CGExpr.cpp revision 83ce9d4a552987d34cbd500e983db8d770232379 
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(CGF.getContext()) == Expr::LV_Valid) {
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->getBase()->isLvalue(CGF.getContext()) != Expr::LV_Valid &&
239            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() && !VD->hasAttr<BlocksAttr>();
1185
1186    llvm::Value *V = LocalDeclMap[VD];
1187    if (!V && VD->isStaticLocal())
1188      V = CGM.getStaticLocalDeclAddress(VD);
1189    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
1190
1191    if (VD->hasAttr<BlocksAttr>()) {
1192      V = Builder.CreateStructGEP(V, 1, "forwarding");
1193      V = Builder.CreateLoad(V);
1194      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
1195                                  VD->getNameAsString());
1196    }
1197    if (VD->getType()->isReferenceType())
1198      V = Builder.CreateLoad(V, "tmp");
1199
1200    LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
1201    if (NonGCable) {
1202      LV.getQuals().removeObjCGCAttr();
1203      LV.setNonGC(true);
1204    }
1205    setObjCGCLValueClass(getContext(), E, LV);
1206    return LV;
1207  }
1208
1209  // If we're emitting an instance method as an independent lvalue,
1210  // we're actually emitting a member pointer.
1211  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1212    if (MD->isInstance()) {
1213      llvm::Value *V = CGM.getCXXABI().EmitMemberPointer(MD);
1214      return MakeAddrLValue(V, MD->getType(), Alignment);
1215    }
1216  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1217    return EmitFunctionDeclLValue(*this, E, FD);
1218
1219  // If we're emitting a field as an independent lvalue, we're
1220  // actually emitting a member pointer.
1221  if (const FieldDecl *FD = dyn_cast<FieldDecl>(ND)) {
1222    llvm::Value *V = CGM.getCXXABI().EmitMemberPointer(FD);
1223    return MakeAddrLValue(V, FD->getType(), Alignment);
1224  }
1225
1226  assert(false && "Unhandled DeclRefExpr");
1227
1228  // an invalid LValue, but the assert will
1229  // ensure that this point is never reached.
1230  return LValue();
1231}
1232
1233LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
1234  unsigned Alignment =
1235    CGF.getContext().getDeclAlign(E->getDecl()).getQuantity();
1236  return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
1237}
1238
1239LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
1240  // __extension__ doesn't affect lvalue-ness.
1241  if (E->getOpcode() == UO_Extension)
1242    return EmitLValue(E->getSubExpr());
1243
1244  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
1245  switch (E->getOpcode()) {
1246  default: assert(0 && "Unknown unary operator lvalue!");
1247  case UO_Deref: {
1248    QualType T = E->getSubExpr()->getType()->getPointeeType();
1249    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
1250
1251    LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
1252    LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
1253
1254    // We should not generate __weak write barrier on indirect reference
1255    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
1256    // But, we continue to generate __strong write barrier on indirect write
1257    // into a pointer to object.
1258    if (getContext().getLangOptions().ObjC1 &&
1259        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
1260        LV.isObjCWeak())
1261      LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1262    return LV;
1263  }
1264  case UO_Real:
1265  case UO_Imag: {
1266    LValue LV = EmitLValue(E->getSubExpr());
1267    unsigned Idx = E->getOpcode() == UO_Imag;
1268    return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
1269                                                    Idx, "idx"),
1270                          ExprTy);
1271  }
1272  case UO_PreInc:
1273  case UO_PreDec: {
1274    LValue LV = EmitLValue(E->getSubExpr());
1275    bool isInc = E->getOpcode() == UO_PreInc;
1276
1277    if (E->getType()->isAnyComplexType())
1278      EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
1279    else
1280      EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
1281    return LV;
1282  }
1283  }
1284}
1285
1286LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
1287  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
1288                        E->getType());
1289}
1290
1291LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
1292  return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
1293                        E->getType());
1294}
1295
1296
1297LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1298  switch (E->getIdentType()) {
1299  default:
1300    return EmitUnsupportedLValue(E, "predefined expression");
1301
1302  case PredefinedExpr::Func:
1303  case PredefinedExpr::Function:
1304  case PredefinedExpr::PrettyFunction: {
1305    unsigned Type = E->getIdentType();
1306    std::string GlobalVarName;
1307
1308    switch (Type) {
1309    default: assert(0 && "Invalid type");
1310    case PredefinedExpr::Func:
1311      GlobalVarName = "__func__.";
1312      break;
1313    case PredefinedExpr::Function:
1314      GlobalVarName = "__FUNCTION__.";
1315      break;
1316    case PredefinedExpr::PrettyFunction:
1317      GlobalVarName = "__PRETTY_FUNCTION__.";
1318      break;
1319    }
1320
1321    llvm::StringRef FnName = CurFn->getName();
1322    if (FnName.startswith("\01"))
1323      FnName = FnName.substr(1);
1324    GlobalVarName += FnName;
1325
1326    const Decl *CurDecl = CurCodeDecl;
1327    if (CurDecl == 0)
1328      CurDecl = getContext().getTranslationUnitDecl();
1329
1330    std::string FunctionName =
1331      PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl);
1332
1333    llvm::Constant *C =
1334      CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1335    return MakeAddrLValue(C, E->getType());
1336  }
1337  }
1338}
1339
1340llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1341  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1342
1343  // If we are not optimzing, don't collapse all calls to trap in the function
1344  // to the same call, that way, in the debugger they can see which operation
1345  // did in fact fail.  If we are optimizing, we collapse all calls to trap down
1346  // to just one per function to save on codesize.
1347  if (GCO.OptimizationLevel && TrapBB)
1348    return TrapBB;
1349
1350  llvm::BasicBlock *Cont = 0;
1351  if (HaveInsertPoint()) {
1352    Cont = createBasicBlock("cont");
1353    EmitBranch(Cont);
1354  }
1355  TrapBB = createBasicBlock("trap");
1356  EmitBlock(TrapBB);
1357
1358  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1359  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1360  TrapCall->setDoesNotReturn();
1361  TrapCall->setDoesNotThrow();
1362  Builder.CreateUnreachable();
1363
1364  if (Cont)
1365    EmitBlock(Cont);
1366  return TrapBB;
1367}
1368
1369/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
1370/// array to pointer, return the array subexpression.
1371static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
1372  // If this isn't just an array->pointer decay, bail out.
1373  const CastExpr *CE = dyn_cast<CastExpr>(E);
1374  if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay)
1375    return 0;
1376
1377  // If this is a decay from variable width array, bail out.
1378  const Expr *SubExpr = CE->getSubExpr();
1379  if (SubExpr->getType()->isVariableArrayType())
1380    return 0;
1381
1382  return SubExpr;
1383}
1384
1385LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1386  // The index must always be an integer, which is not an aggregate.  Emit it.
1387  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1388  QualType IdxTy  = E->getIdx()->getType();
1389  bool IdxSigned = IdxTy->isSignedIntegerType();
1390
1391  // If the base is a vector type, then we are forming a vector element lvalue
1392  // with this subscript.
1393  if (E->getBase()->getType()->isVectorType()) {
1394    // Emit the vector as an lvalue to get its address.
1395    LValue LHS = EmitLValue(E->getBase());
1396    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1397    Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vidx");
1398    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1399                                 E->getBase()->getType().getCVRQualifiers());
1400  }
1401
1402  // Extend or truncate the index type to 32 or 64-bits.
1403  if (!Idx->getType()->isIntegerTy(LLVMPointerWidth))
1404    Idx = Builder.CreateIntCast(Idx, IntPtrTy,
1405                                IdxSigned, "idxprom");
1406
1407  // FIXME: As llvm implements the object size checking, this can come out.
1408  if (CatchUndefined) {
1409    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
1410      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1411        if (ICE->getCastKind() == CK_ArrayToPointerDecay) {
1412          if (const ConstantArrayType *CAT
1413              = getContext().getAsConstantArrayType(DRE->getType())) {
1414            llvm::APInt Size = CAT->getSize();
1415            llvm::BasicBlock *Cont = createBasicBlock("cont");
1416            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1417                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1418                                 Cont, getTrapBB());
1419            EmitBlock(Cont);
1420          }
1421        }
1422      }
1423    }
1424  }
1425
1426  // We know that the pointer points to a type of the correct size, unless the
1427  // size is a VLA or Objective-C interface.
1428  llvm::Value *Address = 0;
1429  if (const VariableArrayType *VAT =
1430        getContext().getAsVariableArrayType(E->getType())) {
1431    llvm::Value *VLASize = GetVLASize(VAT);
1432
1433    Idx = Builder.CreateMul(Idx, VLASize);
1434
1435    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1436
1437    // The base must be a pointer, which is not an aggregate.  Emit it.
1438    llvm::Value *Base = EmitScalarExpr(E->getBase());
1439
1440    Address = Builder.CreateInBoundsGEP(Builder.CreateBitCast(Base, i8PTy),
1441                                        Idx, "arrayidx");
1442    Address = Builder.CreateBitCast(Address, Base->getType());
1443  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
1444    // Indexing over an interface, as in "NSString *P; P[4];"
1445    llvm::Value *InterfaceSize =
1446      llvm::ConstantInt::get(Idx->getType(),
1447          getContext().getTypeSizeInChars(OIT).getQuantity());
1448
1449    Idx = Builder.CreateMul(Idx, InterfaceSize);
1450
1451    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1452
1453    // The base must be a pointer, which is not an aggregate.  Emit it.
1454    llvm::Value *Base = EmitScalarExpr(E->getBase());
1455    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1456                                Idx, "arrayidx");
1457    Address = Builder.CreateBitCast(Address, Base->getType());
1458  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
1459    // If this is A[i] where A is an array, the frontend will have decayed the
1460    // base to be a ArrayToPointerDecay implicit cast.  While correct, it is
1461    // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
1462    // "gep x, i" here.  Emit one "gep A, 0, i".
1463    assert(Array->getType()->isArrayType() &&
1464           "Array to pointer decay must have array source type!");
1465    llvm::Value *ArrayPtr = EmitLValue(Array).getAddress();
1466    llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
1467    llvm::Value *Args[] = { Zero, Idx };
1468
1469    Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
1470  } else {
1471    // The base must be a pointer, which is not an aggregate.  Emit it.
1472    llvm::Value *Base = EmitScalarExpr(E->getBase());
1473    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1474  }
1475
1476  QualType T = E->getBase()->getType()->getPointeeType();
1477  assert(!T.isNull() &&
1478         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1479
1480  LValue LV = MakeAddrLValue(Address, T);
1481  LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
1482
1483  if (getContext().getLangOptions().ObjC1 &&
1484      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1485    LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
1486    setObjCGCLValueClass(getContext(), E, LV);
1487  }
1488  return LV;
1489}
1490
1491static
1492llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1493                                       llvm::SmallVector<unsigned, 4> &Elts) {
1494  llvm::SmallVector<llvm::Constant*, 4> CElts;
1495
1496  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1497  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1498    CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i]));
1499
1500  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1501}
1502
1503LValue CodeGenFunction::
1504EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1505  // Emit the base vector as an l-value.
1506  LValue Base;
1507
1508  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1509  if (E->isArrow()) {
1510    // If it is a pointer to a vector, emit the address and form an lvalue with
1511    // it.
1512    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1513    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1514    Base = MakeAddrLValue(Ptr, PT->getPointeeType());
1515    Base.getQuals().removeObjCGCAttr();
1516  } else if (E->getBase()->isLvalue(getContext()) == Expr::LV_Valid) {
1517    // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
1518    // emit the base as an lvalue.
1519    assert(E->getBase()->getType()->isVectorType());
1520    Base = EmitLValue(E->getBase());
1521  } else {
1522    // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
1523    assert(E->getBase()->getType()->getAs<VectorType>() &&
1524           "Result must be a vector");
1525    llvm::Value *Vec = EmitScalarExpr(E->getBase());
1526
1527    // Store the vector to memory (because LValue wants an address).
1528    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
1529    Builder.CreateStore(Vec, VecMem);
1530    Base = MakeAddrLValue(VecMem, E->getBase()->getType());
1531  }
1532
1533  // Encode the element access list into a vector of unsigned indices.
1534  llvm::SmallVector<unsigned, 4> Indices;
1535  E->getEncodedElementAccess(Indices);
1536
1537  if (Base.isSimple()) {
1538    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1539    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1540                                    Base.getVRQualifiers());
1541  }
1542  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1543
1544  llvm::Constant *BaseElts = Base.getExtVectorElts();
1545  llvm::SmallVector<llvm::Constant *, 4> CElts;
1546
1547  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1548    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1549      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1550    else
1551      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1552  }
1553  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1554  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1555                                  Base.getVRQualifiers());
1556}
1557
1558LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1559  bool isNonGC = false;
1560  Expr *BaseExpr = E->getBase();
1561  llvm::Value *BaseValue = NULL;
1562  Qualifiers BaseQuals;
1563
1564  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1565  if (E->isArrow()) {
1566    BaseValue = EmitScalarExpr(BaseExpr);
1567    const PointerType *PTy =
1568      BaseExpr->getType()->getAs<PointerType>();
1569    BaseQuals = PTy->getPointeeType().getQualifiers();
1570  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1571             isa<ObjCImplicitSetterGetterRefExpr>(
1572               BaseExpr->IgnoreParens())) {
1573    RValue RV = EmitObjCPropertyGet(BaseExpr);
1574    BaseValue = RV.getAggregateAddr();
1575    BaseQuals = BaseExpr->getType().getQualifiers();
1576  } else {
1577    LValue BaseLV = EmitLValue(BaseExpr);
1578    if (BaseLV.isNonGC())
1579      isNonGC = true;
1580    // FIXME: this isn't right for bitfields.
1581    BaseValue = BaseLV.getAddress();
1582    QualType BaseTy = BaseExpr->getType();
1583    BaseQuals = BaseTy.getQualifiers();
1584  }
1585
1586  NamedDecl *ND = E->getMemberDecl();
1587  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1588    LValue LV = EmitLValueForField(BaseValue, Field,
1589                                   BaseQuals.getCVRQualifiers());
1590    LV.setNonGC(isNonGC);
1591    setObjCGCLValueClass(getContext(), E, LV);
1592    return LV;
1593  }
1594
1595  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1596    return EmitGlobalVarDeclLValue(*this, E, VD);
1597
1598  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1599    return EmitFunctionDeclLValue(*this, E, FD);
1600
1601  assert(false && "Unhandled member declaration!");
1602  return LValue();
1603}
1604
1605LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue,
1606                                              const FieldDecl *Field,
1607                                              unsigned CVRQualifiers) {
1608  const CGRecordLayout &RL =
1609    CGM.getTypes().getCGRecordLayout(Field->getParent());
1610  const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
1611  return LValue::MakeBitfield(BaseValue, Info,
1612                             Field->getType().getCVRQualifiers()|CVRQualifiers);
1613}
1614
1615/// EmitLValueForAnonRecordField - Given that the field is a member of
1616/// an anonymous struct or union buried inside a record, and given
1617/// that the base value is a pointer to the enclosing record, derive
1618/// an lvalue for the ultimate field.
1619LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
1620                                                     const FieldDecl *Field,
1621                                                     unsigned CVRQualifiers) {
1622  llvm::SmallVector<const FieldDecl *, 8> Path;
1623  Path.push_back(Field);
1624
1625  while (Field->getParent()->isAnonymousStructOrUnion()) {
1626    const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
1627    if (!isa<FieldDecl>(VD)) break;
1628    Field = cast<FieldDecl>(VD);
1629    Path.push_back(Field);
1630  }
1631
1632  llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
1633    I = Path.rbegin(), E = Path.rend();
1634  while (true) {
1635    LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
1636    if (++I == E) return LV;
1637
1638    assert(LV.isSimple());
1639    BaseValue = LV.getAddress();
1640    CVRQualifiers |= LV.getVRQualifiers();
1641  }
1642}
1643
1644LValue CodeGenFunction::EmitLValueForField(llvm::Value *BaseValue,
1645                                           const FieldDecl *Field,
1646                                           unsigned CVRQualifiers) {
1647  if (Field->isBitField())
1648    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1649
1650  const CGRecordLayout &RL =
1651    CGM.getTypes().getCGRecordLayout(Field->getParent());
1652  unsigned idx = RL.getLLVMFieldNo(Field);
1653  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1654
1655  // Match union field type.
1656  if (Field->getParent()->isUnion()) {
1657    const llvm::Type *FieldTy =
1658      CGM.getTypes().ConvertTypeForMem(Field->getType());
1659    const llvm::PointerType *BaseTy =
1660      cast<llvm::PointerType>(BaseValue->getType());
1661    unsigned AS = BaseTy->getAddressSpace();
1662    V = Builder.CreateBitCast(V,
1663                              llvm::PointerType::get(FieldTy, AS),
1664                              "tmp");
1665  }
1666  if (Field->getType()->isReferenceType())
1667    V = Builder.CreateLoad(V, "tmp");
1668
1669  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1670  LValue LV = MakeAddrLValue(V, Field->getType(), Alignment);
1671  LV.getQuals().addCVRQualifiers(CVRQualifiers);
1672
1673  // __weak attribute on a field is ignored.
1674  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
1675    LV.getQuals().removeObjCGCAttr();
1676
1677  return LV;
1678}
1679
1680LValue
1681CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue,
1682                                                  const FieldDecl *Field,
1683                                                  unsigned CVRQualifiers) {
1684  QualType FieldType = Field->getType();
1685
1686  if (!FieldType->isReferenceType())
1687    return EmitLValueForField(BaseValue, Field, CVRQualifiers);
1688
1689  const CGRecordLayout &RL =
1690    CGM.getTypes().getCGRecordLayout(Field->getParent());
1691  unsigned idx = RL.getLLVMFieldNo(Field);
1692  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1693
1694  assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
1695
1696  unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
1697  return MakeAddrLValue(V, FieldType, Alignment);
1698}
1699
1700LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
1701  llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
1702  const Expr *InitExpr = E->getInitializer();
1703  LValue Result = MakeAddrLValue(DeclPtr, E->getType());
1704
1705  EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false, /*Init*/ true);
1706
1707  return Result;
1708}
1709
1710LValue
1711CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator *E) {
1712  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1713    if (int Cond = ConstantFoldsToSimpleInteger(E->getCond())) {
1714      Expr *Live = Cond == 1 ? E->getLHS() : E->getRHS();
1715      if (Live)
1716        return EmitLValue(Live);
1717    }
1718
1719    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1720    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1721    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1722
1723    if (E->getLHS())
1724      EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1725    else {
1726      Expr *save = E->getSAVE();
1727      assert(save && "VisitConditionalOperator - save is null");
1728      // Intentianlly not doing direct assignment to ConditionalSaveExprs[save]
1729      LValue SaveVal = EmitLValue(save);
1730      ConditionalSaveLValueExprs[save] = SaveVal;
1731      EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1732    }
1733
1734    // Any temporaries created here are conditional.
1735    BeginConditionalBranch();
1736    EmitBlock(LHSBlock);
1737    LValue LHS = EmitLValue(E->getTrueExpr());
1738
1739    EndConditionalBranch();
1740
1741    if (!LHS.isSimple())
1742      return EmitUnsupportedLValue(E, "conditional operator");
1743
1744    // FIXME: We shouldn't need an alloca for this.
1745    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1746    Builder.CreateStore(LHS.getAddress(), Temp);
1747    EmitBranch(ContBlock);
1748
1749    // Any temporaries created here are conditional.
1750    BeginConditionalBranch();
1751    EmitBlock(RHSBlock);
1752    LValue RHS = EmitLValue(E->getRHS());
1753    EndConditionalBranch();
1754    if (!RHS.isSimple())
1755      return EmitUnsupportedLValue(E, "conditional operator");
1756
1757    Builder.CreateStore(RHS.getAddress(), Temp);
1758    EmitBranch(ContBlock);
1759
1760    EmitBlock(ContBlock);
1761
1762    Temp = Builder.CreateLoad(Temp, "lv");
1763    return MakeAddrLValue(Temp, E->getType());
1764  }
1765
1766  // ?: here should be an aggregate.
1767  assert((hasAggregateLLVMType(E->getType()) &&
1768          !E->getType()->isAnyComplexType()) &&
1769         "Unexpected conditional operator!");
1770
1771  return EmitAggExprToLValue(E);
1772}
1773
1774/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1775/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1776/// otherwise if a cast is needed by the code generator in an lvalue context,
1777/// then it must mean that we need the address of an aggregate in order to
1778/// access one of its fields.  This can happen for all the reasons that casts
1779/// are permitted with aggregate result, including noop aggregate casts, and
1780/// cast from scalar to union.
1781LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1782  switch (E->getCastKind()) {
1783  case CK_ToVoid:
1784    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1785
1786  case CK_Dependent:
1787    llvm_unreachable("dependent cast kind in IR gen!");
1788
1789  case CK_NoOp:
1790    if (E->getSubExpr()->Classify(getContext()).getKind()
1791                                          != Expr::Classification::CL_PRValue) {
1792      LValue LV = EmitLValue(E->getSubExpr());
1793      if (LV.isPropertyRef() || LV.isKVCRef()) {
1794        QualType QT = E->getSubExpr()->getType();
1795        RValue RV =
1796          LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
1797                             : EmitLoadOfKVCRefLValue(LV, QT);
1798        assert(!RV.isScalar() && "EmitCastLValue-scalar cast of property ref");
1799        llvm::Value *V = RV.getAggregateAddr();
1800        return MakeAddrLValue(V, QT);
1801      }
1802      return LV;
1803    }
1804    // Fall through to synthesize a temporary.
1805
1806  case CK_BitCast:
1807  case CK_ArrayToPointerDecay:
1808  case CK_FunctionToPointerDecay:
1809  case CK_NullToMemberPointer:
1810  case CK_NullToPointer:
1811  case CK_IntegralToPointer:
1812  case CK_PointerToIntegral:
1813  case CK_PointerToBoolean:
1814  case CK_VectorSplat:
1815  case CK_IntegralCast:
1816  case CK_IntegralToBoolean:
1817  case CK_IntegralToFloating:
1818  case CK_FloatingToIntegral:
1819  case CK_FloatingToBoolean:
1820  case CK_FloatingCast:
1821  case CK_FloatingRealToComplex:
1822  case CK_FloatingComplexToReal:
1823  case CK_FloatingComplexToBoolean:
1824  case CK_FloatingComplexCast:
1825  case CK_FloatingComplexToIntegralComplex:
1826  case CK_IntegralRealToComplex:
1827  case CK_IntegralComplexToReal:
1828  case CK_IntegralComplexToBoolean:
1829  case CK_IntegralComplexCast:
1830  case CK_IntegralComplexToFloatingComplex:
1831  case CK_DerivedToBaseMemberPointer:
1832  case CK_BaseToDerivedMemberPointer:
1833  case CK_MemberPointerToBoolean:
1834  case CK_AnyPointerToBlockPointerCast: {
1835    // These casts only produce lvalues when we're binding a reference to a
1836    // temporary realized from a (converted) pure rvalue. Emit the expression
1837    // as a value, copy it into a temporary, and return an lvalue referring to
1838    // that temporary.
1839    llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
1840    EmitAnyExprToMem(E, V, false, false);
1841    return MakeAddrLValue(V, E->getType());
1842  }
1843
1844  case CK_Dynamic: {
1845    LValue LV = EmitLValue(E->getSubExpr());
1846    llvm::Value *V = LV.getAddress();
1847    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1848    return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
1849  }
1850
1851  case CK_ConstructorConversion:
1852  case CK_UserDefinedConversion:
1853  case CK_AnyPointerToObjCPointerCast:
1854    return EmitLValue(E->getSubExpr());
1855
1856  case CK_UncheckedDerivedToBase:
1857  case CK_DerivedToBase: {
1858    const RecordType *DerivedClassTy =
1859      E->getSubExpr()->getType()->getAs<RecordType>();
1860    CXXRecordDecl *DerivedClassDecl =
1861      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1862
1863    LValue LV = EmitLValue(E->getSubExpr());
1864    llvm::Value *This;
1865    if (LV.isPropertyRef() || LV.isKVCRef()) {
1866      QualType QT = E->getSubExpr()->getType();
1867      RValue RV =
1868        LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
1869                           : EmitLoadOfKVCRefLValue(LV, QT);
1870      assert (!RV.isScalar() && "EmitCastLValue");
1871      This = RV.getAggregateAddr();
1872    }
1873    else
1874      This = LV.getAddress();
1875
1876    // Perform the derived-to-base conversion
1877    llvm::Value *Base =
1878      GetAddressOfBaseClass(This, DerivedClassDecl,
1879                            E->path_begin(), E->path_end(),
1880                            /*NullCheckValue=*/false);
1881
1882    return MakeAddrLValue(Base, E->getType());
1883  }
1884  case CK_ToUnion:
1885    return EmitAggExprToLValue(E);
1886  case CK_BaseToDerived: {
1887    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1888    CXXRecordDecl *DerivedClassDecl =
1889      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1890
1891    LValue LV = EmitLValue(E->getSubExpr());
1892
1893    // Perform the base-to-derived conversion
1894    llvm::Value *Derived =
1895      GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
1896                               E->path_begin(), E->path_end(),
1897                               /*NullCheckValue=*/false);
1898
1899    return MakeAddrLValue(Derived, E->getType());
1900  }
1901  case CK_LValueBitCast: {
1902    // This must be a reinterpret_cast (or c-style equivalent).
1903    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1904
1905    LValue LV = EmitLValue(E->getSubExpr());
1906    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1907                                           ConvertType(CE->getTypeAsWritten()));
1908    return MakeAddrLValue(V, E->getType());
1909  }
1910  case CK_ObjCObjectLValueCast: {
1911    LValue LV = EmitLValue(E->getSubExpr());
1912    QualType ToType = getContext().getLValueReferenceType(E->getType());
1913    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1914                                           ConvertType(ToType));
1915    return MakeAddrLValue(V, E->getType());
1916  }
1917  }
1918
1919  llvm_unreachable("Unhandled lvalue cast kind?");
1920}
1921
1922LValue CodeGenFunction::EmitNullInitializationLValue(
1923                                              const CXXScalarValueInitExpr *E) {
1924  QualType Ty = E->getType();
1925  LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
1926  EmitNullInitialization(LV.getAddress(), Ty);
1927  return LV;
1928}
1929
1930//===--------------------------------------------------------------------===//
1931//                             Expression Emission
1932//===--------------------------------------------------------------------===//
1933
1934
1935RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
1936                                     ReturnValueSlot ReturnValue) {
1937  // Builtins never have block type.
1938  if (E->getCallee()->getType()->isBlockPointerType())
1939    return EmitBlockCallExpr(E, ReturnValue);
1940
1941  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1942    return EmitCXXMemberCallExpr(CE, ReturnValue);
1943
1944  const Decl *TargetDecl = 0;
1945  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1946    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1947      TargetDecl = DRE->getDecl();
1948      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1949        if (unsigned builtinID = FD->getBuiltinID())
1950          return EmitBuiltinExpr(FD, builtinID, E);
1951    }
1952  }
1953
1954  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1955    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1956      return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
1957
1958  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1959    // C++ [expr.pseudo]p1:
1960    //   The result shall only be used as the operand for the function call
1961    //   operator (), and the result of such a call has type void. The only
1962    //   effect is the evaluation of the postfix-expression before the dot or
1963    //   arrow.
1964    EmitScalarExpr(E->getCallee());
1965    return RValue::get(0);
1966  }
1967
1968  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1969  return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
1970                  E->arg_begin(), E->arg_end(), TargetDecl);
1971}
1972
1973LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1974  // Comma expressions just emit their LHS then their RHS as an l-value.
1975  if (E->getOpcode() == BO_Comma) {
1976    EmitAnyExpr(E->getLHS());
1977    EnsureInsertPoint();
1978    return EmitLValue(E->getRHS());
1979  }
1980
1981  if (E->getOpcode() == BO_PtrMemD ||
1982      E->getOpcode() == BO_PtrMemI)
1983    return EmitPointerToDataMemberBinaryExpr(E);
1984
1985  assert(E->isAssignmentOp() && "unexpected binary l-value");
1986
1987  if (!hasAggregateLLVMType(E->getType())) {
1988    if (E->isCompoundAssignmentOp())
1989      return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
1990
1991    assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
1992
1993    // Emit the LHS as an l-value.
1994    LValue LV = EmitLValue(E->getLHS());
1995    // Store the value through the l-value.
1996    EmitStoreThroughLValue(EmitAnyExpr(E->getRHS()), LV, E->getType());
1997    return LV;
1998  }
1999
2000  if (E->getType()->isAnyComplexType())
2001    return EmitComplexAssignmentLValue(E);
2002
2003  // The compound assignment operators are not used for aggregates.
2004  assert(E->getOpcode() == BO_Assign && "aggregate compound assignment?");
2005
2006  return EmitAggExprToLValue(E);
2007}
2008
2009LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
2010  RValue RV = EmitCallExpr(E);
2011
2012  if (!RV.isScalar())
2013    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2014
2015  assert(E->getCallReturnType()->isReferenceType() &&
2016         "Can't have a scalar return unless the return type is a "
2017         "reference type!");
2018
2019  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2020}
2021
2022LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
2023  // FIXME: This shouldn't require another copy.
2024  return EmitAggExprToLValue(E);
2025}
2026
2027LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
2028  assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
2029         && "binding l-value to type which needs a temporary");
2030  AggValueSlot Slot = CreateAggTemp(E->getType(), "tmp");
2031  EmitCXXConstructExpr(E, Slot);
2032  return MakeAddrLValue(Slot.getAddr(), E->getType());
2033}
2034
2035LValue
2036CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
2037  return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
2038}
2039
2040LValue
2041CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
2042  AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
2043  Slot.setLifetimeExternallyManaged();
2044  EmitAggExpr(E->getSubExpr(), Slot);
2045  EmitCXXTemporary(E->getTemporary(), Slot.getAddr());
2046  return MakeAddrLValue(Slot.getAddr(), E->getType());
2047}
2048
2049LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
2050  RValue RV = EmitObjCMessageExpr(E);
2051
2052  if (!RV.isScalar())
2053    return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2054
2055  assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
2056         "Can't have a scalar return unless the return type is a "
2057         "reference type!");
2058
2059  return MakeAddrLValue(RV.getScalarVal(), E->getType());
2060}
2061
2062LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
2063  llvm::Value *V =
2064    CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
2065  return MakeAddrLValue(V, E->getType());
2066}
2067
2068llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2069                                             const ObjCIvarDecl *Ivar) {
2070  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
2071}
2072
2073LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
2074                                          llvm::Value *BaseValue,
2075                                          const ObjCIvarDecl *Ivar,
2076                                          unsigned CVRQualifiers) {
2077  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
2078                                                   Ivar, CVRQualifiers);
2079}
2080
2081LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
2082  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
2083  llvm::Value *BaseValue = 0;
2084  const Expr *BaseExpr = E->getBase();
2085  Qualifiers BaseQuals;
2086  QualType ObjectTy;
2087  if (E->isArrow()) {
2088    BaseValue = EmitScalarExpr(BaseExpr);
2089    ObjectTy = BaseExpr->getType()->getPointeeType();
2090    BaseQuals = ObjectTy.getQualifiers();
2091  } else {
2092    LValue BaseLV = EmitLValue(BaseExpr);
2093    // FIXME: this isn't right for bitfields.
2094    BaseValue = BaseLV.getAddress();
2095    ObjectTy = BaseExpr->getType();
2096    BaseQuals = ObjectTy.getQualifiers();
2097  }
2098
2099  LValue LV =
2100    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
2101                      BaseQuals.getCVRQualifiers());
2102  setObjCGCLValueClass(getContext(), E, LV);
2103  return LV;
2104}
2105
2106LValue
2107CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
2108  // This is a special l-value that just issues sends when we load or store
2109  // through it.
2110  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
2111}
2112
2113LValue CodeGenFunction::EmitObjCKVCRefLValue(
2114                                const ObjCImplicitSetterGetterRefExpr *E) {
2115  // This is a special l-value that just issues sends when we load or store
2116  // through it.
2117  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
2118}
2119
2120LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
2121  // Can only get l-value for message expression returning aggregate type
2122  RValue RV = EmitAnyExprToTemp(E);
2123  return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
2124}
2125
2126RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
2127                                 ReturnValueSlot ReturnValue,
2128                                 CallExpr::const_arg_iterator ArgBeg,
2129                                 CallExpr::const_arg_iterator ArgEnd,
2130                                 const Decl *TargetDecl) {
2131  // Get the actual function type. The callee type will always be a pointer to
2132  // function type or a block pointer type.
2133  assert(CalleeType->isFunctionPointerType() &&
2134         "Call must have function pointer type!");
2135
2136  CalleeType = getContext().getCanonicalType(CalleeType);
2137
2138  const FunctionType *FnType
2139    = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
2140  QualType ResultType = FnType->getResultType();
2141
2142  CallArgList Args;
2143  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
2144
2145  return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
2146                  Callee, ReturnValue, Args, TargetDecl);
2147}
2148
2149LValue CodeGenFunction::
2150EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
2151  llvm::Value *BaseV;
2152  if (E->getOpcode() == BO_PtrMemI)
2153    BaseV = EmitScalarExpr(E->getLHS());
2154  else
2155    BaseV = EmitLValue(E->getLHS()).getAddress();
2156
2157  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
2158
2159  const MemberPointerType *MPT
2160    = E->getRHS()->getType()->getAs<MemberPointerType>();
2161
2162  llvm::Value *AddV =
2163    CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT);
2164
2165  return MakeAddrLValue(AddV, MPT->getPointeeType());
2166}
2167
2168