| //===--- GenMeta.cpp - IR generation for metadata constructs --------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements IR generation for type metadata constructs. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "swift/ABI/MetadataValues.h" |
| #include "swift/AST/ASTContext.h" |
| #include "swift/AST/CanTypeVisitor.h" |
| #include "swift/AST/ExistentialLayout.h" |
| #include "swift/AST/Decl.h" |
| #include "swift/AST/Attr.h" |
| #include "swift/AST/IRGenOptions.h" |
| #include "swift/AST/SubstitutionMap.h" |
| #include "swift/AST/Types.h" |
| #include "swift/ClangImporter/ClangModule.h" |
| #include "swift/IRGen/Linking.h" |
| #include "swift/Runtime/Metadata.h" |
| #include "swift/SIL/FormalLinkage.h" |
| #include "swift/SIL/SILModule.h" |
| #include "swift/SIL/TypeLowering.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/IR/DerivedTypes.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/GlobalVariable.h" |
| #include "llvm/IR/Module.h" |
| |
| #include "Address.h" |
| #include "Callee.h" |
| #include "ClassMetadataVisitor.h" |
| #include "ConstantBuilder.h" |
| #include "EnumMetadataVisitor.h" |
| #include "FixedTypeInfo.h" |
| #include "GenArchetype.h" |
| #include "GenClass.h" |
| #include "GenDecl.h" |
| #include "GenPoly.h" |
| #include "GenStruct.h" |
| #include "GenValueWitness.h" |
| #include "HeapTypeInfo.h" |
| #include "IRGenDebugInfo.h" |
| #include "IRGenMangler.h" |
| #include "IRGenModule.h" |
| #include "MetadataLayout.h" |
| #include "ProtocolInfo.h" |
| #include "ScalarTypeInfo.h" |
| #include "StructLayout.h" |
| #include "StructMetadataVisitor.h" |
| |
| #include "GenMeta.h" |
| |
| using namespace swift; |
| using namespace irgen; |
| |
| static Address emitAddressOfMetadataSlotAtIndex(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| int index, |
| llvm::Type *objectTy) { |
| // Require the metadata to be some type that we recognize as a |
| // metadata pointer. |
| assert(metadata->getType() == IGF.IGM.TypeMetadataPtrTy); |
| |
| return IGF.emitAddressAtOffset(metadata, |
| Offset(index * IGF.IGM.getPointerSize()), |
| objectTy, IGF.IGM.getPointerAlignment()); |
| } |
| |
| /// Emit a load from the given metadata at a constant index. |
| static llvm::LoadInst *emitLoadFromMetadataAtIndex(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| int index, |
| llvm::Type *objectTy, |
| const llvm::Twine &suffix = "") { |
| Address slot = |
| emitAddressOfMetadataSlotAtIndex(IGF, metadata, index, objectTy); |
| |
| // Load. |
| return IGF.Builder.CreateLoad(slot, metadata->getName() + suffix); |
| } |
| |
| static Address createPointerSizedGEP(IRGenFunction &IGF, |
| Address base, |
| Size offset) { |
| return IGF.Builder.CreateConstArrayGEP(base, |
| IGF.IGM.getOffsetInWords(offset), |
| offset); |
| } |
| |
| // FIXME: willBeRelativelyAddressed is only needed to work around an ld64 bug |
| // resolving relative references to coalesceable symbols. |
| // It should be removed when fixed. rdar://problem/22674524 |
| static llvm::Constant *getMangledTypeName(IRGenModule &IGM, CanType type, |
| bool willBeRelativelyAddressed = false) { |
| IRGenMangler Mangler; |
| std::string Name = Mangler.mangleTypeForMetadata(type); |
| return IGM.getAddrOfGlobalString(Name, willBeRelativelyAddressed); |
| } |
| |
| llvm::Value *irgen::emitObjCMetadataRefForMetadata(IRGenFunction &IGF, |
| llvm::Value *classPtr) { |
| assert(IGF.IGM.Context.LangOpts.EnableObjCInterop); |
| classPtr = IGF.Builder.CreateBitCast(classPtr, IGF.IGM.ObjCClassPtrTy); |
| |
| // Fetch the metadata for that class. |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetObjCClassMetadataFn(), |
| classPtr); |
| call->setDoesNotThrow(); |
| call->setDoesNotAccessMemory(); |
| return call; |
| } |
| |
| /// Emit a reference to the Swift metadata for an Objective-C class. |
| static llvm::Value *emitObjCMetadataRef(IRGenFunction &IGF, |
| ClassDecl *theClass) { |
| // Derive a pointer to the Objective-C class. |
| auto classPtr = emitObjCHeapMetadataRef(IGF, theClass); |
| |
| return emitObjCMetadataRefForMetadata(IGF, classPtr); |
| } |
| |
| namespace { |
| /// A structure for collecting generic arguments for emitting a |
| /// nominal metadata reference. The structure produced here is |
| /// consumed by swift_getGenericMetadata() and must correspond to |
| /// the fill operations that the compiler emits for the bound decl. |
| struct GenericArguments { |
| /// The values to use to initialize the arguments structure. |
| SmallVector<llvm::Value *, 8> Values; |
| SmallVector<llvm::Type *, 8> Types; |
| |
| static unsigned getNumGenericArguments(IRGenModule &IGM, |
| NominalTypeDecl *nominal) { |
| GenericTypeRequirements requirements(IGM, nominal); |
| return requirements.getNumTypeRequirements(); |
| } |
| |
| void collectTypes(IRGenModule &IGM, NominalTypeDecl *nominal) { |
| GenericTypeRequirements requirements(IGM, nominal); |
| collectTypes(IGM, requirements); |
| } |
| |
| void collectTypes(IRGenModule &IGM, |
| const GenericTypeRequirements &requirements) { |
| for (auto &requirement : requirements.getRequirements()) { |
| if (requirement.Protocol) { |
| Types.push_back(IGM.WitnessTablePtrTy); |
| } else { |
| Types.push_back(IGM.TypeMetadataPtrTy); |
| } |
| } |
| } |
| |
| void collect(IRGenFunction &IGF, CanType type) { |
| auto *decl = type.getNominalOrBoundGenericNominal(); |
| GenericTypeRequirements requirements(IGF.IGM, decl); |
| |
| auto subs = |
| type->getContextSubstitutionMap(IGF.IGM.getSwiftModule(), decl); |
| requirements.enumerateFulfillments(IGF.IGM, subs, |
| [&](unsigned reqtIndex, CanType type, |
| Optional<ProtocolConformanceRef> conf) { |
| if (conf) { |
| Values.push_back(emitWitnessTableRef(IGF, type, *conf)); |
| } else { |
| Values.push_back(IGF.emitTypeMetadataRef(type)); |
| } |
| }); |
| |
| collectTypes(IGF.IGM, decl); |
| assert(Types.size() == Values.size()); |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// Given an array of polymorphic arguments as might be set up by |
| /// GenericArguments, bind the polymorphic parameters. |
| static void emitPolymorphicParametersFromArray(IRGenFunction &IGF, |
| NominalTypeDecl *typeDecl, |
| Address array) { |
| GenericTypeRequirements requirements(IGF.IGM, typeDecl); |
| |
| array = IGF.Builder.CreateElementBitCast(array, IGF.IGM.TypeMetadataPtrTy); |
| |
| auto getInContext = [&](CanType type) -> CanType { |
| return typeDecl->mapTypeIntoContext(type) |
| ->getCanonicalType(); |
| }; |
| |
| // Okay, bind everything else from the context. |
| requirements.bindFromBuffer(IGF, array, getInContext); |
| } |
| |
| static bool isTypeErasedGenericClass(NominalTypeDecl *ntd) { |
| // ObjC classes are type erased. |
| // TODO: Unless they have magic methods... |
| if (auto clas = dyn_cast<ClassDecl>(ntd)) |
| return clas->hasClangNode() && clas->isGenericContext(); |
| return false; |
| } |
| |
| static bool isTypeErasedGenericClassType(CanType type) { |
| if (auto nom = type->getAnyNominal()) |
| return isTypeErasedGenericClass(nom); |
| return false; |
| } |
| |
| // Get the type that exists at runtime to represent a compile-time type. |
| CanType |
| irgen::getRuntimeReifiedType(IRGenModule &IGM, CanType type) { |
| return CanType(type.transform([&](Type t) -> Type { |
| if (isTypeErasedGenericClassType(CanType(t))) { |
| return t->getAnyNominal()->getDeclaredType()->getCanonicalType(); |
| } |
| return t; |
| })); |
| } |
| |
| /// Attempts to return a constant heap metadata reference for a |
| /// class type. This is generally only valid for specific kinds of |
| /// ObjC reference, like superclasses or category references. |
| llvm::Constant *irgen::tryEmitConstantHeapMetadataRef(IRGenModule &IGM, |
| CanType type, |
| bool allowDynamicUninitialized) { |
| auto theDecl = type->getClassOrBoundGenericClass(); |
| assert(theDecl && "emitting constant heap metadata ref for non-class type?"); |
| |
| // If the class must not require dynamic initialization --- e.g. if it |
| // is a super reference --- then respect everything that might impose that. |
| if (!allowDynamicUninitialized) { |
| if (doesClassMetadataRequireDynamicInitialization(IGM, theDecl)) |
| return nullptr; |
| |
| // Otherwise, just respect genericity. |
| } else if (theDecl->isGenericContext() && !isTypeErasedGenericClass(theDecl)){ |
| return nullptr; |
| } |
| |
| // For imported classes, use the ObjC class symbol. |
| // This incidentally cannot coincide with most of the awkward cases, like |
| // having parent metadata. |
| if (!hasKnownSwiftMetadata(IGM, theDecl)) |
| return IGM.getAddrOfObjCClass(theDecl, NotForDefinition); |
| |
| return IGM.getAddrOfTypeMetadata(type, false); |
| } |
| |
| /// Attempts to return a constant type metadata reference for a |
| /// nominal type. |
| ConstantReference |
| irgen::tryEmitConstantTypeMetadataRef(IRGenModule &IGM, CanType type, |
| SymbolReferenceKind refKind) { |
| if (!isTypeMetadataAccessTrivial(IGM, type)) |
| return ConstantReference(); |
| |
| return IGM.getAddrOfTypeMetadata(type, false, refKind); |
| } |
| |
| /// Emit a reference to an ObjC class. In general, the only things |
| /// you're allowed to do with the address of an ObjC class symbol are |
| /// (1) send ObjC messages to it (in which case the message will be |
| /// forwarded to the real class, if one exists) or (2) put it in |
| /// various data sections where the ObjC runtime will properly arrange |
| /// things. Therefore, we must typically force the initialization of |
| /// a class when emitting a reference to it. |
| llvm::Value *irgen::emitObjCHeapMetadataRef(IRGenFunction &IGF, |
| ClassDecl *theClass, |
| bool allowUninitialized) { |
| // If the class is visible only through the Objective-C runtime, form the |
| // appropriate runtime call. |
| if (theClass->getForeignClassKind() == ClassDecl::ForeignKind::RuntimeOnly) { |
| SmallString<64> scratch; |
| auto className = |
| IGF.IGM.getAddrOfGlobalString(theClass->getObjCRuntimeName(scratch)); |
| return IGF.Builder.CreateCall(IGF.IGM.getLookUpClassFn(), className); |
| } |
| |
| assert(!theClass->isForeign()); |
| |
| Address classRef = IGF.IGM.getAddrOfObjCClassRef(theClass); |
| auto classObject = IGF.Builder.CreateLoad(classRef); |
| if (allowUninitialized) return classObject; |
| |
| // TODO: memoize this the same way that we memoize Swift type metadata? |
| return IGF.Builder.CreateCall(IGF.IGM.getGetInitializedObjCClassFn(), |
| classObject); |
| } |
| |
| /// Emit a reference to the type metadata for a foreign type. |
| static llvm::Value *emitForeignTypeMetadataRef(IRGenFunction &IGF, |
| CanType type) { |
| llvm::Value *candidate = IGF.IGM.getAddrOfForeignTypeMetadataCandidate(type); |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetForeignTypeMetadataFn(), |
| candidate); |
| call->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::NoUnwind); |
| call->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadNone); |
| return call; |
| } |
| |
| /// Returns a metadata reference for a nominal type. |
| /// |
| /// This is only valid in a couple of special cases: |
| /// 1) The nominal type is generic, in which case we emit a call to the |
| /// generic metadata accessor function, which must be defined separately. |
| /// 2) The nominal type is a value type with a fixed size from this |
| /// resilience domain, in which case we can reference the constant |
| /// metadata directly. |
| /// |
| /// In any other case, a metadata accessor should be called instead. |
| static llvm::Value *emitNominalMetadataRef(IRGenFunction &IGF, |
| NominalTypeDecl *theDecl, |
| CanType theType) { |
| assert(!isa<ProtocolDecl>(theDecl)); |
| |
| if (!theDecl->isGenericContext()) { |
| assert(!IGF.IGM.isResilient(theDecl, ResilienceExpansion::Maximal)); |
| // TODO: If Obj-C interop is off, we can relax this to allow referencing |
| // class metadata too. |
| assert(isa<StructDecl>(theDecl) || isa<EnumDecl>(theDecl)); |
| return IGF.IGM.getAddrOfTypeMetadata(theType, false); |
| } |
| |
| // We are applying generic parameters to a generic type. |
| assert(theType->isSpecialized() && |
| theType->getAnyNominal() == theDecl); |
| |
| // Check to see if we've maybe got a local reference already. |
| if (auto cache = IGF.tryGetLocalTypeData(theType, |
| LocalTypeDataKind::forTypeMetadata())) |
| return cache; |
| |
| // Grab the substitutions. |
| GenericArguments genericArgs; |
| genericArgs.collect(IGF, theType); |
| assert((genericArgs.Values.size() > 0 || |
| theDecl->getGenericSignature()->areAllParamsConcrete()) |
| && "no generic args?!"); |
| |
| // Call the generic metadata accessor function. |
| llvm::Function *accessor = |
| IGF.IGM.getAddrOfGenericTypeMetadataAccessFunction(theDecl, |
| genericArgs.Types, |
| NotForDefinition); |
| |
| auto result = IGF.Builder.CreateCall(accessor, genericArgs.Values); |
| result->setDoesNotThrow(); |
| result->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadNone); |
| |
| IGF.setScopedLocalTypeData(theType, LocalTypeDataKind::forTypeMetadata(), |
| result); |
| return result; |
| } |
| |
| |
| bool irgen::hasKnownSwiftMetadata(IRGenModule &IGM, CanType type) { |
| if (ClassDecl *theClass = type.getClassOrBoundGenericClass()) { |
| return hasKnownSwiftMetadata(IGM, theClass); |
| } |
| |
| if (auto archetype = dyn_cast<ArchetypeType>(type)) { |
| if (auto superclass = archetype->getSuperclass()) { |
| return hasKnownSwiftMetadata(IGM, superclass->getCanonicalType()); |
| } |
| } |
| |
| // Class existentials, etc. |
| return false; |
| } |
| |
| /// Is the given class known to have Swift-compatible metadata? |
| bool irgen::hasKnownSwiftMetadata(IRGenModule &IGM, ClassDecl *theClass) { |
| // For now, the fact that a declaration was not implemented in Swift |
| // is enough to conclusively force us into a slower path. |
| // Eventually we might have an attribute here or something based on |
| // the deployment target. |
| return theClass->hasKnownSwiftImplementation(); |
| } |
| |
| /// Is it basically trivial to access the given metadata? If so, we don't |
| /// need a cache variable in its accessor. |
| bool irgen::isTypeMetadataAccessTrivial(IRGenModule &IGM, CanType type) { |
| assert(!type->hasArchetype()); |
| |
| // Value type metadata only requires dynamic initialization on first |
| // access if it contains a resilient type. |
| if (isa<StructType>(type) || isa<EnumType>(type)) { |
| auto nominalType = cast<NominalType>(type); |
| auto *nominalDecl = nominalType->getDecl(); |
| |
| // Imported type metadata always requires an accessor. |
| if (isa<ClangModuleUnit>(nominalDecl->getModuleScopeContext())) |
| return false; |
| |
| // Generic type metadata always requires an accessor. |
| if (nominalDecl->isGenericContext()) |
| return false; |
| |
| // Resiliently-sized metadata access always requires an accessor. |
| return (IGM.getTypeInfoForUnlowered(type).isFixedSize()); |
| } |
| |
| // The empty tuple type has a singleton metadata. |
| if (auto tuple = dyn_cast<TupleType>(type)) |
| return tuple->getNumElements() == 0; |
| |
| // The builtin types generally don't require metadata, but some of them |
| // have nodes in the runtime anyway. |
| if (isa<BuiltinType>(type)) |
| return true; |
| |
| // SIL box types are artificial, but for the purposes of dynamic layout, |
| // we use the NativeObject metadata. |
| if (isa<SILBoxType>(type)) |
| return true; |
| |
| // DynamicSelfType is actually local. |
| if (type->hasDynamicSelfType()) |
| return true; |
| |
| return false; |
| } |
| |
| static bool hasRequiredTypeMetadataAccessFunction(NominalTypeDecl *typeDecl) { |
| // This needs to be kept in sync with getTypeMetadataStrategy. |
| |
| if (isa<ProtocolDecl>(typeDecl)) |
| return false; |
| |
| switch (getDeclLinkage(typeDecl)) { |
| case FormalLinkage::PublicUnique: |
| case FormalLinkage::HiddenUnique: |
| case FormalLinkage::Private: |
| return true; |
| |
| case FormalLinkage::PublicNonUnique: |
| case FormalLinkage::HiddenNonUnique: |
| return false; |
| } |
| llvm_unreachable("bad formal linkage"); |
| |
| } |
| |
| /// Return the standard access strategy for getting a non-dependent |
| /// type metadata object. |
| MetadataAccessStrategy irgen::getTypeMetadataAccessStrategy(CanType type) { |
| // We should not be emitting accessors for partially-substituted |
| // generic types. |
| assert(!type->hasArchetype()); |
| |
| // Non-generic structs, enums, and classes are special cases. |
| // |
| // Note that while protocol types don't have a metadata pattern, |
| // we still require an accessor since we actually want to get |
| // the metadata for the existential type. |
| // |
| // This needs to kept in sync with hasRequiredTypeMetadataAccessPattern. |
| auto nominal = type->getAnyNominal(); |
| if (nominal && !isa<ProtocolDecl>(nominal)) { |
| // Metadata accessors for fully-substituted generic types are |
| // emitted with shared linkage. |
| if (nominal->isGenericContext() && !nominal->isObjC()) { |
| if (type->isSpecialized()) |
| return MetadataAccessStrategy::NonUniqueAccessor; |
| assert(type->hasUnboundGenericType()); |
| } |
| |
| // If the type doesn't guarantee that it has an access function, |
| // we might have to use a non-unique accessor. |
| |
| // Everything else requires accessors. |
| switch (getDeclLinkage(nominal)) { |
| case FormalLinkage::PublicUnique: |
| return MetadataAccessStrategy::PublicUniqueAccessor; |
| case FormalLinkage::HiddenUnique: |
| return MetadataAccessStrategy::HiddenUniqueAccessor; |
| case FormalLinkage::Private: |
| return MetadataAccessStrategy::PrivateAccessor; |
| |
| case FormalLinkage::PublicNonUnique: |
| case FormalLinkage::HiddenNonUnique: |
| return MetadataAccessStrategy::NonUniqueAccessor; |
| } |
| llvm_unreachable("bad formal linkage"); |
| } |
| |
| // Everything else requires a shared accessor function. |
| return MetadataAccessStrategy::NonUniqueAccessor; |
| } |
| |
| /// Emit a string encoding the labels in the given tuple type. |
| static llvm::Constant *getTupleLabelsString(IRGenModule &IGM, |
| CanTupleType type) { |
| bool hasLabels = false; |
| llvm::SmallString<128> buffer; |
| for (auto &elt : type->getElements()) { |
| if (elt.hasName()) { |
| hasLabels = true; |
| buffer.append(elt.getName().str()); |
| } |
| |
| // Each label is space-terminated. |
| buffer += ' '; |
| } |
| |
| // If there are no labels, use a null pointer. |
| if (!hasLabels) { |
| return llvm::ConstantPointerNull::get(IGM.Int8PtrTy); |
| } |
| |
| // Otherwise, create a new string literal. |
| // This method implicitly adds a null terminator. |
| return IGM.getAddrOfGlobalString(buffer); |
| } |
| |
| namespace { |
| /// A visitor class for emitting a reference to a metatype object. |
| /// This implements a "raw" access, useful for implementing cache |
| /// functions or for implementing dependent accesses. |
| /// |
| /// If the access requires runtime initialization, that initialization |
| /// must be dependency-ordered-before any load that carries a dependency |
| /// from the resulting metadata pointer. |
| class EmitTypeMetadataRef |
| : public CanTypeVisitor<EmitTypeMetadataRef, llvm::Value *> { |
| private: |
| IRGenFunction &IGF; |
| public: |
| EmitTypeMetadataRef(IRGenFunction &IGF) : IGF(IGF) {} |
| |
| #define TREAT_AS_OPAQUE(KIND) \ |
| llvm::Value *visit##KIND##Type(KIND##Type *type) { \ |
| return visitOpaqueType(CanType(type)); \ |
| } |
| TREAT_AS_OPAQUE(BuiltinInteger) |
| TREAT_AS_OPAQUE(BuiltinFloat) |
| TREAT_AS_OPAQUE(BuiltinVector) |
| TREAT_AS_OPAQUE(BuiltinRawPointer) |
| #undef TREAT_AS_OPAQUE |
| |
| llvm::Value *emitDirectMetadataRef(CanType type) { |
| return IGF.IGM.getAddrOfTypeMetadata(type, |
| /*pattern*/ false); |
| } |
| |
| /// The given type should use opaque type info. We assume that |
| /// the runtime always provides an entry for such a type; right |
| /// now, that mapping is as one of the power-of-two integer types. |
| llvm::Value *visitOpaqueType(CanType type) { |
| auto &opaqueTI = cast<FixedTypeInfo>(IGF.IGM.getTypeInfoForLowered(type)); |
| unsigned numBits = opaqueTI.getFixedSize().getValueInBits(); |
| if (!llvm::isPowerOf2_32(numBits)) |
| numBits = llvm::NextPowerOf2(numBits); |
| auto intTy = BuiltinIntegerType::get(numBits, IGF.IGM.Context); |
| return emitDirectMetadataRef(CanType(intTy)); |
| } |
| |
| llvm::Value *visitBuiltinNativeObjectType(CanBuiltinNativeObjectType type) { |
| return emitDirectMetadataRef(type); |
| } |
| |
| llvm::Value *visitBuiltinBridgeObjectType(CanBuiltinBridgeObjectType type) { |
| return emitDirectMetadataRef(type); |
| } |
| |
| llvm::Value *visitBuiltinUnknownObjectType(CanBuiltinUnknownObjectType type) { |
| return emitDirectMetadataRef(type); |
| } |
| |
| llvm::Value *visitBuiltinUnsafeValueBufferType( |
| CanBuiltinUnsafeValueBufferType type) { |
| return emitDirectMetadataRef(type); |
| } |
| |
| llvm::Value *visitNominalType(CanNominalType type) { |
| assert(!type->isExistentialType()); |
| return emitNominalMetadataRef(IGF, type->getDecl(), type); |
| } |
| |
| llvm::Value *visitBoundGenericType(CanBoundGenericType type) { |
| assert(!type->isExistentialType()); |
| return emitNominalMetadataRef(IGF, type->getDecl(), type); |
| } |
| |
| llvm::Value *visitTupleType(CanTupleType type) { |
| if (auto cached = tryGetLocal(type)) |
| return cached; |
| |
| // I think the sanest thing to do here is drop labels, but maybe |
| // that's not correct. If so, that's really unfortunate in a |
| // lot of ways. |
| |
| // Er, varargs bit? Should that go in? |
| |
| |
| switch (type->getNumElements()) { |
| case 0: {// Special case the empty tuple, just use the global descriptor. |
| llvm::Constant *fullMetadata = IGF.IGM.getEmptyTupleMetadata(); |
| llvm::Constant *indices[] = { |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0), |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 1) |
| }; |
| return llvm::ConstantExpr::getInBoundsGetElementPtr( |
| /*Ty=*/nullptr, fullMetadata, indices); |
| } |
| |
| case 1: |
| // For metadata purposes, we consider a singleton tuple to be |
| // isomorphic to its element type. |
| return IGF.emitTypeMetadataRef(type.getElementType(0)); |
| |
| case 2: { |
| // Find the metadata pointer for this element. |
| auto elt0Metadata = IGF.emitTypeMetadataRef(type.getElementType(0)); |
| auto elt1Metadata = IGF.emitTypeMetadataRef(type.getElementType(1)); |
| |
| llvm::Value *args[] = { |
| elt0Metadata, elt1Metadata, |
| getTupleLabelsString(IGF.IGM, type), |
| llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed |
| }; |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadata2Fn(), |
| args); |
| call->setDoesNotThrow(); |
| return setLocal(CanType(type), call); |
| } |
| |
| case 3: { |
| // Find the metadata pointer for this element. |
| auto elt0Metadata = IGF.emitTypeMetadataRef(type.getElementType(0)); |
| auto elt1Metadata = IGF.emitTypeMetadataRef(type.getElementType(1)); |
| auto elt2Metadata = IGF.emitTypeMetadataRef(type.getElementType(2)); |
| |
| llvm::Value *args[] = { |
| elt0Metadata, elt1Metadata, elt2Metadata, |
| getTupleLabelsString(IGF.IGM, type), |
| llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed |
| }; |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadata3Fn(), |
| args); |
| call->setDoesNotThrow(); |
| return setLocal(CanType(type), call); |
| } |
| default: |
| // TODO: use a caching entrypoint (with all information |
| // out-of-line) for non-dependent tuples. |
| |
| llvm::Value *pointerToFirst = nullptr; // appease -Wuninitialized |
| |
| auto elements = type.getElementTypes(); |
| auto arrayTy = llvm::ArrayType::get(IGF.IGM.TypeMetadataPtrTy, |
| elements.size()); |
| Address buffer = IGF.createAlloca(arrayTy,IGF.IGM.getPointerAlignment(), |
| "tuple-elements"); |
| IGF.Builder.CreateLifetimeStart(buffer, |
| IGF.IGM.getPointerSize() * elements.size()); |
| for (unsigned i = 0, e = elements.size(); i != e; ++i) { |
| // Find the metadata pointer for this element. |
| llvm::Value *eltMetadata = IGF.emitTypeMetadataRef(elements[i]); |
| |
| // GEP to the appropriate element and store. |
| Address eltPtr = IGF.Builder.CreateStructGEP(buffer, i, |
| IGF.IGM.getPointerSize()); |
| IGF.Builder.CreateStore(eltMetadata, eltPtr); |
| |
| // Remember the GEP to the first element. |
| if (i == 0) pointerToFirst = eltPtr.getAddress(); |
| } |
| |
| llvm::Value *args[] = { |
| llvm::ConstantInt::get(IGF.IGM.SizeTy, elements.size()), |
| pointerToFirst, |
| getTupleLabelsString(IGF.IGM, type), |
| llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed |
| }; |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadataFn(), |
| args); |
| call->setDoesNotThrow(); |
| |
| IGF.Builder.CreateLifetimeEnd(buffer, |
| IGF.IGM.getPointerSize() * elements.size()); |
| |
| return setLocal(type, call); |
| } |
| } |
| |
| llvm::Value *visitGenericFunctionType(CanGenericFunctionType type) { |
| IGF.unimplemented(SourceLoc(), |
| "metadata ref for generic function type"); |
| return llvm::UndefValue::get(IGF.IGM.TypeMetadataPtrTy); |
| } |
| |
| llvm::Value *getFunctionParameterRef(AnyFunctionType::CanParam param) { |
| auto type = param.getType(); |
| if (param.getParameterFlags().isInOut()) |
| type = type->getInOutObjectType()->getCanonicalType(); |
| return IGF.emitTypeMetadataRef(type); |
| } |
| |
| llvm::Value *visitFunctionType(CanFunctionType type) { |
| if (auto metatype = tryGetLocal(type)) |
| return metatype; |
| |
| auto result = |
| IGF.emitTypeMetadataRef(type->getResult()->getCanonicalType()); |
| |
| auto params = type.getParams(); |
| auto numParams = params.size(); |
| |
| bool hasFlags = false; |
| for (auto param : params) { |
| if (!param.getParameterFlags().isNone()) { |
| hasFlags = true; |
| break; |
| } |
| } |
| |
| // Map the convention to a runtime metadata value. |
| FunctionMetadataConvention metadataConvention; |
| switch (type->getRepresentation()) { |
| case FunctionTypeRepresentation::Swift: |
| metadataConvention = FunctionMetadataConvention::Swift; |
| break; |
| case FunctionTypeRepresentation::Thin: |
| metadataConvention = FunctionMetadataConvention::Thin; |
| break; |
| case FunctionTypeRepresentation::Block: |
| metadataConvention = FunctionMetadataConvention::Block; |
| break; |
| case FunctionTypeRepresentation::CFunctionPointer: |
| metadataConvention = FunctionMetadataConvention::CFunctionPointer; |
| break; |
| } |
| |
| auto flagsVal = FunctionTypeFlags() |
| .withNumParameters(numParams) |
| .withConvention(metadataConvention) |
| .withThrows(type->throws()) |
| .withParameterFlags(hasFlags); |
| |
| auto flags = llvm::ConstantInt::get(IGF.IGM.SizeTy, |
| flagsVal.getIntValue()); |
| |
| auto collectParameters = |
| [&](llvm::function_ref<void(unsigned, llvm::Value *, |
| ParameterFlags flags)> |
| processor) { |
| for (auto index : indices(params)) { |
| auto param = params[index]; |
| auto flags = param.getParameterFlags(); |
| |
| auto parameterFlags = ParameterFlags() |
| .withInOut(flags.isInOut()) |
| .withShared(flags.isShared()) |
| .withVariadic(flags.isVariadic()); |
| |
| processor(index, getFunctionParameterRef(param), parameterFlags); |
| } |
| }; |
| |
| auto constructSimpleCall = |
| [&](llvm::SmallVectorImpl<llvm::Value *> &arguments) |
| -> llvm::Constant * { |
| arguments.push_back(flags); |
| |
| collectParameters([&](unsigned i, llvm::Value *typeRef, |
| ParameterFlags flags) { |
| arguments.push_back(typeRef); |
| if (hasFlags) |
| arguments.push_back( |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, flags.getIntValue())); |
| }); |
| |
| arguments.push_back(result); |
| |
| switch (params.size()) { |
| case 1: |
| return hasFlags ? IGF.IGM.getGetFunctionMetadata1WithFlagsFn() |
| : IGF.IGM.getGetFunctionMetadata1Fn(); |
| |
| case 2: |
| return hasFlags ? IGF.IGM.getGetFunctionMetadata2WithFlagsFn() |
| : IGF.IGM.getGetFunctionMetadata2Fn(); |
| |
| case 3: |
| return hasFlags ? IGF.IGM.getGetFunctionMetadata3WithFlagsFn() |
| : IGF.IGM.getGetFunctionMetadata3Fn(); |
| |
| default: |
| llvm_unreachable("supports only 1/2/3 parameter functions"); |
| } |
| }; |
| |
| auto getArrayFor = [&](llvm::Type *elementType, unsigned size, |
| const llvm::Twine &name) -> Address { |
| auto arrayTy = llvm::ArrayType::get(elementType, size); |
| return IGF.createAlloca(arrayTy, IGF.IGM.getPointerAlignment(), name); |
| }; |
| |
| switch (numParams) { |
| case 1: |
| case 2: |
| case 3: { |
| llvm::SmallVector<llvm::Value *, 8> arguments; |
| auto *metadataFn = constructSimpleCall(arguments); |
| auto *call = IGF.Builder.CreateCall(metadataFn, arguments); |
| call->setDoesNotThrow(); |
| return setLocal(CanType(type), call); |
| } |
| |
| default: |
| auto *const Int32Ptr = IGF.IGM.Int32Ty->getPointerTo(); |
| |
| llvm::SmallVector<llvm::Value *, 8> arguments; |
| arguments.push_back(flags); |
| |
| Address parameters; |
| if (!params.empty()) { |
| parameters = getArrayFor(IGF.IGM.TypeMetadataPtrTy, numParams, |
| "function-parameters"); |
| |
| IGF.Builder.CreateLifetimeStart(parameters, |
| IGF.IGM.getPointerSize() * numParams); |
| |
| ConstantInitBuilder paramFlags(IGF.IGM); |
| auto flagsArr = paramFlags.beginArray(); |
| collectParameters([&](unsigned i, llvm::Value *typeRef, |
| ParameterFlags flags) { |
| auto argPtr = IGF.Builder.CreateStructGEP(parameters, i, |
| IGF.IGM.getPointerSize()); |
| IGF.Builder.CreateStore(typeRef, argPtr); |
| if (hasFlags) |
| flagsArr.addInt32(flags.getIntValue()); |
| }); |
| |
| auto parametersPtr = |
| IGF.Builder.CreateStructGEP(parameters, 0, Size(0)); |
| arguments.push_back(parametersPtr.getAddress()); |
| |
| if (hasFlags) { |
| auto *flagsVar = flagsArr.finishAndCreateGlobal( |
| "parameter-flags", IGF.IGM.getPointerAlignment(), |
| /* constant */ true); |
| arguments.push_back(IGF.Builder.CreateBitCast(flagsVar, Int32Ptr)); |
| } else { |
| flagsArr.abandon(); |
| arguments.push_back(llvm::ConstantPointerNull::get(Int32Ptr)); |
| } |
| } else { |
| arguments.push_back(llvm::ConstantPointerNull::get( |
| IGF.IGM.TypeMetadataPtrTy->getPointerTo())); |
| arguments.push_back(llvm::ConstantPointerNull::get(Int32Ptr)); |
| } |
| |
| arguments.push_back(result); |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetFunctionMetadataFn(), |
| arguments); |
| call->setDoesNotThrow(); |
| |
| if (parameters.isValid()) |
| IGF.Builder.CreateLifetimeEnd(parameters, |
| IGF.IGM.getPointerSize() * numParams); |
| |
| return setLocal(type, call); |
| } |
| } |
| |
| llvm::Value *visitAnyMetatypeType(CanAnyMetatypeType type) { |
| // FIXME: We shouldn't accept a lowered metatype here, but we need to |
| // represent Optional<@objc_metatype T.Type> as an AST type for ABI |
| // reasons. |
| |
| // assert(!type->hasRepresentation() |
| // && "should not be asking for a representation-specific metatype " |
| // "metadata"); |
| |
| if (auto metatype = tryGetLocal(type)) |
| return metatype; |
| |
| auto instMetadata = IGF.emitTypeMetadataRef(type.getInstanceType()); |
| auto fn = isa<MetatypeType>(type) |
| ? IGF.IGM.getGetMetatypeMetadataFn() |
| : IGF.IGM.getGetExistentialMetatypeMetadataFn(); |
| auto call = IGF.Builder.CreateCall(fn, instMetadata); |
| call->setDoesNotThrow(); |
| |
| return setLocal(type, call); |
| } |
| |
| llvm::Value *visitModuleType(CanModuleType type) { |
| IGF.unimplemented(SourceLoc(), "metadata ref for module type"); |
| return llvm::UndefValue::get(IGF.IGM.TypeMetadataPtrTy); |
| } |
| |
| llvm::Value *visitDynamicSelfType(CanDynamicSelfType type) { |
| return IGF.getLocalSelfMetadata(); |
| } |
| |
| llvm::Value *emitExistentialTypeMetadata(CanType type) { |
| if (auto metatype = tryGetLocal(type)) |
| return metatype; |
| |
| auto layout = type.getExistentialLayout(); |
| |
| auto protocols = layout.getProtocols(); |
| |
| // Collect references to the protocol descriptors. |
| auto descriptorArrayTy |
| = llvm::ArrayType::get(IGF.IGM.ProtocolDescriptorPtrTy, |
| protocols.size()); |
| Address descriptorArray = IGF.createAlloca(descriptorArrayTy, |
| IGF.IGM.getPointerAlignment(), |
| "protocols"); |
| IGF.Builder.CreateLifetimeStart(descriptorArray, |
| IGF.IGM.getPointerSize() * protocols.size()); |
| descriptorArray = IGF.Builder.CreateBitCast(descriptorArray, |
| IGF.IGM.ProtocolDescriptorPtrTy->getPointerTo()); |
| |
| unsigned index = 0; |
| for (auto *protoTy : protocols) { |
| auto *protoDecl = protoTy->getDecl(); |
| llvm::Value *ref = emitProtocolDescriptorRef(IGF, protoDecl); |
| Address slot = IGF.Builder.CreateConstArrayGEP(descriptorArray, |
| index, IGF.IGM.getPointerSize()); |
| IGF.Builder.CreateStore(ref, slot); |
| ++index; |
| } |
| |
| // Note: ProtocolClassConstraint::Class is 0, ::Any is 1. |
| auto classConstraint = |
| llvm::ConstantInt::get(IGF.IGM.Int1Ty, |
| !layout.requiresClass()); |
| llvm::Value *superclassConstraint = |
| llvm::ConstantPointerNull::get(IGF.IGM.TypeMetadataPtrTy); |
| if (layout.superclass) { |
| superclassConstraint = IGF.emitTypeMetadataRef( |
| CanType(layout.superclass)); |
| } |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetExistentialMetadataFn(), |
| {classConstraint, |
| superclassConstraint, |
| IGF.IGM.getSize(Size(protocols.size())), |
| descriptorArray.getAddress()}); |
| call->setDoesNotThrow(); |
| IGF.Builder.CreateLifetimeEnd(descriptorArray, |
| IGF.IGM.getPointerSize() * protocols.size()); |
| return setLocal(type, call); |
| } |
| |
| llvm::Value *visitProtocolType(CanProtocolType type) { |
| return emitExistentialTypeMetadata(type); |
| } |
| |
| llvm::Value *visitProtocolCompositionType(CanProtocolCompositionType type) { |
| return emitExistentialTypeMetadata(type); |
| } |
| |
| llvm::Value *visitReferenceStorageType(CanReferenceStorageType type) { |
| llvm_unreachable("reference storage type should have been converted by " |
| "SILGen"); |
| } |
| llvm::Value *visitSILFunctionType(CanSILFunctionType type) { |
| llvm_unreachable("should not be asking for metadata of a lowered SIL " |
| "function type--SILGen should have used the AST type"); |
| } |
| llvm::Value *visitSILTokenType(CanSILTokenType type) { |
| llvm_unreachable("should not be asking for metadata of a SILToken type"); |
| } |
| |
| llvm::Value *visitArchetypeType(CanArchetypeType type) { |
| return emitArchetypeTypeMetadataRef(IGF, type); |
| } |
| |
| llvm::Value *visitGenericTypeParamType(CanGenericTypeParamType type) { |
| llvm_unreachable("dependent type should have been substituted by Sema or SILGen"); |
| } |
| |
| llvm::Value *visitDependentMemberType(CanDependentMemberType type) { |
| llvm_unreachable("dependent type should have been substituted by Sema or SILGen"); |
| } |
| |
| llvm::Value *visitLValueType(CanLValueType type) { |
| llvm_unreachable("lvalue type should have been lowered by SILGen"); |
| } |
| llvm::Value *visitInOutType(CanInOutType type) { |
| llvm_unreachable("inout type should have been lowered by SILGen"); |
| } |
| llvm::Value *visitErrorType(CanErrorType type) { |
| llvm_unreachable("error type should not appear in IRGen"); |
| } |
| |
| llvm::Value *visitSILBlockStorageType(CanSILBlockStorageType type) { |
| llvm_unreachable("cannot ask for metadata of block storage"); |
| } |
| |
| llvm::Value *visitSILBoxType(CanSILBoxType type) { |
| // The Builtin.NativeObject metadata can stand in for boxes. |
| return emitDirectMetadataRef(type->getASTContext().TheNativeObjectType); |
| } |
| |
| /// Try to find the metatype in local data. |
| llvm::Value *tryGetLocal(CanType type) { |
| return IGF.tryGetLocalTypeData(type, LocalTypeDataKind::forTypeMetadata()); |
| } |
| |
| /// Set the metatype in local data. |
| llvm::Value *setLocal(CanType type, llvm::Instruction *metatype) { |
| IGF.setScopedLocalTypeData(type, LocalTypeDataKind::forTypeMetadata(), |
| metatype); |
| return metatype; |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// Emit a type metadata reference without using an accessor function. |
| static llvm::Value *emitDirectTypeMetadataRef(IRGenFunction &IGF, |
| CanType type) { |
| return EmitTypeMetadataRef(IGF).visit(type); |
| } |
| |
| static Address emitAddressOfSuperclassRefInClassMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata) { |
| // The superclass field in a class type is the first field past the isa. |
| unsigned index = 1; |
| |
| Address addr(metadata, IGF.IGM.getPointerAlignment()); |
| addr = IGF.Builder.CreateBitCast(addr, |
| IGF.IGM.TypeMetadataPtrTy->getPointerTo()); |
| return IGF.Builder.CreateConstArrayGEP(addr, index, IGF.IGM.getPointerSize()); |
| } |
| |
| static bool isLoadFrom(llvm::Value *value, Address address) { |
| if (auto load = dyn_cast<llvm::LoadInst>(value)) { |
| return load->getOperand(0) == address.getAddress(); |
| } |
| return false; |
| } |
| |
| /// Emit the body of a lazy cache accessor. |
| /// |
| /// If cacheVariable is null, we perform the direct access every time. |
| /// This is used for metadata accessors that come about due to resilience, |
| /// where the direct access is completely trivial. |
| void irgen::emitLazyCacheAccessFunction(IRGenModule &IGM, |
| llvm::Function *accessor, |
| llvm::GlobalVariable *cacheVariable, |
| const llvm::function_ref<llvm::Value*(IRGenFunction &IGF)> &getValue) { |
| accessor->setDoesNotThrow(); |
| |
| // This function is logically 'readnone': the caller does not need |
| // to reason about any side effects or stores it might perform. |
| accessor->setDoesNotAccessMemory(); |
| |
| IRGenFunction IGF(IGM, accessor); |
| if (IGM.DebugInfo) |
| IGM.DebugInfo->emitArtificialFunction(IGF, accessor); |
| |
| // If there's no cache variable, just perform the direct access. |
| if (cacheVariable == nullptr) { |
| IGF.Builder.CreateRet(getValue(IGF)); |
| return; |
| } |
| |
| // Set up the cache variable. |
| llvm::Constant *null = |
| llvm::ConstantPointerNull::get( |
| cast<llvm::PointerType>(cacheVariable->getValueType())); |
| |
| cacheVariable->setInitializer(null); |
| cacheVariable->setAlignment(IGM.getPointerAlignment().getValue()); |
| Address cache(cacheVariable, IGM.getPointerAlignment()); |
| |
| // Okay, first thing, check the cache variable. |
| // |
| // Conceptually, this needs to establish memory ordering with the |
| // store we do later in the function: if the metadata value is |
| // non-null, we must be able to see any stores performed by the |
| // initialization of the metadata. However, any attempt to read |
| // from the metadata will be address-dependent on the loaded |
| // metadata pointer, which is sufficient to provide adequate |
| // memory ordering guarantees on all the platforms we care about: |
| // ARM has special rules about address dependencies, and x86's |
| // memory ordering is strong enough to guarantee the visibility |
| // even without the address dependency. |
| // |
| // And we do not need to worry about the compiler because the |
| // address dependency naturally forces an order to the memory |
| // accesses. |
| // |
| // Therefore, we can perform a completely naked load here. |
| // FIXME: Technically should be "consume", but that introduces barriers in the |
| // current LLVM ARM backend. |
| auto load = IGF.Builder.CreateLoad(cache); |
| // Make this barrier explicit when building for TSan to avoid false positives. |
| if (IGM.IRGen.Opts.Sanitizers & SanitizerKind::Thread) |
| load->setOrdering(llvm::AtomicOrdering::Acquire); |
| |
| |
| // Compare the load result against null. |
| auto isNullBB = IGF.createBasicBlock("cacheIsNull"); |
| auto contBB = IGF.createBasicBlock("cont"); |
| llvm::Value *comparison = IGF.Builder.CreateICmpEQ(load, null); |
| IGF.Builder.CreateCondBr(comparison, isNullBB, contBB); |
| auto loadBB = IGF.Builder.GetInsertBlock(); |
| |
| // If the load yielded null, emit the type metadata. |
| IGF.Builder.emitBlock(isNullBB); |
| llvm::Value *directResult = getValue(IGF); |
| |
| // Store it back to the cache variable. This needs to be a store-release |
| // because it needs to propagate memory visibility to the other threads |
| // that can access the cache: the initializing stores might be visible |
| // to this thread, but they aren't transitively guaranteed to be visible |
| // to other threads unless this is a store-release. |
| // |
| // However, we can skip this if the value was actually loaded from the |
| // cache. This is a simple, if hacky, peephole that's useful for the |
| // code in emitInPlaceTypeMetadataAccessFunctionBody. |
| if (!isLoadFrom(directResult, cache)) { |
| IGF.Builder.CreateStore(directResult, cache) |
| ->setAtomic(llvm::AtomicOrdering::Release); |
| } |
| |
| IGF.Builder.CreateBr(contBB); |
| auto storeBB = IGF.Builder.GetInsertBlock(); |
| |
| // Emit the continuation block. |
| IGF.Builder.emitBlock(contBB); |
| auto phi = IGF.Builder.CreatePHI(null->getType(), 2); |
| phi->addIncoming(load, loadBB); |
| phi->addIncoming(directResult, storeBB); |
| |
| IGF.Builder.CreateRet(phi); |
| } |
| |
| static llvm::Value *emitGenericMetadataAccessFunction(IRGenFunction &IGF, |
| NominalTypeDecl *nominal, |
| GenericArguments &genericArgs) { |
| CanType declaredType = nominal->getDeclaredType()->getCanonicalType(); |
| llvm::Value *metadata = IGF.IGM.getAddrOfTypeMetadata(declaredType, true); |
| |
| // Collect input arguments to the generic metadata accessor, as laid out |
| // by the GenericArguments class. |
| for (auto &arg : IGF.CurFn->args()) |
| genericArgs.Values.push_back(&arg); |
| assert(genericArgs.Values.size() == genericArgs.Types.size()); |
| assert((genericArgs.Values.size() > 0 || |
| nominal->getGenericSignature()->areAllParamsConcrete()) |
| && "no generic args?!"); |
| |
| // Slam that information directly into the generic arguments buffer. |
| auto argsBufferTy = |
| llvm::StructType::get(IGF.IGM.LLVMContext, genericArgs.Types); |
| Address argsBuffer = IGF.createAlloca(argsBufferTy, |
| IGF.IGM.getPointerAlignment(), |
| "generic.arguments"); |
| IGF.Builder.CreateLifetimeStart(argsBuffer, |
| IGF.IGM.getPointerSize() * genericArgs.Values.size()); |
| for (unsigned i = 0, e = genericArgs.Values.size(); i != e; ++i) { |
| Address elt = IGF.Builder.CreateStructGEP(argsBuffer, i, |
| IGF.IGM.getPointerSize() * i); |
| IGF.Builder.CreateStore(genericArgs.Values[i], elt); |
| } |
| |
| // Cast to void*. |
| llvm::Value *arguments = |
| IGF.Builder.CreateBitCast(argsBuffer.getAddress(), IGF.IGM.Int8PtrTy); |
| |
| // Make the call. |
| auto result = IGF.Builder.CreateCall(IGF.IGM.getGetGenericMetadataFn(), |
| {metadata, arguments}); |
| result->setDoesNotThrow(); |
| result->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadOnly); |
| |
| IGF.Builder.CreateLifetimeEnd(argsBuffer, |
| IGF.IGM.getPointerSize() * genericArgs.Values.size()); |
| |
| return result; |
| |
| } |
| |
| using InPlaceMetadataInitializer = |
| llvm::function_ref<llvm::Value*(IRGenFunction &IGF, llvm::Value *metadata)>; |
| |
| /// Emit a helper function for swift_once that performs in-place |
| /// initialization of the given nominal type. |
| static llvm::Constant * |
| createInPlaceMetadataInitializationFunction(IRGenModule &IGM, |
| CanNominalType type, |
| llvm::Constant *metadata, |
| llvm::Constant *cacheVariable, |
| InPlaceMetadataInitializer &&initialize) { |
| // There's an ignored i8* parameter. |
| auto fnTy = llvm::FunctionType::get(IGM.VoidTy, {IGM.Int8PtrTy}, |
| /*variadic*/ false); |
| llvm::Function *fn = llvm::Function::Create(fnTy, |
| llvm::GlobalValue::PrivateLinkage, |
| Twine("initialize_metadata_") |
| + type->getDecl()->getName().str(), |
| &IGM.Module); |
| fn->setAttributes(IGM.constructInitialAttributes()); |
| |
| // Set up the function. |
| IRGenFunction IGF(IGM, fn); |
| if (IGM.DebugInfo) |
| IGM.DebugInfo->emitArtificialFunction(IGF, fn); |
| |
| // Skip instrumentation when building for TSan to avoid false positives. |
| // The synchronization for this happens in the Runtime and we do not see it. |
| if (IGM.IRGen.Opts.Sanitizers & SanitizerKind::Thread) |
| fn->removeFnAttr(llvm::Attribute::SanitizeThread); |
| |
| // Emit the initialization. |
| llvm::Value *relocatedMetadata = initialize(IGF, metadata); |
| |
| // Store back to the cache variable. |
| IGF.Builder.CreateStore(relocatedMetadata, |
| Address(cacheVariable, IGM.getPointerAlignment())) |
| ->setAtomic(llvm::AtomicOrdering::Release); |
| |
| IGF.Builder.CreateRetVoid(); |
| return fn; |
| } |
| |
| /// Emit the function body for the type metadata accessor of a nominal type |
| /// that might require in-place initialization. |
| static llvm::Value * |
| emitInPlaceTypeMetadataAccessFunctionBody(IRGenFunction &IGF, |
| CanNominalType type, |
| llvm::Constant *cacheVariable, |
| InPlaceMetadataInitializer &&initializer) { |
| llvm::Constant *metadata = IGF.IGM.getAddrOfTypeMetadata(type, false); |
| |
| // We might not have interesting initialization to do. |
| assert((cacheVariable == nullptr) == |
| isTypeMetadataAccessTrivial(IGF.IGM, type)); |
| if (!cacheVariable) |
| return metadata; |
| |
| // Okay, we have non-trivial initialization to do. |
| // Ensure that we don't have multiple threads racing to do this. |
| llvm::GlobalVariable *onceGuard = |
| new llvm::GlobalVariable(IGF.IGM.Module, IGF.IGM.OnceTy, /*constant*/ false, |
| llvm::GlobalValue::PrivateLinkage, |
| llvm::Constant::getNullValue(IGF.IGM.OnceTy), |
| Twine(IGF.CurFn->getName()) + ".once_token"); |
| |
| // There's no point in performing the fast-path token check here |
| // because we've already checked the cache variable. We're just using |
| // swift_once to guarantee thread safety. |
| assert(cacheVariable && "lazy initialization but no cache variable"); |
| |
| // Create the protected function. swift_once wants this as an i8*. |
| llvm::Value *onceFn = |
| createInPlaceMetadataInitializationFunction(IGF.IGM, type, metadata, |
| cacheVariable, |
| std::move(initializer)); |
| onceFn = IGF.Builder.CreateBitCast(onceFn, IGF.IGM.Int8PtrTy); |
| auto context = llvm::UndefValue::get(IGF.IGM.Int8PtrTy); |
| |
| auto onceCall = IGF.Builder.CreateCall(IGF.IGM.getOnceFn(), |
| {onceGuard, onceFn, context}); |
| onceCall->setCallingConv(IGF.IGM.DefaultCC); |
| |
| // We can just load the cache now. |
| // TODO: this should be consume-ordered when LLVM supports it. |
| Address cacheAddr = Address(cacheVariable, IGF.IGM.getPointerAlignment()); |
| llvm::LoadInst *relocatedMetadata = IGF.Builder.CreateLoad(cacheAddr); |
| // Make this barrier explicit when building for TSan to avoid false positives. |
| if (IGF.IGM.IRGen.Opts.Sanitizers & SanitizerKind::Thread) |
| relocatedMetadata->setOrdering(llvm::AtomicOrdering::Acquire); |
| |
| // emitLazyCacheAccessFunction will see that the value was loaded from |
| // the guard variable and skip the redundant store back. |
| return relocatedMetadata; |
| } |
| |
| /// Emit the body of a metadata accessor function for the given type. |
| /// |
| /// This function is appropriate for ordinary situations where the |
| /// construction of the metadata value just involves calling idempotent |
| /// metadata-construction functions. It is not used for the in-place |
| /// initialization of non-generic nominal type metadata. |
| static llvm::Value *emitTypeMetadataAccessFunctionBody(IRGenFunction &IGF, |
| CanType type) { |
| assert(!type->hasArchetype() && |
| "cannot emit metadata accessor for context-dependent type"); |
| |
| // We only take this path for non-generic nominal types. |
| auto typeDecl = type->getAnyNominal(); |
| if (!typeDecl) |
| return emitDirectTypeMetadataRef(IGF, type); |
| |
| if (typeDecl->isGenericContext() && |
| !(isa<ClassDecl>(typeDecl) && |
| isa<ClangModuleUnit>(typeDecl->getModuleScopeContext()))) { |
| // This is a metadata accessor for a fully substituted generic type. |
| return emitDirectTypeMetadataRef(IGF, type); |
| } |
| |
| // We should never be emitting a metadata accessor for resilient nominal |
| // types outside of their defining module. We'd only do that anyway for |
| // types that don't guarantee the existence of a non-unique access |
| // function, and that should never be true of a resilient type with |
| // external availability. |
| // |
| // (The type might still not have a statically-known layout. It just |
| // can't be resilient at the top level: we have to know its immediate |
| // members, or we can't even begin to approach the problem of emitting |
| // metadata for it.) |
| assert(!IGF.IGM.isResilient(typeDecl, ResilienceExpansion::Maximal)); |
| |
| // Non-native types are just wrapped in various ways. |
| if (auto classDecl = dyn_cast<ClassDecl>(typeDecl)) { |
| // We emit a completely different pattern for foreign classes. |
| if (classDecl->getForeignClassKind() == ClassDecl::ForeignKind::CFType) { |
| return emitForeignTypeMetadataRef(IGF, type); |
| } |
| |
| // Classes that might not have Swift metadata use a different |
| // symbol name. |
| if (!hasKnownSwiftMetadata(IGF.IGM, classDecl)) { |
| return emitObjCMetadataRef(IGF, classDecl); |
| } |
| |
| // Imported value types require foreign metadata uniquing. |
| } else if (isa<ClangModuleUnit>(typeDecl->getModuleScopeContext())) { |
| return emitForeignTypeMetadataRef(IGF, type); |
| } |
| |
| // Okay, everything else is built from a Swift metadata object. |
| llvm::Constant *metadata = IGF.IGM.getAddrOfTypeMetadata(type, false); |
| |
| // We should not be doing more serious work along this path. |
| assert(isTypeMetadataAccessTrivial(IGF.IGM, type)); |
| |
| return metadata; |
| } |
| |
| using MetadataAccessGenerator = |
| llvm::function_ref<llvm::Value*(IRGenFunction &IGF, llvm::Constant *cache)>; |
| |
| /// Get or create an accessor function to the given non-dependent type. |
| static llvm::Function *getTypeMetadataAccessFunction(IRGenModule &IGM, |
| CanType type, |
| ForDefinition_t shouldDefine, |
| MetadataAccessGenerator &&generator) { |
| assert(!type->hasArchetype()); |
| // Type should be bound unless it's type erased. |
| assert(isTypeErasedGenericClassType(type) |
| ? !isa<BoundGenericType>(type) |
| : !isa<UnboundGenericType>(type)); |
| |
| llvm::Function *accessor = |
| IGM.getAddrOfTypeMetadataAccessFunction(type, shouldDefine); |
| |
| // If we're not supposed to define the accessor, or if we already |
| // have defined it, just return the pointer. |
| if (!shouldDefine || !accessor->empty()) |
| return accessor; |
| |
| // Okay, define the accessor. |
| llvm::GlobalVariable *cacheVariable = nullptr; |
| |
| // If our preferred access method is to go via an accessor, it means |
| // there is some non-trivial computation that needs to be cached. |
| if (!isTypeMetadataAccessTrivial(IGM, type)) { |
| cacheVariable = cast<llvm::GlobalVariable>( |
| IGM.getAddrOfTypeMetadataLazyCacheVariable(type, ForDefinition)); |
| |
| if (IGM.getOptions().optimizeForSize()) |
| accessor->addFnAttr(llvm::Attribute::NoInline); |
| } |
| |
| emitLazyCacheAccessFunction(IGM, accessor, cacheVariable, |
| [&](IRGenFunction &IGF) -> llvm::Value* { |
| return generator(IGF, cacheVariable); |
| }); |
| |
| return accessor; |
| } |
| |
| /// Get or create an accessor function to the given non-dependent type. |
| static llvm::Function *getTypeMetadataAccessFunction(IRGenModule &IGM, |
| CanType type, |
| ForDefinition_t shouldDefine) { |
| return getTypeMetadataAccessFunction(IGM, type, shouldDefine, |
| [&](IRGenFunction &IGF, |
| llvm::Constant *cacheVariable) { |
| // We should not be called with ForDefinition for nominal types |
| // that require in-place initialization. |
| return emitTypeMetadataAccessFunctionBody(IGF, type); |
| }); |
| } |
| |
| /// Get or create an accessor function to the given generic type. |
| static llvm::Function *getGenericTypeMetadataAccessFunction(IRGenModule &IGM, |
| NominalTypeDecl *nominal, |
| ForDefinition_t shouldDefine) { |
| assert(nominal->isGenericContext()); |
| assert(!isTypeErasedGenericClass(nominal)); |
| |
| GenericArguments genericArgs; |
| genericArgs.collectTypes(IGM, nominal); |
| |
| llvm::Function *accessor = |
| IGM.getAddrOfGenericTypeMetadataAccessFunction( |
| nominal, genericArgs.Types, shouldDefine); |
| |
| // If we're not supposed to define the accessor, or if we already |
| // have defined it, just return the pointer. |
| if (!shouldDefine || !accessor->empty()) |
| return accessor; |
| |
| if (IGM.getOptions().optimizeForSize()) |
| accessor->addFnAttr(llvm::Attribute::NoInline); |
| |
| emitLazyCacheAccessFunction(IGM, accessor, /*cacheVariable=*/nullptr, |
| [&](IRGenFunction &IGF) -> llvm::Value* { |
| return emitGenericMetadataAccessFunction(IGF, nominal, genericArgs); |
| }); |
| |
| return accessor; |
| } |
| |
| /// Return the type metadata access function for the given type, if it |
| /// is guaranteed to exist. |
| static llvm::Constant * |
| getRequiredTypeMetadataAccessFunction(IRGenModule &IGM, |
| NominalTypeDecl *theDecl, |
| ForDefinition_t shouldDefine) { |
| if (!hasRequiredTypeMetadataAccessFunction(theDecl)) |
| return nullptr; |
| |
| if (theDecl->isGenericContext()) { |
| return getGenericTypeMetadataAccessFunction(IGM, theDecl, shouldDefine); |
| } |
| |
| CanType declaredType = theDecl->getDeclaredType()->getCanonicalType(); |
| return getTypeMetadataAccessFunction(IGM, declaredType, shouldDefine); |
| } |
| |
| /// Force a public metadata access function into existence if necessary |
| /// for the given type. |
| template <class BuilderTy> |
| static void maybeEmitNominalTypeMetadataAccessFunction(NominalTypeDecl *theDecl, |
| BuilderTy &builder) { |
| if (!hasRequiredTypeMetadataAccessFunction(theDecl)) |
| return; |
| |
| builder.createMetadataAccessFunction(); |
| } |
| |
| /// Emit a call to the type metadata accessor for the given function. |
| static llvm::Value *emitCallToTypeMetadataAccessFunction(IRGenFunction &IGF, |
| CanType type, |
| ForDefinition_t shouldDefine) { |
| // If we already cached the metadata, use it. |
| if (auto local = |
| IGF.tryGetLocalTypeData(type, LocalTypeDataKind::forTypeMetadata())) |
| return local; |
| |
| llvm::Constant *accessor = |
| getTypeMetadataAccessFunction(IGF.IGM, type, shouldDefine); |
| llvm::CallInst *call = IGF.Builder.CreateCall(accessor, {}); |
| call->setCallingConv(IGF.IGM.DefaultCC); |
| call->setDoesNotAccessMemory(); |
| call->setDoesNotThrow(); |
| |
| // Save the metadata for future lookups. |
| IGF.setScopedLocalTypeData(type, LocalTypeDataKind::forTypeMetadata(), call); |
| |
| return call; |
| } |
| |
| /// Produce the type metadata pointer for the given type. |
| llvm::Value *IRGenFunction::emitTypeMetadataRef(CanType type) { |
| type = getRuntimeReifiedType(IGM, type); |
| |
| if (type->hasArchetype() || |
| isTypeMetadataAccessTrivial(IGM, type)) { |
| return emitDirectTypeMetadataRef(*this, type); |
| } |
| |
| switch (getTypeMetadataAccessStrategy(type)) { |
| case MetadataAccessStrategy::PublicUniqueAccessor: |
| case MetadataAccessStrategy::HiddenUniqueAccessor: |
| case MetadataAccessStrategy::PrivateAccessor: |
| return emitCallToTypeMetadataAccessFunction(*this, type, NotForDefinition); |
| case MetadataAccessStrategy::NonUniqueAccessor: |
| return emitCallToTypeMetadataAccessFunction(*this, type, ForDefinition); |
| } |
| llvm_unreachable("bad type metadata access strategy"); |
| } |
| |
| /// Return the address of a function that will return type metadata |
| /// for the given non-dependent type. |
| llvm::Function *irgen::getOrCreateTypeMetadataAccessFunction(IRGenModule &IGM, |
| CanType type) { |
| type = getRuntimeReifiedType(IGM, type); |
| |
| assert(!type->hasArchetype() && |
| "cannot create global function to return dependent type metadata"); |
| |
| switch (getTypeMetadataAccessStrategy(type)) { |
| case MetadataAccessStrategy::PublicUniqueAccessor: |
| case MetadataAccessStrategy::HiddenUniqueAccessor: |
| case MetadataAccessStrategy::PrivateAccessor: |
| return getTypeMetadataAccessFunction(IGM, type, NotForDefinition); |
| case MetadataAccessStrategy::NonUniqueAccessor: |
| return getTypeMetadataAccessFunction(IGM, type, ForDefinition); |
| } |
| llvm_unreachable("bad type metadata access strategy"); |
| } |
| |
| namespace { |
| /// A visitor class for emitting a reference to a metatype object. |
| /// This implements a "raw" access, useful for implementing cache |
| /// functions or for implementing dependent accesses. |
| class EmitTypeMetadataRefForLayout |
| : public CanTypeVisitor<EmitTypeMetadataRefForLayout, llvm::Value *> { |
| private: |
| IRGenFunction &IGF; |
| public: |
| EmitTypeMetadataRefForLayout(IRGenFunction &IGF) : IGF(IGF) {} |
| |
| llvm::Value *emitDirectMetadataRef(CanType type) { |
| return IGF.IGM.getAddrOfTypeMetadata(type, /*pattern*/ false); |
| } |
| |
| /// For most types, we can just emit the usual metadata. |
| llvm::Value *visitType(CanType t) { |
| return IGF.emitTypeMetadataRef(t); |
| } |
| |
| llvm::Value *visitBoundGenericEnumType(CanBoundGenericEnumType type) { |
| // Optionals have a lowered payload type, so we recurse here. |
| if (auto objectTy = CanType(type).getAnyOptionalObjectType()) { |
| auto payloadMetadata = visit(objectTy); |
| llvm::Value *args[] = { payloadMetadata }; |
| llvm::Type *types[] = { IGF.IGM.TypeMetadataPtrTy }; |
| |
| // Call the generic metadata accessor function. |
| llvm::Function *accessor = |
| IGF.IGM.getAddrOfGenericTypeMetadataAccessFunction( |
| type->getDecl(), types, NotForDefinition); |
| |
| auto result = IGF.Builder.CreateCall(accessor, args); |
| result->setDoesNotThrow(); |
| result->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadNone); |
| |
| return result; |
| } |
| |
| // Otherwise, generic arguments are not lowered. |
| return visitType(type); |
| } |
| |
| llvm::Value *visitTupleType(CanTupleType type) { |
| if (auto cached = tryGetLocal(type)) |
| return cached; |
| |
| switch (type->getNumElements()) { |
| case 0: {// Special case the empty tuple, just use the global descriptor. |
| llvm::Constant *fullMetadata = IGF.IGM.getEmptyTupleMetadata(); |
| llvm::Constant *indices[] = { |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0), |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 1) |
| }; |
| return llvm::ConstantExpr::getInBoundsGetElementPtr( |
| /*Ty=*/nullptr, fullMetadata, indices); |
| } |
| |
| case 1: |
| // For layout purposes, we consider a singleton tuple to be |
| // isomorphic to its element type. |
| return visit(type.getElementType(0)); |
| |
| case 2: { |
| // Find the layout metadata pointers for these elements. |
| auto elt0Metadata = visit(type.getElementType(0)); |
| auto elt1Metadata = visit(type.getElementType(1)); |
| |
| llvm::Value *args[] = { |
| elt0Metadata, elt1Metadata, |
| // labels don't matter for layout |
| llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy), |
| llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed |
| }; |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadata2Fn(), |
| args); |
| call->setDoesNotThrow(); |
| return setLocal(CanType(type), call); |
| } |
| |
| case 3: { |
| // Find the layout metadata pointers for these elements. |
| auto elt0Metadata = visit(type.getElementType(0)); |
| auto elt1Metadata = visit(type.getElementType(1)); |
| auto elt2Metadata = visit(type.getElementType(2)); |
| |
| llvm::Value *args[] = { |
| elt0Metadata, elt1Metadata, elt2Metadata, |
| // labels don't matter for layout |
| llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy), |
| llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed |
| }; |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadata3Fn(), |
| args); |
| call->setDoesNotThrow(); |
| return setLocal(CanType(type), call); |
| } |
| default: |
| // TODO: use a caching entrypoint (with all information |
| // out-of-line) for non-dependent tuples. |
| |
| llvm::Value *pointerToFirst = nullptr; // appease -Wuninitialized |
| |
| auto elements = type.getElementTypes(); |
| auto arrayTy = llvm::ArrayType::get(IGF.IGM.TypeMetadataPtrTy, |
| elements.size()); |
| Address buffer = IGF.createAlloca(arrayTy,IGF.IGM.getPointerAlignment(), |
| "tuple-elements"); |
| IGF.Builder.CreateLifetimeStart(buffer, |
| IGF.IGM.getPointerSize() * elements.size()); |
| for (unsigned i = 0, e = elements.size(); i != e; ++i) { |
| // Find the metadata pointer for this element. |
| llvm::Value *eltMetadata = visit(elements[i]); |
| |
| // GEP to the appropriate element and store. |
| Address eltPtr = IGF.Builder.CreateStructGEP(buffer, i, |
| IGF.IGM.getPointerSize()); |
| IGF.Builder.CreateStore(eltMetadata, eltPtr); |
| |
| // Remember the GEP to the first element. |
| if (i == 0) pointerToFirst = eltPtr.getAddress(); |
| } |
| |
| llvm::Value *args[] = { |
| llvm::ConstantInt::get(IGF.IGM.SizeTy, elements.size()), |
| pointerToFirst, |
| // labels don't matter for layout |
| llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy), |
| llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed |
| }; |
| |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadataFn(), |
| args); |
| call->setDoesNotThrow(); |
| |
| IGF.Builder.CreateLifetimeEnd(buffer, |
| IGF.IGM.getPointerSize() * elements.size()); |
| |
| return setLocal(type, call); |
| } |
| } |
| |
| llvm::Value *visitAnyFunctionType(CanAnyFunctionType type) { |
| llvm_unreachable("not a SIL type"); |
| } |
| |
| llvm::Value *visitSILFunctionType(CanSILFunctionType type) { |
| // All function types have the same layout regardless of arguments or |
| // abstraction level. Use the metadata for () -> () for thick functions, |
| // or Builtin.UnknownObject for block functions. |
| auto &C = type->getASTContext(); |
| switch (type->getRepresentation()) { |
| case SILFunctionType::Representation::Thin: |
| case SILFunctionType::Representation::Method: |
| case SILFunctionType::Representation::WitnessMethod: |
| case SILFunctionType::Representation::ObjCMethod: |
| case SILFunctionType::Representation::CFunctionPointer: |
| case SILFunctionType::Representation::Closure: |
| // A thin function looks like a plain pointer. |
| // FIXME: Except for extra inhabitants? |
| return emitDirectMetadataRef(C.TheRawPointerType); |
| case SILFunctionType::Representation::Thick: |
| // All function types look like () -> (). |
| // FIXME: It'd be nice not to have to call through the runtime here. |
| return IGF.emitTypeMetadataRef( |
| CanFunctionType::get(AnyFunctionType::CanParamArrayRef(), |
| C.TheEmptyTupleType, |
| AnyFunctionType::ExtInfo())); |
| case SILFunctionType::Representation::Block: |
| // All block types look like Builtin.UnknownObject. |
| return emitDirectMetadataRef(C.TheUnknownObjectType); |
| } |
| |
| llvm_unreachable("Not a valid SILFunctionType."); |
| } |
| |
| llvm::Value *visitAnyMetatypeType(CanAnyMetatypeType type) { |
| |
| assert(type->hasRepresentation() |
| && "not a lowered metatype"); |
| |
| switch (type->getRepresentation()) { |
| case MetatypeRepresentation::Thin: { |
| // Thin metatypes are empty, so they look like the empty tuple type. |
| llvm::Constant *fullMetadata = IGF.IGM.getEmptyTupleMetadata(); |
| llvm::Constant *indices[] = { |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0), |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 1) |
| }; |
| return llvm::ConstantExpr::getInBoundsGetElementPtr( |
| /*Ty=*/nullptr, fullMetadata, indices); |
| } |
| case MetatypeRepresentation::Thick: |
| case MetatypeRepresentation::ObjC: |
| // Thick and ObjC metatypes look like pointers with extra inhabitants. |
| // Get the metatype metadata from the runtime. |
| // FIXME: It'd be nice not to need a runtime call here. |
| return IGF.emitTypeMetadataRef(type); |
| } |
| |
| llvm_unreachable("Not a valid MetatypeRepresentation."); |
| } |
| |
| /// Try to find the metatype in local data. |
| llvm::Value *tryGetLocal(CanType type) { |
| return IGF.tryGetLocalTypeDataForLayout( |
| IGF.IGM.getLoweredType(type), |
| LocalTypeDataKind::forTypeMetadata()); |
| } |
| |
| /// Set the metatype in local data. |
| llvm::Value *setLocal(CanType type, llvm::Instruction *metatype) { |
| IGF.setScopedLocalTypeDataForLayout(IGF.IGM.getLoweredType(type), |
| LocalTypeDataKind::forTypeMetadata(), |
| metatype); |
| return metatype; |
| } |
| }; |
| } // end anonymous namespace |
| |
| llvm::Value *IRGenFunction::emitTypeMetadataRefForLayout(SILType type) { |
| return EmitTypeMetadataRefForLayout(*this).visit(type.getSwiftRValueType()); |
| } |
| |
| namespace { |
| |
| /// A visitor class for emitting a reference to a type layout struct. |
| /// There are a few ways we can emit it: |
| /// |
| /// - If the type is fixed-layout and we have visibility of its value |
| /// witness table (or one close enough), we can project the layout struct |
| /// from it. |
| /// - If the type is fixed layout, we can emit our own copy of the layout |
| /// struct. |
| /// - If the type is dynamic-layout, we have to instantiate its metadata |
| /// and project out its metadata. (FIXME: This leads to deadlocks in |
| /// recursive cases, though we can avoid many deadlocks because most |
| /// valid recursive types bottom out in fixed-sized types like classes |
| /// or pointers.) |
| class EmitTypeLayoutRef |
| : public CanTypeVisitor<EmitTypeLayoutRef, llvm::Value *> { |
| private: |
| IRGenFunction &IGF; |
| public: |
| EmitTypeLayoutRef(IRGenFunction &IGF) : IGF(IGF) {} |
| |
| llvm::Value *emitFromValueWitnessTablePointer(llvm::Value *vwtable) { |
| llvm::Value *indexConstant = llvm::ConstantInt::get(IGF.IGM.Int32Ty, |
| (unsigned)ValueWitness::First_TypeLayoutWitness); |
| return IGF.Builder.CreateInBoundsGEP(IGF.IGM.Int8PtrTy, vwtable, |
| indexConstant); |
| } |
| |
| /// Emit the type layout by projecting it from a value witness table to |
| /// which we have linkage. |
| llvm::Value *emitFromValueWitnessTable(CanType t) { |
| auto *vwtable = IGF.IGM.getAddrOfValueWitnessTable(t); |
| return emitFromValueWitnessTablePointer(vwtable); |
| } |
| |
| /// Emit the type layout by projecting it from dynamic type metadata. |
| llvm::Value *emitFromTypeMetadata(CanType t) { |
| auto *vwtable = IGF.emitValueWitnessTableRef(IGF.IGM.getLoweredType(t)); |
| return emitFromValueWitnessTablePointer(vwtable); |
| } |
| |
| bool hasVisibleValueWitnessTable(CanType t) const { |
| // Some builtin and structural types have value witnesses exported from |
| // the runtime. |
| auto &C = IGF.IGM.Context; |
| if (t == C.TheEmptyTupleType |
| || t == C.TheNativeObjectType |
| || t == C.TheUnknownObjectType |
| || t == C.TheBridgeObjectType |
| || t == C.TheRawPointerType) |
| return true; |
| if (auto intTy = dyn_cast<BuiltinIntegerType>(t)) { |
| auto width = intTy->getWidth(); |
| if (width.isPointerWidth()) |
| return true; |
| if (width.isFixedWidth()) { |
| switch (width.getFixedWidth()) { |
| case 8: |
| case 16: |
| case 32: |
| case 64: |
| case 128: |
| case 256: |
| return true; |
| default: |
| return false; |
| } |
| } |
| return false; |
| } |
| |
| // TODO: If a nominal type is in the same source file as we're currently |
| // emitting, we would be able to see its value witness table. |
| return false; |
| } |
| |
| /// Fallback default implementation. |
| llvm::Value *visitType(CanType t) { |
| auto silTy = IGF.IGM.getLoweredType(t); |
| auto &ti = IGF.getTypeInfo(silTy); |
| |
| // If the type is in the same source file, or has a common value |
| // witness table exported from the runtime, we can project from the |
| // value witness table instead of emitting a new record. |
| if (hasVisibleValueWitnessTable(t)) |
| return emitFromValueWitnessTable(t); |
| |
| // If the type is a singleton aggregate, the field's layout is equivalent |
| // to the aggregate's. |
| if (SILType singletonFieldTy = getSingletonAggregateFieldType(IGF.IGM, |
| silTy, ResilienceExpansion::Maximal)) |
| return visit(singletonFieldTy.getSwiftRValueType()); |
| |
| // If the type is fixed-layout, emit a copy of its layout. |
| if (auto fixed = dyn_cast<FixedTypeInfo>(&ti)) |
| return IGF.IGM.emitFixedTypeLayout(t, *fixed); |
| |
| return emitFromTypeMetadata(t); |
| } |
| |
| llvm::Value *visitAnyFunctionType(CanAnyFunctionType type) { |
| llvm_unreachable("not a SIL type"); |
| } |
| |
| llvm::Value *visitSILFunctionType(CanSILFunctionType type) { |
| // All function types have the same layout regardless of arguments or |
| // abstraction level. Use the value witness table for |
| // @convention(blah) () -> () from the runtime. |
| auto &C = type->getASTContext(); |
| switch (type->getRepresentation()) { |
| case SILFunctionType::Representation::Thin: |
| case SILFunctionType::Representation::Method: |
| case SILFunctionType::Representation::WitnessMethod: |
| case SILFunctionType::Representation::ObjCMethod: |
| case SILFunctionType::Representation::CFunctionPointer: |
| case SILFunctionType::Representation::Closure: |
| // A thin function looks like a plain pointer. |
| // FIXME: Except for extra inhabitants? |
| return emitFromValueWitnessTable(C.TheRawPointerType); |
| case SILFunctionType::Representation::Thick: |
| // All function types look like () -> (). |
| return emitFromValueWitnessTable( |
| CanFunctionType::get(AnyFunctionType::CanParamArrayRef(), |
| C.TheEmptyTupleType, |
| AnyFunctionType::ExtInfo())); |
| case SILFunctionType::Representation::Block: |
| // All block types look like Builtin.UnknownObject. |
| return emitFromValueWitnessTable(C.TheUnknownObjectType); |
| } |
| |
| llvm_unreachable("Not a valid SILFunctionType."); |
| } |
| |
| llvm::Value *visitAnyMetatypeType(CanAnyMetatypeType type) { |
| |
| assert(type->hasRepresentation() |
| && "not a lowered metatype"); |
| |
| switch (type->getRepresentation()) { |
| case MetatypeRepresentation::Thin: { |
| // Thin metatypes are empty, so they look like the empty tuple type. |
| return emitFromValueWitnessTable(IGF.IGM.Context.TheEmptyTupleType); |
| } |
| case MetatypeRepresentation::Thick: |
| case MetatypeRepresentation::ObjC: |
| // Thick metatypes look like pointers with spare bits. |
| return emitFromValueWitnessTable( |
| CanMetatypeType::get(IGF.IGM.Context.TheNativeObjectType)); |
| } |
| |
| llvm_unreachable("Not a valid MetatypeRepresentation."); |
| } |
| |
| llvm::Value *visitAnyClassType(ClassDecl *classDecl) { |
| // All class types have the same layout. |
| auto type = classDecl->getDeclaredType()->getCanonicalType(); |
| switch (getReferenceCountingForType(IGF.IGM, type)) { |
| case ReferenceCounting::Native: |
| return emitFromValueWitnessTable(IGF.IGM.Context.TheNativeObjectType); |
| |
| case ReferenceCounting::ObjC: |
| case ReferenceCounting::Block: |
| case ReferenceCounting::Unknown: |
| return emitFromValueWitnessTable(IGF.IGM.Context.TheUnknownObjectType); |
| |
| case ReferenceCounting::Bridge: |
| case ReferenceCounting::Error: |
| llvm_unreachable("classes shouldn't have this kind of refcounting"); |
| } |
| |
| llvm_unreachable("Not a valid ReferenceCounting."); |
| } |
| |
| llvm::Value *visitClassType(CanClassType type) { |
| return visitAnyClassType(type->getClassOrBoundGenericClass()); |
| } |
| |
| llvm::Value *visitBoundGenericClassType(CanBoundGenericClassType type) { |
| return visitAnyClassType(type->getClassOrBoundGenericClass()); |
| } |
| |
| llvm::Value *visitReferenceStorageType(CanReferenceStorageType type) { |
| // Other reference storage types all have the same layout for their |
| // storage qualification and the reference counting of their underlying |
| // object. |
| |
| auto &C = IGF.IGM.Context; |
| CanType referent; |
| switch (type->getOwnership()) { |
| case Ownership::Strong: |
| llvm_unreachable("shouldn't be a ReferenceStorageType"); |
| case Ownership::Weak: |
| referent = type.getReferentType().getAnyOptionalObjectType(); |
| break; |
| case Ownership::Unmanaged: |
| case Ownership::Unowned: |
| referent = type.getReferentType(); |
| break; |
| } |
| |
| // Reference storage types with witness tables need open-coded layouts. |
| // TODO: Maybe we could provide prefabs for 1 witness table. |
| if (referent.isExistentialType()) { |
| auto layout = referent.getExistentialLayout(); |
| for (auto *protoTy : layout.getProtocols()) { |
| auto *protoDecl = protoTy->getDecl(); |
| if (IGF.getSILTypes().protocolRequiresWitnessTable(protoDecl)) |
| return visitType(type); |
| } |
| } |
| |
| // Unmanaged references are plain pointers with extra inhabitants, |
| // which look like thick metatypes. |
| // |
| // FIXME: This sounds wrong, an Objective-C tagged pointer could be |
| // stored in an unmanaged reference for instance. |
| if (type->getOwnership() == Ownership::Unmanaged) { |
| auto metatype = CanMetatypeType::get(C.TheNativeObjectType); |
| return emitFromValueWitnessTable(metatype); |
| } |
| |
| CanType valueWitnessReferent; |
| switch (getReferenceCountingForType(IGF.IGM, referent)) { |
| case ReferenceCounting::Unknown: |
| case ReferenceCounting::Block: |
| case ReferenceCounting::ObjC: |
| valueWitnessReferent = C.TheUnknownObjectType; |
| break; |
| |
| case ReferenceCounting::Native: |
| valueWitnessReferent = C.TheNativeObjectType; |
| break; |
| |
| case ReferenceCounting::Bridge: |
| valueWitnessReferent = C.TheBridgeObjectType; |
| break; |
| |
| case ReferenceCounting::Error: |
| llvm_unreachable("shouldn't be possible"); |
| } |
| |
| // Get the reference storage type of the builtin object whose value |
| // witness we can borrow. |
| if (type->getOwnership() == Ownership::Weak) |
| valueWitnessReferent = OptionalType::get(valueWitnessReferent) |
| ->getCanonicalType(); |
| |
| auto valueWitnessType = CanReferenceStorageType::get(valueWitnessReferent, |
| type->getOwnership()); |
| return emitFromValueWitnessTable(valueWitnessType); |
| } |
| }; |
| |
| } // end anonymous namespace |
| |
| llvm::Value *IRGenFunction::emitTypeLayoutRef(SILType type) { |
| return EmitTypeLayoutRef(*this).visit(type.getSwiftRValueType()); |
| } |
| |
| void IRGenModule::setTrueConstGlobal(llvm::GlobalVariable *var) { |
| switch (TargetInfo.OutputObjectFormat) { |
| case llvm::Triple::UnknownObjectFormat: |
| llvm_unreachable("unknown object format"); |
| case llvm::Triple::MachO: |
| var->setSection("__TEXT,__const"); |
| break; |
| case llvm::Triple::ELF: |
| var->setSection(".rodata"); |
| break; |
| case llvm::Triple::COFF: |
| var->setSection(".rdata"); |
| break; |
| case llvm::Triple::Wasm: |
| llvm_unreachable("web assembly object format is not supported."); |
| break; |
| } |
| } |
| |
| /// Produce the heap metadata pointer for the given class type. For |
| /// Swift-defined types, this is equivalent to the metatype for the |
| /// class, but for Objective-C-defined types, this is the class |
| /// object. |
| llvm::Value *irgen::emitClassHeapMetadataRef(IRGenFunction &IGF, CanType type, |
| MetadataValueType desiredType, |
| bool allowUninitialized) { |
| assert(type->mayHaveSuperclass()); |
| |
| // Archetypes may or may not be ObjC classes and need unwrapping to get at |
| // the class object. |
| if (auto archetype = dyn_cast<ArchetypeType>(type)) { |
| // Look up the Swift metadata from context. |
| llvm::Value *archetypeMeta = IGF.emitTypeMetadataRef(type); |
| // Get the class pointer. |
| auto classPtr = emitClassHeapMetadataRefForMetatype(IGF, archetypeMeta, |
| archetype); |
| if (desiredType == MetadataValueType::ObjCClass) |
| classPtr = IGF.Builder.CreateBitCast(classPtr, IGF.IGM.ObjCClassPtrTy); |
| return classPtr; |
| } |
| |
| if (ClassDecl *theClass = type->getClassOrBoundGenericClass()) { |
| if (!hasKnownSwiftMetadata(IGF.IGM, theClass)) { |
| llvm::Value *result = |
| emitObjCHeapMetadataRef(IGF, theClass, allowUninitialized); |
| if (desiredType == MetadataValueType::TypeMetadata) |
| result = IGF.Builder.CreateBitCast(result, IGF.IGM.TypeMetadataPtrTy); |
| return result; |
| } |
| } |
| |
| llvm::Value *result = IGF.emitTypeMetadataRef(type); |
| if (desiredType == MetadataValueType::ObjCClass) |
| result = IGF.Builder.CreateBitCast(result, IGF.IGM.ObjCClassPtrTy); |
| return result; |
| } |
| |
| /// Emit a metatype value for a known type. |
| void irgen::emitMetatypeRef(IRGenFunction &IGF, CanMetatypeType type, |
| Explosion &explosion) { |
| switch (type->getRepresentation()) { |
| case MetatypeRepresentation::Thin: |
| // Thin types have a trivial representation. |
| break; |
| |
| case MetatypeRepresentation::Thick: |
| explosion.add(IGF.emitTypeMetadataRef(type.getInstanceType())); |
| break; |
| |
| case MetatypeRepresentation::ObjC: |
| explosion.add(emitClassHeapMetadataRef(IGF, type.getInstanceType(), |
| MetadataValueType::ObjCClass)); |
| break; |
| } |
| } |
| |
| /*****************************************************************************/ |
| /** Nominal Type Descriptor Emission *****************************************/ |
| /*****************************************************************************/ |
| |
| template <class Flags> |
| static Flags getMethodDescriptorFlags(ValueDecl *fn) { |
| if (isa<ConstructorDecl>(fn)) |
| return Flags(Flags::Kind::Init); // 'init' is considered static |
| |
| auto kind = [&] { |
| switch (cast<FuncDecl>(fn)->getAccessorKind()) { |
| case AccessorKind::NotAccessor: |
| return Flags::Kind::Method; |
| case AccessorKind::IsGetter: |
| return Flags::Kind::Getter; |
| case AccessorKind::IsSetter: |
| return Flags::Kind::Setter; |
| case AccessorKind::IsMaterializeForSet: |
| return Flags::Kind::MaterializeForSet; |
| case AccessorKind::IsWillSet: |
| case AccessorKind::IsDidSet: |
| case AccessorKind::IsAddressor: |
| case AccessorKind::IsMutableAddressor: |
| llvm_unreachable("these accessors never appear in protocols or v-tables"); |
| } |
| llvm_unreachable("bad kind"); |
| }(); |
| return Flags(kind).withIsInstance(!fn->isStatic()); |
| } |
| |
| namespace { |
| template<class Impl> |
| class NominalTypeDescriptorBuilderBase { |
| protected: |
| Impl &asImpl() { return *static_cast<Impl*>(this); } |
| IRGenModule &IGM; |
| private: |
| ConstantInitBuilder InitBuilder; |
| protected: |
| ConstantStructBuilder B; |
| |
| NominalTypeDescriptorBuilderBase(IRGenModule &IGM) |
| : IGM(IGM), InitBuilder(IGM), B(InitBuilder.beginStruct()) { |
| B.setPacked(true); |
| } |
| |
| public: |
| void layout() { |
| asImpl().addName(); |
| asImpl().addKindDependentFields(); |
| asImpl().addKind(); |
| asImpl().addAccessFunction(); |
| asImpl().addGenericParams(); |
| } |
| |
| CanType getAbstractType() { |
| return asImpl().getTarget()->getDeclaredType()->getCanonicalType(); |
| } |
| |
| void addName() { |
| B.addRelativeAddress(getMangledTypeName(IGM, getAbstractType(), |
| /*willBeRelativelyAddressed*/ true)); |
| } |
| |
| void addKind() { |
| auto kind = asImpl().getKind(); |
| B.addInt32(kind); |
| } |
| |
| void addAccessFunction() { |
| NominalTypeDecl *typeDecl = asImpl().getTarget(); |
| llvm::Constant *accessFn = |
| getRequiredTypeMetadataAccessFunction(IGM, typeDecl, NotForDefinition); |
| B.addRelativeAddressOrNull(accessFn); |
| } |
| |
| void addGenericParams() { |
| NominalTypeDecl *ntd = asImpl().getTarget(); |
| |
| // uint32_t GenericParameterVectorOffset; |
| B.addInt32(asImpl().getGenericParamsOffset() / IGM.getPointerSize()); |
| |
| // The archetype order here needs to be consistent with |
| // MetadataVisitor::addGenericFields. |
| |
| GenericTypeRequirements requirements(IGM, ntd); |
| |
| // uint32_t NumGenericRequirements; |
| B.addInt32(requirements.getStorageSizeInWords()); |
| |
| // uint32_t NumPrimaryGenericParameters; |
| B.addInt32(requirements.getNumTypeRequirements()); |
| |
| // GenericParameterDescriptorFlags Flags; |
| GenericParameterDescriptorFlags flags; |
| if (auto *cd = dyn_cast<ClassDecl>(ntd)) { |
| auto &layout = IGM.getMetadataLayout(cd); |
| if (layout.getVTableSize() > 0) |
| flags = flags.withHasVTable(true); |
| } |
| |
| // Calculate the number of generic parameters at each nesting depth. |
| unsigned totalGenericParams = 0; |
| SmallVector<unsigned, 2> numPrimaryParams; |
| for (auto *outer = ntd; outer != nullptr; |
| outer = outer->getDeclContext() |
| ->getAsNominalTypeOrNominalTypeExtensionContext()) { |
| unsigned genericParamsAtDepth = 0; |
| if (auto *genericParams = outer->getGenericParams()) { |
| for (auto *paramDecl : *genericParams) { |
| auto contextTy = ntd->mapTypeIntoContext( |
| paramDecl->getDeclaredInterfaceType()); |
| // Skip parameters which have been made concrete, because they do |
| // not appear in type metadata. |
| // |
| // FIXME: We should emit information about same-type constraints |
| // as well as conformance constraints, so that clients can |
| // reconstruct the full generic signature of the type, including |
| // fully-concrete parameters. |
| if (contextTy->is<ArchetypeType>()) { |
| totalGenericParams++; |
| genericParamsAtDepth++; |
| } |
| } |
| } |
| numPrimaryParams.push_back(genericParamsAtDepth); |
| } |
| |
| // This assertion will fail once we have generic types nested |
| // inside generic functions or other local generic contexts. |
| assert(totalGenericParams == requirements.getNumTypeRequirements()); |
| |
| // Emit the nesting depth. |
| B.addInt16(numPrimaryParams.size()); |
| |
| // Emit the flags. |
| B.addInt16(flags.getIntValue()); |
| |
| // Emit the number of generic parameters at each nesting depth. |
| std::reverse(numPrimaryParams.begin(), numPrimaryParams.end()); |
| for (auto count : numPrimaryParams) |
| B.addInt32(count); |
| |
| // TODO: provide reflective descriptions of the type and |
| // conformance requirements stored here. |
| } |
| |
| llvm::Constant *emit() { |
| asImpl().layout(); |
| |
| auto addr = IGM.getAddrOfNominalTypeDescriptor(asImpl().getTarget(), |
| B.finishAndCreateFuture()); |
| auto var = cast<llvm::GlobalVariable>(addr); |
| |
| var->setConstant(true); |
| IGM.setTrueConstGlobal(var); |
| |
| return var; |
| } |
| |
| // Derived class must provide: |
| // NominalTypeDecl *getTarget(); |
| // unsigned getKind(); |
| // unsigned getGenericParamsOffset(); |
| // void addKindDependentFields(); |
| }; |
| |
| /// Build a doubly-null-terminated list of field names. |
| template<typename ValueDeclRange> |
| unsigned getFieldNameString(const ValueDeclRange &fields, |
| llvm::SmallVectorImpl<char> &out) { |
| unsigned numFields = 0; |
| |
| { |
| llvm::raw_svector_ostream os(out); |
| |
| for (ValueDecl *prop : fields) { |
| os << prop->getBaseName() << '\0'; |
| ++numFields; |
| } |
| // The final null terminator is provided by getAddrOfGlobalString. |
| } |
| return numFields; |
| } |
| |
| /// Build the field type vector accessor for a nominal type. This is a |
| /// function that lazily instantiates the type metadata for all of the |
| /// types of the stored properties of an instance of a nominal type. |
| static llvm::Function * |
| getFieldTypeAccessorFn(IRGenModule &IGM, |
| NominalTypeDecl *type, |
| ArrayRef<FieldTypeInfo> fieldTypes) { |
| // The accessor function has the following signature: |
| // const Metadata * const *(*GetFieldTypes)(const Metadata *T); |
| auto metadataArrayPtrTy = IGM.TypeMetadataPtrTy->getPointerTo(); |
| auto fnTy = llvm::FunctionType::get(metadataArrayPtrTy, |
| IGM.TypeMetadataPtrTy, |
| /*vararg*/ false); |
| auto fn = llvm::Function::Create(fnTy, llvm::GlobalValue::PrivateLinkage, |
| llvm::Twine("get_field_types_") |
| + type->getName().str(), |
| IGM.getModule()); |
| fn->setAttributes(IGM.constructInitialAttributes()); |
| |
| // Emit the body of the field type accessor later. We need to access |
| // the type metadata for the fields, which could lead to infinite recursion |
| // in recursive types if we build the field type accessor during metadata |
| // generation. |
| IGM.addLazyFieldTypeAccessor(type, fieldTypes, fn); |
| |
| return fn; |
| } |
| |
| /// Build a field type accessor for stored properties. |
| static llvm::Function * |
| getFieldTypeAccessorFn(IRGenModule &IGM, |
| NominalTypeDecl *type, |
| NominalTypeDecl::StoredPropertyRange storedProperties){ |
| SmallVector<FieldTypeInfo, 4> types; |
| for (VarDecl *prop : storedProperties) { |
| auto propertyType = type->mapTypeIntoContext(prop->getInterfaceType()) |
| ->getCanonicalType(); |
| types.push_back(FieldTypeInfo(propertyType, |
| /*indirect*/ false, |
| propertyType->is<WeakStorageType>())); |
| } |
| return getFieldTypeAccessorFn(IGM, type, types); |
| } |
| |
| /// Build a case type accessor for enum payloads. |
| static llvm::Function * |
| getFieldTypeAccessorFn(IRGenModule &IGM, |
| NominalTypeDecl *type, |
| ArrayRef<EnumImplStrategy::Element> enumElements) { |
| SmallVector<FieldTypeInfo, 4> types; |
| |
| // This is a terrible special case, but otherwise the archetypes |
| // aren't mapped correctly because the EnumImplStrategy ends up |
| // using the lowered cases, i.e. the cases for Optional<>. |
| if (type->classifyAsOptionalType() == OTK_ImplicitlyUnwrappedOptional) { |
| assert(enumElements.size() == 1); |
| auto decl = IGM.Context.getImplicitlyUnwrappedOptionalSomeDecl(); |
| auto caseType = decl->getParentEnum()->mapTypeIntoContext( |
| decl->getArgumentInterfaceType()) |
| ->getCanonicalType(); |
| types.push_back(FieldTypeInfo(caseType, false, false)); |
| return getFieldTypeAccessorFn(IGM, type, types); |
| } |
| |
| for (auto &elt : enumElements) { |
| auto caseType = elt.decl->getParentEnum()->mapTypeIntoContext( |
| elt.decl->getArgumentInterfaceType()) |
| ->getCanonicalType(); |
| bool isIndirect = elt.decl->isIndirect() |
| || elt.decl->getParentEnum()->isIndirect(); |
| types.push_back(FieldTypeInfo(caseType, isIndirect, /*weak*/ false)); |
| } |
| return getFieldTypeAccessorFn(IGM, type, types); |
| } |
| |
| class StructNominalTypeDescriptorBuilder |
| : public NominalTypeDescriptorBuilderBase<StructNominalTypeDescriptorBuilder> |
| { |
| using super |
| = NominalTypeDescriptorBuilderBase<StructNominalTypeDescriptorBuilder>; |
| |
| // Offsets of key fields in the metadata records. |
| Size FieldVectorOffset, GenericParamsOffset; |
| |
| StructDecl *Target; |
| |
| public: |
| StructNominalTypeDescriptorBuilder(IRGenModule &IGM, |
| StructDecl *s) |
| : super(IGM), Target(s) |
| { |
| auto &layout = IGM.getMetadataLayout(Target); |
| FieldVectorOffset = layout.getFieldOffsetVectorOffset().getStatic(); |
| GenericParamsOffset = layout.getStaticGenericRequirementsOffset(); |
| } |
| |
| StructDecl *getTarget() { return Target; } |
| |
| unsigned getKind() { |
| return unsigned(NominalTypeKind::Struct); |
| } |
| |
| Size getGenericParamsOffset() { |
| return GenericParamsOffset; |
| } |
| |
| void addKindDependentFields() { |
| // Build the field name list. |
| llvm::SmallString<64> fieldNames; |
| unsigned numFields = getFieldNameString(Target->getStoredProperties(), |
| fieldNames); |
| |
| B.addInt32(numFields); |
| B.addInt32(FieldVectorOffset / IGM.getPointerSize()); |
| B.addRelativeAddress(IGM.getAddrOfGlobalString(fieldNames, |
| /*willBeRelativelyAddressed*/ true)); |
| |
| // Build the field type accessor function. |
| llvm::Function *fieldTypeVectorAccessor |
| = getFieldTypeAccessorFn(IGM, Target, |
| Target->getStoredProperties()); |
| |
| B.addRelativeAddress(fieldTypeVectorAccessor); |
| } |
| }; |
| |
| class ClassNominalTypeDescriptorBuilder |
| : public NominalTypeDescriptorBuilderBase<ClassNominalTypeDescriptorBuilder>, |
| public SILVTableVisitor<ClassNominalTypeDescriptorBuilder> |
| { |
| using super |
| = NominalTypeDescriptorBuilderBase<ClassNominalTypeDescriptorBuilder>; |
| |
| // Offsets of key fields in the metadata records. |
| Size FieldVectorOffset, GenericParamsOffset; |
| |
| SILVTable *VTable; |
| |
| Size VTableOffset; |
| unsigned VTableSize; |
| |
| ClassDecl *Target; |
| |
| public: |
| ClassNominalTypeDescriptorBuilder(IRGenModule &IGM, |
| ClassDecl *c) |
| : super(IGM), |
| SILVTableVisitor<ClassNominalTypeDescriptorBuilder>(IGM.getSILTypes()), |
| Target(c) |
| { |
| auto &layout = IGM.getMetadataLayout(Target); |
| FieldVectorOffset = layout.getStaticFieldOffsetVectorOffset(); |
| GenericParamsOffset = layout.getStaticGenericRequirementsOffset(); |
| |
| VTable = IGM.getSILModule().lookUpVTable(Target); |
| |
| VTableOffset = layout.getStaticVTableOffset(); |
| VTableSize = layout.getVTableSize(); |
| } |
| |
| ClassDecl *getTarget() { return Target; } |
| |
| unsigned getKind() { |
| return unsigned(NominalTypeKind::Class); |
| } |
| |
| Size getGenericParamsOffset() { |
| return GenericParamsOffset; |
| } |
| |
| void addKindDependentFields() { |
| // Build the field name list. |
| llvm::SmallString<64> fieldNames; |
| unsigned numFields = getFieldNameString(Target->getStoredProperties(), |
| fieldNames); |
| |
| B.addInt32(numFields); |
| B.addInt32(FieldVectorOffset / IGM.getPointerSize()); |
| B.addRelativeAddress(IGM.getAddrOfGlobalString(fieldNames, |
| /*willBeRelativelyAddressed*/ true)); |
| |
| // Build the field type accessor function. |
| llvm::Function *fieldTypeVectorAccessor |
| = getFieldTypeAccessorFn(IGM, Target, |
| Target->getStoredProperties()); |
| |
| B.addRelativeAddress(fieldTypeVectorAccessor); |
| } |
| |
| void addVTableDescriptor() { |
| assert(VTableSize != 0); |
| B.addInt32(VTableOffset / IGM.getPointerSize()); |
| B.addInt32(VTableSize); |
| |
| addVTableEntries(Target); |
| |
| // TODO: Emit reflection metadata for virtual methods |
| } |
| |
| void addMethod(SILDeclRef fn) { |
| assert(VTable && "no vtable?!"); |
| |
| auto descriptor = B.beginStruct(IGM.MethodDescriptorStructTy); |
| |
| // Classify the method. |
| using Flags = MethodDescriptorFlags; |
| auto flags = getMethodDescriptorFlags<Flags>(fn.getDecl()); |
| |
| // Remember if the declaration was dynamic. |
| if (fn.getDecl()->isDynamic()) |
| flags = flags.withIsDynamic(true); |
| |
| // TODO: final? open? |
| |
| auto *dc = fn.getDecl()->getDeclContext(); |
| assert(!isa<ExtensionDecl>(dc)); |
| |
| if (fn.getDecl()->getDeclContext() == Target) { |
| if (auto entry = VTable->getEntry(IGM.getSILModule(), fn)) { |
| assert(entry->TheKind == SILVTable::Entry::Kind::Normal); |
| auto *implFn = IGM.getAddrOfSILFunction(entry->Implementation, |
| NotForDefinition); |
| descriptor.addRelativeAddress(implFn); |
| } else { |
| // The method is removed by dead method elimination. |
| // It should be never called. We add a pointer to an error function. |
| descriptor.addRelativeAddressOrNull(nullptr); |
| } |
| } |
| |
| descriptor.addInt(IGM.Int32Ty, flags.getIntValue()); |
| |
| descriptor.finishAndAddTo(B); |
| } |
| |
| void addMethodOverride(SILDeclRef baseRef, SILDeclRef declRef) {} |
| |
| void addPlaceholder(MissingMemberDecl *MMD) { |
| llvm_unreachable("cannot generate metadata with placeholders in it"); |
| } |
| |
| void layout() { |
| super::layout(); |
| if (VTableSize != 0) |
| addVTableDescriptor(); |
| } |
| }; |
| |
| class EnumNominalTypeDescriptorBuilder |
| : public NominalTypeDescriptorBuilderBase<EnumNominalTypeDescriptorBuilder> |
| { |
| using super |
| = NominalTypeDescriptorBuilderBase<EnumNominalTypeDescriptorBuilder>; |
| |
| // Offsets of key fields in the metadata records. |
| Size GenericParamsOffset; |
| Size PayloadSizeOffset; |
| |
| EnumDecl *Target; |
| |
| public: |
| EnumNominalTypeDescriptorBuilder(IRGenModule &IGM, EnumDecl *c) |
| : super(IGM), Target(c) |
| { |
| auto &layout = IGM.getMetadataLayout(Target); |
| GenericParamsOffset = layout.getStaticGenericRequirementsOffset(); |
| if (layout.hasPayloadSizeOffset()) |
| PayloadSizeOffset = layout.getPayloadSizeOffset().getStatic(); |
| } |
| |
| EnumDecl *getTarget() { return Target; } |
| |
| unsigned getKind() { |
| return unsigned(NominalTypeKind::Enum); |
| } |
| |
| Size getGenericParamsOffset() { |
| return GenericParamsOffset; |
| } |
| |
| void addKindDependentFields() { |
| auto &strategy = getEnumImplStrategy(IGM, |
| Target->getDeclaredTypeInContext()->getCanonicalType()); |
| |
| |
| // # payload cases in the low 24 bits, payload size offset in the high 8. |
| unsigned numPayloads = strategy.getElementsWithPayload().size(); |
| assert(numPayloads < (1<<24) && "too many payload elements for runtime"); |
| assert(PayloadSizeOffset % IGM.getPointerAlignment() == Size(0) |
| && "payload size not word-aligned"); |
| unsigned PayloadSizeOffsetInWords |
| = PayloadSizeOffset / IGM.getPointerSize(); |
| assert(PayloadSizeOffsetInWords < 0x100 && |
| "payload size offset too far from address point for runtime"); |
| B.addInt32(numPayloads | (PayloadSizeOffsetInWords << 24)); |
| // # empty cases |
| B.addInt32(strategy.getElementsWithNoPayload().size()); |
| |
| B.addRelativeAddressOrNull(strategy.emitCaseNames()); |
| |
| // Build the case type accessor. |
| llvm::Function *caseTypeVectorAccessor |
| = getFieldTypeAccessorFn(IGM, Target, |
| strategy.getElementsWithPayload()); |
| |
| B.addRelativeAddress(caseTypeVectorAccessor); |
| } |
| }; |
| |
| } // end anonymous namespace |
| |
| void |
| IRGenModule::addLazyFieldTypeAccessor(NominalTypeDecl *type, |
| ArrayRef<FieldTypeInfo> fieldTypes, |
| llvm::Function *fn) { |
| IRGen.addLazyFieldTypeAccessor(type, fieldTypes, fn, this); |
| } |
| |
| void |
| irgen::emitFieldTypeAccessor(IRGenModule &IGM, |
| NominalTypeDecl *type, |
| llvm::Function *fn, |
| ArrayRef<FieldTypeInfo> fieldTypes) |
| { |
| IRGenFunction IGF(IGM, fn); |
| if (IGM.DebugInfo) |
| IGM.DebugInfo->emitArtificialFunction(IGF, fn); |
| |
| auto metadataArrayPtrTy = IGM.TypeMetadataPtrTy->getPointerTo(); |
| |
| CanType formalType = type->getDeclaredTypeInContext()->getCanonicalType(); |
| llvm::Value *metadata = IGF.collectParameters().claimNext(); |
| setTypeMetadataName(IGM, metadata, formalType); |
| |
| // Get the address at which the field type vector reference should be |
| // cached. |
| llvm::Value *vectorPtr; |
| auto nullVector = llvm::ConstantPointerNull::get(metadataArrayPtrTy); |
| |
| // If the type is not generic, we can use a global variable to cache the |
| // address of the field type vector for the single instance. |
| if (!type->isGenericContext()) { |
| vectorPtr = new llvm::GlobalVariable(*IGM.getModule(), |
| metadataArrayPtrTy, |
| /*constant*/ false, |
| llvm::GlobalValue::PrivateLinkage, |
| nullVector, |
| llvm::Twine("field_type_vector_") |
| + type->getName().str()); |
| // For a generic type, use a slot we saved in the generic metadata pattern |
| // immediately after the metadata object itself, which should be |
| // instantiated with every generic metadata instance. |
| } else { |
| auto size = IGM.getMetadataLayout(type).getSize(); |
| Size offset = size.getOffsetToEnd(); |
| vectorPtr = IGF.Builder.CreateBitCast(metadata, |
| metadataArrayPtrTy->getPointerTo()); |
| vectorPtr = IGF.Builder.CreateConstInBoundsGEP1_32( |
| /*Ty=*/nullptr, vectorPtr, IGM.getOffsetInWords(offset)); |
| } |
| |
| // First, see if the field type vector has already been populated. This |
| // load can be nonatomic; if we race to build the field offset vector, we |
| // will detect so when we try to commit our pointer and simply discard the |
| // redundant work. |
| llvm::Value *initialVector |
| = IGF.Builder.CreateLoad(vectorPtr, IGM.getPointerAlignment()); |
| |
| auto entryBB = IGF.Builder.GetInsertBlock(); |
| auto buildBB = IGF.createBasicBlock("build_field_types"); |
| auto raceLostBB = IGF.createBasicBlock("race_lost"); |
| auto doneBB = IGF.createBasicBlock("done"); |
| |
| llvm::Value *isNull |
| = IGF.Builder.CreateICmpEQ(initialVector, nullVector); |
| IGF.Builder.CreateCondBr(isNull, buildBB, doneBB); |
| |
| // Build the field type vector if we didn't already. |
| IGF.Builder.emitBlock(buildBB); |
| |
| // Bind the metadata instance to our local type data so we |
| // use it to provide metadata for generic parameters in field types. |
| IGF.bindLocalTypeDataFromTypeMetadata(formalType, IsExact, metadata); |
| |
| // Allocate storage for the field vector. |
| unsigned allocSize = fieldTypes.size() * IGM.getPointerSize().getValue(); |
| auto allocSizeVal = llvm::ConstantInt::get(IGM.IntPtrTy, allocSize); |
| auto allocAlignMaskVal = |
| IGM.getSize(IGM.getPointerAlignment().asSize() - Size(1)); |
| llvm::Value *builtVectorAlloc |
| = IGF.emitAllocRawCall(allocSizeVal, allocAlignMaskVal); |
| |
| llvm::Value *builtVector |
| = IGF.Builder.CreateBitCast(builtVectorAlloc, metadataArrayPtrTy); |
| |
| // Emit type metadata for the fields into the vector. |
| for (unsigned i : indices(fieldTypes)) { |
| auto fieldTy = fieldTypes[i].getType(); |
| auto slot = IGF.Builder.CreateInBoundsGEP(builtVector, |
| llvm::ConstantInt::get(IGM.Int32Ty, i)); |
| |
| // Strip reference storage qualifiers like unowned and weak. |
| // FIXME: Some clients probably care about them. |
| if (auto refStorTy = dyn_cast<ReferenceStorageType>(fieldTy)) |
| fieldTy = refStorTy.getReferentType(); |
| |
| auto metadata = IGF.emitTypeMetadataRef(fieldTy); |
| |
| auto fieldTypeInfo = fieldTypes[i]; |
| |
| // Mix in flag bits. |
| if (fieldTypeInfo.hasFlags()) { |
| auto flags = FieldType() |
| .withIndirect(fieldTypeInfo.isIndirect()) |
| .withWeak(fieldTypeInfo.isWeak()); |
| auto metadataBits = IGF.Builder.CreatePtrToInt(metadata, IGF.IGM.SizeTy); |
| metadataBits = IGF.Builder.CreateOr(metadataBits, |
| llvm::ConstantInt::get(IGF.IGM.SizeTy, flags.getIntValue())); |
| metadata = IGF.Builder.CreateIntToPtr(metadataBits, metadata->getType()); |
| } |
| |
| IGF.Builder.CreateStore(metadata, slot, IGM.getPointerAlignment()); |
| } |
| |
| // Atomically compare-exchange a pointer to our vector into the slot. |
| auto vectorIntPtr = IGF.Builder.CreateBitCast(vectorPtr, |
| IGM.IntPtrTy->getPointerTo()); |
| auto builtVectorInt = IGF.Builder.CreatePtrToInt(builtVector, |
| IGM.IntPtrTy); |
| auto zero = llvm::ConstantInt::get(IGM.IntPtrTy, 0); |
| |
| llvm::Value *raceVectorInt = IGF.Builder.CreateAtomicCmpXchg(vectorIntPtr, |
| zero, builtVectorInt, |
| llvm::AtomicOrdering::SequentiallyConsistent, |
| llvm::AtomicOrdering::SequentiallyConsistent); |
| |
| // We might have added internal control flow above. |
| buildBB = IGF.Builder.GetInsertBlock(); |
| |
| // The pointer in the slot should still have been null. |
| auto didStore = IGF.Builder.CreateExtractValue(raceVectorInt, 1); |
| raceVectorInt = IGF.Builder.CreateExtractValue(raceVectorInt, 0); |
| IGF.Builder.CreateCondBr(didStore, doneBB, raceLostBB); |
| |
| // If the cmpxchg failed, someone beat us to landing their field type |
| // vector. Deallocate ours and return the winner. |
| IGF.Builder.emitBlock(raceLostBB); |
| IGF.emitDeallocRawCall(builtVectorAlloc, allocSizeVal, allocAlignMaskVal); |
| auto raceVector = IGF.Builder.CreateIntToPtr(raceVectorInt, |
| metadataArrayPtrTy); |
| IGF.Builder.CreateBr(doneBB); |
| |
| // Return the result. |
| IGF.Builder.emitBlock(doneBB); |
| auto phi = IGF.Builder.CreatePHI(metadataArrayPtrTy, 3); |
| phi->addIncoming(initialVector, entryBB); |
| phi->addIncoming(builtVector, buildBB); |
| phi->addIncoming(raceVector, raceLostBB); |
| |
| IGF.Builder.CreateRet(phi); |
| } |
| |
| /*****************************************************************************/ |
| /** Metadata Emission ********************************************************/ |
| /*****************************************************************************/ |
| |
| namespace { |
| /// An adapter class which turns a metadata layout class into a |
| /// generic metadata layout class. |
| template <class Impl, class Base> |
| class GenericMetadataBuilderBase : public Base { |
| typedef Base super; |
| |
| /// The number of generic witnesses in the type we're emitting. |
| /// This is not really something we need to track. |
| unsigned NumGenericWitnesses = 0; |
| |
| struct FillOp { |
| CanType Type; |
| Optional<ProtocolConformanceRef> Conformance; |
| Size ToOffset; |
| bool IsRelative; |
| }; |
| |
| SmallVector<FillOp, 8> FillOps; |
| |
| enum { TemplateHeaderFieldCount = 5 }; |
| enum { NumPrivateDataWords = swift::NumGenericMetadataPrivateDataWords }; |
| |
| protected: |
| Size TemplateHeaderSize; |
| |
| /// The offset of the address point in the type we're emitting. |
| Size AddressPoint = Size::invalid(); |
| |
| IRGenModule &IGM = super::IGM; |
| using super::asImpl; |
| using super::Target; |
| using super::B; |
| |
| /// Set to true if the metadata record for the generic type has fields |
| /// outside of the generic parameter vector. |
| bool HasDependentMetadata = false; |
| |
| /// Set to true if the value witness table for the generic type is dependent |
| /// on its generic parameters. If true, the value witness will be |
| /// tail-emplaced inside the metadata pattern and initialized by the fill |
| /// function. Implies HasDependentMetadata. |
| bool HasDependentVWT = false; |
| |
| /// The offset of the tail-allocated dependent VWT, if any. |
| Size DependentVWTPoint = Size::invalid(); |
| |
| template <class... T> |
| GenericMetadataBuilderBase(IRGenModule &IGM, T &&...args) |
| : super(IGM, std::forward<T>(args)...) {} |
| |
| /// Emit the create function for the template. |
| llvm::Function *emitCreateFunction() { |
| // Metadata *(*CreateFunction)(GenericMetadata*, const void * const *) |
| llvm::Type *argTys[] = {IGM.TypeMetadataPatternPtrTy, IGM.Int8PtrPtrTy}; |
| auto ty = llvm::FunctionType::get(IGM.TypeMetadataPtrTy, |
| argTys, /*isVarArg*/ false); |
| llvm::Function *f = llvm::Function::Create(ty, |
| llvm::GlobalValue::PrivateLinkage, |
| llvm::Twine("create_generic_metadata_") |
| + Target->getName().str(), |
| &IGM.Module); |
| f->setAttributes(IGM.constructInitialAttributes()); |
| |
| IRGenFunction IGF(IGM, f); |
| |
| // Skip instrumentation when building for TSan to avoid false positives. |
| // The synchronization for this happens in the Runtime and we do not see it. |
| if (IGM.IRGen.Opts.Sanitizers & SanitizerKind::Thread) |
| f->removeFnAttr(llvm::Attribute::SanitizeThread); |
| |
| if (IGM.DebugInfo) |
| IGM.DebugInfo->emitArtificialFunction(IGF, f); |
| |
| Explosion params = IGF.collectParameters(); |
| llvm::Value *metadataPattern = params.claimNext(); |
| llvm::Value *args = params.claimNext(); |
| |
| // Bind the generic arguments. |
| if (Target->isGenericContext()) { |
| Address argsArray(args, IGM.getPointerAlignment()); |
| emitPolymorphicParametersFromArray(IGF, Target, argsArray); |
| } |
| |
| // Allocate the metadata. |
| llvm::Value *metadataValue = |
| asImpl().emitAllocateMetadata(IGF, metadataPattern, args); |
| |
| // Execute the fill ops. Cast the parameters to word pointers because the |
| // fill indexes are word-indexed. |
| Address metadataWords(IGF.Builder.CreateBitCast(metadataValue, IGM.Int8PtrPtrTy), |
| IGM.getPointerAlignment()); |
| |
| for (auto &fillOp : FillOps) { |
| llvm::Value *value; |
| if (fillOp.Conformance) { |
| value = emitWitnessTableRef(IGF, fillOp.Type, *fillOp.Conformance); |
| } else { |
| value = IGF.emitTypeMetadataRef(fillOp.Type); |
| } |
| |
| auto dest = createPointerSizedGEP(IGF, metadataWords, |
| fillOp.ToOffset - AddressPoint); |
| |
| // A far relative indirectable pointer. |
| if (fillOp.IsRelative) { |
| dest = IGF.Builder.CreateElementBitCast(dest, |
| IGM.FarRelativeAddressTy); |
| IGF.emitStoreOfRelativeIndirectablePointer(value, dest, |
| /*isFar*/ true); |
| |
| // A direct pointer. |
| } else { |
| value = IGF.Builder.CreateBitCast(value, IGM.Int8PtrTy); |
| IGF.Builder.CreateStore(value, dest); |
| } |
| } |
| |
| // Initialize the instantiated dependent value witness table, if we have |
| // one. |
| llvm::Value *vwtableValue = nullptr; |
| if (HasDependentVWT) { |
| assert(!AddressPoint.isInvalid() && "did not set valid address point!"); |
| assert(!DependentVWTPoint.isInvalid() && "did not set dependent VWT point!"); |
| |
| // Fill in the pointer from the metadata to the VWT. The VWT pointer |
| // always immediately precedes the address point. |
| auto vwtAddr = createPointerSizedGEP(IGF, metadataWords, |
| DependentVWTPoint - AddressPoint); |
| vwtableValue = IGF.Builder.CreateBitCast(vwtAddr.getAddress(), |
| IGF.IGM.WitnessTablePtrTy); |
| |
| auto vwtAddrVal = IGF.Builder.CreateBitCast(vwtableValue, IGM.Int8PtrTy); |
| auto vwtRefAddr = createPointerSizedGEP(IGF, metadataWords, |
| Size(0) - IGM.getPointerSize()); |
| IGF.Builder.CreateStore(vwtAddrVal, vwtRefAddr); |
| |
| HasDependentMetadata = true; |
| } |
| |
| if (HasDependentMetadata) { |
| asImpl().emitInitializeMetadata(IGF, metadataValue, vwtableValue); |
| } |
| |
| // The metadata is now complete. |
| IGF.Builder.CreateRet(metadataValue); |
| |
| return f; |
| } |
| |
| void addFillOp(CanType type, Optional<ProtocolConformanceRef> conf, |
| bool isRelative) { |
| FillOps.push_back({type, conf, getNextOffsetFromTemplateHeader(), |
| isRelative }); |
| } |
| |
| public: |
| void createMetadataAccessFunction() { |
| (void) getGenericTypeMetadataAccessFunction(IGM, Target, ForDefinition); |
| } |
| |
| void layout() { |
| TemplateHeaderSize = |
| ((NumPrivateDataWords + 1) * IGM.getPointerSize()) + Size(8); |
| |
| auto privateDataInit = getPrivateDataInit(); |
| |
| // Leave room for the header. |
| auto createFunctionField = B.addPlaceholderWithSize(IGM.Int8PtrTy); |
| auto sizeField = B.addPlaceholderWithSize(IGM.Int32Ty); |
| auto numArgumentsField = B.addPlaceholderWithSize(IGM.Int16Ty); |
| auto addressPointField = B.addPlaceholderWithSize(IGM.Int16Ty); |
| auto privateDataField = |
| B.addPlaceholderWithSize(privateDataInit->getType()); |
| |
| // Lay out the template data. |
| super::layout(); |
| |
| // Save a slot for the field type vector address to be instantiated into. |
| asImpl().addFieldTypeVectorReferenceSlot(); |
| |
| // If we have a dependent value witness table, emit its template. |
| if (HasDependentVWT) { |
| // Note the dependent VWT offset. |
| DependentVWTPoint = getNextOffsetFromTemplateHeader(); |
| asImpl().addDependentValueWitnessTablePattern(); |
| } |
| |
| asImpl().addDependentData(); |
| |
| // Fill in the header: |
| |
| // Metadata *(*CreateFunction)(GenericMetadata *, const void*); |
| B.fillPlaceholder(createFunctionField, emitCreateFunction()); |
| |
| // uint32_t MetadataSize; |
| // We compute this assuming that every entry in the metadata table |
| // is a pointer in size. |
| Size size = getNextOffsetFromTemplateHeader(); |
| B.fillPlaceholderWithInt(sizeField, IGM.Int32Ty, size.getValue()); |
| |
| // uint16_t NumArguments; |
| // TODO: ultimately, this should be the number of actual template |
| // arguments, not the number of witness tables required. |
| unsigned numGenericArguments = |
| GenericArguments::getNumGenericArguments(IGM, Target); |
| B.fillPlaceholderWithInt(numArgumentsField, |
| IGM.Int16Ty, numGenericArguments); |
| |
| // uint16_t AddressPoint; |
| assert(!AddressPoint.isInvalid() && "address point not noted!"); |
| B.fillPlaceholderWithInt(addressPointField, |
| IGM.Int16Ty, AddressPoint.getValue()); |
| |
| // void *PrivateData[NumPrivateDataWords]; |
| B.fillPlaceholder(privateDataField, privateDataInit); |
| } |
| |
| /// Write down the index of the address point. |
| void noteAddressPoint() { |
| AddressPoint = getNextOffsetFromTemplateHeader(); |
| super::noteAddressPoint(); |
| } |
| |
| /// Ignore the preallocated header. |
| Size getNextOffsetFromTemplateHeader() const { |
| // Note that the header fields are all pointer-sized. |
| return B.getNextOffsetFromGlobal() - TemplateHeaderSize; |
| } |
| |
| /// Ignore the destructor and value witness table. |
| Size getNextOffsetFromAddressPoint() const { |
| return getNextOffsetFromTemplateHeader() - AddressPoint; |
| } |
| |
| template <class... T> |
| void addGenericArgument(CanType type, T &&...args) { |
| NumGenericWitnesses++; |
| addFillOp(type, None, /*relative*/ false); |
| super::addGenericArgument(type, std::forward<T>(args)...); |
| } |
| |
| template <class... T> |
| void addGenericWitnessTable(CanType type, ProtocolConformanceRef conf, |
| T &&...args) { |
| NumGenericWitnesses++; |
| addFillOp(type, conf, /*relative*/ false); |
| super::addGenericWitnessTable(type, conf, std::forward<T>(args)...); |
| } |
| |
| void addFieldTypeVectorReferenceSlot() { |
| B.addNullPointer(IGM.TypeMetadataPtrTy->getPointerTo()); |
| } |
| |
| // Can be overridden by subclassers to emit other dependent metadata. |
| void addDependentData() {} |
| |
| private: |
| static llvm::Constant *makeArray(llvm::Type *eltTy, |
| ArrayRef<llvm::Constant*> elts) { |
| auto arrayTy = llvm::ArrayType::get(eltTy, elts.size()); |
| return llvm::ConstantArray::get(arrayTy, elts); |
| } |
| |
| /// Produce the initializer for the private-data field of the |
| /// template header. |
| llvm::Constant *getPrivateDataInit() { |
| auto null = llvm::ConstantPointerNull::get(IGM.Int8PtrTy); |
| |
| llvm::Constant *privateData[NumPrivateDataWords]; |
| |
| for (auto &element : privateData) |
| element = null; |
| |
| return makeArray(IGM.Int8PtrTy, privateData); |
| } |
| }; |
| } // end anonymous namespace |
| |
| llvm::Value * |
| irgen::emitInitializeFieldOffsetVector(IRGenFunction &IGF, |
| SILType T, |
| llvm::Value *metadata, |
| llvm::Value *vwtable) { |
| auto *target = T.getNominalOrBoundGenericNominal(); |
| llvm::Value *fieldVector |
| = emitAddressOfFieldOffsetVector(IGF, metadata, target) |
| .getAddress(); |
| |
| // Collect the stored properties of the type. |
| llvm::SmallVector<VarDecl*, 4> storedProperties; |
| for (auto prop : target->getStoredProperties()) { |
| storedProperties.push_back(prop); |
| } |
| |
| // Fill out an array with the field type metadata records. |
| Address fields = IGF.createAlloca( |
| llvm::ArrayType::get(IGF.IGM.Int8PtrPtrTy, |
| storedProperties.size()), |
| IGF.IGM.getPointerAlignment(), "classFields"); |
| IGF.Builder.CreateLifetimeStart(fields, |
| IGF.IGM.getPointerSize() * storedProperties.size()); |
| fields = IGF.Builder.CreateStructGEP(fields, 0, Size(0)); |
| |
| unsigned index = 0; |
| for (auto prop : storedProperties) { |
| auto propTy = T.getFieldType(prop, IGF.getSILModule()); |
| llvm::Value *metadata = IGF.emitTypeLayoutRef(propTy); |
| Address field = IGF.Builder.CreateConstArrayGEP(fields, index, |
| IGF.IGM.getPointerSize()); |
| IGF.Builder.CreateStore(metadata, field); |
| ++index; |
| } |
| |
| // Ask the runtime to lay out the class. This can relocate it if it |
| // wasn't allocated with swift_allocateGenericClassMetadata. |
| auto numFields = IGF.IGM.getSize(Size(storedProperties.size())); |
| |
| if (isa<ClassDecl>(target)) { |
| assert(vwtable == nullptr); |
| metadata = IGF.Builder.CreateCall(IGF.IGM.getInitClassMetadataUniversalFn(), |
| {metadata, numFields, |
| fields.getAddress(), fieldVector}); |
| } else { |
| assert(isa<StructDecl>(target)); |
| IGF.Builder.CreateCall(IGF.IGM.getInitStructMetadataUniversalFn(), |
| {numFields, fields.getAddress(), |
| fieldVector, vwtable}); |
| } |
| |
| IGF.Builder.CreateLifetimeEnd(fields, |
| IGF.IGM.getPointerSize() * storedProperties.size()); |
| |
| return metadata; |
| } |
| |
| // Classes |
| |
| namespace { |
| /// An adapter for laying out class metadata. |
| template <class Impl> |
| class ClassMetadataBuilderBase : public ClassMetadataVisitor<Impl> { |
| using super = ClassMetadataVisitor<Impl>; |
| |
| protected: |
| using super::IGM; |
| using super::Target; |
| using super::asImpl; |
| |
| ConstantStructBuilder &B; |
| const StructLayout &Layout; |
| const ClassLayout &FieldLayout; |
| SILVTable *VTable; |
| |
| struct MethodOverride { |
| Size Offset; |
| SILFunction *Method; |
| }; |
| |
| SmallVector<MethodOverride, 4> Overrides; |
| |
| ClassMetadataBuilderBase(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : super(IGM, theClass), B(builder), |
| Layout(layout), FieldLayout(fieldLayout) { |
| VTable = IGM.getSILModule().lookUpVTable(Target); |
| } |
| |
| public: |
| /// The 'metadata flags' field in a class is actually a pointer to |
| /// the metaclass object for the class. |
| /// |
| /// NONAPPLE: This is only really required for ObjC interop; maybe |
| /// suppress this for classes that don't need to be exposed to |
| /// ObjC, e.g. for non-Apple platforms? |
| void addMetadataFlags() { |
| static_assert(unsigned(MetadataKind::Class) == 0, |
| "class metadata kind is non-zero?"); |
| |
| if (IGM.ObjCInterop) { |
| // Get the metaclass pointer as an intptr_t. |
| auto metaclass = IGM.getAddrOfMetaclassObject(Target, |
| NotForDefinition); |
| auto flags = |
| llvm::ConstantExpr::getPtrToInt(metaclass, IGM.MetadataKindTy); |
| B.add(flags); |
| } else { |
| // On non-objc platforms just fill it with a null, there |
| // is no Objective-C metaclass. |
| // FIXME: Remove this to save metadata space. |
| // rdar://problem/18801263 |
| B.addInt(IGM.MetadataKindTy, unsigned(MetadataKind::Class)); |
| } |
| } |
| |
| /// The runtime provides a value witness table for Builtin.NativeObject. |
| void addValueWitnessTable() { |
| ClassDecl *cls = Target; |
| |
| auto type = (cls->checkObjCAncestry() != ObjCClassKind::NonObjC |
| ? IGM.Context.TheUnknownObjectType |
| : IGM.Context.TheNativeObjectType); |
| auto wtable = IGM.getAddrOfValueWitnessTable(type); |
| B.add(wtable); |
| } |
| |
| void addDestructorFunction() { |
| auto expansion = ResilienceExpansion::Minimal; |
| auto dtorRef = SILDeclRef(Target->getDestructor(), |
| SILDeclRef::Kind::Deallocator, |
| expansion); |
| SILFunction *dtorFunc = IGM.getSILModule().lookUpFunction(dtorRef); |
| if (dtorFunc) { |
| B.add(IGM.getAddrOfSILFunction(dtorFunc, NotForDefinition)); |
| } else { |
| // In case the optimizer removed the function. See comment in |
| // addMethod(). |
| B.addNullPointer(IGM.FunctionPtrTy); |
| } |
| } |
| |
| void addNominalTypeDescriptor() { |
| auto descriptor = ClassNominalTypeDescriptorBuilder(IGM, Target).emit(); |
| B.add(descriptor); |
| } |
| |
| void addIVarDestroyer() { |
| auto dtorFunc = IGM.getAddrOfIVarInitDestroy(Target, |
| /*isDestroyer=*/ true, |
| /*isForeign=*/ false, |
| NotForDefinition); |
| if (dtorFunc) { |
| B.add(*dtorFunc); |
| } else { |
| B.addNullPointer(IGM.FunctionPtrTy); |
| } |
| } |
| |
| bool addReferenceToHeapMetadata(CanType type, bool allowUninitialized) { |
| if (llvm::Constant *metadata |
| = tryEmitConstantHeapMetadataRef(IGM, type, allowUninitialized)) { |
| B.add(metadata); |
| return true; |
| } else { |
| // Leave a null pointer placeholder to be filled at runtime |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| return false; |
| } |
| } |
| |
| void addClassFlags() { |
| // Always set a flag saying that this is a Swift 1.0 class. |
| ClassFlags flags = ClassFlags::IsSwift1; |
| |
| // Set a flag if the class uses Swift 1.0 refcounting. |
| auto type = Target->getDeclaredType()->getCanonicalType(); |
| if (getReferenceCountingForType(IGM, type) |
| == ReferenceCounting::Native) { |
| flags |= ClassFlags::UsesSwift1Refcounting; |
| } |
| |
| DeclAttributes attrs = Target->getAttrs(); |
| if (auto objc = attrs.getAttribute<ObjCAttr>()) { |
| if (objc->getName()) |
| flags |= ClassFlags::HasCustomObjCName; |
| } |
| if (attrs.hasAttribute<ObjCRuntimeNameAttr>()) |
| flags |= ClassFlags::HasCustomObjCName; |
| |
| B.addInt32((uint32_t) flags); |
| } |
| |
| void addInstanceAddressPoint() { |
| // Right now, we never allocate fields before the address point. |
| B.addInt32(0); |
| } |
| |
| void addInstanceSize() { |
| if (llvm::Constant *size |
| = tryEmitClassConstantFragileInstanceSize(IGM, Target)) { |
| // We only support a maximum 32-bit instance size. |
| if (IGM.SizeTy != IGM.Int32Ty) |
| size = llvm::ConstantExpr::getTrunc(size, IGM.Int32Ty); |
| B.add(size); |
| } else { |
| // Leave a zero placeholder to be filled at runtime |
| B.addInt32(0); |
| } |
| } |
| |
| void addInstanceAlignMask() { |
| if (llvm::Constant *align |
| = tryEmitClassConstantFragileInstanceAlignMask(IGM, Target)) { |
| if (IGM.SizeTy != IGM.Int16Ty) |
| align = llvm::ConstantExpr::getTrunc(align, IGM.Int16Ty); |
| B.add(align); |
| } else { |
| // Leave a zero placeholder to be filled at runtime |
| B.addInt16(0); |
| } |
| } |
| |
| void addRuntimeReservedBits() { |
| B.addInt16(0); |
| } |
| |
| void addClassSize() { |
| auto size = IGM.getMetadataLayout(Target).getSize(); |
| B.addInt32(size.FullSize.getValue()); |
| } |
| |
| void addClassAddressPoint() { |
| auto size = IGM.getMetadataLayout(Target).getSize(); |
| B.addInt32(size.AddressPoint.getValue()); |
| } |
| |
| void addClassCacheData() { |
| // We initially fill in these fields with addresses taken from |
| // the ObjC runtime. |
| // FIXME: Remove null data altogether rdar://problem/18801263 |
| B.add(IGM.getObjCEmptyCachePtr()); |
| B.add(IGM.getObjCEmptyVTablePtr()); |
| } |
| |
| void addClassDataPointer() { |
| if (!IGM.ObjCInterop) { |
| // with no Objective-C runtime, just give an empty pointer with the |
| // swift bit set. |
| B.addInt(IGM.IntPtrTy, 1); |
| return; |
| } |
| // Derive the RO-data. |
| llvm::Constant *data = emitClassPrivateData(IGM, Target); |
| |
| // We always set the low bit to indicate this is a Swift class. |
| data = llvm::ConstantExpr::getPtrToInt(data, IGM.IntPtrTy); |
| data = llvm::ConstantExpr::getAdd(data, |
| llvm::ConstantInt::get(IGM.IntPtrTy, 1)); |
| |
| B.add(data); |
| } |
| |
| void addFieldOffset(VarDecl *var) { |
| assert(var->hasStorage()); |
| |
| unsigned fieldIndex = FieldLayout.getFieldIndex(var); |
| llvm::Constant *fieldOffsetOrZero; |
| auto &element = Layout.getElement(fieldIndex); |
| |
| if (element.getKind() == ElementLayout::Kind::Fixed) { |
| // Use a fixed offset if we have one. |
| fieldOffsetOrZero = IGM.getSize(element.getByteOffset()); |
| } else { |
| // Otherwise, leave a placeholder for the runtime to populate at runtime. |
| fieldOffsetOrZero = IGM.getSize(Size(0)); |
| } |
| B.add(fieldOffsetOrZero); |
| |
| if (var->getDeclContext() == Target) { |
| auto access = FieldLayout.AllFieldAccesses[fieldIndex]; |
| switch (access) { |
| case FieldAccess::ConstantDirect: |
| case FieldAccess::NonConstantDirect: { |
| // Emit a global variable storing the constant field offset. |
| // If the superclass was imported from Objective-C, the offset |
| // does not include the superclass size; we rely on the |
| // Objective-C runtime sliding it down. |
| // |
| // TODO: Don't emit the symbol if field has a fixed offset and size |
| // in all resilience domains |
| auto offsetAddr = IGM.getAddrOfFieldOffset(var, /*indirect*/ false, |
| ForDefinition); |
| auto offsetVar = cast<llvm::GlobalVariable>(offsetAddr.getAddress()); |
| offsetVar->setInitializer(fieldOffsetOrZero); |
| |
| // If we know the offset won't change, make it a constant. |
| offsetVar->setConstant(access == FieldAccess::ConstantDirect); |
| |
| break; |
| } |
| |
| case FieldAccess::ConstantIndirect: |
| // No global variable is needed. |
| break; |
| |
| case FieldAccess::NonConstantIndirect: |
| // Emit a global variable storing an offset into the field offset |
| // vector within the class metadata. This access pattern is used |
| // when the field offset depends on generic parameters. As above, |
| // the Objective-C runtime will slide the field offsets within the |
| // class metadata to adjust for the superclass size. |
| // |
| // TODO: This isn't plumbed through all the way yet. |
| auto offsetAddr = IGM.getAddrOfFieldOffset(var, /*indirect*/ true, |
| ForDefinition); |
| auto offsetVar = cast<llvm::GlobalVariable>(offsetAddr.getAddress()); |
| offsetVar->setConstant(false); |
| auto offset = getClassFieldOffsetOffset(IGM, Target, var).getValue(); |
| auto offsetVal = llvm::ConstantInt::get(IGM.IntPtrTy, offset); |
| offsetVar->setInitializer(offsetVal); |
| |
| break; |
| } |
| } |
| } |
| |
| void addFieldOffsetPlaceholders(MissingMemberDecl *placeholder) { |
| for (unsigned i = 0, |
| e = placeholder->getNumberOfFieldOffsetVectorEntries(); |
| i < e; ++i) { |
| // Emit placeholder values for some number of stored properties we |
| // know exist but aren't able to reference directly. |
| B.addInt(IGM.SizeTy, 0); |
| } |
| } |
| |
| void addMethod(SILDeclRef fn) { |
| // Find the vtable entry. |
| assert(VTable && "no vtable?!"); |
| auto entry = VTable->getEntry(IGM.getSILModule(), fn); |
| |
| // If the class is resilient or generic, the runtime will construct the |
| // vtable for us. All we need to do is fix up overrides of superclass |
| // methods. |
| if (doesClassMetadataRequireDynamicInitialization(IGM, Target)) { |
| if (entry && entry->TheKind == SILVTable::Entry::Kind::Override) { |
| // Record the override so that we can fill it in later. |
| Overrides.push_back({asImpl().getNextOffsetFromAddressPoint(), |
| entry->Implementation}); |
| } |
| |
| B.addNullPointer(IGM.FunctionPtrTy); |
| return; |
| } |
| |
| // The class is fragile. Emit a direct reference to the vtable entry. |
| if (entry) { |
| B.add(IGM.getAddrOfSILFunction(entry->Implementation, NotForDefinition)); |
| return; |
| } |
| |
| // The method is removed by dead method elimination. |
| // It should be never called. We add a pointer to an error function. |
| B.addBitCast(IGM.getDeletedMethodErrorFn(), IGM.FunctionPtrTy); |
| } |
| |
| void addPlaceholder(MissingMemberDecl *m) { |
| assert(m->getNumberOfVTableEntries() == 0 |
| && "cannot generate metadata with placeholders in it"); |
| } |
| |
| void addMethodOverride(SILDeclRef baseRef, SILDeclRef declRef) {} |
| |
| void addGenericArgument(CanType argTy, ClassDecl *forClass) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addGenericWitnessTable(CanType argTy, ProtocolConformanceRef conf, |
| ClassDecl *forClass) { |
| B.addNullPointer(IGM.WitnessTablePtrTy); |
| } |
| |
| protected: |
| bool isFinishInitializationIdempotent() { |
| if (!Layout.isFixedLayout()) |
| return false; |
| |
| if (doesClassMetadataRequireDynamicInitialization(IGM, Target)) |
| return false; |
| |
| return true; |
| } |
| |
| llvm::Value *emitFinishIdempotentInitialization(IRGenFunction &IGF, |
| llvm::Value *metadata) { |
| if (IGF.IGM.ObjCInterop) { |
| metadata = |
| IGF.Builder.CreateBitCast(metadata, IGF.IGM.ObjCClassPtrTy); |
| metadata = |
| IGF.Builder.CreateCall(IGF.IGM.getGetInitializedObjCClassFn(), |
| metadata); |
| metadata = |
| IGF.Builder.CreateBitCast(metadata, IGF.IGM.TypeMetadataPtrTy); |
| } |
| return metadata; |
| } |
| |
| llvm::Value *emitFinishInitializationOfClassMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata) { |
| // We assume that we've already filled in the class's generic arguments. |
| // We need to: |
| // - relocate the metadata to accommodate the superclass, |
| // if something in our hierarchy is resilient to us; |
| // - fill out the subclass's field offset vector, if its layout |
| // wasn't fixed; |
| // - copy field offsets and generic arguments from higher in the |
| // class hierarchy, if |
| // - copy the superclass data, if there are generic arguments |
| // or field offset vectors there that weren't filled in; |
| // - populate the field offset vector, if layout isn't fixed, and |
| // - register the class with the ObjC runtime, if ObjC interop is |
| // enabled. |
| // |
| // emitInitializeFieldOffsetVector will do everything in the full case. |
| if (doesClassMetadataRequireDynamicInitialization(IGF.IGM, Target)) { |
| auto classTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| auto loweredClassTy = IGF.IGM.getLoweredType(classTy); |
| metadata = emitInitializeFieldOffsetVector(IGF, loweredClassTy, |
| metadata, |
| /*vwtable=*/nullptr); |
| |
| // TODO: do something intermediate when e.g. all we needed to do was |
| // set parent metadata pointers. |
| |
| // Otherwise, all we need to do is register with the ObjC runtime. |
| } else { |
| metadata = emitFinishIdempotentInitialization(IGF, metadata); |
| assert(Overrides.empty()); |
| } |
| |
| emitInitializeMethodOverrides(IGF, metadata); |
| |
| // Realizing the class with the ObjC runtime will copy back to the |
| // field offset globals for us; but if ObjC interop is disabled, we |
| // have to do that ourselves, assuming we didn't just emit them all |
| // correctly in the first place. |
| if (!Layout.isFixedLayout() && !IGF.IGM.ObjCInterop) |
| emitInitializeFieldOffsets(IGF, metadata); |
| |
| return metadata; |
| } |
| |
| // Update vtable entries for method overrides. The runtime copies in |
| // the vtable from the superclass for us; we have to install method |
| // overrides ourselves. |
| void emitInitializeMethodOverrides(IRGenFunction &IGF, |
| llvm::Value *metadata) { |
| if (Overrides.empty()) |
| return; |
| |
| Address metadataWords( |
| IGF.Builder.CreateBitCast(metadata, IGM.Int8PtrPtrTy), |
| IGM.getPointerAlignment()); |
| |
| for (auto Override : Overrides) { |
| auto *implFn = IGM.getAddrOfSILFunction(Override.Method, |
| NotForDefinition); |
| |
| auto dest = createPointerSizedGEP(IGF, metadataWords, |
| Override.Offset); |
| auto *value = IGF.Builder.CreateBitCast(implFn, IGM.Int8PtrTy); |
| IGF.Builder.CreateStore(value, dest); |
| } |
| } |
| |
| // The Objective-C runtime will copy field offsets from the field offset |
| // vector into field offset globals for us, if present. If there's no |
| // Objective-C runtime, we have to do this ourselves. |
| void emitInitializeFieldOffsets(IRGenFunction &IGF, |
| llvm::Value *metadata) { |
| unsigned index = FieldLayout.InheritedStoredProperties.size(); |
| |
| for (auto prop : Target->getStoredProperties()) { |
| auto access = FieldLayout.AllFieldAccesses[index]; |
| if (access == FieldAccess::NonConstantDirect) { |
| Address offsetA = IGF.IGM.getAddrOfFieldOffset(prop, |
| /*indirect*/ false, |
| ForDefinition); |
| |
| // We can't use emitClassFieldOffset() here because that creates |
| // an invariant load, which could be hoisted above the point |
| // where the metadata becomes fully initialized |
| auto slot = |
| emitAddressOfClassFieldOffset(IGF, metadata, Target, prop); |
| auto offsetVal = IGF.emitInvariantLoad(slot); |
| IGF.Builder.CreateStore(offsetVal, offsetA); |
| } |
| |
| index++; |
| } |
| } |
| }; |
| |
| class ClassMetadataBuilder : |
| public ClassMetadataBuilderBase<ClassMetadataBuilder> { |
| |
| using super = ClassMetadataBuilderBase<ClassMetadataBuilder>; |
| |
| bool HasUnfilledSuperclass = false; |
| |
| Size AddressPoint; |
| |
| public: |
| ClassMetadataBuilder(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : ClassMetadataBuilderBase(IGM, theClass, builder, layout, fieldLayout) { |
| } |
| |
| void noteAddressPoint() { |
| super::noteAddressPoint(); |
| AddressPoint = B.getNextOffsetFromGlobal(); |
| } |
| |
| Size getNextOffsetFromAddressPoint() const { |
| return B.getNextOffsetFromGlobal() - AddressPoint; |
| } |
| |
| void addSuperClass() { |
| // If this is a root class, use SwiftObject as our formal parent. |
| if (!Target->hasSuperclass()) { |
| // This is only required for ObjC interoperation. |
| if (!IGM.ObjCInterop) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| return; |
| } |
| |
| // We have to do getAddrOfObjCClass ourselves here because |
| // the ObjC runtime base needs to be ObjC-mangled but isn't |
| // actually imported from a clang module. |
| B.add(IGM.getAddrOfObjCClass( |
| IGM.getObjCRuntimeBaseForSwiftRootClass(Target), |
| NotForDefinition)); |
| return; |
| } |
| |
| Type superclassTy = Target->mapTypeIntoContext(Target->getSuperclass()); |
| |
| if (!addReferenceToHeapMetadata(superclassTy->getCanonicalType(), |
| /*allowUninit*/ false)) { |
| HasUnfilledSuperclass = true; |
| } |
| |
| // If the superclass came from another module, we may have dropped |
| // stored properties due to the Swift language version availability of |
| // their types. In these cases we can't precisely lay out the ivars in |
| // the class object at compile time so we need to do runtime layout. |
| if (classHasIncompleteLayout(IGM, |
| superclassTy->getClassOrBoundGenericClass())) { |
| HasUnfilledSuperclass = true; |
| } |
| } |
| |
| bool canBeConstant() { |
| // TODO: the metadata global can actually be constant in a very |
| // special case: it's not a pattern, ObjC interoperation isn't |
| // required, there are no class fields, and there is nothing that |
| // needs to be runtime-adjusted. |
| return false; |
| } |
| |
| void createMetadataAccessFunction() { |
| assert(!Target->isGenericContext()); |
| auto type =cast<ClassType>(Target->getDeclaredType()->getCanonicalType()); |
| |
| (void) getTypeMetadataAccessFunction(IGM, type, ForDefinition, |
| [&](IRGenFunction &IGF, llvm::Constant *cacheVar) -> llvm::Value* { |
| // There's an interesting special case where we can do the |
| // initialization idempotently and thus avoid the need for a lock. |
| if (!HasUnfilledSuperclass && |
| isFinishInitializationIdempotent()) { |
| auto type = Target->getDeclaredType()->getCanonicalType(); |
| auto metadata = |
| IGF.IGM.getAddrOfTypeMetadata(type, /*pattern*/ false); |
| return emitFinishIdempotentInitialization(IGF, metadata); |
| } |
| |
| // Otherwise, use the generic path. |
| return emitInPlaceTypeMetadataAccessFunctionBody(IGF, type, cacheVar, |
| [&](IRGenFunction &IGF, llvm::Value *metadata) { |
| return emitInPlaceMetadataInitialization(IGF, type, metadata); |
| }); |
| }); |
| } |
| |
| private: |
| llvm::Value *emitInPlaceMetadataInitialization(IRGenFunction &IGF, |
| CanClassType type, |
| llvm::Value *metadata) { |
| // Many of the things done by generic instantiation are unnecessary here: |
| // initializing the metaclass pointer |
| // initializing the ro-data pointer |
| |
| // Initialize the superclass if we didn't do so as a constant. |
| if (HasUnfilledSuperclass) { |
| auto superclass = type->getSuperclass()->getCanonicalType(); |
| llvm::Value *superclassMetadata = |
| emitClassHeapMetadataRef(IGF, superclass, |
| MetadataValueType::TypeMetadata, |
| /*allowUninit*/ false); |
| Address superField = |
| emitAddressOfSuperclassRefInClassMetadata(IGF, metadata); |
| superField = IGF.Builder.CreateElementBitCast(superField, |
| IGF.IGM.TypeMetadataPtrTy); |
| IGF.Builder.CreateStore(superclassMetadata, superField); |
| } |
| |
| metadata = emitFinishInitializationOfClassMetadata(IGF, metadata); |
| |
| return metadata; |
| } |
| }; |
| |
| /// A builder for metadata templates. |
| class GenericClassMetadataBuilder : |
| public GenericMetadataBuilderBase<GenericClassMetadataBuilder, |
| ClassMetadataBuilderBase<GenericClassMetadataBuilder>> |
| { |
| typedef GenericMetadataBuilderBase super; |
| |
| Size MetaclassPtrOffset = Size::invalid(); |
| Size ClassRODataPtrOffset = Size::invalid(); |
| Size MetaclassRODataPtrOffset = Size::invalid(); |
| Size DependentMetaclassPoint = Size::invalid(); |
| Size DependentClassRODataPoint = Size::invalid(); |
| Size DependentMetaclassRODataPoint = Size::invalid(); |
| public: |
| GenericClassMetadataBuilder(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &B, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : super(IGM, theClass, B, layout, fieldLayout) |
| { |
| // We need special initialization of metadata objects to trick the ObjC |
| // runtime into initializing them. |
| HasDependentMetadata = true; |
| } |
| |
| void addSuperClass() { |
| // Filled in by the runtime. |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| llvm::Value *emitAllocateMetadata(IRGenFunction &IGF, |
| llvm::Value *metadataPattern, |
| llvm::Value *arguments) { |
| llvm::Value *superMetadata; |
| if (Target->hasSuperclass()) { |
| Type superclass = Target->getSuperclass(); |
| superclass = Target->mapTypeIntoContext(superclass); |
| superMetadata = |
| emitClassHeapMetadataRef(IGF, superclass->getCanonicalType(), |
| MetadataValueType::ObjCClass); |
| } else if (IGM.ObjCInterop) { |
| superMetadata = emitObjCHeapMetadataRef(IGF, |
| IGM.getObjCRuntimeBaseForSwiftRootClass(Target)); |
| } else { |
| superMetadata |
| = llvm::ConstantPointerNull::get(IGF.IGM.ObjCClassPtrTy); |
| } |
| |
| return IGF.Builder.CreateCall(IGM.getAllocateGenericClassMetadataFn(), |
| {metadataPattern, arguments, superMetadata}); |
| } |
| |
| void addMetadataFlags() { |
| // The metaclass pointer will be instantiated here. |
| MetaclassPtrOffset = getNextOffsetFromTemplateHeader(); |
| B.addInt(IGM.MetadataKindTy, 0); |
| } |
| |
| void addClassDataPointer() { |
| // The rodata pointer will be instantiated here. |
| // Make sure we at least set the 'is Swift class' bit, though. |
| ClassRODataPtrOffset = getNextOffsetFromTemplateHeader(); |
| B.addInt(IGM.MetadataKindTy, 1); |
| } |
| |
| void addDependentData() { |
| if (!IGM.ObjCInterop) { |
| // Every piece of data in the dependent data appears to be related to |
| // Objective-C information. If we're not doing Objective-C interop, we |
| // can just skip adding it to the class. |
| return; |
| } |
| // Emit space for the dependent metaclass. |
| DependentMetaclassPoint = getNextOffsetFromTemplateHeader(); |
| // isa |
| ClassDecl *rootClass = getRootClassForMetaclass(IGM, Target); |
| auto isa = IGM.getAddrOfMetaclassObject(rootClass, NotForDefinition); |
| B.add(isa); |
| // super, which is dependent if the superclass is generic |
| B.addNullPointer(IGM.ObjCClassPtrTy); |
| // cache |
| B.add(IGM.getObjCEmptyCachePtr()); |
| // vtable |
| B.add(IGM.getObjCEmptyVTablePtr()); |
| // rodata, which is always dependent |
| MetaclassRODataPtrOffset = getNextOffsetFromTemplateHeader(); |
| B.addInt(IGM.IntPtrTy, 0); |
| |
| std::tie(DependentClassRODataPoint, DependentMetaclassRODataPoint) |
| = emitClassPrivateDataFields(IGM, B, Target); |
| DependentClassRODataPoint -= TemplateHeaderSize; |
| DependentMetaclassRODataPoint -= TemplateHeaderSize; |
| } |
| |
| void addDependentValueWitnessTablePattern() { |
| llvm_unreachable("classes should never have dependent vwtables"); |
| } |
| |
| void noteStartOfFieldOffsets(ClassDecl *whichClass) { |
| HasDependentMetadata = true; |
| } |
| |
| void noteEndOfFieldOffsets(ClassDecl *whichClass) {} |
| |
| // Suppress GenericMetadataBuilderBase's default behavior of introducing |
| // fill ops for generic arguments unless they belong directly to the target |
| // class and not its ancestors. |
| |
| void addGenericArgument(CanType type, ClassDecl *forClass) { |
| if (forClass == Target) { |
| // Introduce the fill op. |
| GenericMetadataBuilderBase::addGenericArgument(type, forClass); |
| } else { |
| // Lay out the field, but don't fill it in, we will copy it from |
| // the superclass. |
| HasDependentMetadata = true; |
| ClassMetadataBuilderBase::addGenericArgument(type, forClass); |
| } |
| } |
| |
| void addGenericWitnessTable(CanType type, ProtocolConformanceRef conf, |
| ClassDecl *forClass) { |
| if (forClass == Target) { |
| // Introduce the fill op. |
| GenericMetadataBuilderBase::addGenericWitnessTable(type, conf,forClass); |
| } else { |
| // Lay out the field, but don't provide the fill op, which we'll get |
| // from the superclass. |
| HasDependentMetadata = true; |
| ClassMetadataBuilderBase::addGenericWitnessTable(type, conf, forClass); |
| } |
| } |
| |
| void emitInitializeMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| llvm::Value *vwtable) { |
| assert(!HasDependentVWT && "class should never have dependent VWT"); |
| |
| // Fill in the metaclass pointer. |
| Address metadataPtr(IGF.Builder.CreateBitCast(metadata, IGF.IGM.Int8PtrPtrTy), |
| IGF.IGM.getPointerAlignment()); |
| |
| llvm::Value *metaclass; |
| if (IGF.IGM.ObjCInterop) { |
| assert(!DependentMetaclassPoint.isInvalid()); |
| assert(!MetaclassPtrOffset.isInvalid()); |
| |
| Address metaclassPtrSlot = createPointerSizedGEP(IGF, metadataPtr, |
| MetaclassPtrOffset - AddressPoint); |
| metaclassPtrSlot = IGF.Builder.CreateBitCast(metaclassPtrSlot, |
| IGF.IGM.ObjCClassPtrTy->getPointerTo()); |
| Address metaclassRawPtr = createPointerSizedGEP(IGF, metadataPtr, |
| DependentMetaclassPoint - AddressPoint); |
| metaclass = IGF.Builder.CreateBitCast(metaclassRawPtr, |
| IGF.IGM.ObjCClassPtrTy) |
| .getAddress(); |
| IGF.Builder.CreateStore(metaclass, metaclassPtrSlot); |
| } else { |
| // FIXME: Remove altogether rather than injecting a NULL value. |
| // rdar://problem/18801263 |
| assert(!MetaclassPtrOffset.isInvalid()); |
| Address metaclassPtrSlot = createPointerSizedGEP(IGF, metadataPtr, |
| MetaclassPtrOffset - AddressPoint); |
| metaclassPtrSlot = IGF.Builder.CreateBitCast(metaclassPtrSlot, |
| IGF.IGM.ObjCClassPtrTy->getPointerTo()); |
| IGF.Builder.CreateStore( |
| llvm::ConstantPointerNull::get(IGF.IGM.ObjCClassPtrTy), |
| metaclassPtrSlot); |
| } |
| |
| // Fill in the rodata reference in the class. |
| Address classRODataPtr; |
| if (IGF.IGM.ObjCInterop) { |
| assert(!DependentClassRODataPoint.isInvalid()); |
| assert(!ClassRODataPtrOffset.isInvalid()); |
| Address rodataPtrSlot = createPointerSizedGEP(IGF, metadataPtr, |
| ClassRODataPtrOffset - AddressPoint); |
| rodataPtrSlot = IGF.Builder.CreateBitCast(rodataPtrSlot, |
| IGF.IGM.IntPtrTy->getPointerTo()); |
| |
| classRODataPtr = createPointerSizedGEP(IGF, metadataPtr, |
| DependentClassRODataPoint - AddressPoint); |
| // Set the low bit of the value to indicate "compiled by Swift". |
| llvm::Value *rodata = IGF.Builder.CreatePtrToInt( |
| classRODataPtr.getAddress(), IGF.IGM.IntPtrTy); |
| rodata = IGF.Builder.CreateOr(rodata, 1); |
| IGF.Builder.CreateStore(rodata, rodataPtrSlot); |
| } else { |
| // NOTE: Unlike other bits of the metadata that should later be removed, |
| // this one is important because things check this value's flags to |
| // determine what kind of object it is. That said, if those checks |
| // are determined to be removable, we can remove this as well per |
| // rdar://problem/18801263 |
| assert(!ClassRODataPtrOffset.isInvalid()); |
| Address rodataPtrSlot = createPointerSizedGEP(IGF, metadataPtr, |
| ClassRODataPtrOffset - AddressPoint); |
| rodataPtrSlot = IGF.Builder.CreateBitCast(rodataPtrSlot, |
| IGF.IGM.IntPtrTy->getPointerTo()); |
| |
| IGF.Builder.CreateStore(llvm::ConstantInt::get(IGF.IGM.IntPtrTy, 1), |
| rodataPtrSlot); |
| } |
| |
| // Fill in the rodata reference in the metaclass. |
| Address metaclassRODataPtr; |
| if (IGF.IGM.ObjCInterop) { |
| assert(!DependentMetaclassRODataPoint.isInvalid()); |
| assert(!MetaclassRODataPtrOffset.isInvalid()); |
| Address rodataPtrSlot = createPointerSizedGEP(IGF, metadataPtr, |
| MetaclassRODataPtrOffset - AddressPoint); |
| rodataPtrSlot = IGF.Builder.CreateBitCast(rodataPtrSlot, |
| IGF.IGM.IntPtrTy->getPointerTo()); |
| |
| metaclassRODataPtr = createPointerSizedGEP(IGF, metadataPtr, |
| DependentMetaclassRODataPoint - AddressPoint); |
| llvm::Value *rodata = IGF.Builder.CreatePtrToInt( |
| metaclassRODataPtr.getAddress(), IGF.IGM.IntPtrTy); |
| IGF.Builder.CreateStore(rodata, rodataPtrSlot); |
| } |
| |
| // We can assume that this never relocates the metadata because |
| // it should have been allocated properly for the class. |
| (void) emitFinishInitializationOfClassMetadata(IGF, metadata); |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// Emit the ObjC-compatible class symbol for a class. |
| /// Since LLVM and many system linkers do not have a notion of relative symbol |
| /// references, we emit the symbol as a global asm block. |
| static void emitObjCClassSymbol(IRGenModule &IGM, |
| ClassDecl *classDecl, |
| llvm::GlobalValue *metadata) { |
| llvm::SmallString<32> classSymbol; |
| LinkEntity::forObjCClass(classDecl).mangle(classSymbol); |
| |
| // Create the alias. |
| auto *metadataTy = cast<llvm::PointerType>(metadata->getType()); |
| |
| // Create the alias. |
| auto *alias = llvm::GlobalAlias::create(metadataTy->getElementType(), |
| metadataTy->getAddressSpace(), |
| metadata->getLinkage(), |
| classSymbol.str(), metadata, |
| IGM.getModule()); |
| alias->setVisibility(metadata->getVisibility()); |
| |
| if (IGM.useDllStorage()) |
| alias->setDLLStorageClass(metadata->getDLLStorageClass()); |
| } |
| |
| /// Emit the type metadata or metadata template for a class. |
| void irgen::emitClassMetadata(IRGenModule &IGM, ClassDecl *classDecl, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) { |
| assert(!classDecl->isForeign()); |
| |
| // Set up a dummy global to stand in for the metadata object while we produce |
| // relative references. |
| ConstantInitBuilder builder(IGM); |
| auto init = builder.beginStruct(); |
| init.setPacked(true); |
| |
| bool isPattern; |
| bool canBeConstant; |
| if (classDecl->isGenericContext()) { |
| GenericClassMetadataBuilder builder(IGM, classDecl, init, |
| layout, fieldLayout); |
| builder.layout(); |
| isPattern = true; |
| canBeConstant = false; |
| |
| maybeEmitNominalTypeMetadataAccessFunction(classDecl, builder); |
| } else { |
| ClassMetadataBuilder builder(IGM, classDecl, init, layout, fieldLayout); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| maybeEmitNominalTypeMetadataAccessFunction(classDecl, builder); |
| } |
| |
| CanType declaredType = classDecl->getDeclaredType()->getCanonicalType(); |
| |
| // For now, all type metadata is directly stored. |
| bool isIndirect = false; |
| |
| StringRef section{}; |
| if (classDecl->isObjC() && |
| IGM.TargetInfo.OutputObjectFormat == llvm::Triple::MachO) |
| section = "__DATA,__objc_data, regular"; |
| |
| auto var = IGM.defineTypeMetadata(declaredType, isIndirect, isPattern, |
| canBeConstant, |
| init.finishAndCreateFuture(), |
| section); |
| |
| // Add classes that don't require dynamic initialization to the |
| // ObjC class list. |
| if (IGM.ObjCInterop && !isPattern && !isIndirect && |
| !doesClassMetadataRequireDynamicInitialization(IGM, classDecl)) { |
| // Emit the ObjC class symbol to make the class visible to ObjC. |
| if (classDecl->isObjC()) { |
| emitObjCClassSymbol(IGM, classDecl, var); |
| } |
| |
| IGM.addObjCClass(var, |
| classDecl->getAttrs().hasAttribute<ObjCNonLazyRealizationAttr>()); |
| } |
| } |
| |
| llvm::Value *IRGenFunction::emitInvariantLoad(Address address, |
| const llvm::Twine &name) { |
| auto load = Builder.CreateLoad(address, name); |
| setInvariantLoad(load); |
| return load; |
| } |
| |
| void IRGenFunction::setInvariantLoad(llvm::LoadInst *load) { |
| load->setMetadata(IGM.InvariantMetadataID, IGM.InvariantNode); |
| } |
| |
| void IRGenFunction::setDereferenceableLoad(llvm::LoadInst *load, |
| unsigned size) { |
| auto sizeConstant = llvm::ConstantInt::get(IGM.Int64Ty, size); |
| auto sizeNode = llvm::MDNode::get(IGM.LLVMContext, |
| llvm::ConstantAsMetadata::get(sizeConstant)); |
| load->setMetadata(IGM.DereferenceableID, sizeNode); |
| } |
| |
| /// Emit a load from the given metadata at a constant index. |
| /// |
| /// The load is marked invariant. This function should not be called |
| /// on metadata objects that are in the process of being initialized. |
| static llvm::LoadInst * |
| emitInvariantLoadFromMetadataAtIndex(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| int index, |
| llvm::Type *objectTy, |
| const Twine &suffix = Twine::createNull()) { |
| auto result = emitLoadFromMetadataAtIndex(IGF, metadata, index, objectTy, |
| suffix); |
| IGF.setInvariantLoad(result); |
| return result; |
| } |
| |
| /// Given an AST type, load its value witness table. |
| llvm::Value * |
| IRGenFunction::emitValueWitnessTableRef(CanType type) { |
| // See if we have a cached projection we can use. |
| if (auto cached = tryGetLocalTypeData(type, |
| LocalTypeDataKind::forValueWitnessTable())) { |
| return cached; |
| } |
| |
| auto metadata = emitTypeMetadataRef(type); |
| auto vwtable = emitValueWitnessTableRefForMetadata(metadata); |
| setScopedLocalTypeData(type, LocalTypeDataKind::forValueWitnessTable(), |
| vwtable); |
| return vwtable; |
| } |
| |
| /// Given a type metadata pointer, load its value witness table. |
| llvm::Value * |
| IRGenFunction::emitValueWitnessTableRefForMetadata(llvm::Value *metadata) { |
| auto witness = emitInvariantLoadFromMetadataAtIndex(*this, metadata, -1, |
| IGM.WitnessTablePtrTy, |
| ".valueWitnesses"); |
| // A value witness table is dereferenceable to the number of value witness |
| // pointers. |
| |
| // TODO: If we know the type statically has extra inhabitants, we know |
| // there are more witnesses. |
| auto numValueWitnesses |
| = unsigned(ValueWitness::Last_RequiredValueWitness) + 1; |
| setDereferenceableLoad(witness, |
| IGM.getPointerSize().getValue() * numValueWitnesses); |
| return witness; |
| } |
| |
| /// Given a lowered SIL type, load a value witness table that represents its |
| /// layout. |
| llvm::Value * |
| IRGenFunction::emitValueWitnessTableRef(SILType type, |
| llvm::Value **metadataSlot) { |
| // See if we have a cached projection we can use. |
| if (auto cached = tryGetLocalTypeDataForLayout(type, |
| LocalTypeDataKind::forValueWitnessTable())) { |
| if (metadataSlot) |
| *metadataSlot = emitTypeMetadataRefForLayout(type); |
| return cached; |
| } |
| |
| auto metadata = emitTypeMetadataRefForLayout(type); |
| if (metadataSlot) *metadataSlot = metadata; |
| auto vwtable = emitValueWitnessTableRefForMetadata(metadata); |
| setScopedLocalTypeDataForLayout(type, |
| LocalTypeDataKind::forValueWitnessTable(), |
| vwtable); |
| return vwtable; |
| } |
| |
| /// Given a reference to class metadata of the given type, |
| /// load the fragile instance size and alignment of the class. |
| std::pair<llvm::Value *, llvm::Value *> |
| irgen::emitClassFragileInstanceSizeAndAlignMask(IRGenFunction &IGF, |
| ClassDecl *theClass, |
| llvm::Value *metadata) { |
| // FIXME: The below checks should capture this property already, but |
| // resilient class metadata layout is not fully implemented yet. |
| auto superClass = theClass; |
| do { |
| if (superClass->getParentModule() != IGF.IGM.getSwiftModule()) { |
| return emitClassResilientInstanceSizeAndAlignMask(IGF, theClass, |
| metadata); |
| } |
| } while ((superClass = superClass->getSuperclassDecl())); |
| |
| // If the class has fragile fixed layout, return the constant size and |
| // alignment. |
| if (llvm::Constant *size |
| = tryEmitClassConstantFragileInstanceSize(IGF.IGM, theClass)) { |
| llvm::Constant *alignMask |
| = tryEmitClassConstantFragileInstanceAlignMask(IGF.IGM, theClass); |
| assert(alignMask && "static size without static align"); |
| return {size, alignMask}; |
| } |
| |
| // Otherwise, load it from the metadata. |
| return emitClassResilientInstanceSizeAndAlignMask(IGF, theClass, metadata); |
| } |
| |
| std::pair<llvm::Value *, llvm::Value *> |
| irgen::emitClassResilientInstanceSizeAndAlignMask(IRGenFunction &IGF, |
| ClassDecl *theClass, |
| llvm::Value *metadata) { |
| auto &layout = IGF.IGM.getMetadataLayout(theClass); |
| |
| Address metadataAsBytes(IGF.Builder.CreateBitCast(metadata, IGF.IGM.Int8PtrTy), |
| IGF.IGM.getPointerAlignment()); |
| |
| Address slot = IGF.Builder.CreateConstByteArrayGEP( |
| metadataAsBytes, |
| layout.getInstanceSizeOffset()); |
| slot = IGF.Builder.CreateBitCast(slot, IGF.IGM.Int32Ty->getPointerTo()); |
| llvm::Value *size = IGF.Builder.CreateLoad(slot); |
| if (IGF.IGM.SizeTy != IGF.IGM.Int32Ty) |
| size = IGF.Builder.CreateZExt(size, IGF.IGM.SizeTy); |
| |
| slot = IGF.Builder.CreateConstByteArrayGEP( |
| metadataAsBytes, |
| layout.getInstanceAlignMaskOffset()); |
| slot = IGF.Builder.CreateBitCast(slot, IGF.IGM.Int16Ty->getPointerTo()); |
| llvm::Value *alignMask = IGF.Builder.CreateLoad(slot); |
| alignMask = IGF.Builder.CreateZExt(alignMask, IGF.IGM.SizeTy); |
| |
| return {size, alignMask}; |
| } |
| |
| /// Given a non-tagged object pointer, load a pointer to its class object. |
| llvm::Value *irgen::emitLoadOfObjCHeapMetadataRef(IRGenFunction &IGF, |
| llvm::Value *object) { |
| if (IGF.IGM.TargetInfo.hasISAMasking()) { |
| object = IGF.Builder.CreateBitCast(object, |
| IGF.IGM.IntPtrTy->getPointerTo()); |
| llvm::Value *metadata = |
| IGF.Builder.CreateLoad(Address(object, IGF.IGM.getPointerAlignment())); |
| llvm::Value *mask = IGF.Builder.CreateLoad(IGF.IGM.getAddrOfObjCISAMask()); |
| metadata = IGF.Builder.CreateAnd(metadata, mask); |
| metadata = IGF.Builder.CreateIntToPtr(metadata, IGF.IGM.TypeMetadataPtrTy); |
| return metadata; |
| } else if (IGF.IGM.TargetInfo.hasOpaqueISAs()) { |
| return emitHeapMetadataRefForUnknownHeapObject(IGF, object); |
| } else { |
| object = IGF.Builder.CreateBitCast(object, |
| IGF.IGM.TypeMetadataPtrTy->getPointerTo()); |
| llvm::Value *metadata = |
| IGF.Builder.CreateLoad(Address(object, IGF.IGM.getPointerAlignment())); |
| return metadata; |
| } |
| } |
| |
| /// Given a pointer to a heap object (i.e. definitely not a tagged |
| /// pointer), load its heap metadata pointer. |
| static llvm::Value *emitLoadOfHeapMetadataRef(IRGenFunction &IGF, |
| llvm::Value *object, |
| IsaEncoding isaEncoding, |
| bool suppressCast) { |
| switch (isaEncoding) { |
| case IsaEncoding::Pointer: { |
| // Drill into the object pointer. Rather than bitcasting, we make |
| // an effort to do something that should explode if we get something |
| // mistyped. |
| llvm::StructType *structTy = |
| cast<llvm::StructType>( |
| cast<llvm::PointerType>(object->getType())->getElementType()); |
| |
| llvm::Value *slot; |
| |
| // We need a bitcast if we're dealing with an opaque class. |
| if (structTy->isOpaque()) { |
| auto metadataPtrPtrTy = IGF.IGM.TypeMetadataPtrTy->getPointerTo(); |
| slot = IGF.Builder.CreateBitCast(object, metadataPtrPtrTy); |
| |
| // Otherwise, make a GEP. |
| } else { |
| auto zero = llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0); |
| |
| SmallVector<llvm::Value*, 4> indexes; |
| indexes.push_back(zero); |
| do { |
| indexes.push_back(zero); |
| |
| // Keep drilling down to the first element type. |
| auto eltTy = structTy->getElementType(0); |
| assert(isa<llvm::StructType>(eltTy) || eltTy == IGF.IGM.TypeMetadataPtrTy); |
| structTy = dyn_cast<llvm::StructType>(eltTy); |
| } while (structTy != nullptr); |
| |
| slot = IGF.Builder.CreateInBoundsGEP(object, indexes); |
| |
| if (!suppressCast) { |
| slot = IGF.Builder.CreateBitCast(slot, |
| IGF.IGM.TypeMetadataPtrTy->getPointerTo()); |
| } |
| } |
| |
| auto metadata = IGF.Builder.CreateLoad(Address(slot, |
| IGF.IGM.getPointerAlignment())); |
| if (IGF.IGM.EnableValueNames && object->hasName()) |
| metadata->setName(llvm::Twine(object->getName()) + ".metadata"); |
| return metadata; |
| } |
| |
| case IsaEncoding::ObjC: { |
| // Feed the object pointer to object_getClass. |
| llvm::Value *objcClass = emitLoadOfObjCHeapMetadataRef(IGF, object); |
| objcClass = IGF.Builder.CreateBitCast(objcClass, IGF.IGM.TypeMetadataPtrTy); |
| return objcClass; |
| } |
| } |
| |
| llvm_unreachable("Not a valid IsaEncoding."); |
| } |
| |
| /// Given an object of class type, produce the heap metadata reference |
| /// as an %objc_class*. |
| llvm::Value *irgen::emitHeapMetadataRefForHeapObject(IRGenFunction &IGF, |
| llvm::Value *object, |
| CanType objectType, |
| bool suppressCast) { |
| ClassDecl *theClass = objectType.getClassOrBoundGenericClass(); |
| if (theClass && isKnownNotTaggedPointer(IGF.IGM, theClass)) |
| return emitLoadOfHeapMetadataRef(IGF, object, |
| getIsaEncodingForType(IGF.IGM, objectType), |
| suppressCast); |
| |
| // OK, ask the runtime for the class pointer of this potentially-ObjC object. |
| return emitHeapMetadataRefForUnknownHeapObject(IGF, object); |
| } |
| |
| llvm::Value *irgen::emitHeapMetadataRefForHeapObject(IRGenFunction &IGF, |
| llvm::Value *object, |
| SILType objectType, |
| bool suppressCast) { |
| return emitHeapMetadataRefForHeapObject(IGF, object, |
| objectType.getSwiftRValueType(), |
| suppressCast); |
| } |
| |
| /// Given an opaque class instance pointer, produce the type metadata reference |
| /// as a %type*. |
| llvm::Value *irgen::emitDynamicTypeOfOpaqueHeapObject(IRGenFunction &IGF, |
| llvm::Value *object) { |
| object = IGF.Builder.CreateBitCast(object, IGF.IGM.ObjCPtrTy); |
| auto metadata = IGF.Builder.CreateCall(IGF.IGM.getGetObjectTypeFn(), |
| object, |
| object->getName() + ".Type"); |
| metadata->setDoesNotThrow(); |
| metadata->setOnlyReadsMemory(); |
| return metadata; |
| } |
| |
| llvm::Value *irgen:: |
| emitHeapMetadataRefForUnknownHeapObject(IRGenFunction &IGF, |
| llvm::Value *object) { |
| object = IGF.Builder.CreateBitCast(object, IGF.IGM.ObjCPtrTy); |
| auto metadata = IGF.Builder.CreateCall(IGF.IGM.getGetObjectClassFn(), |
| object, |
| object->getName() + ".Type"); |
| metadata->setCallingConv(llvm::CallingConv::C); |
| metadata->setDoesNotThrow(); |
| metadata->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadOnly); |
| return metadata; |
| } |
| |
| /// Given an object of class type, produce the type metadata reference |
| /// as a %type*. |
| llvm::Value *irgen::emitDynamicTypeOfHeapObject(IRGenFunction &IGF, |
| llvm::Value *object, |
| SILType objectType, |
| bool suppressCast) { |
| // If it is known to have swift metadata, just load. |
| if (hasKnownSwiftMetadata(IGF.IGM, objectType.getSwiftRValueType())) { |
| return emitLoadOfHeapMetadataRef(IGF, object, |
| getIsaEncodingForType(IGF.IGM, objectType.getSwiftRValueType()), |
| suppressCast); |
| } |
| |
| // Okay, ask the runtime for the type metadata of this |
| // potentially-ObjC object. |
| return emitDynamicTypeOfOpaqueHeapObject(IGF, object); |
| } |
| |
| /// Given a class metatype, produce the necessary heap metadata |
| /// reference. This is generally the metatype pointer, but may |
| /// instead be a reference type. |
| llvm::Value *irgen::emitClassHeapMetadataRefForMetatype(IRGenFunction &IGF, |
| llvm::Value *metatype, |
| CanType type) { |
| // If the type is known to have Swift metadata, this is trivial. |
| if (hasKnownSwiftMetadata(IGF.IGM, type)) |
| return metatype; |
| |
| // Otherwise, we may have to unwrap an ObjC class wrapper. |
| assert(IGF.IGM.Context.LangOpts.EnableObjCInterop); |
| metatype = IGF.Builder.CreateBitCast(metatype, IGF.IGM.TypeMetadataPtrTy); |
| |
| // Fetch the metadata for that class. |
| auto call = IGF.Builder.CreateCall(IGF.IGM.getGetObjCClassFromMetadataFn(), |
| metatype); |
| call->setDoesNotThrow(); |
| call->setDoesNotAccessMemory(); |
| return call; |
| } |
| |
| /// Load the correct virtual function for the given class method. |
| FunctionPointer irgen::emitVirtualMethodValue(IRGenFunction &IGF, |
| llvm::Value *base, |
| SILType baseType, |
| SILDeclRef method, |
| CanSILFunctionType methodType, |
| bool useSuperVTable) { |
| AbstractFunctionDecl *methodDecl |
| = cast<AbstractFunctionDecl>(method.getDecl()); |
| |
| // Find the vtable entry for this method. |
| SILDeclRef overridden = IGF.IGM.getSILTypes().getOverriddenVTableEntry(method); |
| |
| // Find the metadata. |
| llvm::Value *metadata; |
| if (useSuperVTable) { |
| auto instanceTy = baseType; |
| if (auto metaTy = dyn_cast<MetatypeType>(baseType.getSwiftRValueType())) |
| instanceTy = SILType::getPrimitiveObjectType(metaTy.getInstanceType()); |
| |
| if (IGF.IGM.isResilient(instanceTy.getClassOrBoundGenericClass(), |
| ResilienceExpansion::Maximal)) { |
| // The derived type that is making the super call is resilient, |
| // for example we may be in an extension of a class outside of our |
| // resilience domain. So, we need to load the superclass metadata |
| // dynamically. |
| |
| metadata = emitClassHeapMetadataRef(IGF, instanceTy.getSwiftRValueType(), |
| MetadataValueType::TypeMetadata); |
| auto superField = emitAddressOfSuperclassRefInClassMetadata(IGF, metadata); |
| metadata = IGF.Builder.CreateLoad(superField); |
| } else { |
| // Otherwise, we can directly load the statically known superclass's |
| // metadata. |
| auto superTy = instanceTy.getSuperclass(); |
| metadata = emitClassHeapMetadataRef(IGF, superTy.getSwiftRValueType(), |
| MetadataValueType::TypeMetadata); |
| } |
| } else { |
| if ((isa<FuncDecl>(methodDecl) && cast<FuncDecl>(methodDecl)->isStatic()) || |
| (isa<ConstructorDecl>(methodDecl) && |
| method.kind == SILDeclRef::Kind::Allocator)) { |
| metadata = base; |
| } else { |
| metadata = emitHeapMetadataRefForHeapObject(IGF, base, baseType, |
| /*suppress cast*/ true); |
| } |
| } |
| |
| // Use the type of the method we were type-checked against, not the |
| // type of the overridden method. |
| auto sig = IGF.IGM.getSignature(methodType); |
| |
| auto declaringClass = cast<ClassDecl>(overridden.getDecl()->getDeclContext()); |
| |
| auto methodInfo = |
| IGF.IGM.getMetadataLayout(declaringClass).getMethodInfo(IGF, overridden); |
| auto offset = methodInfo.getOffset(); |
| |
| auto slot = IGF.emitAddressAtOffset(metadata, offset, |
| sig.getType()->getPointerTo(), |
| IGF.IGM.getPointerAlignment()); |
| auto fnPtr = IGF.emitInvariantLoad(slot); |
| |
| return FunctionPointer(fnPtr, sig); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Value types (structs and enums) |
| //===----------------------------------------------------------------------===// |
| |
| static llvm::Value * |
| emitInPlaceValueTypeMetadataInitialization(IRGenFunction &IGF, |
| CanNominalType type, |
| llvm::Value *metadata) { |
| // All the value types are basically similar. |
| assert(isa<StructType>(type) || isa<EnumType>(type)); |
| |
| // Set up the value witness table if it's dependent. |
| SILType loweredType = IGF.IGM.getLoweredType(AbstractionPattern(type), type); |
| auto &ti = IGF.IGM.getTypeInfo(loweredType); |
| if (!ti.isFixedSize()) { |
| // We assume that that value witness table will already have been written |
| // into the metadata; just load it. |
| llvm::Value *vwtable = IGF.emitValueWitnessTableRefForMetadata(metadata); |
| |
| // Initialize the metadata. |
| ti.initializeMetadata(IGF, metadata, vwtable, loweredType.getAddressType()); |
| } |
| |
| return metadata; |
| } |
| |
| /// Create an access function for the type metadata of the given |
| /// non-generic nominal type. |
| static void createInPlaceValueTypeMetadataAccessFunction(IRGenModule &IGM, |
| NominalTypeDecl *typeDecl) { |
| assert(!typeDecl->isGenericContext()); |
| auto type = |
| cast<NominalType>(typeDecl->getDeclaredType()->getCanonicalType()); |
| |
| (void) getTypeMetadataAccessFunction(IGM, type, ForDefinition, |
| [&](IRGenFunction &IGF, |
| llvm::Constant *cacheVariable) { |
| return emitInPlaceTypeMetadataAccessFunctionBody(IGF, type, cacheVariable, |
| [&](IRGenFunction &IGF, llvm::Value *metadata) { |
| return emitInPlaceValueTypeMetadataInitialization(IGF, type, metadata); |
| }); |
| }); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Structs |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| /// An adapter for laying out struct metadata. |
| template <class Impl> |
| class StructMetadataBuilderBase : public StructMetadataVisitor<Impl> { |
| using super = StructMetadataVisitor<Impl>; |
| |
| protected: |
| ConstantStructBuilder &B; |
| using super::IGM; |
| using super::Target; |
| using super::asImpl; |
| |
| StructMetadataBuilderBase(IRGenModule &IGM, StructDecl *theStruct, |
| ConstantStructBuilder &B) |
| : super(IGM, theStruct), B(B) { |
| } |
| |
| public: |
| void addMetadataFlags() { |
| B.addInt(IGM.MetadataKindTy, unsigned(MetadataKind::Struct)); |
| } |
| |
| void addNominalTypeDescriptor() { |
| auto *descriptor = StructNominalTypeDescriptorBuilder(IGM, Target).emit(); |
| B.add(descriptor); |
| } |
| |
| void addFieldOffset(VarDecl *var) { |
| assert(var->hasStorage() && |
| "storing field offset for computed property?!"); |
| SILType structType = |
| IGM.getLoweredType(Target->getDeclaredTypeInContext()); |
| |
| llvm::Constant *offset = |
| emitPhysicalStructMemberFixedOffset(IGM, structType, var); |
| // If we have a fixed offset, add it. Otherwise, leave zero as a |
| // placeholder. |
| if (offset) { |
| B.add(offset); |
| } else { |
| asImpl().flagUnfilledFieldOffset(); |
| B.addInt(IGM.IntPtrTy, 0); |
| } |
| } |
| |
| void addGenericArgument(CanType type) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addGenericWitnessTable(CanType type, ProtocolConformanceRef conf) { |
| B.addNullPointer(IGM.WitnessTablePtrTy); |
| } |
| }; |
| |
| class StructMetadataBuilder : |
| public StructMetadataBuilderBase<StructMetadataBuilder> { |
| |
| bool HasUnfilledFieldOffset = false; |
| public: |
| StructMetadataBuilder(IRGenModule &IGM, StructDecl *theStruct, |
| ConstantStructBuilder &B) |
| : StructMetadataBuilderBase(IGM, theStruct, B) {} |
| |
| void flagUnfilledFieldOffset() { |
| HasUnfilledFieldOffset = true; |
| } |
| |
| bool canBeConstant() { |
| return !HasUnfilledFieldOffset; |
| } |
| |
| void addValueWitnessTable() { |
| auto type = this->Target->getDeclaredType()->getCanonicalType(); |
| B.add(emitValueWitnessTable(IGM, type)); |
| } |
| |
| void createMetadataAccessFunction() { |
| createInPlaceValueTypeMetadataAccessFunction(IGM, Target); |
| } |
| }; |
| |
| /// Emit a value witness table for a fixed-layout generic type, or a null |
| /// placeholder if the value witness table is dependent on generic parameters. |
| /// Returns nullptr if the value witness table is dependent. |
| static llvm::Constant * |
| getValueWitnessTableForGenericValueType(IRGenModule &IGM, |
| NominalTypeDecl *decl, |
| bool &dependent) { |
| CanType unboundType |
| = decl->getDeclaredType()->getCanonicalType(); |
| |
| dependent = hasDependentValueWitnessTable(IGM, unboundType); |
| if (dependent) |
| return llvm::ConstantPointerNull::get(IGM.Int8PtrTy); |
| else |
| return emitValueWitnessTable(IGM, unboundType); |
| } |
| |
| /// A builder for metadata templates. |
| class GenericStructMetadataBuilder : |
| public GenericMetadataBuilderBase<GenericStructMetadataBuilder, |
| StructMetadataBuilderBase<GenericStructMetadataBuilder>> { |
| |
| typedef GenericMetadataBuilderBase super; |
| |
| public: |
| GenericStructMetadataBuilder(IRGenModule &IGM, StructDecl *theStruct, |
| ConstantStructBuilder &B) |
| : super(IGM, theStruct, B) {} |
| |
| llvm::Value *emitAllocateMetadata(IRGenFunction &IGF, |
| llvm::Value *metadataPattern, |
| llvm::Value *arguments) { |
| return IGF.Builder.CreateCall(IGM.getAllocateGenericValueMetadataFn(), |
| {metadataPattern, arguments}); |
| } |
| |
| void flagUnfilledFieldOffset() { |
| // We just assume this might happen. |
| } |
| |
| void addValueWitnessTable() { |
| B.add(getValueWitnessTableForGenericValueType(IGM, Target, |
| HasDependentVWT)); |
| } |
| |
| void addDependentValueWitnessTablePattern() { |
| emitDependentValueWitnessTablePattern(IGM, B, |
| Target->getDeclaredType()->getCanonicalType()); |
| } |
| |
| void emitInitializeMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| llvm::Value *vwtable) { |
| // Nominal types are always preserved through SIL lowering. |
| auto structTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| IGM.getTypeInfoForUnlowered(structTy) |
| .initializeMetadata(IGF, metadata, vwtable, |
| IGF.IGM.getLoweredType(structTy)); |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// Emit the type metadata or metadata template for a struct. |
| void irgen::emitStructMetadata(IRGenModule &IGM, StructDecl *structDecl) { |
| // TODO: structs nested within generic types |
| ConstantInitBuilder initBuilder(IGM); |
| auto init = initBuilder.beginStruct(); |
| init.setPacked(true); |
| |
| bool isPattern; |
| bool canBeConstant; |
| if (structDecl->isGenericContext()) { |
| GenericStructMetadataBuilder builder(IGM, structDecl, init); |
| builder.layout(); |
| isPattern = true; |
| canBeConstant = false; |
| |
| maybeEmitNominalTypeMetadataAccessFunction(structDecl, builder); |
| } else { |
| StructMetadataBuilder builder(IGM, structDecl, init); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| maybeEmitNominalTypeMetadataAccessFunction(structDecl, builder); |
| } |
| |
| CanType declaredType = structDecl->getDeclaredType()->getCanonicalType(); |
| |
| // For now, all type metadata is directly stored. |
| bool isIndirect = false; |
| |
| IGM.defineTypeMetadata(declaredType, isIndirect, isPattern, |
| canBeConstant, init.finishAndCreateFuture()); |
| } |
| |
| // Enums |
| |
| namespace { |
| |
| template<class Impl> |
| class EnumMetadataBuilderBase : public EnumMetadataVisitor<Impl> { |
| using super = EnumMetadataVisitor<Impl>; |
| |
| protected: |
| ConstantStructBuilder &B; |
| using super::IGM; |
| using super::Target; |
| |
| public: |
| EnumMetadataBuilderBase(IRGenModule &IGM, EnumDecl *theEnum, |
| ConstantStructBuilder &B) |
| : super(IGM, theEnum), B(B) { |
| } |
| |
| void addMetadataFlags() { |
| auto kind = Target->classifyAsOptionalType() |
| ? MetadataKind::Optional |
| : MetadataKind::Enum; |
| B.addInt(IGM.MetadataKindTy, unsigned(kind)); |
| } |
| |
| void addNominalTypeDescriptor() { |
| auto descriptor = EnumNominalTypeDescriptorBuilder(IGM, Target).emit(); |
| B.add(descriptor); |
| } |
| |
| void addGenericArgument(CanType type) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addGenericWitnessTable(CanType type, ProtocolConformanceRef conf) { |
| B.addNullPointer(IGM.WitnessTablePtrTy); |
| } |
| }; |
| |
| class EnumMetadataBuilder |
| : public EnumMetadataBuilderBase<EnumMetadataBuilder> { |
| bool HasUnfilledPayloadSize = false; |
| |
| public: |
| EnumMetadataBuilder(IRGenModule &IGM, EnumDecl *theEnum, |
| ConstantStructBuilder &B) |
| : EnumMetadataBuilderBase(IGM, theEnum, B) {} |
| |
| void addValueWitnessTable() { |
| auto type = Target->getDeclaredType()->getCanonicalType(); |
| B.add(emitValueWitnessTable(IGM, type)); |
| } |
| |
| void addPayloadSize() { |
| auto enumTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| auto &enumTI = IGM.getTypeInfoForUnlowered(enumTy); |
| if (!enumTI.isFixedSize(ResilienceExpansion::Maximal)) { |
| B.addInt(IGM.IntPtrTy, 0); |
| HasUnfilledPayloadSize = true; |
| return; |
| } |
| |
| assert(!enumTI.isFixedSize(ResilienceExpansion::Minimal) && |
| "non-generic, non-resilient enums don't need payload size in metadata"); |
| auto &strategy = getEnumImplStrategy(IGM, enumTy); |
| B.addInt(IGM.IntPtrTy, strategy.getPayloadSizeForMetadata()); |
| } |
| |
| bool canBeConstant() { |
| return !HasUnfilledPayloadSize; |
| } |
| |
| void createMetadataAccessFunction() { |
| createInPlaceValueTypeMetadataAccessFunction(IGM, Target); |
| } |
| }; |
| |
| class GenericEnumMetadataBuilder |
| : public GenericMetadataBuilderBase<GenericEnumMetadataBuilder, |
| EnumMetadataBuilderBase<GenericEnumMetadataBuilder>> |
| { |
| public: |
| GenericEnumMetadataBuilder(IRGenModule &IGM, EnumDecl *theEnum, |
| ConstantStructBuilder &B) |
| : GenericMetadataBuilderBase(IGM, theEnum, B) {} |
| |
| llvm::Value *emitAllocateMetadata(IRGenFunction &IGF, |
| llvm::Value *metadataPattern, |
| llvm::Value *arguments) { |
| return IGF.Builder.CreateCall(IGM.getAllocateGenericValueMetadataFn(), |
| {metadataPattern, arguments}); |
| } |
| |
| void addValueWitnessTable() { |
| B.add(getValueWitnessTableForGenericValueType(IGM, Target, |
| HasDependentVWT)); |
| } |
| |
| void addDependentValueWitnessTablePattern() { |
| emitDependentValueWitnessTablePattern(IGM, B, |
| Target->getDeclaredType()->getCanonicalType()); |
| } |
| |
| void addPayloadSize() { |
| // In all cases where a payload size is demanded in the metadata, it's |
| // runtime-dependent, so fill in a zero here. |
| auto enumTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| auto &enumTI = IGM.getTypeInfoForUnlowered(enumTy); |
| (void) enumTI; |
| assert(!enumTI.isFixedSize(ResilienceExpansion::Minimal) && |
| "non-generic, non-resilient enums don't need payload size in metadata"); |
| B.addInt(IGM.IntPtrTy, 0); |
| } |
| |
| void emitInitializeMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| llvm::Value *vwtable) { |
| // Nominal types are always preserved through SIL lowering. |
| auto enumTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| IGM.getTypeInfoForUnlowered(enumTy) |
| .initializeMetadata(IGF, metadata, vwtable, |
| IGF.IGM.getLoweredType(enumTy)); |
| } |
| }; |
| |
| } // end anonymous namespace |
| |
| void irgen::emitEnumMetadata(IRGenModule &IGM, EnumDecl *theEnum) { |
| // TODO: enums nested inside generic types |
| ConstantInitBuilder initBuilder(IGM); |
| auto init = initBuilder.beginStruct(); |
| init.setPacked(true); |
| |
| bool isPattern; |
| bool canBeConstant; |
| if (theEnum->isGenericContext()) { |
| GenericEnumMetadataBuilder builder(IGM, theEnum, init); |
| builder.layout(); |
| isPattern = true; |
| canBeConstant = false; |
| |
| maybeEmitNominalTypeMetadataAccessFunction(theEnum, builder); |
| } else { |
| EnumMetadataBuilder builder(IGM, theEnum, init); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| maybeEmitNominalTypeMetadataAccessFunction(theEnum, builder); |
| } |
| |
| CanType declaredType = theEnum->getDeclaredType()->getCanonicalType(); |
| |
| // For now, all type metadata is directly stored. |
| bool isIndirect = false; |
| |
| IGM.defineTypeMetadata(declaredType, isIndirect, isPattern, |
| canBeConstant, init.finishAndCreateFuture()); |
| } |
| |
| llvm::Value *IRGenFunction::emitObjCSelectorRefLoad(StringRef selector) { |
| llvm::Constant *loadSelRef = IGM.getAddrOfObjCSelectorRef(selector); |
| llvm::Value *loadSel = |
| Builder.CreateLoad(Address(loadSelRef, IGM.getPointerAlignment())); |
| |
| // When generating JIT'd code, we need to call sel_registerName() to force |
| // the runtime to unique the selector. For non-JIT'd code, the linker will |
| // do it for us. |
| if (IGM.IRGen.Opts.UseJIT) { |
| loadSel = Builder.CreateCall(IGM.getObjCSelRegisterNameFn(), loadSel); |
| } |
| |
| return loadSel; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Foreign types |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| /// A CRTP layout class for foreign class metadata. |
| template <class Impl> |
| class ForeignClassMetadataVisitor |
| : public NominalMetadataVisitor<Impl> { |
| using super = NominalMetadataVisitor<Impl>; |
| protected: |
| ClassDecl *Target; |
| using super::asImpl; |
| public: |
| ForeignClassMetadataVisitor(IRGenModule &IGM, ClassDecl *target) |
| : super(IGM), Target(target) {} |
| |
| void layout() { |
| super::layout(); |
| asImpl().addSuperClass(); |
| asImpl().addReservedWord(); |
| asImpl().addReservedWord(); |
| asImpl().addReservedWord(); |
| } |
| |
| bool requiresInitializationFunction() { |
| // TODO: superclasses? |
| return false; |
| } |
| |
| CanType getTargetType() const { |
| return Target->getDeclaredType()->getCanonicalType(); |
| } |
| }; |
| |
| /// An adapter that turns a metadata layout class into a foreign metadata |
| /// layout class. Foreign metadata has an additional header that |
| template<typename Impl, typename Base> |
| class ForeignMetadataBuilderBase : public Base { |
| typedef Base super; |
| |
| protected: |
| using super::IGM; |
| using super::asImpl; |
| using super::B; |
| |
| template <class... T> |
| ForeignMetadataBuilderBase(T &&...args) : super(std::forward<T>(args)...) {} |
| |
| Size AddressPoint = Size::invalid(); |
| |
| public: |
| void layout() { |
| if (asImpl().requiresInitializationFunction()) |
| asImpl().addInitializationFunction(); |
| asImpl().addForeignName(); |
| asImpl().addUniquePointer(); |
| asImpl().addForeignFlags(); |
| super::layout(); |
| } |
| |
| void addForeignFlags() { |
| int64_t flags = 0; |
| if (asImpl().requiresInitializationFunction()) flags |= 1; |
| B.addInt(IGM.IntPtrTy, flags); |
| } |
| |
| void addForeignName() { |
| CanType targetType = asImpl().getTargetType(); |
| B.add(getMangledTypeName(IGM, targetType)); |
| } |
| |
| void addUniquePointer() { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addInitializationFunction() { |
| auto type = cast<NominalType>(asImpl().getTargetType()); |
| |
| auto fnTy = llvm::FunctionType::get(IGM.VoidTy, {IGM.TypeMetadataPtrTy}, |
| /*variadic*/ false); |
| llvm::Function *fn = llvm::Function::Create(fnTy, |
| llvm::GlobalValue::PrivateLinkage, |
| Twine("initialize_metadata_") |
| + type->getDecl()->getName().str(), |
| &IGM.Module); |
| fn->setAttributes(IGM.constructInitialAttributes()); |
| |
| // Set up the function. |
| IRGenFunction IGF(IGM, fn); |
| if (IGM.DebugInfo) |
| IGM.DebugInfo->emitArtificialFunction(IGF, fn); |
| |
| // Emit the initialization. |
| llvm::Value *metadata = IGF.collectParameters().claimNext(); |
| asImpl().emitInitialization(IGF, metadata); |
| |
| IGF.Builder.CreateRetVoid(); |
| |
| B.add(fn); |
| } |
| |
| void noteAddressPoint() { |
| AddressPoint = B.getNextOffsetFromGlobal(); |
| } |
| |
| Size getOffsetOfAddressPoint() const { return AddressPoint; } |
| }; |
| |
| class ForeignClassMetadataBuilder; |
| class ForeignClassMetadataBuilderBase : |
| public ForeignClassMetadataVisitor<ForeignClassMetadataBuilder> { |
| protected: |
| ConstantStructBuilder &B; |
| |
| ForeignClassMetadataBuilderBase(IRGenModule &IGM, ClassDecl *target, |
| ConstantStructBuilder &B) |
| : ForeignClassMetadataVisitor(IGM, target), B(B) {} |
| }; |
| |
| /// A builder for ForeignClassMetadata. |
| class ForeignClassMetadataBuilder : |
| public ForeignMetadataBuilderBase<ForeignClassMetadataBuilder, |
| ForeignClassMetadataBuilderBase> { |
| public: |
| ForeignClassMetadataBuilder(IRGenModule &IGM, ClassDecl *target, |
| ConstantStructBuilder &B) |
| : ForeignMetadataBuilderBase(IGM, target, B) {} |
| |
| void emitInitialization(IRGenFunction &IGF, llvm::Value *metadata) { |
| // TODO: superclasses? |
| llvm_unreachable("no supported forms of initialization"); |
| } |
| |
| // Visitor methods. |
| |
| void addValueWitnessTable() { |
| // Without Objective-C interop, foreign classes must still use |
| // Swift native reference counting. |
| auto type = (IGM.ObjCInterop |
| ? IGM.Context.TheUnknownObjectType |
| : IGM.Context.TheNativeObjectType); |
| auto wtable = IGM.getAddrOfValueWitnessTable(type); |
| B.add(wtable); |
| } |
| |
| void addMetadataFlags() { |
| B.addInt(IGM.MetadataKindTy, (unsigned) MetadataKind::ForeignClass); |
| } |
| |
| void addSuperClass() { |
| // TODO: superclasses |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addReservedWord() { |
| B.addNullPointer(IGM.Int8PtrTy); |
| } |
| }; |
| |
| /// A builder for ForeignStructMetadata. |
| class ForeignStructMetadataBuilder : |
| public ForeignMetadataBuilderBase<ForeignStructMetadataBuilder, |
| StructMetadataBuilderBase<ForeignStructMetadataBuilder>> |
| { |
| public: |
| ForeignStructMetadataBuilder(IRGenModule &IGM, StructDecl *target, |
| ConstantStructBuilder &builder) |
| : ForeignMetadataBuilderBase(IGM, target, builder) {} |
| |
| CanType getTargetType() const { |
| return Target->getDeclaredType()->getCanonicalType(); |
| } |
| |
| bool requiresInitializationFunction() const { |
| return false; |
| } |
| void emitInitialization(IRGenFunction &IGF, llvm::Value *metadata) {} |
| |
| void addValueWitnessTable() { |
| auto type = this->Target->getDeclaredType()->getCanonicalType(); |
| B.add(emitValueWitnessTable(IGM, type)); |
| } |
| |
| void flagUnfilledFieldOffset() { |
| llvm_unreachable("foreign type with non-fixed layout?"); |
| } |
| }; |
| |
| /// A builder for ForeignEnumMetadata. |
| class ForeignEnumMetadataBuilder : |
| public ForeignMetadataBuilderBase<ForeignEnumMetadataBuilder, |
| EnumMetadataBuilderBase<ForeignEnumMetadataBuilder>> |
| { |
| public: |
| ForeignEnumMetadataBuilder(IRGenModule &IGM, EnumDecl *target, |
| ConstantStructBuilder &builder) |
| : ForeignMetadataBuilderBase(IGM, target, builder) {} |
| |
| CanType getTargetType() const { |
| return Target->getDeclaredType()->getCanonicalType(); |
| } |
| |
| bool requiresInitializationFunction() const { |
| return false; |
| } |
| void emitInitialization(IRGenFunction &IGF, llvm::Value *metadata) {} |
| |
| void addValueWitnessTable() { |
| auto type = this->Target->getDeclaredType()->getCanonicalType(); |
| B.add(emitValueWitnessTable(IGM, type)); |
| } |
| |
| void addPayloadSize() const { |
| llvm_unreachable("nongeneric enums shouldn't need payload size in metadata"); |
| } |
| }; |
| } // end anonymous namespace |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfForeignTypeMetadataCandidate(CanType type) { |
| // What we save in GlobalVars is actually the offsetted value. |
| auto entity = LinkEntity::forForeignTypeMetadataCandidate(type); |
| if (auto entry = GlobalVars[entity]) |
| return entry; |
| |
| // Create a temporary base for relative references. |
| ConstantInitBuilder builder(*this); |
| auto init = builder.beginStruct(); |
| init.setPacked(true); |
| |
| // Compute the constant initializer and the offset of the type |
| // metadata candidate within it. |
| Size addressPoint; |
| if (auto classType = dyn_cast<ClassType>(type)) { |
| assert(!classType.getParent()); |
| auto classDecl = classType->getDecl(); |
| assert(classDecl->isForeign()); |
| |
| ForeignClassMetadataBuilder builder(*this, classDecl, init); |
| builder.layout(); |
| addressPoint = builder.getOffsetOfAddressPoint(); |
| } else if (auto structType = dyn_cast<StructType>(type)) { |
| auto structDecl = structType->getDecl(); |
| assert(isa<ClangModuleUnit>(structDecl->getModuleScopeContext())); |
| |
| ForeignStructMetadataBuilder builder(*this, structDecl, init); |
| builder.layout(); |
| addressPoint = builder.getOffsetOfAddressPoint(); |
| } else if (auto enumType = dyn_cast<EnumType>(type)) { |
| auto enumDecl = enumType->getDecl(); |
| assert(enumDecl->hasClangNode()); |
| |
| ForeignEnumMetadataBuilder builder(*this, enumDecl, init); |
| builder.layout(); |
| addressPoint = builder.getOffsetOfAddressPoint(); |
| } else { |
| llvm_unreachable("foreign metadata for unexpected type?!"); |
| } |
| |
| auto definition = init.finishAndCreateFuture(); |
| |
| // Create the global variable. |
| LinkInfo link = LinkInfo::get(*this, entity, ForDefinition); |
| auto var = |
| createVariable(*this, link, definition.getType(), getPointerAlignment()); |
| definition.installInGlobal(var); |
| |
| // Apply the offset. |
| llvm::Constant *result = var; |
| result = llvm::ConstantExpr::getBitCast(result, Int8PtrTy); |
| result = llvm::ConstantExpr::getInBoundsGetElementPtr( |
| Int8Ty, result, getSize(addressPoint)); |
| result = llvm::ConstantExpr::getBitCast(result, TypeMetadataPtrTy); |
| |
| // Only remember the offset. |
| GlobalVars[entity] = result; |
| |
| if (NominalTypeDecl *Nominal = type->getAnyNominal()) { |
| addLazyConformances(Nominal); |
| } |
| |
| return result; |
| } |
| |
| // Protocols |
| |
| /// Get the runtime identifier for a special protocol, if any. |
| SpecialProtocol irgen::getSpecialProtocolID(ProtocolDecl *P) { |
| auto known = P->getKnownProtocolKind(); |
| if (!known) |
| return SpecialProtocol::None; |
| switch (*known) { |
| case KnownProtocolKind::Error: |
| return SpecialProtocol::Error; |
| |
| // The other known protocols aren't special at runtime. |
| case KnownProtocolKind::Sequence: |
| case KnownProtocolKind::IteratorProtocol: |
| case KnownProtocolKind::RawRepresentable: |
| case KnownProtocolKind::Equatable: |
| case KnownProtocolKind::Hashable: |
| case KnownProtocolKind::Comparable: |
| case KnownProtocolKind::ObjectiveCBridgeable: |
| case KnownProtocolKind::DestructorSafeContainer: |
| case KnownProtocolKind::SwiftNewtypeWrapper: |
| case KnownProtocolKind::ExpressibleByArrayLiteral: |
| case KnownProtocolKind::ExpressibleByBooleanLiteral: |
| case KnownProtocolKind::ExpressibleByDictionaryLiteral: |
| case KnownProtocolKind::ExpressibleByExtendedGraphemeClusterLiteral: |
| case KnownProtocolKind::ExpressibleByFloatLiteral: |
| case KnownProtocolKind::ExpressibleByIntegerLiteral: |
| case KnownProtocolKind::ExpressibleByStringInterpolation: |
| case KnownProtocolKind::ExpressibleByStringLiteral: |
| case KnownProtocolKind::ExpressibleByNilLiteral: |
| case KnownProtocolKind::ExpressibleByUnicodeScalarLiteral: |
| case KnownProtocolKind::ExpressibleByColorLiteral: |
| case KnownProtocolKind::ExpressibleByImageLiteral: |
| case KnownProtocolKind::ExpressibleByFileReferenceLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinBooleanLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinUTF16ExtendedGraphemeClusterLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinExtendedGraphemeClusterLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinFloatLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinIntegerLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinStringLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinUTF16StringLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinUnicodeScalarLiteral: |
| case KnownProtocolKind::OptionSet: |
| case KnownProtocolKind::BridgedNSError: |
| case KnownProtocolKind::BridgedStoredNSError: |
| case KnownProtocolKind::CFObject: |
| case KnownProtocolKind::ErrorCodeProtocol: |
| case KnownProtocolKind::ExpressibleByBuiltinConstStringLiteral: |
| case KnownProtocolKind::ExpressibleByBuiltinConstUTF16StringLiteral: |
| case KnownProtocolKind::CodingKey: |
| case KnownProtocolKind::Encodable: |
| case KnownProtocolKind::Decodable: |
| return SpecialProtocol::None; |
| } |
| |
| llvm_unreachable("Not a valid KnownProtocolKind."); |
| } |
| |
| namespace { |
| class ProtocolDescriptorBuilder { |
| IRGenModule &IGM; |
| ConstantStructBuilder &B; |
| ProtocolDecl *Protocol; |
| SILDefaultWitnessTable *DefaultWitnesses; |
| |
| public: |
| ProtocolDescriptorBuilder(IRGenModule &IGM, ProtocolDecl *protocol, |
| ConstantStructBuilder &B, |
| SILDefaultWitnessTable *defaultWitnesses) |
| : IGM(IGM), B(B), Protocol(protocol), |
| DefaultWitnesses(defaultWitnesses) {} |
| |
| void layout() { |
| addObjCCompatibilityIsa(); |
| addName(); |
| addInherited(); |
| addObjCCompatibilityTables(); |
| addSize(); |
| addFlags(); |
| addRequirements(); |
| |
| B.suggestType(IGM.ProtocolDescriptorStructTy); |
| } |
| |
| void addObjCCompatibilityIsa() { |
| // The ObjC runtime will drop a reference to its magic Protocol class |
| // here. |
| B.addNullPointer(IGM.Int8PtrTy); |
| } |
| |
| void addName() { |
| // Include the _Tt prefix. Since Swift protocol descriptors are laid |
| // out to look like ObjC Protocol* objects, the name has to clearly be |
| // a Swift mangled name. |
| |
| IRGenMangler mangler; |
| std::string Name = |
| mangler.mangleForProtocolDescriptor(Protocol->getDeclaredType()); |
| |
| auto global = IGM.getAddrOfGlobalString(Name); |
| B.add(global); |
| } |
| |
| void addInherited() { |
| // If there are no inherited protocols, produce null. |
| auto inherited = Protocol->getInheritedProtocols(); |
| if (inherited.empty()) { |
| B.addNullPointer(IGM.Int8PtrTy); |
| return; |
| } |
| |
| // Otherwise, collect references to all of the inherited protocol |
| // descriptors. |
| SmallVector<llvm::Constant*, 4> inheritedDescriptors; |
| inheritedDescriptors.push_back(IGM.getSize(Size(inherited.size()))); |
| |
| for (ProtocolDecl *p : inherited) { |
| auto descriptor = IGM.getAddrOfProtocolDescriptor(p); |
| inheritedDescriptors.push_back(descriptor); |
| } |
| |
| auto inheritedInit = llvm::ConstantStruct::getAnon(inheritedDescriptors); |
| auto inheritedVar = new llvm::GlobalVariable(IGM.Module, |
| inheritedInit->getType(), |
| /*isConstant*/ true, |
| llvm::GlobalValue::PrivateLinkage, |
| inheritedInit); |
| |
| B.addBitCast(inheritedVar, IGM.Int8PtrTy); |
| } |
| |
| void addObjCCompatibilityTables() { |
| // Required instance methods |
| B.addNullPointer(IGM.Int8PtrTy); |
| // Required class methods |
| B.addNullPointer(IGM.Int8PtrTy); |
| // Optional instance methods |
| B.addNullPointer(IGM.Int8PtrTy); |
| // Optional class methods |
| B.addNullPointer(IGM.Int8PtrTy); |
| // Properties |
| B.addNullPointer(IGM.Int8PtrTy); |
| } |
| |
| void addSize() { |
| // The number of fields so far in words, plus 4 bytes for size and |
| // 4 bytes for flags. |
| B.addInt32(B.getNextOffsetFromGlobal().getValue() + 4 + 4); |
| } |
| |
| void addFlags() { |
| auto flags = ProtocolDescriptorFlags() |
| .withSwift(true) |
| .withClassConstraint(Protocol->requiresClass() |
| ? ProtocolClassConstraint::Class |
| : ProtocolClassConstraint::Any) |
| .withDispatchStrategy( |
| Lowering::TypeConverter::getProtocolDispatchStrategy(Protocol)) |
| .withSpecialProtocol(getSpecialProtocolID(Protocol)); |
| |
| if (DefaultWitnesses) |
| flags = flags.withResilient(true); |
| |
| B.addInt32(flags.getIntValue()); |
| } |
| |
| void addRequirements() { |
| auto &pi = IGM.getProtocolInfo(Protocol); |
| |
| B.addInt16(DefaultWitnesses |
| ? DefaultWitnesses->getMinimumWitnessTableSize() |
| : pi.getNumWitnesses()); |
| B.addInt16(pi.getNumWitnesses()); |
| |
| // If there are no entries, just add a null reference and return. |
| if (pi.getNumWitnesses() == 0) { |
| B.addInt(IGM.RelativeAddressTy, 0); |
| return; |
| } |
| |
| #ifndef NDEBUG |
| unsigned numDefaultWitnesses = 0; |
| #endif |
| |
| ConstantInitBuilder reqtBuilder(IGM); |
| auto reqtsArray = reqtBuilder.beginArray(IGM.ProtocolRequirementStructTy); |
| for (auto &entry : pi.getWitnessEntries()) { |
| auto reqt = reqtsArray.beginStruct(IGM.ProtocolRequirementStructTy); |
| |
| auto info = getRequirementInfo(entry); |
| |
| // Flags. |
| reqt.addInt32(info.Flags.getIntValue()); |
| |
| // Default implementation. |
| reqt.addRelativeAddressOrNull(info.DefaultImpl); |
| #ifndef NDEBUG |
| assert((info.DefaultImpl || numDefaultWitnesses == 0) && |
| "adding mandatory witness after defaulted witness"); |
| if (info.DefaultImpl) numDefaultWitnesses++; |
| #endif |
| |
| reqt.finishAndAddTo(reqtsArray); |
| } |
| |
| #ifndef NDEBUG |
| if (DefaultWitnesses) { |
| assert(numDefaultWitnesses |
| == DefaultWitnesses->getDefaultWitnessTableSize() && |
| "didn't use all the default witnesses!"); |
| } else { |
| assert(numDefaultWitnesses == 0); |
| } |
| #endif |
| |
| auto global = |
| reqtsArray.finishAndCreateGlobal("", Alignment(4), /*constant*/ true, |
| llvm::GlobalVariable::InternalLinkage); |
| global->setUnnamedAddr(llvm::GlobalVariable::UnnamedAddr::Global); |
| B.addRelativeOffset(IGM.Int32Ty, global); |
| } |
| |
| struct RequirementInfo { |
| ProtocolRequirementFlags Flags; |
| llvm::Constant *DefaultImpl; |
| }; |
| |
| /// Build the information which will go into a ProtocolRequirement entry. |
| RequirementInfo getRequirementInfo(const WitnessTableEntry &entry) { |
| using Flags = ProtocolRequirementFlags; |
| if (entry.isBase()) { |
| assert(entry.isOutOfLineBase()); |
| auto flags = Flags(Flags::Kind::BaseProtocol); |
| return { flags, nullptr }; |
| } |
| |
| if (entry.isAssociatedType()) { |
| auto flags = Flags(Flags::Kind::AssociatedTypeAccessFunction); |
| return { flags, nullptr }; |
| } |
| |
| if (entry.isAssociatedConformance()) { |
| auto flags = Flags(Flags::Kind::AssociatedConformanceAccessFunction); |
| return { flags, nullptr }; |
| } |
| |
| assert(entry.isFunction()); |
| auto func = entry.getFunction(); |
| |
| // Classify the function. |
| auto flags = getMethodDescriptorFlags<Flags>(func); |
| |
| // Look for a default witness. |
| llvm::Constant *defaultImpl = findDefaultWitness(func); |
| |
| return { flags, defaultImpl }; |
| } |
| |
| llvm::Constant *findDefaultWitness(AbstractFunctionDecl *func) { |
| if (!DefaultWitnesses) return nullptr; |
| |
| for (auto &entry : DefaultWitnesses->getResilientDefaultEntries()) { |
| if (entry.getRequirement().getDecl() != func) |
| continue; |
| return IGM.getAddrOfSILFunction(entry.getWitness(), NotForDefinition); |
| } |
| |
| return nullptr; |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// Emit global structures associated with the given protocol. This comprises |
| /// the protocol descriptor, and for ObjC interop, references to the descriptor |
| /// that the ObjC runtime uses for uniquing. |
| void IRGenModule::emitProtocolDecl(ProtocolDecl *protocol) { |
| // Emit remote reflection metadata for the protocol. |
| emitFieldMetadataRecord(protocol); |
| |
| // If the protocol is Objective-C-compatible, go through the path that |
| // produces an ObjC-compatible protocol_t. |
| if (protocol->isObjC()) { |
| // In JIT mode, we need to create protocol descriptors using the ObjC |
| // runtime in JITted code. |
| if (IRGen.Opts.UseJIT) |
| return; |
| |
| // Native ObjC protocols are emitted on-demand in ObjC and uniqued by the |
| // runtime; we don't need to try to emit a unique descriptor symbol for them. |
| if (protocol->hasClangNode()) |
| return; |
| |
| getObjCProtocolGlobalVars(protocol); |
| return; |
| } |
| |
| SILDefaultWitnessTable *defaultWitnesses = nullptr; |
| if (!protocol->hasFixedLayout()) |
| defaultWitnesses = getSILModule().lookUpDefaultWitnessTable(protocol); |
| |
| ConstantInitBuilder initBuilder(*this); |
| auto init = initBuilder.beginStruct(); |
| ProtocolDescriptorBuilder builder(*this, protocol, init, defaultWitnesses); |
| builder.layout(); |
| |
| auto var = cast<llvm::GlobalVariable>( |
| getAddrOfProtocolDescriptor(protocol, init.finishAndCreateFuture())); |
| var->setConstant(true); |
| } |
| |
| /// \brief Load a reference to the protocol descriptor for the given protocol. |
| /// |
| /// For Swift protocols, this is a constant reference to the protocol descriptor |
| /// symbol. |
| /// For ObjC protocols, descriptors are uniqued at runtime by the ObjC runtime. |
| /// We need to load the unique reference from a global variable fixed up at |
| /// startup. |
| llvm::Value *irgen::emitProtocolDescriptorRef(IRGenFunction &IGF, |
| ProtocolDecl *protocol) { |
| if (!protocol->isObjC()) |
| return IGF.IGM.getAddrOfProtocolDescriptor(protocol); |
| |
| auto refVar = IGF.IGM.getAddrOfObjCProtocolRef(protocol, NotForDefinition); |
| llvm::Value *val |
| = IGF.Builder.CreateLoad(refVar, IGF.IGM.getPointerAlignment()); |
| val = IGF.Builder.CreateBitCast(val, |
| IGF.IGM.ProtocolDescriptorStructTy->getPointerTo()); |
| return val; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Other metadata. |
| //===----------------------------------------------------------------------===// |
| |
| llvm::Value *irgen::emitMetatypeInstanceType(IRGenFunction &IGF, |
| llvm::Value *metatypeMetadata) { |
| // The instance type field of MetatypeMetadata is immediately after |
| // the isa field. |
| return emitInvariantLoadFromMetadataAtIndex(IGF, metatypeMetadata, 1, |
| IGF.IGM.TypeMetadataPtrTy); |
| } |