//===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This contains code to emit Objective-C code as LLVM code. // //===----------------------------------------------------------------------===// #include "CGObjCRuntime.h" #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "clang/Basic/Diagnostic.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Target/TargetData.h" using namespace clang; using namespace CodeGen; /// Emits an instance of NSConstantString representing the object. llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E) { std::string String(E->getString()->getStrData(), E->getString()->getByteLength()); llvm::Constant *C = CGM.getObjCRuntime().GenerateConstantString(String); // FIXME: This bitcast should just be made an invariant on the Runtime. return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType())); } /// Emit a selector. llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) { // Untyped selector. // Note that this implementation allows for non-constant strings to be passed // as arguments to @selector(). Currently, the only thing preventing this // behaviour is the type checking in the front end. return CGM.getObjCRuntime().GetSelector(Builder, E->getSelector()); } llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) { // FIXME: This should pass the Decl not the name. return CGM.getObjCRuntime().GenerateProtocolRef(Builder, E->getProtocol()); } RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E) { // Only the lookup mechanism and first two arguments of the method // implementation vary between runtimes. We can get the receiver and // arguments in generic code. CGObjCRuntime &Runtime = CGM.getObjCRuntime(); const Expr *ReceiverExpr = E->getReceiver(); bool isSuperMessage = false; bool isClassMessage = false; // Find the receiver llvm::Value *Receiver; if (!ReceiverExpr) { const ObjCInterfaceDecl *OID = E->getClassInfo().first; // Very special case, super send in class method. The receiver is // self (the class object) and the send uses super semantics. if (!OID) { assert(E->getClassName()->isStr("super") && "Unexpected missing class interface in message send."); isSuperMessage = true; Receiver = LoadObjCSelf(); } else { Receiver = Runtime.GetClass(Builder, OID); } isClassMessage = true; } else if (isa(E->getReceiver())) { isSuperMessage = true; Receiver = LoadObjCSelf(); } else { Receiver = EmitScalarExpr(E->getReceiver()); } CallArgList Args; for (CallExpr::const_arg_iterator i = E->arg_begin(), e = E->arg_end(); i != e; ++i) Args.push_back(std::make_pair(EmitAnyExprToTemp(*i), (*i)->getType())); if (isSuperMessage) { // super is only valid in an Objective-C method const ObjCMethodDecl *OMD = cast(CurFuncDecl); return Runtime.GenerateMessageSendSuper(*this, E->getType(), E->getSelector(), OMD->getClassInterface(), Receiver, isClassMessage, Args); } return Runtime.GenerateMessageSend(*this, E->getType(), E->getSelector(), Receiver, isClassMessage, Args); } /// StartObjCMethod - Begin emission of an ObjCMethod. This generates /// the LLVM function and sets the other context used by /// CodeGenFunction. void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD, const ObjCContainerDecl *CD) { FunctionArgList Args; llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD); CGM.SetMethodAttributes(OMD, Fn); Args.push_back(std::make_pair(OMD->getSelfDecl(), OMD->getSelfDecl()->getType())); Args.push_back(std::make_pair(OMD->getCmdDecl(), OMD->getCmdDecl()->getType())); for (unsigned i = 0, e = OMD->getNumParams(); i != e; ++i) { ParmVarDecl *IPD = OMD->getParamDecl(i); Args.push_back(std::make_pair(IPD, IPD->getType())); } StartFunction(OMD, OMD->getResultType(), Fn, Args, OMD->getLocEnd()); } /// Generate an Objective-C method. An Objective-C method is a C function with /// its pointer, name, and types registered in the class struture. void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) { StartObjCMethod(OMD, OMD->getClassInterface()); EmitStmt(OMD->getBody()); FinishFunction(cast(OMD->getBody())->getRBracLoc()); } // FIXME: I wasn't sure about the synthesis approach. If we end up // generating an AST for the whole body we can just fall back to // having a GenerateFunction which takes the body Stmt. /// GenerateObjCGetter - Generate an Objective-C property getter /// function. The given Decl must be an ObjCImplementationDecl. @synthesize /// is illegal within a category. void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP, const ObjCPropertyImplDecl *PID) { ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl(); const ObjCPropertyDecl *PD = PID->getPropertyDecl(); ObjCMethodDecl *OMD = PD->getGetterMethodDecl(); assert(OMD && "Invalid call to generate getter (empty method)"); // FIXME: This is rather murky, we create this here since they will // not have been created by Sema for us. OMD->createImplicitParams(getContext(), IMP->getClassInterface()); StartObjCMethod(OMD, IMP->getClassInterface()); // Determine if we should use an objc_getProperty call for // this. Non-atomic properties are directly evaluated. // atomic 'copy' and 'retain' properties are also directly // evaluated in gc-only mode. if (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly && !(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic) && (PD->getSetterKind() == ObjCPropertyDecl::Copy || PD->getSetterKind() == ObjCPropertyDecl::Retain)) { llvm::Value *GetPropertyFn = CGM.getObjCRuntime().GetPropertyGetFunction(); if (!GetPropertyFn) { CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy"); FinishFunction(); return; } // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true). // FIXME: Can't this be simpler? This might even be worse than the // corresponding gcc code. CodeGenTypes &Types = CGM.getTypes(); ValueDecl *Cmd = OMD->getCmdDecl(); llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd"); QualType IdTy = getContext().getObjCIdType(); llvm::Value *SelfAsId = Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy)); llvm::Value *Offset = EmitIvarOffset(IMP->getClassInterface(), Ivar); llvm::Value *True = llvm::ConstantInt::get(Types.ConvertTypeForMem(getContext().BoolTy), 1); CallArgList Args; Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy)); Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType())); Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy)); Args.push_back(std::make_pair(RValue::get(True), getContext().BoolTy)); RValue RV = EmitCall(CGFunctionInfo(PD->getType(), Args), GetPropertyFn, Args); // We need to fix the type here. Ivars with copy & retain are // always objects so we don't need to worry about complex or // aggregates. RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(), Types.ConvertType(PD->getType()))); EmitReturnOfRValue(RV, PD->getType()); } else { FieldDecl *Field = IMP->getClassInterface()->lookupFieldDeclForIvar(getContext(), Ivar); LValue LV = EmitLValueForIvar(LoadObjCSelf(), Ivar, Field, 0); if (hasAggregateLLVMType(Ivar->getType())) { EmitAggregateCopy(ReturnValue, LV.getAddress(), Ivar->getType()); } else EmitReturnOfRValue(EmitLoadOfLValue(LV, Ivar->getType()), PD->getType()); } FinishFunction(); } /// GenerateObjCSetter - Generate an Objective-C property setter /// function. The given Decl must be an ObjCImplementationDecl. @synthesize /// is illegal within a category. void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP, const ObjCPropertyImplDecl *PID) { ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl(); const ObjCPropertyDecl *PD = PID->getPropertyDecl(); ObjCMethodDecl *OMD = PD->getSetterMethodDecl(); assert(OMD && "Invalid call to generate setter (empty method)"); // FIXME: This is rather murky, we create this here since they will // not have been created by Sema for us. OMD->createImplicitParams(getContext(), IMP->getClassInterface()); StartObjCMethod(OMD, IMP->getClassInterface()); bool IsCopy = PD->getSetterKind() == ObjCPropertyDecl::Copy; bool IsAtomic = !(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic); // Determine if we should use an objc_setProperty call for // this. Properties with 'copy' semantics always use it, as do // non-atomic properties with 'release' semantics as long as we are // not in gc-only mode. if (IsCopy || (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly && PD->getSetterKind() == ObjCPropertyDecl::Retain)) { llvm::Value *SetPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction(); if (!SetPropertyFn) { CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy"); FinishFunction(); return; } // Emit objc_setProperty((id) self, _cmd, offset, arg, // , ). // FIXME: Can't this be simpler? This might even be worse than the // corresponding gcc code. CodeGenTypes &Types = CGM.getTypes(); ValueDecl *Cmd = OMD->getCmdDecl(); llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd"); QualType IdTy = getContext().getObjCIdType(); llvm::Value *SelfAsId = Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy)); llvm::Value *Offset = EmitIvarOffset(IMP->getClassInterface(), Ivar); llvm::Value *Arg = LocalDeclMap[OMD->getParamDecl(0)]; llvm::Value *ArgAsId = Builder.CreateBitCast(Builder.CreateLoad(Arg, "arg"), Types.ConvertType(IdTy)); llvm::Value *True = llvm::ConstantInt::get(Types.ConvertTypeForMem(getContext().BoolTy), 1); llvm::Value *False = llvm::ConstantInt::get(Types.ConvertTypeForMem(getContext().BoolTy), 0); CallArgList Args; Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy)); Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType())); Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy)); Args.push_back(std::make_pair(RValue::get(ArgAsId), IdTy)); Args.push_back(std::make_pair(RValue::get(IsAtomic ? True : False), getContext().BoolTy)); Args.push_back(std::make_pair(RValue::get(IsCopy ? True : False), getContext().BoolTy)); EmitCall(CGFunctionInfo(PD->getType(), Args), SetPropertyFn, Args); } else { SourceLocation Loc = PD->getLocation(); ValueDecl *Self = OMD->getSelfDecl(); ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl(); DeclRefExpr Base(Self, Self->getType(), Loc); ParmVarDecl *ArgDecl = OMD->getParamDecl(0); DeclRefExpr Arg(ArgDecl, ArgDecl->getType(), Loc); ObjCInterfaceDecl *OI = IMP->getClassInterface(); ObjCIvarRefExpr IvarRef(Ivar, Ivar->getType(), Loc, &Base, true, true); getContext().setFieldDecl(OI, Ivar, &IvarRef); BinaryOperator Assign(&IvarRef, &Arg, BinaryOperator::Assign, Ivar->getType(), Loc); EmitStmt(&Assign); } FinishFunction(); } llvm::Value *CodeGenFunction::LoadObjCSelf() { const ObjCMethodDecl *OMD = cast(CurFuncDecl); return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self"); } RValue CodeGenFunction::EmitObjCPropertyGet(const Expr *Exp) { // FIXME: Split it into two separate routines. if (const ObjCPropertyRefExpr *E = dyn_cast(Exp)) { Selector S = E->getProperty()->getGetterName(); return CGM.getObjCRuntime(). GenerateMessageSend(*this, Exp->getType(), S, EmitScalarExpr(E->getBase()), false, CallArgList()); } else { const ObjCKVCRefExpr *KE = cast(Exp); Selector S = KE->getGetterMethod()->getSelector(); return CGM.getObjCRuntime(). GenerateMessageSend(*this, Exp->getType(), S, EmitScalarExpr(KE->getBase()), false, CallArgList()); } } void CodeGenFunction::EmitObjCPropertySet(const Expr *Exp, RValue Src) { // FIXME: Split it into two separate routines. if (const ObjCPropertyRefExpr *E = dyn_cast(Exp)) { Selector S = E->getProperty()->getSetterName(); CallArgList Args; Args.push_back(std::make_pair(Src, E->getType())); CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S, EmitScalarExpr(E->getBase()), false, Args); } else if (const ObjCKVCRefExpr *E = dyn_cast(Exp)) { Selector S = E->getSetterMethod()->getSelector(); CallArgList Args; Args.push_back(std::make_pair(Src, E->getType())); CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S, EmitScalarExpr(E->getBase()), false, Args); } else assert (0 && "bad expression node in EmitObjCPropertySet"); } void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S) { llvm::Function *EnumerationMutationFn = CGM.getObjCRuntime().EnumerationMutationFunction(); llvm::Value *DeclAddress; QualType ElementTy; if (!EnumerationMutationFn) { CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime"); return; } if (const DeclStmt *SD = dyn_cast(S.getElement())) { EmitStmt(SD); assert(HaveInsertPoint() && "DeclStmt destroyed insert point!"); const Decl* D = SD->getSolitaryDecl(); ElementTy = cast(D)->getType(); DeclAddress = LocalDeclMap[D]; } else { ElementTy = cast(S.getElement())->getType(); DeclAddress = 0; } // Fast enumeration state. QualType StateTy = getContext().getObjCFastEnumerationStateType(); llvm::AllocaInst *StatePtr = CreateTempAlloca(ConvertType(StateTy), "state.ptr"); StatePtr->setAlignment(getContext().getTypeAlign(StateTy) >> 3); EmitMemSetToZero(StatePtr, StateTy); // Number of elements in the items array. static const unsigned NumItems = 16; // Get selector llvm::SmallVector II; II.push_back(&CGM.getContext().Idents.get("countByEnumeratingWithState")); II.push_back(&CGM.getContext().Idents.get("objects")); II.push_back(&CGM.getContext().Idents.get("count")); Selector FastEnumSel = CGM.getContext().Selectors.getSelector(II.size(), &II[0]); QualType ItemsTy = getContext().getConstantArrayType(getContext().getObjCIdType(), llvm::APInt(32, NumItems), ArrayType::Normal, 0); llvm::Value *ItemsPtr = CreateTempAlloca(ConvertType(ItemsTy), "items.ptr"); llvm::Value *Collection = EmitScalarExpr(S.getCollection()); CallArgList Args; Args.push_back(std::make_pair(RValue::get(StatePtr), getContext().getPointerType(StateTy))); Args.push_back(std::make_pair(RValue::get(ItemsPtr), getContext().getPointerType(ItemsTy))); const llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy); llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems); Args.push_back(std::make_pair(RValue::get(Count), getContext().UnsignedLongTy)); RValue CountRV = CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().UnsignedLongTy, FastEnumSel, Collection, false, Args); llvm::Value *LimitPtr = CreateTempAlloca(UnsignedLongLTy, "limit.ptr"); Builder.CreateStore(CountRV.getScalarVal(), LimitPtr); llvm::BasicBlock *NoElements = createBasicBlock("noelements"); llvm::BasicBlock *SetStartMutations = createBasicBlock("setstartmutations"); llvm::Value *Limit = Builder.CreateLoad(LimitPtr); llvm::Value *Zero = llvm::Constant::getNullValue(UnsignedLongLTy); llvm::Value *IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero"); Builder.CreateCondBr(IsZero, NoElements, SetStartMutations); EmitBlock(SetStartMutations); llvm::Value *StartMutationsPtr = CreateTempAlloca(UnsignedLongLTy); llvm::Value *StateMutationsPtrPtr = Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr"); llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr"); llvm::Value *StateMutations = Builder.CreateLoad(StateMutationsPtr, "mutations"); Builder.CreateStore(StateMutations, StartMutationsPtr); llvm::BasicBlock *LoopStart = createBasicBlock("loopstart"); EmitBlock(LoopStart); llvm::Value *CounterPtr = CreateTempAlloca(UnsignedLongLTy, "counter.ptr"); Builder.CreateStore(Zero, CounterPtr); llvm::BasicBlock *LoopBody = createBasicBlock("loopbody"); EmitBlock(LoopBody); StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr"); StateMutations = Builder.CreateLoad(StateMutationsPtr, "statemutations"); llvm::Value *StartMutations = Builder.CreateLoad(StartMutationsPtr, "mutations"); llvm::Value *MutationsEqual = Builder.CreateICmpEQ(StateMutations, StartMutations, "tobool"); llvm::BasicBlock *WasMutated = createBasicBlock("wasmutated"); llvm::BasicBlock *WasNotMutated = createBasicBlock("wasnotmutated"); Builder.CreateCondBr(MutationsEqual, WasNotMutated, WasMutated); EmitBlock(WasMutated); llvm::Value *V = Builder.CreateBitCast(Collection, ConvertType(getContext().getObjCIdType()), "tmp"); Builder.CreateCall(EnumerationMutationFn, V); EmitBlock(WasNotMutated); llvm::Value *StateItemsPtr = Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr"); llvm::Value *Counter = Builder.CreateLoad(CounterPtr, "counter"); llvm::Value *EnumStateItems = Builder.CreateLoad(StateItemsPtr, "stateitems"); llvm::Value *CurrentItemPtr = Builder.CreateGEP(EnumStateItems, Counter, "currentitem.ptr"); llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr, "currentitem"); // Cast the item to the right type. CurrentItem = Builder.CreateBitCast(CurrentItem, ConvertType(ElementTy), "tmp"); if (!DeclAddress) { LValue LV = EmitLValue(cast(S.getElement())); // Set the value to null. Builder.CreateStore(CurrentItem, LV.getAddress()); } else Builder.CreateStore(CurrentItem, DeclAddress); // Increment the counter. Counter = Builder.CreateAdd(Counter, llvm::ConstantInt::get(UnsignedLongLTy, 1)); Builder.CreateStore(Counter, CounterPtr); llvm::BasicBlock *LoopEnd = createBasicBlock("loopend"); llvm::BasicBlock *AfterBody = createBasicBlock("afterbody"); BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody, ObjCEHStack.size())); EmitStmt(S.getBody()); BreakContinueStack.pop_back(); EmitBlock(AfterBody); llvm::BasicBlock *FetchMore = createBasicBlock("fetchmore"); Counter = Builder.CreateLoad(CounterPtr); Limit = Builder.CreateLoad(LimitPtr); llvm::Value *IsLess = Builder.CreateICmpULT(Counter, Limit, "isless"); Builder.CreateCondBr(IsLess, LoopBody, FetchMore); // Fetch more elements. EmitBlock(FetchMore); CountRV = CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().UnsignedLongTy, FastEnumSel, Collection, false, Args); Builder.CreateStore(CountRV.getScalarVal(), LimitPtr); Limit = Builder.CreateLoad(LimitPtr); IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero"); Builder.CreateCondBr(IsZero, NoElements, LoopStart); // No more elements. EmitBlock(NoElements); if (!DeclAddress) { // If the element was not a declaration, set it to be null. LValue LV = EmitLValue(cast(S.getElement())); // Set the value to null. Builder.CreateStore(llvm::Constant::getNullValue(ConvertType(ElementTy)), LV.getAddress()); } EmitBlock(LoopEnd); } void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) { CGM.getObjCRuntime().EmitTryOrSynchronizedStmt(*this, S); } void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) { CGM.getObjCRuntime().EmitThrowStmt(*this, S); } void CodeGenFunction::EmitObjCAtSynchronizedStmt( const ObjCAtSynchronizedStmt &S) { CGM.getObjCRuntime().EmitTryOrSynchronizedStmt(*this, S); } CGObjCRuntime::~CGObjCRuntime() {}