CGExpr.cpp revision 6ec3668a2608b63473207319f5ceff9bbd22ea51 
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/Target/TargetData.h"
21using namespace clang;
22using namespace CodeGen;
23
24//===--------------------------------------------------------------------===//
25//                        Miscellaneous Helper Methods
26//===--------------------------------------------------------------------===//
27
28/// CreateTempAlloca - This creates a alloca and inserts it into the entry
29/// block.
30llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
31                                                    const char *Name) {
32  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
33}
34
35/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
36/// expression and compare the result against zero, returning an Int1Ty value.
37llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
38  QualType BoolTy = getContext().BoolTy;
39  if (!E->getType()->isAnyComplexType())
40    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
41
42  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
43}
44
45/// EmitAnyExpr - Emit code to compute the specified expression which can have
46/// any type.  The result is returned as an RValue struct.  If this is an
47/// aggregate expression, the aggloc/agglocvolatile arguments indicate where
48/// the result should be returned.
49RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc,
50                                    bool isAggLocVolatile) {
51  if (!hasAggregateLLVMType(E->getType()))
52    return RValue::get(EmitScalarExpr(E));
53  else if (E->getType()->isAnyComplexType())
54    return RValue::getComplex(EmitComplexExpr(E));
55
56  EmitAggExpr(E, AggLoc, isAggLocVolatile);
57  return RValue::getAggregate(AggLoc);
58}
59
60/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result
61/// will always be accessible even if no aggregate location is
62/// provided.
63RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E, llvm::Value *AggLoc,
64                                          bool isAggLocVolatile) {
65  if (!AggLoc && hasAggregateLLVMType(E->getType()) &&
66      !E->getType()->isAnyComplexType())
67    AggLoc = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp");
68  return EmitAnyExpr(E, AggLoc, isAggLocVolatile);
69}
70
71/// getAccessedFieldNo - Given an encoded value and a result number, return
72/// the input field number being accessed.
73unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
74                                             const llvm::Constant *Elts) {
75  if (isa<llvm::ConstantAggregateZero>(Elts))
76    return 0;
77
78  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
79}
80
81
82//===----------------------------------------------------------------------===//
83//                         LValue Expression Emission
84//===----------------------------------------------------------------------===//
85
86RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
87  if (Ty->isVoidType()) {
88    return RValue::get(0);
89  } else if (const ComplexType *CTy = Ty->getAsComplexType()) {
90    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
91    llvm::Value *U = llvm::UndefValue::get(EltTy);
92    return RValue::getComplex(std::make_pair(U, U));
93  } else if (hasAggregateLLVMType(Ty)) {
94    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
95    return RValue::getAggregate(llvm::UndefValue::get(LTy));
96  } else {
97    return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
98  }
99}
100
101RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
102                                              const char *Name) {
103  ErrorUnsupported(E, Name);
104  return GetUndefRValue(E->getType());
105}
106
107LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
108                                              const char *Name) {
109  ErrorUnsupported(E, Name);
110  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
111  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
112                          E->getType().getCVRQualifiers());
113}
114
115/// EmitLValue - Emit code to compute a designator that specifies the location
116/// of the expression.
117///
118/// This can return one of two things: a simple address or a bitfield
119/// reference.  In either case, the LLVM Value* in the LValue structure is
120/// guaranteed to be an LLVM pointer type.
121///
122/// If this returns a bitfield reference, nothing about the pointee type of
123/// the LLVM value is known: For example, it may not be a pointer to an
124/// integer.
125///
126/// If this returns a normal address, and if the lvalue's C type is fixed
127/// size, this method guarantees that the returned pointer type will point to
128/// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
129/// variable length type, this is not possible.
130///
131LValue CodeGenFunction::EmitLValue(const Expr *E) {
132  switch (E->getStmtClass()) {
133  default: return EmitUnsupportedLValue(E, "l-value expression");
134
135  case Expr::BinaryOperatorClass:
136    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
137  case Expr::CallExprClass:
138  case Expr::CXXOperatorCallExprClass:
139    return EmitCallExprLValue(cast<CallExpr>(E));
140  case Expr::VAArgExprClass:
141    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
142  case Expr::DeclRefExprClass:
143  case Expr::QualifiedDeclRefExprClass:
144    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
145  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
146  case Expr::PredefinedExprClass:
147    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
148  case Expr::StringLiteralClass:
149    return EmitStringLiteralLValue(cast<StringLiteral>(E));
150
151  case Expr::CXXConditionDeclExprClass:
152    return EmitCXXConditionDeclLValue(cast<CXXConditionDeclExpr>(E));
153
154  case Expr::ObjCMessageExprClass:
155    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
156  case Expr::ObjCIvarRefExprClass:
157    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
158  case Expr::ObjCPropertyRefExprClass:
159    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
160  case Expr::ObjCKVCRefExprClass:
161    return EmitObjCKVCRefLValue(cast<ObjCKVCRefExpr>(E));
162  case Expr::ObjCSuperExprClass:
163    return EmitObjCSuperExpr(cast<ObjCSuperExpr>(E));
164
165  case Expr::UnaryOperatorClass:
166    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
167  case Expr::ArraySubscriptExprClass:
168    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
169  case Expr::ExtVectorElementExprClass:
170    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
171  case Expr::MemberExprClass: return EmitMemberExpr(cast<MemberExpr>(E));
172  case Expr::CompoundLiteralExprClass:
173    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
174  case Expr::ChooseExprClass:
175    // __builtin_choose_expr is the lvalue of the selected operand.
176    if (cast<ChooseExpr>(E)->isConditionTrue(getContext()))
177      return EmitLValue(cast<ChooseExpr>(E)->getLHS());
178    else
179      return EmitLValue(cast<ChooseExpr>(E)->getRHS());
180  }
181}
182
183llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
184                                               QualType Ty) {
185  llvm::Value *V = Builder.CreateLoad(Addr, Volatile, "tmp");
186
187  // Bool can have different representation in memory than in
188  // registers.
189  if (Ty->isBooleanType())
190    if (V->getType() != llvm::Type::Int1Ty)
191      V = Builder.CreateTrunc(V, llvm::Type::Int1Ty, "tobool");
192
193  return V;
194}
195
196void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
197                                        bool Volatile) {
198  // Handle stores of types which have different representations in
199  // memory and as LLVM values.
200
201  // FIXME: We shouldn't be this loose, we should only do this
202  // conversion when we have a type we know has a different memory
203  // representation (e.g., bool).
204
205  const llvm::Type *SrcTy = Value->getType();
206  const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
207  if (DstPtr->getElementType() != SrcTy) {
208    const llvm::Type *MemTy =
209      llvm::PointerType::get(SrcTy, DstPtr->getAddressSpace());
210    Addr = Builder.CreateBitCast(Addr, MemTy, "storetmp");
211  }
212
213  Builder.CreateStore(Value, Addr, Volatile);
214}
215
216/// EmitLoadOfLValue - Given an expression that represents a value lvalue,
217/// this method emits the address of the lvalue, then loads the result as an
218/// rvalue, returning the rvalue.
219RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
220  if (LV.isObjCWeak()) {
221    // load of a __weak object.
222    llvm::Value *AddrWeakObj = LV.getAddress();
223    llvm::Value *read_weak = CGM.getObjCRuntime().EmitObjCWeakRead(*this,
224                                                                   AddrWeakObj);
225    return RValue::get(read_weak);
226  }
227
228  if (LV.isSimple()) {
229    llvm::Value *Ptr = LV.getAddress();
230    const llvm::Type *EltTy =
231      cast<llvm::PointerType>(Ptr->getType())->getElementType();
232
233    // Simple scalar l-value.
234    if (EltTy->isSingleValueType())
235      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
236                                          ExprType));
237
238    assert(ExprType->isFunctionType() && "Unknown scalar value");
239    return RValue::get(Ptr);
240  }
241
242  if (LV.isVectorElt()) {
243    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
244                                          LV.isVolatileQualified(), "tmp");
245    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
246                                                    "vecext"));
247  }
248
249  // If this is a reference to a subset of the elements of a vector, either
250  // shuffle the input or extract/insert them as appropriate.
251  if (LV.isExtVectorElt())
252    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
253
254  if (LV.isBitfield())
255    return EmitLoadOfBitfieldLValue(LV, ExprType);
256
257  if (LV.isPropertyRef())
258    return EmitLoadOfPropertyRefLValue(LV, ExprType);
259
260  assert(LV.isKVCRef() && "Unknown LValue type!");
261  return EmitLoadOfKVCRefLValue(LV, ExprType);
262}
263
264RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
265                                                 QualType ExprType) {
266  unsigned StartBit = LV.getBitfieldStartBit();
267  unsigned BitfieldSize = LV.getBitfieldSize();
268  llvm::Value *Ptr = LV.getBitfieldAddr();
269
270  const llvm::Type *EltTy =
271    cast<llvm::PointerType>(Ptr->getType())->getElementType();
272  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
273
274  // In some cases the bitfield may straddle two memory locations.
275  // Currently we load the entire bitfield, then do the magic to
276  // sign-extend it if necessary. This results in somewhat more code
277  // than necessary for the common case (one load), since two shifts
278  // accomplish both the masking and sign extension.
279  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
280  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp");
281
282  // Shift to proper location.
283  if (StartBit)
284    Val = Builder.CreateLShr(Val, llvm::ConstantInt::get(EltTy, StartBit),
285                             "bf.lo");
286
287  // Mask off unused bits.
288  llvm::Constant *LowMask =
289    llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, LowBits));
290  Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared");
291
292  // Fetch the high bits if necessary.
293  if (LowBits < BitfieldSize) {
294    unsigned HighBits = BitfieldSize - LowBits;
295    llvm::Value *HighPtr =
296      Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1),
297                        "bf.ptr.hi");
298    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
299                                              LV.isVolatileQualified(),
300                                              "tmp");
301
302    // Mask off unused bits.
303    llvm::Constant *HighMask =
304      llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, HighBits));
305    HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared");
306
307    // Shift to proper location and or in to bitfield value.
308    HighVal = Builder.CreateShl(HighVal,
309                                llvm::ConstantInt::get(EltTy, LowBits));
310    Val = Builder.CreateOr(Val, HighVal, "bf.val");
311  }
312
313  // Sign extend if necessary.
314  if (LV.isBitfieldSigned()) {
315    llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy,
316                                                    EltTySize - BitfieldSize);
317    Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits),
318                             ExtraBits, "bf.val.sext");
319  }
320
321  // The bitfield type and the normal type differ when the storage sizes
322  // differ (currently just _Bool).
323  Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp");
324
325  return RValue::get(Val);
326}
327
328RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
329                                                    QualType ExprType) {
330  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
331}
332
333RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
334                                               QualType ExprType) {
335  return EmitObjCPropertyGet(LV.getKVCRefExpr());
336}
337
338// If this is a reference to a subset of the elements of a vector, create an
339// appropriate shufflevector.
340RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
341                                                         QualType ExprType) {
342  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
343                                        LV.isVolatileQualified(), "tmp");
344
345  const llvm::Constant *Elts = LV.getExtVectorElts();
346
347  // If the result of the expression is a non-vector type, we must be
348  // extracting a single element.  Just codegen as an extractelement.
349  const VectorType *ExprVT = ExprType->getAsVectorType();
350  if (!ExprVT) {
351    unsigned InIdx = getAccessedFieldNo(0, Elts);
352    llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx);
353    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
354  }
355
356  // Always use shuffle vector to try to retain the original program structure
357  unsigned NumResultElts = ExprVT->getNumElements();
358
359  llvm::SmallVector<llvm::Constant*, 4> Mask;
360  for (unsigned i = 0; i != NumResultElts; ++i) {
361    unsigned InIdx = getAccessedFieldNo(i, Elts);
362    Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx));
363  }
364
365  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
366  Vec = Builder.CreateShuffleVector(Vec,
367                                    llvm::UndefValue::get(Vec->getType()),
368                                    MaskV, "tmp");
369  return RValue::get(Vec);
370}
371
372
373
374/// EmitStoreThroughLValue - Store the specified rvalue into the specified
375/// lvalue, where both are guaranteed to the have the same type, and that type
376/// is 'Ty'.
377void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
378                                             QualType Ty) {
379  if (!Dst.isSimple()) {
380    if (Dst.isVectorElt()) {
381      // Read/modify/write the vector, inserting the new element.
382      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
383                                            Dst.isVolatileQualified(), "tmp");
384      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
385                                        Dst.getVectorIdx(), "vecins");
386      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
387      return;
388    }
389
390    // If this is an update of extended vector elements, insert them as
391    // appropriate.
392    if (Dst.isExtVectorElt())
393      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
394
395    if (Dst.isBitfield())
396      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
397
398    if (Dst.isPropertyRef())
399      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
400
401    if (Dst.isKVCRef())
402      return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
403
404    assert(0 && "Unknown LValue type");
405  }
406
407  if (Dst.isObjCWeak()) {
408    // load of a __weak object.
409    llvm::Value *LvalueDst = Dst.getAddress();
410    llvm::Value *src = Src.getScalarVal();
411    CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
412    return;
413  }
414
415  if (Dst.isObjCStrong()) {
416    // load of a __strong object.
417    llvm::Value *LvalueDst = Dst.getAddress();
418    llvm::Value *src = Src.getScalarVal();
419    if (Dst.isObjCIvar())
420      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, LvalueDst);
421    else
422      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
423    return;
424  }
425
426  assert(Src.isScalar() && "Can't emit an agg store with this method");
427  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
428                    Dst.isVolatileQualified());
429}
430
431void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
432                                                     QualType Ty,
433                                                     llvm::Value **Result) {
434  unsigned StartBit = Dst.getBitfieldStartBit();
435  unsigned BitfieldSize = Dst.getBitfieldSize();
436  llvm::Value *Ptr = Dst.getBitfieldAddr();
437
438  const llvm::Type *EltTy =
439    cast<llvm::PointerType>(Ptr->getType())->getElementType();
440  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
441
442  // Get the new value, cast to the appropriate type and masked to
443  // exactly the size of the bit-field.
444  llvm::Value *SrcVal = Src.getScalarVal();
445  llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp");
446  llvm::Constant *Mask =
447    llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize));
448  NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value");
449
450  // Return the new value of the bit-field, if requested.
451  if (Result) {
452    // Cast back to the proper type for result.
453    const llvm::Type *SrcTy = SrcVal->getType();
454    llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false,
455                                                  "bf.reload.val");
456
457    // Sign extend if necessary.
458    if (Dst.isBitfieldSigned()) {
459      unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy);
460      llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy,
461                                                      SrcTySize - BitfieldSize);
462      SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits),
463                                    ExtraBits, "bf.reload.sext");
464    }
465
466    *Result = SrcTrunc;
467  }
468
469  // In some cases the bitfield may straddle two memory locations.
470  // Emit the low part first and check to see if the high needs to be
471  // done.
472  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
473  llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(),
474                                           "bf.prev.low");
475
476  // Compute the mask for zero-ing the low part of this bitfield.
477  llvm::Constant *InvMask =
478    llvm::ConstantInt::get(~llvm::APInt::getBitsSet(EltTySize, StartBit,
479                                                    StartBit + LowBits));
480
481  // Compute the new low part as
482  //   LowVal = (LowVal & InvMask) | (NewVal << StartBit),
483  // with the shift of NewVal implicitly stripping the high bits.
484  llvm::Value *NewLowVal =
485    Builder.CreateShl(NewVal, llvm::ConstantInt::get(EltTy, StartBit),
486                      "bf.value.lo");
487  LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared");
488  LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo");
489
490  // Write back.
491  Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified());
492
493  // If the low part doesn't cover the bitfield emit a high part.
494  if (LowBits < BitfieldSize) {
495    unsigned HighBits = BitfieldSize - LowBits;
496    llvm::Value *HighPtr =
497      Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1),
498                        "bf.ptr.hi");
499    llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
500                                              Dst.isVolatileQualified(),
501                                              "bf.prev.hi");
502
503    // Compute the mask for zero-ing the high part of this bitfield.
504    llvm::Constant *InvMask =
505      llvm::ConstantInt::get(~llvm::APInt::getLowBitsSet(EltTySize, HighBits));
506
507    // Compute the new high part as
508    //   HighVal = (HighVal & InvMask) | (NewVal lshr LowBits),
509    // where the high bits of NewVal have already been cleared and the
510    // shift stripping the low bits.
511    llvm::Value *NewHighVal =
512      Builder.CreateLShr(NewVal, llvm::ConstantInt::get(EltTy, LowBits),
513                        "bf.value.high");
514    HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared");
515    HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi");
516
517    // Write back.
518    Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified());
519  }
520}
521
522void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
523                                                        LValue Dst,
524                                                        QualType Ty) {
525  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
526}
527
528void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
529                                                   LValue Dst,
530                                                   QualType Ty) {
531  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
532}
533
534void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
535                                                               LValue Dst,
536                                                               QualType Ty) {
537  // This access turns into a read/modify/write of the vector.  Load the input
538  // value now.
539  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
540                                        Dst.isVolatileQualified(), "tmp");
541  const llvm::Constant *Elts = Dst.getExtVectorElts();
542
543  llvm::Value *SrcVal = Src.getScalarVal();
544
545  if (const VectorType *VTy = Ty->getAsVectorType()) {
546    unsigned NumSrcElts = VTy->getNumElements();
547    unsigned NumDstElts =
548       cast<llvm::VectorType>(Vec->getType())->getNumElements();
549    if (NumDstElts == NumSrcElts) {
550      // Use shuffle vector is the src and destination are the same number
551      // of elements
552      llvm::SmallVector<llvm::Constant*, 4> Mask;
553      for (unsigned i = 0; i != NumSrcElts; ++i) {
554        unsigned InIdx = getAccessedFieldNo(i, Elts);
555        Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx));
556      }
557
558      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
559      Vec = Builder.CreateShuffleVector(SrcVal,
560                                        llvm::UndefValue::get(Vec->getType()),
561                                        MaskV, "tmp");
562    }
563    else if (NumDstElts > NumSrcElts) {
564      // Extended the source vector to the same length and then shuffle it
565      // into the destination.
566      // FIXME: since we're shuffling with undef, can we just use the indices
567      //        into that?  This could be simpler.
568      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
569      unsigned i;
570      for (i = 0; i != NumSrcElts; ++i)
571        ExtMask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i));
572      for (; i != NumDstElts; ++i)
573        ExtMask.push_back(llvm::UndefValue::get(llvm::Type::Int32Ty));
574      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
575                                                        ExtMask.size());
576      llvm::Value *ExtSrcVal =
577        Builder.CreateShuffleVector(SrcVal,
578                                    llvm::UndefValue::get(SrcVal->getType()),
579                                    ExtMaskV, "tmp");
580      // build identity
581      llvm::SmallVector<llvm::Constant*, 4> Mask;
582      for (unsigned i = 0; i != NumDstElts; ++i) {
583        Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i));
584      }
585      // modify when what gets shuffled in
586      for (unsigned i = 0; i != NumSrcElts; ++i) {
587        unsigned Idx = getAccessedFieldNo(i, Elts);
588        Mask[Idx] =llvm::ConstantInt::get(llvm::Type::Int32Ty, i+NumDstElts);
589      }
590      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
591      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
592    }
593    else {
594      // We should never shorten the vector
595      assert(0 && "unexpected shorten vector length");
596    }
597  } else {
598    // If the Src is a scalar (not a vector) it must be updating one element.
599    unsigned InIdx = getAccessedFieldNo(0, Elts);
600    llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx);
601    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
602  }
603
604  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
605}
606
607/// SetDeclObjCGCAttrInLvalue - Set __weak/__strong attributes into the LValue
608/// object.
609static void SetDeclObjCGCAttrInLvalue(ASTContext &Ctx, const QualType &Ty,
610                                      LValue &LV)
611{
612  QualType::GCAttrTypes attr = Ctx.getObjCGCAttrKind(Ty);
613  if (attr != QualType::GCNone)
614    LValue::SetObjCType(attr == QualType::Weak,
615                        attr == QualType::Strong, LV);
616}
617
618LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
619  const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
620
621  if (VD && (VD->isBlockVarDecl() || isa<ParmVarDecl>(VD) ||
622        isa<ImplicitParamDecl>(VD))) {
623    LValue LV;
624    if (VD->getStorageClass() == VarDecl::Extern) {
625      LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD),
626                            E->getType().getCVRQualifiers());
627    }
628    else {
629      llvm::Value *V = LocalDeclMap[VD];
630      assert(V && "BlockVarDecl not entered in LocalDeclMap?");
631      LV = LValue::MakeAddr(V, E->getType().getCVRQualifiers());
632    }
633    if (VD->isBlockVarDecl() &&
634        (VD->getStorageClass() == VarDecl::Static ||
635         VD->getStorageClass() == VarDecl::Extern))
636      SetDeclObjCGCAttrInLvalue(getContext(), E->getType(), LV);
637    return LV;
638  } else if (VD && VD->isFileVarDecl()) {
639    LValue LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD),
640                                 E->getType().getCVRQualifiers());
641    SetDeclObjCGCAttrInLvalue(getContext(), E->getType(), LV);
642    return LV;
643  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl())) {
644    return LValue::MakeAddr(CGM.GetAddrOfFunction(FD),
645                            E->getType().getCVRQualifiers());
646  }
647  else if (const ImplicitParamDecl *IPD =
648      dyn_cast<ImplicitParamDecl>(E->getDecl())) {
649    llvm::Value *V = LocalDeclMap[IPD];
650    assert(V && "BlockVarDecl not entered in LocalDeclMap?");
651    return LValue::MakeAddr(V, E->getType().getCVRQualifiers());
652  }
653  assert(0 && "Unimp declref");
654  //an invalid LValue, but the assert will
655  //ensure that this point is never reached.
656  return LValue();
657}
658
659LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
660  // __extension__ doesn't affect lvalue-ness.
661  if (E->getOpcode() == UnaryOperator::Extension)
662    return EmitLValue(E->getSubExpr());
663
664  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
665  switch (E->getOpcode()) {
666  default: assert(0 && "Unknown unary operator lvalue!");
667  case UnaryOperator::Deref:
668    return LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()),
669                            ExprTy->getAsPointerType()->getPointeeType()
670                                    .getCVRQualifiers());
671  case UnaryOperator::Real:
672  case UnaryOperator::Imag:
673    LValue LV = EmitLValue(E->getSubExpr());
674    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
675    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
676                                                    Idx, "idx"),
677                            ExprTy.getCVRQualifiers());
678  }
679}
680
681LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
682  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E), 0);
683}
684
685LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
686  std::string GlobalVarName;
687
688  switch (Type) {
689    default:
690      assert(0 && "Invalid type");
691    case PredefinedExpr::Func:
692      GlobalVarName = "__func__.";
693      break;
694    case PredefinedExpr::Function:
695      GlobalVarName = "__FUNCTION__.";
696      break;
697    case PredefinedExpr::PrettyFunction:
698      // FIXME:: Demangle C++ method names
699      GlobalVarName = "__PRETTY_FUNCTION__.";
700      break;
701  }
702
703  std::string FunctionName;
704  if(const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurFuncDecl)) {
705    FunctionName = CGM.getMangledName(FD);
706  } else {
707    // Just get the mangled name.
708    FunctionName = CurFn->getName();
709  }
710
711  GlobalVarName += FunctionName;
712  llvm::Constant *C =
713    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
714  return LValue::MakeAddr(C, 0);
715}
716
717LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
718  switch (E->getIdentType()) {
719  default:
720    return EmitUnsupportedLValue(E, "predefined expression");
721  case PredefinedExpr::Func:
722  case PredefinedExpr::Function:
723  case PredefinedExpr::PrettyFunction:
724    return EmitPredefinedFunctionName(E->getIdentType());
725  }
726}
727
728LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
729  // The index must always be an integer, which is not an aggregate.  Emit it.
730  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
731
732  // If the base is a vector type, then we are forming a vector element lvalue
733  // with this subscript.
734  if (E->getBase()->getType()->isVectorType()) {
735    // Emit the vector as an lvalue to get its address.
736    LValue LHS = EmitLValue(E->getBase());
737    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
738    // FIXME: This should properly sign/zero/extend or truncate Idx to i32.
739    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
740      E->getBase()->getType().getCVRQualifiers());
741  }
742
743  // The base must be a pointer, which is not an aggregate.  Emit it.
744  llvm::Value *Base = EmitScalarExpr(E->getBase());
745
746  // Extend or truncate the index type to 32 or 64-bits.
747  QualType IdxTy  = E->getIdx()->getType();
748  bool IdxSigned = IdxTy->isSignedIntegerType();
749  unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
750  if (IdxBitwidth != LLVMPointerWidth)
751    Idx = Builder.CreateIntCast(Idx, llvm::IntegerType::get(LLVMPointerWidth),
752                                IdxSigned, "idxprom");
753
754  // We know that the pointer points to a type of the correct size, unless the
755  // size is a VLA.
756  if (const VariableArrayType *VAT =
757        getContext().getAsVariableArrayType(E->getType())) {
758    llvm::Value *VLASize = VLASizeMap[VAT];
759
760    Idx = Builder.CreateMul(Idx, VLASize);
761
762    QualType BaseType = getContext().getBaseElementType(VAT);
763
764    uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
765    Idx = Builder.CreateUDiv(Idx,
766                             llvm::ConstantInt::get(Idx->getType(),
767                                                    BaseTypeSize));
768  }
769
770  QualType ExprTy = getContext().getCanonicalType(E->getBase()->getType());
771
772  return LValue::MakeAddr(Builder.CreateGEP(Base, Idx, "arrayidx"),
773                          ExprTy->getAsPointerType()->getPointeeType()
774                               .getCVRQualifiers());
775}
776
777static
778llvm::Constant *GenerateConstantVector(llvm::SmallVector<unsigned, 4> &Elts) {
779  llvm::SmallVector<llvm::Constant *, 4> CElts;
780
781  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
782    CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, Elts[i]));
783
784  return llvm::ConstantVector::get(&CElts[0], CElts.size());
785}
786
787LValue CodeGenFunction::
788EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
789  // Emit the base vector as an l-value.
790  LValue Base;
791
792  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
793  if (!E->isArrow()) {
794    assert(E->getBase()->getType()->isVectorType());
795    Base = EmitLValue(E->getBase());
796  } else {
797    const PointerType *PT = E->getBase()->getType()->getAsPointerType();
798    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
799    Base = LValue::MakeAddr(Ptr, PT->getPointeeType().getCVRQualifiers());
800  }
801
802  // Encode the element access list into a vector of unsigned indices.
803  llvm::SmallVector<unsigned, 4> Indices;
804  E->getEncodedElementAccess(Indices);
805
806  if (Base.isSimple()) {
807    llvm::Constant *CV = GenerateConstantVector(Indices);
808    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
809                                    Base.getQualifiers());
810  }
811  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
812
813  llvm::Constant *BaseElts = Base.getExtVectorElts();
814  llvm::SmallVector<llvm::Constant *, 4> CElts;
815
816  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
817    if (isa<llvm::ConstantAggregateZero>(BaseElts))
818      CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0));
819    else
820      CElts.push_back(BaseElts->getOperand(Indices[i]));
821  }
822  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
823  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
824                                  Base.getQualifiers());
825}
826
827LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
828  bool isUnion = false;
829  bool isIvar = false;
830  Expr *BaseExpr = E->getBase();
831  llvm::Value *BaseValue = NULL;
832  unsigned CVRQualifiers=0;
833
834  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
835  if (E->isArrow()) {
836    BaseValue = EmitScalarExpr(BaseExpr);
837    const PointerType *PTy =
838      cast<PointerType>(getContext().getCanonicalType(BaseExpr->getType()));
839    if (PTy->getPointeeType()->isUnionType())
840      isUnion = true;
841    CVRQualifiers = PTy->getPointeeType().getCVRQualifiers();
842  } else if (isa<ObjCPropertyRefExpr>(BaseExpr) ||
843             isa<ObjCKVCRefExpr>(BaseExpr)) {
844    RValue RV = EmitObjCPropertyGet(BaseExpr);
845    BaseValue = RV.getAggregateAddr();
846    if (BaseExpr->getType()->isUnionType())
847      isUnion = true;
848    CVRQualifiers = BaseExpr->getType().getCVRQualifiers();
849  } else {
850    LValue BaseLV = EmitLValue(BaseExpr);
851    if (BaseLV.isObjCIvar())
852      isIvar = true;
853    // FIXME: this isn't right for bitfields.
854    BaseValue = BaseLV.getAddress();
855    if (BaseExpr->getType()->isUnionType())
856      isUnion = true;
857    CVRQualifiers = BaseExpr->getType().getCVRQualifiers();
858  }
859
860  FieldDecl *Field = dyn_cast<FieldDecl>(E->getMemberDecl());
861  // FIXME: Handle non-field member expressions
862  assert(Field && "No code generation for non-field member references");
863  LValue MemExpLV = EmitLValueForField(BaseValue, Field, isUnion,
864                                       CVRQualifiers);
865  LValue::SetObjCIvar(MemExpLV, isIvar);
866  return MemExpLV;
867}
868
869LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
870                                              FieldDecl* Field,
871                                              unsigned CVRQualifiers) {
872   unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
873  // FIXME: CodeGenTypes should expose a method to get the appropriate
874  // type for FieldTy (the appropriate type is ABI-dependent).
875  const llvm::Type *FieldTy =
876    CGM.getTypes().ConvertTypeForMem(Field->getType());
877  const llvm::PointerType *BaseTy =
878  cast<llvm::PointerType>(BaseValue->getType());
879  unsigned AS = BaseTy->getAddressSpace();
880  BaseValue = Builder.CreateBitCast(BaseValue,
881                                    llvm::PointerType::get(FieldTy, AS),
882                                    "tmp");
883  llvm::Value *V = Builder.CreateGEP(BaseValue,
884                              llvm::ConstantInt::get(llvm::Type::Int32Ty, idx),
885                              "tmp");
886
887  CodeGenTypes::BitFieldInfo bitFieldInfo =
888    CGM.getTypes().getBitFieldInfo(Field);
889  return LValue::MakeBitfield(V, bitFieldInfo.Begin, bitFieldInfo.Size,
890                              Field->getType()->isSignedIntegerType(),
891                            Field->getType().getCVRQualifiers()|CVRQualifiers);
892}
893
894LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
895                                           FieldDecl* Field,
896                                           bool isUnion,
897                                           unsigned CVRQualifiers)
898{
899  if (Field->isBitField())
900    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
901
902  unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
903  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
904
905  // Match union field type.
906  if (isUnion) {
907    const llvm::Type *FieldTy =
908      CGM.getTypes().ConvertTypeForMem(Field->getType());
909    const llvm::PointerType * BaseTy =
910      cast<llvm::PointerType>(BaseValue->getType());
911    unsigned AS = BaseTy->getAddressSpace();
912    V = Builder.CreateBitCast(V,
913                              llvm::PointerType::get(FieldTy, AS),
914                              "tmp");
915  }
916
917  LValue LV =
918    LValue::MakeAddr(V,
919                     Field->getType().getCVRQualifiers()|CVRQualifiers);
920  if (CGM.getLangOptions().ObjC1 &&
921      CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
922    QualType Ty = Field->getType();
923    QualType::GCAttrTypes attr = Ty.getObjCGCAttr();
924    if (attr != QualType::GCNone)
925      // __weak attribute on a field is ignored.
926      LValue::SetObjCType(false, attr == QualType::Strong, LV);
927    else if (getContext().isObjCObjectPointerType(Ty))
928      LValue::SetObjCType(false, true, LV);
929
930  }
931  return LV;
932}
933
934LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E)
935{
936  const llvm::Type *LTy = ConvertType(E->getType());
937  llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral");
938
939  const Expr* InitExpr = E->getInitializer();
940  LValue Result = LValue::MakeAddr(DeclPtr, E->getType().getCVRQualifiers());
941
942  if (E->getType()->isComplexType()) {
943    EmitComplexExprIntoAddr(InitExpr, DeclPtr, false);
944  } else if (hasAggregateLLVMType(E->getType())) {
945    EmitAnyExpr(InitExpr, DeclPtr, false);
946  } else {
947    EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType());
948  }
949
950  return Result;
951}
952
953//===--------------------------------------------------------------------===//
954//                             Expression Emission
955//===--------------------------------------------------------------------===//
956
957
958RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
959  if (const ImplicitCastExpr *IcExpr =
960      dyn_cast<const ImplicitCastExpr>(E->getCallee()))
961    if (const DeclRefExpr *DRExpr =
962        dyn_cast<const DeclRefExpr>(IcExpr->getSubExpr()))
963      if (const FunctionDecl *FDecl =
964          dyn_cast<const FunctionDecl>(DRExpr->getDecl()))
965        if (unsigned builtinID = FDecl->getBuiltinID(getContext()))
966          return EmitBuiltinExpr(FDecl, builtinID, E);
967
968  if (E->getCallee()->getType()->isBlockPointerType())
969    return EmitBlockCallExpr(E);
970
971  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
972  return EmitCallExpr(Callee, E->getCallee()->getType(),
973                      E->arg_begin(), E->arg_end());
974}
975
976RValue CodeGenFunction::EmitCallExpr(Expr *FnExpr,
977                                     CallExpr::const_arg_iterator ArgBeg,
978                                     CallExpr::const_arg_iterator ArgEnd) {
979
980  llvm::Value *Callee = EmitScalarExpr(FnExpr);
981  return EmitCallExpr(Callee, FnExpr->getType(), ArgBeg, ArgEnd);
982}
983
984LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
985  // Can only get l-value for binary operator expressions which are a
986  // simple assignment of aggregate type.
987  if (E->getOpcode() != BinaryOperator::Assign)
988    return EmitUnsupportedLValue(E, "binary l-value expression");
989
990  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
991  EmitAggExpr(E, Temp, false);
992  // FIXME: Are these qualifiers correct?
993  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers());
994}
995
996LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
997  // Can only get l-value for call expression returning aggregate type
998  RValue RV = EmitCallExpr(E);
999  return LValue::MakeAddr(RV.getAggregateAddr(),
1000                          E->getType().getCVRQualifiers());
1001}
1002
1003LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
1004  // FIXME: This shouldn't require another copy.
1005  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
1006  EmitAggExpr(E, Temp, false);
1007  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers());
1008}
1009
1010LValue
1011CodeGenFunction::EmitCXXConditionDeclLValue(const CXXConditionDeclExpr *E) {
1012  EmitLocalBlockVarDecl(*E->getVarDecl());
1013  return EmitDeclRefLValue(E);
1014}
1015
1016LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
1017  // Can only get l-value for message expression returning aggregate type
1018  RValue RV = EmitObjCMessageExpr(E);
1019  // FIXME: can this be volatile?
1020  return LValue::MakeAddr(RV.getAggregateAddr(),
1021                          E->getType().getCVRQualifiers());
1022}
1023
1024llvm::Value *CodeGenFunction::EmitIvarOffset(ObjCInterfaceDecl *Interface,
1025                                             const ObjCIvarDecl *Ivar) {
1026  // Objective-C objects are traditionally C structures with their layout
1027  // defined at compile-time.  In some implementations, their layout is not
1028  // defined until run time in order to allow instance variables to be added to
1029  // a class without recompiling all of the subclasses.  If this is the case
1030  // then the CGObjCRuntime subclass must return true to LateBoundIvars and
1031  // implement the lookup itself.
1032  if (CGM.getObjCRuntime().LateBoundIVars())
1033    assert(0 && "late-bound ivars are unsupported");
1034  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
1035}
1036
1037LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
1038                                          llvm::Value *BaseValue,
1039                                          const ObjCIvarDecl *Ivar,
1040                                          const FieldDecl *Field,
1041                                          unsigned CVRQualifiers) {
1042  // See comment in EmitIvarOffset.
1043  if (CGM.getObjCRuntime().LateBoundIVars())
1044    assert(0 && "late-bound ivars are unsupported");
1045
1046  LValue LV = CGM.getObjCRuntime().EmitObjCValueForIvar(*this,
1047                                                        ObjectTy,
1048                                                        BaseValue, Ivar, Field,
1049                                                        CVRQualifiers);
1050  SetDeclObjCGCAttrInLvalue(getContext(), Ivar->getType(), LV);
1051  return LV;
1052}
1053
1054LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
1055  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
1056  llvm::Value *BaseValue = 0;
1057  const Expr *BaseExpr = E->getBase();
1058  unsigned CVRQualifiers = 0;
1059  QualType ObjectTy;
1060  if (E->isArrow()) {
1061    BaseValue = EmitScalarExpr(BaseExpr);
1062    const PointerType *PTy =
1063      cast<PointerType>(getContext().getCanonicalType(BaseExpr->getType()));
1064    ObjectTy = PTy->getPointeeType();
1065    CVRQualifiers = ObjectTy.getCVRQualifiers();
1066  } else {
1067    LValue BaseLV = EmitLValue(BaseExpr);
1068    // FIXME: this isn't right for bitfields.
1069    BaseValue = BaseLV.getAddress();
1070    ObjectTy = BaseExpr->getType();
1071    CVRQualifiers = ObjectTy.getCVRQualifiers();
1072  }
1073
1074  return EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
1075                           getContext().getFieldDecl(E), CVRQualifiers);
1076}
1077
1078LValue
1079CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
1080  // This is a special l-value that just issues sends when we load or
1081  // store through it.
1082  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
1083}
1084
1085LValue
1086CodeGenFunction::EmitObjCKVCRefLValue(const ObjCKVCRefExpr *E) {
1087  // This is a special l-value that just issues sends when we load or
1088  // store through it.
1089  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
1090}
1091
1092LValue
1093CodeGenFunction::EmitObjCSuperExpr(const ObjCSuperExpr *E) {
1094  return EmitUnsupportedLValue(E, "use of super");
1095}
1096
1097RValue CodeGenFunction::EmitCallExpr(llvm::Value *Callee, QualType CalleeType,
1098                                     CallExpr::const_arg_iterator ArgBeg,
1099                                     CallExpr::const_arg_iterator ArgEnd) {
1100  // Get the actual function type. The callee type will always be a
1101  // pointer to function type or a block pointer type.
1102  QualType ResultType;
1103  if (const BlockPointerType *BPT = dyn_cast<BlockPointerType>(CalleeType)) {
1104    ResultType = BPT->getPointeeType()->getAsFunctionType()->getResultType();
1105  } else {
1106    assert(CalleeType->isFunctionPointerType() &&
1107           "Call must have function pointer type!");
1108    QualType FnType = CalleeType->getAsPointerType()->getPointeeType();
1109    ResultType = FnType->getAsFunctionType()->getResultType();
1110  }
1111
1112  CallArgList Args;
1113  for (CallExpr::const_arg_iterator I = ArgBeg; I != ArgEnd; ++I)
1114    Args.push_back(std::make_pair(EmitAnyExprToTemp(*I),
1115                                  I->getType()));
1116
1117  return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args),
1118                  Callee, Args);
1119}
1120