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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGObjC.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGObjC.cpp | 3468 |
1 files changed, 3468 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGObjC.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGObjC.cpp new file mode 100644 index 000000000000..f4fbab3c2b83 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGObjC.cpp @@ -0,0 +1,3468 @@ +//===---- CGObjC.cpp - Emit LLVM Code for Objective-C ---------------------===// +// +// 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); + + // Optimize empty collections by referencing constants, when available. + uint64_t NumElements = + ALE ? ALE->getNumElements() : DLE->getNumElements(); + if (NumElements == 0 && CGM.getLangOpts().ObjCRuntime.hasEmptyCollections()) { + StringRef ConstantName = ALE ? "__NSArray0__" : "__NSDictionary0__"; + QualType IdTy(CGM.getContext().getObjCIdType()); + llvm::Constant *Constant = + CGM.CreateRuntimeVariable(ConvertType(IdTy), ConstantName); + LValue LV = MakeNaturalAlignAddrLValue(Constant, IdTy); + llvm::Value *Ptr = EmitLoadOfScalar(LV, E->getLocStart()); + cast<llvm::LoadInst>(Ptr)->setMetadata( + CGM.getModule().getMDKindID("invariant.load"), + llvm::MDNode::get(getLLVMContext(), None)); + return Builder.CreateBitCast(Ptr, ConvertType(E->getType())); + } + + // Compute the type of the array we're initializing. + 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(), /*AC*/AbstractCallee(method)); + + // 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::Constant *fn = CGF.CGM.getObjCRuntime().GetGetStructFunction(); + CGCallee callee = CGCallee::forDirect(fn); + CGF.EmitCall(CGF.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, args), + callee, 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::Constant *copyCppAtomicObjectFn = + CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction(); + CGCallee callee = CGCallee::forDirect(copyCppAtomicObjectFn); + CGF.EmitCall( + CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args), + callee, 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::Constant *getPropertyFn = + CGM.getObjCRuntime().GetPropertyGetFunction(); + if (!getPropertyFn) { + CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy"); + return; + } + CGCallee callee = CGCallee::forDirect(getPropertyFn); + + // 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), + callee, ReturnValueSlot(), args, &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::Constant *fn = CGF.CGM.getObjCRuntime().GetSetStructFunction(); + CGCallee callee = CGCallee::forDirect(fn); + CGF.EmitCall( + CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args), + callee, 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::Constant *fn = + CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction(); + CGCallee callee = CGCallee::forDirect(fn); + CGF.EmitCall( + CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args), + callee, 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::Constant *setOptimizedPropertyFn = nullptr; + llvm::Constant *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()); + CGCallee callee = CGCallee::forDirect(setOptimizedPropertyFn); + EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args), + callee, 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. + CGCallee callee = CGCallee::forDirect(setPropertyFn); + EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args), + callee, 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(), FPOptions()); + 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 *EnumerationMutationFnPtr = + CGM.getObjCRuntime().EnumerationMutationFunction(); + if (!EnumerationMutationFnPtr) { + CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime"); + return; + } + CGCallee EnumerationMutationFn = + CGCallee::forDirect(EnumerationMutationFnPtr); + + CGDebugInfo *DI = getDebugInfo(); + if (DI) + DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin()); + + RunCleanupsScope ForScope(*this); + + // 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"); + + // 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 { + EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue, + /*isInit*/ true); + } + + // 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 bool IsForwarding(StringRef Name) { + return llvm::StringSwitch<bool>(Name) + .Cases("objc_autoreleaseReturnValue", // ARCInstKind::AutoreleaseRV + "objc_autorelease", // ARCInstKind::Autorelease + "objc_retainAutoreleaseReturnValue", // ARCInstKind::FusedRetainAutoreleaseRV + "objc_retainAutoreleasedReturnValue", // ARCInstKind::RetainRV + "objc_retainAutorelease", // ARCInstKind::FusedRetainAutorelease + "objc_retainedObject", // ARCInstKind::NoopCast + "objc_retain", // ARCInstKind::Retain + "objc_unretainedObject", // ARCInstKind::NoopCast + "objc_unretainedPointer", // ARCInstKind::NoopCast + "objc_unsafeClaimAutoreleasedReturnValue", // ARCInstKind::ClaimRV + true) + .Default(false); +} + +static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM, + llvm::FunctionType *FTy, + StringRef Name) { + llvm::Constant *RTF = CGM.CreateRuntimeFunction(FTy, Name); + + if (auto *F = dyn_cast<llvm::Function>(RTF)) { + // 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() && + !CGM.getTriple().isOSBinFormatCOFF()) { + F->setLinkage(llvm::Function::ExternalWeakLinkage); + } else if (Name == "objc_retain" || Name == "objc_release") { + // If we have Native ARC, set nonlazybind attribute for these APIs for + // performance. + F->addFnAttr(llvm::Attribute::NonLazyBind); + } + + if (IsForwarding(Name)) + F->arg_begin()->addAttr(llvm::Attribute::Returned); + } + + return RTF; +} + +/// 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); +} + +void CodeGenFunction::emitARCIntrinsicUse(CodeGenFunction &CGF, Address addr, + QualType type) { + llvm::Value *value = CGF.Builder.CreateLoad(addr); + CGF.EmitARCIntrinsicUse(value); +} + +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(), FPOptions()); + + 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; +} + +llvm::Value * +CodeGenFunction::EmitBuiltinAvailable(ArrayRef<llvm::Value *> Args) { + assert(Args.size() == 3 && "Expected 3 argument here!"); + + if (!CGM.IsOSVersionAtLeastFn) { + llvm::FunctionType *FTy = + llvm::FunctionType::get(Int32Ty, {Int32Ty, Int32Ty, Int32Ty}, false); + CGM.IsOSVersionAtLeastFn = + CGM.CreateRuntimeFunction(FTy, "__isOSVersionAtLeast"); + } + + llvm::Value *CallRes = + EmitNounwindRuntimeCall(CGM.IsOSVersionAtLeastFn, Args); + + return Builder.CreateICmpNE(CallRes, llvm::Constant::getNullValue(Int32Ty)); +} + +void CodeGenModule::emitAtAvailableLinkGuard() { + if (!IsOSVersionAtLeastFn) + return; + // @available requires CoreFoundation only on Darwin. + if (!Target.getTriple().isOSDarwin()) + return; + // Add -framework CoreFoundation to the linker commands. We still want to + // emit the core foundation reference down below because otherwise if + // CoreFoundation is not used in the code, the linker won't link the + // framework. + auto &Context = getLLVMContext(); + llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"), + llvm::MDString::get(Context, "CoreFoundation")}; + LinkerOptionsMetadata.push_back(llvm::MDNode::get(Context, Args)); + // Emit a reference to a symbol from CoreFoundation to ensure that + // CoreFoundation is linked into the final binary. + llvm::FunctionType *FTy = + llvm::FunctionType::get(Int32Ty, {VoidPtrTy}, false); + llvm::Constant *CFFunc = + CreateRuntimeFunction(FTy, "CFBundleGetVersionNumber"); + + llvm::FunctionType *CheckFTy = llvm::FunctionType::get(VoidTy, {}, false); + llvm::Function *CFLinkCheckFunc = cast<llvm::Function>(CreateBuiltinFunction( + CheckFTy, "__clang_at_available_requires_core_foundation_framework")); + CFLinkCheckFunc->setLinkage(llvm::GlobalValue::LinkOnceAnyLinkage); + CFLinkCheckFunc->setVisibility(llvm::GlobalValue::HiddenVisibility); + CodeGenFunction CGF(*this); + CGF.Builder.SetInsertPoint(CGF.createBasicBlock("", CFLinkCheckFunc)); + CGF.EmitNounwindRuntimeCall(CFFunc, llvm::Constant::getNullValue(VoidPtrTy)); + CGF.Builder.CreateUnreachable(); + addCompilerUsedGlobal(CFLinkCheckFunc); +} + +CGObjCRuntime::~CGObjCRuntime() {} |