CGExpr.cpp revision d8af3601a5cddad7c6cf9a0e4a8563dcc6484664 
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 "CGObjCRuntime.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/DeclObjC.h"
20#include "llvm/Intrinsics.h"
21#include "clang/CodeGen/CodeGenOptions.h"
22#include "llvm/Target/TargetData.h"
23using namespace clang;
24using namespace CodeGen;
25
26//===--------------------------------------------------------------------===//
27//                        Miscellaneous Helper Methods
28//===--------------------------------------------------------------------===//
29
30/// CreateTempAlloca - This creates a alloca and inserts it into the entry
31/// block.
32llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
33                                                    const llvm::Twine &Name) {
34  if (!Builder.isNamePreserving())
35    return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
36  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
37}
38
39/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
40/// expression and compare the result against zero, returning an Int1Ty value.
41llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
42  QualType BoolTy = getContext().BoolTy;
43  if (E->getType()->isMemberFunctionPointerType()) {
44    llvm::Value *Ptr = CreateTempAlloca(ConvertType(E->getType()));
45    EmitAggExpr(E, Ptr, /*VolatileDest=*/false);
46
47    // Get the pointer.
48    llvm::Value *FuncPtr = Builder.CreateStructGEP(Ptr, 0, "src.ptr");
49    FuncPtr = Builder.CreateLoad(FuncPtr);
50
51    llvm::Value *IsNotNull =
52      Builder.CreateICmpNE(FuncPtr,
53                            llvm::Constant::getNullValue(FuncPtr->getType()),
54                            "tobool");
55
56    return IsNotNull;
57  }
58  if (!E->getType()->isAnyComplexType())
59    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
60
61  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
62}
63
64/// EmitAnyExpr - Emit code to compute the specified expression which can have
65/// any type.  The result is returned as an RValue struct.  If this is an
66/// aggregate expression, the aggloc/agglocvolatile arguments indicate where the
67/// result should be returned.
68RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc,
69                                    bool IsAggLocVolatile, bool IgnoreResult,
70                                    bool IsInitializer) {
71  if (!hasAggregateLLVMType(E->getType()))
72    return RValue::get(EmitScalarExpr(E, IgnoreResult));
73  else if (E->getType()->isAnyComplexType())
74    return RValue::getComplex(EmitComplexExpr(E, false, false,
75                                              IgnoreResult, IgnoreResult));
76
77  EmitAggExpr(E, AggLoc, IsAggLocVolatile, IgnoreResult, IsInitializer);
78  return RValue::getAggregate(AggLoc, IsAggLocVolatile);
79}
80
81/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
82/// always be accessible even if no aggregate location is provided.
83RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E,
84                                          bool IsAggLocVolatile,
85                                          bool IsInitializer) {
86  llvm::Value *AggLoc = 0;
87
88  if (hasAggregateLLVMType(E->getType()) &&
89      !E->getType()->isAnyComplexType())
90    AggLoc = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp");
91  return EmitAnyExpr(E, AggLoc, IsAggLocVolatile, /*IgnoreResult=*/false,
92                     IsInitializer);
93}
94
95RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
96                                                   QualType DestType,
97                                                   bool IsInitializer) {
98  bool ShouldDestroyTemporaries = false;
99  unsigned OldNumLiveTemporaries = 0;
100
101  if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
102    ShouldDestroyTemporaries = TE->shouldDestroyTemporaries();
103
104    // Keep track of the current cleanup stack depth.
105    if (ShouldDestroyTemporaries)
106      OldNumLiveTemporaries = LiveTemporaries.size();
107
108    E = TE->getSubExpr();
109  }
110
111  RValue Val;
112  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
113    // Emit the expr as an lvalue.
114    LValue LV = EmitLValue(E);
115    if (LV.isSimple())
116      return RValue::get(LV.getAddress());
117    Val = EmitLoadOfLValue(LV, E->getType());
118
119    if (ShouldDestroyTemporaries) {
120      // Pop temporaries.
121      while (LiveTemporaries.size() > OldNumLiveTemporaries)
122        PopCXXTemporary();
123    }
124  } else {
125    const CXXRecordDecl *BaseClassDecl = 0;
126    const CXXRecordDecl *DerivedClassDecl = 0;
127
128    if (const CastExpr *CE =
129          dyn_cast<CastExpr>(E->IgnoreParenNoopCasts(getContext()))) {
130      if (CE->getCastKind() == CastExpr::CK_DerivedToBase) {
131        E = CE->getSubExpr();
132
133        BaseClassDecl =
134          cast<CXXRecordDecl>(CE->getType()->getAs<RecordType>()->getDecl());
135        DerivedClassDecl =
136          cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
137      }
138    }
139
140    Val = EmitAnyExprToTemp(E, /*IsAggLocVolatile=*/false,
141                            IsInitializer);
142
143    if (ShouldDestroyTemporaries) {
144      // Pop temporaries.
145      while (LiveTemporaries.size() > OldNumLiveTemporaries)
146        PopCXXTemporary();
147    }
148
149    if (IsInitializer) {
150      // We might have to destroy the temporary variable.
151      if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
152        if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
153          if (!ClassDecl->hasTrivialDestructor()) {
154            const CXXDestructorDecl *Dtor =
155              ClassDecl->getDestructor(getContext());
156
157            {
158              DelayedCleanupBlock Scope(*this);
159              EmitCXXDestructorCall(Dtor, Dtor_Complete,
160                                    Val.getAggregateAddr());
161
162              // Make sure to jump to the exit block.
163              EmitBranch(Scope.getCleanupExitBlock());
164            }
165            if (Exceptions) {
166              EHCleanupBlock Cleanup(*this);
167              EmitCXXDestructorCall(Dtor, Dtor_Complete,
168                                    Val.getAggregateAddr());
169            }
170          }
171        }
172      }
173    }
174
175    // Check if need to perform the derived-to-base cast.
176    if (BaseClassDecl) {
177      llvm::Value *Derived = Val.getAggregateAddr();
178      llvm::Value *Base =
179        GetAddressOfBaseClass(Derived, DerivedClassDecl, BaseClassDecl,
180                              /*NullCheckValue=*/false);
181      return RValue::get(Base);
182    }
183  }
184
185  if (Val.isAggregate()) {
186    Val = RValue::get(Val.getAggregateAddr());
187  } else {
188    // Create a temporary variable that we can bind the reference to.
189    llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()),
190                                         "reftmp");
191    if (Val.isScalar())
192      EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
193    else
194      StoreComplexToAddr(Val.getComplexVal(), Temp, false);
195    Val = RValue::get(Temp);
196  }
197
198  return Val;
199}
200
201
202/// getAccessedFieldNo - Given an encoded value and a result number, return the
203/// input field number being accessed.
204unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
205                                             const llvm::Constant *Elts) {
206  if (isa<llvm::ConstantAggregateZero>(Elts))
207    return 0;
208
209  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
210}
211
212
213//===----------------------------------------------------------------------===//
214//                         LValue Expression Emission
215//===----------------------------------------------------------------------===//
216
217RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
218  if (Ty->isVoidType())
219    return RValue::get(0);
220
221  if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
222    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
223    llvm::Value *U = llvm::UndefValue::get(EltTy);
224    return RValue::getComplex(std::make_pair(U, U));
225  }
226
227  if (hasAggregateLLVMType(Ty)) {
228    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
229    return RValue::getAggregate(llvm::UndefValue::get(LTy));
230  }
231
232  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
233}
234
235RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
236                                              const char *Name) {
237  ErrorUnsupported(E, Name);
238  return GetUndefRValue(E->getType());
239}
240
241LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
242                                              const char *Name) {
243  ErrorUnsupported(E, Name);
244  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
245  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
246                          MakeQualifiers(E->getType()));
247}
248
249/// EmitLValue - Emit code to compute a designator that specifies the location
250/// of the expression.
251///
252/// This can return one of two things: a simple address or a bitfield reference.
253/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
254/// an LLVM pointer type.
255///
256/// If this returns a bitfield reference, nothing about the pointee type of the
257/// LLVM value is known: For example, it may not be a pointer to an integer.
258///
259/// If this returns a normal address, and if the lvalue's C type is fixed size,
260/// this method guarantees that the returned pointer type will point to an LLVM
261/// type of the same size of the lvalue's type.  If the lvalue has a variable
262/// length type, this is not possible.
263///
264LValue CodeGenFunction::EmitLValue(const Expr *E) {
265  switch (E->getStmtClass()) {
266  default: return EmitUnsupportedLValue(E, "l-value expression");
267
268  case Expr::ObjCIsaExprClass:
269    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
270  case Expr::BinaryOperatorClass:
271    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
272  case Expr::CallExprClass:
273  case Expr::CXXMemberCallExprClass:
274  case Expr::CXXOperatorCallExprClass:
275    return EmitCallExprLValue(cast<CallExpr>(E));
276  case Expr::VAArgExprClass:
277    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
278  case Expr::DeclRefExprClass:
279    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
280  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
281  case Expr::PredefinedExprClass:
282    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
283  case Expr::StringLiteralClass:
284    return EmitStringLiteralLValue(cast<StringLiteral>(E));
285  case Expr::ObjCEncodeExprClass:
286    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
287
288  case Expr::BlockDeclRefExprClass:
289    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
290
291  case Expr::CXXTemporaryObjectExprClass:
292  case Expr::CXXConstructExprClass:
293    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
294  case Expr::CXXBindTemporaryExprClass:
295    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
296  case Expr::CXXExprWithTemporariesClass:
297    return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
298  case Expr::CXXZeroInitValueExprClass:
299    return EmitNullInitializationLValue(cast<CXXZeroInitValueExpr>(E));
300  case Expr::CXXDefaultArgExprClass:
301    return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
302  case Expr::CXXTypeidExprClass:
303    return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
304
305  case Expr::ObjCMessageExprClass:
306    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
307  case Expr::ObjCIvarRefExprClass:
308    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
309  case Expr::ObjCPropertyRefExprClass:
310    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
311  case Expr::ObjCImplicitSetterGetterRefExprClass:
312    return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
313  case Expr::ObjCSuperExprClass:
314    return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
315
316  case Expr::StmtExprClass:
317    return EmitStmtExprLValue(cast<StmtExpr>(E));
318  case Expr::UnaryOperatorClass:
319    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
320  case Expr::ArraySubscriptExprClass:
321    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
322  case Expr::ExtVectorElementExprClass:
323    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
324  case Expr::MemberExprClass:
325    return EmitMemberExpr(cast<MemberExpr>(E));
326  case Expr::CompoundLiteralExprClass:
327    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
328  case Expr::ConditionalOperatorClass:
329    return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
330  case Expr::ChooseExprClass:
331    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
332  case Expr::ImplicitCastExprClass:
333  case Expr::CStyleCastExprClass:
334  case Expr::CXXFunctionalCastExprClass:
335  case Expr::CXXStaticCastExprClass:
336  case Expr::CXXDynamicCastExprClass:
337  case Expr::CXXReinterpretCastExprClass:
338  case Expr::CXXConstCastExprClass:
339    return EmitCastLValue(cast<CastExpr>(E));
340  }
341}
342
343llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
344                                               QualType Ty) {
345  llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
346  if (Volatile)
347    Load->setVolatile(true);
348
349  // Bool can have different representation in memory than in registers.
350  llvm::Value *V = Load;
351  if (Ty->isBooleanType())
352    if (V->getType() != llvm::Type::getInt1Ty(VMContext))
353      V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
354
355  return V;
356}
357
358void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
359                                        bool Volatile, QualType Ty) {
360
361  if (Ty->isBooleanType()) {
362    // Bool can have different representation in memory than in registers.
363    const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
364    Value = Builder.CreateIntCast(Value, DstPtr->getElementType(), false);
365  }
366  Builder.CreateStore(Value, Addr, Volatile);
367}
368
369/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
370/// method emits the address of the lvalue, then loads the result as an rvalue,
371/// returning the rvalue.
372RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
373  if (LV.isObjCWeak()) {
374    // load of a __weak object.
375    llvm::Value *AddrWeakObj = LV.getAddress();
376    return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
377                                                             AddrWeakObj));
378  }
379
380  if (LV.isSimple()) {
381    llvm::Value *Ptr = LV.getAddress();
382    const llvm::Type *EltTy =
383      cast<llvm::PointerType>(Ptr->getType())->getElementType();
384
385    // Simple scalar l-value.
386    if (EltTy->isSingleValueType())
387      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
388                                          ExprType));
389
390    assert(ExprType->isFunctionType() && "Unknown scalar value");
391    return RValue::get(Ptr);
392  }
393
394  if (LV.isVectorElt()) {
395    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
396                                          LV.isVolatileQualified(), "tmp");
397    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
398                                                    "vecext"));
399  }
400
401  // If this is a reference to a subset of the elements of a vector, either
402  // shuffle the input or extract/insert them as appropriate.
403  if (LV.isExtVectorElt())
404    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
405
406  if (LV.isBitfield())
407    return EmitLoadOfBitfieldLValue(LV, ExprType);
408
409  if (LV.isPropertyRef())
410    return EmitLoadOfPropertyRefLValue(LV, ExprType);
411
412  assert(LV.isKVCRef() && "Unknown LValue type!");
413  return EmitLoadOfKVCRefLValue(LV, ExprType);
414}
415
416RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
417                                                 QualType ExprType) {
418  unsigned StartBit = LV.getBitfieldStartBit();
419  unsigned BitfieldSize = LV.getBitfieldSize();
420  llvm::Value *Ptr = LV.getBitfieldAddr();
421
422  const llvm::Type *EltTy =
423    cast<llvm::PointerType>(Ptr->getType())->getElementType();
424  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
425
426  // In some cases the bitfield may straddle two memory locations.  Currently we
427  // load the entire bitfield, then do the magic to sign-extend it if
428  // necessary. This results in somewhat more code than necessary for the common
429  // case (one load), since two shifts accomplish both the masking and sign
430  // extension.
431  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
432  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp");
433
434  // Shift to proper location.
435  if (StartBit)
436    Val = Builder.CreateLShr(Val, StartBit, "bf.lo");
437
438  // Mask off unused bits.
439  llvm::Constant *LowMask = llvm::ConstantInt::get(VMContext,
440                                llvm::APInt::getLowBitsSet(EltTySize, LowBits));
441  Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared");
442
443  // Fetch the high bits if necessary.
444  if (LowBits < BitfieldSize) {
445    unsigned HighBits = BitfieldSize - LowBits;
446    llvm::Value *HighPtr = Builder.CreateGEP(Ptr, llvm::ConstantInt::get(
447                            llvm::Type::getInt32Ty(VMContext), 1), "bf.ptr.hi");
448    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
449                                              LV.isVolatileQualified(),
450                                              "tmp");
451
452    // Mask off unused bits.
453    llvm::Constant *HighMask = llvm::ConstantInt::get(VMContext,
454                               llvm::APInt::getLowBitsSet(EltTySize, HighBits));
455    HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared");
456
457    // Shift to proper location and or in to bitfield value.
458    HighVal = Builder.CreateShl(HighVal, LowBits);
459    Val = Builder.CreateOr(Val, HighVal, "bf.val");
460  }
461
462  // Sign extend if necessary.
463  if (LV.isBitfieldSigned()) {
464    llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy,
465                                                    EltTySize - BitfieldSize);
466    Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits),
467                             ExtraBits, "bf.val.sext");
468  }
469
470  // The bitfield type and the normal type differ when the storage sizes differ
471  // (currently just _Bool).
472  Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp");
473
474  return RValue::get(Val);
475}
476
477RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
478                                                    QualType ExprType) {
479  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
480}
481
482RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
483                                               QualType ExprType) {
484  return EmitObjCPropertyGet(LV.getKVCRefExpr());
485}
486
487// If this is a reference to a subset of the elements of a vector, create an
488// appropriate shufflevector.
489RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
490                                                         QualType ExprType) {
491  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
492                                        LV.isVolatileQualified(), "tmp");
493
494  const llvm::Constant *Elts = LV.getExtVectorElts();
495
496  // If the result of the expression is a non-vector type, we must be extracting
497  // a single element.  Just codegen as an extractelement.
498  const VectorType *ExprVT = ExprType->getAs<VectorType>();
499  if (!ExprVT) {
500    unsigned InIdx = getAccessedFieldNo(0, Elts);
501    llvm::Value *Elt = llvm::ConstantInt::get(
502                                      llvm::Type::getInt32Ty(VMContext), InIdx);
503    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
504  }
505
506  // Always use shuffle vector to try to retain the original program structure
507  unsigned NumResultElts = ExprVT->getNumElements();
508
509  llvm::SmallVector<llvm::Constant*, 4> Mask;
510  for (unsigned i = 0; i != NumResultElts; ++i) {
511    unsigned InIdx = getAccessedFieldNo(i, Elts);
512    Mask.push_back(llvm::ConstantInt::get(
513                                     llvm::Type::getInt32Ty(VMContext), InIdx));
514  }
515
516  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
517  Vec = Builder.CreateShuffleVector(Vec,
518                                    llvm::UndefValue::get(Vec->getType()),
519                                    MaskV, "tmp");
520  return RValue::get(Vec);
521}
522
523
524
525/// EmitStoreThroughLValue - Store the specified rvalue into the specified
526/// lvalue, where both are guaranteed to the have the same type, and that type
527/// is 'Ty'.
528void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
529                                             QualType Ty) {
530  if (!Dst.isSimple()) {
531    if (Dst.isVectorElt()) {
532      // Read/modify/write the vector, inserting the new element.
533      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
534                                            Dst.isVolatileQualified(), "tmp");
535      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
536                                        Dst.getVectorIdx(), "vecins");
537      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
538      return;
539    }
540
541    // If this is an update of extended vector elements, insert them as
542    // appropriate.
543    if (Dst.isExtVectorElt())
544      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
545
546    if (Dst.isBitfield())
547      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
548
549    if (Dst.isPropertyRef())
550      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
551
552    assert(Dst.isKVCRef() && "Unknown LValue type");
553    return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
554  }
555
556  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
557    // load of a __weak object.
558    llvm::Value *LvalueDst = Dst.getAddress();
559    llvm::Value *src = Src.getScalarVal();
560     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
561    return;
562  }
563
564  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
565    // load of a __strong object.
566    llvm::Value *LvalueDst = Dst.getAddress();
567    llvm::Value *src = Src.getScalarVal();
568    if (Dst.isObjCIvar()) {
569      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
570      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
571      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
572      llvm::Value *dst = RHS;
573      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
574      llvm::Value *LHS =
575        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
576      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
577      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
578                                              BytesBetween);
579    } else if (Dst.isGlobalObjCRef())
580      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
581    else
582      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
583    return;
584  }
585
586  assert(Src.isScalar() && "Can't emit an agg store with this method");
587  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
588                    Dst.isVolatileQualified(), Ty);
589}
590
591void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
592                                                     QualType Ty,
593                                                     llvm::Value **Result) {
594  unsigned StartBit = Dst.getBitfieldStartBit();
595  unsigned BitfieldSize = Dst.getBitfieldSize();
596  llvm::Value *Ptr = Dst.getBitfieldAddr();
597
598  const llvm::Type *EltTy =
599    cast<llvm::PointerType>(Ptr->getType())->getElementType();
600  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
601
602  // Get the new value, cast to the appropriate type and masked to exactly the
603  // size of the bit-field.
604  llvm::Value *SrcVal = Src.getScalarVal();
605  llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp");
606  llvm::Constant *Mask = llvm::ConstantInt::get(VMContext,
607                           llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize));
608  NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value");
609
610  // Return the new value of the bit-field, if requested.
611  if (Result) {
612    // Cast back to the proper type for result.
613    const llvm::Type *SrcTy = SrcVal->getType();
614    llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false,
615                                                  "bf.reload.val");
616
617    // Sign extend if necessary.
618    if (Dst.isBitfieldSigned()) {
619      unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy);
620      llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy,
621                                                      SrcTySize - BitfieldSize);
622      SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits),
623                                    ExtraBits, "bf.reload.sext");
624    }
625
626    *Result = SrcTrunc;
627  }
628
629  // In some cases the bitfield may straddle two memory locations.  Emit the low
630  // part first and check to see if the high needs to be done.
631  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
632  llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(),
633                                           "bf.prev.low");
634
635  // Compute the mask for zero-ing the low part of this bitfield.
636  llvm::Constant *InvMask =
637    llvm::ConstantInt::get(VMContext,
638             ~llvm::APInt::getBitsSet(EltTySize, StartBit, StartBit + LowBits));
639
640  // Compute the new low part as
641  //   LowVal = (LowVal & InvMask) | (NewVal << StartBit),
642  // with the shift of NewVal implicitly stripping the high bits.
643  llvm::Value *NewLowVal =
644    Builder.CreateShl(NewVal, StartBit, "bf.value.lo");
645  LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared");
646  LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo");
647
648  // Write back.
649  Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified());
650
651  // If the low part doesn't cover the bitfield emit a high part.
652  if (LowBits < BitfieldSize) {
653    unsigned HighBits = BitfieldSize - LowBits;
654    llvm::Value *HighPtr =  Builder.CreateGEP(Ptr, llvm::ConstantInt::get(
655                            llvm::Type::getInt32Ty(VMContext), 1), "bf.ptr.hi");
656    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
657                                              Dst.isVolatileQualified(),
658                                              "bf.prev.hi");
659
660    // Compute the mask for zero-ing the high part of this bitfield.
661    llvm::Constant *InvMask =
662      llvm::ConstantInt::get(VMContext, ~llvm::APInt::getLowBitsSet(EltTySize,
663                               HighBits));
664
665    // Compute the new high part as
666    //   HighVal = (HighVal & InvMask) | (NewVal lshr LowBits),
667    // where the high bits of NewVal have already been cleared and the
668    // shift stripping the low bits.
669    llvm::Value *NewHighVal =
670      Builder.CreateLShr(NewVal, LowBits, "bf.value.high");
671    HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared");
672    HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi");
673
674    // Write back.
675    Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified());
676  }
677}
678
679void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
680                                                        LValue Dst,
681                                                        QualType Ty) {
682  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
683}
684
685void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
686                                                   LValue Dst,
687                                                   QualType Ty) {
688  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
689}
690
691void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
692                                                               LValue Dst,
693                                                               QualType Ty) {
694  // This access turns into a read/modify/write of the vector.  Load the input
695  // value now.
696  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
697                                        Dst.isVolatileQualified(), "tmp");
698  const llvm::Constant *Elts = Dst.getExtVectorElts();
699
700  llvm::Value *SrcVal = Src.getScalarVal();
701
702  if (const VectorType *VTy = Ty->getAs<VectorType>()) {
703    unsigned NumSrcElts = VTy->getNumElements();
704    unsigned NumDstElts =
705       cast<llvm::VectorType>(Vec->getType())->getNumElements();
706    if (NumDstElts == NumSrcElts) {
707      // Use shuffle vector is the src and destination are the same number of
708      // elements and restore the vector mask since it is on the side it will be
709      // stored.
710      llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
711      for (unsigned i = 0; i != NumSrcElts; ++i) {
712        unsigned InIdx = getAccessedFieldNo(i, Elts);
713        Mask[InIdx] = llvm::ConstantInt::get(
714                                          llvm::Type::getInt32Ty(VMContext), i);
715      }
716
717      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
718      Vec = Builder.CreateShuffleVector(SrcVal,
719                                        llvm::UndefValue::get(Vec->getType()),
720                                        MaskV, "tmp");
721    } else if (NumDstElts > NumSrcElts) {
722      // Extended the source vector to the same length and then shuffle it
723      // into the destination.
724      // FIXME: since we're shuffling with undef, can we just use the indices
725      //        into that?  This could be simpler.
726      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
727      const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
728      unsigned i;
729      for (i = 0; i != NumSrcElts; ++i)
730        ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
731      for (; i != NumDstElts; ++i)
732        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
733      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
734                                                        ExtMask.size());
735      llvm::Value *ExtSrcVal =
736        Builder.CreateShuffleVector(SrcVal,
737                                    llvm::UndefValue::get(SrcVal->getType()),
738                                    ExtMaskV, "tmp");
739      // build identity
740      llvm::SmallVector<llvm::Constant*, 4> Mask;
741      for (unsigned i = 0; i != NumDstElts; ++i)
742        Mask.push_back(llvm::ConstantInt::get(Int32Ty, i));
743
744      // modify when what gets shuffled in
745      for (unsigned i = 0; i != NumSrcElts; ++i) {
746        unsigned Idx = getAccessedFieldNo(i, Elts);
747        Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts);
748      }
749      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
750      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
751    } else {
752      // We should never shorten the vector
753      assert(0 && "unexpected shorten vector length");
754    }
755  } else {
756    // If the Src is a scalar (not a vector) it must be updating one element.
757    unsigned InIdx = getAccessedFieldNo(0, Elts);
758    const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
759    llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
760    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
761  }
762
763  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
764}
765
766// setObjCGCLValueClass - sets class of he lvalue for the purpose of
767// generating write-barries API. It is currently a global, ivar,
768// or neither.
769static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
770                                 LValue &LV) {
771  if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
772    return;
773
774  if (isa<ObjCIvarRefExpr>(E)) {
775    LV.SetObjCIvar(LV, true);
776    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
777    LV.setBaseIvarExp(Exp->getBase());
778    LV.SetObjCArray(LV, E->getType()->isArrayType());
779    return;
780  }
781
782  if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
783    if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
784      if ((VD->isBlockVarDecl() && !VD->hasLocalStorage()) ||
785          VD->isFileVarDecl())
786        LV.SetGlobalObjCRef(LV, true);
787    }
788    LV.SetObjCArray(LV, E->getType()->isArrayType());
789    return;
790  }
791
792  if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
793    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
794    return;
795  }
796
797  if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
798    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
799    if (LV.isObjCIvar()) {
800      // If cast is to a structure pointer, follow gcc's behavior and make it
801      // a non-ivar write-barrier.
802      QualType ExpTy = E->getType();
803      if (ExpTy->isPointerType())
804        ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
805      if (ExpTy->isRecordType())
806        LV.SetObjCIvar(LV, false);
807    }
808    return;
809  }
810  if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
811    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
812    return;
813  }
814
815  if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
816    setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
817    return;
818  }
819
820  if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
821    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
822    if (LV.isObjCIvar() && !LV.isObjCArray())
823      // Using array syntax to assigning to what an ivar points to is not
824      // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
825      LV.SetObjCIvar(LV, false);
826    else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
827      // Using array syntax to assigning to what global points to is not
828      // same as assigning to the global itself. {id *G;} G[i] = 0;
829      LV.SetGlobalObjCRef(LV, false);
830    return;
831  }
832
833  if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
834    setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
835    // We don't know if member is an 'ivar', but this flag is looked at
836    // only in the context of LV.isObjCIvar().
837    LV.SetObjCArray(LV, E->getType()->isArrayType());
838    return;
839  }
840}
841
842static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
843                                      const Expr *E, const VarDecl *VD) {
844  assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
845         "Var decl must have external storage or be a file var decl!");
846
847  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
848  if (VD->getType()->isReferenceType())
849    V = CGF.Builder.CreateLoad(V, "tmp");
850  LValue LV = LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
851  setObjCGCLValueClass(CGF.getContext(), E, LV);
852  return LV;
853}
854
855static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
856                                      const Expr *E, const FunctionDecl *FD) {
857  llvm::Value* V = CGF.CGM.GetAddrOfFunction(FD);
858  if (!FD->hasPrototype()) {
859    if (const FunctionProtoType *Proto =
860            FD->getType()->getAs<FunctionProtoType>()) {
861      // Ugly case: for a K&R-style definition, the type of the definition
862      // isn't the same as the type of a use.  Correct for this with a
863      // bitcast.
864      QualType NoProtoType =
865          CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
866      NoProtoType = CGF.getContext().getPointerType(NoProtoType);
867      V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
868    }
869  }
870  return LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
871}
872
873LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
874  const NamedDecl *ND = E->getDecl();
875
876  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
877
878    // Check if this is a global variable.
879    if (VD->hasExternalStorage() || VD->isFileVarDecl())
880      return EmitGlobalVarDeclLValue(*this, E, VD);
881
882    bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
883
884    llvm::Value *V = LocalDeclMap[VD];
885    assert(V && "DeclRefExpr not entered in LocalDeclMap?");
886
887    Qualifiers Quals = MakeQualifiers(E->getType());
888    // local variables do not get their gc attribute set.
889    // local static?
890    if (NonGCable) Quals.removeObjCGCAttr();
891
892    if (VD->hasAttr<BlocksAttr>()) {
893      V = Builder.CreateStructGEP(V, 1, "forwarding");
894      V = Builder.CreateLoad(V);
895      V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
896                                  VD->getNameAsString());
897    }
898    if (VD->getType()->isReferenceType())
899      V = Builder.CreateLoad(V, "tmp");
900    LValue LV = LValue::MakeAddr(V, Quals);
901    LValue::SetObjCNonGC(LV, NonGCable);
902    setObjCGCLValueClass(getContext(), E, LV);
903    return LV;
904  }
905
906  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
907    return EmitFunctionDeclLValue(*this, E, FD);
908
909  if (E->getQualifier()) {
910    // FIXME: the qualifier check does not seem sufficient here
911    return EmitPointerToDataMemberLValue(cast<FieldDecl>(ND));
912  }
913
914  assert(false && "Unhandled DeclRefExpr");
915
916  // an invalid LValue, but the assert will
917  // ensure that this point is never reached.
918  return LValue();
919}
920
921LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
922  return LValue::MakeAddr(GetAddrOfBlockDecl(E), MakeQualifiers(E->getType()));
923}
924
925LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
926  // __extension__ doesn't affect lvalue-ness.
927  if (E->getOpcode() == UnaryOperator::Extension)
928    return EmitLValue(E->getSubExpr());
929
930  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
931  switch (E->getOpcode()) {
932  default: assert(0 && "Unknown unary operator lvalue!");
933  case UnaryOperator::Deref: {
934    QualType T = E->getSubExpr()->getType()->getPointeeType();
935    assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
936
937    Qualifiers Quals = MakeQualifiers(T);
938    Quals.setAddressSpace(ExprTy.getAddressSpace());
939
940    LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), Quals);
941    // We should not generate __weak write barrier on indirect reference
942    // of a pointer to object; as in void foo (__weak id *param); *param = 0;
943    // But, we continue to generate __strong write barrier on indirect write
944    // into a pointer to object.
945    if (getContext().getLangOptions().ObjC1 &&
946        getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
947        LV.isObjCWeak())
948      LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
949    return LV;
950  }
951  case UnaryOperator::Real:
952  case UnaryOperator::Imag: {
953    LValue LV = EmitLValue(E->getSubExpr());
954    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
955    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
956                                                    Idx, "idx"),
957                            MakeQualifiers(ExprTy));
958  }
959  case UnaryOperator::PreInc:
960  case UnaryOperator::PreDec:
961    return EmitUnsupportedLValue(E, "pre-inc/dec expression");
962  }
963}
964
965LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
966  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E),
967                          Qualifiers());
968}
969
970LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
971  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E),
972                          Qualifiers());
973}
974
975
976LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
977  std::string GlobalVarName;
978
979  switch (Type) {
980  default: assert(0 && "Invalid type");
981  case PredefinedExpr::Func:
982    GlobalVarName = "__func__.";
983    break;
984  case PredefinedExpr::Function:
985    GlobalVarName = "__FUNCTION__.";
986    break;
987  case PredefinedExpr::PrettyFunction:
988    GlobalVarName = "__PRETTY_FUNCTION__.";
989    break;
990  }
991
992  llvm::StringRef FnName = CurFn->getName();
993  if (FnName.startswith("\01"))
994    FnName = FnName.substr(1);
995  GlobalVarName += FnName;
996
997  std::string FunctionName =
998    PredefinedExpr::ComputeName(getContext(), (PredefinedExpr::IdentType)Type,
999                                CurCodeDecl);
1000
1001  llvm::Constant *C =
1002    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
1003  return LValue::MakeAddr(C, Qualifiers());
1004}
1005
1006LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
1007  switch (E->getIdentType()) {
1008  default:
1009    return EmitUnsupportedLValue(E, "predefined expression");
1010  case PredefinedExpr::Func:
1011  case PredefinedExpr::Function:
1012  case PredefinedExpr::PrettyFunction:
1013    return EmitPredefinedFunctionName(E->getIdentType());
1014  }
1015}
1016
1017llvm::BasicBlock *CodeGenFunction::getTrapBB() {
1018  const CodeGenOptions &GCO = CGM.getCodeGenOpts();
1019
1020  // If we are not optimzing, don't collapse all calls to trap in the function
1021  // to the same call, that way, in the debugger they can see which operation
1022  // did in fact fail.  If we are optimizing, we collpase all call to trap down
1023  // to just one per function to save on codesize.
1024  if (GCO.OptimizationLevel
1025      && TrapBB)
1026    return TrapBB;
1027
1028  llvm::BasicBlock *Cont = 0;
1029  if (HaveInsertPoint()) {
1030    Cont = createBasicBlock("cont");
1031    EmitBranch(Cont);
1032  }
1033  TrapBB = createBasicBlock("trap");
1034  EmitBlock(TrapBB);
1035
1036  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
1037  llvm::CallInst *TrapCall = Builder.CreateCall(F);
1038  TrapCall->setDoesNotReturn();
1039  TrapCall->setDoesNotThrow();
1040  Builder.CreateUnreachable();
1041
1042  if (Cont)
1043    EmitBlock(Cont);
1044  return TrapBB;
1045}
1046
1047LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1048  // The index must always be an integer, which is not an aggregate.  Emit it.
1049  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
1050  QualType IdxTy  = E->getIdx()->getType();
1051  bool IdxSigned = IdxTy->isSignedIntegerType();
1052
1053  // If the base is a vector type, then we are forming a vector element lvalue
1054  // with this subscript.
1055  if (E->getBase()->getType()->isVectorType()) {
1056    // Emit the vector as an lvalue to get its address.
1057    LValue LHS = EmitLValue(E->getBase());
1058    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
1059    Idx = Builder.CreateIntCast(Idx,
1060                          llvm::Type::getInt32Ty(VMContext), IdxSigned, "vidx");
1061    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
1062                                 E->getBase()->getType().getCVRQualifiers());
1063  }
1064
1065  // The base must be a pointer, which is not an aggregate.  Emit it.
1066  llvm::Value *Base = EmitScalarExpr(E->getBase());
1067
1068  // Extend or truncate the index type to 32 or 64-bits.
1069  unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
1070  if (IdxBitwidth != LLVMPointerWidth)
1071    Idx = Builder.CreateIntCast(Idx,
1072                            llvm::IntegerType::get(VMContext, LLVMPointerWidth),
1073                                IdxSigned, "idxprom");
1074
1075  if (CatchUndefined) {
1076    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())) {
1077      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1078        if (ICE->getCastKind() == CastExpr::CK_ArrayToPointerDecay) {
1079          if (const ConstantArrayType *CAT
1080              = getContext().getAsConstantArrayType(DRE->getType())) {
1081            llvm::APInt Size = CAT->getSize();
1082            llvm::BasicBlock *Cont = createBasicBlock("cont");
1083            Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
1084                                  llvm::ConstantInt::get(Idx->getType(), Size)),
1085                                 Cont, getTrapBB());
1086            EmitBlock(Cont);
1087          }
1088        }
1089      }
1090    }
1091  }
1092
1093  // We know that the pointer points to a type of the correct size, unless the
1094  // size is a VLA or Objective-C interface.
1095  llvm::Value *Address = 0;
1096  if (const VariableArrayType *VAT =
1097        getContext().getAsVariableArrayType(E->getType())) {
1098    llvm::Value *VLASize = GetVLASize(VAT);
1099
1100    Idx = Builder.CreateMul(Idx, VLASize);
1101
1102    QualType BaseType = getContext().getBaseElementType(VAT);
1103
1104    uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
1105    Idx = Builder.CreateUDiv(Idx,
1106                             llvm::ConstantInt::get(Idx->getType(),
1107                                                    BaseTypeSize));
1108    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1109  } else if (const ObjCInterfaceType *OIT =
1110             dyn_cast<ObjCInterfaceType>(E->getType())) {
1111    llvm::Value *InterfaceSize =
1112      llvm::ConstantInt::get(Idx->getType(),
1113                             getContext().getTypeSize(OIT) / 8);
1114
1115    Idx = Builder.CreateMul(Idx, InterfaceSize);
1116
1117    const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
1118    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
1119                                Idx, "arrayidx");
1120    Address = Builder.CreateBitCast(Address, Base->getType());
1121  } else {
1122    Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
1123  }
1124
1125  QualType T = E->getBase()->getType()->getPointeeType();
1126  assert(!T.isNull() &&
1127         "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
1128
1129  Qualifiers Quals = MakeQualifiers(T);
1130  Quals.setAddressSpace(E->getBase()->getType().getAddressSpace());
1131
1132  LValue LV = LValue::MakeAddr(Address, Quals);
1133  if (getContext().getLangOptions().ObjC1 &&
1134      getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
1135    LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
1136    setObjCGCLValueClass(getContext(), E, LV);
1137  }
1138  return LV;
1139}
1140
1141static
1142llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
1143                                       llvm::SmallVector<unsigned, 4> &Elts) {
1144  llvm::SmallVector<llvm::Constant *, 4> CElts;
1145
1146  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
1147    CElts.push_back(llvm::ConstantInt::get(
1148                                   llvm::Type::getInt32Ty(VMContext), Elts[i]));
1149
1150  return llvm::ConstantVector::get(&CElts[0], CElts.size());
1151}
1152
1153LValue CodeGenFunction::
1154EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
1155  // Emit the base vector as an l-value.
1156  LValue Base;
1157
1158  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
1159  if (!E->isArrow()) {
1160    assert(E->getBase()->getType()->isVectorType());
1161    Base = EmitLValue(E->getBase());
1162  } else {
1163    const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
1164    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
1165    Qualifiers Quals = MakeQualifiers(PT->getPointeeType());
1166    Quals.removeObjCGCAttr();
1167    Base = LValue::MakeAddr(Ptr, Quals);
1168  }
1169
1170  // Encode the element access list into a vector of unsigned indices.
1171  llvm::SmallVector<unsigned, 4> Indices;
1172  E->getEncodedElementAccess(Indices);
1173
1174  if (Base.isSimple()) {
1175    llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
1176    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
1177                                    Base.getVRQualifiers());
1178  }
1179  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
1180
1181  llvm::Constant *BaseElts = Base.getExtVectorElts();
1182  llvm::SmallVector<llvm::Constant *, 4> CElts;
1183
1184  const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
1185  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
1186    if (isa<llvm::ConstantAggregateZero>(BaseElts))
1187      CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
1188    else
1189      CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
1190  }
1191  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
1192  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
1193                                  Base.getVRQualifiers());
1194}
1195
1196LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
1197  bool isUnion = false;
1198  bool isNonGC = false;
1199  Expr *BaseExpr = E->getBase();
1200  llvm::Value *BaseValue = NULL;
1201  Qualifiers BaseQuals;
1202
1203  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
1204  if (E->isArrow()) {
1205    BaseValue = EmitScalarExpr(BaseExpr);
1206    const PointerType *PTy =
1207      BaseExpr->getType()->getAs<PointerType>();
1208    if (PTy->getPointeeType()->isUnionType())
1209      isUnion = true;
1210    BaseQuals = PTy->getPointeeType().getQualifiers();
1211  } else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
1212             isa<ObjCImplicitSetterGetterRefExpr>(
1213               BaseExpr->IgnoreParens())) {
1214    RValue RV = EmitObjCPropertyGet(BaseExpr);
1215    BaseValue = RV.getAggregateAddr();
1216    if (BaseExpr->getType()->isUnionType())
1217      isUnion = true;
1218    BaseQuals = BaseExpr->getType().getQualifiers();
1219  } else {
1220    LValue BaseLV = EmitLValue(BaseExpr);
1221    if (BaseLV.isNonGC())
1222      isNonGC = true;
1223    // FIXME: this isn't right for bitfields.
1224    BaseValue = BaseLV.getAddress();
1225    QualType BaseTy = BaseExpr->getType();
1226    if (BaseTy->isUnionType())
1227      isUnion = true;
1228    BaseQuals = BaseTy.getQualifiers();
1229  }
1230
1231  NamedDecl *ND = E->getMemberDecl();
1232  if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
1233    LValue LV = EmitLValueForField(BaseValue, Field, isUnion,
1234                                   BaseQuals.getCVRQualifiers());
1235    LValue::SetObjCNonGC(LV, isNonGC);
1236    setObjCGCLValueClass(getContext(), E, LV);
1237    return LV;
1238  }
1239
1240  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
1241    return EmitGlobalVarDeclLValue(*this, E, VD);
1242
1243  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
1244    return EmitFunctionDeclLValue(*this, E, FD);
1245
1246  assert(false && "Unhandled member declaration!");
1247  return LValue();
1248}
1249
1250LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
1251                                              const FieldDecl* Field,
1252                                              unsigned CVRQualifiers) {
1253  CodeGenTypes::BitFieldInfo Info = CGM.getTypes().getBitFieldInfo(Field);
1254
1255  // FIXME: CodeGenTypes should expose a method to get the appropriate type for
1256  // FieldTy (the appropriate type is ABI-dependent).
1257  const llvm::Type *FieldTy =
1258    CGM.getTypes().ConvertTypeForMem(Field->getType());
1259  const llvm::PointerType *BaseTy =
1260  cast<llvm::PointerType>(BaseValue->getType());
1261  unsigned AS = BaseTy->getAddressSpace();
1262  BaseValue = Builder.CreateBitCast(BaseValue,
1263                                    llvm::PointerType::get(FieldTy, AS),
1264                                    "tmp");
1265
1266  llvm::Value *Idx =
1267    llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Info.FieldNo);
1268  llvm::Value *V = Builder.CreateGEP(BaseValue, Idx, "tmp");
1269
1270  return LValue::MakeBitfield(V, Info.Start, Info.Size,
1271                              Field->getType()->isSignedIntegerType(),
1272                            Field->getType().getCVRQualifiers()|CVRQualifiers);
1273}
1274
1275LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
1276                                           const FieldDecl* Field,
1277                                           bool isUnion,
1278                                           unsigned CVRQualifiers) {
1279  if (Field->isBitField())
1280    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
1281
1282  unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
1283  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
1284
1285  // Match union field type.
1286  if (isUnion) {
1287    const llvm::Type *FieldTy =
1288      CGM.getTypes().ConvertTypeForMem(Field->getType());
1289    const llvm::PointerType * BaseTy =
1290      cast<llvm::PointerType>(BaseValue->getType());
1291    unsigned AS = BaseTy->getAddressSpace();
1292    V = Builder.CreateBitCast(V,
1293                              llvm::PointerType::get(FieldTy, AS),
1294                              "tmp");
1295  }
1296  if (Field->getType()->isReferenceType())
1297    V = Builder.CreateLoad(V, "tmp");
1298
1299  Qualifiers Quals = MakeQualifiers(Field->getType());
1300  Quals.addCVRQualifiers(CVRQualifiers);
1301  // __weak attribute on a field is ignored.
1302  if (Quals.getObjCGCAttr() == Qualifiers::Weak)
1303    Quals.removeObjCGCAttr();
1304
1305  return LValue::MakeAddr(V, Quals);
1306}
1307
1308LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
1309  const llvm::Type *LTy = ConvertType(E->getType());
1310  llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral");
1311
1312  const Expr* InitExpr = E->getInitializer();
1313  LValue Result = LValue::MakeAddr(DeclPtr, MakeQualifiers(E->getType()));
1314
1315  if (E->getType()->isComplexType())
1316    EmitComplexExprIntoAddr(InitExpr, DeclPtr, false);
1317  else if (hasAggregateLLVMType(E->getType()))
1318    EmitAnyExpr(InitExpr, DeclPtr, false);
1319  else
1320    EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType());
1321
1322  return Result;
1323}
1324
1325LValue
1326CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
1327  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
1328    llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
1329    llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
1330    llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
1331
1332    llvm::Value *Cond = EvaluateExprAsBool(E->getCond());
1333    Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
1334
1335    EmitBlock(LHSBlock);
1336
1337    LValue LHS = EmitLValue(E->getLHS());
1338    if (!LHS.isSimple())
1339      return EmitUnsupportedLValue(E, "conditional operator");
1340
1341    llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
1342    Builder.CreateStore(LHS.getAddress(), Temp);
1343    EmitBranch(ContBlock);
1344
1345    EmitBlock(RHSBlock);
1346    LValue RHS = EmitLValue(E->getRHS());
1347    if (!RHS.isSimple())
1348      return EmitUnsupportedLValue(E, "conditional operator");
1349
1350    Builder.CreateStore(RHS.getAddress(), Temp);
1351    EmitBranch(ContBlock);
1352
1353    EmitBlock(ContBlock);
1354
1355    Temp = Builder.CreateLoad(Temp, "lv");
1356    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1357  }
1358
1359  // ?: here should be an aggregate.
1360  assert((hasAggregateLLVMType(E->getType()) &&
1361          !E->getType()->isAnyComplexType()) &&
1362         "Unexpected conditional operator!");
1363
1364  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1365  EmitAggExpr(E, Temp, false);
1366
1367  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1368}
1369
1370/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
1371/// If the cast is a dynamic_cast, we can have the usual lvalue result,
1372/// otherwise if a cast is needed by the code generator in an lvalue context,
1373/// then it must mean that we need the address of an aggregate in order to
1374/// access one of its fields.  This can happen for all the reasons that casts
1375/// are permitted with aggregate result, including noop aggregate casts, and
1376/// cast from scalar to union.
1377LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
1378  switch (E->getCastKind()) {
1379  default:
1380    return EmitUnsupportedLValue(E, "unexpected cast lvalue");
1381
1382  case CastExpr::CK_Dynamic: {
1383    LValue LV = EmitLValue(E->getSubExpr());
1384    llvm::Value *V = LV.getAddress();
1385    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
1386    return LValue::MakeAddr(EmitDynamicCast(V, DCE),
1387                            MakeQualifiers(E->getType()));
1388  }
1389
1390  case CastExpr::CK_NoOp:
1391  case CastExpr::CK_ConstructorConversion:
1392  case CastExpr::CK_UserDefinedConversion:
1393    return EmitLValue(E->getSubExpr());
1394
1395  case CastExpr::CK_DerivedToBase: {
1396    const RecordType *DerivedClassTy =
1397      E->getSubExpr()->getType()->getAs<RecordType>();
1398    CXXRecordDecl *DerivedClassDecl =
1399      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1400
1401    const RecordType *BaseClassTy = E->getType()->getAs<RecordType>();
1402    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl());
1403
1404    LValue LV = EmitLValue(E->getSubExpr());
1405
1406    // Perform the derived-to-base conversion
1407    llvm::Value *Base =
1408      GetAddressOfBaseClass(LV.getAddress(), DerivedClassDecl,
1409                            BaseClassDecl, /*NullCheckValue=*/false);
1410
1411    return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
1412  }
1413  case CastExpr::CK_ToUnion: {
1414    llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1415    EmitAnyExpr(E->getSubExpr(), Temp, false);
1416
1417    return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1418  }
1419  case CastExpr::CK_BaseToDerived: {
1420    const RecordType *BaseClassTy =
1421      E->getSubExpr()->getType()->getAs<RecordType>();
1422    CXXRecordDecl *BaseClassDecl =
1423      cast<CXXRecordDecl>(BaseClassTy->getDecl());
1424
1425    const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
1426    CXXRecordDecl *DerivedClassDecl =
1427      cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1428
1429    LValue LV = EmitLValue(E->getSubExpr());
1430
1431    // Perform the base-to-derived conversion
1432    llvm::Value *Derived =
1433      GetAddressOfDerivedClass(LV.getAddress(), BaseClassDecl,
1434                               DerivedClassDecl, /*NullCheckValue=*/false);
1435
1436    return LValue::MakeAddr(Derived, MakeQualifiers(E->getType()));
1437  }
1438  case CastExpr::CK_BitCast: {
1439    // This must be a reinterpret_cast (or c-style equivalent).
1440    const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
1441
1442    LValue LV = EmitLValue(E->getSubExpr());
1443    llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
1444                                           ConvertType(CE->getTypeAsWritten()));
1445    return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
1446  }
1447  }
1448}
1449
1450LValue CodeGenFunction::EmitNullInitializationLValue(
1451                                              const CXXZeroInitValueExpr *E) {
1452  QualType Ty = E->getType();
1453  const llvm::Type *LTy = ConvertTypeForMem(Ty);
1454  llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
1455  unsigned Align = getContext().getTypeAlign(Ty)/8;
1456  Alloc->setAlignment(Align);
1457  LValue lvalue = LValue::MakeAddr(Alloc, Qualifiers());
1458  EmitMemSetToZero(lvalue.getAddress(), Ty);
1459  return lvalue;
1460}
1461
1462//===--------------------------------------------------------------------===//
1463//                             Expression Emission
1464//===--------------------------------------------------------------------===//
1465
1466
1467RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
1468  // Builtins never have block type.
1469  if (E->getCallee()->getType()->isBlockPointerType())
1470    return EmitBlockCallExpr(E);
1471
1472  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
1473    return EmitCXXMemberCallExpr(CE);
1474
1475  const Decl *TargetDecl = 0;
1476  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
1477    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
1478      TargetDecl = DRE->getDecl();
1479      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
1480        if (unsigned builtinID = FD->getBuiltinID())
1481          return EmitBuiltinExpr(FD, builtinID, E);
1482    }
1483  }
1484
1485  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
1486    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
1487      return EmitCXXOperatorMemberCallExpr(CE, MD);
1488
1489  if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
1490    // C++ [expr.pseudo]p1:
1491    //   The result shall only be used as the operand for the function call
1492    //   operator (), and the result of such a call has type void. The only
1493    //   effect is the evaluation of the postfix-expression before the dot or
1494    //   arrow.
1495    EmitScalarExpr(E->getCallee());
1496    return RValue::get(0);
1497  }
1498
1499  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
1500  return EmitCall(Callee, E->getCallee()->getType(),
1501                  E->arg_begin(), E->arg_end(), TargetDecl);
1502}
1503
1504LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
1505  // Comma expressions just emit their LHS then their RHS as an l-value.
1506  if (E->getOpcode() == BinaryOperator::Comma) {
1507    EmitAnyExpr(E->getLHS());
1508    EnsureInsertPoint();
1509    return EmitLValue(E->getRHS());
1510  }
1511
1512  if (E->getOpcode() == BinaryOperator::PtrMemD ||
1513      E->getOpcode() == BinaryOperator::PtrMemI)
1514    return EmitPointerToDataMemberBinaryExpr(E);
1515
1516  // Can only get l-value for binary operator expressions which are a
1517  // simple assignment of aggregate type.
1518  if (E->getOpcode() != BinaryOperator::Assign)
1519    return EmitUnsupportedLValue(E, "binary l-value expression");
1520
1521  if (!hasAggregateLLVMType(E->getType())) {
1522    // Emit the LHS as an l-value.
1523    LValue LV = EmitLValue(E->getLHS());
1524
1525    llvm::Value *RHS = EmitScalarExpr(E->getRHS());
1526    EmitStoreOfScalar(RHS, LV.getAddress(), LV.isVolatileQualified(),
1527                      E->getType());
1528    return LV;
1529  }
1530
1531  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1532  EmitAggExpr(E, Temp, false);
1533  // FIXME: Are these qualifiers correct?
1534  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1535}
1536
1537LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
1538  RValue RV = EmitCallExpr(E);
1539
1540  if (!RV.isScalar())
1541    return LValue::MakeAddr(RV.getAggregateAddr(),MakeQualifiers(E->getType()));
1542
1543  assert(E->getCallReturnType()->isReferenceType() &&
1544         "Can't have a scalar return unless the return type is a "
1545         "reference type!");
1546
1547  return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(E->getType()));
1548}
1549
1550LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
1551  // FIXME: This shouldn't require another copy.
1552  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1553  EmitAggExpr(E, Temp, false);
1554  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1555}
1556
1557LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
1558  llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), "tmp");
1559  EmitCXXConstructExpr(Temp, E);
1560  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1561}
1562
1563LValue
1564CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
1565  llvm::Value *Temp = EmitCXXTypeidExpr(E);
1566  return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
1567}
1568
1569LValue
1570CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
1571  LValue LV = EmitLValue(E->getSubExpr());
1572  PushCXXTemporary(E->getTemporary(), LV.getAddress());
1573  return LV;
1574}
1575
1576LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
1577  // Can only get l-value for message expression returning aggregate type
1578  RValue RV = EmitObjCMessageExpr(E);
1579  // FIXME: can this be volatile?
1580  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1581}
1582
1583llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
1584                                             const ObjCIvarDecl *Ivar) {
1585  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
1586}
1587
1588LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
1589                                          llvm::Value *BaseValue,
1590                                          const ObjCIvarDecl *Ivar,
1591                                          unsigned CVRQualifiers) {
1592  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
1593                                                   Ivar, CVRQualifiers);
1594}
1595
1596LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
1597  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
1598  llvm::Value *BaseValue = 0;
1599  const Expr *BaseExpr = E->getBase();
1600  Qualifiers BaseQuals;
1601  QualType ObjectTy;
1602  if (E->isArrow()) {
1603    BaseValue = EmitScalarExpr(BaseExpr);
1604    ObjectTy = BaseExpr->getType()->getPointeeType();
1605    BaseQuals = ObjectTy.getQualifiers();
1606  } else {
1607    LValue BaseLV = EmitLValue(BaseExpr);
1608    // FIXME: this isn't right for bitfields.
1609    BaseValue = BaseLV.getAddress();
1610    ObjectTy = BaseExpr->getType();
1611    BaseQuals = ObjectTy.getQualifiers();
1612  }
1613
1614  LValue LV =
1615    EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
1616                      BaseQuals.getCVRQualifiers());
1617  setObjCGCLValueClass(getContext(), E, LV);
1618  return LV;
1619}
1620
1621LValue
1622CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
1623  // This is a special l-value that just issues sends when we load or store
1624  // through it.
1625  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
1626}
1627
1628LValue CodeGenFunction::EmitObjCKVCRefLValue(
1629                                const ObjCImplicitSetterGetterRefExpr *E) {
1630  // This is a special l-value that just issues sends when we load or store
1631  // through it.
1632  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
1633}
1634
1635LValue CodeGenFunction::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
1636  return EmitUnsupportedLValue(E, "use of super");
1637}
1638
1639LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
1640  // Can only get l-value for message expression returning aggregate type
1641  RValue RV = EmitAnyExprToTemp(E);
1642  // FIXME: can this be volatile?
1643  return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
1644}
1645
1646
1647LValue CodeGenFunction::EmitPointerToDataMemberLValue(const FieldDecl *Field) {
1648  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Field->getDeclContext());
1649  QualType NNSpecTy =
1650    getContext().getCanonicalType(
1651      getContext().getTypeDeclType(const_cast<CXXRecordDecl*>(ClassDecl)));
1652  NNSpecTy = getContext().getPointerType(NNSpecTy);
1653  llvm::Value *V = llvm::Constant::getNullValue(ConvertType(NNSpecTy));
1654  LValue MemExpLV = EmitLValueForField(V, Field, /*isUnion=*/false,
1655                                       /*Qualifiers=*/0);
1656  const llvm::Type *ResultType = ConvertType(getContext().getPointerDiffType());
1657  V = Builder.CreatePtrToInt(MemExpLV.getAddress(), ResultType, "datamember");
1658  return LValue::MakeAddr(V, MakeQualifiers(Field->getType()));
1659}
1660
1661RValue CodeGenFunction::EmitCall(llvm::Value *Callee, QualType CalleeType,
1662                                 CallExpr::const_arg_iterator ArgBeg,
1663                                 CallExpr::const_arg_iterator ArgEnd,
1664                                 const Decl *TargetDecl) {
1665  // Get the actual function type. The callee type will always be a pointer to
1666  // function type or a block pointer type.
1667  assert(CalleeType->isFunctionPointerType() &&
1668         "Call must have function pointer type!");
1669
1670  CalleeType = getContext().getCanonicalType(CalleeType);
1671
1672  QualType FnType = cast<PointerType>(CalleeType)->getPointeeType();
1673  QualType ResultType = cast<FunctionType>(FnType)->getResultType();
1674
1675  CallArgList Args;
1676  EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
1677
1678  // FIXME: We should not need to do this, it should be part of the function
1679  // type.
1680  unsigned CallingConvention = 0;
1681  if (const llvm::Function *F =
1682      dyn_cast<llvm::Function>(Callee->stripPointerCasts()))
1683    CallingConvention = F->getCallingConv();
1684  return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args,
1685                                                 CallingConvention),
1686                  Callee, Args, TargetDecl);
1687}
1688
1689LValue CodeGenFunction::
1690EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
1691  llvm::Value *BaseV;
1692  if (E->getOpcode() == BinaryOperator::PtrMemI)
1693    BaseV = EmitScalarExpr(E->getLHS());
1694  else
1695    BaseV = EmitLValue(E->getLHS()).getAddress();
1696  const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
1697  BaseV = Builder.CreateBitCast(BaseV, i8Ty);
1698  llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
1699  llvm::Value *AddV = Builder.CreateInBoundsGEP(BaseV, OffsetV, "add.ptr");
1700
1701  QualType Ty = E->getRHS()->getType();
1702  Ty = Ty->getAs<MemberPointerType>()->getPointeeType();
1703
1704  const llvm::Type *PType = ConvertType(getContext().getPointerType(Ty));
1705  AddV = Builder.CreateBitCast(AddV, PType);
1706  return LValue::MakeAddr(AddV, MakeQualifiers(Ty));
1707}
1708
1709