//===---- 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 "CGDebugInfo.h" #include "CGObjCRuntime.h" #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "TargetInfo.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/StmtObjC.h" #include "clang/Basic/Diagnostic.h" #include "clang/CodeGen/CGFunctionInfo.h" #include "llvm/ADT/STLExtras.h" #include "llvm/IR/CallSite.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/InlineAsm.h" using namespace clang; using namespace CodeGen; typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult; static TryEmitResult tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e); static RValue AdjustObjCObjectType(CodeGenFunction &CGF, QualType ET, RValue Result); /// Given the address of a variable of pointer type, find the correct /// null to store into it. static llvm::Constant *getNullForVariable(Address addr) { llvm::Type *type = addr.getElementType(); return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(type)); } /// Emits an instance of NSConstantString representing the object. llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E) { llvm::Constant *C = CGM.getObjCRuntime().GenerateConstantString(E->getString()).getPointer(); // FIXME: This bitcast should just be made an invariant on the Runtime. return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType())); } /// EmitObjCBoxedExpr - This routine generates code to call /// the appropriate expression boxing method. This will either be /// one of +[NSNumber numberWith<Type>:], or +[NSString stringWithUTF8String:], /// or [NSValue valueWithBytes:objCType:]. /// llvm::Value * CodeGenFunction::EmitObjCBoxedExpr(const ObjCBoxedExpr *E) { // Generate the correct selector for this literal's concrete type. // Get the method. const ObjCMethodDecl *BoxingMethod = E->getBoxingMethod(); const Expr *SubExpr = E->getSubExpr(); assert(BoxingMethod && "BoxingMethod is null"); assert(BoxingMethod->isClassMethod() && "BoxingMethod must be a class method"); Selector Sel = BoxingMethod->getSelector(); // Generate a reference to the class pointer, which will be the receiver. // Assumes that the method was introduced in the class that should be // messaged (avoids pulling it out of the result type). CGObjCRuntime &Runtime = CGM.getObjCRuntime(); const ObjCInterfaceDecl *ClassDecl = BoxingMethod->getClassInterface(); llvm::Value *Receiver = Runtime.GetClass(*this, ClassDecl); CallArgList Args; const ParmVarDecl *ArgDecl = *BoxingMethod->param_begin(); QualType ArgQT = ArgDecl->getType().getUnqualifiedType(); // ObjCBoxedExpr supports boxing of structs and unions // via [NSValue valueWithBytes:objCType:] const QualType ValueType(SubExpr->getType().getCanonicalType()); if (ValueType->isObjCBoxableRecordType()) { // Emit CodeGen for first parameter // and cast value to correct type Address Temporary = CreateMemTemp(SubExpr->getType()); EmitAnyExprToMem(SubExpr, Temporary, Qualifiers(), /*isInit*/ true); Address BitCast = Builder.CreateBitCast(Temporary, ConvertType(ArgQT)); Args.add(RValue::get(BitCast.getPointer()), ArgQT); // Create char array to store type encoding std::string Str; getContext().getObjCEncodingForType(ValueType, Str); llvm::Constant *GV = CGM.GetAddrOfConstantCString(Str).getPointer(); // Cast type encoding to correct type const ParmVarDecl *EncodingDecl = BoxingMethod->parameters()[1]; QualType EncodingQT = EncodingDecl->getType().getUnqualifiedType(); llvm::Value *Cast = Builder.CreateBitCast(GV, ConvertType(EncodingQT)); Args.add(RValue::get(Cast), EncodingQT); } else { Args.add(EmitAnyExpr(SubExpr), ArgQT); } RValue result = Runtime.GenerateMessageSend( *this, ReturnValueSlot(), BoxingMethod->getReturnType(), Sel, Receiver, Args, ClassDecl, BoxingMethod); return Builder.CreateBitCast(result.getScalarVal(), ConvertType(E->getType())); } llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E, const ObjCMethodDecl *MethodWithObjects) { ASTContext &Context = CGM.getContext(); const ObjCDictionaryLiteral *DLE = nullptr; const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E); if (!ALE) DLE = cast<ObjCDictionaryLiteral>(E); // Compute the type of the array we're initializing. uint64_t NumElements = ALE ? ALE->getNumElements() : DLE->getNumElements(); llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()), NumElements); QualType ElementType = Context.getObjCIdType().withConst(); QualType ElementArrayType = Context.getConstantArrayType(ElementType, APNumElements, ArrayType::Normal, /*IndexTypeQuals=*/0); // Allocate the temporary array(s). Address Objects = CreateMemTemp(ElementArrayType, "objects"); Address Keys = Address::invalid(); if (DLE) Keys = CreateMemTemp(ElementArrayType, "keys"); // In ARC, we may need to do extra work to keep all the keys and // values alive until after the call. SmallVector<llvm::Value *, 16> NeededObjects; bool TrackNeededObjects = (getLangOpts().ObjCAutoRefCount && CGM.getCodeGenOpts().OptimizationLevel != 0); // Perform the actual initialialization of the array(s). for (uint64_t i = 0; i < NumElements; i++) { if (ALE) { // Emit the element and store it to the appropriate array slot. const Expr *Rhs = ALE->getElement(i); LValue LV = MakeAddrLValue( Builder.CreateConstArrayGEP(Objects, i, getPointerSize()), ElementType, AlignmentSource::Decl); llvm::Value *value = EmitScalarExpr(Rhs); EmitStoreThroughLValue(RValue::get(value), LV, true); if (TrackNeededObjects) { NeededObjects.push_back(value); } } else { // Emit the key and store it to the appropriate array slot. const Expr *Key = DLE->getKeyValueElement(i).Key; LValue KeyLV = MakeAddrLValue( Builder.CreateConstArrayGEP(Keys, i, getPointerSize()), ElementType, AlignmentSource::Decl); llvm::Value *keyValue = EmitScalarExpr(Key); EmitStoreThroughLValue(RValue::get(keyValue), KeyLV, /*isInit=*/true); // Emit the value and store it to the appropriate array slot. const Expr *Value = DLE->getKeyValueElement(i).Value; LValue ValueLV = MakeAddrLValue( Builder.CreateConstArrayGEP(Objects, i, getPointerSize()), ElementType, AlignmentSource::Decl); llvm::Value *valueValue = EmitScalarExpr(Value); EmitStoreThroughLValue(RValue::get(valueValue), ValueLV, /*isInit=*/true); if (TrackNeededObjects) { NeededObjects.push_back(keyValue); NeededObjects.push_back(valueValue); } } } // Generate the argument list. CallArgList Args; ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin(); const ParmVarDecl *argDecl = *PI++; QualType ArgQT = argDecl->getType().getUnqualifiedType(); Args.add(RValue::get(Objects.getPointer()), ArgQT); if (DLE) { argDecl = *PI++; ArgQT = argDecl->getType().getUnqualifiedType(); Args.add(RValue::get(Keys.getPointer()), ArgQT); } argDecl = *PI; ArgQT = argDecl->getType().getUnqualifiedType(); llvm::Value *Count = llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements); Args.add(RValue::get(Count), ArgQT); // Generate a reference to the class pointer, which will be the receiver. Selector Sel = MethodWithObjects->getSelector(); QualType ResultType = E->getType(); const ObjCObjectPointerType *InterfacePointerType = ResultType->getAsObjCInterfacePointerType(); ObjCInterfaceDecl *Class = InterfacePointerType->getObjectType()->getInterface(); CGObjCRuntime &Runtime = CGM.getObjCRuntime(); llvm::Value *Receiver = Runtime.GetClass(*this, Class); // Generate the message send. RValue result = Runtime.GenerateMessageSend( *this, ReturnValueSlot(), MethodWithObjects->getReturnType(), Sel, Receiver, Args, Class, MethodWithObjects); // The above message send needs these objects, but in ARC they are // passed in a buffer that is essentially __unsafe_unretained. // Therefore we must prevent the optimizer from releasing them until // after the call. if (TrackNeededObjects) { EmitARCIntrinsicUse(NeededObjects); } return Builder.CreateBitCast(result.getScalarVal(), ConvertType(E->getType())); } llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) { return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod()); } llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral( const ObjCDictionaryLiteral *E) { return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod()); } /// 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(*this, E->getSelector()); } llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) { // FIXME: This should pass the Decl not the name. return CGM.getObjCRuntime().GenerateProtocolRef(*this, E->getProtocol()); } /// \brief Adjust the type of an Objective-C object that doesn't match up due /// to type erasure at various points, e.g., related result types or the use /// of parameterized classes. static RValue AdjustObjCObjectType(CodeGenFunction &CGF, QualType ExpT, RValue Result) { if (!ExpT->isObjCRetainableType()) return Result; // If the converted types are the same, we're done. llvm::Type *ExpLLVMTy = CGF.ConvertType(ExpT); if (ExpLLVMTy == Result.getScalarVal()->getType()) return Result; // We have applied a substitution. Cast the rvalue appropriately. return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(), ExpLLVMTy)); } /// Decide whether to extend the lifetime of the receiver of a /// returns-inner-pointer message. static bool shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) { switch (message->getReceiverKind()) { // For a normal instance message, we should extend unless the // receiver is loaded from a variable with precise lifetime. case ObjCMessageExpr::Instance: { const Expr *receiver = message->getInstanceReceiver(); // Look through OVEs. if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) { if (opaque->getSourceExpr()) receiver = opaque->getSourceExpr()->IgnoreParens(); } const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver); if (!ice || ice->getCastKind() != CK_LValueToRValue) return true; receiver = ice->getSubExpr()->IgnoreParens(); // Look through OVEs. if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) { if (opaque->getSourceExpr()) receiver = opaque->getSourceExpr()->IgnoreParens(); } // Only __strong variables. if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong) return true; // All ivars and fields have precise lifetime. if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver)) return false; // Otherwise, check for variables. const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr()); if (!declRef) return true; const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl()); if (!var) return true; // All variables have precise lifetime except local variables with // automatic storage duration that aren't specially marked. return (var->hasLocalStorage() && !var->hasAttr<ObjCPreciseLifetimeAttr>()); } case ObjCMessageExpr::Class: case ObjCMessageExpr::SuperClass: // It's never necessary for class objects. return false; case ObjCMessageExpr::SuperInstance: // We generally assume that 'self' lives throughout a method call. return false; } llvm_unreachable("invalid receiver kind"); } /// Given an expression of ObjC pointer type, check whether it was /// immediately loaded from an ARC __weak l-value. static const Expr *findWeakLValue(const Expr *E) { assert(E->getType()->isObjCRetainableType()); E = E->IgnoreParens(); if (auto CE = dyn_cast<CastExpr>(E)) { if (CE->getCastKind() == CK_LValueToRValue) { if (CE->getSubExpr()->getType().getObjCLifetime() == Qualifiers::OCL_Weak) return CE->getSubExpr(); } } return nullptr; } RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E, ReturnValueSlot Return) { // 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. bool isDelegateInit = E->isDelegateInitCall(); const ObjCMethodDecl *method = E->getMethodDecl(); // If the method is -retain, and the receiver's being loaded from // a __weak variable, peephole the entire operation to objc_loadWeakRetained. if (method && E->getReceiverKind() == ObjCMessageExpr::Instance && method->getMethodFamily() == OMF_retain) { if (auto lvalueExpr = findWeakLValue(E->getInstanceReceiver())) { LValue lvalue = EmitLValue(lvalueExpr); llvm::Value *result = EmitARCLoadWeakRetained(lvalue.getAddress()); return AdjustObjCObjectType(*this, E->getType(), RValue::get(result)); } } // We don't retain the receiver in delegate init calls, and this is // safe because the receiver value is always loaded from 'self', // which we zero out. We don't want to Block_copy block receivers, // though. bool retainSelf = (!isDelegateInit && CGM.getLangOpts().ObjCAutoRefCount && method && method->hasAttr<NSConsumesSelfAttr>()); CGObjCRuntime &Runtime = CGM.getObjCRuntime(); bool isSuperMessage = false; bool isClassMessage = false; ObjCInterfaceDecl *OID = nullptr; // Find the receiver QualType ReceiverType; llvm::Value *Receiver = nullptr; switch (E->getReceiverKind()) { case ObjCMessageExpr::Instance: ReceiverType = E->getInstanceReceiver()->getType(); if (retainSelf) { TryEmitResult ter = tryEmitARCRetainScalarExpr(*this, E->getInstanceReceiver()); Receiver = ter.getPointer(); if (ter.getInt()) retainSelf = false; } else Receiver = EmitScalarExpr(E->getInstanceReceiver()); break; case ObjCMessageExpr::Class: { ReceiverType = E->getClassReceiver(); const ObjCObjectType *ObjTy = ReceiverType->getAs<ObjCObjectType>(); assert(ObjTy && "Invalid Objective-C class message send"); OID = ObjTy->getInterface(); assert(OID && "Invalid Objective-C class message send"); Receiver = Runtime.GetClass(*this, OID); isClassMessage = true; break; } case ObjCMessageExpr::SuperInstance: ReceiverType = E->getSuperType(); Receiver = LoadObjCSelf(); isSuperMessage = true; break; case ObjCMessageExpr::SuperClass: ReceiverType = E->getSuperType(); Receiver = LoadObjCSelf(); isSuperMessage = true; isClassMessage = true; break; } if (retainSelf) Receiver = EmitARCRetainNonBlock(Receiver); // In ARC, we sometimes want to "extend the lifetime" // (i.e. retain+autorelease) of receivers of returns-inner-pointer // messages. if (getLangOpts().ObjCAutoRefCount && method && method->hasAttr<ObjCReturnsInnerPointerAttr>() && shouldExtendReceiverForInnerPointerMessage(E)) Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver); QualType ResultType = method ? method->getReturnType() : E->getType(); CallArgList Args; EmitCallArgs(Args, method, E->arguments()); // For delegate init calls in ARC, do an unsafe store of null into // self. This represents the call taking direct ownership of that // value. We have to do this after emitting the other call // arguments because they might also reference self, but we don't // have to worry about any of them modifying self because that would // be an undefined read and write of an object in unordered // expressions. if (isDelegateInit) { assert(getLangOpts().ObjCAutoRefCount && "delegate init calls should only be marked in ARC"); // Do an unsafe store of null into self. Address selfAddr = GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()); Builder.CreateStore(getNullForVariable(selfAddr), selfAddr); } RValue result; if (isSuperMessage) { // super is only valid in an Objective-C method const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext()); result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType, E->getSelector(), OMD->getClassInterface(), isCategoryImpl, Receiver, isClassMessage, Args, method); } else { result = Runtime.GenerateMessageSend(*this, Return, ResultType, E->getSelector(), Receiver, Args, OID, method); } // For delegate init calls in ARC, implicitly store the result of // the call back into self. This takes ownership of the value. if (isDelegateInit) { Address selfAddr = GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()); llvm::Value *newSelf = result.getScalarVal(); // The delegate return type isn't necessarily a matching type; in // fact, it's quite likely to be 'id'. llvm::Type *selfTy = selfAddr.getElementType(); newSelf = Builder.CreateBitCast(newSelf, selfTy); Builder.CreateStore(newSelf, selfAddr); } return AdjustObjCObjectType(*this, E->getType(), result); } namespace { struct FinishARCDealloc final : EHScopeStack::Cleanup { void Emit(CodeGenFunction &CGF, Flags flags) override { const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl); const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext()); const ObjCInterfaceDecl *iface = impl->getClassInterface(); if (!iface->getSuperClass()) return; bool isCategory = isa<ObjCCategoryImplDecl>(impl); // Call [super dealloc] if we have a superclass. llvm::Value *self = CGF.LoadObjCSelf(); CallArgList args; CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(), CGF.getContext().VoidTy, method->getSelector(), iface, isCategory, self, /*is class msg*/ false, args, method); } }; } /// 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) { SourceLocation StartLoc = OMD->getLocStart(); FunctionArgList args; // Check if we should generate debug info for this method. if (OMD->hasAttr<NoDebugAttr>()) DebugInfo = nullptr; // disable debug info indefinitely for this function llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD); const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD); CGM.SetInternalFunctionAttributes(OMD, Fn, FI); args.push_back(OMD->getSelfDecl()); args.push_back(OMD->getCmdDecl()); args.append(OMD->param_begin(), OMD->param_end()); CurGD = OMD; CurEHLocation = OMD->getLocEnd(); StartFunction(OMD, OMD->getReturnType(), Fn, FI, args, OMD->getLocation(), StartLoc); // In ARC, certain methods get an extra cleanup. if (CGM.getLangOpts().ObjCAutoRefCount && OMD->isInstanceMethod() && OMD->getSelector().isUnarySelector()) { const IdentifierInfo *ident = OMD->getSelector().getIdentifierInfoForSlot(0); if (ident->isStr("dealloc")) EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind()); } } static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF, LValue lvalue, QualType type); /// 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()); PGO.assignRegionCounters(GlobalDecl(OMD), CurFn); assert(isa<CompoundStmt>(OMD->getBody())); incrementProfileCounter(OMD->getBody()); EmitCompoundStmtWithoutScope(*cast<CompoundStmt>(OMD->getBody())); FinishFunction(OMD->getBodyRBrace()); } /// emitStructGetterCall - Call the runtime function to load a property /// into the return value slot. static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar, bool isAtomic, bool hasStrong) { ASTContext &Context = CGF.getContext(); Address src = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0) .getAddress(); // objc_copyStruct (ReturnValue, &structIvar, // sizeof (Type of Ivar), isAtomic, false); CallArgList args; Address dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy); args.add(RValue::get(dest.getPointer()), Context.VoidPtrTy); src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy); args.add(RValue::get(src.getPointer()), Context.VoidPtrTy); CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType()); args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType()); args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy); args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy); llvm::Value *fn = CGF.CGM.getObjCRuntime().GetGetStructFunction(); CGF.EmitCall(CGF.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, args), fn, ReturnValueSlot(), args); } /// Determine whether the given architecture supports unaligned atomic /// accesses. They don't have to be fast, just faster than a function /// call and a mutex. static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) { // FIXME: Allow unaligned atomic load/store on x86. (It is not // currently supported by the backend.) return 0; } /// Return the maximum size that permits atomic accesses for the given /// architecture. static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM, llvm::Triple::ArchType arch) { // ARM has 8-byte atomic accesses, but it's not clear whether we // want to rely on them here. // In the default case, just assume that any size up to a pointer is // fine given adequate alignment. return CharUnits::fromQuantity(CGM.PointerSizeInBytes); } namespace { class PropertyImplStrategy { public: enum StrategyKind { /// The 'native' strategy is to use the architecture's provided /// reads and writes. Native, /// Use objc_setProperty and objc_getProperty. GetSetProperty, /// Use objc_setProperty for the setter, but use expression /// evaluation for the getter. SetPropertyAndExpressionGet, /// Use objc_copyStruct. CopyStruct, /// The 'expression' strategy is to emit normal assignment or /// lvalue-to-rvalue expressions. Expression }; StrategyKind getKind() const { return StrategyKind(Kind); } bool hasStrongMember() const { return HasStrong; } bool isAtomic() const { return IsAtomic; } bool isCopy() const { return IsCopy; } CharUnits getIvarSize() const { return IvarSize; } CharUnits getIvarAlignment() const { return IvarAlignment; } PropertyImplStrategy(CodeGenModule &CGM, const ObjCPropertyImplDecl *propImpl); private: unsigned Kind : 8; unsigned IsAtomic : 1; unsigned IsCopy : 1; unsigned HasStrong : 1; CharUnits IvarSize; CharUnits IvarAlignment; }; } /// Pick an implementation strategy for the given property synthesis. PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM, const ObjCPropertyImplDecl *propImpl) { const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind(); IsCopy = (setterKind == ObjCPropertyDecl::Copy); IsAtomic = prop->isAtomic(); HasStrong = false; // doesn't matter here. // Evaluate the ivar's size and alignment. ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); QualType ivarType = ivar->getType(); std::tie(IvarSize, IvarAlignment) = CGM.getContext().getTypeInfoInChars(ivarType); // If we have a copy property, we always have to use getProperty/setProperty. // TODO: we could actually use setProperty and an expression for non-atomics. if (IsCopy) { Kind = GetSetProperty; return; } // Handle retain. if (setterKind == ObjCPropertyDecl::Retain) { // In GC-only, there's nothing special that needs to be done. if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { // fallthrough // In ARC, if the property is non-atomic, use expression emission, // which translates to objc_storeStrong. This isn't required, but // it's slightly nicer. } else if (CGM.getLangOpts().ObjCAutoRefCount && !IsAtomic) { // Using standard expression emission for the setter is only // acceptable if the ivar is __strong, which won't be true if // the property is annotated with __attribute__((NSObject)). // TODO: falling all the way back to objc_setProperty here is // just laziness, though; we could still use objc_storeStrong // if we hacked it right. if (ivarType.getObjCLifetime() == Qualifiers::OCL_Strong) Kind = Expression; else Kind = SetPropertyAndExpressionGet; return; // Otherwise, we need to at least use setProperty. However, if // the property isn't atomic, we can use normal expression // emission for the getter. } else if (!IsAtomic) { Kind = SetPropertyAndExpressionGet; return; // Otherwise, we have to use both setProperty and getProperty. } else { Kind = GetSetProperty; return; } } // If we're not atomic, just use expression accesses. if (!IsAtomic) { Kind = Expression; return; } // Properties on bitfield ivars need to be emitted using expression // accesses even if they're nominally atomic. if (ivar->isBitField()) { Kind = Expression; return; } // GC-qualified or ARC-qualified ivars need to be emitted as // expressions. This actually works out to being atomic anyway, // except for ARC __strong, but that should trigger the above code. if (ivarType.hasNonTrivialObjCLifetime() || (CGM.getLangOpts().getGC() && CGM.getContext().getObjCGCAttrKind(ivarType))) { Kind = Expression; return; } // Compute whether the ivar has strong members. if (CGM.getLangOpts().getGC()) if (const RecordType *recordType = ivarType->getAs<RecordType>()) HasStrong = recordType->getDecl()->hasObjectMember(); // We can never access structs with object members with a native // access, because we need to use write barriers. This is what // objc_copyStruct is for. if (HasStrong) { Kind = CopyStruct; return; } // Otherwise, this is target-dependent and based on the size and // alignment of the ivar. // If the size of the ivar is not a power of two, give up. We don't // want to get into the business of doing compare-and-swaps. if (!IvarSize.isPowerOfTwo()) { Kind = CopyStruct; return; } llvm::Triple::ArchType arch = CGM.getTarget().getTriple().getArch(); // Most architectures require memory to fit within a single cache // line, so the alignment has to be at least the size of the access. // Otherwise we have to grab a lock. if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) { Kind = CopyStruct; return; } // If the ivar's size exceeds the architecture's maximum atomic // access size, we have to use CopyStruct. if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) { Kind = CopyStruct; return; } // Otherwise, we can use native loads and stores. Kind = Native; } /// \brief 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) { llvm::Constant *AtomicHelperFn = CodeGenFunction(CGM).GenerateObjCAtomicGetterCopyHelperFunction(PID); const ObjCPropertyDecl *PD = PID->getPropertyDecl(); ObjCMethodDecl *OMD = PD->getGetterMethodDecl(); assert(OMD && "Invalid call to generate getter (empty method)"); StartObjCMethod(OMD, IMP->getClassInterface()); generateObjCGetterBody(IMP, PID, OMD, AtomicHelperFn); FinishFunction(); } static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) { const Expr *getter = propImpl->getGetterCXXConstructor(); if (!getter) return true; // Sema only makes only of these when the ivar has a C++ class type, // so the form is pretty constrained. // If the property has a reference type, we might just be binding a // reference, in which case the result will be a gl-value. We should // treat this as a non-trivial operation. if (getter->isGLValue()) return false; // If we selected a trivial copy-constructor, we're okay. if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter)) return (construct->getConstructor()->isTrivial()); // The constructor might require cleanups (in which case it's never // trivial). assert(isa<ExprWithCleanups>(getter)); return false; } /// emitCPPObjectAtomicGetterCall - Call the runtime function to /// copy the ivar into the resturn slot. static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF, llvm::Value *returnAddr, ObjCIvarDecl *ivar, llvm::Constant *AtomicHelperFn) { // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar, // AtomicHelperFn); CallArgList args; // The 1st argument is the return Slot. args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy); // The 2nd argument is the address of the ivar. llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0).getPointer(); ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); // Third argument is the helper function. args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy); llvm::Value *copyCppAtomicObjectFn = CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction(); CGF.EmitCall( CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args), copyCppAtomicObjectFn, ReturnValueSlot(), args); } void CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl, const ObjCPropertyImplDecl *propImpl, const ObjCMethodDecl *GetterMethodDecl, llvm::Constant *AtomicHelperFn) { // If there's a non-trivial 'get' expression, we just have to emit that. if (!hasTrivialGetExpr(propImpl)) { if (!AtomicHelperFn) { ReturnStmt ret(SourceLocation(), propImpl->getGetterCXXConstructor(), /*nrvo*/ nullptr); EmitReturnStmt(ret); } else { ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); emitCPPObjectAtomicGetterCall(*this, ReturnValue.getPointer(), ivar, AtomicHelperFn); } return; } const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); QualType propType = prop->getType(); ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl(); ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); // Pick an implementation strategy. PropertyImplStrategy strategy(CGM, propImpl); switch (strategy.getKind()) { case PropertyImplStrategy::Native: { // We don't need to do anything for a zero-size struct. if (strategy.getIvarSize().isZero()) return; LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0); // Currently, all atomic accesses have to be through integer // types, so there's no point in trying to pick a prettier type. uint64_t ivarSize = getContext().toBits(strategy.getIvarSize()); llvm::Type *bitcastType = llvm::Type::getIntNTy(getLLVMContext(), ivarSize); bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay // Perform an atomic load. This does not impose ordering constraints. Address ivarAddr = LV.getAddress(); ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType); llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load"); load->setAtomic(llvm::AtomicOrdering::Unordered); // Store that value into the return address. Doing this with a // bitcast is likely to produce some pretty ugly IR, but it's not // the *most* terrible thing in the world. llvm::Type *retTy = ConvertType(getterMethod->getReturnType()); uint64_t retTySize = CGM.getDataLayout().getTypeSizeInBits(retTy); llvm::Value *ivarVal = load; if (ivarSize > retTySize) { llvm::Type *newTy = llvm::Type::getIntNTy(getLLVMContext(), retTySize); ivarVal = Builder.CreateTrunc(load, newTy); bitcastType = newTy->getPointerTo(); } Builder.CreateStore(ivarVal, Builder.CreateBitCast(ReturnValue, bitcastType)); // Make sure we don't do an autorelease. AutoreleaseResult = false; return; } case PropertyImplStrategy::GetSetProperty: { llvm::Value *getPropertyFn = CGM.getObjCRuntime().GetPropertyGetFunction(); if (!getPropertyFn) { CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy"); 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. llvm::Value *cmd = Builder.CreateLoad(GetAddrOfLocalVar(getterMethod->getCmdDecl()), "cmd"); llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy); llvm::Value *ivarOffset = EmitIvarOffset(classImpl->getClassInterface(), ivar); CallArgList args; args.add(RValue::get(self), getContext().getObjCIdType()); args.add(RValue::get(cmd), getContext().getObjCSelType()); args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); args.add(RValue::get(Builder.getInt1(strategy.isAtomic())), getContext().BoolTy); // FIXME: We shouldn't need to get the function info here, the // runtime already should have computed it to build the function. llvm::Instruction *CallInstruction; RValue RV = EmitCall( getTypes().arrangeBuiltinFunctionCall(propType, args), getPropertyFn, ReturnValueSlot(), args, CGCalleeInfo(), &CallInstruction); if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(CallInstruction)) call->setTailCall(); // 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(), getTypes().ConvertType(getterMethod->getReturnType()))); EmitReturnOfRValue(RV, propType); // objc_getProperty does an autorelease, so we should suppress ours. AutoreleaseResult = false; return; } case PropertyImplStrategy::CopyStruct: emitStructGetterCall(*this, ivar, strategy.isAtomic(), strategy.hasStrongMember()); return; case PropertyImplStrategy::Expression: case PropertyImplStrategy::SetPropertyAndExpressionGet: { LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0); QualType ivarType = ivar->getType(); switch (getEvaluationKind(ivarType)) { case TEK_Complex: { ComplexPairTy pair = EmitLoadOfComplex(LV, SourceLocation()); EmitStoreOfComplex(pair, MakeAddrLValue(ReturnValue, ivarType), /*init*/ true); return; } case TEK_Aggregate: // The return value slot is guaranteed to not be aliased, but // that's not necessarily the same as "on the stack", so // we still potentially need objc_memmove_collectable. EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType); return; case TEK_Scalar: { llvm::Value *value; if (propType->isReferenceType()) { value = LV.getAddress().getPointer(); } else { // We want to load and autoreleaseReturnValue ARC __weak ivars. if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) { if (getLangOpts().ObjCAutoRefCount) { value = emitARCRetainLoadOfScalar(*this, LV, ivarType); } else { value = EmitARCLoadWeak(LV.getAddress()); } // Otherwise we want to do a simple load, suppressing the // final autorelease. } else { value = EmitLoadOfLValue(LV, SourceLocation()).getScalarVal(); AutoreleaseResult = false; } value = Builder.CreateBitCast( value, ConvertType(GetterMethodDecl->getReturnType())); } EmitReturnOfRValue(RValue::get(value), propType); return; } } llvm_unreachable("bad evaluation kind"); } } llvm_unreachable("bad @property implementation strategy!"); } /// emitStructSetterCall - Call the runtime function to store the value /// from the first formal parameter into the given ivar. static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD, ObjCIvarDecl *ivar) { // objc_copyStruct (&structIvar, &Arg, // sizeof (struct something), true, false); CallArgList args; // The first argument is the address of the ivar. llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0) .getPointer(); ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); // The second argument is the address of the parameter variable. ParmVarDecl *argVar = *OMD->param_begin(); DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), VK_LValue, SourceLocation()); llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(); argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy); args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy); // The third argument is the sizeof the type. llvm::Value *size = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType())); args.add(RValue::get(size), CGF.getContext().getSizeType()); // The fourth argument is the 'isAtomic' flag. args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy); // The fifth argument is the 'hasStrong' flag. // FIXME: should this really always be false? args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy); llvm::Value *copyStructFn = CGF.CGM.getObjCRuntime().GetSetStructFunction(); CGF.EmitCall( CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args), copyStructFn, ReturnValueSlot(), args); } /// emitCPPObjectAtomicSetterCall - Call the runtime function to store /// the value from the first formal parameter into the given ivar, using /// the Cpp API for atomic Cpp objects with non-trivial copy assignment. static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD, ObjCIvarDecl *ivar, llvm::Constant *AtomicHelperFn) { // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg, // AtomicHelperFn); CallArgList args; // The first argument is the address of the ivar. llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0).getPointer(); ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); // The second argument is the address of the parameter variable. ParmVarDecl *argVar = *OMD->param_begin(); DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), VK_LValue, SourceLocation()); llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(); argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy); args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy); // Third argument is the helper function. args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy); llvm::Value *copyCppAtomicObjectFn = CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction(); CGF.EmitCall( CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args), copyCppAtomicObjectFn, ReturnValueSlot(), args); } static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) { Expr *setter = PID->getSetterCXXAssignment(); if (!setter) return true; // Sema only makes only of these when the ivar has a C++ class type, // so the form is pretty constrained. // An operator call is trivial if the function it calls is trivial. // This also implies that there's nothing non-trivial going on with // the arguments, because operator= can only be trivial if it's a // synthesized assignment operator and therefore both parameters are // references. if (CallExpr *call = dyn_cast<CallExpr>(setter)) { if (const FunctionDecl *callee = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl())) if (callee->isTrivial()) return true; return false; } assert(isa<ExprWithCleanups>(setter)); return false; } static bool UseOptimizedSetter(CodeGenModule &CGM) { if (CGM.getLangOpts().getGC() != LangOptions::NonGC) return false; return CGM.getLangOpts().ObjCRuntime.hasOptimizedSetter(); } void CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl, const ObjCPropertyImplDecl *propImpl, llvm::Constant *AtomicHelperFn) { const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl(); // Just use the setter expression if Sema gave us one and it's // non-trivial. if (!hasTrivialSetExpr(propImpl)) { if (!AtomicHelperFn) // If non-atomic, assignment is called directly. EmitStmt(propImpl->getSetterCXXAssignment()); else // If atomic, assignment is called via a locking api. emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar, AtomicHelperFn); return; } PropertyImplStrategy strategy(CGM, propImpl); switch (strategy.getKind()) { case PropertyImplStrategy::Native: { // We don't need to do anything for a zero-size struct. if (strategy.getIvarSize().isZero()) return; Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin()); LValue ivarLValue = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0); Address ivarAddr = ivarLValue.getAddress(); // Currently, all atomic accesses have to be through integer // types, so there's no point in trying to pick a prettier type. llvm::Type *bitcastType = llvm::Type::getIntNTy(getLLVMContext(), getContext().toBits(strategy.getIvarSize())); // Cast both arguments to the chosen operation type. argAddr = Builder.CreateElementBitCast(argAddr, bitcastType); ivarAddr = Builder.CreateElementBitCast(ivarAddr, bitcastType); // This bitcast load is likely to cause some nasty IR. llvm::Value *load = Builder.CreateLoad(argAddr); // Perform an atomic store. There are no memory ordering requirements. llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr); store->setAtomic(llvm::AtomicOrdering::Unordered); return; } case PropertyImplStrategy::GetSetProperty: case PropertyImplStrategy::SetPropertyAndExpressionGet: { llvm::Value *setOptimizedPropertyFn = nullptr; llvm::Value *setPropertyFn = nullptr; if (UseOptimizedSetter(CGM)) { // 10.8 and iOS 6.0 code and GC is off setOptimizedPropertyFn = CGM.getObjCRuntime() .GetOptimizedPropertySetFunction(strategy.isAtomic(), strategy.isCopy()); if (!setOptimizedPropertyFn) { CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI"); return; } } else { setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction(); if (!setPropertyFn) { CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy"); return; } } // Emit objc_setProperty((id) self, _cmd, offset, arg, // <is-atomic>, <is-copy>). llvm::Value *cmd = Builder.CreateLoad(GetAddrOfLocalVar(setterMethod->getCmdDecl())); llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy); llvm::Value *ivarOffset = EmitIvarOffset(classImpl->getClassInterface(), ivar); Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin()); llvm::Value *arg = Builder.CreateLoad(argAddr, "arg"); arg = Builder.CreateBitCast(arg, VoidPtrTy); CallArgList args; args.add(RValue::get(self), getContext().getObjCIdType()); args.add(RValue::get(cmd), getContext().getObjCSelType()); if (setOptimizedPropertyFn) { args.add(RValue::get(arg), getContext().getObjCIdType()); args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args), setOptimizedPropertyFn, ReturnValueSlot(), args); } else { args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); args.add(RValue::get(arg), getContext().getObjCIdType()); args.add(RValue::get(Builder.getInt1(strategy.isAtomic())), getContext().BoolTy); args.add(RValue::get(Builder.getInt1(strategy.isCopy())), getContext().BoolTy); // FIXME: We shouldn't need to get the function info here, the runtime // already should have computed it to build the function. EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args), setPropertyFn, ReturnValueSlot(), args); } return; } case PropertyImplStrategy::CopyStruct: emitStructSetterCall(*this, setterMethod, ivar); return; case PropertyImplStrategy::Expression: break; } // Otherwise, fake up some ASTs and emit a normal assignment. ValueDecl *selfDecl = setterMethod->getSelfDecl(); DeclRefExpr self(selfDecl, false, selfDecl->getType(), VK_LValue, SourceLocation()); ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack, selfDecl->getType(), CK_LValueToRValue, &self, VK_RValue); ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(), SourceLocation(), SourceLocation(), &selfLoad, true, true); ParmVarDecl *argDecl = *setterMethod->param_begin(); QualType argType = argDecl->getType().getNonReferenceType(); DeclRefExpr arg(argDecl, false, argType, VK_LValue, SourceLocation()); ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack, argType.getUnqualifiedType(), CK_LValueToRValue, &arg, VK_RValue); // The property type can differ from the ivar type in some situations with // Objective-C pointer types, we can always bit cast the RHS in these cases. // The following absurdity is just to ensure well-formed IR. CastKind argCK = CK_NoOp; if (ivarRef.getType()->isObjCObjectPointerType()) { if (argLoad.getType()->isObjCObjectPointerType()) argCK = CK_BitCast; else if (argLoad.getType()->isBlockPointerType()) argCK = CK_BlockPointerToObjCPointerCast; else argCK = CK_CPointerToObjCPointerCast; } else if (ivarRef.getType()->isBlockPointerType()) { if (argLoad.getType()->isBlockPointerType()) argCK = CK_BitCast; else argCK = CK_AnyPointerToBlockPointerCast; } else if (ivarRef.getType()->isPointerType()) { argCK = CK_BitCast; } ImplicitCastExpr argCast(ImplicitCastExpr::OnStack, ivarRef.getType(), argCK, &argLoad, VK_RValue); Expr *finalArg = &argLoad; if (!getContext().hasSameUnqualifiedType(ivarRef.getType(), argLoad.getType())) finalArg = &argCast; BinaryOperator assign(&ivarRef, finalArg, BO_Assign, ivarRef.getType(), VK_RValue, OK_Ordinary, SourceLocation(), false); EmitStmt(&assign); } /// \brief 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) { llvm::Constant *AtomicHelperFn = CodeGenFunction(CGM).GenerateObjCAtomicSetterCopyHelperFunction(PID); const ObjCPropertyDecl *PD = PID->getPropertyDecl(); ObjCMethodDecl *OMD = PD->getSetterMethodDecl(); assert(OMD && "Invalid call to generate setter (empty method)"); StartObjCMethod(OMD, IMP->getClassInterface()); generateObjCSetterBody(IMP, PID, AtomicHelperFn); FinishFunction(); } namespace { struct DestroyIvar final : EHScopeStack::Cleanup { private: llvm::Value *addr; const ObjCIvarDecl *ivar; CodeGenFunction::Destroyer *destroyer; bool useEHCleanupForArray; public: DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar, CodeGenFunction::Destroyer *destroyer, bool useEHCleanupForArray) : addr(addr), ivar(ivar), destroyer(destroyer), useEHCleanupForArray(useEHCleanupForArray) {} void Emit(CodeGenFunction &CGF, Flags flags) override { LValue lvalue = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0); CGF.emitDestroy(lvalue.getAddress(), ivar->getType(), destroyer, flags.isForNormalCleanup() && useEHCleanupForArray); } }; } /// Like CodeGenFunction::destroyARCStrong, but do it with a call. static void destroyARCStrongWithStore(CodeGenFunction &CGF, Address addr, QualType type) { llvm::Value *null = getNullForVariable(addr); CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true); } static void emitCXXDestructMethod(CodeGenFunction &CGF, ObjCImplementationDecl *impl) { CodeGenFunction::RunCleanupsScope scope(CGF); llvm::Value *self = CGF.LoadObjCSelf(); const ObjCInterfaceDecl *iface = impl->getClassInterface(); for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); ivar; ivar = ivar->getNextIvar()) { QualType type = ivar->getType(); // Check whether the ivar is a destructible type. QualType::DestructionKind dtorKind = type.isDestructedType(); if (!dtorKind) continue; CodeGenFunction::Destroyer *destroyer = nullptr; // Use a call to objc_storeStrong to destroy strong ivars, for the // general benefit of the tools. if (dtorKind == QualType::DK_objc_strong_lifetime) { destroyer = destroyARCStrongWithStore; // Otherwise use the default for the destruction kind. } else { destroyer = CGF.getDestroyer(dtorKind); } CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind); CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer, cleanupKind & EHCleanup); } assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?"); } void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP, ObjCMethodDecl *MD, bool ctor) { MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface()); StartObjCMethod(MD, IMP->getClassInterface()); // Emit .cxx_construct. if (ctor) { // Suppress the final autorelease in ARC. AutoreleaseResult = false; for (const auto *IvarInit : IMP->inits()) { FieldDecl *Field = IvarInit->getAnyMember(); ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field); LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), Ivar, 0); EmitAggExpr(IvarInit->getInit(), AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased)); } // constructor returns 'self'. CodeGenTypes &Types = CGM.getTypes(); QualType IdTy(CGM.getContext().getObjCIdType()); llvm::Value *SelfAsId = Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy)); EmitReturnOfRValue(RValue::get(SelfAsId), IdTy); // Emit .cxx_destruct. } else { emitCXXDestructMethod(*this, IMP); } FinishFunction(); } llvm::Value *CodeGenFunction::LoadObjCSelf() { VarDecl *Self = cast<ObjCMethodDecl>(CurFuncDecl)->getSelfDecl(); DeclRefExpr DRE(Self, /*is enclosing local*/ (CurFuncDecl != CurCodeDecl), Self->getType(), VK_LValue, SourceLocation()); return EmitLoadOfScalar(EmitDeclRefLValue(&DRE), SourceLocation()); } QualType CodeGenFunction::TypeOfSelfObject() { const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); ImplicitParamDecl *selfDecl = OMD->getSelfDecl(); const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>( getContext().getCanonicalType(selfDecl->getType())); return PTy->getPointeeType(); } void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){ llvm::Constant *EnumerationMutationFn = CGM.getObjCRuntime().EnumerationMutationFunction(); if (!EnumerationMutationFn) { CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime"); return; } CGDebugInfo *DI = getDebugInfo(); if (DI) DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin()); // The local variable comes into scope immediately. AutoVarEmission variable = AutoVarEmission::invalid(); if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl())); JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end"); // Fast enumeration state. QualType StateTy = CGM.getObjCFastEnumerationStateType(); Address StatePtr = CreateMemTemp(StateTy, "state.ptr"); EmitNullInitialization(StatePtr, StateTy); // Number of elements in the items array. static const unsigned NumItems = 16; // Fetch the countByEnumeratingWithState:objects:count: selector. IdentifierInfo *II[] = { &CGM.getContext().Idents.get("countByEnumeratingWithState"), &CGM.getContext().Idents.get("objects"), &CGM.getContext().Idents.get("count") }; Selector FastEnumSel = CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]); QualType ItemsTy = getContext().getConstantArrayType(getContext().getObjCIdType(), llvm::APInt(32, NumItems), ArrayType::Normal, 0); Address ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr"); RunCleanupsScope ForScope(*this); // Emit the collection pointer. In ARC, we do a retain. llvm::Value *Collection; if (getLangOpts().ObjCAutoRefCount) { Collection = EmitARCRetainScalarExpr(S.getCollection()); // Enter a cleanup to do the release. EmitObjCConsumeObject(S.getCollection()->getType(), Collection); } else { Collection = EmitScalarExpr(S.getCollection()); } // The 'continue' label needs to appear within the cleanup for the // collection object. JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next"); // Send it our message: CallArgList Args; // The first argument is a temporary of the enumeration-state type. Args.add(RValue::get(StatePtr.getPointer()), getContext().getPointerType(StateTy)); // The second argument is a temporary array with space for NumItems // pointers. We'll actually be loading elements from the array // pointer written into the control state; this buffer is so that // collections that *aren't* backed by arrays can still queue up // batches of elements. Args.add(RValue::get(ItemsPtr.getPointer()), getContext().getPointerType(ItemsTy)); // The third argument is the capacity of that temporary array. llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy); llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems); Args.add(RValue::get(Count), getContext().UnsignedLongTy); // Start the enumeration. RValue CountRV = CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), getContext().UnsignedLongTy, FastEnumSel, Collection, Args); // The initial number of objects that were returned in the buffer. llvm::Value *initialBufferLimit = CountRV.getScalarVal(); llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty"); llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit"); llvm::Value *zero = llvm::Constant::getNullValue(UnsignedLongLTy); // If the limit pointer was zero to begin with, the collection is // empty; skip all this. Set the branch weight assuming this has the same // probability of exiting the loop as any other loop exit. uint64_t EntryCount = getCurrentProfileCount(); Builder.CreateCondBr( Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), EmptyBB, LoopInitBB, createProfileWeights(EntryCount, getProfileCount(S.getBody()))); // Otherwise, initialize the loop. EmitBlock(LoopInitBB); // Save the initial mutations value. This is the value at an // address that was written into the state object by // countByEnumeratingWithState:objects:count:. Address StateMutationsPtrPtr = Builder.CreateStructGEP( StatePtr, 2, 2 * getPointerSize(), "mutationsptr.ptr"); llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr"); llvm::Value *initialMutations = Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(), "forcoll.initial-mutations"); // Start looping. This is the point we return to whenever we have a // fresh, non-empty batch of objects. llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody"); EmitBlock(LoopBodyBB); // The current index into the buffer. llvm::PHINode *index = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.index"); index->addIncoming(zero, LoopInitBB); // The current buffer size. llvm::PHINode *count = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.count"); count->addIncoming(initialBufferLimit, LoopInitBB); incrementProfileCounter(&S); // Check whether the mutations value has changed from where it was // at start. StateMutationsPtr should actually be invariant between // refreshes. StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr"); llvm::Value *currentMutations = Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(), "statemutations"); llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated"); llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated"); Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations), WasNotMutatedBB, WasMutatedBB); // If so, call the enumeration-mutation function. EmitBlock(WasMutatedBB); llvm::Value *V = Builder.CreateBitCast(Collection, ConvertType(getContext().getObjCIdType())); CallArgList Args2; Args2.add(RValue::get(V), getContext().getObjCIdType()); // FIXME: We shouldn't need to get the function info here, the runtime already // should have computed it to build the function. EmitCall( CGM.getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, Args2), EnumerationMutationFn, ReturnValueSlot(), Args2); // Otherwise, or if the mutation function returns, just continue. EmitBlock(WasNotMutatedBB); // Initialize the element variable. RunCleanupsScope elementVariableScope(*this); bool elementIsVariable; LValue elementLValue; QualType elementType; if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) { // Initialize the variable, in case it's a __block variable or something. EmitAutoVarInit(variable); const VarDecl* D = cast<VarDecl>(SD->getSingleDecl()); DeclRefExpr tempDRE(const_cast<VarDecl*>(D), false, D->getType(), VK_LValue, SourceLocation()); elementLValue = EmitLValue(&tempDRE); elementType = D->getType(); elementIsVariable = true; if (D->isARCPseudoStrong()) elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone); } else { elementLValue = LValue(); // suppress warning elementType = cast<Expr>(S.getElement())->getType(); elementIsVariable = false; } llvm::Type *convertedElementType = ConvertType(elementType); // Fetch the buffer out of the enumeration state. // TODO: this pointer should actually be invariant between // refreshes, which would help us do certain loop optimizations. Address StateItemsPtr = Builder.CreateStructGEP( StatePtr, 1, getPointerSize(), "stateitems.ptr"); llvm::Value *EnumStateItems = Builder.CreateLoad(StateItemsPtr, "stateitems"); // Fetch the value at the current index from the buffer. llvm::Value *CurrentItemPtr = Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr"); llvm::Value *CurrentItem = Builder.CreateAlignedLoad(CurrentItemPtr, getPointerAlign()); // Cast that value to the right type. CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType, "currentitem"); // Make sure we have an l-value. Yes, this gets evaluated every // time through the loop. if (!elementIsVariable) { elementLValue = EmitLValue(cast<Expr>(S.getElement())); EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue); } else { EmitScalarInit(CurrentItem, elementLValue); } // If we do have an element variable, this assignment is the end of // its initialization. if (elementIsVariable) EmitAutoVarCleanups(variable); // Perform the loop body, setting up break and continue labels. BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody)); { RunCleanupsScope Scope(*this); EmitStmt(S.getBody()); } BreakContinueStack.pop_back(); // Destroy the element variable now. elementVariableScope.ForceCleanup(); // Check whether there are more elements. EmitBlock(AfterBody.getBlock()); llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch"); // First we check in the local buffer. llvm::Value *indexPlusOne = Builder.CreateAdd(index, llvm::ConstantInt::get(UnsignedLongLTy, 1)); // If we haven't overrun the buffer yet, we can continue. // Set the branch weights based on the simplifying assumption that this is // like a while-loop, i.e., ignoring that the false branch fetches more // elements and then returns to the loop. Builder.CreateCondBr( Builder.CreateICmpULT(indexPlusOne, count), LoopBodyBB, FetchMoreBB, createProfileWeights(getProfileCount(S.getBody()), EntryCount)); index->addIncoming(indexPlusOne, AfterBody.getBlock()); count->addIncoming(count, AfterBody.getBlock()); // Otherwise, we have to fetch more elements. EmitBlock(FetchMoreBB); CountRV = CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), getContext().UnsignedLongTy, FastEnumSel, Collection, Args); // If we got a zero count, we're done. llvm::Value *refetchCount = CountRV.getScalarVal(); // (note that the message send might split FetchMoreBB) index->addIncoming(zero, Builder.GetInsertBlock()); count->addIncoming(refetchCount, Builder.GetInsertBlock()); Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero), EmptyBB, LoopBodyBB); // No more elements. EmitBlock(EmptyBB); if (!elementIsVariable) { // If the element was not a declaration, set it to be null. llvm::Value *null = llvm::Constant::getNullValue(convertedElementType); elementLValue = EmitLValue(cast<Expr>(S.getElement())); EmitStoreThroughLValue(RValue::get(null), elementLValue); } if (DI) DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd()); ForScope.ForceCleanup(); EmitBlock(LoopEnd.getBlock()); } void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) { CGM.getObjCRuntime().EmitTryStmt(*this, S); } void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) { CGM.getObjCRuntime().EmitThrowStmt(*this, S); } void CodeGenFunction::EmitObjCAtSynchronizedStmt( const ObjCAtSynchronizedStmt &S) { CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S); } namespace { struct CallObjCRelease final : EHScopeStack::Cleanup { CallObjCRelease(llvm::Value *object) : object(object) {} llvm::Value *object; void Emit(CodeGenFunction &CGF, Flags flags) override { // Releases at the end of the full-expression are imprecise. CGF.EmitARCRelease(object, ARCImpreciseLifetime); } }; } /// Produce the code for a CK_ARCConsumeObject. Does a primitive /// release at the end of the full-expression. llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type, llvm::Value *object) { // If we're in a conditional branch, we need to make the cleanup // conditional. pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object); return object; } llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type, llvm::Value *value) { return EmitARCRetainAutorelease(type, value); } /// Given a number of pointers, inform the optimizer that they're /// being intrinsically used up until this point in the program. void CodeGenFunction::EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values) { llvm::Constant *&fn = CGM.getObjCEntrypoints().clang_arc_use; if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(CGM.VoidTy, None, true); fn = CGM.CreateRuntimeFunction(fnType, "clang.arc.use"); } // This isn't really a "runtime" function, but as an intrinsic it // doesn't really matter as long as we align things up. EmitNounwindRuntimeCall(fn, values); } static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM, llvm::FunctionType *type, StringRef fnName) { llvm::Constant *fn = CGM.CreateRuntimeFunction(type, fnName); if (llvm::Function *f = dyn_cast<llvm::Function>(fn)) { // If the target runtime doesn't naturally support ARC, emit weak // references to the runtime support library. We don't really // permit this to fail, but we need a particular relocation style. if (!CGM.getLangOpts().ObjCRuntime.hasNativeARC()) { f->setLinkage(llvm::Function::ExternalWeakLinkage); } else if (fnName == "objc_retain" || fnName == "objc_release") { // If we have Native ARC, set nonlazybind attribute for these APIs for // performance. f->addFnAttr(llvm::Attribute::NonLazyBind); } } return fn; } /// Perform an operation having the signature /// i8* (i8*) /// where a null input causes a no-op and returns null. static llvm::Value *emitARCValueOperation(CodeGenFunction &CGF, llvm::Value *value, llvm::Constant *&fn, StringRef fnName, bool isTailCall = false) { if (isa<llvm::ConstantPointerNull>(value)) return value; if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrTy, false); fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); } // Cast the argument to 'id'. llvm::Type *origType = value->getType(); value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy); // Call the function. llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value); if (isTailCall) call->setTailCall(); // Cast the result back to the original type. return CGF.Builder.CreateBitCast(call, origType); } /// Perform an operation having the following signature: /// i8* (i8**) static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF, Address addr, llvm::Constant *&fn, StringRef fnName) { if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrPtrTy, false); fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); } // Cast the argument to 'id*'. llvm::Type *origType = addr.getElementType(); addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy); // Call the function. llvm::Value *result = CGF.EmitNounwindRuntimeCall(fn, addr.getPointer()); // Cast the result back to a dereference of the original type. if (origType != CGF.Int8PtrTy) result = CGF.Builder.CreateBitCast(result, origType); return result; } /// Perform an operation having the following signature: /// i8* (i8**, i8*) static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF, Address addr, llvm::Value *value, llvm::Constant *&fn, StringRef fnName, bool ignored) { assert(addr.getElementType() == value->getType()); if (!fn) { llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrTy }; llvm::FunctionType *fnType = llvm::FunctionType::get(CGF.Int8PtrTy, argTypes, false); fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); } llvm::Type *origType = value->getType(); llvm::Value *args[] = { CGF.Builder.CreateBitCast(addr.getPointer(), CGF.Int8PtrPtrTy), CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy) }; llvm::CallInst *result = CGF.EmitNounwindRuntimeCall(fn, args); if (ignored) return nullptr; return CGF.Builder.CreateBitCast(result, origType); } /// Perform an operation having the following signature: /// void (i8**, i8**) static void emitARCCopyOperation(CodeGenFunction &CGF, Address dst, Address src, llvm::Constant *&fn, StringRef fnName) { assert(dst.getType() == src.getType()); if (!fn) { llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrPtrTy }; llvm::FunctionType *fnType = llvm::FunctionType::get(CGF.Builder.getVoidTy(), argTypes, false); fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); } llvm::Value *args[] = { CGF.Builder.CreateBitCast(dst.getPointer(), CGF.Int8PtrPtrTy), CGF.Builder.CreateBitCast(src.getPointer(), CGF.Int8PtrPtrTy) }; CGF.EmitNounwindRuntimeCall(fn, args); } /// Produce the code to do a retain. Based on the type, calls one of: /// call i8* \@objc_retain(i8* %value) /// call i8* \@objc_retainBlock(i8* %value) llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) { if (type->isBlockPointerType()) return EmitARCRetainBlock(value, /*mandatory*/ false); else return EmitARCRetainNonBlock(value); } /// Retain the given object, with normal retain semantics. /// call i8* \@objc_retain(i8* %value) llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) { return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_retain, "objc_retain"); } /// Retain the given block, with _Block_copy semantics. /// call i8* \@objc_retainBlock(i8* %value) /// /// \param mandatory - If false, emit the call with metadata /// indicating that it's okay for the optimizer to eliminate this call /// if it can prove that the block never escapes except down the stack. llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value, bool mandatory) { llvm::Value *result = emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_retainBlock, "objc_retainBlock"); // If the copy isn't mandatory, add !clang.arc.copy_on_escape to // tell the optimizer that it doesn't need to do this copy if the // block doesn't escape, where being passed as an argument doesn't // count as escaping. if (!mandatory && isa<llvm::Instruction>(result)) { llvm::CallInst *call = cast<llvm::CallInst>(result->stripPointerCasts()); assert(call->getCalledValue() == CGM.getObjCEntrypoints().objc_retainBlock); call->setMetadata("clang.arc.copy_on_escape", llvm::MDNode::get(Builder.getContext(), None)); } return result; } static void emitAutoreleasedReturnValueMarker(CodeGenFunction &CGF) { // Fetch the void(void) inline asm which marks that we're going to // do something with the autoreleased return value. llvm::InlineAsm *&marker = CGF.CGM.getObjCEntrypoints().retainAutoreleasedReturnValueMarker; if (!marker) { StringRef assembly = CGF.CGM.getTargetCodeGenInfo() .getARCRetainAutoreleasedReturnValueMarker(); // If we have an empty assembly string, there's nothing to do. if (assembly.empty()) { // Otherwise, at -O0, build an inline asm that we're going to call // in a moment. } else if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) { llvm::FunctionType *type = llvm::FunctionType::get(CGF.VoidTy, /*variadic*/false); marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true); // If we're at -O1 and above, we don't want to litter the code // with this marker yet, so leave a breadcrumb for the ARC // optimizer to pick up. } else { llvm::NamedMDNode *metadata = CGF.CGM.getModule().getOrInsertNamedMetadata( "clang.arc.retainAutoreleasedReturnValueMarker"); assert(metadata->getNumOperands() <= 1); if (metadata->getNumOperands() == 0) { auto &ctx = CGF.getLLVMContext(); metadata->addOperand(llvm::MDNode::get(ctx, llvm::MDString::get(ctx, assembly))); } } } // Call the marker asm if we made one, which we do only at -O0. if (marker) CGF.Builder.CreateCall(marker); } /// Retain the given object which is the result of a function call. /// call i8* \@objc_retainAutoreleasedReturnValue(i8* %value) /// /// Yes, this function name is one character away from a different /// call with completely different semantics. llvm::Value * CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) { emitAutoreleasedReturnValueMarker(*this); return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_retainAutoreleasedReturnValue, "objc_retainAutoreleasedReturnValue"); } /// Claim a possibly-autoreleased return value at +0. This is only /// valid to do in contexts which do not rely on the retain to keep /// the object valid for for all of its uses; for example, when /// the value is ignored, or when it is being assigned to an /// __unsafe_unretained variable. /// /// call i8* \@objc_unsafeClaimAutoreleasedReturnValue(i8* %value) llvm::Value * CodeGenFunction::EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value) { emitAutoreleasedReturnValueMarker(*this); return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_unsafeClaimAutoreleasedReturnValue, "objc_unsafeClaimAutoreleasedReturnValue"); } /// Release the given object. /// call void \@objc_release(i8* %value) void CodeGenFunction::EmitARCRelease(llvm::Value *value, ARCPreciseLifetime_t precise) { if (isa<llvm::ConstantPointerNull>(value)) return; llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_release; if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false); fn = createARCRuntimeFunction(CGM, fnType, "objc_release"); } // Cast the argument to 'id'. value = Builder.CreateBitCast(value, Int8PtrTy); // Call objc_release. llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value); if (precise == ARCImpreciseLifetime) { call->setMetadata("clang.imprecise_release", llvm::MDNode::get(Builder.getContext(), None)); } } /// Destroy a __strong variable. /// /// At -O0, emit a call to store 'null' into the address; /// instrumenting tools prefer this because the address is exposed, /// but it's relatively cumbersome to optimize. /// /// At -O1 and above, just load and call objc_release. /// /// call void \@objc_storeStrong(i8** %addr, i8* null) void CodeGenFunction::EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise) { if (CGM.getCodeGenOpts().OptimizationLevel == 0) { llvm::Value *null = getNullForVariable(addr); EmitARCStoreStrongCall(addr, null, /*ignored*/ true); return; } llvm::Value *value = Builder.CreateLoad(addr); EmitARCRelease(value, precise); } /// Store into a strong object. Always calls this: /// call void \@objc_storeStrong(i8** %addr, i8* %value) llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(Address addr, llvm::Value *value, bool ignored) { assert(addr.getElementType() == value->getType()); llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_storeStrong; if (!fn) { llvm::Type *argTypes[] = { Int8PtrPtrTy, Int8PtrTy }; llvm::FunctionType *fnType = llvm::FunctionType::get(Builder.getVoidTy(), argTypes, false); fn = createARCRuntimeFunction(CGM, fnType, "objc_storeStrong"); } llvm::Value *args[] = { Builder.CreateBitCast(addr.getPointer(), Int8PtrPtrTy), Builder.CreateBitCast(value, Int8PtrTy) }; EmitNounwindRuntimeCall(fn, args); if (ignored) return nullptr; return value; } /// Store into a strong object. Sometimes calls this: /// call void \@objc_storeStrong(i8** %addr, i8* %value) /// Other times, breaks it down into components. llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst, llvm::Value *newValue, bool ignored) { QualType type = dst.getType(); bool isBlock = type->isBlockPointerType(); // Use a store barrier at -O0 unless this is a block type or the // lvalue is inadequately aligned. if (shouldUseFusedARCCalls() && !isBlock && (dst.getAlignment().isZero() || dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) { return EmitARCStoreStrongCall(dst.getAddress(), newValue, ignored); } // Otherwise, split it out. // Retain the new value. newValue = EmitARCRetain(type, newValue); // Read the old value. llvm::Value *oldValue = EmitLoadOfScalar(dst, SourceLocation()); // Store. We do this before the release so that any deallocs won't // see the old value. EmitStoreOfScalar(newValue, dst); // Finally, release the old value. EmitARCRelease(oldValue, dst.isARCPreciseLifetime()); return newValue; } /// Autorelease the given object. /// call i8* \@objc_autorelease(i8* %value) llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) { return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_autorelease, "objc_autorelease"); } /// Autorelease the given object. /// call i8* \@objc_autoreleaseReturnValue(i8* %value) llvm::Value * CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) { return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_autoreleaseReturnValue, "objc_autoreleaseReturnValue", /*isTailCall*/ true); } /// Do a fused retain/autorelease of the given object. /// call i8* \@objc_retainAutoreleaseReturnValue(i8* %value) llvm::Value * CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) { return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_retainAutoreleaseReturnValue, "objc_retainAutoreleaseReturnValue", /*isTailCall*/ true); } /// Do a fused retain/autorelease of the given object. /// call i8* \@objc_retainAutorelease(i8* %value) /// or /// %retain = call i8* \@objc_retainBlock(i8* %value) /// call i8* \@objc_autorelease(i8* %retain) llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type, llvm::Value *value) { if (!type->isBlockPointerType()) return EmitARCRetainAutoreleaseNonBlock(value); if (isa<llvm::ConstantPointerNull>(value)) return value; llvm::Type *origType = value->getType(); value = Builder.CreateBitCast(value, Int8PtrTy); value = EmitARCRetainBlock(value, /*mandatory*/ true); value = EmitARCAutorelease(value); return Builder.CreateBitCast(value, origType); } /// Do a fused retain/autorelease of the given object. /// call i8* \@objc_retainAutorelease(i8* %value) llvm::Value * CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) { return emitARCValueOperation(*this, value, CGM.getObjCEntrypoints().objc_retainAutorelease, "objc_retainAutorelease"); } /// i8* \@objc_loadWeak(i8** %addr) /// Essentially objc_autorelease(objc_loadWeakRetained(addr)). llvm::Value *CodeGenFunction::EmitARCLoadWeak(Address addr) { return emitARCLoadOperation(*this, addr, CGM.getObjCEntrypoints().objc_loadWeak, "objc_loadWeak"); } /// i8* \@objc_loadWeakRetained(i8** %addr) llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(Address addr) { return emitARCLoadOperation(*this, addr, CGM.getObjCEntrypoints().objc_loadWeakRetained, "objc_loadWeakRetained"); } /// i8* \@objc_storeWeak(i8** %addr, i8* %value) /// Returns %value. llvm::Value *CodeGenFunction::EmitARCStoreWeak(Address addr, llvm::Value *value, bool ignored) { return emitARCStoreOperation(*this, addr, value, CGM.getObjCEntrypoints().objc_storeWeak, "objc_storeWeak", ignored); } /// i8* \@objc_initWeak(i8** %addr, i8* %value) /// Returns %value. %addr is known to not have a current weak entry. /// Essentially equivalent to: /// *addr = nil; objc_storeWeak(addr, value); void CodeGenFunction::EmitARCInitWeak(Address addr, llvm::Value *value) { // If we're initializing to null, just write null to memory; no need // to get the runtime involved. But don't do this if optimization // is enabled, because accounting for this would make the optimizer // much more complicated. if (isa<llvm::ConstantPointerNull>(value) && CGM.getCodeGenOpts().OptimizationLevel == 0) { Builder.CreateStore(value, addr); return; } emitARCStoreOperation(*this, addr, value, CGM.getObjCEntrypoints().objc_initWeak, "objc_initWeak", /*ignored*/ true); } /// void \@objc_destroyWeak(i8** %addr) /// Essentially objc_storeWeak(addr, nil). void CodeGenFunction::EmitARCDestroyWeak(Address addr) { llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_destroyWeak; if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrPtrTy, false); fn = createARCRuntimeFunction(CGM, fnType, "objc_destroyWeak"); } // Cast the argument to 'id*'. addr = Builder.CreateBitCast(addr, Int8PtrPtrTy); EmitNounwindRuntimeCall(fn, addr.getPointer()); } /// void \@objc_moveWeak(i8** %dest, i8** %src) /// Disregards the current value in %dest. Leaves %src pointing to nothing. /// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)). void CodeGenFunction::EmitARCMoveWeak(Address dst, Address src) { emitARCCopyOperation(*this, dst, src, CGM.getObjCEntrypoints().objc_moveWeak, "objc_moveWeak"); } /// void \@objc_copyWeak(i8** %dest, i8** %src) /// Disregards the current value in %dest. Essentially /// objc_release(objc_initWeak(dest, objc_readWeakRetained(src))) void CodeGenFunction::EmitARCCopyWeak(Address dst, Address src) { emitARCCopyOperation(*this, dst, src, CGM.getObjCEntrypoints().objc_copyWeak, "objc_copyWeak"); } /// Produce the code to do a objc_autoreleasepool_push. /// call i8* \@objc_autoreleasePoolPush(void) llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() { llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPush; if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(Int8PtrTy, false); fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPush"); } return EmitNounwindRuntimeCall(fn); } /// Produce the code to do a primitive release. /// call void \@objc_autoreleasePoolPop(i8* %ptr) void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) { assert(value->getType() == Int8PtrTy); llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPop; if (!fn) { llvm::FunctionType *fnType = llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false); // We don't want to use a weak import here; instead we should not // fall into this path. fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPop"); } // objc_autoreleasePoolPop can throw. EmitRuntimeCallOrInvoke(fn, value); } /// Produce the code to do an MRR version objc_autoreleasepool_push. /// Which is: [[NSAutoreleasePool alloc] init]; /// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class. /// init is declared as: - (id) init; in its NSObject super class. /// llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() { CGObjCRuntime &Runtime = CGM.getObjCRuntime(); llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(*this); // [NSAutoreleasePool alloc] IdentifierInfo *II = &CGM.getContext().Idents.get("alloc"); Selector AllocSel = getContext().Selectors.getSelector(0, &II); CallArgList Args; RValue AllocRV = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), getContext().getObjCIdType(), AllocSel, Receiver, Args); // [Receiver init] Receiver = AllocRV.getScalarVal(); II = &CGM.getContext().Idents.get("init"); Selector InitSel = getContext().Selectors.getSelector(0, &II); RValue InitRV = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), getContext().getObjCIdType(), InitSel, Receiver, Args); return InitRV.getScalarVal(); } /// Produce the code to do a primitive release. /// [tmp drain]; void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) { IdentifierInfo *II = &CGM.getContext().Idents.get("drain"); Selector DrainSel = getContext().Selectors.getSelector(0, &II); CallArgList Args; CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), getContext().VoidTy, DrainSel, Arg, Args); } void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF, Address addr, QualType type) { CGF.EmitARCDestroyStrong(addr, ARCPreciseLifetime); } void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF, Address addr, QualType type) { CGF.EmitARCDestroyStrong(addr, ARCImpreciseLifetime); } void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF, Address addr, QualType type) { CGF.EmitARCDestroyWeak(addr); } namespace { struct CallObjCAutoreleasePoolObject final : EHScopeStack::Cleanup { llvm::Value *Token; CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {} void Emit(CodeGenFunction &CGF, Flags flags) override { CGF.EmitObjCAutoreleasePoolPop(Token); } }; struct CallObjCMRRAutoreleasePoolObject final : EHScopeStack::Cleanup { llvm::Value *Token; CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {} void Emit(CodeGenFunction &CGF, Flags flags) override { CGF.EmitObjCMRRAutoreleasePoolPop(Token); } }; } void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) { if (CGM.getLangOpts().ObjCAutoRefCount) EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr); else EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr); } static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF, LValue lvalue, QualType type) { switch (type.getObjCLifetime()) { case Qualifiers::OCL_None: case Qualifiers::OCL_ExplicitNone: case Qualifiers::OCL_Strong: case Qualifiers::OCL_Autoreleasing: return TryEmitResult(CGF.EmitLoadOfLValue(lvalue, SourceLocation()).getScalarVal(), false); case Qualifiers::OCL_Weak: return TryEmitResult(CGF.EmitARCLoadWeakRetained(lvalue.getAddress()), true); } llvm_unreachable("impossible lifetime!"); } static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF, const Expr *e) { e = e->IgnoreParens(); QualType type = e->getType(); // If we're loading retained from a __strong xvalue, we can avoid // an extra retain/release pair by zeroing out the source of this // "move" operation. if (e->isXValue() && !type.isConstQualified() && type.getObjCLifetime() == Qualifiers::OCL_Strong) { // Emit the lvalue. LValue lv = CGF.EmitLValue(e); // Load the object pointer. llvm::Value *result = CGF.EmitLoadOfLValue(lv, SourceLocation()).getScalarVal(); // Set the source pointer to NULL. CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress()), lv); return TryEmitResult(result, true); } // As a very special optimization, in ARC++, if the l-value is the // result of a non-volatile assignment, do a simple retain of the // result of the call to objc_storeWeak instead of reloading. if (CGF.getLangOpts().CPlusPlus && !type.isVolatileQualified() && type.getObjCLifetime() == Qualifiers::OCL_Weak && isa<BinaryOperator>(e) && cast<BinaryOperator>(e)->getOpcode() == BO_Assign) return TryEmitResult(CGF.EmitScalarExpr(e), false); return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type); } typedef llvm::function_ref<llvm::Value *(CodeGenFunction &CGF, llvm::Value *value)> ValueTransform; /// Insert code immediately after a call. static llvm::Value *emitARCOperationAfterCall(CodeGenFunction &CGF, llvm::Value *value, ValueTransform doAfterCall, ValueTransform doFallback) { if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) { CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP(); // Place the retain immediately following the call. CGF.Builder.SetInsertPoint(call->getParent(), ++llvm::BasicBlock::iterator(call)); value = doAfterCall(CGF, value); CGF.Builder.restoreIP(ip); return value; } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) { CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP(); // Place the retain at the beginning of the normal destination block. llvm::BasicBlock *BB = invoke->getNormalDest(); CGF.Builder.SetInsertPoint(BB, BB->begin()); value = doAfterCall(CGF, value); CGF.Builder.restoreIP(ip); return value; // Bitcasts can arise because of related-result returns. Rewrite // the operand. } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) { llvm::Value *operand = bitcast->getOperand(0); operand = emitARCOperationAfterCall(CGF, operand, doAfterCall, doFallback); bitcast->setOperand(0, operand); return bitcast; // Generic fall-back case. } else { // Retain using the non-block variant: we never need to do a copy // of a block that's been returned to us. return doFallback(CGF, value); } } /// Given that the given expression is some sort of call (which does /// not return retained), emit a retain following it. static llvm::Value *emitARCRetainCallResult(CodeGenFunction &CGF, const Expr *e) { llvm::Value *value = CGF.EmitScalarExpr(e); return emitARCOperationAfterCall(CGF, value, [](CodeGenFunction &CGF, llvm::Value *value) { return CGF.EmitARCRetainAutoreleasedReturnValue(value); }, [](CodeGenFunction &CGF, llvm::Value *value) { return CGF.EmitARCRetainNonBlock(value); }); } /// Given that the given expression is some sort of call (which does /// not return retained), perform an unsafeClaim following it. static llvm::Value *emitARCUnsafeClaimCallResult(CodeGenFunction &CGF, const Expr *e) { llvm::Value *value = CGF.EmitScalarExpr(e); return emitARCOperationAfterCall(CGF, value, [](CodeGenFunction &CGF, llvm::Value *value) { return CGF.EmitARCUnsafeClaimAutoreleasedReturnValue(value); }, [](CodeGenFunction &CGF, llvm::Value *value) { return value; }); } llvm::Value *CodeGenFunction::EmitARCReclaimReturnedObject(const Expr *E, bool allowUnsafeClaim) { if (allowUnsafeClaim && CGM.getLangOpts().ObjCRuntime.hasARCUnsafeClaimAutoreleasedReturnValue()) { return emitARCUnsafeClaimCallResult(*this, E); } else { llvm::Value *value = emitARCRetainCallResult(*this, E); return EmitObjCConsumeObject(E->getType(), value); } } /// Determine whether it might be important to emit a separate /// objc_retain_block on the result of the given expression, or /// whether it's okay to just emit it in a +1 context. static bool shouldEmitSeparateBlockRetain(const Expr *e) { assert(e->getType()->isBlockPointerType()); e = e->IgnoreParens(); // For future goodness, emit block expressions directly in +1 // contexts if we can. if (isa<BlockExpr>(e)) return false; if (const CastExpr *cast = dyn_cast<CastExpr>(e)) { switch (cast->getCastKind()) { // Emitting these operations in +1 contexts is goodness. case CK_LValueToRValue: case CK_ARCReclaimReturnedObject: case CK_ARCConsumeObject: case CK_ARCProduceObject: return false; // These operations preserve a block type. case CK_NoOp: case CK_BitCast: return shouldEmitSeparateBlockRetain(cast->getSubExpr()); // These operations are known to be bad (or haven't been considered). case CK_AnyPointerToBlockPointerCast: default: return true; } } return true; } namespace { /// A CRTP base class for emitting expressions of retainable object /// pointer type in ARC. template <typename Impl, typename Result> class ARCExprEmitter { protected: CodeGenFunction &CGF; Impl &asImpl() { return *static_cast<Impl*>(this); } ARCExprEmitter(CodeGenFunction &CGF) : CGF(CGF) {} public: Result visit(const Expr *e); Result visitCastExpr(const CastExpr *e); Result visitPseudoObjectExpr(const PseudoObjectExpr *e); Result visitBinaryOperator(const BinaryOperator *e); Result visitBinAssign(const BinaryOperator *e); Result visitBinAssignUnsafeUnretained(const BinaryOperator *e); Result visitBinAssignAutoreleasing(const BinaryOperator *e); Result visitBinAssignWeak(const BinaryOperator *e); Result visitBinAssignStrong(const BinaryOperator *e); // Minimal implementation: // Result visitLValueToRValue(const Expr *e) // Result visitConsumeObject(const Expr *e) // Result visitExtendBlockObject(const Expr *e) // Result visitReclaimReturnedObject(const Expr *e) // Result visitCall(const Expr *e) // Result visitExpr(const Expr *e) // // Result emitBitCast(Result result, llvm::Type *resultType) // llvm::Value *getValueOfResult(Result result) }; } /// Try to emit a PseudoObjectExpr under special ARC rules. /// /// This massively duplicates emitPseudoObjectRValue. template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitPseudoObjectExpr(const PseudoObjectExpr *E) { SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques; // Find the result expression. const Expr *resultExpr = E->getResultExpr(); assert(resultExpr); Result result; for (PseudoObjectExpr::const_semantics_iterator i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) { const Expr *semantic = *i; // If this semantic expression is an opaque value, bind it // to the result of its source expression. if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) { typedef CodeGenFunction::OpaqueValueMappingData OVMA; OVMA opaqueData; // If this semantic is the result of the pseudo-object // expression, try to evaluate the source as +1. if (ov == resultExpr) { assert(!OVMA::shouldBindAsLValue(ov)); result = asImpl().visit(ov->getSourceExpr()); opaqueData = OVMA::bind(CGF, ov, RValue::get(asImpl().getValueOfResult(result))); // Otherwise, just bind it. } else { opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr()); } opaques.push_back(opaqueData); // Otherwise, if the expression is the result, evaluate it // and remember the result. } else if (semantic == resultExpr) { result = asImpl().visit(semantic); // Otherwise, evaluate the expression in an ignored context. } else { CGF.EmitIgnoredExpr(semantic); } } // Unbind all the opaques now. for (unsigned i = 0, e = opaques.size(); i != e; ++i) opaques[i].unbind(CGF); return result; } template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitCastExpr(const CastExpr *e) { switch (e->getCastKind()) { // No-op casts don't change the type, so we just ignore them. case CK_NoOp: return asImpl().visit(e->getSubExpr()); // These casts can change the type. case CK_CPointerToObjCPointerCast: case CK_BlockPointerToObjCPointerCast: case CK_AnyPointerToBlockPointerCast: case CK_BitCast: { llvm::Type *resultType = CGF.ConvertType(e->getType()); assert(e->getSubExpr()->getType()->hasPointerRepresentation()); Result result = asImpl().visit(e->getSubExpr()); return asImpl().emitBitCast(result, resultType); } // Handle some casts specially. case CK_LValueToRValue: return asImpl().visitLValueToRValue(e->getSubExpr()); case CK_ARCConsumeObject: return asImpl().visitConsumeObject(e->getSubExpr()); case CK_ARCExtendBlockObject: return asImpl().visitExtendBlockObject(e->getSubExpr()); case CK_ARCReclaimReturnedObject: return asImpl().visitReclaimReturnedObject(e->getSubExpr()); // Otherwise, use the default logic. default: return asImpl().visitExpr(e); } } template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitBinaryOperator(const BinaryOperator *e) { switch (e->getOpcode()) { case BO_Comma: CGF.EmitIgnoredExpr(e->getLHS()); CGF.EnsureInsertPoint(); return asImpl().visit(e->getRHS()); case BO_Assign: return asImpl().visitBinAssign(e); default: return asImpl().visitExpr(e); } } template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitBinAssign(const BinaryOperator *e) { switch (e->getLHS()->getType().getObjCLifetime()) { case Qualifiers::OCL_ExplicitNone: return asImpl().visitBinAssignUnsafeUnretained(e); case Qualifiers::OCL_Weak: return asImpl().visitBinAssignWeak(e); case Qualifiers::OCL_Autoreleasing: return asImpl().visitBinAssignAutoreleasing(e); case Qualifiers::OCL_Strong: return asImpl().visitBinAssignStrong(e); case Qualifiers::OCL_None: return asImpl().visitExpr(e); } llvm_unreachable("bad ObjC ownership qualifier"); } /// The default rule for __unsafe_unretained emits the RHS recursively, /// stores into the unsafe variable, and propagates the result outward. template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>:: visitBinAssignUnsafeUnretained(const BinaryOperator *e) { // Recursively emit the RHS. // For __block safety, do this before emitting the LHS. Result result = asImpl().visit(e->getRHS()); // Perform the store. LValue lvalue = CGF.EmitCheckedLValue(e->getLHS(), CodeGenFunction::TCK_Store); CGF.EmitStoreThroughLValue(RValue::get(asImpl().getValueOfResult(result)), lvalue); return result; } template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitBinAssignAutoreleasing(const BinaryOperator *e) { return asImpl().visitExpr(e); } template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitBinAssignWeak(const BinaryOperator *e) { return asImpl().visitExpr(e); } template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visitBinAssignStrong(const BinaryOperator *e) { return asImpl().visitExpr(e); } /// The general expression-emission logic. template <typename Impl, typename Result> Result ARCExprEmitter<Impl,Result>::visit(const Expr *e) { // We should *never* see a nested full-expression here, because if // we fail to emit at +1, our caller must not retain after we close // out the full-expression. This isn't as important in the unsafe // emitter. assert(!isa<ExprWithCleanups>(e)); // Look through parens, __extension__, generic selection, etc. e = e->IgnoreParens(); // Handle certain kinds of casts. if (const CastExpr *ce = dyn_cast<CastExpr>(e)) { return asImpl().visitCastExpr(ce); // Handle the comma operator. } else if (auto op = dyn_cast<BinaryOperator>(e)) { return asImpl().visitBinaryOperator(op); // TODO: handle conditional operators here // For calls and message sends, use the retained-call logic. // Delegate inits are a special case in that they're the only // returns-retained expression that *isn't* surrounded by // a consume. } else if (isa<CallExpr>(e) || (isa<ObjCMessageExpr>(e) && !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) { return asImpl().visitCall(e); // Look through pseudo-object expressions. } else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) { return asImpl().visitPseudoObjectExpr(pseudo); } return asImpl().visitExpr(e); } namespace { /// An emitter for +1 results. struct ARCRetainExprEmitter : public ARCExprEmitter<ARCRetainExprEmitter, TryEmitResult> { ARCRetainExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {} llvm::Value *getValueOfResult(TryEmitResult result) { return result.getPointer(); } TryEmitResult emitBitCast(TryEmitResult result, llvm::Type *resultType) { llvm::Value *value = result.getPointer(); value = CGF.Builder.CreateBitCast(value, resultType); result.setPointer(value); return result; } TryEmitResult visitLValueToRValue(const Expr *e) { return tryEmitARCRetainLoadOfScalar(CGF, e); } /// For consumptions, just emit the subexpression and thus elide /// the retain/release pair. TryEmitResult visitConsumeObject(const Expr *e) { llvm::Value *result = CGF.EmitScalarExpr(e); return TryEmitResult(result, true); } /// Block extends are net +0. Naively, we could just recurse on /// the subexpression, but actually we need to ensure that the /// value is copied as a block, so there's a little filter here. TryEmitResult visitExtendBlockObject(const Expr *e) { llvm::Value *result; // will be a +0 value // If we can't safely assume the sub-expression will produce a // block-copied value, emit the sub-expression at +0. if (shouldEmitSeparateBlockRetain(e)) { result = CGF.EmitScalarExpr(e); // Otherwise, try to emit the sub-expression at +1 recursively. } else { TryEmitResult subresult = asImpl().visit(e); // If that produced a retained value, just use that. if (subresult.getInt()) { return subresult; } // Otherwise it's +0. result = subresult.getPointer(); } // Retain the object as a block. result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true); return TryEmitResult(result, true); } /// For reclaims, emit the subexpression as a retained call and /// skip the consumption. TryEmitResult visitReclaimReturnedObject(const Expr *e) { llvm::Value *result = emitARCRetainCallResult(CGF, e); return TryEmitResult(result, true); } /// When we have an undecorated call, retroactively do a claim. TryEmitResult visitCall(const Expr *e) { llvm::Value *result = emitARCRetainCallResult(CGF, e); return TryEmitResult(result, true); } // TODO: maybe special-case visitBinAssignWeak? TryEmitResult visitExpr(const Expr *e) { // We didn't find an obvious production, so emit what we've got and // tell the caller that we didn't manage to retain. llvm::Value *result = CGF.EmitScalarExpr(e); return TryEmitResult(result, false); } }; } static TryEmitResult tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) { return ARCRetainExprEmitter(CGF).visit(e); } static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF, LValue lvalue, QualType type) { TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type); llvm::Value *value = result.getPointer(); if (!result.getInt()) value = CGF.EmitARCRetain(type, value); return value; } /// EmitARCRetainScalarExpr - Semantically equivalent to /// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a /// best-effort attempt to peephole expressions that naturally produce /// retained objects. llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) { // The retain needs to happen within the full-expression. if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) { enterFullExpression(cleanups); RunCleanupsScope scope(*this); return EmitARCRetainScalarExpr(cleanups->getSubExpr()); } TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e); llvm::Value *value = result.getPointer(); if (!result.getInt()) value = EmitARCRetain(e->getType(), value); return value; } llvm::Value * CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) { // The retain needs to happen within the full-expression. if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) { enterFullExpression(cleanups); RunCleanupsScope scope(*this); return EmitARCRetainAutoreleaseScalarExpr(cleanups->getSubExpr()); } TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e); llvm::Value *value = result.getPointer(); if (result.getInt()) value = EmitARCAutorelease(value); else value = EmitARCRetainAutorelease(e->getType(), value); return value; } llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) { llvm::Value *result; bool doRetain; if (shouldEmitSeparateBlockRetain(e)) { result = EmitScalarExpr(e); doRetain = true; } else { TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e); result = subresult.getPointer(); doRetain = !subresult.getInt(); } if (doRetain) result = EmitARCRetainBlock(result, /*mandatory*/ true); return EmitObjCConsumeObject(e->getType(), result); } llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) { // In ARC, retain and autorelease the expression. if (getLangOpts().ObjCAutoRefCount) { // Do so before running any cleanups for the full-expression. // EmitARCRetainAutoreleaseScalarExpr does this for us. return EmitARCRetainAutoreleaseScalarExpr(expr); } // Otherwise, use the normal scalar-expression emission. The // exception machinery doesn't do anything special with the // exception like retaining it, so there's no safety associated with // only running cleanups after the throw has started, and when it // matters it tends to be substantially inferior code. return EmitScalarExpr(expr); } namespace { /// An emitter for assigning into an __unsafe_unretained context. struct ARCUnsafeUnretainedExprEmitter : public ARCExprEmitter<ARCUnsafeUnretainedExprEmitter, llvm::Value*> { ARCUnsafeUnretainedExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {} llvm::Value *getValueOfResult(llvm::Value *value) { return value; } llvm::Value *emitBitCast(llvm::Value *value, llvm::Type *resultType) { return CGF.Builder.CreateBitCast(value, resultType); } llvm::Value *visitLValueToRValue(const Expr *e) { return CGF.EmitScalarExpr(e); } /// For consumptions, just emit the subexpression and perform the /// consumption like normal. llvm::Value *visitConsumeObject(const Expr *e) { llvm::Value *value = CGF.EmitScalarExpr(e); return CGF.EmitObjCConsumeObject(e->getType(), value); } /// No special logic for block extensions. (This probably can't /// actually happen in this emitter, though.) llvm::Value *visitExtendBlockObject(const Expr *e) { return CGF.EmitARCExtendBlockObject(e); } /// For reclaims, perform an unsafeClaim if that's enabled. llvm::Value *visitReclaimReturnedObject(const Expr *e) { return CGF.EmitARCReclaimReturnedObject(e, /*unsafe*/ true); } /// When we have an undecorated call, just emit it without adding /// the unsafeClaim. llvm::Value *visitCall(const Expr *e) { return CGF.EmitScalarExpr(e); } /// Just do normal scalar emission in the default case. llvm::Value *visitExpr(const Expr *e) { return CGF.EmitScalarExpr(e); } }; } static llvm::Value *emitARCUnsafeUnretainedScalarExpr(CodeGenFunction &CGF, const Expr *e) { return ARCUnsafeUnretainedExprEmitter(CGF).visit(e); } /// EmitARCUnsafeUnretainedScalarExpr - Semantically equivalent to /// immediately releasing the resut of EmitARCRetainScalarExpr, but /// avoiding any spurious retains, including by performing reclaims /// with objc_unsafeClaimAutoreleasedReturnValue. llvm::Value *CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr(const Expr *e) { // Look through full-expressions. if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) { enterFullExpression(cleanups); RunCleanupsScope scope(*this); return emitARCUnsafeUnretainedScalarExpr(*this, cleanups->getSubExpr()); } return emitARCUnsafeUnretainedScalarExpr(*this, e); } std::pair<LValue,llvm::Value*> CodeGenFunction::EmitARCStoreUnsafeUnretained(const BinaryOperator *e, bool ignored) { // Evaluate the RHS first. If we're ignoring the result, assume // that we can emit at an unsafe +0. llvm::Value *value; if (ignored) { value = EmitARCUnsafeUnretainedScalarExpr(e->getRHS()); } else { value = EmitScalarExpr(e->getRHS()); } // Emit the LHS and perform the store. LValue lvalue = EmitLValue(e->getLHS()); EmitStoreOfScalar(value, lvalue); return std::pair<LValue,llvm::Value*>(std::move(lvalue), value); } std::pair<LValue,llvm::Value*> CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e, bool ignored) { // Evaluate the RHS first. TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS()); llvm::Value *value = result.getPointer(); bool hasImmediateRetain = result.getInt(); // If we didn't emit a retained object, and the l-value is of block // type, then we need to emit the block-retain immediately in case // it invalidates the l-value. if (!hasImmediateRetain && e->getType()->isBlockPointerType()) { value = EmitARCRetainBlock(value, /*mandatory*/ false); hasImmediateRetain = true; } LValue lvalue = EmitLValue(e->getLHS()); // If the RHS was emitted retained, expand this. if (hasImmediateRetain) { llvm::Value *oldValue = EmitLoadOfScalar(lvalue, SourceLocation()); EmitStoreOfScalar(value, lvalue); EmitARCRelease(oldValue, lvalue.isARCPreciseLifetime()); } else { value = EmitARCStoreStrong(lvalue, value, ignored); } return std::pair<LValue,llvm::Value*>(lvalue, value); } std::pair<LValue,llvm::Value*> CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) { llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS()); LValue lvalue = EmitLValue(e->getLHS()); EmitStoreOfScalar(value, lvalue); return std::pair<LValue,llvm::Value*>(lvalue, value); } void CodeGenFunction::EmitObjCAutoreleasePoolStmt( const ObjCAutoreleasePoolStmt &ARPS) { const Stmt *subStmt = ARPS.getSubStmt(); const CompoundStmt &S = cast<CompoundStmt>(*subStmt); CGDebugInfo *DI = getDebugInfo(); if (DI) DI->EmitLexicalBlockStart(Builder, S.getLBracLoc()); // Keep track of the current cleanup stack depth. RunCleanupsScope Scope(*this); if (CGM.getLangOpts().ObjCRuntime.hasNativeARC()) { llvm::Value *token = EmitObjCAutoreleasePoolPush(); EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token); } else { llvm::Value *token = EmitObjCMRRAutoreleasePoolPush(); EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token); } for (const auto *I : S.body()) EmitStmt(I); if (DI) DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc()); } /// EmitExtendGCLifetime - Given a pointer to an Objective-C object, /// make sure it survives garbage collection until this point. void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) { // We just use an inline assembly. llvm::FunctionType *extenderType = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All); llvm::Value *extender = llvm::InlineAsm::get(extenderType, /* assembly */ "", /* constraints */ "r", /* side effects */ true); object = Builder.CreateBitCast(object, VoidPtrTy); EmitNounwindRuntimeCall(extender, object); } /// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with /// non-trivial copy assignment function, produce following helper function. /// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; } /// llvm::Constant * CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction( const ObjCPropertyImplDecl *PID) { if (!getLangOpts().CPlusPlus || !getLangOpts().ObjCRuntime.hasAtomicCopyHelper()) return nullptr; QualType Ty = PID->getPropertyIvarDecl()->getType(); if (!Ty->isRecordType()) return nullptr; const ObjCPropertyDecl *PD = PID->getPropertyDecl(); if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic))) return nullptr; llvm::Constant *HelperFn = nullptr; if (hasTrivialSetExpr(PID)) return nullptr; assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null"); if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty))) return HelperFn; ASTContext &C = getContext(); IdentifierInfo *II = &CGM.getContext().Idents.get("__assign_helper_atomic_property_"); FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II, C.VoidTy, nullptr, SC_Static, false, false); QualType DestTy = C.getPointerType(Ty); QualType SrcTy = Ty; SrcTy.addConst(); SrcTy = C.getPointerType(SrcTy); FunctionArgList args; ImplicitParamDecl dstDecl(getContext(), FD, SourceLocation(), nullptr,DestTy); args.push_back(&dstDecl); ImplicitParamDecl srcDecl(getContext(), FD, SourceLocation(), nullptr, SrcTy); args.push_back(&srcDecl); const CGFunctionInfo &FI = CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args); llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); llvm::Function *Fn = llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, "__assign_helper_atomic_property_", &CGM.getModule()); CGM.SetInternalFunctionAttributes(nullptr, Fn, FI); StartFunction(FD, C.VoidTy, Fn, FI, args); DeclRefExpr DstExpr(&dstDecl, false, DestTy, VK_RValue, SourceLocation()); UnaryOperator DST(&DstExpr, UO_Deref, DestTy->getPointeeType(), VK_LValue, OK_Ordinary, SourceLocation()); DeclRefExpr SrcExpr(&srcDecl, false, SrcTy, VK_RValue, SourceLocation()); UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(), VK_LValue, OK_Ordinary, SourceLocation()); Expr *Args[2] = { &DST, &SRC }; CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment()); CXXOperatorCallExpr TheCall(C, OO_Equal, CalleeExp->getCallee(), Args, DestTy->getPointeeType(), VK_LValue, SourceLocation(), false); EmitStmt(&TheCall); FinishFunction(); HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); CGM.setAtomicSetterHelperFnMap(Ty, HelperFn); return HelperFn; } llvm::Constant * CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction( const ObjCPropertyImplDecl *PID) { if (!getLangOpts().CPlusPlus || !getLangOpts().ObjCRuntime.hasAtomicCopyHelper()) return nullptr; const ObjCPropertyDecl *PD = PID->getPropertyDecl(); QualType Ty = PD->getType(); if (!Ty->isRecordType()) return nullptr; if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic))) return nullptr; llvm::Constant *HelperFn = nullptr; if (hasTrivialGetExpr(PID)) return nullptr; assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null"); if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty))) return HelperFn; ASTContext &C = getContext(); IdentifierInfo *II = &CGM.getContext().Idents.get("__copy_helper_atomic_property_"); FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II, C.VoidTy, nullptr, SC_Static, false, false); QualType DestTy = C.getPointerType(Ty); QualType SrcTy = Ty; SrcTy.addConst(); SrcTy = C.getPointerType(SrcTy); FunctionArgList args; ImplicitParamDecl dstDecl(getContext(), FD, SourceLocation(), nullptr,DestTy); args.push_back(&dstDecl); ImplicitParamDecl srcDecl(getContext(), FD, SourceLocation(), nullptr, SrcTy); args.push_back(&srcDecl); const CGFunctionInfo &FI = CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args); llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); llvm::Function *Fn = llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, "__copy_helper_atomic_property_", &CGM.getModule()); CGM.SetInternalFunctionAttributes(nullptr, Fn, FI); StartFunction(FD, C.VoidTy, Fn, FI, args); DeclRefExpr SrcExpr(&srcDecl, false, SrcTy, VK_RValue, SourceLocation()); UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(), VK_LValue, OK_Ordinary, SourceLocation()); CXXConstructExpr *CXXConstExpr = cast<CXXConstructExpr>(PID->getGetterCXXConstructor()); SmallVector<Expr*, 4> ConstructorArgs; ConstructorArgs.push_back(&SRC); ConstructorArgs.append(std::next(CXXConstExpr->arg_begin()), CXXConstExpr->arg_end()); CXXConstructExpr *TheCXXConstructExpr = CXXConstructExpr::Create(C, Ty, SourceLocation(), CXXConstExpr->getConstructor(), CXXConstExpr->isElidable(), ConstructorArgs, CXXConstExpr->hadMultipleCandidates(), CXXConstExpr->isListInitialization(), CXXConstExpr->isStdInitListInitialization(), CXXConstExpr->requiresZeroInitialization(), CXXConstExpr->getConstructionKind(), SourceRange()); DeclRefExpr DstExpr(&dstDecl, false, DestTy, VK_RValue, SourceLocation()); RValue DV = EmitAnyExpr(&DstExpr); CharUnits Alignment = getContext().getTypeAlignInChars(TheCXXConstructExpr->getType()); EmitAggExpr(TheCXXConstructExpr, AggValueSlot::forAddr(Address(DV.getScalarVal(), Alignment), Qualifiers(), AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased)); FinishFunction(); HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); CGM.setAtomicGetterHelperFnMap(Ty, HelperFn); return HelperFn; } llvm::Value * CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) { // Get selectors for retain/autorelease. IdentifierInfo *CopyID = &getContext().Idents.get("copy"); Selector CopySelector = getContext().Selectors.getNullarySelector(CopyID); IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease"); Selector AutoreleaseSelector = getContext().Selectors.getNullarySelector(AutoreleaseID); // Emit calls to retain/autorelease. CGObjCRuntime &Runtime = CGM.getObjCRuntime(); llvm::Value *Val = Block; RValue Result; Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), Ty, CopySelector, Val, CallArgList(), nullptr, nullptr); Val = Result.getScalarVal(); Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), Ty, AutoreleaseSelector, Val, CallArgList(), nullptr, nullptr); Val = Result.getScalarVal(); return Val; } CGObjCRuntime::~CGObjCRuntime() {}