Load->setAlignment(Alignment);
616  if (TBAAInfo)
617    CGM.DecorateInstruction(Load, TBAAInfo);
618
619  return EmitFromMemory(Load, Ty);
620}
621
622static bool isBooleanUnderlyingType(QualType Ty) {
623  if (const EnumType *ET = dyn_cast<EnumType>(Ty))
624    return ET->getDecl()->getIntegerType()->isBooleanType();
625  return false;
626}
627
628llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
629  // Bool has a different representation in memory than in registers.
630  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
631    // This should really always be an i1, but sometimes it's already
632    // an i8, and it's awkward to track those cases down.
633    if (Value->getType()->isIntegerTy(1))
634      return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool");
635    assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8");
636  }
637
638  return Value;
639}
640
641llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
642  // Bool has a different representation in memory than in registers.
643  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
644    assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8");
645    return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
646  }
647
648  return Value;
649}
650
651void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
652                                        bool Volatile, unsigned Alignment,
653                                        QualType Ty,
654                                        llvm::MDNode *TBAAInfo) {
655  Value = EmitToMemory(Value, Ty);
656  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
657  if (Alignment)
658    Store->setAlignment(Alignment);
659  if (TBAAInfo)
660    CGM.DecorateInstruction(Store, TBAAInfo);
661}
662
663/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
664/// method emits the address of the lvalue, then loads the result as an rvalue,
665/// returning the rvalue.
666RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
667  if (LV.isObjCWeak()) {
668    // load of a __weak object.
669    llvm::Value *AddrWeakObj = LV.getAddress();
670    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
671                                                             AddrWeakObj));
672  }
673
674  if (LV.isSimple()) {
675    llvm::Value *Ptr = LV.getAddress();
676
677    // Functions are l-values that don't require loading.
678    if (ExprType->isFunctionType())
679      return RValue::get(Ptr);
680
681    // Everything needs a load.
682    return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
683                                        LV.getAlignment(), ExprType,
684                                        LV.getTBAAInfo()));
685
686  }
687
688  if (LV.isVectorElt()) {
689    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
690                                          LV.isVolatileQualified(), "tmp");
691    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
692                                                    "vecext"));
693  }
694
695  // If this is a reference to a subset of the elements of a vector, either
696  // shuffle the input or extract/insert them as appropriate.
697  if (LV.isExtVectorElt())
698    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
699
700  if (LV.isBitField())
701    return EmitLoadOfBitfieldLValue(LV, ExprType);
702
703  assert(LV.isPropertyRef() && "Unknown LValue type!");
704  return EmitLoadOfPropertyRefLValue(LV);
705}
706
707RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
708                                                 QualType ExprType) {
709  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
710
711  // Get the output type.
712  const llvm::Type *ResLTy = ConvertType(ExprType);
713  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
714
715  // Compute the result as an OR of all of the individual component accesses.
716  llvm::Value *Res = 0;
717  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
718    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
719
720    // Get the field pointer.
721    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
722
723    // Only offset by the field index if used, so that incoming values are not
724    // required to be structures.
725    if (AI.FieldIndex)
726      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
727
728    // Offset by the byte offset, if used.
729    if (!AI.FieldByteOffset.isZero()) {
730      Ptr = EmitCastToVoidPtr(Ptr);
731      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(),
732                                       "bf.field.offs");
733    }
734
735    // Cast to the access type.
736    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(getLLVMContext(),
737                                                     AI.AccessWidth,
738                              CGM.getContext().getTargetAddressSpace(ExprType));
739    Ptr = Builder.CreateBitCast(Ptr, PTy);
740
741    // Perform the load.
742    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
743    if (AI.AccessAlignment)
744      Load->setAlignment(AI.AccessAlignment);
745
746    // Shift out unused low bits and mask out unused high bits.
747    llvm::Value *Val = Load;
748    if (AI.FieldBitStart)
749      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
750    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
751                                                            AI.TargetBitWidth),
752                            "bf.clear");
753
754    // Extend or truncate to the target size.
755    if (AI.AccessWidth < ResSizeInBits)
756      Val = Builder.CreateZExt(Val, ResLTy);
757    else if (AI.AccessWidth > ResSizeInBits)
758      Val = Builder.CreateTrunc(Val, ResLTy);
759
760    // Shift into place, and OR into the result.
761    if (AI.TargetBitOffset)
762      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
763    Res = Res ? Builder.CreateOr(Res, Val) : Val;
764  }
765
766  // If the bit-field is signed, perform the sign-extension.
767  //
768  // FIXME: This can easily be folded into the load of the high bits, which
769  // could also eliminate the mask of high bits in some situations.
770  if (Info.isSigned()) {
771    unsigned ExtraBits = ResSizeInBits - Info.getSize();
772    if (ExtraBits)
773      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
774                               ExtraBits, "bf.val.sext");
775  }
776
777  return RValue::get(Res);
778}
779
780// If this is a reference to a subset of the elements of a vector, create an
781// appropriate shufflevector.
782RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
783                                                         QualType ExprType) {
784  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
785                                        LV.isVolatileQualified(), "tmp");
786
787  const llvm::Constant *Elts = LV.getExtVectorElts();
788
789  // If the result of the expression is a non-vector type, we must be extracting
790  // a single element.  Just codegen as an extractelement.
791  const VectorType *ExprVT = ExprType->getAs<VectorType>();
792  if (!ExprVT) {
793    unsigned InIdx = getAccessedFieldNo(0, Elts);
794    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
795    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
796  }
797
798  // Always use shuffle vector to try to retain the original program structure
799  unsigned NumResultElts = ExprVT->getNumElements();
800
801  llvm::SmallVector<llvm::Constant*, 4> Mask;
802  for (unsigned i = 0; i != NumResultElts; ++i) {
803    unsigned InIdx = getAccessedFieldNo(i, Elts);
804    Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx));
805  }
806
807  llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
808  Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
809                                    MaskV, "tmp");
810  return RValue::get(Vec);
811}
812
813
814
815/// EmitStoreThroughLValue - Store the specified rvalue into the specified
816/// lvalue, where both are guaranteed to the have the same type, and that type
817/// is 'Ty'.
818void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
819                                             QualType Ty) {
820  if (!Dst.isSimple()) {
821    if (Dst.isVectorElt()) {
822      // Read/modify/write the vector, inserting the new element.
823      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
824                                            Dst.isVolatileQualified(), "tmp");
825      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
826                                        Dst.getVectorIdx(), "vecins");
827      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
828      return;
829    }
830
831    // If this is an update of extended vector elements, insert them as
832    // appropriate.
833    if (Dst.isExtVectorElt())
834      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
835
836    if (Dst.isBitField())
837      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
838
839    assert(Dst.isPropertyRef() && "Unknown LValue type");
840    return EmitStoreThroughPropertyRefLValue(Src, Dst);
841  }
842
843  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
844    // load of a __weak object.
845    llvm::Value *LvalueDst = Dst.getAddress();
846    llvm::Value *src = Src.getScalarVal();
847     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
848    return;
849  }
850
851  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
852    // load of a __strong object.
853    llvm::Value *LvalueDst = Dst.getAddress();
854    llvm::Value *src = Src.getScalarVal();
855    if (Dst.isObjCIvar()) {
856      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
857      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
858      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
859      llvm::Value *dst = RHS;
860      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
861      llvm::Value *LHS =
862        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
863      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
864      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
865                                              BytesBetween);
866    } else if (Dst.isGlobalObjCRef()) {
867      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
868                                                Dst.isThreadLocalRef());
869    }
870    else
871      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
872    return;
873  }
874
875  assert(Src.isScalar() && "Can't emit an agg store with this method");
876  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
877                    Dst.isVolatileQualified(), Dst.getAlignment(), Ty,
878                    Dst.getTBAAInfo());
879}
880
881void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
882                                                     QualType Ty,
883                                                     llvm::Value **Result) {
884  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
885
886  // Get the output type.
887  const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
888  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
889
890  // Get the source value, truncated to the width of the bit-field.
891  llvm::Value *SrcVal = Src.getScalarVal();
892
893  if (Ty->isBooleanType())
894    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
895
896  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
897                                                                Info.getSize()),
898                             "bf.value");
899
900  // Return the new value of the bit-field, if requested.
901  if (Result) {
902    // Cast back to the proper type for result.
903    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
904    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
905                                                   "bf.reload.val");
906
907    // Sign extend if necessary.
908    if (Info.isSigned()) {
909      unsigned ExtraBits = ResSizeInBits - Info.getSize();
910      if (ExtraBits)
911        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
912                                       ExtraBits, "bf.reload.sext");
913    }
914
915    *Result = ReloadVal;
916  }
917
918  // Iterate over the components, writing each piece to memory.
919  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
920    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
921
922    // Get the field pointer.
923    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
924    unsigned addressSpace =
925      cast<llvm::PointerType>(Ptr->getType())->getAddressSpace();
926
927    // Only offset by the field index if used, so that incoming values are not
928    // required to be structures.
929    if (AI.FieldIndex)
930      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
931
932    // Offset by the byte offset, if used.
933    if (!AI.FieldByteOffset.isZero()) {
934      Ptr = EmitCastToVoidPtr(Ptr);
935      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(),
936                                       "bf.field.offs");
937    }
938
939    // Cast to the access type.
940    const llvm::Type *AccessLTy =
941      llvm::Type::getIntNTy(getLLVMContext(), AI.AccessWidth);
942
943    const llvm::Type *PTy = AccessLTy->getPointerTo(addressSpace);
944    Ptr = Builder.CreateBitCast(Ptr, PTy);
945
946    // Extract the piece of the bit-field value to write in this access, limited
947    // to the values that are part of this access.
948    llvm::Value *Val = SrcVal;
949    if (AI.TargetBitOffset)
950      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
951    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
952                                                            AI.TargetBitWidth));
953
954    // Extend or truncate to the access size.
955    if (ResSizeInBits < AI.AccessWidth)
956      Val = Builder.CreateZExt(Val, AccessLTy);
957    else if (ResSizeInBits > AI.AccessWidth)
958      Val = Builder.CreateTrunc(Val, AccessLTy);
959
960    // Shift into the position in memory.
961    if (AI.FieldBitStart)
962      Val = Builder.CreateShl(Val, AI.FieldBitStart);
963
964    // If necessary, load and OR in bits that are outside of the bit-field.
965    if (AI.TargetBitWidth != AI.AccessWidth) {
966      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
967      if (AI.AccessAlignment)
968        Load->setAlignment(AI.AccessAlignment);
969
970      // Compute the mask for zeroing the bits that are part of the bit-field.
971      llvm::APInt InvMask =
972        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
973                                 AI.FieldBitStart + AI.TargetBitWidth);
974
975      // Apply the mask and OR in to the value to write.
976      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
977    }
978
979    // Write the value.
980    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
981                                                 Dst.isVolatileQualified());
982    if (AI.AccessAlignment)
983      Store->setAlignment(AI.AccessAlignment);
984  }
985}
986
987void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
988                                                               LValue Dst,
989                                                               QualType Ty) {
990  // This access turns into a read/modify/write of the vector.  Load the input
991  // value now.
992  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
993                                        Dst.isVolatileQualified(), "tmp");
994  const llvm::Constant *Elts = Dst.getExtVectorElts();
995
996  llvm::Value *SrcVal = Src.getScalarVal();
997
998  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
999    unsigned NumSrcElts = VTy->getNumElements();
1000    unsigned NumDstElts =
1001       cast<llvm::VectorType>(Vec->getType())->getNumElements();
1002    if (NumDstElts == NumSrcElts) {
1003      // Use shuffle vector is the src and destination are the same number of
1004      // elements and restore the vector mask since it is on the side it will be
1005      // stored.
1006      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1007      for (unsigned i = 0; i != NumSrcElts; ++i) {
1008        unsigned InIdx = getAccessedFieldNo(i, Elts);
1009        Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
1010      }
1011
1012      llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1013      Vec = Builder.CreateShuffleVector(SrcVal,
1014                                        llvm::UndefValue::get(Vec->getType()),
1015                                        MaskV, "tmp");
1016    } else if (NumDstElts > NumSrcElts) {
1017      // Extended the source vector to the same length and then shuffle it
1018      // into the destination.
1019      // FIXME: since we're shuffling with undef, can we just use the indices
1020      //        into that?  This could be simpler.
1021      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1022      unsigned i;
1023      for (i = 0; i != NumSrcElts; ++i)
1024        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1025      for (; i != NumDstElts; ++i)
1026        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1027      llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1028      llvm::Value *ExtSrcVal =
1029        Builder.CreateShuffleVector(SrcVal,
1030                                    llvm::UndefValue::get(SrcVal->getType()),
1031                                    ExtMaskV, "tmp");
1032      // build identity
1033      llvm::SmallVector<llvm::Constant*, 4> Mask;
1034      for (unsigned i = 0; i != NumDstElts; ++i)
1035        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1036
1037      // modify when what gets shuffled in
1038      for (unsigned i = 0; i != NumSrcElts; ++i) {
1039        unsigned Idx = getAccessedFieldNo(i, Elts);
1040        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
1041      }
1042      llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1043      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
1044    } else {
1045      // We should never shorten the vector
1046      assert(0 && "unexpected shorten vector length");
1047    }
1048  } else {
1049    // If the Src is a scalar (not a vector) it must be updating one element.
1050    unsigned InIdx = getAccessedFieldNo(0, Elts);
1051    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
1052    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
1053  }
1054
1055  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
1056}
1057
1058// setObjCGCLValueClass - sets class of he lvalue for the purpose of
1059// generating write-barries API. It is currently a global, ivar,
1060// or neither.
1061static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1062                                 LValue &LV) {
1063  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
1064    return;
1065
1066  if (isa<ObjCIvarRefExpr>(E)) {
1067    LV.setObjCIvar(true);
1068    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
1069    LV.setBaseIvarExp(Exp->getBase());
1070    LV.setObjCArray(E->getType()->isArrayType());
1071    return;
1072  }
1073
1074  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
1075    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1076      if (VD->hasGlobalStorage()) {
1077        LV.setGlobalObjCRef(true);
1078        LV.setThreadLocalRef(VD->isThreadSpecified());
1079      }
1080    }
1081    LV.setObjCArray(E->getType()->isArrayType());
1082    return;
1083  }
1084
1085  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
1086    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1087    return;
1088  }
1089
1090  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
1091    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1092    if (LV.isObjCIvar()) {
1093      // If cast is to a structure pointer, follow gcc's behavior and make it
1094      // a non-ivar write-barrier.
1095      QualType ExpTy = E->getType();
1096      if (ExpTy->isPointerType())
1097        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1098      if (ExpTy->isRecordType())
1099        LV.setObjCIvar(false);
1100    }
1101    return;
1102  }
1103
1104  if (const GenericSelectionExpr *Exp = dyn_cast<GenericSelectionExpr>(E)) {
1105    setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
1106    return;
1107  }
1108
1109  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1110    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1111    return;
1112  }
1113
1114  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1115    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1116    return;
1117  }
1118
1119  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1120    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1121    if (LV.isObjCIvar() && !LV.isObjCArray())
1122      // Using array syntax to assigning to what an ivar points to is not
1123      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1124      LV.setObjCIvar(false);
1125    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1126      // Using array syntax to assigning to what global points to is not
1127      // same as assigning to the global itself. {id *G;} G[i] = 0;
1128      LV.setGlobalObjCRef(false);
1129    return;
1130  }
1131
1132  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1133    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1134    // We don't know if member is an 'ivar', but this flag is looked at
1135    // only in the context of LV.isObjCIvar().
1136    LV.setObjCArray(E->getType()->isArrayType());
1137    return;
1138  }
1139}
1140
1141static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1142                                      const Expr *E, const VarDecl *VD) {
1143  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1144         "Var decl must have external storage or be a file var decl!");
1145
1146  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1147  if (VD->getType()->isReferenceType())
1148    V = CGF.Builder.CreateLoad(V, "tmp");
1149  unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity();
1150  LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment);
1151  setObjCGCLValueClass(CGF.getContext(), E, LV);
1152  return LV;
1153}
1154
1155static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1156                                      const Expr *E, const FunctionDecl *FD) {
1157  llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
1158  if (!FD->hasPrototype()) {
1159    if (const FunctionProtoType *Proto =
1160            FD->getType()->getAs<FunctionProtoType>()) {
1161      // Ugly case: for a K&R-style definition, the type of the definition
1162      // isn't the same as the type of a use.  Correct for this with a
1163      // bitcast.
1164      QualType NoProtoType =
1165          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1166      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1167      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1168    }
1169  }
1170  unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity();
1171  return CGF.MakeAddrLValue(V, E->getType(), Alignment);
1172}
1173
1174LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1175  const NamedDecl *ND = E->getDecl();
1176  unsigned Alignment = getContext().getDeclAlign(ND).getQuantity();
1177
1178  if (ND->hasAttr<WeakRefAttr>()) {
1179    const ValueDecl *VD = cast<ValueDecl>(ND);
1180    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1181    return MakeAddrLValue(Aliasee, E->getType(), Alignment);
1182  }
1183
1184  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1185
1186    // Check if this is a global variable.
1187    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1188      return EmitGlobalVarDeclLValue(*this, E, VD);
1189
1190    bool NonGCable = VD->hasLocalStorage() &&
1191                     !VD->getType()->isReferenceType() &&
1192                     !VD->hasAttr<BlocksAttr>();
1193
1194    llvm::Value *V = LocalDeclMap[VD];
1195    if (!V && VD->isStaticLocal())
1196      V = CGM.getStaticLocalDeclAddress(VD);
1197    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1198
1199    if (VD->hasAttr<BlocksAttr>())
1200      V = BuildBlockByrefAddress(V, VD);
1201
1202    if (VD->getType()->isReferenceType())
1203      V = Builder.CreateLoad(V, "tmp");
1204
1205    LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
1206    if (NonGCable) {
1207      LV.getQuals().removeObjCGCAttr();
1208      LV.setNonGC(true);
1209    }
1210    setObjCGCLValueClass(getContext(), E, LV);
1211    return LV;
1212  }
1213
1214  if (const FunctionDecl *fn = dyn_cast<FunctionDecl>(ND))
1215    return EmitFunctionDeclLValue(*this, E, fn);
1216
1217  assert(false && "Unhandled DeclRefExpr");
1218
1219  // an invalid LValue, but the assert will
1220  // ensure that this point is never reached.
1221  return LValue();
1222}
1223
1224LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1225  unsigned Alignment =
1226    getContext().getDeclAlign(E->getDecl()).getQuantity();
1227  return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
1228}
1229
1230LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1231  // __extension__ doesn't affect lvalue-ness.
1232  if (E->getOpcode() == UO_Extension)
1233    return EmitLValue(E->getSubExpr());
1234
1235  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1236  switch (E->getOpcode()) {
1237  default: assert(0 && "Unknown unary operator lvalue!");
1238  case UO_Deref: {
1239    QualType T = E->getSubExpr()->getType()->getPointeeType();
1240    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1241
1242    LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
1243    LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
1244
1245    // We should not generate __weak write barrier on indirect reference
1246    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1247    // But, we continue to generate __strong write barrier on indirect write
1248    // into a pointer to object.
1249    if (getContext().getLangOptions().ObjC1 &&
1250        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1251        LV.isObjCWeak())
1252      LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1253    return LV;
1254  }
1255  case UO_Real:
1256  case UO_Imag: {
1257    LValue LV = EmitLValue(E->getSubExpr());
1258    assert(LV.isSimple() && "real/imag on non-ordinary l-value");
1259    llvm::Value *Addr = LV.getAddress();
1260
1261    // real and imag are valid on scalars.  This is a faster way of
1262    // testing that.
1263    if (!cast<llvm::PointerType>(Addr->getType())
1264           ->getElementType()->isStructTy()) {
1265      assert(E->getSubExpr()->getType()->isArithmeticType());
1266      return LV;
1267    }
1268
1269    assert(E->getSubExpr()->getType()->isAnyComplexType());
1270
1271    unsigned Idx = E->getOpcode() == UO_Imag;
1272    return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
1273                                                  Idx, "idx"),
1274                          ExprTy);
1275  }
1276  case UO_PreInc:
1277  case UO_PreDec: {
1278    LValue LV = EmitLValue(E->getSubExpr());
1279    bool isInc = E->getOpcode() == UO_PreInc;
1280
1281    if (E->getType()->isAnyComplexType())
1282      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1283    else
1284      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1285    return LV;
1286  }
1287  }
1288}
1289
1290LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1291  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
1292                        E->getType());
1293}
1294
1295LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1296  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1297                        E->getType());
1298}
1299
1300
1301LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1302  switch (E->getIdentType()) {
1303  default:
1304    return EmitUnsupportedLValue(E, "predefined expression");
1305
1306  case PredefinedExpr::Func:
1307  case PredefinedExpr::Function:
1308  case PredefinedExpr::PrettyFunction: {
1309    unsigned Type = E->getIdentType();
1310    std::string GlobalVarName;
1311
1312    switch (Type) {
1313    default: assert(0 && "Invalid type");
1314    case PredefinedExpr::Func:
1315      GlobalVarName = "__func__.";
1316      break;
1317    case PredefinedExpr::Function:
1318      GlobalVarName = "__FUNCTION__.";
1319      break;
1320    case PredefinedExpr::PrettyFunction:
1321      GlobalVarName = "__PRETTY_FUNCTION__.";
1322      break;
1323    }
1324
1325    llvm::StringRef FnName = CurFn->getName();
1326    if (FnName.startswith("\01"))
1327      FnName = FnName.substr(1);
1328    GlobalVarName += FnName;
1329
1330    const Decl *CurDecl = CurCodeDecl;
1331    if (CurDecl == 0)
1332      CurDecl = getContext().getTranslationUnitDecl();
1333
1334    std::string FunctionName =
1335        (isa<BlockDecl>(CurDecl)
1336         ? FnName.str()
1337         : PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl));
1338
1339    llvm::Constant *C =
1340      CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1341    return MakeAddrLValue(C, E->getType());
1342  }
1343  }
1344}
1345
1346llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1347  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1348
1349  // If we are not optimzing, don't collapse all calls to trap in the function
1350  // to the same call, that way, in the debugger they can see which operation
1351  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1352  // to just one per function to save on codesize.
1353  if (GCO.OptimizationLevel && TrapBB)
1354    return TrapBB;
1355
1356  llvm::BasicBlock *Cont = 0;
1357  if (HaveInsertPoint()) {
1358    Cont = createBasicBlock("cont");
1359    EmitBranch(Cont);
1360  }
1361  TrapBB = createBasicBlock("trap");
1362  EmitBlock(TrapBB);
1363
1364  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1365  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1366  TrapCall->setDoesNotReturn();
1367  TrapCall->setDoesNotThrow();
1368  Builder.CreateUnreachable();
1369
1370  if (Cont)
1371    EmitBlock(Cont);
1372  return TrapBB;
1373}
1374
1375/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1376/// array to pointer, return the array subexpression.
1377static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1378  // If this isn't just an array->pointer decay, bail out.
1379  const CastExpr *CE = dyn_cast<CastExpr>(E);
1380  if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay)
1381    return 0;
1382
1383  // If this is a decay from variable width array, bail out.
1384  const Expr *SubExpr = CE->getSubExpr();
1385  if (SubExpr->getType()->isVariableArrayType())
1386    return 0;
1387
1388  return SubExpr;
1389}
1390
1391LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1392  // The index must always be an integer, which is not an aggregate.  Emit it.
1393  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1394  QualType IdxTy  = E->getIdx()->getType();
1395  bool IdxSigned = IdxTy->isSignedIntegerType();
1396
1397  // If the base is a vector type, then we are forming a vector element lvalue
1398  // with this subscript.
1399  if (E->getBase()->getType()->isVectorType()) {
1400    // Emit the vector as an lvalue to get its address.
1401    LValue LHS = EmitLValue(E->getBase());
1402    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1403    Idx = Builder.CreateIntCast(Idx, Int32Ty, IdxSigned, "vidx");
1404    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1405                                 E->getBase()->getType().getCVRQualifiers());
1406  }
1407
1408  // Extend or truncate the index type to 32 or 64-bits.
1409  if (Idx->getType() != IntPtrTy)
1410    Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
1411
1412  // FIXME: As llvm implements the object size checking, this can come out.
1413  if (CatchUndefined) {
1414    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1415      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1416        if (ICE->getCastKind() == CK_ArrayToPointerDecay) {
1417          if (const ConstantArrayType *CAT
1418              = getContext().getAsConstantArrayType(DRE->getType())) {
1419            llvm::APInt Size = CAT->getSize();
1420            llvm::BasicBlock *Cont = createBasicBlock("cont");
1421            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1422                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1423                                 Cont, getTrapBB());
1424            EmitBlock(Cont);
1425          }
1426        }
1427      }
1428    }
1429  }
1430
1431  // We know that the pointer points to a type of the correct size, unless the
1432  // size is a VLA or Objective-C interface.
1433  llvm::Value *Address = 0;
1434  unsigned ArrayAlignment = 0;
1435  if (const VariableArrayType *VAT =
1436        getContext().getAsVariableArrayType(E->getType())) {
1437    llvm::Value *VLASize = GetVLASize(VAT);
1438
1439    Idx = Builder.CreateMul(Idx, VLASize);
1440
1441    // The base must be a pointer, which is not an aggregate.  Emit it.
1442    llvm::Value *Base = EmitScalarExpr(E->getBase());
1443
1444    Address = EmitCastToVoidPtr(Base);
1445    if (getContext().getLangOptions().isSignedOverflowDefined())
1446      Address = Builder.CreateGEP(Address, Idx, "arrayidx");
1447    else
1448      Address = Builder.CreateInBoundsGEP(Address, Idx, "arrayidx");
1449    Address = Builder.CreateBitCast(Address, Base->getType());
1450  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1451    // Indexing over an interface, as in "NSString *P; P[4];"
1452    llvm::Value *InterfaceSize =
1453      llvm::ConstantInt::get(Idx->getType(),
1454          getContext().getTypeSizeInChars(OIT).getQuantity());
1455
1456    Idx = Builder.CreateMul(Idx, InterfaceSize);
1457
1458    // The base must be a pointer, which is not an aggregate.  Emit it.
1459    llvm::Value *Base = EmitScalarExpr(E->getBase());
1460    Address = EmitCastToVoidPtr(Base);
1461    Address = Builder.CreateGEP(Address, Idx, "arrayidx");
1462    Address = Builder.CreateBitCast(Address, Base->getType());
1463  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1464    // If this is A[i] where A is an array, the frontend will have decayed the
1465    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1466    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1467    // "gep x, i" here.  Emit one "gep A, 0, i".
1468    assert(Array->getType()->isArrayType() &&
1469           "Array to pointer decay must have array source type!");
1470    LValue ArrayLV = EmitLValue(Array);
1471    llvm::Value *ArrayPtr = ArrayLV.getAddress();
1472    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1473    llvm::Value *Args[] = { Zero, Idx };
1474
1475    // Propagate the alignment from the array itself to the result.
1476    ArrayAlignment = ArrayLV.getAlignment();
1477
1478    if (getContext().getLangOptions().isSignedOverflowDefined())
1479      Address = Builder.CreateGEP(ArrayPtr, Args, Args+2, "arrayidx");
1480    else
1481      Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1482  } else {
1483    // The base must be a pointer, which is not an aggregate.  Emit it.
1484    llvm::Value *Base = EmitScalarExpr(E->getBase());
1485    if (getContext().getLangOptions().isSignedOverflowDefined())
1486      Address = Builder.CreateGEP(Base, Idx, "arrayidx");
1487    else
1488      Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1489  }
1490
1491  QualType T = E->getBase()->getType()->getPointeeType();
1492  assert(!T.isNull() &&
1493         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1494
1495  // Limit the alignment to that of the result type.
1496  if (ArrayAlignment) {
1497    unsigned Align = getContext().getTypeAlignInChars(T).getQuantity();
1498    ArrayAlignment = std::min(Align, ArrayAlignment);
1499  }
1500
1501  LValue LV = MakeAddrLValue(Address, T, ArrayAlignment);
1502  LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
1503
1504  if (getContext().getLangOptions().ObjC1 &&
1505      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1506    LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1507    setObjCGCLValueClass(getContext(), E, LV);
1508  }
1509  return LV;
1510}
1511
1512static
1513llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1514                                       llvm::SmallVector<unsigned, 4> &Elts) {
1515  llvm::SmallVector<llvm::Constant*, 4> CElts;
1516
1517  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1518  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1519    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1520
1521  return llvm::ConstantVector::get(CElts);
1522}
1523
1524LValue CodeGenFunction::
1525EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1526  // Emit the base vector as an l-value.
1527  LValue Base;
1528
1529  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1530  if (E->isArrow()) {
1531    // If it is a pointer to a vector, emit the address and form an lvalue with
1532    // it.
1533    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1534    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1535    Base = MakeAddrLValue(Ptr, PT->getPointeeType());
1536    Base.getQuals().removeObjCGCAttr();
1537  } else if (E->getBase()->isGLValue()) {
1538    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1539    // emit the base as an lvalue.
1540    assert(E->getBase()->getType()->isVectorType());
1541    Base = EmitLValue(E->getBase());
1542  } else {
1543    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1544    assert(E->getBase()->getType()->getAs<VectorType>() &&
1545           "Result must be a vector");
1546    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1547
1548    // Store the vector to memory (because LValue wants an address).
1549    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1550    Builder.CreateStore(Vec, VecMem);
1551    Base = MakeAddrLValue(VecMem, E->getBase()->getType());
1552  }
1553
1554  // Encode the element access list into a vector of unsigned indices.
1555  llvm::SmallVector<unsigned, 4> Indices;
1556  E->getEncodedElementAccess(Indices);
1557
1558  if (Base.isSimple()) {
1559    llvm::Constant *CV = GenerateConstantVector(getLLVMContext(), Indices);
1560    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1561                                    Base.getVRQualifiers());
1562  }
1563  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1564
1565  llvm::Constant *BaseElts = Base.getExtVectorElts();
1566  llvm::SmallVector<llvm::Constant *, 4> CElts;
1567
1568  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1569    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1570      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1571    else
1572      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1573  }
1574  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
1575  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1576                                  Base.getVRQualifiers());
1577}
1578
1579LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1580  bool isNonGC = false;
1581  Expr *BaseExpr = E->getBase();
1582  llvm::Value *BaseValue = NULL;
1583  Qualifiers BaseQuals;
1584
1585  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1586  if (E->isArrow()) {
1587    BaseValue = EmitScalarExpr(BaseExpr);
1588    const PointerType *PTy =
1589      BaseExpr->getType()->getAs<PointerType>();
1590    BaseQuals = PTy->getPointeeType().getQualifiers();
1591  } else {
1592    LValue BaseLV = EmitLValue(BaseExpr);
1593    if (BaseLV.isNonGC())
1594      isNonGC = true;
1595    // FIXME: this isn't right for bitfields.
1596    BaseValue = BaseLV.getAddress();
1597    QualType BaseTy = BaseExpr->getType();
1598    BaseQuals = BaseTy.getQualifiers();
1599  }
1600
1601  NamedDecl *ND = E->getMemberDecl();
1602  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1603    LValue LV = EmitLValueForField(BaseValue, Field,
1604                                   BaseQuals.getCVRQualifiers());
1605    LV.setNonGC(isNonGC);
1606    setObjCGCLValueClass(getContext(), E, LV);
1607    return LV;
1608  }
1609
1610  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1611    return EmitGlobalVarDeclLValue(*this, E, VD);
1612
1613  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1614    return EmitFunctionDeclLValue(*this, E, FD);
1615
1616  assert(false && "Unhandled member declaration!");
1617  return LValue();
1618}
1619
1620LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue,
1621                                              const FieldDecl *Field,
1622                                              unsigned CVRQualifiers) {
1623  const CGRecordLayout &RL =
1624    CGM.getTypes().getCGRecordLayout(Field->getParent());
1625  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1626  return LValue::MakeBitfield(BaseValue, Info,
1627                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1628}
1629
1630/// EmitLValueForAnonRecordField - Given that the field is a member of
1631/// an anonymous struct or union buried inside a record, and given
1632/// that the base value is a pointer to the enclosing record, derive
1633/// an lvalue for the ultimate field.
1634LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1635                                             const IndirectFieldDecl *Field,
1636                                                     unsigned CVRQualifiers) {
1637  IndirectFieldDecl::chain_iterator I = Field->chain_begin(),
1638    IEnd = Field->chain_end();
1639  while (true) {
1640    LValue LV = EmitLValueForField(BaseValue, cast<FieldDecl>(*I), CVRQualifiers);
1641    if (++I == IEnd) return LV;
1642
1643    assert(LV.isSimple());
1644    BaseValue = LV.getAddress();
1645    CVRQualifiers |= LV.getVRQualifiers();
1646  }
1647}
1648
1649LValue CodeGenFunction::EmitLValueForField(llvm::Value *baseAddr,
1650                                           const FieldDecl *field,
1651                                           unsigned cvr) {
1652  if (field->isBitField())
1653    return EmitLValueForBitfield(baseAddr, field, cvr);
1654
1655  const RecordDecl *rec = field->getParent();
1656  QualType type = field->getType();
1657
1658  bool mayAlias = rec->hasAttr<MayAliasAttr>();
1659
1660  llvm::Value *addr;
1661  if (rec->isUnion()) {
1662    // For unions, we just cast to the appropriate type.
1663    assert(!type->isReferenceType() && "union has reference member");
1664
1665    const llvm::Type *llvmType = CGM.getTypes().ConvertTypeForMem(type);
1666    unsigned AS =
1667      cast<llvm::PointerType>(baseAddr->getType())->getAddressSpace();
1668    addr = Builder.CreateBitCast(baseAddr, llvmType->getPointerTo(AS),
1669                                 field->getName());
1670  } else {
1671    // For structs, we GEP to the field that the record layout suggests.
1672    unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
1673    addr = Builder.CreateStructGEP(baseAddr, idx, field->getName());
1674
1675    // If this is a reference field, load the reference right now.
1676    if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
1677      llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
1678      if (cvr & Qualifiers::Volatile) load->setVolatile(true);
1679
1680      if (CGM.shouldUseTBAA()) {
1681        llvm::MDNode *tbaa;
1682        if (mayAlias)
1683          tbaa = CGM.getTBAAInfo(getContext().CharTy);
1684        else
1685          tbaa = CGM.getTBAAInfo(type);
1686        CGM.DecorateInstruction(load, tbaa);
1687      }
1688
1689      addr = load;
1690      mayAlias = false;
1691      type = refType->getPointeeType();
1692      cvr = 0; // qualifiers don't recursively apply to referencee
1693    }
1694  }
1695
1696  unsigned alignment = getContext().getDeclAlign(field).getQuantity();
1697  LValue LV = MakeAddrLValue(addr, type, alignment);
1698  LV.getQuals().addCVRQualifiers(cvr);
1699
1700  // __weak attribute on a field is ignored.
1701  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
1702    LV.getQuals().removeObjCGCAttr();
1703
1704  // Fields of may_alias structs act like 'char' for TBAA purposes.
1705  // FIXME: this should get propagated down through anonymous structs
1706  // and unions.
1707  if (mayAlias && LV.getTBAAInfo())
1708    LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
1709
1710  return LV;
1711}
1712
1713LValue
1714CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue,
1715                                                  const FieldDecl *Field,
1716                                                  unsigned CVRQualifiers) {
1717  QualType FieldType = Field->getType();
1718
1719  if (!FieldType->isReferenceType())
1720    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1721
1722  const CGRecordLayout &RL =
1723    CGM.getTypes().getCGRecordLayout(Field->getParent());
1724  unsigned idx = RL.getLLVMFieldNo(Field);
1725  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1726
1727  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1728
1729  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1730  return MakeAddrLValue(V, FieldType, Alignment);
1731}
1732
1733LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
1734  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1735  const Expr *InitExpr = E->getInitializer();
1736  LValue Result = MakeAddrLValue(DeclPtr, E->getType());
1737
1738  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false, /*Init*/ true);
1739
1740  return Result;
1741}
1742
1743LValue CodeGenFunction::
1744EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
1745  if (!expr->isGLValue()) {
1746    // ?: here should be an aggregate.
1747    assert((hasAggregateLLVMType(expr->getType()) &&
1748            !expr->getType()->isAnyComplexType()) &&
1749           "Unexpected conditional operator!");
1750    return EmitAggExprToLValue(expr);
1751  }
1752
1753  const Expr *condExpr = expr->getCond();
1754  bool CondExprBool;
1755  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
1756    const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
1757    if (!CondExprBool) std::swap(live, dead);
1758
1759    if (!ContainsLabel(dead))
1760      return EmitLValue(live);
1761  }
1762
1763  OpaqueValueMapping binding(*this, expr);
1764
1765  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
1766  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
1767  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
1768
1769  ConditionalEvaluation eval(*this);
1770  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock);
1771
1772  // Any temporaries created here are conditional.
1773  EmitBlock(lhsBlock);
1774  eval.begin(*this);
1775  LValue lhs = EmitLValue(expr->getTrueExpr());
1776  eval.end(*this);
1777
1778  if (!lhs.isSimple())
1779    return EmitUnsupportedLValue(expr, "conditional operator");
1780
1781  lhsBlock = Builder.GetInsertBlock();
1782  Builder.CreateBr(contBlock);
1783
1784  // Any temporaries created here are conditional.
1785  EmitBlock(rhsBlock);
1786  eval.begin(*this);
1787  LValue rhs = EmitLValue(expr->getFalseExpr());
1788  eval.end(*this);
1789  if (!rhs.isSimple())
1790    return EmitUnsupportedLValue(expr, "conditional operator");
1791  rhsBlock = Builder.GetInsertBlock();
1792
1793  EmitBlock(contBlock);
1794
1795  llvm::PHINode *phi = Builder.CreatePHI(lhs.getAddress()->getType(), 2,
1796                                         "cond-lvalue");
1797  phi->addIncoming(lhs.getAddress(), lhsBlock);
1798  phi->addIncoming(rhs.getAddress(), rhsBlock);
1799  return MakeAddrLValue(phi, expr->getType());
1800}
1801
1802/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1803/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1804/// otherwise if a cast is needed by the code generator in an lvalue context,
1805/// then it must mean that we need the address of an aggregate in order to
1806/// access one of its fields.  This can happen for all the reasons that casts
1807/// are permitted with aggregate result, including noop aggregate casts, and
1808/// cast from scalar to union.
1809LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1810  switch (E->getCastKind()) {
1811  case CK_ToVoid:
1812    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1813
1814  case CK_Dependent:
1815    llvm_unreachable("dependent cast kind in IR gen!");
1816
1817  case CK_GetObjCProperty: {
1818    LValue LV = EmitLValue(E->getSubExpr());
1819    assert(LV.isPropertyRef());
1820    RValue RV = EmitLoadOfPropertyRefLValue(LV);
1821
1822    // Property is an aggregate r-value.
1823    if (RV.isAggregate()) {
1824      return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
1825    }
1826
1827    // Implicit property returns an l-value.
1828    assert(RV.isScalar());
1829    return MakeAddrLValue(RV.getScalarVal(), E->getSubExpr()->getType());
1830  }
1831
1832  case CK_NoOp:
1833  case CK_LValueToRValue:
1834    if (!E->getSubExpr()->Classify(getContext()).isPRValue()
1835        || E->getType()->isRecordType())
1836      return EmitLValue(E->getSubExpr());
1837    // Fall through to synthesize a temporary.
1838
1839  case CK_BitCast:
1840  case CK_ArrayToPointerDecay:
1841  case CK_FunctionToPointerDecay:
1842  case CK_NullToMemberPointer:
1843  case CK_NullToPointer:
1844  case CK_IntegralToPointer:
1845  case CK_PointerToIntegral:
1846  case CK_PointerToBoolean:
1847  case CK_VectorSplat:
1848  case CK_IntegralCast:
1849  case CK_IntegralToBoolean:
1850  case CK_IntegralToFloating:
1851  case CK_FloatingToIntegral:
1852  case CK_FloatingToBoolean:
1853  case CK_FloatingCast:
1854  case CK_FloatingRealToComplex:
1855  case CK_FloatingComplexToReal:
1856  case CK_FloatingComplexToBoolean:
1857  case CK_FloatingComplexCast:
1858  case CK_FloatingComplexToIntegralComplex:
1859  case CK_IntegralRealToComplex:
1860  case CK_IntegralComplexToReal:
1861  case CK_IntegralComplexToBoolean:
1862  case CK_IntegralComplexCast:
1863  case CK_IntegralComplexToFloatingComplex:
1864  case CK_DerivedToBaseMemberPointer:
1865  case CK_BaseToDerivedMemberPointer:
1866  case CK_MemberPointerToBoolean:
1867  case CK_AnyPointerToBlockPointerCast: {
1868    // These casts only produce lvalues when we're binding a reference to a
1869    // temporary realized from a (converted) pure rvalue. Emit the expression
1870    // as a value, copy it into a temporary, and return an lvalue referring to
1871    // that temporary.
1872    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
1873    EmitAnyExprToMem(E, V, false, false);
1874    return MakeAddrLValue(V, E->getType());
1875  }
1876
1877  case CK_Dynamic: {
1878    LValue LV = EmitLValue(E->getSubExpr());
1879    llvm::Value *V = LV.getAddress();
1880    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1881    return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
1882  }
1883
1884  case CK_ConstructorConversion:
1885  case CK_UserDefinedConversion:
1886  case CK_AnyPointerToObjCPointerCast:
1887    return EmitLValue(E->getSubExpr());
1888
1889  case CK_UncheckedDerivedToBase:
1890  case CK_DerivedToBase: {
1891    const RecordType *DerivedClassTy =
1892      E->getSubExpr()->getType()->getAs<RecordType>();
1893    CXXRecordDecl *DerivedClassDecl =
1894      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1895
1896    LValue LV = EmitLValue(E->getSubExpr());
1897    llvm::Value *This = LV.getAddress();
1898
1899    // Perform the derived-to-base conversion
1900    llvm::Value *Base =
1901      GetAddressOfBaseClass(This, DerivedClassDecl,
1902                            E->path_begin(), E->path_end(),
1903                            /*NullCheckValue=*/false);
1904
1905    return MakeAddrLValue(Base, E->getType());
1906  }
1907  case CK_ToUnion:
1908    return EmitAggExprToLValue(E);
1909  case CK_BaseToDerived: {
1910    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1911    CXXRecordDecl *DerivedClassDecl =
1912      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1913
1914    LValue LV = EmitLValue(E->getSubExpr());
1915
1916    // Perform the base-to-derived conversion
1917    llvm::Value *Derived =
1918      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1919                               E->path_begin(), E->path_end(),
1920                               /*NullCheckValue=*/false);
1921
1922    return MakeAddrLValue(Derived, E->getType());
1923  }
1924  case CK_LValueBitCast: {
1925    // This must be a reinterpret_cast (or c-style equivalent).
1926    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1927
1928    LValue LV = EmitLValue(E->getSubExpr());
1929    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1930                                           ConvertType(CE->getTypeAsWritten()));
1931    return MakeAddrLValue(V, E->getType());
1932  }
1933  case CK_ObjCObjectLValueCast: {
1934    LValue LV = EmitLValue(E->getSubExpr());
1935    QualType ToType = getContext().getLValueReferenceType(E->getType());
1936    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1937                                           ConvertType(ToType));
1938    return MakeAddrLValue(V, E->getType());
1939  }
1940  }
1941
1942  llvm_unreachable("Unhandled lvalue cast kind?");
1943}
1944
1945LValue CodeGenFunction::EmitNullInitializationLValue(
1946                                              const CXXScalarValueInitExpr *E) {
1947  QualType Ty = E->getType();
1948  LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
1949  EmitNullInitialization(LV.getAddress(), Ty);
1950  return LV;
1951}
1952
1953LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
1954  assert(e->isGLValue() || e->getType()->isRecordType());
1955  return getOpaqueLValueMapping(e);
1956}
1957
1958//===--------------------------------------------------------------------===//
1959//                             Expression Emission
1960//===--------------------------------------------------------------------===//
1961
1962
1963RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
1964                                     ReturnValueSlot ReturnValue) {
1965  if (CGDebugInfo *DI = getDebugInfo()) {
1966    DI->setLocation(E->getLocStart());
1967    DI->UpdateLineDirectiveRegion(Builder);
1968    DI->EmitStopPoint(Builder);
1969  }
1970
1971  // Builtins never have block type.
1972  if (E->getCallee()->getType()->isBlockPointerType())
1973    return EmitBlockCallExpr(E, ReturnValue);
1974
1975  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1976    return EmitCXXMemberCallExpr(CE, ReturnValue);
1977
1978  const Decl *TargetDecl = 0;
1979  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1980    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1981      TargetDecl = DRE->getDecl();
1982      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1983        if (unsigned builtinID = FD->getBuiltinID())
1984          return EmitBuiltinExpr(FD, builtinID, E);
1985    }
1986  }
1987
1988  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1989    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1990      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
1991
1992  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1993    // C++ [expr.pseudo]p1:
1994    //   The result shall only be used as the operand for the function call
1995    //   operator (), and the result of such a call has type void. The only
1996    //   effect is the evaluation of the postfix-expression before the dot or
1997    //   arrow.
1998    EmitScalarExpr(E->getCallee());
1999    return RValue::get(0);
2000  }
2001
2002  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
2003  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
2004                  E->arg_begin(), E->arg_end(), TargetDecl);
2005}
2006
2007LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
2008  // Comma expressions just emit their LHS then their RHS as an l-value.
2009  if (E->getOpcode() == BO_Comma) {
2010    EmitIgnoredExpr(E->getLHS());
2011    EnsureInsertPoint();
2012    return EmitLValue(E->getRHS());
2013  }
2014
2015  if (E->getOpcode() == BO_PtrMemD ||
2016      E->getOpcode() == BO_PtrMemI)
2017    return EmitPointerToDataMemberBinaryExpr(E);
2018
2019  assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
2020
2021  if (!hasAggregateLLVMType(E->getType())) {
2022    // __block variables need the RHS evaluated first.
2023    RValue RV = EmitAnyExpr(E->getRHS());
2024    LValue LV = EmitLValue(E->getLHS());
2025    EmitStoreThroughLValue(RV, LV, E->getType());
2026    return LV;
2027  }
2028
2029  if (E->getType()->isAnyComplexType())
2030    return EmitComplexAssignmentLValue(E);
2031
2032  return EmitAggExprToLValue(E);
2033}
2034
2035LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
2036  RValue RV = EmitCallExpr(E);
2037
2038  if (!RV.isScalar())
2039    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2040
2041  assert(E->getCallReturnType()->isReferenceType() &&
2042         "Can't have a scalar return unless the return type is a "
2043         "reference type!");
2044
2045  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2046}
2047
2048LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
2049  // FIXME: This shouldn't require another copy.
2050  return EmitAggExprToLValue(E);
2051}
2052
2053LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
2054  assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
2055         && "binding l-value to type which needs a temporary");
2056  AggValueSlot Slot = CreateAggTemp(E->getType(), "tmp");
2057  EmitCXXConstructExpr(E, Slot);
2058  return MakeAddrLValue(Slot.getAddr(), E->getType());
2059}
2060
2061LValue
2062CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
2063  return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
2064}
2065
2066LValue
2067CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
2068  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
2069  Slot.setLifetimeExternallyManaged();
2070  EmitAggExpr(E->getSubExpr(), Slot);
2071  EmitCXXTemporary(E->getTemporary(), Slot.getAddr());
2072  return MakeAddrLValue(Slot.getAddr(), E->getType());
2073}
2074
2075LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
2076  RValue RV = EmitObjCMessageExpr(E);
2077
2078  if (!RV.isScalar())
2079    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2080
2081  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2082         "Can't have a scalar return unless the return type is a "
2083         "reference type!");
2084
2085  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2086}
2087
2088LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2089  llvm::Value *V =
2090    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2091  return MakeAddrLValue(V, E->getType());
2092}
2093
2094llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2095                                             const ObjCIvarDecl *Ivar) {
2096  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2097}
2098
2099LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2100                                          llvm::Value *BaseValue,
2101                                          const ObjCIvarDecl *Ivar,
2102                                          unsigned CVRQualifiers) {
2103  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2104                                                   Ivar, CVRQualifiers);
2105}
2106
2107LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2108  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2109  llvm::Value *BaseValue = 0;
2110  const Expr *BaseExpr = E->getBase();
2111  Qualifiers BaseQuals;
2112  QualType ObjectTy;
2113  if (E->isArrow()) {
2114    BaseValue = EmitScalarExpr(BaseExpr);
2115    ObjectTy = BaseExpr->getType()->getPointeeType();
2116    BaseQuals = ObjectTy.getQualifiers();
2117  } else {
2118    LValue BaseLV = EmitLValue(BaseExpr);
2119    // FIXME: this isn't right for bitfields.
2120    BaseValue = BaseLV.getAddress();
2121    ObjectTy = BaseExpr->getType();
2122    BaseQuals = ObjectTy.getQualifiers();
2123  }
2124
2125  LValue LV =
2126    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2127                      BaseQuals.getCVRQualifiers());
2128  setObjCGCLValueClass(getContext(), E, LV);
2129  return LV;
2130}
2131
2132LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2133  // Can only get l-value for message expression returning aggregate type
2134  RValue RV = EmitAnyExprToTemp(E);
2135  return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2136}
2137
2138RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2139                                 ReturnValueSlot ReturnValue,
2140                                 CallExpr::const_arg_iterator ArgBeg,
2141                                 CallExpr::const_arg_iterator ArgEnd,
2142                                 const Decl *TargetDecl) {
2143  // Get the actual function type. The callee type will always be a pointer to
2144  // function type or a block pointer type.
2145  assert(CalleeType->isFunctionPointerType() &&
2146         "Call must have function pointer type!");
2147
2148  CalleeType = getContext().getCanonicalType(CalleeType);
2149
2150  const FunctionType *FnType
2151    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2152
2153  CallArgList Args;
2154  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2155
2156  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2157                  Callee, ReturnValue, Args, TargetDecl);
2158}
2159
2160LValue CodeGenFunction::
2161EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2162  llvm::Value *BaseV;
2163  if (E->getOpcode() == BO_PtrMemI)
2164    BaseV = EmitScalarExpr(E->getLHS());
2165  else
2166    BaseV = EmitLValue(E->getLHS()).getAddress();
2167
2168  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2169
2170  const MemberPointerType *MPT
2171    = E->getRHS()->getType()->getAs<MemberPointerType>();
2172
2173  llvm::Value *AddV =
2174    CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT);
2175
2176  return MakeAddrLValue(AddV, MPT->getPointeeType());
2177}
2178