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"
23 using namespace clang;
24 using namespace CodeGen;
25 
26 /// Emits an instance of NSConstantString representing the object.
27 llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E)
28 {
29   llvm::Constant *C =
30       CGM.getObjCRuntime().GenerateConstantString(E->getString());
31   // FIXME: This bitcast should just be made an invariant on the Runtime.
32   return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
33 }
34 
35 /// Emit a selector.
36 llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
37   // Untyped selector.
38   // Note that this implementation allows for non-constant strings to be passed
39   // as arguments to @selector().  Currently, the only thing preventing this
40   // behaviour is the type checking in the front end.
41   return CGM.getObjCRuntime().GetSelector(Builder, E->getSelector());
42 }
43 
44 llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
45   // FIXME: This should pass the Decl not the name.
46   return CGM.getObjCRuntime().GenerateProtocolRef(Builder, E->getProtocol());
47 }
48 
49 
50 RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E) {
51   // Only the lookup mechanism and first two arguments of the method
52   // implementation vary between runtimes.  We can get the receiver and
53   // arguments in generic code.
54 
55   CGObjCRuntime &Runtime = CGM.getObjCRuntime();
56   bool isSuperMessage = false;
57   bool isClassMessage = false;
58   ObjCInterfaceDecl *OID = 0;
59   // Find the receiver
60   llvm::Value *Receiver = 0;
61   switch (E->getReceiverKind()) {
62   case ObjCMessageExpr::Instance:
63     Receiver = EmitScalarExpr(E->getInstanceReceiver());
64     break;
65 
66   case ObjCMessageExpr::Class: {
67     const ObjCInterfaceType *IFace
68       = E->getClassReceiver()->getAs<ObjCInterfaceType>();
69     OID = IFace->getDecl();
70     assert(IFace && "Invalid Objective-C class message send");
71     Receiver = Runtime.GetClass(Builder, OID);
72     isClassMessage = true;
73     break;
74   }
75 
76   case ObjCMessageExpr::SuperInstance:
77     Receiver = LoadObjCSelf();
78     isSuperMessage = true;
79     break;
80 
81   case ObjCMessageExpr::SuperClass:
82     Receiver = LoadObjCSelf();
83     isSuperMessage = true;
84     isClassMessage = true;
85     break;
86   }
87 
88   CallArgList Args;
89   EmitCallArgs(Args, E->getMethodDecl(), E->arg_begin(), E->arg_end());
90 
91   if (isSuperMessage) {
92     // super is only valid in an Objective-C method
93     const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
94     bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
95     return Runtime.GenerateMessageSendSuper(*this, E->getType(),
96                                             E->getSelector(),
97                                             OMD->getClassInterface(),
98                                             isCategoryImpl,
99                                             Receiver,
100                                             isClassMessage,
101                                             Args,
102                                             E->getMethodDecl());
103   }
104 
105   return Runtime.GenerateMessageSend(*this, E->getType(), E->getSelector(),
106                                      Receiver, Args, OID,
107                                      E->getMethodDecl());
108 }
109 
110 /// StartObjCMethod - Begin emission of an ObjCMethod. This generates
111 /// the LLVM function and sets the other context used by
112 /// CodeGenFunction.
113 void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
114                                       const ObjCContainerDecl *CD) {
115   FunctionArgList Args;
116   // Check if we should generate debug info for this method.
117   if (CGM.getDebugInfo() && !OMD->hasAttr<NoDebugAttr>())
118     DebugInfo = CGM.getDebugInfo();
119 
120   llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
121 
122   const CGFunctionInfo &FI = CGM.getTypes().getFunctionInfo(OMD);
123   CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
124 
125   Args.push_back(std::make_pair(OMD->getSelfDecl(),
126                                 OMD->getSelfDecl()->getType()));
127   Args.push_back(std::make_pair(OMD->getCmdDecl(),
128                                 OMD->getCmdDecl()->getType()));
129 
130   for (ObjCMethodDecl::param_iterator PI = OMD->param_begin(),
131        E = OMD->param_end(); PI != E; ++PI)
132     Args.push_back(std::make_pair(*PI, (*PI)->getType()));
133 
134   StartFunction(OMD, OMD->getResultType(), Fn, Args, OMD->getLocStart());
135 }
136 
137 /// Generate an Objective-C method.  An Objective-C method is a C function with
138 /// its pointer, name, and types registered in the class struture.
139 void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
140   StartObjCMethod(OMD, OMD->getClassInterface());
141   EmitStmt(OMD->getBody());
142   FinishFunction(OMD->getBodyRBrace());
143 }
144 
145 // FIXME: I wasn't sure about the synthesis approach. If we end up generating an
146 // AST for the whole body we can just fall back to having a GenerateFunction
147 // which takes the body Stmt.
148 
149 /// GenerateObjCGetter - Generate an Objective-C property getter
150 /// function. The given Decl must be an ObjCImplementationDecl. @synthesize
151 /// is illegal within a category.
152 void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
153                                          const ObjCPropertyImplDecl *PID) {
154   ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
155   const ObjCPropertyDecl *PD = PID->getPropertyDecl();
156   bool IsAtomic =
157     !(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic);
158   ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
159   assert(OMD && "Invalid call to generate getter (empty method)");
160   StartObjCMethod(OMD, IMP->getClassInterface());
161 
162   // Determine if we should use an objc_getProperty call for
163   // this. Non-atomic properties are directly evaluated.
164   // atomic 'copy' and 'retain' properties are also directly
165   // evaluated in gc-only mode.
166   if (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly &&
167       IsAtomic &&
168       (PD->getSetterKind() == ObjCPropertyDecl::Copy ||
169        PD->getSetterKind() == ObjCPropertyDecl::Retain)) {
170     llvm::Value *GetPropertyFn =
171       CGM.getObjCRuntime().GetPropertyGetFunction();
172 
173     if (!GetPropertyFn) {
174       CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy");
175       FinishFunction();
176       return;
177     }
178 
179     // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
180     // FIXME: Can't this be simpler? This might even be worse than the
181     // corresponding gcc code.
182     CodeGenTypes &Types = CGM.getTypes();
183     ValueDecl *Cmd = OMD->getCmdDecl();
184     llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd");
185     QualType IdTy = getContext().getObjCIdType();
186     llvm::Value *SelfAsId =
187       Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
188     llvm::Value *Offset = EmitIvarOffset(IMP->getClassInterface(), Ivar);
189     llvm::Value *True =
190       llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 1);
191     CallArgList Args;
192     Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy));
193     Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType()));
194     Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy));
195     Args.push_back(std::make_pair(RValue::get(True), getContext().BoolTy));
196     // FIXME: We shouldn't need to get the function info here, the
197     // runtime already should have computed it to build the function.
198     RValue RV = EmitCall(Types.getFunctionInfo(PD->getType(), Args,
199                                                FunctionType::ExtInfo()),
200                          GetPropertyFn, ReturnValueSlot(), Args);
201     // We need to fix the type here. Ivars with copy & retain are
202     // always objects so we don't need to worry about complex or
203     // aggregates.
204     RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(),
205                                            Types.ConvertType(PD->getType())));
206     EmitReturnOfRValue(RV, PD->getType());
207   } else {
208     if (Ivar->getType()->isAnyComplexType()) {
209       LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(),
210                                     Ivar, 0);
211       ComplexPairTy Pair = LoadComplexFromAddr(LV.getAddress(),
212                                                LV.isVolatileQualified());
213       StoreComplexToAddr(Pair, ReturnValue, LV.isVolatileQualified());
214     }
215     else if (hasAggregateLLVMType(Ivar->getType())) {
216       bool IsStrong = false;
217       if ((IsAtomic || (IsStrong = IvarTypeWithAggrGCObjects(Ivar->getType())))
218           && CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect
219           && CGM.getObjCRuntime().GetCopyStructFunction()) {
220         LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(),
221                                       Ivar, 0);
222         llvm::Value *GetCopyStructFn =
223           CGM.getObjCRuntime().GetCopyStructFunction();
224         CodeGenTypes &Types = CGM.getTypes();
225         // objc_copyStruct (ReturnValue, &structIvar,
226         //                  sizeof (Type of Ivar), isAtomic, false);
227         CallArgList Args;
228         RValue RV = RValue::get(Builder.CreateBitCast(ReturnValue,
229                                     Types.ConvertType(getContext().VoidPtrTy)));
230         Args.push_back(std::make_pair(RV, getContext().VoidPtrTy));
231         RV = RValue::get(Builder.CreateBitCast(LV.getAddress(),
232                                     Types.ConvertType(getContext().VoidPtrTy)));
233         Args.push_back(std::make_pair(RV, getContext().VoidPtrTy));
234         // sizeof (Type of Ivar)
235         uint64_t Size =  getContext().getTypeSize(Ivar->getType()) / 8;
236         llvm::Value *SizeVal =
237           llvm::ConstantInt::get(Types.ConvertType(getContext().LongTy), Size);
238         Args.push_back(std::make_pair(RValue::get(SizeVal),
239                                       getContext().LongTy));
240         llvm::Value *isAtomic =
241           llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy),
242                                  IsAtomic ? 1 : 0);
243         Args.push_back(std::make_pair(RValue::get(isAtomic),
244                                       getContext().BoolTy));
245         llvm::Value *hasStrong =
246           llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy),
247                                  IsStrong ? 1 : 0);
248         Args.push_back(std::make_pair(RValue::get(hasStrong),
249                                       getContext().BoolTy));
250         EmitCall(Types.getFunctionInfo(getContext().VoidTy, Args,
251                                        FunctionType::ExtInfo()),
252                  GetCopyStructFn, ReturnValueSlot(), Args);
253       }
254       else {
255         if (PID->getGetterCXXConstructor()) {
256           ReturnStmt *Stmt =
257             new (getContext()) ReturnStmt(SourceLocation(),
258                                           PID->getGetterCXXConstructor());
259           EmitReturnStmt(*Stmt);
260         }
261         else {
262           LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(),
263                                         Ivar, 0);
264           EmitAggregateCopy(ReturnValue, LV.getAddress(), Ivar->getType());
265         }
266       }
267     } else {
268       LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(),
269                                     Ivar, 0);
270       CodeGenTypes &Types = CGM.getTypes();
271       RValue RV = EmitLoadOfLValue(LV, Ivar->getType());
272       RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(),
273                        Types.ConvertType(PD->getType())));
274       EmitReturnOfRValue(RV, PD->getType());
275     }
276   }
277 
278   FinishFunction();
279 }
280 
281 /// GenerateObjCSetter - Generate an Objective-C property setter
282 /// function. The given Decl must be an ObjCImplementationDecl. @synthesize
283 /// is illegal within a category.
284 void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
285                                          const ObjCPropertyImplDecl *PID) {
286   ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
287   const ObjCPropertyDecl *PD = PID->getPropertyDecl();
288   ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
289   assert(OMD && "Invalid call to generate setter (empty method)");
290   StartObjCMethod(OMD, IMP->getClassInterface());
291 
292   bool IsCopy = PD->getSetterKind() == ObjCPropertyDecl::Copy;
293   bool IsAtomic =
294     !(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic);
295 
296   // Determine if we should use an objc_setProperty call for
297   // this. Properties with 'copy' semantics always use it, as do
298   // non-atomic properties with 'release' semantics as long as we are
299   // not in gc-only mode.
300   if (IsCopy ||
301       (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly &&
302        PD->getSetterKind() == ObjCPropertyDecl::Retain)) {
303     llvm::Value *SetPropertyFn =
304       CGM.getObjCRuntime().GetPropertySetFunction();
305 
306     if (!SetPropertyFn) {
307       CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy");
308       FinishFunction();
309       return;
310     }
311 
312     // Emit objc_setProperty((id) self, _cmd, offset, arg,
313     //                       <is-atomic>, <is-copy>).
314     // FIXME: Can't this be simpler? This might even be worse than the
315     // corresponding gcc code.
316     CodeGenTypes &Types = CGM.getTypes();
317     ValueDecl *Cmd = OMD->getCmdDecl();
318     llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd");
319     QualType IdTy = getContext().getObjCIdType();
320     llvm::Value *SelfAsId =
321       Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
322     llvm::Value *Offset = EmitIvarOffset(IMP->getClassInterface(), Ivar);
323     llvm::Value *Arg = LocalDeclMap[*OMD->param_begin()];
324     llvm::Value *ArgAsId =
325       Builder.CreateBitCast(Builder.CreateLoad(Arg, "arg"),
326                             Types.ConvertType(IdTy));
327     llvm::Value *True =
328       llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 1);
329     llvm::Value *False =
330       llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 0);
331     CallArgList Args;
332     Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy));
333     Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType()));
334     Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy));
335     Args.push_back(std::make_pair(RValue::get(ArgAsId), IdTy));
336     Args.push_back(std::make_pair(RValue::get(IsAtomic ? True : False),
337                                   getContext().BoolTy));
338     Args.push_back(std::make_pair(RValue::get(IsCopy ? True : False),
339                                   getContext().BoolTy));
340     // FIXME: We shouldn't need to get the function info here, the runtime
341     // already should have computed it to build the function.
342     EmitCall(Types.getFunctionInfo(getContext().VoidTy, Args,
343                                    FunctionType::ExtInfo()),
344              SetPropertyFn,
345              ReturnValueSlot(), Args);
346   } else if (IsAtomic && hasAggregateLLVMType(Ivar->getType()) &&
347              !Ivar->getType()->isAnyComplexType() &&
348              IndirectObjCSetterArg(*CurFnInfo)
349              && CGM.getObjCRuntime().GetCopyStructFunction()) {
350     // objc_copyStruct (&structIvar, &Arg,
351     //                  sizeof (struct something), true, false);
352     llvm::Value *GetCopyStructFn =
353       CGM.getObjCRuntime().GetCopyStructFunction();
354     CodeGenTypes &Types = CGM.getTypes();
355     CallArgList Args;
356     LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), Ivar, 0);
357     RValue RV = RValue::get(Builder.CreateBitCast(LV.getAddress(),
358                                     Types.ConvertType(getContext().VoidPtrTy)));
359     Args.push_back(std::make_pair(RV, getContext().VoidPtrTy));
360     llvm::Value *Arg = LocalDeclMap[*OMD->param_begin()];
361     llvm::Value *ArgAsPtrTy =
362       Builder.CreateBitCast(Arg,
363                             Types.ConvertType(getContext().VoidPtrTy));
364     RV = RValue::get(ArgAsPtrTy);
365     Args.push_back(std::make_pair(RV, getContext().VoidPtrTy));
366     // sizeof (Type of Ivar)
367     uint64_t Size =  getContext().getTypeSize(Ivar->getType()) / 8;
368     llvm::Value *SizeVal =
369       llvm::ConstantInt::get(Types.ConvertType(getContext().LongTy), Size);
370     Args.push_back(std::make_pair(RValue::get(SizeVal),
371                                   getContext().LongTy));
372     llvm::Value *True =
373       llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 1);
374     Args.push_back(std::make_pair(RValue::get(True), getContext().BoolTy));
375     llvm::Value *False =
376       llvm::ConstantInt::get(Types.ConvertType(getContext().BoolTy), 0);
377     Args.push_back(std::make_pair(RValue::get(False), getContext().BoolTy));
378     EmitCall(Types.getFunctionInfo(getContext().VoidTy, Args,
379                                    FunctionType::ExtInfo()),
380              GetCopyStructFn, ReturnValueSlot(), Args);
381   } else if (PID->getSetterCXXAssignment()) {
382     EmitAnyExpr(PID->getSetterCXXAssignment(), (llvm::Value *)0, false, true,
383                 false);
384 
385   } else {
386     // FIXME: Find a clean way to avoid AST node creation.
387     SourceLocation Loc = PD->getLocation();
388     ValueDecl *Self = OMD->getSelfDecl();
389     ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
390     DeclRefExpr Base(Self, Self->getType(), Loc);
391     ParmVarDecl *ArgDecl = *OMD->param_begin();
392     DeclRefExpr Arg(ArgDecl, ArgDecl->getType(), Loc);
393     ObjCIvarRefExpr IvarRef(Ivar, Ivar->getType(), Loc, &Base, true, true);
394 
395     // The property type can differ from the ivar type in some situations with
396     // Objective-C pointer types, we can always bit cast the RHS in these cases.
397     if (getContext().getCanonicalType(Ivar->getType()) !=
398         getContext().getCanonicalType(ArgDecl->getType())) {
399       ImplicitCastExpr ArgCasted(Ivar->getType(), CastExpr::CK_BitCast, &Arg,
400                                  CXXBaseSpecifierArray(), false);
401       BinaryOperator Assign(&IvarRef, &ArgCasted, BinaryOperator::Assign,
402                             Ivar->getType(), Loc);
403       EmitStmt(&Assign);
404     } else {
405       BinaryOperator Assign(&IvarRef, &Arg, BinaryOperator::Assign,
406                             Ivar->getType(), Loc);
407       EmitStmt(&Assign);
408     }
409   }
410 
411   FinishFunction();
412 }
413 
414 void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
415                                                  ObjCMethodDecl *MD,
416                                                  bool ctor) {
417   llvm::SmallVector<CXXBaseOrMemberInitializer *, 8> IvarInitializers;
418   MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface());
419   StartObjCMethod(MD, IMP->getClassInterface());
420   for (ObjCImplementationDecl::init_const_iterator B = IMP->init_begin(),
421        E = IMP->init_end(); B != E; ++B) {
422     CXXBaseOrMemberInitializer *Member = (*B);
423     IvarInitializers.push_back(Member);
424   }
425   if (ctor) {
426     for (unsigned I = 0, E = IvarInitializers.size(); I != E; ++I) {
427       CXXBaseOrMemberInitializer *IvarInit = IvarInitializers[I];
428       FieldDecl *Field = IvarInit->getMember();
429       QualType FieldType = Field->getType();
430       ObjCIvarDecl  *Ivar = cast<ObjCIvarDecl>(Field);
431       LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
432                                     LoadObjCSelf(), Ivar, 0);
433       EmitAggExpr(IvarInit->getInit(), LV.getAddress(),
434                   LV.isVolatileQualified(), false, true);
435     }
436     // constructor returns 'self'.
437     CodeGenTypes &Types = CGM.getTypes();
438     QualType IdTy(CGM.getContext().getObjCIdType());
439     llvm::Value *SelfAsId =
440       Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
441     EmitReturnOfRValue(RValue::get(SelfAsId), IdTy);
442   } else {
443     // dtor
444     for (size_t i = IvarInitializers.size(); i > 0; --i) {
445       FieldDecl *Field = IvarInitializers[i - 1]->getMember();
446       QualType FieldType = Field->getType();
447       const ConstantArrayType *Array =
448         getContext().getAsConstantArrayType(FieldType);
449       if (Array)
450         FieldType = getContext().getBaseElementType(FieldType);
451 
452       ObjCIvarDecl  *Ivar = cast<ObjCIvarDecl>(Field);
453       LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
454                                     LoadObjCSelf(), Ivar, 0);
455       const RecordType *RT = FieldType->getAs<RecordType>();
456       CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
457       CXXDestructorDecl *Dtor = FieldClassDecl->getDestructor(getContext());
458       if (!Dtor->isTrivial()) {
459         if (Array) {
460           const llvm::Type *BasePtr = ConvertType(FieldType);
461           BasePtr = llvm::PointerType::getUnqual(BasePtr);
462           llvm::Value *BaseAddrPtr =
463             Builder.CreateBitCast(LV.getAddress(), BasePtr);
464           EmitCXXAggrDestructorCall(Dtor,
465                                     Array, BaseAddrPtr);
466         } else {
467           EmitCXXDestructorCall(Dtor,
468                                 Dtor_Complete, /*ForVirtualBase=*/false,
469                                 LV.getAddress());
470         }
471       }
472     }
473   }
474   FinishFunction();
475 }
476 
477 bool CodeGenFunction::IndirectObjCSetterArg(const CGFunctionInfo &FI) {
478   CGFunctionInfo::const_arg_iterator it = FI.arg_begin();
479   it++; it++;
480   const ABIArgInfo &AI = it->info;
481   // FIXME. Is this sufficient check?
482   return (AI.getKind() == ABIArgInfo::Indirect);
483 }
484 
485 bool CodeGenFunction::IvarTypeWithAggrGCObjects(QualType Ty) {
486   if (CGM.getLangOptions().getGCMode() == LangOptions::NonGC)
487     return false;
488   if (const RecordType *FDTTy = Ty.getTypePtr()->getAs<RecordType>())
489     return FDTTy->getDecl()->hasObjectMember();
490   return false;
491 }
492 
493 llvm::Value *CodeGenFunction::LoadObjCSelf() {
494   const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
495   // See if we need to lazily forward self inside a block literal.
496   BlockForwardSelf();
497   return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self");
498 }
499 
500 QualType CodeGenFunction::TypeOfSelfObject() {
501   const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
502   ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
503   const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>(
504     getContext().getCanonicalType(selfDecl->getType()));
505   return PTy->getPointeeType();
506 }
507 
508 RValue CodeGenFunction::EmitObjCSuperPropertyGet(const Expr *Exp,
509                                                  const Selector &S) {
510   llvm::Value *Receiver = LoadObjCSelf();
511   const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
512   bool isClassMessage = OMD->isClassMethod();
513   bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
514   return CGM.getObjCRuntime().GenerateMessageSendSuper(*this,
515                                                        Exp->getType(),
516                                                        S,
517                                                        OMD->getClassInterface(),
518                                                        isCategoryImpl,
519                                                        Receiver,
520                                                        isClassMessage,
521                                                        CallArgList());
522 
523 }
524 
525 RValue CodeGenFunction::EmitObjCPropertyGet(const Expr *Exp) {
526   Exp = Exp->IgnoreParens();
527   // FIXME: Split it into two separate routines.
528   if (const ObjCPropertyRefExpr *E = dyn_cast<ObjCPropertyRefExpr>(Exp)) {
529     Selector S = E->getProperty()->getGetterName();
530     if (isa<ObjCSuperExpr>(E->getBase()))
531       return EmitObjCSuperPropertyGet(E, S);
532     return CGM.getObjCRuntime().
533              GenerateMessageSend(*this, Exp->getType(), S,
534                                  EmitScalarExpr(E->getBase()),
535                                  CallArgList());
536   } else {
537     const ObjCImplicitSetterGetterRefExpr *KE =
538       cast<ObjCImplicitSetterGetterRefExpr>(Exp);
539     Selector S = KE->getGetterMethod()->getSelector();
540     llvm::Value *Receiver;
541     if (KE->getInterfaceDecl()) {
542       const ObjCInterfaceDecl *OID = KE->getInterfaceDecl();
543       Receiver = CGM.getObjCRuntime().GetClass(Builder, OID);
544     } else if (isa<ObjCSuperExpr>(KE->getBase()))
545       return EmitObjCSuperPropertyGet(KE, S);
546     else
547       Receiver = EmitScalarExpr(KE->getBase());
548     return CGM.getObjCRuntime().
549              GenerateMessageSend(*this, Exp->getType(), S,
550                                  Receiver,
551                                  CallArgList(), KE->getInterfaceDecl());
552   }
553 }
554 
555 void CodeGenFunction::EmitObjCSuperPropertySet(const Expr *Exp,
556                                                const Selector &S,
557                                                RValue Src) {
558   CallArgList Args;
559   llvm::Value *Receiver = LoadObjCSelf();
560   const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
561   bool isClassMessage = OMD->isClassMethod();
562   bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
563   Args.push_back(std::make_pair(Src, Exp->getType()));
564   CGM.getObjCRuntime().GenerateMessageSendSuper(*this,
565                                                 Exp->getType(),
566                                                 S,
567                                                 OMD->getClassInterface(),
568                                                 isCategoryImpl,
569                                                 Receiver,
570                                                 isClassMessage,
571                                                 Args);
572   return;
573 }
574 
575 void CodeGenFunction::EmitObjCPropertySet(const Expr *Exp,
576                                           RValue Src) {
577   // FIXME: Split it into two separate routines.
578   if (const ObjCPropertyRefExpr *E = dyn_cast<ObjCPropertyRefExpr>(Exp)) {
579     Selector S = E->getProperty()->getSetterName();
580     if (isa<ObjCSuperExpr>(E->getBase())) {
581       EmitObjCSuperPropertySet(E, S, Src);
582       return;
583     }
584     CallArgList Args;
585     Args.push_back(std::make_pair(Src, E->getType()));
586     CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S,
587                                              EmitScalarExpr(E->getBase()),
588                                              Args);
589   } else if (const ObjCImplicitSetterGetterRefExpr *E =
590                dyn_cast<ObjCImplicitSetterGetterRefExpr>(Exp)) {
591     Selector S = E->getSetterMethod()->getSelector();
592     CallArgList Args;
593     llvm::Value *Receiver;
594     if (E->getInterfaceDecl()) {
595       const ObjCInterfaceDecl *OID = E->getInterfaceDecl();
596       Receiver = CGM.getObjCRuntime().GetClass(Builder, OID);
597     } else if (isa<ObjCSuperExpr>(E->getBase())) {
598       EmitObjCSuperPropertySet(E, S, Src);
599       return;
600     } else
601       Receiver = EmitScalarExpr(E->getBase());
602     Args.push_back(std::make_pair(Src, E->getType()));
603     CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S,
604                                              Receiver,
605                                              Args, E->getInterfaceDecl());
606   } else
607     assert (0 && "bad expression node in EmitObjCPropertySet");
608 }
609 
610 void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
611   llvm::Constant *EnumerationMutationFn =
612     CGM.getObjCRuntime().EnumerationMutationFunction();
613   llvm::Value *DeclAddress;
614   QualType ElementTy;
615 
616   if (!EnumerationMutationFn) {
617     CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
618     return;
619   }
620 
621   if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
622     EmitStmt(SD);
623     assert(HaveInsertPoint() && "DeclStmt destroyed insert point!");
624     const Decl* D = SD->getSingleDecl();
625     ElementTy = cast<ValueDecl>(D)->getType();
626     DeclAddress = LocalDeclMap[D];
627   } else {
628     ElementTy = cast<Expr>(S.getElement())->getType();
629     DeclAddress = 0;
630   }
631 
632   // Fast enumeration state.
633   QualType StateTy = getContext().getObjCFastEnumerationStateType();
634   llvm::Value *StatePtr = CreateMemTemp(StateTy, "state.ptr");
635   EmitMemSetToZero(StatePtr, StateTy);
636 
637   // Number of elements in the items array.
638   static const unsigned NumItems = 16;
639 
640   // Get selector
641   IdentifierInfo *II[] = {
642     &CGM.getContext().Idents.get("countByEnumeratingWithState"),
643     &CGM.getContext().Idents.get("objects"),
644     &CGM.getContext().Idents.get("count")
645   };
646   Selector FastEnumSel =
647     CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]);
648 
649   QualType ItemsTy =
650     getContext().getConstantArrayType(getContext().getObjCIdType(),
651                                       llvm::APInt(32, NumItems),
652                                       ArrayType::Normal, 0);
653   llvm::Value *ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
654 
655   llvm::Value *Collection = EmitScalarExpr(S.getCollection());
656 
657   CallArgList Args;
658   Args.push_back(std::make_pair(RValue::get(StatePtr),
659                                 getContext().getPointerType(StateTy)));
660 
661   Args.push_back(std::make_pair(RValue::get(ItemsPtr),
662                                 getContext().getPointerType(ItemsTy)));
663 
664   const llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy);
665   llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems);
666   Args.push_back(std::make_pair(RValue::get(Count),
667                                 getContext().UnsignedLongTy));
668 
669   RValue CountRV =
670     CGM.getObjCRuntime().GenerateMessageSend(*this,
671                                              getContext().UnsignedLongTy,
672                                              FastEnumSel,
673                                              Collection, Args);
674 
675   llvm::Value *LimitPtr = CreateMemTemp(getContext().UnsignedLongTy,
676                                         "limit.ptr");
677   Builder.CreateStore(CountRV.getScalarVal(), LimitPtr);
678 
679   llvm::BasicBlock *NoElements = createBasicBlock("noelements");
680   llvm::BasicBlock *SetStartMutations = createBasicBlock("setstartmutations");
681 
682   llvm::Value *Limit = Builder.CreateLoad(LimitPtr);
683   llvm::Value *Zero = llvm::Constant::getNullValue(UnsignedLongLTy);
684 
685   llvm::Value *IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero");
686   Builder.CreateCondBr(IsZero, NoElements, SetStartMutations);
687 
688   EmitBlock(SetStartMutations);
689 
690   llvm::Value *StartMutationsPtr = CreateMemTemp(getContext().UnsignedLongTy);
691 
692   llvm::Value *StateMutationsPtrPtr =
693     Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
694   llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr,
695                                                       "mutationsptr");
696 
697   llvm::Value *StateMutations = Builder.CreateLoad(StateMutationsPtr,
698                                                    "mutations");
699 
700   Builder.CreateStore(StateMutations, StartMutationsPtr);
701 
702   llvm::BasicBlock *LoopStart = createBasicBlock("loopstart");
703   EmitBlock(LoopStart);
704 
705   llvm::Value *CounterPtr = CreateMemTemp(getContext().UnsignedLongTy,
706                                        "counter.ptr");
707   Builder.CreateStore(Zero, CounterPtr);
708 
709   llvm::BasicBlock *LoopBody = createBasicBlock("loopbody");
710   EmitBlock(LoopBody);
711 
712   StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
713   StateMutations = Builder.CreateLoad(StateMutationsPtr, "statemutations");
714 
715   llvm::Value *StartMutations = Builder.CreateLoad(StartMutationsPtr,
716                                                    "mutations");
717   llvm::Value *MutationsEqual = Builder.CreateICmpEQ(StateMutations,
718                                                      StartMutations,
719                                                      "tobool");
720 
721 
722   llvm::BasicBlock *WasMutated = createBasicBlock("wasmutated");
723   llvm::BasicBlock *WasNotMutated = createBasicBlock("wasnotmutated");
724 
725   Builder.CreateCondBr(MutationsEqual, WasNotMutated, WasMutated);
726 
727   EmitBlock(WasMutated);
728   llvm::Value *V =
729     Builder.CreateBitCast(Collection,
730                           ConvertType(getContext().getObjCIdType()),
731                           "tmp");
732   CallArgList Args2;
733   Args2.push_back(std::make_pair(RValue::get(V),
734                                 getContext().getObjCIdType()));
735   // FIXME: We shouldn't need to get the function info here, the runtime already
736   // should have computed it to build the function.
737   EmitCall(CGM.getTypes().getFunctionInfo(getContext().VoidTy, Args2,
738                                           FunctionType::ExtInfo()),
739            EnumerationMutationFn, ReturnValueSlot(), Args2);
740 
741   EmitBlock(WasNotMutated);
742 
743   llvm::Value *StateItemsPtr =
744     Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
745 
746   llvm::Value *Counter = Builder.CreateLoad(CounterPtr, "counter");
747 
748   llvm::Value *EnumStateItems = Builder.CreateLoad(StateItemsPtr,
749                                                    "stateitems");
750 
751   llvm::Value *CurrentItemPtr =
752     Builder.CreateGEP(EnumStateItems, Counter, "currentitem.ptr");
753 
754   llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr, "currentitem");
755 
756   // Cast the item to the right type.
757   CurrentItem = Builder.CreateBitCast(CurrentItem,
758                                       ConvertType(ElementTy), "tmp");
759 
760   if (!DeclAddress) {
761     LValue LV = EmitLValue(cast<Expr>(S.getElement()));
762 
763     // Set the value to null.
764     Builder.CreateStore(CurrentItem, LV.getAddress());
765   } else
766     Builder.CreateStore(CurrentItem, DeclAddress);
767 
768   // Increment the counter.
769   Counter = Builder.CreateAdd(Counter,
770                               llvm::ConstantInt::get(UnsignedLongLTy, 1));
771   Builder.CreateStore(Counter, CounterPtr);
772 
773   llvm::BasicBlock *LoopEnd = createBasicBlock("loopend");
774   llvm::BasicBlock *AfterBody = createBasicBlock("afterbody");
775 
776   BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
777 
778   EmitStmt(S.getBody());
779 
780   BreakContinueStack.pop_back();
781 
782   EmitBlock(AfterBody);
783 
784   llvm::BasicBlock *FetchMore = createBasicBlock("fetchmore");
785 
786   Counter = Builder.CreateLoad(CounterPtr);
787   Limit = Builder.CreateLoad(LimitPtr);
788   llvm::Value *IsLess = Builder.CreateICmpULT(Counter, Limit, "isless");
789   Builder.CreateCondBr(IsLess, LoopBody, FetchMore);
790 
791   // Fetch more elements.
792   EmitBlock(FetchMore);
793 
794   CountRV =
795     CGM.getObjCRuntime().GenerateMessageSend(*this,
796                                              getContext().UnsignedLongTy,
797                                              FastEnumSel,
798                                              Collection, Args);
799   Builder.CreateStore(CountRV.getScalarVal(), LimitPtr);
800   Limit = Builder.CreateLoad(LimitPtr);
801 
802   IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero");
803   Builder.CreateCondBr(IsZero, NoElements, LoopStart);
804 
805   // No more elements.
806   EmitBlock(NoElements);
807 
808   if (!DeclAddress) {
809     // If the element was not a declaration, set it to be null.
810 
811     LValue LV = EmitLValue(cast<Expr>(S.getElement()));
812 
813     // Set the value to null.
814     Builder.CreateStore(llvm::Constant::getNullValue(ConvertType(ElementTy)),
815                         LV.getAddress());
816   }
817 
818   EmitBlock(LoopEnd);
819 }
820 
821 void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) {
822   CGM.getObjCRuntime().EmitTryOrSynchronizedStmt(*this, S);
823 }
824 
825 void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) {
826   CGM.getObjCRuntime().EmitThrowStmt(*this, S);
827 }
828 
829 void CodeGenFunction::EmitObjCAtSynchronizedStmt(
830                                               const ObjCAtSynchronizedStmt &S) {
831   CGM.getObjCRuntime().EmitTryOrSynchronizedStmt(*this, S);
832 }
833 
834 CGObjCRuntime::~CGObjCRuntime() {}
835