CGObjC.cpp revision 193326 
1//===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===//
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 Objective-C code as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CGObjCRuntime.h"
15#include "CodeGenFunction.h"
16#include "CodeGenModule.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclObjC.h"
19#include "clang/AST/StmtObjC.h"
20#include "clang/Basic/Diagnostic.h"
21#include "llvm/ADT/STLExtras.h"
22#include "llvm/Target/TargetData.h"
23using namespace clang;
24using namespace CodeGen;
25
26/// Emits an instance of NSConstantString representing the object.
27llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E)
28{
29  llvm::Constant *C = CGM.getObjCRuntime().GenerateConstantString(E);
30  // FIXME: This bitcast should just be made an invariant on the Runtime.
31  return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
32}
33
34/// Emit a selector.
35llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
36  // Untyped selector.
37  // Note that this implementation allows for non-constant strings to be passed
38  // as arguments to @selector().  Currently, the only thing preventing this
39  // behaviour is the type checking in the front end.
40  return CGM.getObjCRuntime().GetSelector(Builder, E->getSelector());
41}
42
43llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
44  // FIXME: This should pass the Decl not the name.
45  return CGM.getObjCRuntime().GenerateProtocolRef(Builder, E->getProtocol());
46}
47
48
49RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E) {
50  // Only the lookup mechanism and first two arguments of the method
51  // implementation vary between runtimes.  We can get the receiver and
52  // arguments in generic code.
53
54  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
55  const Expr *ReceiverExpr = E->getReceiver();
56  bool isSuperMessage = false;
57  bool isClassMessage = false;
58  // Find the receiver
59  llvm::Value *Receiver;
60  if (!ReceiverExpr) {
61    const ObjCInterfaceDecl *OID = E->getClassInfo().first;
62
63    // Very special case, super send in class method. The receiver is
64    // self (the class object) and the send uses super semantics.
65    if (!OID) {
66      assert(E->getClassName()->isStr("super") &&
67             "Unexpected missing class interface in message send.");
68      isSuperMessage = true;
69      Receiver = LoadObjCSelf();
70    } else {
71      Receiver = Runtime.GetClass(Builder, OID);
72    }
73
74    isClassMessage = true;
75  } else if (isa<ObjCSuperExpr>(E->getReceiver())) {
76    isSuperMessage = true;
77    Receiver = LoadObjCSelf();
78  } else {
79    Receiver = EmitScalarExpr(E->getReceiver());
80  }
81
82  CallArgList Args;
83  EmitCallArgs(Args, E->getMethodDecl(), E->arg_begin(), E->arg_end());
84
85  if (isSuperMessage) {
86    // super is only valid in an Objective-C method
87    const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
88    bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
89    return Runtime.GenerateMessageSendSuper(*this, E->getType(),
90                                            E->getSelector(),
91                                            OMD->getClassInterface(),
92                                            isCategoryImpl,
93                                            Receiver,
94                                            isClassMessage,
95                                            Args);
96  }
97  return Runtime.GenerateMessageSend(*this, E->getType(), E->getSelector(),
98                                     Receiver, isClassMessage, Args,
99                                     E->getMethodDecl());
100}
101
102/// StartObjCMethod - Begin emission of an ObjCMethod. This generates
103/// the LLVM function and sets the other context used by
104/// CodeGenFunction.
105void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
106                                      const ObjCContainerDecl *CD) {
107  FunctionArgList Args;
108  llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
109
110  const CGFunctionInfo &FI = CGM.getTypes().getFunctionInfo(OMD);
111  CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
112
113  Args.push_back(std::make_pair(OMD->getSelfDecl(),
114                                OMD->getSelfDecl()->getType()));
115  Args.push_back(std::make_pair(OMD->getCmdDecl(),
116                                OMD->getCmdDecl()->getType()));
117
118  for (ObjCMethodDecl::param_iterator PI = OMD->param_begin(),
119       E = OMD->param_end(); PI != E; ++PI)
120    Args.push_back(std::make_pair(*PI, (*PI)->getType()));
121
122  StartFunction(OMD, OMD->getResultType(), Fn, Args, OMD->getLocEnd());
123}
124
125/// Generate an Objective-C method.  An Objective-C method is a C function with
126/// its pointer, name, and types registered in the class struture.
127void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
128  // Check if we should generate debug info for this method.
129  if (CGM.getDebugInfo() && !OMD->hasAttr<NodebugAttr>())
130    DebugInfo = CGM.getDebugInfo();
131  StartObjCMethod(OMD, OMD->getClassInterface());
132  EmitStmt(OMD->getBody(getContext()));
133  FinishFunction(OMD->getBodyRBrace(getContext()));
134}
135
136// FIXME: I wasn't sure about the synthesis approach. If we end up generating an
137// AST for the whole body we can just fall back to having a GenerateFunction
138// which takes the body Stmt.
139
140/// GenerateObjCGetter - Generate an Objective-C property getter
141/// function. The given Decl must be an ObjCImplementationDecl. @synthesize
142/// is illegal within a category.
143void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
144                                         const ObjCPropertyImplDecl *PID) {
145  ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
146  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
147  ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
148  assert(OMD && "Invalid call to generate getter (empty method)");
149  // FIXME: This is rather murky, we create this here since they will not have
150  // been created by Sema for us.
151  OMD->createImplicitParams(getContext(), IMP->getClassInterface());
152  StartObjCMethod(OMD, IMP->getClassInterface());
153
154  // Determine if we should use an objc_getProperty call for
155  // this. Non-atomic properties are directly evaluated.
156  // atomic 'copy' and 'retain' properties are also directly
157  // evaluated in gc-only mode.
158  if (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly &&
159      !(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic) &&
160      (PD->getSetterKind() == ObjCPropertyDecl::Copy ||
161       PD->getSetterKind() == ObjCPropertyDecl::Retain)) {
162    llvm::Value *GetPropertyFn =
163      CGM.getObjCRuntime().GetPropertyGetFunction();
164
165    if (!GetPropertyFn) {
166      CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy");
167      FinishFunction();
168      return;
169    }
170
171    // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
172    // FIXME: Can't this be simpler? This might even be worse than the
173    // corresponding gcc code.
174    CodeGenTypes &Types = CGM.getTypes();
175    ValueDecl *Cmd = OMD->getCmdDecl();
176    llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd");
177    QualType IdTy = getContext().getObjCIdType();
178    llvm::Value *SelfAsId =
179      Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
180    llvm::Value *Offset = EmitIvarOffset(IMP->getClassInterface(), Ivar);
181    llvm::Value *True =
182      llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 1);
183    CallArgList Args;
184    Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy));
185    Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType()));
186    Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy));
187    Args.push_back(std::make_pair(RValue::get(True), getContext().BoolTy));
188    // FIXME: We shouldn't need to get the function info here, the
189    // runtime already should have computed it to build the function.
190    RValue RV = EmitCall(Types.getFunctionInfo(PD->getType(), Args),
191                         GetPropertyFn, Args);
192    // We need to fix the type here. Ivars with copy & retain are
193    // always objects so we don't need to worry about complex or
194    // aggregates.
195    RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(),
196                                           Types.ConvertType(PD->getType())));
197    EmitReturnOfRValue(RV, PD->getType());
198  } else {
199    LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), Ivar, 0);
200    if (hasAggregateLLVMType(Ivar->getType())) {
201      EmitAggregateCopy(ReturnValue, LV.getAddress(), Ivar->getType());
202    }
203    else {
204      CodeGenTypes &Types = CGM.getTypes();
205      RValue RV = EmitLoadOfLValue(LV, Ivar->getType());
206      RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(),
207                       Types.ConvertType(PD->getType())));
208      EmitReturnOfRValue(RV, PD->getType());
209    }
210  }
211
212  FinishFunction();
213}
214
215/// GenerateObjCSetter - Generate an Objective-C property setter
216/// function. The given Decl must be an ObjCImplementationDecl. @synthesize
217/// is illegal within a category.
218void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
219                                         const ObjCPropertyImplDecl *PID) {
220  ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
221  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
222  ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
223  assert(OMD && "Invalid call to generate setter (empty method)");
224  // FIXME: This is rather murky, we create this here since they will not have
225  // been created by Sema for us.
226  OMD->createImplicitParams(getContext(), IMP->getClassInterface());
227  StartObjCMethod(OMD, IMP->getClassInterface());
228
229  bool IsCopy = PD->getSetterKind() == ObjCPropertyDecl::Copy;
230  bool IsAtomic =
231    !(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic);
232
233  // Determine if we should use an objc_setProperty call for
234  // this. Properties with 'copy' semantics always use it, as do
235  // non-atomic properties with 'release' semantics as long as we are
236  // not in gc-only mode.
237  if (IsCopy ||
238      (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly &&
239       PD->getSetterKind() == ObjCPropertyDecl::Retain)) {
240    llvm::Value *SetPropertyFn =
241      CGM.getObjCRuntime().GetPropertySetFunction();
242
243    if (!SetPropertyFn) {
244      CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy");
245      FinishFunction();
246      return;
247    }
248
249    // Emit objc_setProperty((id) self, _cmd, offset, arg,
250    //                       <is-atomic>, <is-copy>).
251    // FIXME: Can't this be simpler? This might even be worse than the
252    // corresponding gcc code.
253    CodeGenTypes &Types = CGM.getTypes();
254    ValueDecl *Cmd = OMD->getCmdDecl();
255    llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd");
256    QualType IdTy = getContext().getObjCIdType();
257    llvm::Value *SelfAsId =
258      Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
259    llvm::Value *Offset = EmitIvarOffset(IMP->getClassInterface(), Ivar);
260    llvm::Value *Arg = LocalDeclMap[*OMD->param_begin()];
261    llvm::Value *ArgAsId =
262      Builder.CreateBitCast(Builder.CreateLoad(Arg, "arg"),
263                            Types.ConvertType(IdTy));
264    llvm::Value *True =
265      llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 1);
266    llvm::Value *False =
267      llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 0);
268    CallArgList Args;
269    Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy));
270    Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType()));
271    Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy));
272    Args.push_back(std::make_pair(RValue::get(ArgAsId), IdTy));
273    Args.push_back(std::make_pair(RValue::get(IsAtomic ? True : False),
274                                  getContext().BoolTy));
275    Args.push_back(std::make_pair(RValue::get(IsCopy ? True : False),
276                                  getContext().BoolTy));
277    // FIXME: We shouldn't need to get the function info here, the runtime
278    // already should have computed it to build the function.
279    EmitCall(Types.getFunctionInfo(getContext().VoidTy, Args),
280             SetPropertyFn, Args);
281  } else {
282    SourceLocation Loc = PD->getLocation();
283    ValueDecl *Self = OMD->getSelfDecl();
284    ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
285    DeclRefExpr Base(Self, Self->getType(), Loc);
286    ParmVarDecl *ArgDecl = *OMD->param_begin();
287    DeclRefExpr Arg(ArgDecl, ArgDecl->getType(), Loc);
288    ObjCIvarRefExpr IvarRef(Ivar, Ivar->getType(), Loc, &Base,
289                            true, true);
290    BinaryOperator Assign(&IvarRef, &Arg, BinaryOperator::Assign,
291                          Ivar->getType(), Loc);
292    EmitStmt(&Assign);
293  }
294
295  FinishFunction();
296}
297
298llvm::Value *CodeGenFunction::LoadObjCSelf() {
299  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
300  // See if we need to lazily forward self inside a block literal.
301  BlockForwardSelf();
302  return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self");
303}
304
305QualType CodeGenFunction::TypeOfSelfObject() {
306  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
307  ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
308  const PointerType *PTy =
309    cast<PointerType>(getContext().getCanonicalType(selfDecl->getType()));
310  return PTy->getPointeeType();
311}
312
313RValue CodeGenFunction::EmitObjCSuperPropertyGet(const Expr *Exp,
314                                                 const Selector &S) {
315  llvm::Value *Receiver = LoadObjCSelf();
316  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
317  bool isClassMessage = OMD->isClassMethod();
318  bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
319  return CGM.getObjCRuntime().GenerateMessageSendSuper(*this,
320                                                       Exp->getType(),
321                                                       S,
322                                                       OMD->getClassInterface(),
323                                                       isCategoryImpl,
324                                                       Receiver,
325                                                       isClassMessage,
326                                                       CallArgList());
327
328}
329
330RValue CodeGenFunction::EmitObjCPropertyGet(const Expr *Exp) {
331  // FIXME: Split it into two separate routines.
332  if (const ObjCPropertyRefExpr *E = dyn_cast<ObjCPropertyRefExpr>(Exp)) {
333    Selector S = E->getProperty()->getGetterName();
334    if (isa<ObjCSuperExpr>(E->getBase()))
335      return EmitObjCSuperPropertyGet(E, S);
336    return CGM.getObjCRuntime().
337             GenerateMessageSend(*this, Exp->getType(), S,
338                                 EmitScalarExpr(E->getBase()),
339                                 false, CallArgList());
340  }
341  else {
342    const ObjCKVCRefExpr *KE = cast<ObjCKVCRefExpr>(Exp);
343    Selector S = KE->getGetterMethod()->getSelector();
344    llvm::Value *Receiver;
345    if (KE->getClassProp()) {
346      const ObjCInterfaceDecl *OID = KE->getClassProp();
347      Receiver = CGM.getObjCRuntime().GetClass(Builder, OID);
348    }
349    else if (isa<ObjCSuperExpr>(KE->getBase()))
350      return EmitObjCSuperPropertyGet(KE, S);
351    else
352      Receiver = EmitScalarExpr(KE->getBase());
353    return CGM.getObjCRuntime().
354             GenerateMessageSend(*this, Exp->getType(), S,
355                                 Receiver,
356                                 KE->getClassProp() != 0, CallArgList());
357  }
358}
359
360void CodeGenFunction::EmitObjCSuperPropertySet(const Expr *Exp,
361                                               const Selector &S,
362                                               RValue Src) {
363  CallArgList Args;
364  llvm::Value *Receiver = LoadObjCSelf();
365  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
366  bool isClassMessage = OMD->isClassMethod();
367  bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
368  Args.push_back(std::make_pair(Src, Exp->getType()));
369  CGM.getObjCRuntime().GenerateMessageSendSuper(*this,
370                                                Exp->getType(),
371                                                S,
372                                                OMD->getClassInterface(),
373                                                isCategoryImpl,
374                                                Receiver,
375                                                isClassMessage,
376                                                Args);
377  return;
378}
379
380void CodeGenFunction::EmitObjCPropertySet(const Expr *Exp,
381                                          RValue Src) {
382  // FIXME: Split it into two separate routines.
383  if (const ObjCPropertyRefExpr *E = dyn_cast<ObjCPropertyRefExpr>(Exp)) {
384    Selector S = E->getProperty()->getSetterName();
385    if (isa<ObjCSuperExpr>(E->getBase())) {
386      EmitObjCSuperPropertySet(E, S, Src);
387      return;
388    }
389    CallArgList Args;
390    Args.push_back(std::make_pair(Src, E->getType()));
391    CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S,
392                                             EmitScalarExpr(E->getBase()),
393                                             false, Args);
394  }
395  else if (const ObjCKVCRefExpr *E = dyn_cast<ObjCKVCRefExpr>(Exp)) {
396    Selector S = E->getSetterMethod()->getSelector();
397    CallArgList Args;
398    llvm::Value *Receiver;
399    if (E->getClassProp()) {
400      const ObjCInterfaceDecl *OID = E->getClassProp();
401      Receiver = CGM.getObjCRuntime().GetClass(Builder, OID);
402    }
403    else if (isa<ObjCSuperExpr>(E->getBase())) {
404      EmitObjCSuperPropertySet(E, S, Src);
405      return;
406    }
407    else
408      Receiver = EmitScalarExpr(E->getBase());
409    Args.push_back(std::make_pair(Src, E->getType()));
410    CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S,
411                                             Receiver,
412                                             E->getClassProp() != 0, Args);
413  }
414  else
415    assert (0 && "bad expression node in EmitObjCPropertySet");
416}
417
418void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
419  llvm::Constant *EnumerationMutationFn =
420    CGM.getObjCRuntime().EnumerationMutationFunction();
421  llvm::Value *DeclAddress;
422  QualType ElementTy;
423
424  if (!EnumerationMutationFn) {
425    CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
426    return;
427  }
428
429  if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
430    EmitStmt(SD);
431    assert(HaveInsertPoint() && "DeclStmt destroyed insert point!");
432    const Decl* D = SD->getSingleDecl();
433    ElementTy = cast<ValueDecl>(D)->getType();
434    DeclAddress = LocalDeclMap[D];
435  } else {
436    ElementTy = cast<Expr>(S.getElement())->getType();
437    DeclAddress = 0;
438  }
439
440  // Fast enumeration state.
441  QualType StateTy = getContext().getObjCFastEnumerationStateType();
442  llvm::AllocaInst *StatePtr = CreateTempAlloca(ConvertType(StateTy),
443                                                "state.ptr");
444  StatePtr->setAlignment(getContext().getTypeAlign(StateTy) >> 3);
445  EmitMemSetToZero(StatePtr, StateTy);
446
447  // Number of elements in the items array.
448  static const unsigned NumItems = 16;
449
450  // Get selector
451  llvm::SmallVector<IdentifierInfo*, 3> II;
452  II.push_back(&CGM.getContext().Idents.get("countByEnumeratingWithState"));
453  II.push_back(&CGM.getContext().Idents.get("objects"));
454  II.push_back(&CGM.getContext().Idents.get("count"));
455  Selector FastEnumSel = CGM.getContext().Selectors.getSelector(II.size(),
456                                                                &II[0]);
457
458  QualType ItemsTy =
459    getContext().getConstantArrayType(getContext().getObjCIdType(),
460                                      llvm::APInt(32, NumItems),
461                                      ArrayType::Normal, 0);
462  llvm::Value *ItemsPtr = CreateTempAlloca(ConvertType(ItemsTy), "items.ptr");
463
464  llvm::Value *Collection = EmitScalarExpr(S.getCollection());
465
466  CallArgList Args;
467  Args.push_back(std::make_pair(RValue::get(StatePtr),
468                                getContext().getPointerType(StateTy)));
469
470  Args.push_back(std::make_pair(RValue::get(ItemsPtr),
471                                getContext().getPointerType(ItemsTy)));
472
473  const llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy);
474  llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems);
475  Args.push_back(std::make_pair(RValue::get(Count),
476                                getContext().UnsignedLongTy));
477
478  RValue CountRV =
479    CGM.getObjCRuntime().GenerateMessageSend(*this,
480                                             getContext().UnsignedLongTy,
481                                             FastEnumSel,
482                                             Collection, false, Args);
483
484  llvm::Value *LimitPtr = CreateTempAlloca(UnsignedLongLTy, "limit.ptr");
485  Builder.CreateStore(CountRV.getScalarVal(), LimitPtr);
486
487  llvm::BasicBlock *NoElements = createBasicBlock("noelements");
488  llvm::BasicBlock *SetStartMutations = createBasicBlock("setstartmutations");
489
490  llvm::Value *Limit = Builder.CreateLoad(LimitPtr);
491  llvm::Value *Zero = llvm::Constant::getNullValue(UnsignedLongLTy);
492
493  llvm::Value *IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero");
494  Builder.CreateCondBr(IsZero, NoElements, SetStartMutations);
495
496  EmitBlock(SetStartMutations);
497
498  llvm::Value *StartMutationsPtr =
499    CreateTempAlloca(UnsignedLongLTy);
500
501  llvm::Value *StateMutationsPtrPtr =
502    Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
503  llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr,
504                                                      "mutationsptr");
505
506  llvm::Value *StateMutations = Builder.CreateLoad(StateMutationsPtr,
507                                                   "mutations");
508
509  Builder.CreateStore(StateMutations, StartMutationsPtr);
510
511  llvm::BasicBlock *LoopStart = createBasicBlock("loopstart");
512  EmitBlock(LoopStart);
513
514  llvm::Value *CounterPtr = CreateTempAlloca(UnsignedLongLTy, "counter.ptr");
515  Builder.CreateStore(Zero, CounterPtr);
516
517  llvm::BasicBlock *LoopBody = createBasicBlock("loopbody");
518  EmitBlock(LoopBody);
519
520  StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
521  StateMutations = Builder.CreateLoad(StateMutationsPtr, "statemutations");
522
523  llvm::Value *StartMutations = Builder.CreateLoad(StartMutationsPtr,
524                                                   "mutations");
525  llvm::Value *MutationsEqual = Builder.CreateICmpEQ(StateMutations,
526                                                     StartMutations,
527                                                     "tobool");
528
529
530  llvm::BasicBlock *WasMutated = createBasicBlock("wasmutated");
531  llvm::BasicBlock *WasNotMutated = createBasicBlock("wasnotmutated");
532
533  Builder.CreateCondBr(MutationsEqual, WasNotMutated, WasMutated);
534
535  EmitBlock(WasMutated);
536  llvm::Value *V =
537    Builder.CreateBitCast(Collection,
538                          ConvertType(getContext().getObjCIdType()),
539                          "tmp");
540  CallArgList Args2;
541  Args2.push_back(std::make_pair(RValue::get(V),
542                                getContext().getObjCIdType()));
543  // FIXME: We shouldn't need to get the function info here, the runtime already
544  // should have computed it to build the function.
545  EmitCall(CGM.getTypes().getFunctionInfo(getContext().VoidTy, Args2),
546           EnumerationMutationFn, Args2);
547
548  EmitBlock(WasNotMutated);
549
550  llvm::Value *StateItemsPtr =
551    Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
552
553  llvm::Value *Counter = Builder.CreateLoad(CounterPtr, "counter");
554
555  llvm::Value *EnumStateItems = Builder.CreateLoad(StateItemsPtr,
556                                                   "stateitems");
557
558  llvm::Value *CurrentItemPtr =
559    Builder.CreateGEP(EnumStateItems, Counter, "currentitem.ptr");
560
561  llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr, "currentitem");
562
563  // Cast the item to the right type.
564  CurrentItem = Builder.CreateBitCast(CurrentItem,
565                                      ConvertType(ElementTy), "tmp");
566
567  if (!DeclAddress) {
568    LValue LV = EmitLValue(cast<Expr>(S.getElement()));
569
570    // Set the value to null.
571    Builder.CreateStore(CurrentItem, LV.getAddress());
572  } else
573    Builder.CreateStore(CurrentItem, DeclAddress);
574
575  // Increment the counter.
576  Counter = Builder.CreateAdd(Counter,
577                              llvm::ConstantInt::get(UnsignedLongLTy, 1));
578  Builder.CreateStore(Counter, CounterPtr);
579
580  llvm::BasicBlock *LoopEnd = createBasicBlock("loopend");
581  llvm::BasicBlock *AfterBody = createBasicBlock("afterbody");
582
583  BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
584
585  EmitStmt(S.getBody());
586
587  BreakContinueStack.pop_back();
588
589  EmitBlock(AfterBody);
590
591  llvm::BasicBlock *FetchMore = createBasicBlock("fetchmore");
592
593  Counter = Builder.CreateLoad(CounterPtr);
594  Limit = Builder.CreateLoad(LimitPtr);
595  llvm::Value *IsLess = Builder.CreateICmpULT(Counter, Limit, "isless");
596  Builder.CreateCondBr(IsLess, LoopBody, FetchMore);
597
598  // Fetch more elements.
599  EmitBlock(FetchMore);
600
601  CountRV =
602    CGM.getObjCRuntime().GenerateMessageSend(*this,
603                                             getContext().UnsignedLongTy,
604                                             FastEnumSel,
605                                             Collection, false, Args);
606  Builder.CreateStore(CountRV.getScalarVal(), LimitPtr);
607  Limit = Builder.CreateLoad(LimitPtr);
608
609  IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero");
610  Builder.CreateCondBr(IsZero, NoElements, LoopStart);
611
612  // No more elements.
613  EmitBlock(NoElements);
614
615  if (!DeclAddress) {
616    // If the element was not a declaration, set it to be null.
617
618    LValue LV = EmitLValue(cast<Expr>(S.getElement()));
619
620    // Set the value to null.
621    Builder.CreateStore(llvm::Constant::getNullValue(ConvertType(ElementTy)),
622                        LV.getAddress());
623  }
624
625  EmitBlock(LoopEnd);
626}
627
628void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S)
629{
630  CGM.getObjCRuntime().EmitTryOrSynchronizedStmt(*this, S);
631}
632
633void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S)
634{
635  CGM.getObjCRuntime().EmitThrowStmt(*this, S);
636}
637
638void CodeGenFunction::EmitObjCAtSynchronizedStmt(
639                                              const ObjCAtSynchronizedStmt &S)
640{
641  CGM.getObjCRuntime().EmitTryOrSynchronizedStmt(*this, S);
642}
643
644CGObjCRuntime::~CGObjCRuntime() {}
645