CGExpr.cpp revision 7eb0a9eb0cde8444b97f9c5b713d9be7a6f1e607 
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
32/// CreateTempAlloca - This creates a alloca and inserts it into the entry
33/// block.
34llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
35                                                    const llvm::Twine &Name) {
36  if (!Builder.isNamePreserving())
37    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
38  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
39}
40
41void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
42                                     llvm::Value *Init) {
43  llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
44  llvm::BasicBlock *Block = AllocaInsertPt->getParent();
45  Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
46}
47
48llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
49                                                const llvm::Twine &Name) {
50  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
51  // FIXME: Should we prefer the preferred type alignment here?
52  CharUnits Align = getContext().getTypeAlignInChars(Ty);
53  Alloc->setAlignment(Align.getQuantity());
54  return Alloc;
55}
56
57llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
58                                                 const llvm::Twine &Name) {
59  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
60  // FIXME: Should we prefer the preferred type alignment here?
61  CharUnits Align = getContext().getTypeAlignInChars(Ty);
62  Alloc->setAlignment(Align.getQuantity());
63  return Alloc;
64}
65
66/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
67/// expression and compare the result against zero, returning an Int1Ty value.
68llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
69  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
70    llvm::Value *MemPtr = EmitScalarExpr(E);
71    return CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT);
72  }
73
74  QualType BoolTy = getContext().BoolTy;
75  if (!E->getType()->isAnyComplexType())
76    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
77
78  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
79}
80
81/// EmitAnyExpr - Emit code to compute the specified expression which
82/// can have any type.  The result is returned as an RValue struct.
83/// If this is an aggregate expression, AggSlot indicates where the
84/// result should be returned.
85RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot,
86                                    bool IgnoreResult) {
87  if (!hasAggregateLLVMType(E->getType()))
88    return RValue::get(EmitScalarExpr(E, IgnoreResult));
89  else if (E->getType()->isAnyComplexType())
90    return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult));
91
92  EmitAggExpr(E, AggSlot, IgnoreResult);
93  return AggSlot.asRValue();
94}
95
96/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
97/// always be accessible even if no aggregate location is provided.
98RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
99  AggValueSlot AggSlot = AggValueSlot::ignored();
100
101  if (hasAggregateLLVMType(E->getType()) &&
102      !E->getType()->isAnyComplexType())
103    AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
104  return EmitAnyExpr(E, AggSlot);
105}
106
107/// EmitAnyExprToMem - Evaluate an expression into a given memory
108/// location.
109void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
110                                       llvm::Value *Location,
111                                       bool IsLocationVolatile,
112                                       bool IsInit) {
113  if (E->getType()->isComplexType())
114    EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
115  else if (hasAggregateLLVMType(E->getType()))
116    EmitAggExpr(E, AggValueSlot::forAddr(Location, IsLocationVolatile, IsInit));
117  else {
118    RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
119    LValue LV = MakeAddrLValue(Location, E->getType());
120    EmitStoreThroughLValue(RV, LV, E->getType());
121  }
122}
123
124/// \brief An adjustment to be made to the temporary created when emitting a
125/// reference binding, which accesses a particular subobject of that temporary.
126struct SubobjectAdjustment {
127  enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
128
129  union {
130    struct {
131      const CastExpr *BasePath;
132      const CXXRecordDecl *DerivedClass;
133    } DerivedToBase;
134
135    FieldDecl *Field;
136  };
137
138  SubobjectAdjustment(const CastExpr *BasePath,
139                      const CXXRecordDecl *DerivedClass)
140    : Kind(DerivedToBaseAdjustment)
141  {
142    DerivedToBase.BasePath = BasePath;
143    DerivedToBase.DerivedClass = DerivedClass;
144  }
145
146  SubobjectAdjustment(FieldDecl *Field)
147    : Kind(FieldAdjustment)
148  {
149    this->Field = Field;
150  }
151};
152
153static llvm::Value *
154CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
155                         const NamedDecl *InitializedDecl) {
156  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
157    if (VD->hasGlobalStorage()) {
158      llvm::SmallString<256> Name;
159      CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Name);
160
161      const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
162
163      // Create the reference temporary.
164      llvm::GlobalValue *RefTemp =
165        new llvm::GlobalVariable(CGF.CGM.getModule(),
166                                 RefTempTy, /*isConstant=*/false,
167                                 llvm::GlobalValue::InternalLinkage,
168                                 llvm::Constant::getNullValue(RefTempTy),
169                                 Name.str());
170      return RefTemp;
171    }
172  }
173
174  return CGF.CreateMemTemp(Type, "ref.tmp");
175}
176
177static llvm::Value *
178EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
179                            llvm::Value *&ReferenceTemporary,
180                            const CXXDestructorDecl *&ReferenceTemporaryDtor,
181                            const NamedDecl *InitializedDecl) {
182  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
183    E = DAE->getExpr();
184
185  if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
186    CodeGenFunction::RunCleanupsScope Scope(CGF);
187
188    return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
189                                       ReferenceTemporary,
190                                       ReferenceTemporaryDtor,
191                                       InitializedDecl);
192  }
193
194  RValue RV;
195  if (E->isLValue()) {
196    // Emit the expression as an lvalue.
197    LValue LV = CGF.EmitLValue(E);
198    if (LV.isPropertyRef() || LV.isKVCRef()) {
199      QualType QT = E->getType();
200      RValue RV =
201        LV.isPropertyRef() ? CGF.EmitLoadOfPropertyRefLValue(LV, QT)
202                           : CGF.EmitLoadOfKVCRefLValue(LV, QT);
203      assert(RV.isScalar() && "EmitExprForReferenceBinding");
204      return RV.getScalarVal();
205    }
206
207    if (LV.isSimple())
208      return LV.getAddress();
209
210    // We have to load the lvalue.
211    RV = CGF.EmitLoadOfLValue(LV, E->getType());
212  } else {
213    QualType ResultTy = E->getType();
214
215    llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
216    while (true) {
217      if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
218        E = PE->getSubExpr();
219        continue;
220      }
221
222      if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
223        if ((CE->getCastKind() == CK_DerivedToBase ||
224             CE->getCastKind() == CK_UncheckedDerivedToBase) &&
225            E->getType()->isRecordType()) {
226          E = CE->getSubExpr();
227          CXXRecordDecl *Derived
228            = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
229          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
230          continue;
231        }
232
233        if (CE->getCastKind() == CK_NoOp) {
234          E = CE->getSubExpr();
235          continue;
236        }
237      } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
238        if (!ME->isArrow() && ME->getBase()->isRValue()) {
239          assert(ME->getBase()->getType()->isRecordType());
240          if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
241            E = ME->getBase();
242            Adjustments.push_back(SubobjectAdjustment(Field));
243            continue;
244          }
245        }
246      }
247
248      // Nothing changed.
249      break;
250    }
251
252    // Create a reference temporary if necessary.
253    AggValueSlot AggSlot = AggValueSlot::ignored();
254    if (CGF.hasAggregateLLVMType(E->getType()) &&
255        !E->getType()->isAnyComplexType()) {
256      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
257                                                    InitializedDecl);
258      AggSlot = AggValueSlot::forAddr(ReferenceTemporary, false,
259                                      InitializedDecl != 0);
260    }
261
262    RV = CGF.EmitAnyExpr(E, AggSlot);
263
264    if (InitializedDecl) {
265      // Get the destructor for the reference temporary.
266      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
267        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
268        if (!ClassDecl->hasTrivialDestructor())
269          ReferenceTemporaryDtor = ClassDecl->getDestructor();
270      }
271    }
272
273    // Check if need to perform derived-to-base casts and/or field accesses, to
274    // get from the temporary object we created (and, potentially, for which we
275    // extended the lifetime) to the subobject we're binding the reference to.
276    if (!Adjustments.empty()) {
277      llvm::Value *Object = RV.getAggregateAddr();
278      for (unsigned I = Adjustments.size(); I != 0; --I) {
279        SubobjectAdjustment &Adjustment = Adjustments[I-1];
280        switch (Adjustment.Kind) {
281        case SubobjectAdjustment::DerivedToBaseAdjustment:
282          Object =
283              CGF.GetAddressOfBaseClass(Object,
284                                        Adjustment.DerivedToBase.DerivedClass,
285                              Adjustment.DerivedToBase.BasePath->path_begin(),
286                              Adjustment.DerivedToBase.BasePath->path_end(),
287                                        /*NullCheckValue=*/false);
288          break;
289
290        case SubobjectAdjustment::FieldAdjustment: {
291          LValue LV =
292            CGF.EmitLValueForField(Object, Adjustment.Field, 0);
293          if (LV.isSimple()) {
294            Object = LV.getAddress();
295            break;
296          }
297
298          // For non-simple lvalues, we actually have to create a copy of
299          // the object we're binding to.
300          QualType T = Adjustment.Field->getType().getNonReferenceType()
301                                                  .getUnqualifiedType();
302          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
303          LValue TempLV = CGF.MakeAddrLValue(Object,
304                                             Adjustment.Field->getType());
305          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV, T), TempLV, T);
306          break;
307        }
308
309        }
310      }
311
312      const llvm::Type *ResultPtrTy = CGF.ConvertType(ResultTy)->getPointerTo();
313      return CGF.Builder.CreateBitCast(Object, ResultPtrTy, "temp");
314    }
315  }
316
317  if (RV.isAggregate())
318    return RV.getAggregateAddr();
319
320  // Create a temporary variable that we can bind the reference to.
321  ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
322                                                InitializedDecl);
323
324
325  unsigned Alignment =
326    CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
327  if (RV.isScalar())
328    CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
329                          /*Volatile=*/false, Alignment, E->getType());
330  else
331    CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
332                           /*Volatile=*/false);
333  return ReferenceTemporary;
334}
335
336RValue
337CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E,
338                                            const NamedDecl *InitializedDecl) {
339  llvm::Value *ReferenceTemporary = 0;
340  const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
341  llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
342                                                   ReferenceTemporaryDtor,
343                                                   InitializedDecl);
344  if (!ReferenceTemporaryDtor)
345    return RValue::get(Value);
346
347  // Make sure to call the destructor for the reference temporary.
348  if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
349    if (VD->hasGlobalStorage()) {
350      llvm::Constant *DtorFn =
351        CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
352      CGF.EmitCXXGlobalDtorRegistration(DtorFn,
353                                      cast<llvm::Constant>(ReferenceTemporary));
354
355      return RValue::get(Value);
356    }
357  }
358
359  PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
360
361  return RValue::get(Value);
362}
363
364
365/// getAccessedFieldNo - Given an encoded value and a result number, return the
366/// input field number being accessed.
367unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
368                                             const llvm::Constant *Elts) {
369  if (isa<llvm::ConstantAggregateZero>(Elts))
370    return 0;
371
372  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
373}
374
375void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
376  if (!CatchUndefined)
377    return;
378
379  Address = Builder.CreateBitCast(Address, PtrToInt8Ty);
380
381  const llvm::Type *IntPtrT = IntPtrTy;
382  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
383  const llvm::IntegerType *Int1Ty = llvm::Type::getInt1Ty(VMContext);
384
385  // In time, people may want to control this and use a 1 here.
386  llvm::Value *Arg = llvm::ConstantInt::get(Int1Ty, 0);
387  llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
388  llvm::BasicBlock *Cont = createBasicBlock();
389  llvm::BasicBlock *Check = createBasicBlock();
390  llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
391  Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
392
393  EmitBlock(Check);
394  Builder.CreateCondBr(Builder.CreateICmpUGE(C,
395                                        llvm::ConstantInt::get(IntPtrTy, Size)),
396                       Cont, getTrapBB());
397  EmitBlock(Cont);
398}
399
400
401CodeGenFunction::ComplexPairTy CodeGenFunction::
402EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
403                         bool isInc, bool isPre) {
404  ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
405                                            LV.isVolatileQualified());
406
407  llvm::Value *NextVal;
408  if (isa<llvm::IntegerType>(InVal.first->getType())) {
409    uint64_t AmountVal = isInc ? 1 : -1;
410    NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
411
412    // Add the inc/dec to the real part.
413    NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
414  } else {
415    QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
416    llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
417    if (!isInc)
418      FVal.changeSign();
419    NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
420
421    // Add the inc/dec to the real part.
422    NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
423  }
424
425  ComplexPairTy IncVal(NextVal, InVal.second);
426
427  // Store the updated result through the lvalue.
428  StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
429
430  // If this is a postinc, return the value read from memory, otherwise use the
431  // updated value.
432  return isPre ? IncVal : InVal;
433}
434
435
436//===----------------------------------------------------------------------===//
437//                         LValue Expression Emission
438//===----------------------------------------------------------------------===//
439
440RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
441  if (Ty->isVoidType())
442    return RValue::get(0);
443
444  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
445    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
446    llvm::Value *U = llvm::UndefValue::get(EltTy);
447    return RValue::getComplex(std::make_pair(U, U));
448  }
449
450  // If this is a use of an undefined aggregate type, the aggregate must have an
451  // identifiable address.  Just because the contents of the value are undefined
452  // doesn't mean that the address can't be taken and compared.
453  if (hasAggregateLLVMType(Ty)) {
454    llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
455    return RValue::getAggregate(DestPtr);
456  }
457
458  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
459}
460
461RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
462                                              const char *Name) {
463  ErrorUnsupported(E, Name);
464  return GetUndefRValue(E->getType());
465}
466
467LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
468                                              const char *Name) {
469  ErrorUnsupported(E, Name);
470  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
471  return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType());
472}
473
474LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
475  LValue LV = EmitLValue(E);
476  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
477    EmitCheck(LV.getAddress(), getContext().getTypeSize(E->getType()) / 8);
478  return LV;
479}
480
481/// EmitLValue - Emit code to compute a designator that specifies the location
482/// of the expression.
483///
484/// This can return one of two things: a simple address or a bitfield reference.
485/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
486/// an LLVM pointer type.
487///
488/// If this returns a bitfield reference, nothing about the pointee type of the
489/// LLVM value is known: For example, it may not be a pointer to an integer.
490///
491/// If this returns a normal address, and if the lvalue's C type is fixed size,
492/// this method guarantees that the returned pointer type will point to an LLVM
493/// type of the same size of the lvalue's type.  If the lvalue has a variable
494/// length type, this is not possible.
495///
496LValue CodeGenFunction::EmitLValue(const Expr *E) {
497  llvm::DenseMap<const Expr *, LValue>::iterator I =
498                                      CGF.ConditionalSaveLValueExprs.find(E);
499  if (I != CGF.ConditionalSaveLValueExprs.end())
500    return I->second;
501
502  switch (E->getStmtClass()) {
503  default: return EmitUnsupportedLValue(E, "l-value expression");
504
505  case Expr::ObjCSelectorExprClass:
506  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
507  case Expr::ObjCIsaExprClass:
508    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
509  case Expr::BinaryOperatorClass:
510    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
511  case Expr::CompoundAssignOperatorClass:
512    return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
513  case Expr::CallExprClass:
514  case Expr::CXXMemberCallExprClass:
515  case Expr::CXXOperatorCallExprClass:
516    return EmitCallExprLValue(cast<CallExpr>(E));
517  case Expr::VAArgExprClass:
518    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
519  case Expr::DeclRefExprClass:
520    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
521  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
522  case Expr::PredefinedExprClass:
523    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
524  case Expr::StringLiteralClass:
525    return EmitStringLiteralLValue(cast<StringLiteral>(E));
526  case Expr::ObjCEncodeExprClass:
527    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
528
529  case Expr::BlockDeclRefExprClass:
530    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
531
532  case Expr::CXXTemporaryObjectExprClass:
533  case Expr::CXXConstructExprClass:
534    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
535  case Expr::CXXBindTemporaryExprClass:
536    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
537  case Expr::CXXExprWithTemporariesClass:
538    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
539  case Expr::CXXScalarValueInitExprClass:
540    return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
541  case Expr::CXXDefaultArgExprClass:
542    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
543  case Expr::CXXTypeidExprClass:
544    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
545
546  case Expr::ObjCMessageExprClass:
547    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
548  case Expr::ObjCIvarRefExprClass:
549    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
550  case Expr::ObjCPropertyRefExprClass:
551    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
552  case Expr::ObjCImplicitSetterGetterRefExprClass:
553    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
554  case Expr::StmtExprClass:
555    return EmitStmtExprLValue(cast<StmtExpr>(E));
556  case Expr::UnaryOperatorClass:
557    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
558  case Expr::ArraySubscriptExprClass:
559    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
560  case Expr::ExtVectorElementExprClass:
561    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
562  case Expr::MemberExprClass:
563    return EmitMemberExpr(cast<MemberExpr>(E));
564  case Expr::CompoundLiteralExprClass:
565    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
566  case Expr::ConditionalOperatorClass:
567    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
568  case Expr::ChooseExprClass:
569    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
570  case Expr::ImplicitCastExprClass:
571  case Expr::CStyleCastExprClass:
572  case Expr::CXXFunctionalCastExprClass:
573  case Expr::CXXStaticCastExprClass:
574  case Expr::CXXDynamicCastExprClass:
575  case Expr::CXXReinterpretCastExprClass:
576  case Expr::CXXConstCastExprClass:
577    return EmitCastLValue(cast<CastExpr>(E));
578  }
579}
580
581llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
582                                              unsigned Alignment, QualType Ty,
583                                              llvm::MDNode *TBAAInfo) {
584  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
585  if (Volatile)
586    Load->setVolatile(true);
587  if (Alignment)
588    Load->setAlignment(Alignment);
589  if (TBAAInfo)
590    CGM.DecorateInstruction(Load, TBAAInfo);
591
592  return EmitFromMemory(Load, Ty);
593}
594
595static bool isBooleanUnderlyingType(QualType Ty) {
596  if (const EnumType *ET = dyn_cast<EnumType>(Ty))
597    return ET->getDecl()->getIntegerType()->isBooleanType();
598  return false;
599}
600
601llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
602  // Bool has a different representation in memory than in registers.
603  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
604    // This should really always be an i1, but sometimes it's already
605    // an i8, and it's awkward to track those cases down.
606    if (Value->getType()->isIntegerTy(1))
607      return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool");
608    assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8");
609  }
610
611  return Value;
612}
613
614llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
615  // Bool has a different representation in memory than in registers.
616  if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
617    assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8");
618    return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
619  }
620
621  return Value;
622}
623
624void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
625                                        bool Volatile, unsigned Alignment,
626                                        QualType Ty,
627                                        llvm::MDNode *TBAAInfo) {
628  Value = EmitToMemory(Value, Ty);
629  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
630  if (Alignment)
631    Store->setAlignment(Alignment);
632  if (TBAAInfo)
633    CGM.DecorateInstruction(Store, TBAAInfo);
634}
635
636/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
637/// method emits the address of the lvalue, then loads the result as an rvalue,
638/// returning the rvalue.
639RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
640  if (LV.isObjCWeak()) {
641    // load of a __weak object.
642    llvm::Value *AddrWeakObj = LV.getAddress();
643    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
644                                                             AddrWeakObj));
645  }
646
647  if (LV.isSimple()) {
648    llvm::Value *Ptr = LV.getAddress();
649
650    // Functions are l-values that don't require loading.
651    if (ExprType->isFunctionType())
652      return RValue::get(Ptr);
653
654    // Everything needs a load.
655    return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
656                                        LV.getAlignment(), ExprType,
657                                        LV.getTBAAInfo()));
658
659  }
660
661  if (LV.isVectorElt()) {
662    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
663                                          LV.isVolatileQualified(), "tmp");
664    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
665                                                    "vecext"));
666  }
667
668  // If this is a reference to a subset of the elements of a vector, either
669  // shuffle the input or extract/insert them as appropriate.
670  if (LV.isExtVectorElt())
671    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
672
673  if (LV.isBitField())
674    return EmitLoadOfBitfieldLValue(LV, ExprType);
675
676  if (LV.isPropertyRef())
677    return EmitLoadOfPropertyRefLValue(LV, ExprType);
678
679  assert(LV.isKVCRef() && "Unknown LValue type!");
680  return EmitLoadOfKVCRefLValue(LV, ExprType);
681}
682
683RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
684                                                 QualType ExprType) {
685  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
686
687  // Get the output type.
688  const llvm::Type *ResLTy = ConvertType(ExprType);
689  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
690
691  // Compute the result as an OR of all of the individual component accesses.
692  llvm::Value *Res = 0;
693  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
694    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
695
696    // Get the field pointer.
697    llvm::Value *Ptr = LV.getBitFieldBaseAddr();
698
699    // Only offset by the field index if used, so that incoming values are not
700    // required to be structures.
701    if (AI.FieldIndex)
702      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
703
704    // Offset by the byte offset, if used.
705    if (AI.FieldByteOffset) {
706      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
707      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
708      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
709    }
710
711    // Cast to the access type.
712    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
713                                                    ExprType.getAddressSpace());
714    Ptr = Builder.CreateBitCast(Ptr, PTy);
715
716    // Perform the load.
717    llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
718    if (AI.AccessAlignment)
719      Load->setAlignment(AI.AccessAlignment);
720
721    // Shift out unused low bits and mask out unused high bits.
722    llvm::Value *Val = Load;
723    if (AI.FieldBitStart)
724      Val = Builder.CreateLShr(Load, AI.FieldBitStart);
725    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
726                                                            AI.TargetBitWidth),
727                            "bf.clear");
728
729    // Extend or truncate to the target size.
730    if (AI.AccessWidth < ResSizeInBits)
731      Val = Builder.CreateZExt(Val, ResLTy);
732    else if (AI.AccessWidth > ResSizeInBits)
733      Val = Builder.CreateTrunc(Val, ResLTy);
734
735    // Shift into place, and OR into the result.
736    if (AI.TargetBitOffset)
737      Val = Builder.CreateShl(Val, AI.TargetBitOffset);
738    Res = Res ? Builder.CreateOr(Res, Val) : Val;
739  }
740
741  // If the bit-field is signed, perform the sign-extension.
742  //
743  // FIXME: This can easily be folded into the load of the high bits, which
744  // could also eliminate the mask of high bits in some situations.
745  if (Info.isSigned()) {
746    unsigned ExtraBits = ResSizeInBits - Info.getSize();
747    if (ExtraBits)
748      Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
749                               ExtraBits, "bf.val.sext");
750  }
751
752  return RValue::get(Res);
753}
754
755RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
756                                                    QualType ExprType) {
757  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
758}
759
760RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
761                                               QualType ExprType) {
762  return EmitObjCPropertyGet(LV.getKVCRefExpr());
763}
764
765// If this is a reference to a subset of the elements of a vector, create an
766// appropriate shufflevector.
767RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
768                                                         QualType ExprType) {
769  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
770                                        LV.isVolatileQualified(), "tmp");
771
772  const llvm::Constant *Elts = LV.getExtVectorElts();
773
774  // If the result of the expression is a non-vector type, we must be extracting
775  // a single element.  Just codegen as an extractelement.
776  const VectorType *ExprVT = ExprType->getAs<VectorType>();
777  if (!ExprVT) {
778    unsigned InIdx = getAccessedFieldNo(0, Elts);
779    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
780    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
781  }
782
783  // Always use shuffle vector to try to retain the original program structure
784  unsigned NumResultElts = ExprVT->getNumElements();
785
786  llvm::SmallVector<llvm::Constant*, 4> Mask;
787  for (unsigned i = 0; i != NumResultElts; ++i) {
788    unsigned InIdx = getAccessedFieldNo(i, Elts);
789    Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx));
790  }
791
792  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
793  Vec = Builder.CreateShuffleVector(Vec,
794                                    llvm::UndefValue::get(Vec->getType()),
795                                    MaskV, "tmp");
796  return RValue::get(Vec);
797}
798
799
800
801/// EmitStoreThroughLValue - Store the specified rvalue into the specified
802/// lvalue, where both are guaranteed to the have the same type, and that type
803/// is 'Ty'.
804void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
805                                             QualType Ty) {
806  if (!Dst.isSimple()) {
807    if (Dst.isVectorElt()) {
808      // Read/modify/write the vector, inserting the new element.
809      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
810                                            Dst.isVolatileQualified(), "tmp");
811      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
812                                        Dst.getVectorIdx(), "vecins");
813      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
814      return;
815    }
816
817    // If this is an update of extended vector elements, insert them as
818    // appropriate.
819    if (Dst.isExtVectorElt())
820      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
821
822    if (Dst.isBitField())
823      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
824
825    if (Dst.isPropertyRef())
826      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
827
828    assert(Dst.isKVCRef() && "Unknown LValue type");
829    return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
830  }
831
832  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
833    // load of a __weak object.
834    llvm::Value *LvalueDst = Dst.getAddress();
835    llvm::Value *src = Src.getScalarVal();
836     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
837    return;
838  }
839
840  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
841    // load of a __strong object.
842    llvm::Value *LvalueDst = Dst.getAddress();
843    llvm::Value *src = Src.getScalarVal();
844    if (Dst.isObjCIvar()) {
845      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
846      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
847      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
848      llvm::Value *dst = RHS;
849      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
850      llvm::Value *LHS =
851        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
852      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
853      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
854                                              BytesBetween);
855    } else if (Dst.isGlobalObjCRef()) {
856      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
857                                                Dst.isThreadLocalRef());
858    }
859    else
860      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
861    return;
862  }
863
864  assert(Src.isScalar() && "Can't emit an agg store with this method");
865  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
866                    Dst.isVolatileQualified(), Dst.getAlignment(), Ty,
867                    Dst.getTBAAInfo());
868}
869
870void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
871                                                     QualType Ty,
872                                                     llvm::Value **Result) {
873  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
874
875  // Get the output type.
876  const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
877  unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
878
879  // Get the source value, truncated to the width of the bit-field.
880  llvm::Value *SrcVal = Src.getScalarVal();
881
882  if (Ty->isBooleanType())
883    SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
884
885  SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
886                                                                Info.getSize()),
887                             "bf.value");
888
889  // Return the new value of the bit-field, if requested.
890  if (Result) {
891    // Cast back to the proper type for result.
892    const llvm::Type *SrcTy = Src.getScalarVal()->getType();
893    llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
894                                                   "bf.reload.val");
895
896    // Sign extend if necessary.
897    if (Info.isSigned()) {
898      unsigned ExtraBits = ResSizeInBits - Info.getSize();
899      if (ExtraBits)
900        ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
901                                       ExtraBits, "bf.reload.sext");
902    }
903
904    *Result = ReloadVal;
905  }
906
907  // Iterate over the components, writing each piece to memory.
908  for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
909    const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
910
911    // Get the field pointer.
912    llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
913
914    // Only offset by the field index if used, so that incoming values are not
915    // required to be structures.
916    if (AI.FieldIndex)
917      Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
918
919    // Offset by the byte offset, if used.
920    if (AI.FieldByteOffset) {
921      const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
922      Ptr = Builder.CreateBitCast(Ptr, i8PTy);
923      Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
924    }
925
926    // Cast to the access type.
927    const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
928                                                     Ty.getAddressSpace());
929    Ptr = Builder.CreateBitCast(Ptr, PTy);
930
931    // Extract the piece of the bit-field value to write in this access, limited
932    // to the values that are part of this access.
933    llvm::Value *Val = SrcVal;
934    if (AI.TargetBitOffset)
935      Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
936    Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
937                                                            AI.TargetBitWidth));
938
939    // Extend or truncate to the access size.
940    const llvm::Type *AccessLTy =
941      llvm::Type::getIntNTy(VMContext, AI.AccessWidth);
942    if (ResSizeInBits < AI.AccessWidth)
943      Val = Builder.CreateZExt(Val, AccessLTy);
944    else if (ResSizeInBits > AI.AccessWidth)
945      Val = Builder.CreateTrunc(Val, AccessLTy);
946
947    // Shift into the position in memory.
948    if (AI.FieldBitStart)
949      Val = Builder.CreateShl(Val, AI.FieldBitStart);
950
951    // If necessary, load and OR in bits that are outside of the bit-field.
952    if (AI.TargetBitWidth != AI.AccessWidth) {
953      llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
954      if (AI.AccessAlignment)
955        Load->setAlignment(AI.AccessAlignment);
956
957      // Compute the mask for zeroing the bits that are part of the bit-field.
958      llvm::APInt InvMask =
959        ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
960                                 AI.FieldBitStart + AI.TargetBitWidth);
961
962      // Apply the mask and OR in to the value to write.
963      Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
964    }
965
966    // Write the value.
967    llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
968                                                 Dst.isVolatileQualified());
969    if (AI.AccessAlignment)
970      Store->setAlignment(AI.AccessAlignment);
971  }
972}
973
974void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
975                                                        LValue Dst,
976                                                        QualType Ty) {
977  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
978}
979
980void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
981                                                   LValue Dst,
982                                                   QualType Ty) {
983  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
984}
985
986void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
987                                                               LValue Dst,
988                                                               QualType Ty) {
989  // This access turns into a read/modify/write of the vector.  Load the input
990  // value now.
991  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
992                                        Dst.isVolatileQualified(), "tmp");
993  const llvm::Constant *Elts = Dst.getExtVectorElts();
994
995  llvm::Value *SrcVal = Src.getScalarVal();
996
997  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
998    unsigned NumSrcElts = VTy->getNumElements();
999    unsigned NumDstElts =
1000       cast<llvm::VectorType>(Vec->getType())->getNumElements();
1001    if (NumDstElts == NumSrcElts) {
1002      // Use shuffle vector is the src and destination are the same number of
1003      // elements and restore the vector mask since it is on the side it will be
1004      // stored.
1005      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1006      for (unsigned i = 0; i != NumSrcElts; ++i) {
1007        unsigned InIdx = getAccessedFieldNo(i, Elts);
1008        Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
1009      }
1010
1011      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
1012      Vec = Builder.CreateShuffleVector(SrcVal,
1013                                        llvm::UndefValue::get(Vec->getType()),
1014                                        MaskV, "tmp");
1015    } else if (NumDstElts > NumSrcElts) {
1016      // Extended the source vector to the same length and then shuffle it
1017      // into the destination.
1018      // FIXME: since we're shuffling with undef, can we just use the indices
1019      //        into that?  This could be simpler.
1020      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
1021      unsigned i;
1022      for (i = 0; i != NumSrcElts; ++i)
1023        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
1024      for (; i != NumDstElts; ++i)
1025        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
1026      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
1027                                                        ExtMask.size());
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[0], Mask.size());
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  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1104    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1105    return;
1106  }
1107
1108  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
1109    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
1110    return;
1111  }
1112
1113  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1114    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1115    if (LV.isObjCIvar() && !LV.isObjCArray())
1116      // Using array syntax to assigning to what an ivar points to is not
1117      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1118      LV.setObjCIvar(false);
1119    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1120      // Using array syntax to assigning to what global points to is not
1121      // same as assigning to the global itself. {id *G;} G[i] = 0;
1122      LV.setGlobalObjCRef(false);
1123    return;
1124  }
1125
1126  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
1127    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1128    // We don't know if member is an 'ivar', but this flag is looked at
1129    // only in the context of LV.isObjCIvar().
1130    LV.setObjCArray(E->getType()->isArrayType());
1131    return;
1132  }
1133}
1134
1135static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1136                                      const Expr *E, const VarDecl *VD) {
1137  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
1138         "Var decl must have external storage or be a file var decl!");
1139
1140  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1141  if (VD->getType()->isReferenceType())
1142    V = CGF.Builder.CreateLoad(V, "tmp");
1143  unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity();
1144  LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment);
1145  setObjCGCLValueClass(CGF.getContext(), E, LV);
1146  return LV;
1147}
1148
1149static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1150                                      const Expr *E, const FunctionDecl *FD) {
1151  llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
1152  if (!FD->hasPrototype()) {
1153    if (const FunctionProtoType *Proto =
1154            FD->getType()->getAs<FunctionProtoType>()) {
1155      // Ugly case: for a K&R-style definition, the type of the definition
1156      // isn't the same as the type of a use.  Correct for this with a
1157      // bitcast.
1158      QualType NoProtoType =
1159          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
1160      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
1161      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
1162    }
1163  }
1164  unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity();
1165  return CGF.MakeAddrLValue(V, E->getType(), Alignment);
1166}
1167
1168LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
1169  const NamedDecl *ND = E->getDecl();
1170  unsigned Alignment = CGF.getContext().getDeclAlign(ND).getQuantity();
1171
1172  if (ND->hasAttr<WeakRefAttr>()) {
1173    const ValueDecl *VD = cast<ValueDecl>(ND);
1174    llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
1175    return MakeAddrLValue(Aliasee, E->getType(), Alignment);
1176  }
1177
1178  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1179
1180    // Check if this is a global variable.
1181    if (VD->hasExternalStorage() || VD->isFileVarDecl())
1182      return EmitGlobalVarDeclLValue(*this, E, VD);
1183
1184    bool NonGCable = VD->hasLocalStorage() &&
1185                     !VD->getType()->isReferenceType() &&
1186                     !VD->hasAttr<BlocksAttr>();
1187
1188    llvm::Value *V = LocalDeclMap[VD];
1189    if (!V && VD->isStaticLocal())
1190      V = CGM.getStaticLocalDeclAddress(VD);
1191    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1192
1193    if (VD->hasAttr<BlocksAttr>()) {
1194      V = Builder.CreateStructGEP(V, 1, "forwarding");
1195      V = Builder.CreateLoad(V);
1196      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
1197                                  VD->getNameAsString());
1198    }
1199    if (VD->getType()->isReferenceType())
1200      V = Builder.CreateLoad(V, "tmp");
1201
1202    LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
1203    if (NonGCable) {
1204      LV.getQuals().removeObjCGCAttr();
1205      LV.setNonGC(true);
1206    }
1207    setObjCGCLValueClass(getContext(), E, LV);
1208    return LV;
1209  }
1210
1211  // If we're emitting an instance method as an independent lvalue,
1212  // we're actually emitting a member pointer.
1213  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1214    if (MD->isInstance()) {
1215      llvm::Value *V = CGM.getCXXABI().EmitMemberPointer(MD);
1216      return MakeAddrLValue(V, MD->getType(), Alignment);
1217    }
1218  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1219    return EmitFunctionDeclLValue(*this, E, FD);
1220
1221  // If we're emitting a field as an independent lvalue, we're
1222  // actually emitting a member pointer.
1223  if (const FieldDecl *FD = dyn_cast<FieldDecl>(ND)) {
1224    llvm::Value *V = CGM.getCXXABI().EmitMemberPointer(FD);
1225    return MakeAddrLValue(V, FD->getType(), Alignment);
1226  }
1227
1228  assert(false && "Unhandled DeclRefExpr");
1229
1230  // an invalid LValue, but the assert will
1231  // ensure that this point is never reached.
1232  return LValue();
1233}
1234
1235LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1236  unsigned Alignment =
1237    CGF.getContext().getDeclAlign(E->getDecl()).getQuantity();
1238  return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
1239}
1240
1241LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1242  // __extension__ doesn't affect lvalue-ness.
1243  if (E->getOpcode() == UO_Extension)
1244    return EmitLValue(E->getSubExpr());
1245
1246  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1247  switch (E->getOpcode()) {
1248  default: assert(0 && "Unknown unary operator lvalue!");
1249  case UO_Deref: {
1250    QualType T = E->getSubExpr()->getType()->getPointeeType();
1251    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1252
1253    LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
1254    LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
1255
1256    // We should not generate __weak write barrier on indirect reference
1257    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1258    // But, we continue to generate __strong write barrier on indirect write
1259    // into a pointer to object.
1260    if (getContext().getLangOptions().ObjC1 &&
1261        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1262        LV.isObjCWeak())
1263      LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1264    return LV;
1265  }
1266  case UO_Real:
1267  case UO_Imag: {
1268    LValue LV = EmitLValue(E->getSubExpr());
1269    unsigned Idx = E->getOpcode() == UO_Imag;
1270    return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
1271                                                    Idx, "idx"),
1272                          ExprTy);
1273  }
1274  case UO_PreInc:
1275  case UO_PreDec: {
1276    LValue LV = EmitLValue(E->getSubExpr());
1277    bool isInc = E->getOpcode() == UO_PreInc;
1278
1279    if (E->getType()->isAnyComplexType())
1280      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1281    else
1282      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1283    return LV;
1284  }
1285  }
1286}
1287
1288LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1289  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
1290                        E->getType());
1291}
1292
1293LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1294  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1295                        E->getType());
1296}
1297
1298
1299LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1300  switch (E->getIdentType()) {
1301  default:
1302    return EmitUnsupportedLValue(E, "predefined expression");
1303
1304  case PredefinedExpr::Func:
1305  case PredefinedExpr::Function:
1306  case PredefinedExpr::PrettyFunction: {
1307    unsigned Type = E->getIdentType();
1308    std::string GlobalVarName;
1309
1310    switch (Type) {
1311    default: assert(0 && "Invalid type");
1312    case PredefinedExpr::Func:
1313      GlobalVarName = "__func__.";
1314      break;
1315    case PredefinedExpr::Function:
1316      GlobalVarName = "__FUNCTION__.";
1317      break;
1318    case PredefinedExpr::PrettyFunction:
1319      GlobalVarName = "__PRETTY_FUNCTION__.";
1320      break;
1321    }
1322
1323    llvm::StringRef FnName = CurFn->getName();
1324    if (FnName.startswith("\01"))
1325      FnName = FnName.substr(1);
1326    GlobalVarName += FnName;
1327
1328    const Decl *CurDecl = CurCodeDecl;
1329    if (CurDecl == 0)
1330      CurDecl = getContext().getTranslationUnitDecl();
1331
1332    std::string FunctionName =
1333      PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl);
1334
1335    llvm::Constant *C =
1336      CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1337    return MakeAddrLValue(C, E->getType());
1338  }
1339  }
1340}
1341
1342llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1343  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1344
1345  // If we are not optimzing, don't collapse all calls to trap in the function
1346  // to the same call, that way, in the debugger they can see which operation
1347  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1348  // to just one per function to save on codesize.
1349  if (GCO.OptimizationLevel && TrapBB)
1350    return TrapBB;
1351
1352  llvm::BasicBlock *Cont = 0;
1353  if (HaveInsertPoint()) {
1354    Cont = createBasicBlock("cont");
1355    EmitBranch(Cont);
1356  }
1357  TrapBB = createBasicBlock("trap");
1358  EmitBlock(TrapBB);
1359
1360  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1361  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1362  TrapCall->setDoesNotReturn();
1363  TrapCall->setDoesNotThrow();
1364  Builder.CreateUnreachable();
1365
1366  if (Cont)
1367    EmitBlock(Cont);
1368  return TrapBB;
1369}
1370
1371/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1372/// array to pointer, return the array subexpression.
1373static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1374  // If this isn't just an array->pointer decay, bail out.
1375  const CastExpr *CE = dyn_cast<CastExpr>(E);
1376  if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay)
1377    return 0;
1378
1379  // If this is a decay from variable width array, bail out.
1380  const Expr *SubExpr = CE->getSubExpr();
1381  if (SubExpr->getType()->isVariableArrayType())
1382    return 0;
1383
1384  return SubExpr;
1385}
1386
1387LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1388  // The index must always be an integer, which is not an aggregate.  Emit it.
1389  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1390  QualType IdxTy  = E->getIdx()->getType();
1391  bool IdxSigned = IdxTy->isSignedIntegerType();
1392
1393  // If the base is a vector type, then we are forming a vector element lvalue
1394  // with this subscript.
1395  if (E->getBase()->getType()->isVectorType()) {
1396    // Emit the vector as an lvalue to get its address.
1397    LValue LHS = EmitLValue(E->getBase());
1398    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1399    Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vidx");
1400    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1401                                 E->getBase()->getType().getCVRQualifiers());
1402  }
1403
1404  // Extend or truncate the index type to 32 or 64-bits.
1405  if (!Idx->getType()->isIntegerTy(LLVMPointerWidth))
1406    Idx = Builder.CreateIntCast(Idx, IntPtrTy,
1407                                IdxSigned, "idxprom");
1408
1409  // FIXME: As llvm implements the object size checking, this can come out.
1410  if (CatchUndefined) {
1411    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1412      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1413        if (ICE->getCastKind() == CK_ArrayToPointerDecay) {
1414          if (const ConstantArrayType *CAT
1415              = getContext().getAsConstantArrayType(DRE->getType())) {
1416            llvm::APInt Size = CAT->getSize();
1417            llvm::BasicBlock *Cont = createBasicBlock("cont");
1418            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1419                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1420                                 Cont, getTrapBB());
1421            EmitBlock(Cont);
1422          }
1423        }
1424      }
1425    }
1426  }
1427
1428  // We know that the pointer points to a type of the correct size, unless the
1429  // size is a VLA or Objective-C interface.
1430  llvm::Value *Address = 0;
1431  if (const VariableArrayType *VAT =
1432        getContext().getAsVariableArrayType(E->getType())) {
1433    llvm::Value *VLASize = GetVLASize(VAT);
1434
1435    Idx = Builder.CreateMul(Idx, VLASize);
1436
1437    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1438
1439    // The base must be a pointer, which is not an aggregate.  Emit it.
1440    llvm::Value *Base = EmitScalarExpr(E->getBase());
1441
1442    Address = Builder.CreateInBoundsGEP(Builder.CreateBitCast(Base, i8PTy),
1443                                        Idx, "arrayidx");
1444    Address = Builder.CreateBitCast(Address, Base->getType());
1445  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1446    // Indexing over an interface, as in "NSString *P; P[4];"
1447    llvm::Value *InterfaceSize =
1448      llvm::ConstantInt::get(Idx->getType(),
1449          getContext().getTypeSizeInChars(OIT).getQuantity());
1450
1451    Idx = Builder.CreateMul(Idx, InterfaceSize);
1452
1453    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1454
1455    // The base must be a pointer, which is not an aggregate.  Emit it.
1456    llvm::Value *Base = EmitScalarExpr(E->getBase());
1457    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1458                                Idx, "arrayidx");
1459    Address = Builder.CreateBitCast(Address, Base->getType());
1460  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1461    // If this is A[i] where A is an array, the frontend will have decayed the
1462    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1463    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1464    // "gep x, i" here.  Emit one "gep A, 0, i".
1465    assert(Array->getType()->isArrayType() &&
1466           "Array to pointer decay must have array source type!");
1467    llvm::Value *ArrayPtr = EmitLValue(Array).getAddress();
1468    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1469    llvm::Value *Args[] = { Zero, Idx };
1470
1471    Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1472  } else {
1473    // The base must be a pointer, which is not an aggregate.  Emit it.
1474    llvm::Value *Base = EmitScalarExpr(E->getBase());
1475    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1476  }
1477
1478  QualType T = E->getBase()->getType()->getPointeeType();
1479  assert(!T.isNull() &&
1480         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1481
1482  LValue LV = MakeAddrLValue(Address, T);
1483  LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
1484
1485  if (getContext().getLangOptions().ObjC1 &&
1486      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1487    LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1488    setObjCGCLValueClass(getContext(), E, LV);
1489  }
1490  return LV;
1491}
1492
1493static
1494llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1495                                       llvm::SmallVector<unsigned, 4> &Elts) {
1496  llvm::SmallVector<llvm::Constant*, 4> CElts;
1497
1498  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1499  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1500    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1501
1502  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1503}
1504
1505LValue CodeGenFunction::
1506EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1507  // Emit the base vector as an l-value.
1508  LValue Base;
1509
1510  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1511  if (E->isArrow()) {
1512    // If it is a pointer to a vector, emit the address and form an lvalue with
1513    // it.
1514    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1515    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1516    Base = MakeAddrLValue(Ptr, PT->getPointeeType());
1517    Base.getQuals().removeObjCGCAttr();
1518  } else if (E->getBase()->isGLValue()) {
1519    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1520    // emit the base as an lvalue.
1521    assert(E->getBase()->getType()->isVectorType());
1522    Base = EmitLValue(E->getBase());
1523  } else {
1524    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1525    assert(E->getBase()->getType()->getAs<VectorType>() &&
1526           "Result must be a vector");
1527    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1528
1529    // Store the vector to memory (because LValue wants an address).
1530    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1531    Builder.CreateStore(Vec, VecMem);
1532    Base = MakeAddrLValue(VecMem, E->getBase()->getType());
1533  }
1534
1535  // Encode the element access list into a vector of unsigned indices.
1536  llvm::SmallVector<unsigned, 4> Indices;
1537  E->getEncodedElementAccess(Indices);
1538
1539  if (Base.isSimple()) {
1540    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1541    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1542                                    Base.getVRQualifiers());
1543  }
1544  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1545
1546  llvm::Constant *BaseElts = Base.getExtVectorElts();
1547  llvm::SmallVector<llvm::Constant *, 4> CElts;
1548
1549  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1550    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1551      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1552    else
1553      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1554  }
1555  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1556  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1557                                  Base.getVRQualifiers());
1558}
1559
1560LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1561  bool isNonGC = false;
1562  Expr *BaseExpr = E->getBase();
1563  llvm::Value *BaseValue = NULL;
1564  Qualifiers BaseQuals;
1565
1566  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1567  if (E->isArrow()) {
1568    BaseValue = EmitScalarExpr(BaseExpr);
1569    const PointerType *PTy =
1570      BaseExpr->getType()->getAs<PointerType>();
1571    BaseQuals = PTy->getPointeeType().getQualifiers();
1572  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1573             isa<ObjCImplicitSetterGetterRefExpr>(
1574               BaseExpr->IgnoreParens())) {
1575    RValue RV = EmitObjCPropertyGet(BaseExpr);
1576    BaseValue = RV.getAggregateAddr();
1577    BaseQuals = BaseExpr->getType().getQualifiers();
1578  } else {
1579    LValue BaseLV = EmitLValue(BaseExpr);
1580    if (BaseLV.isNonGC())
1581      isNonGC = true;
1582    // FIXME: this isn't right for bitfields.
1583    BaseValue = BaseLV.getAddress();
1584    QualType BaseTy = BaseExpr->getType();
1585    BaseQuals = BaseTy.getQualifiers();
1586  }
1587
1588  NamedDecl *ND = E->getMemberDecl();
1589  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1590    LValue LV = EmitLValueForField(BaseValue, Field,
1591                                   BaseQuals.getCVRQualifiers());
1592    LV.setNonGC(isNonGC);
1593    setObjCGCLValueClass(getContext(), E, LV);
1594    return LV;
1595  }
1596
1597  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1598    return EmitGlobalVarDeclLValue(*this, E, VD);
1599
1600  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1601    return EmitFunctionDeclLValue(*this, E, FD);
1602
1603  assert(false && "Unhandled member declaration!");
1604  return LValue();
1605}
1606
1607LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue,
1608                                              const FieldDecl *Field,
1609                                              unsigned CVRQualifiers) {
1610  const CGRecordLayout &RL =
1611    CGM.getTypes().getCGRecordLayout(Field->getParent());
1612  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1613  return LValue::MakeBitfield(BaseValue, Info,
1614                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1615}
1616
1617/// EmitLValueForAnonRecordField - Given that the field is a member of
1618/// an anonymous struct or union buried inside a record, and given
1619/// that the base value is a pointer to the enclosing record, derive
1620/// an lvalue for the ultimate field.
1621LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1622                                                     const FieldDecl *Field,
1623                                                     unsigned CVRQualifiers) {
1624  llvm::SmallVector<const FieldDecl *, 8> Path;
1625  Path.push_back(Field);
1626
1627  while (Field->getParent()->isAnonymousStructOrUnion()) {
1628    const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
1629    if (!isa<FieldDecl>(VD)) break;
1630    Field = cast<FieldDecl>(VD);
1631    Path.push_back(Field);
1632  }
1633
1634  llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
1635    I = Path.rbegin(), E = Path.rend();
1636  while (true) {
1637    LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
1638    if (++I == E) return LV;
1639
1640    assert(LV.isSimple());
1641    BaseValue = LV.getAddress();
1642    CVRQualifiers |= LV.getVRQualifiers();
1643  }
1644}
1645
1646LValue CodeGenFunction::EmitLValueForField(llvm::Value *BaseValue,
1647                                           const FieldDecl *Field,
1648                                           unsigned CVRQualifiers) {
1649  if (Field->isBitField())
1650    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1651
1652  const CGRecordLayout &RL =
1653    CGM.getTypes().getCGRecordLayout(Field->getParent());
1654  unsigned idx = RL.getLLVMFieldNo(Field);
1655  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1656
1657  // Match union field type.
1658  if (Field->getParent()->isUnion()) {
1659    const llvm::Type *FieldTy =
1660      CGM.getTypes().ConvertTypeForMem(Field->getType());
1661    const llvm::PointerType *BaseTy =
1662      cast<llvm::PointerType>(BaseValue->getType());
1663    unsigned AS = BaseTy->getAddressSpace();
1664    V = Builder.CreateBitCast(V,
1665                              llvm::PointerType::get(FieldTy, AS),
1666                              "tmp");
1667  }
1668  if (Field->getType()->isReferenceType())
1669    V = Builder.CreateLoad(V, "tmp");
1670
1671  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1672  LValue LV = MakeAddrLValue(V, Field->getType(), Alignment);
1673  LV.getQuals().addCVRQualifiers(CVRQualifiers);
1674
1675  // __weak attribute on a field is ignored.
1676  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
1677    LV.getQuals().removeObjCGCAttr();
1678
1679  return LV;
1680}
1681
1682LValue
1683CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue,
1684                                                  const FieldDecl *Field,
1685                                                  unsigned CVRQualifiers) {
1686  QualType FieldType = Field->getType();
1687
1688  if (!FieldType->isReferenceType())
1689    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1690
1691  const CGRecordLayout &RL =
1692    CGM.getTypes().getCGRecordLayout(Field->getParent());
1693  unsigned idx = RL.getLLVMFieldNo(Field);
1694  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1695
1696  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1697
1698  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1699  return MakeAddrLValue(V, FieldType, Alignment);
1700}
1701
1702LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
1703  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1704  const Expr *InitExpr = E->getInitializer();
1705  LValue Result = MakeAddrLValue(DeclPtr, E->getType());
1706
1707  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false, /*Init*/ true);
1708
1709  return Result;
1710}
1711
1712LValue
1713CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator *E) {
1714  if (E->isGLValue()) {
1715    if (int Cond = ConstantFoldsToSimpleInteger(E->getCond())) {
1716      Expr *Live = Cond == 1 ? E->getLHS() : E->getRHS();
1717      if (Live)
1718        return EmitLValue(Live);
1719    }
1720
1721    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1722    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1723    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1724
1725    if (E->getLHS())
1726      EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1727    else {
1728      Expr *save = E->getSAVE();
1729      assert(save && "VisitConditionalOperator - save is null");
1730      // Intentianlly not doing direct assignment to ConditionalSaveExprs[save]
1731      LValue SaveVal = EmitLValue(save);
1732      ConditionalSaveLValueExprs[save] = SaveVal;
1733      EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1734    }
1735
1736    // Any temporaries created here are conditional.
1737    BeginConditionalBranch();
1738    EmitBlock(LHSBlock);
1739    LValue LHS = EmitLValue(E->getTrueExpr());
1740
1741    EndConditionalBranch();
1742
1743    if (!LHS.isSimple())
1744      return EmitUnsupportedLValue(E, "conditional operator");
1745
1746    // FIXME: We shouldn't need an alloca for this.
1747    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1748    Builder.CreateStore(LHS.getAddress(), Temp);
1749    EmitBranch(ContBlock);
1750
1751    // Any temporaries created here are conditional.
1752    BeginConditionalBranch();
1753    EmitBlock(RHSBlock);
1754    LValue RHS = EmitLValue(E->getRHS());
1755    EndConditionalBranch();
1756    if (!RHS.isSimple())
1757      return EmitUnsupportedLValue(E, "conditional operator");
1758
1759    Builder.CreateStore(RHS.getAddress(), Temp);
1760    EmitBranch(ContBlock);
1761
1762    EmitBlock(ContBlock);
1763
1764    Temp = Builder.CreateLoad(Temp, "lv");
1765    return MakeAddrLValue(Temp, E->getType());
1766  }
1767
1768  // ?: here should be an aggregate.
1769  assert((hasAggregateLLVMType(E->getType()) &&
1770          !E->getType()->isAnyComplexType()) &&
1771         "Unexpected conditional operator!");
1772
1773  return EmitAggExprToLValue(E);
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_NoOp:
1792    if (E->getSubExpr()->Classify(getContext()).getKind()
1793                                          != Expr::Classification::CL_PRValue) {
1794      LValue LV = EmitLValue(E->getSubExpr());
1795      if (LV.isPropertyRef() || LV.isKVCRef()) {
1796        QualType QT = E->getSubExpr()->getType();
1797        RValue RV =
1798          LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
1799                             : EmitLoadOfKVCRefLValue(LV, QT);
1800        assert(!RV.isScalar() && "EmitCastLValue-scalar cast of property ref");
1801        llvm::Value *V = RV.getAggregateAddr();
1802        return MakeAddrLValue(V, QT);
1803      }
1804      return LV;
1805    }
1806    // Fall through to synthesize a temporary.
1807
1808  case CK_BitCast:
1809  case CK_ArrayToPointerDecay:
1810  case CK_FunctionToPointerDecay:
1811  case CK_NullToMemberPointer:
1812  case CK_NullToPointer:
1813  case CK_IntegralToPointer:
1814  case CK_PointerToIntegral:
1815  case CK_PointerToBoolean:
1816  case CK_VectorSplat:
1817  case CK_IntegralCast:
1818  case CK_IntegralToBoolean:
1819  case CK_IntegralToFloating:
1820  case CK_FloatingToIntegral:
1821  case CK_FloatingToBoolean:
1822  case CK_FloatingCast:
1823  case CK_FloatingRealToComplex:
1824  case CK_FloatingComplexToReal:
1825  case CK_FloatingComplexToBoolean:
1826  case CK_FloatingComplexCast:
1827  case CK_FloatingComplexToIntegralComplex:
1828  case CK_IntegralRealToComplex:
1829  case CK_IntegralComplexToReal:
1830  case CK_IntegralComplexToBoolean:
1831  case CK_IntegralComplexCast:
1832  case CK_IntegralComplexToFloatingComplex:
1833  case CK_DerivedToBaseMemberPointer:
1834  case CK_BaseToDerivedMemberPointer:
1835  case CK_MemberPointerToBoolean:
1836  case CK_AnyPointerToBlockPointerCast: {
1837    // These casts only produce lvalues when we're binding a reference to a
1838    // temporary realized from a (converted) pure rvalue. Emit the expression
1839    // as a value, copy it into a temporary, and return an lvalue referring to
1840    // that temporary.
1841    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
1842    EmitAnyExprToMem(E, V, false, false);
1843    return MakeAddrLValue(V, E->getType());
1844  }
1845
1846  case CK_Dynamic: {
1847    LValue LV = EmitLValue(E->getSubExpr());
1848    llvm::Value *V = LV.getAddress();
1849    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1850    return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
1851  }
1852
1853  case CK_ConstructorConversion:
1854  case CK_UserDefinedConversion:
1855  case CK_AnyPointerToObjCPointerCast:
1856    return EmitLValue(E->getSubExpr());
1857
1858  case CK_UncheckedDerivedToBase:
1859  case CK_DerivedToBase: {
1860    const RecordType *DerivedClassTy =
1861      E->getSubExpr()->getType()->getAs<RecordType>();
1862    CXXRecordDecl *DerivedClassDecl =
1863      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1864
1865    LValue LV = EmitLValue(E->getSubExpr());
1866    llvm::Value *This;
1867    if (LV.isPropertyRef() || LV.isKVCRef()) {
1868      QualType QT = E->getSubExpr()->getType();
1869      RValue RV =
1870        LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
1871                           : EmitLoadOfKVCRefLValue(LV, QT);
1872      assert (!RV.isScalar() && "EmitCastLValue");
1873      This = RV.getAggregateAddr();
1874    }
1875    else
1876      This = LV.getAddress();
1877
1878    // Perform the derived-to-base conversion
1879    llvm::Value *Base =
1880      GetAddressOfBaseClass(This, DerivedClassDecl,
1881                            E->path_begin(), E->path_end(),
1882                            /*NullCheckValue=*/false);
1883
1884    return MakeAddrLValue(Base, E->getType());
1885  }
1886  case CK_ToUnion:
1887    return EmitAggExprToLValue(E);
1888  case CK_BaseToDerived: {
1889    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1890    CXXRecordDecl *DerivedClassDecl =
1891      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1892
1893    LValue LV = EmitLValue(E->getSubExpr());
1894
1895    // Perform the base-to-derived conversion
1896    llvm::Value *Derived =
1897      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1898                               E->path_begin(), E->path_end(),
1899                               /*NullCheckValue=*/false);
1900
1901    return MakeAddrLValue(Derived, E->getType());
1902  }
1903  case CK_LValueBitCast: {
1904    // This must be a reinterpret_cast (or c-style equivalent).
1905    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1906
1907    LValue LV = EmitLValue(E->getSubExpr());
1908    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1909                                           ConvertType(CE->getTypeAsWritten()));
1910    return MakeAddrLValue(V, E->getType());
1911  }
1912  case CK_ObjCObjectLValueCast: {
1913    LValue LV = EmitLValue(E->getSubExpr());
1914    QualType ToType = getContext().getLValueReferenceType(E->getType());
1915    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1916                                           ConvertType(ToType));
1917    return MakeAddrLValue(V, E->getType());
1918  }
1919  }
1920
1921  llvm_unreachable("Unhandled lvalue cast kind?");
1922}
1923
1924LValue CodeGenFunction::EmitNullInitializationLValue(
1925                                              const CXXScalarValueInitExpr *E) {
1926  QualType Ty = E->getType();
1927  LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
1928  EmitNullInitialization(LV.getAddress(), Ty);
1929  return LV;
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    EmitAnyExpr(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->isAssignmentOp() && "unexpected binary l-value");
1988
1989  if (!hasAggregateLLVMType(E->getType())) {
1990    if (E->isCompoundAssignmentOp())
1991      return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
1992
1993    assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
1994
1995    // Emit the LHS as an l-value.
1996    LValue LV = EmitLValue(E->getLHS());
1997    // Store the value through the l-value.
1998    EmitStoreThroughLValue(EmitAnyExpr(E->getRHS()), LV, E->getType());
1999    return LV;
2000  }
2001
2002  if (E->getType()->isAnyComplexType())
2003    return EmitComplexAssignmentLValue(E);
2004
2005  // The compound assignment operators are not used for aggregates.
2006  assert(E->getOpcode() == BO_Assign && "aggregate compound assignment?");
2007
2008  return EmitAggExprToLValue(E);
2009}
2010
2011LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
2012  RValue RV = EmitCallExpr(E);
2013
2014  if (!RV.isScalar())
2015    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2016
2017  assert(E->getCallReturnType()->isReferenceType() &&
2018         "Can't have a scalar return unless the return type is a "
2019         "reference type!");
2020
2021  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2022}
2023
2024LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
2025  // FIXME: This shouldn't require another copy.
2026  return EmitAggExprToLValue(E);
2027}
2028
2029LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
2030  assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
2031         && "binding l-value to type which needs a temporary");
2032  AggValueSlot Slot = CreateAggTemp(E->getType(), "tmp");
2033  EmitCXXConstructExpr(E, Slot);
2034  return MakeAddrLValue(Slot.getAddr(), E->getType());
2035}
2036
2037LValue
2038CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
2039  return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
2040}
2041
2042LValue
2043CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
2044  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
2045  Slot.setLifetimeExternallyManaged();
2046  EmitAggExpr(E->getSubExpr(), Slot);
2047  EmitCXXTemporary(E->getTemporary(), Slot.getAddr());
2048  return MakeAddrLValue(Slot.getAddr(), E->getType());
2049}
2050
2051LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
2052  RValue RV = EmitObjCMessageExpr(E);
2053
2054  if (!RV.isScalar())
2055    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2056
2057  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2058         "Can't have a scalar return unless the return type is a "
2059         "reference type!");
2060
2061  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2062}
2063
2064LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2065  llvm::Value *V =
2066    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2067  return MakeAddrLValue(V, E->getType());
2068}
2069
2070llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2071                                             const ObjCIvarDecl *Ivar) {
2072  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2073}
2074
2075LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2076                                          llvm::Value *BaseValue,
2077                                          const ObjCIvarDecl *Ivar,
2078                                          unsigned CVRQualifiers) {
2079  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2080                                                   Ivar, CVRQualifiers);
2081}
2082
2083LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2084  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2085  llvm::Value *BaseValue = 0;
2086  const Expr *BaseExpr = E->getBase();
2087  Qualifiers BaseQuals;
2088  QualType ObjectTy;
2089  if (E->isArrow()) {
2090    BaseValue = EmitScalarExpr(BaseExpr);
2091    ObjectTy = BaseExpr->getType()->getPointeeType();
2092    BaseQuals = ObjectTy.getQualifiers();
2093  } else {
2094    LValue BaseLV = EmitLValue(BaseExpr);
2095    // FIXME: this isn't right for bitfields.
2096    BaseValue = BaseLV.getAddress();
2097    ObjectTy = BaseExpr->getType();
2098    BaseQuals = ObjectTy.getQualifiers();
2099  }
2100
2101  LValue LV =
2102    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2103                      BaseQuals.getCVRQualifiers());
2104  setObjCGCLValueClass(getContext(), E, LV);
2105  return LV;
2106}
2107
2108LValue
2109CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
2110  // This is a special l-value that just issues sends when we load or store
2111  // through it.
2112  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
2113}
2114
2115LValue CodeGenFunction::EmitObjCKVCRefLValue(
2116                                const ObjCImplicitSetterGetterRefExpr *E) {
2117  // This is a special l-value that just issues sends when we load or store
2118  // through it.
2119  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
2120}
2121
2122LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2123  // Can only get l-value for message expression returning aggregate type
2124  RValue RV = EmitAnyExprToTemp(E);
2125  return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2126}
2127
2128RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2129                                 ReturnValueSlot ReturnValue,
2130                                 CallExpr::const_arg_iterator ArgBeg,
2131                                 CallExpr::const_arg_iterator ArgEnd,
2132                                 const Decl *TargetDecl) {
2133  // Get the actual function type. The callee type will always be a pointer to
2134  // function type or a block pointer type.
2135  assert(CalleeType->isFunctionPointerType() &&
2136         "Call must have function pointer type!");
2137
2138  CalleeType = getContext().getCanonicalType(CalleeType);
2139
2140  const FunctionType *FnType
2141    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2142  QualType ResultType = FnType->getResultType();
2143
2144  CallArgList Args;
2145  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2146
2147  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2148                  Callee, ReturnValue, Args, TargetDecl);
2149}
2150
2151LValue CodeGenFunction::
2152EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2153  llvm::Value *BaseV;
2154  if (E->getOpcode() == BO_PtrMemI)
2155    BaseV = EmitScalarExpr(E->getLHS());
2156  else
2157    BaseV = EmitLValue(E->getLHS()).getAddress();
2158
2159  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2160
2161  const MemberPointerType *MPT
2162    = E->getRHS()->getType()->getAs<MemberPointerType>();
2163
2164  llvm::Value *AddV =
2165    CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT);
2166
2167  return MakeAddrLValue(AddV, MPT->getPointeeType());
2168}
2169
2170