| //===--- 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/ASTMangler.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 "swift/Strings.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 "clang/AST/Decl.h" |
| #include "clang/AST/DeclObjC.h" |
| |
| #include "Address.h" |
| #include "Callee.h" |
| #include "ClassMetadataVisitor.h" |
| #include "ConstantBuilder.h" |
| #include "EnumMetadataVisitor.h" |
| #include "FixedTypeInfo.h" |
| #include "ForeignClassMetadataVisitor.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); |
| } |
| |
| llvm::Constant *IRGenModule::getAddrOfStringForTypeRef(StringRef str) { |
| return getAddrOfStringForTypeRef(SymbolicMangling{str,{}}); |
| } |
| |
| llvm::Constant *IRGenModule::getAddrOfStringForTypeRef( |
| const SymbolicMangling &mangling) { |
| // Create a symbol name for the symbolic mangling. This is used as the |
| // uniquing key both for ODR coalescing and within this TU. |
| IRGenMangler mangler; |
| std::string symbolName = |
| mangler.mangleSymbolNameForSymbolicMangling(mangling); |
| |
| // See if we emitted the constant already. |
| auto &entry = StringsForTypeRef[symbolName]; |
| if (entry.second) |
| return entry.second; |
| |
| ConstantInitBuilder B(*this); |
| auto S = B.beginStruct(); |
| S.setPacked(true); |
| |
| unsigned pos = 0; |
| for (auto &symbolic : mangling.SymbolicReferences) { |
| assert(symbolic.second >= pos |
| && "references should be ordered"); |
| if (symbolic.second != pos) { |
| // Emit the preceding literal chunk. |
| auto literalChunk = StringRef(mangling.String.data() + pos, |
| symbolic.second - pos); |
| assert(literalChunk.back() == '\1' && "should be prefixed with \\1"); |
| auto literal = llvm::ConstantDataArray::getString(getLLVMContext(), |
| literalChunk, |
| /*null*/ false); |
| S.add(literal); |
| } |
| |
| // The symbolic reference is to the type context descriptor of the |
| // referenced type. |
| // We currently only allow symbolic references to nominal type contexts. |
| auto nominal = cast<NominalTypeDecl>(symbolic.first); |
| S.addRelativeAddress( |
| getAddrOfTypeContextDescriptor(const_cast<NominalTypeDecl*>(nominal), |
| DontRequireMetadata)); |
| |
| pos = symbolic.second + 4; |
| } |
| |
| // Add the last literal bit, if any. |
| if (pos != mangling.String.size()) { |
| auto literalChunk = StringRef(mangling.String.data() + pos, |
| mangling.String.size() - pos); |
| auto literal = llvm::ConstantDataArray::getString(getLLVMContext(), |
| literalChunk, |
| /*null*/ false); |
| S.add(literal); |
| } |
| |
| // And a null terminator! |
| S.addInt(Int8Ty, 0); |
| |
| auto finished = S.finishAndCreateFuture(); |
| auto var = new llvm::GlobalVariable(Module, finished.getType(), |
| /*constant*/ true, |
| llvm::GlobalValue::LinkOnceODRLinkage, |
| nullptr, |
| symbolName); |
| var->setVisibility(llvm::GlobalValue::HiddenVisibility); |
| var->setAlignment(1); |
| setTrueConstGlobal(var); |
| var->setSection(getReflectionTypeRefSectionName()); |
| |
| finished.installInGlobal(var); |
| |
| // Drill down to the i8* at the beginning of the constant. |
| auto addr = llvm::ConstantExpr::getBitCast(var, Int8PtrTy); |
| entry = {var, addr}; |
| |
| return addr; |
| } |
| |
| // 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 *getTypeRef(IRGenModule &IGM, CanType type) { |
| IRGenMangler Mangler; |
| auto SymbolicName = Mangler.mangleTypeForReflection(IGM, type, |
| IGM.getSwiftModule(), |
| /*single-field box*/ false); |
| |
| return IGM.getAddrOfStringForTypeRef(SymbolicName); |
| } |
| |
| 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); |
| } |
| |
| /// 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, 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 *uniqueForeignTypeMetadataRef(IRGenFunction &IGF, |
| llvm::Value *candidate) { |
| 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; |
| } |
| |
| /// 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); |
| return uniqueForeignTypeMetadataRef(IGF, candidate); |
| } |
| |
| /// 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); |
| } |
| |
| // 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.empty() || |
| 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.emitGenericTypeMetadataAccessFunctionCall(accessor, genericArgs.Values); |
| |
| 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; |
| |
| // Any and AnyObject have singleton metadata. |
| if (type->isAny() || type->isAnyObject()) |
| return true; |
| |
| // 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; |
| } |
| |
| /// 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); |
| } |
| |
| /// 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(); |
| } |
| |
| TupleTypeFlags flags = |
| TupleTypeFlags().withNumElements(elements.size()); |
| llvm::Value *args[] = { |
| llvm::ConstantInt::get(IGF.IGM.SizeTy, flags.getIntValue()), |
| 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 ¶m) { |
| 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; |
| bool isEscaping = false; |
| switch (type->getRepresentation()) { |
| case FunctionTypeRepresentation::Swift: |
| metadataConvention = FunctionMetadataConvention::Swift; |
| isEscaping = !type->isNoEscape(); |
| 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) |
| .withEscaping(isEscaping); |
| |
| 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() |
| .withValueOwnership(flags.getValueOwnership()) |
| .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 0: |
| return IGF.IGM.getGetFunctionMetadata0Fn(); |
| |
| case 1: |
| return IGF.IGM.getGetFunctionMetadata1Fn(); |
| |
| case 2: |
| return IGF.IGM.getGetFunctionMetadata2Fn(); |
| |
| case 3: |
| return IGF.IGM.getGetFunctionMetadata3Fn(); |
| |
| default: |
| llvm_unreachable("supports only 1/2/3 parameter functions"); |
| } |
| }; |
| |
| switch (numParams) { |
| case 0: |
| case 1: |
| case 2: |
| case 3: { |
| if (!hasFlags) { |
| llvm::SmallVector<llvm::Value *, 8> arguments; |
| auto *metadataFn = constructSimpleCall(arguments); |
| auto *call = IGF.Builder.CreateCall(metadataFn, arguments); |
| call->setDoesNotThrow(); |
| return setLocal(CanType(type), call); |
| } |
| |
| // If function type has parameter flags, let's emit |
| // the most general function to retrieve them. |
| LLVM_FALLTHROUGH; |
| } |
| |
| default: |
| assert(!params.empty() && "0 parameter case is specialized!"); |
| |
| auto *const Int32Ptr = IGF.IGM.Int32Ty->getPointerTo(); |
| llvm::SmallVector<llvm::Value *, 8> arguments; |
| |
| arguments.push_back(flags); |
| |
| ConstantInitBuilder paramFlags(IGF.IGM); |
| auto flagsArr = paramFlags.beginArray(); |
| |
| auto arrayTy = |
| llvm::ArrayType::get(IGF.IGM.TypeMetadataPtrTy, numParams); |
| Address parameters = IGF.createAlloca( |
| arrayTy, IGF.IGM.getTypeMetadataAlignment(), "function-parameters"); |
| |
| IGF.Builder.CreateLifetimeStart(parameters, |
| IGF.IGM.getPointerSize() * numParams); |
| |
| collectParameters([&](unsigned i, llvm::Value *typeRef, |
| ParameterFlags flags) { |
| auto argPtr = IGF.Builder.CreateStructGEP(parameters, i, |
| IGF.IGM.getPointerSize()); |
| IGF.Builder.CreateStore(typeRef, argPtr); |
| if (i == 0) |
| arguments.push_back(argPtr.getAddress()); |
| |
| if (hasFlags) |
| flagsArr.addInt32(flags.getIntValue()); |
| }); |
| |
| 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)); |
| } |
| |
| 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; |
| |
| // Any and AnyObject have singleton metadata in the runtime. |
| llvm::Constant *singletonMetadata = nullptr; |
| if (type->isAny()) |
| singletonMetadata = IGF.IGM.getAnyExistentialMetadata(); |
| if (type->isAnyObject()) |
| singletonMetadata = IGF.IGM.getAnyObjectExistentialMetadata(); |
| |
| if (singletonMetadata) { |
| llvm::Constant *indices[] = { |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0), |
| llvm::ConstantInt::get(IGF.IGM.Int32Ty, 1) |
| }; |
| return llvm::ConstantExpr::getInBoundsGetElementPtr( |
| /*Ty=*/nullptr, singletonMetadata, indices); |
| } |
| |
| 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.CreateElementBitCast(addr, IGF.IGM.TypeMetadataPtrTy); |
| 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, |
| bool isReadNone) { |
| accessor->setDoesNotThrow(); |
| |
| // This function is logically 'readnone': the caller does not need |
| // to reason about any side effects or stores it might perform. |
| if (isReadNone) |
| 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); |
| } |
| |
| llvm::CallInst *IRGenFunction::emitGenericTypeMetadataAccessFunctionCall( |
| llvm::Function *accessFunction, |
| ArrayRef<llvm::Value *> args) { |
| |
| ArrayRef<llvm::Value *> callArgs; |
| llvm::Value *callArgsVec[NumDirectGenericTypeMetadataAccessFunctionArgs + 1]; |
| Address argsBuffer; |
| bool allocatedArgsBuffer = false; |
| if (args.size() > NumDirectGenericTypeMetadataAccessFunctionArgs) { |
| // Copy direct arguments. |
| for (unsigned i : range(NumDirectGenericTypeMetadataAccessFunctionArgs)) { |
| callArgsVec[i] = args[i]; |
| } |
| |
| // Allocate an array to pass the remaining arguments. Note that the |
| // buffer is allocated for the whole length so the callee can fill in |
| // the direct arguments and use the buffer. |
| auto argsBufferTy = llvm::ArrayType::get(IGM.Int8PtrTy, args.size()); |
| argsBuffer = createAlloca(argsBufferTy, IGM.getPointerAlignment()); |
| |
| // Mark the beginning of the array lifetime. |
| Builder.CreateLifetimeStart(argsBuffer, |
| IGM.getPointerSize() * args.size()); |
| allocatedArgsBuffer = true; |
| |
| // Fill in the non-direct arguments. |
| for (unsigned i : range(NumDirectGenericTypeMetadataAccessFunctionArgs, |
| args.size())) { |
| Address elt = Builder.CreateStructGEP(argsBuffer, i, |
| IGM.getPointerSize() * i); |
| auto *arg = |
| Builder.CreateBitCast(args[i], elt.getType()->getPointerElementType()); |
| Builder.CreateStore(arg, elt); |
| } |
| |
| // Fill in the buffer. |
| callArgsVec[NumDirectGenericTypeMetadataAccessFunctionArgs] = |
| Builder.CreateBitCast(argsBuffer.getAddress(), IGM.Int8PtrPtrTy); |
| callArgs = callArgsVec; |
| } else { |
| callArgs = args; |
| } |
| |
| auto call = Builder.CreateCall(accessFunction, callArgs); |
| call->setDoesNotThrow(); |
| call->addAttribute(llvm::AttributeList::FunctionIndex, |
| allocatedArgsBuffer |
| ? llvm::Attribute::InaccessibleMemOrArgMemOnly |
| : llvm::Attribute::ReadNone); |
| |
| // If we allocated a buffer for the arguments, end it's lifetime. |
| if (allocatedArgsBuffer) |
| Builder.CreateLifetimeEnd(argsBuffer, IGM.getPointerSize() * args.size()); |
| |
| return call; |
| } |
| |
| static llvm::Value *emitGenericMetadataAccessFunction(IRGenFunction &IGF, |
| NominalTypeDecl *nominal, |
| GenericArguments &genericArgs) { |
| llvm::Value *descriptor = |
| IGF.IGM.getAddrOfTypeContextDescriptor(nominal, RequireMetadata); |
| |
| // Collect input arguments to the generic metadata accessor, as laid out |
| // by the GenericArguments class. |
| unsigned argIdx = 0; |
| llvm::Argument *callerArgArray = nullptr; |
| for (auto &arg : IGF.CurFn->args()) { |
| // If this an argument passed directly, record it. |
| if (argIdx < NumDirectGenericTypeMetadataAccessFunctionArgs) { |
| genericArgs.Values.push_back(&arg); |
| ++argIdx; |
| continue; |
| } |
| |
| assert(!callerArgArray && "Too many arguments"); |
| callerArgArray = &arg; |
| } |
| |
| assert((!genericArgs.Values.empty() || |
| nominal->getGenericSignature()->areAllParamsConcrete()) && |
| "no generic args?!"); |
| |
| Address argsBuffer; |
| if (callerArgArray) { |
| // The caller provided a buffer with enough space for all of the arguments; |
| // use that. |
| argsBuffer = Address(callerArgArray, IGF.IGM.getPointerAlignment()); |
| } else { |
| // Allocate a buffer with enough storage for the arguments. |
| auto argsBufferTy = |
| llvm::StructType::get(IGF.IGM.LLVMContext, genericArgs.Types); |
| argsBuffer = IGF.createAlloca(argsBufferTy, |
| IGF.IGM.getPointerAlignment(), |
| "generic.arguments"); |
| IGF.Builder.CreateLifetimeStart(argsBuffer, |
| IGF.IGM.getPointerSize() * genericArgs.Values.size()); |
| } |
| |
| /// Store direct arguments into the buffer. |
| for (unsigned i = 0, e = genericArgs.Values.size(); i != e; ++i) { |
| Address elt; |
| if (callerArgArray) { |
| elt = IGF.Builder.CreateConstArrayGEP(argsBuffer, i, |
| IGF.IGM.getPointerSize()); |
| } else { |
| elt = IGF.Builder.CreateStructGEP(argsBuffer, i, |
| IGF.IGM.getPointerSize() * i); |
| } |
| |
| auto *arg = |
| IGF.Builder.CreateBitCast(genericArgs.Values[i], |
| elt.getType()->getPointerElementType()); |
| IGF.Builder.CreateStore(arg, elt); |
| } |
| |
| llvm::Value *arguments = |
| IGF.Builder.CreateBitCast(argsBuffer.getAddress(), IGF.IGM.Int8PtrTy); |
| |
| // Make the call. |
| auto result = IGF.Builder.CreateCall(IGF.IGM.getGetGenericMetadataFn(), |
| {descriptor, arguments}); |
| result->setDoesNotThrow(); |
| result->addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadOnly); |
| |
| // If we allocated the array ourselves, end its lifetime. |
| if (!callerArgArray) { |
| 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.requiresForeignTypeMetadata(type) |
| ? IGF.IGM.getAddrOfForeignTypeMetadataCandidate(type) |
| : IGF.IGM.getAddrOfTypeMetadata(type); |
| |
| // 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); |
| |
| // 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); |
| |
| bool isReadNone = |
| (genericArgs.Types.size() <= NumDirectGenericTypeMetadataAccessFunctionArgs); |
| |
| emitLazyCacheAccessFunction(IGM, accessor, /*cacheVariable=*/nullptr, |
| [&](IRGenFunction &IGF) -> llvm::Value * { |
| return emitGenericMetadataAccessFunction( |
| IGF, nominal, genericArgs); |
| }, |
| isReadNone); |
| |
| 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 (theDecl->isGenericContext()) { |
| return getGenericTypeMetadataAccessFunction(IGM, theDecl, shouldDefine); |
| } |
| |
| CanType declaredType = theDecl->getDeclaredType()->getCanonicalType(); |
| return getTypeMetadataAccessFunction(IGM, declaredType, shouldDefine); |
| } |
| |
| /// 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); |
| } |
| |
| /// 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).getOptionalObjectType()) { |
| 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); |
| |
| return IGF.emitGenericTypeMetadataAccessFunctionCall(accessor, args); |
| } |
| |
| // 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(); |
| } |
| |
| TupleTypeFlags flags = |
| TupleTypeFlags().withNumElements(elements.size()); |
| |
| llvm::Value *args[] = { |
| llvm::ConstantInt::get(IGF.IGM.SizeTy, flags.getIntValue()), |
| 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: |
| if (isa<ExistentialMetatypeType>(type)) { |
| return emitFromTypeMetadata(type); |
| } |
| // Otherwise, this is a metatype that looks like a pointer. |
| LLVM_FALLTHROUGH; |
| 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 ReferenceOwnership::Strong: |
| llvm_unreachable("shouldn't be a ReferenceStorageType"); |
| case ReferenceOwnership::Weak: |
| referent = type.getReferentType().getOptionalObjectType(); |
| break; |
| case ReferenceOwnership::Unmanaged: |
| case ReferenceOwnership::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() == ReferenceOwnership::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() == ReferenceOwnership::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 = [&] { |
| auto accessor = dyn_cast<AccessorDecl>(fn); |
| if (!accessor) return Flags::Kind::Method; |
| switch (accessor->getAccessorKind()) { |
| 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 ContextDescriptorBuilderBase { |
| protected: |
| Impl &asImpl() { return *static_cast<Impl*>(this); } |
| IRGenModule &IGM; |
| private: |
| ConstantInitBuilder InitBuilder; |
| protected: |
| ConstantStructBuilder B; |
| Optional<ConstantAggregateBuilderBase::PlaceholderPosition> |
| GenericParamCount, |
| GenericRequirementCount, |
| GenericKeyArgumentCount, |
| GenericExtraArgumentCount; |
| unsigned NumGenericKeyArguments = 0; |
| unsigned NumGenericExtraArguments = 0; |
| |
| ContextDescriptorBuilderBase(IRGenModule &IGM) |
| : IGM(IGM), InitBuilder(IGM), B(InitBuilder.beginStruct()) { |
| B.setPacked(true); |
| } |
| |
| public: |
| void layout() { |
| asImpl().addFlags(); |
| asImpl().addParent(); |
| } |
| |
| void addFlags() { |
| B.addInt32( |
| ContextDescriptorFlags(asImpl().getContextKind(), |
| asImpl().getGenericSignature() != nullptr, |
| asImpl().isUniqueDescriptor(), |
| asImpl().getVersion(), |
| asImpl().getKindSpecificFlags()) |
| .getIntValue()); |
| } |
| |
| void addParent() { |
| ConstantReference parent = asImpl().getParent(); |
| if (parent.getValue()) { |
| B.addRelativeAddress(parent); |
| } else { |
| B.addInt32(0); // null offset |
| } |
| } |
| |
| void addGenericSignature() { |
| if (!asImpl().getGenericSignature()) |
| return; |
| |
| asImpl().addGenericParametersHeader(); |
| asImpl().addGenericParameters(); |
| asImpl().addGenericRequirements(); |
| asImpl().finishGenericParameters(); |
| } |
| |
| void addGenericParametersHeader() { |
| // Drop placeholders for the counts. We'll fill these in when we emit |
| // the related sections. |
| GenericParamCount = B.addPlaceholderWithSize(IGM.Int16Ty); |
| GenericRequirementCount = B.addPlaceholderWithSize(IGM.Int16Ty); |
| GenericKeyArgumentCount = B.addPlaceholderWithSize(IGM.Int16Ty); |
| GenericExtraArgumentCount = B.addPlaceholderWithSize(IGM.Int16Ty); |
| } |
| |
| void addGenericParameters() { |
| GenericSignature *sig = asImpl().getGenericSignature(); |
| assert(sig); |
| auto canSig = sig->getCanonicalSignature(); |
| |
| for (auto param : canSig->getGenericParams()) { |
| // Currently, there are only type parameters. The parameter is a key |
| // argument if it hasn't been grounded by a same-type constraint. |
| asImpl().addGenericParameter(GenericParamKind::Type, |
| /*key argument*/ !canSig->isConcreteType(param), |
| /*extra argument*/ false); |
| } |
| |
| // Pad the structure up to four bytes for the following requirements. |
| unsigned padding = (unsigned) -canSig->getGenericParams().size() & 3; |
| for (unsigned i = 0; i < padding; ++i) |
| B.addInt(IGM.Int8Ty, 0); |
| |
| // Fill in the parameter count. |
| assert(canSig->getGenericParams().size() <= UINT16_MAX |
| && "way too generic"); |
| B.fillPlaceholderWithInt(*GenericParamCount, IGM.Int16Ty, |
| canSig->getGenericParams().size()); |
| } |
| |
| void addGenericParameter(GenericParamKind kind, |
| bool isKeyArgument, bool isExtraArgument) { |
| if (isKeyArgument) |
| ++NumGenericKeyArguments; |
| if (isExtraArgument) |
| ++NumGenericExtraArguments; |
| |
| B.addInt(IGM.Int8Ty, |
| GenericParamDescriptor(kind, isKeyArgument, isExtraArgument) |
| .getIntValue()); |
| } |
| |
| void addGenericRequirements() { |
| auto metadata = |
| irgen::addGenericRequirements(IGM, B, |
| asImpl().getGenericSignature(), |
| asImpl().getGenericSignature()->getRequirements()); |
| |
| // Fill in the final requirement count. |
| assert(metadata.NumRequirements <= UINT16_MAX |
| && "way too generic"); |
| B.fillPlaceholderWithInt(*GenericRequirementCount, IGM.Int16Ty, |
| metadata.NumRequirements); |
| NumGenericKeyArguments += metadata.NumGenericKeyArguments; |
| NumGenericExtraArguments += metadata.NumGenericExtraArguments; |
| } |
| |
| void finishGenericParameters() { |
| assert(NumGenericKeyArguments <= UINT16_MAX |
| && NumGenericExtraArguments <= UINT16_MAX |
| && "way too generic"); |
| B.fillPlaceholderWithInt(*GenericKeyArgumentCount, IGM.Int16Ty, |
| NumGenericKeyArguments); |
| B.fillPlaceholderWithInt(*GenericExtraArgumentCount, IGM.Int16Ty, |
| NumGenericExtraArguments); |
| } |
| |
| uint8_t getVersion() { |
| return 0; |
| } |
| |
| uint16_t getKindSpecificFlags() { |
| return 0; |
| } |
| |
| // Subclasses should provide: |
| // |
| // bool isUniqueDescriptor(); |
| // llvm::Constant *getParent(); |
| // ContextDescriptorKind getContextKind(); |
| // GenericSignature *getGenericSignature(); |
| // void emit(); |
| }; |
| |
| class ModuleContextDescriptorBuilder |
| : public ContextDescriptorBuilderBase<ModuleContextDescriptorBuilder> { |
| using super = ContextDescriptorBuilderBase; |
| |
| ModuleDecl *M; |
| |
| public: |
| ModuleContextDescriptorBuilder(IRGenModule &IGM, ModuleDecl *M) |
| : super(IGM), M(M) |
| {} |
| |
| void layout() { |
| super::layout(); |
| addName(); |
| } |
| |
| void addName() { |
| B.addRelativeAddress(IGM.getAddrOfGlobalString(M->getName().str(), |
| /*willBeRelativelyAddressed*/ true)); |
| } |
| |
| bool isUniqueDescriptor() { |
| return false; |
| } |
| |
| ConstantReference getParent() { |
| return {nullptr, ConstantReference::Direct}; |
| } |
| |
| ContextDescriptorKind getContextKind() { |
| return ContextDescriptorKind::Module; |
| } |
| |
| GenericSignature *getGenericSignature() { |
| return nullptr; |
| } |
| |
| void emit() { |
| asImpl().layout(); |
| |
| auto addr = IGM.getAddrOfModuleContextDescriptor(M, |
| B.finishAndCreateFuture()); |
| auto var = cast<llvm::GlobalVariable>(addr); |
| |
| var->setConstant(true); |
| IGM.setTrueConstGlobal(var); |
| } |
| }; |
| |
| class ExtensionContextDescriptorBuilder |
| : public ContextDescriptorBuilderBase<ExtensionContextDescriptorBuilder> { |
| |
| using super = ContextDescriptorBuilderBase; |
| |
| ExtensionDecl *E; |
| |
| public: |
| ExtensionContextDescriptorBuilder(IRGenModule &IGM, ExtensionDecl *E) |
| : super(IGM), E(E) |
| {} |
| |
| void layout() { |
| super::layout(); |
| addExtendedContext(); |
| addGenericSignature(); |
| } |
| |
| void addExtendedContext() { |
| auto string = getTypeRef(IGM, |
| E->getSelfInterfaceType()->getCanonicalType()); |
| B.addRelativeAddress(string); |
| } |
| |
| ConstantReference getParent() { |
| return {IGM.getAddrOfModuleContextDescriptor(E->getParentModule()), |
| ConstantReference::Direct}; |
| } |
| |
| bool isUniqueDescriptor() { |
| // Extensions generated by the Clang importer will be emitted into any |
| // binary that uses the Clang module. Otherwise, we can guarantee that |
| // an extension (and any of its possible sub-contexts) belong to one |
| // translation unit. |
| return !isa<ClangModuleUnit>(E->getModuleScopeContext()); |
| } |
| |
| ContextDescriptorKind getContextKind() { |
| return ContextDescriptorKind::Extension; |
| } |
| |
| GenericSignature *getGenericSignature() { |
| return E->getGenericSignature(); |
| } |
| |
| void emit() { |
| asImpl().layout(); |
| |
| auto addr = IGM.getAddrOfExtensionContextDescriptor(E, |
| B.finishAndCreateFuture()); |
| auto var = cast<llvm::GlobalVariable>(addr); |
| |
| var->setConstant(true); |
| IGM.setTrueConstGlobal(var); |
| } |
| }; |
| |
| class AnonymousContextDescriptorBuilder |
| : public ContextDescriptorBuilderBase<AnonymousContextDescriptorBuilder> { |
| |
| using super = ContextDescriptorBuilderBase; |
| |
| DeclContext *DC; |
| |
| public: |
| AnonymousContextDescriptorBuilder(IRGenModule &IGM, DeclContext *DC) |
| : super(IGM), DC(DC) |
| { |
| } |
| |
| void layout() { |
| super::layout(); |
| } |
| |
| ConstantReference getParent() { |
| return {IGM.getAddrOfModuleContextDescriptor(DC->getParentModule()), |
| ConstantReference::Direct}; |
| } |
| |
| ContextDescriptorKind getContextKind() { |
| return ContextDescriptorKind::Anonymous; |
| } |
| |
| GenericSignature *getGenericSignature() { |
| return nullptr; |
| } |
| |
| bool isUniqueDescriptor() { |
| return true; |
| } |
| |
| void emit() { |
| asImpl().layout(); |
| auto addr = IGM.getAddrOfAnonymousContextDescriptor(DC, |
| B.finishAndCreateFuture()); |
| auto var = cast<llvm::GlobalVariable>(addr); |
| |
| var->setConstant(true); |
| IGM.setTrueConstGlobal(var); |
| } |
| }; |
| |
| template<class Impl> |
| class TypeContextDescriptorBuilderBase |
| : public ContextDescriptorBuilderBase<Impl> { |
| |
| using super = ContextDescriptorBuilderBase<Impl>; |
| |
| protected: |
| NominalTypeDecl *Type; |
| RequireMetadata_t HasMetadata; |
| |
| using super::IGM; |
| using super::B; |
| using super::asImpl; |
| |
| public: |
| using super::addGenericSignature; |
| |
| TypeContextDescriptorBuilderBase(IRGenModule &IGM, NominalTypeDecl *Type, |
| RequireMetadata_t requireMetadata) |
| : super(IGM), Type(Type), |
| HasMetadata(requireMetadata) |
| {} |
| |
| void layout() { |
| super::layout(); |
| asImpl().addName(); |
| asImpl().addAccessFunction(); |
| // ABI TODO: layout info should be superseded by remote mirror metadata |
| asImpl().addLayoutInfo(); |
| asImpl().addGenericSignature(); |
| } |
| |
| void addName() { |
| StringRef name; |
| |
| // Try to use the Clang name if there is one. |
| if (auto namedClangDecl = |
| Mangle::ASTMangler::getClangDeclForMangling(Type)) { |
| name = namedClangDecl->getName(); |
| } else { |
| name = Type->getName().str(); |
| } |
| |
| auto nameStr = IGM.getAddrOfGlobalString(name, |
| /*willBeRelativelyAddressed*/ true); |
| B.addRelativeAddress(nameStr); |
| } |
| |
| void addAccessFunction() { |
| // Don't emit the access function if we're only lazily emitting the |
| // context descriptor. |
| if (!HasMetadata) { |
| B.addInt32(0); |
| return; |
| } |
| |
| llvm::Constant *accessFn = |
| getRequiredTypeMetadataAccessFunction(IGM, Type, NotForDefinition); |
| B.addRelativeAddressOrNull(accessFn); |
| } |
| |
| ConstantReference getParent() { |
| return IGM.getAddrOfParentContextDescriptor(Type); |
| } |
| |
| GenericSignature *getGenericSignature() { |
| return Type->getGenericSignature(); |
| } |
| |
| /// Fill in the fields of a TypeGenericContextDescriptorHeader. |
| void addGenericParametersHeader() { |
| asImpl().addMetadataInstantiationCache(); |
| |
| asImpl().addMetadataInstantiationPattern(); |
| |
| super::addGenericParametersHeader(); |
| } |
| |
| void addMetadataInstantiationPattern() { |
| if (!HasMetadata) { |
| B.addInt32(0); |
| return; |
| } |
| |
| auto pattern = IGM.getAddrOfTypeMetadataPattern(Type); |
| B.addRelativeAddress(pattern); |
| } |
| |
| void addMetadataInstantiationCache() { |
| if (!HasMetadata) { |
| B.addInt32(0); |
| return; |
| } |
| |
| auto cache = |
| IGM.getAddrOfTypeMetadataInstantiationCache(Type, NotForDefinition); |
| B.addRelativeAddress(cache); |
| } |
| |
| bool isUniqueDescriptor() { |
| return !isa<ClangModuleUnit>(Type->getModuleScopeContext()); |
| } |
| |
| llvm::Constant *emit() { |
| asImpl().layout(); |
| auto addr = IGM.getAddrOfTypeContextDescriptor(Type, HasMetadata, |
| B.finishAndCreateFuture()); |
| auto var = cast<llvm::GlobalVariable>(addr); |
| |
| var->setConstant(true); |
| IGM.setTrueConstGlobal(var); |
| return var; |
| } |
| |
| /// Flags to indicate Clang-imported declarations so we mangle them |
| /// consistently at runtime. |
| void getClangImportedFlags(TypeContextDescriptorFlags &flags) const { |
| auto clangDecl = Mangle::ASTMangler::getClangDeclForMangling(Type); |
| if (!clangDecl) |
| return; |
| |
| if (isa<clang::TagDecl>(clangDecl)) { |
| flags.setIsCTag(true); |
| return; |
| } |
| |
| if (isa<clang::TypedefNameDecl>(clangDecl) |
| || isa<clang::ObjCCompatibleAliasDecl>(clangDecl)) { |
| flags.setIsCTypedef(true); |
| return; |
| } |
| |
| return; |
| } |
| |
| // Subclasses should provide: |
| // ContextDescriptorKind getContextKind(); |
| // void addLayoutInfo(); // ABI TODO: should be superseded |
| }; |
| |
| /// Build a doubly-null-terminated list of field names. |
| /// |
| /// ABI TODO: This should be unnecessary when the fields that use it are |
| /// superseded. |
| 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. |
| /// |
| /// ABI TODO: This should be unnecessary when the fields that use it are |
| /// superseded. |
| static void addFieldTypes(IRGenModule &IGM, ArrayRef<CanType> fieldTypes) { |
| IGM.addFieldTypes(fieldTypes); |
| } |
| |
| /// Build a field type accessor for stored properties. |
| /// |
| /// ABI TODO: This should be unnecessary when the fields that use it are |
| /// superseded. |
| static void |
| addFieldTypes(IRGenModule &IGM, NominalTypeDecl *type, |
| NominalTypeDecl::StoredPropertyRange storedProperties) { |
| SmallVector<CanType, 4> types; |
| for (VarDecl *prop : storedProperties) { |
| auto propertyType = type->mapTypeIntoContext(prop->getInterfaceType()) |
| ->getCanonicalType(); |
| types.push_back(propertyType); |
| } |
| |
| addFieldTypes(IGM, types); |
| } |
| |
| /// Build a case type accessor for enum payloads. |
| /// |
| /// ABI TODO: This should be unnecessary when the fields that use it are |
| /// superseded. |
| static void addFieldTypes(IRGenModule &IGM, |
| ArrayRef<EnumImplStrategy::Element> enumElements) { |
| SmallVector<CanType, 4> types; |
| |
| for (auto &elt : enumElements) { |
| auto caseType = elt.decl->getParentEnum()->mapTypeIntoContext( |
| elt.decl->getArgumentInterfaceType()) |
| ->getCanonicalType(); |
| types.push_back(caseType); |
| } |
| |
| addFieldTypes(IGM, types); |
| } |
| |
| |
| class StructContextDescriptorBuilder |
| : public TypeContextDescriptorBuilderBase<StructContextDescriptorBuilder> |
| { |
| using super = TypeContextDescriptorBuilderBase; |
| |
| StructDecl *getType() { |
| return cast<StructDecl>(Type); |
| } |
| |
| Size FieldVectorOffset; |
| |
| public: |
| StructContextDescriptorBuilder(IRGenModule &IGM, StructDecl *Type, |
| RequireMetadata_t requireMetadata) |
| : super(IGM, Type, requireMetadata) |
| { |
| auto &layout = IGM.getMetadataLayout(getType()); |
| FieldVectorOffset = layout.getFieldOffsetVectorOffset().getStatic(); |
| } |
| |
| ContextDescriptorKind getContextKind() { |
| return ContextDescriptorKind::Struct; |
| } |
| |
| void addLayoutInfo() { |
| auto properties = getType()->getStoredProperties(); |
| |
| // uint32_t NumFields; |
| B.addInt32(std::distance(properties.begin(), properties.end())); |
| |
| // uint32_t FieldOffsetVectorOffset; |
| B.addInt32(FieldVectorOffset / IGM.getPointerSize()); |
| |
| addFieldTypes(IGM, getType(), properties); |
| } |
| |
| uint16_t getKindSpecificFlags() { |
| TypeContextDescriptorFlags flags; |
| |
| flags.setIsReflectable(true); // struct always reflectable |
| |
| getClangImportedFlags(flags); |
| return flags.getOpaqueValue(); |
| } |
| }; |
| |
| class EnumContextDescriptorBuilder |
| : public TypeContextDescriptorBuilderBase<EnumContextDescriptorBuilder> |
| { |
| using super = TypeContextDescriptorBuilderBase; |
| |
| EnumDecl *getType() { |
| return cast<EnumDecl>(Type); |
| } |
| |
| Size PayloadSizeOffset; |
| const EnumImplStrategy &Strategy; |
| |
| public: |
| EnumContextDescriptorBuilder(IRGenModule &IGM, EnumDecl *Type, |
| RequireMetadata_t requireMetadata) |
| : super(IGM, Type, requireMetadata), |
| Strategy(getEnumImplStrategy(IGM, |
| getType()->getDeclaredTypeInContext()->getCanonicalType())) |
| { |
| auto &layout = IGM.getMetadataLayout(getType()); |
| if (layout.hasPayloadSizeOffset()) |
| PayloadSizeOffset = layout.getPayloadSizeOffset().getStatic(); |
| } |
| |
| ContextDescriptorKind getContextKind() { |
| return ContextDescriptorKind::Enum; |
| } |
| |
| void addLayoutInfo() { |
| // # 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"); |
| |
| // uint32_t NumPayloadCasesAndPayloadSizeOffset; |
| B.addInt32(numPayloads | (PayloadSizeOffsetInWords << 24)); |
| |
| // uint32_t NumEmptyCases; |
| B.addInt32(Strategy.getElementsWithNoPayload().size()); |
| |
| addFieldTypes(IGM, Strategy.getElementsWithPayload()); |
| } |
| |
| uint16_t getKindSpecificFlags() { |
| TypeContextDescriptorFlags flags; |
| |
| flags.setIsReflectable(Strategy.isReflectable()); |
| |
| getClangImportedFlags(flags); |
| return flags.getOpaqueValue(); |
| } |
| }; |
| |
| class ClassContextDescriptorBuilder |
| : public TypeContextDescriptorBuilderBase<ClassContextDescriptorBuilder>, |
| public SILVTableVisitor<ClassContextDescriptorBuilder> |
| { |
| using super = TypeContextDescriptorBuilderBase; |
| |
| ClassDecl *getType() { |
| return cast<ClassDecl>(Type); |
| } |
| |
| // Non-null unless the type is foreign. |
| ClassMetadataLayout *MetadataLayout = nullptr; |
| |
| Optional<TypeEntityReference> SuperClassRef; |
| |
| SILVTable *VTable = nullptr; |
| unsigned VTableSize = 0; |
| |
| public: |
| ClassContextDescriptorBuilder(IRGenModule &IGM, ClassDecl *Type, |
| RequireMetadata_t requireMetadata) |
| : super(IGM, Type, requireMetadata) |
| { |
| if (getType()->isForeign()) return; |
| |
| MetadataLayout = &IGM.getClassMetadataLayout(Type); |
| |
| if (auto superclassDecl = getType()->getSuperclassDecl()) { |
| SuperClassRef = IGM.getTypeEntityReference(superclassDecl); |
| } |
| |
| VTableSize = MetadataLayout->getVTableSize(); |
| if (VTableSize) { |
| VTable = IGM.getSILModule().lookUpVTable(getType()); |
| } |
| } |
| |
| void layout() { |
| super::layout(); |
| addVTable(); |
| } |
| |
| ContextDescriptorKind getContextKind() { |
| return ContextDescriptorKind::Class; |
| } |
| |
| uint16_t getKindSpecificFlags() { |
| TypeContextDescriptorFlags flags; |
| |
| // Classes are always reflectable. |
| flags.setIsReflectable(true); |
| |
| if (!getType()->isForeign()) { |
| if (MetadataLayout->areImmediateMembersNegative()) |
| flags.class_setAreImmediateMembersNegative(true); |
| |
| if (VTableSize != 0) |
| flags.class_setHasVTable(true); |
| |
| if (MetadataLayout->hasResilientSuperclass()) |
| flags.class_setHasResilientSuperclass(true); |
| } |
| |
| if (SuperClassRef) { |
| flags.class_setSuperclassReferenceKind(SuperClassRef->getKind()); |
| } |
| |
| getClangImportedFlags(flags); |
| |
| return flags.getOpaqueValue(); |
| } |
| |
| Size getFieldVectorOffset() { |
| if (!MetadataLayout) return Size(0); |
| return (MetadataLayout->hasResilientSuperclass() |
| ? MetadataLayout->getRelativeFieldOffsetVectorOffset() |
| : MetadataLayout->getStaticFieldOffsetVectorOffset()); |
| } |
| |
| void addVTable() { |
| if (VTableSize == 0) |
| return; |
| |
| auto offset = MetadataLayout->hasResilientSuperclass() |
| ? MetadataLayout->getRelativeVTableOffset() |
| : MetadataLayout->getStaticVTableOffset(); |
| B.addInt32(offset / IGM.getPointerSize()); |
| B.addInt32(VTableSize); |
| |
| addVTableEntries(getType()); |
| } |
| |
| 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() == getType()) { |
| 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 addLayoutInfo() { |
| auto properties = getType()->getStoredProperties(); |
| |
| // RelativeDirectPointer<const void, /*nullable*/ true> SuperClass; |
| if (SuperClassRef) { |
| B.addRelativeAddress(SuperClassRef->getValue()); |
| } else { |
| B.addInt32(0); |
| } |
| |
| // union { |
| // uint32_t MetadataNegativeSizeInWords; |
| // RelativeDirectPointer<StoredClassMetadataBounds> |
| // ResilientMetadataBounds; |
| // }; |
| if (!MetadataLayout) { |
| // FIXME: do something meaningful for foreign classes? |
| B.addInt32(0); |
| } else if (!MetadataLayout->hasResilientSuperclass()) { |
| B.addInt32(MetadataLayout->getSize().AddressPoint |
| / IGM.getPointerSize()); |
| } else { |
| B.addRelativeAddress( |
| IGM.getAddrOfClassMetadataBounds(getType(), NotForDefinition)); |
| } |
| |
| // union { |
| // uint32_t MetadataPositiveSizeInWords; |
| // }; |
| if (!MetadataLayout) { |
| // FIXME: do something meaningful for foreign classes? |
| B.addInt32(0); |
| } else if (!MetadataLayout->hasResilientSuperclass()) { |
| B.addInt32(MetadataLayout->getSize().getOffsetToEnd() |
| / IGM.getPointerSize()); |
| } else { |
| B.addInt32(0); // currently unused |
| } |
| |
| // uint32_t NumImmediateMembers; |
| auto numImmediateMembers = |
| (MetadataLayout ? MetadataLayout->getNumImmediateMembers() : 0); |
| B.addInt32(numImmediateMembers); |
| |
| // uint32_t NumFields; |
| B.addInt32(std::distance(properties.begin(), properties.end())); |
| |
| // uint32_t FieldOffsetVectorOffset; |
| B.addInt32(getFieldVectorOffset() / IGM.getPointerSize()); |
| |
| addFieldTypes(IGM, getType(), properties); |
| } |
| }; |
| } // end anonymous namespace |
| |
| static void eraseExistingTypeContextDescriptor(IRGenModule &IGM, |
| NominalTypeDecl *type) { |
| // We may have emitted a partial type context descriptor with some empty |
| // fields, and then later discovered we're emitting complete metadata. |
| // Remove existing definitions of the type context so that we can regenerate |
| // a complete descriptor. |
| auto entity = IGM.getAddrOfTypeContextDescriptor(type, DontRequireMetadata); |
| entity = entity->stripPointerCasts(); |
| auto existingContext = dyn_cast<llvm::GlobalVariable>(entity); |
| if (existingContext && !existingContext->isDeclaration()) { |
| existingContext->setInitializer(nullptr); |
| } |
| } |
| |
| void irgen::emitLazyTypeContextDescriptor(IRGenModule &IGM, |
| NominalTypeDecl *type, |
| RequireMetadata_t requireMetadata) { |
| eraseExistingTypeContextDescriptor(IGM, type); |
| |
| if (auto sd = dyn_cast<StructDecl>(type)) { |
| StructContextDescriptorBuilder(IGM, sd, requireMetadata).emit(); |
| } else if (auto ed = dyn_cast<EnumDecl>(type)) { |
| EnumContextDescriptorBuilder(IGM, ed, requireMetadata).emit(); |
| } else if (auto cd = dyn_cast<ClassDecl>(type)) { |
| ClassContextDescriptorBuilder(IGM, cd, requireMetadata).emit(); |
| } else { |
| llvm_unreachable("type does not have a context descriptor"); |
| } |
| } |
| |
| void irgen::emitLazyTypeMetadata(IRGenModule &IGM, NominalTypeDecl *type) { |
| eraseExistingTypeContextDescriptor(IGM, type); |
| |
| if (auto sd = dyn_cast<StructDecl>(type)) { |
| return emitStructMetadata(IGM, sd); |
| } else if (auto ed = dyn_cast<EnumDecl>(type)) { |
| emitEnumMetadata(IGM, ed); |
| } else if (auto pd = dyn_cast<ProtocolDecl>(type)) { |
| IGM.emitProtocolDecl(pd); |
| } else { |
| llvm_unreachable("should not have enqueued a class decl here!"); |
| } |
| |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfSharedContextDescriptor(LinkEntity entity, |
| ConstantInit definition, |
| llvm::function_ref<void()> emit) { |
| if (!definition) { |
| // Generate the definition if it hasn't been generated yet. |
| auto existing = GlobalVars.find(entity); |
| if (existing == GlobalVars.end() || |
| !existing->second |
| || cast<llvm::GlobalValue>(existing->second)->isDeclaration()) { |
| |
| // In some cases we have multiple declarations in the AST that end up |
| // with the same context mangling (a clang module and its overlay, |
| // equivalent extensions, etc.). These can share a context descriptor |
| // at runtime. |
| auto mangledName = entity.mangleAsString(); |
| if (auto otherDefinition = Module.getGlobalVariable(mangledName)) { |
| GlobalVars.insert({entity, otherDefinition}); |
| return otherDefinition; |
| } |
| |
| // Otherwise, emit the descriptor. |
| emit(); |
| } |
| } |
| |
| return getAddrOfLLVMVariable(entity, Alignment(4), |
| definition, |
| TypeContextDescriptorTy, |
| DebugTypeInfo()); |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfModuleContextDescriptor(ModuleDecl *D, |
| ConstantInit definition) { |
| auto entity = LinkEntity::forModuleDescriptor(D); |
| return getAddrOfSharedContextDescriptor(entity, definition, |
| [&]{ ModuleContextDescriptorBuilder(*this, D).emit(); }); |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfObjCModuleContextDescriptor() { |
| if (!ObjCModule) |
| ObjCModule = ModuleDecl::create( |
| Context.getIdentifier(MANGLING_MODULE_OBJC), |
| Context); |
| return getAddrOfModuleContextDescriptor(ObjCModule); |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfClangImporterModuleContextDescriptor() { |
| if (!ClangImporterModule) |
| ClangImporterModule = ModuleDecl::create( |
| Context.getIdentifier(MANGLING_MODULE_CLANG_IMPORTER), |
| Context); |
| return getAddrOfModuleContextDescriptor(ClangImporterModule); |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfExtensionContextDescriptor(ExtensionDecl *ED, |
| ConstantInit definition) { |
| auto entity = LinkEntity::forExtensionDescriptor(ED); |
| return getAddrOfSharedContextDescriptor(entity, definition, |
| [&]{ ExtensionContextDescriptorBuilder(*this, ED).emit(); }); |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfAnonymousContextDescriptor(DeclContext *DC, |
| ConstantInit definition) { |
| auto entity = LinkEntity::forAnonymousDescriptor(DC); |
| return getAddrOfSharedContextDescriptor(entity, definition, |
| [&]{ AnonymousContextDescriptorBuilder(*this, DC).emit(); }); |
| } |
| |
| void IRGenModule::addFieldTypes(ArrayRef<CanType> fieldTypes) { |
| IRGen.addFieldTypes(fieldTypes, this); |
| } |
| |
| /*****************************************************************************/ |
| /** 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; |
| |
| struct FillOp { |
| CanType Type; |
| Optional<ProtocolConformanceRef> Conformance; |
| }; |
| |
| SmallVector<FillOp, 8> FillOps; |
| |
| protected: |
| using 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. Implies HasDependentMetadata. |
| bool HasDependentVWT = false; |
| |
| template <class... T> |
| GenericMetadataBuilderBase(IRGenModule &IGM, T &&...args) |
| : super(IGM, std::forward<T>(args)...) {} |
| |
| /// Emit the instantiation cache variable for the template. |
| void emitInstantiationCache() { |
| auto cache = cast<llvm::GlobalVariable>( |
| IGM.getAddrOfTypeMetadataInstantiationCache(Target, ForDefinition)); |
| auto init = |
| llvm::ConstantAggregateZero::get(cache->getValueType()); |
| cache->setInitializer(init); |
| } |
| |
| /// Emit the create function for the template. |
| void emitInstantiationFunction() { |
| // using MetadataInstantiator = |
| // Metadata *(TypeContextDescriptor *type, |
| // const void * const *arguments, |
| // const GenericMetadataPattern *pattern); |
| llvm::Function *f = |
| IGM.getAddrOfTypeMetadataInstantiationFunction(Target, ForDefinition); |
| 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 *descriptor = params.claimNext(); |
| llvm::Value *args = params.claimNext(); |
| llvm::Value *templatePointer = params.claimNext(); |
| |
| // Bind the generic arguments. |
| if (Target->isGenericContext()) { |
| Address argsArray(args, IGM.getPointerAlignment()); |
| emitPolymorphicParametersFromArray(IGF, Target, argsArray); |
| } |
| |
| // Allocate the metadata. |
| llvm::Value *metadata = |
| asImpl().emitAllocateMetadata(IGF, descriptor, args, templatePointer); |
| |
| // Execute the fill ops. Cast the parameters to word pointers because the |
| // fill indexes are word-indexed. |
| auto *metadataWords = |
| IGF.Builder.CreateBitCast(metadata, IGM.Int8PtrPtrTy); |
| |
| auto genericReqtOffset = IGM.getNominalMetadataLayout(Target) |
| .getGenericRequirementsOffset(IGF); |
| |
| 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 = IGF.emitAddressAtOffset(metadataWords, genericReqtOffset, |
| IGM.Int8PtrTy, |
| IGM.getPointerAlignment()); |
| |
| value = IGF.Builder.CreateBitCast(value, IGM.Int8PtrTy); |
| IGF.Builder.CreateStore(value, dest); |
| |
| genericReqtOffset = genericReqtOffset.offsetBy( |
| IGF, IGM.getPointerSize()); |
| } |
| |
| IGF.Builder.CreateRet(metadata); |
| } |
| |
| void emitCompletionFunction() { |
| // using MetadataCompleter = |
| // Metadata *(Metadata *type, |
| // MetadataCompletionContext *context, |
| // const GenericMetadataPattern *pattern); |
| llvm::Function *f = |
| IGM.getAddrOfTypeMetadataCompletionFunction(Target, ForDefinition); |
| 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 *metadata = params.claimNext(); |
| llvm::Value *context = params.claimNext(); |
| llvm::Value *templatePointer = params.claimNext(); |
| |
| (void) context; |
| (void) templatePointer; |
| |
| // Bind the generic arguments. |
| // FIXME: this will be problematic if we ever try to bind superclass |
| // types from type metadata! |
| if (Target->isGenericContext()) { |
| auto type = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| IGF.bindLocalTypeDataFromTypeMetadata(type, IsExact, metadata); |
| } |
| |
| // A dependent VWT means that we have dependent metadata. |
| if (HasDependentVWT) |
| HasDependentMetadata = true; |
| |
| if (HasDependentMetadata) { |
| asImpl().emitInitializeMetadata(IGF, metadata, false); |
| } |
| |
| // The metadata is now complete. Return null to indicate success. |
| auto nullDependency = |
| llvm::ConstantPointerNull::get(IGM.TypeMetadataPtrTy); |
| IGF.Builder.CreateRet(nullDependency); |
| } |
| |
| /// The information necessary to fill in a GenericMetadataPartialPattern |
| /// structure. |
| struct PartialPattern { |
| llvm::Constant *Data; |
| Size DataOffset; |
| Size DataSize; |
| }; |
| void addPartialPattern(PartialPattern pattern) { |
| // RelativeDirectPointer<void*> Pattern; |
| B.addRelativeAddress(pattern.Data); |
| |
| // uint16_t OffsetInWords; |
| B.addInt16(IGM.getOffsetInWords(pattern.DataOffset)); |
| |
| // uint16_t SizeInWords; |
| B.addInt16(IGM.getOffsetInWords(pattern.DataSize)); |
| } |
| |
| public: |
| void createMetadataAccessFunction() { |
| (void) getGenericTypeMetadataAccessFunction(IGM, Target, ForDefinition); |
| } |
| |
| void layout() { |
| asImpl().layoutHeader(); |
| |
| if (asImpl().hasExtraDataPattern()) { |
| asImpl().addExtraDataPattern(); |
| } |
| |
| // Immediate-members pattern. This is only valid for classes. |
| if (asImpl().hasImmediateMembersPattern()) { |
| asImpl().addImmediateMembersPattern(); |
| } |
| |
| // We're done with the pattern now. |
| #ifndef NDEBUG |
| auto finalOffset = B.getNextOffsetFromGlobal(); |
| #endif |
| |
| asImpl().emitInstantiationDefinitions(); |
| |
| assert(finalOffset == B.getNextOffsetFromGlobal() && |
| "emitInstantiationDefinitions added members to the pattern!"); |
| } |
| |
| // Emit the fields of GenericMetadataPattern. |
| void layoutHeader() { |
| // RelativePointer<MetadataInstantiator> InstantiationFunction; |
| asImpl().addInstantiationFunction(); |
| |
| // RelativePointer<MetadataCompleter> CompletionFunction; |
| asImpl().addCompletionFunction(); |
| |
| // ClassMetadataPatternFlags PatternFlags; |
| asImpl().addPatternFlags(); |
| } |
| |
| void addInstantiationFunction() { |
| auto function = IGM.getAddrOfTypeMetadataInstantiationFunction(Target, |
| NotForDefinition); |
| B.addRelativeAddress(function); |
| } |
| |
| void addCompletionFunction() { |
| if (!asImpl().hasCompletionFunction()) { |
| B.addInt32(0); |
| return; |
| } |
| |
| auto function = IGM.getAddrOfTypeMetadataCompletionFunction(Target, |
| NotForDefinition); |
| B.addRelativeAddress(function); |
| } |
| |
| void addPatternFlags() { |
| GenericMetadataPatternFlags flags = asImpl().getPatternFlags(); |
| B.addInt32(flags.getOpaqueValue()); |
| } |
| |
| GenericMetadataPatternFlags getPatternFlags() { |
| GenericMetadataPatternFlags flags; |
| |
| if (asImpl().hasExtraDataPattern()) |
| flags.setHasExtraDataPattern(true); |
| |
| return flags; |
| } |
| |
| bool hasExtraDataPattern() { |
| return false; |
| } |
| void addExtraDataPattern() { |
| asImpl().addPartialPattern(asImpl().buildExtraDataPattern()); |
| } |
| PartialPattern buildExtraDataPattern() { |
| llvm_unreachable("no extra data pattern!"); |
| } |
| |
| bool hasImmediateMembersPattern() { |
| return false; |
| } |
| void addImmediateMembersPattern() { |
| asImpl().addPartialPattern(asImpl().buildImmediateMembersPattern()); |
| } |
| PartialPattern buildImmediateMembersPattern() { |
| llvm_unreachable("no immediate members pattern!"); |
| } |
| |
| void emitInstantiationDefinitions() { |
| // Register fill ops for all the immediate type arguments. |
| // This must happen before we emit the instantiation function below. |
| asImpl().addGenericFields(Target, Target->getDeclaredTypeInContext()); |
| |
| // Force the emission of the nominal type descriptor, although we |
| // don't use it yet. |
| (void) asImpl().emitNominalTypeDescriptor(); |
| |
| // Emit the instantiation function. |
| asImpl().emitInstantiationFunction(); |
| |
| // Emit the completion function. |
| if (asImpl().hasCompletionFunction()) |
| asImpl().emitCompletionFunction(); |
| |
| // Emit the instantiation cache. |
| asImpl().emitInstantiationCache(); |
| } |
| |
| template <class... T> |
| void addGenericArgument(CanType type, T &&...args) { |
| FillOps.push_back({type, None}); |
| } |
| |
| template <class... T> |
| void addGenericWitnessTable(CanType type, ProtocolConformanceRef conf, |
| T &&...args) { |
| FillOps.push_back({type, conf}); |
| } |
| }; |
| |
| template <class Impl, class Base> |
| class GenericValueMetadataBuilderBase |
| : public GenericMetadataBuilderBase<Impl, Base> { |
| using super = GenericMetadataBuilderBase<Impl, Base>; |
| protected: |
| using super::IGM; |
| using super::asImpl; |
| using super::Target; |
| using super::B; |
| |
| template <class... T> |
| GenericValueMetadataBuilderBase(IRGenModule &IGM, T &&...args) |
| : super(IGM, std::forward<T>(args)...) {} |
| |
| public: |
| /// Emit the fields of a GenericValueMetadataPattern. |
| void layoutHeader() { |
| super::layoutHeader(); |
| |
| // RelativeIndirectablePointer<const ValueWitnessTable> ValueWitnesses; |
| asImpl().addValueWitnessTable(); |
| |
| } |
| |
| GenericMetadataPatternFlags getPatternFlags() { |
| auto flags = super::getPatternFlags(); |
| |
| flags.value_setMetadataKind(asImpl().getMetadataKind()); |
| |
| assert(!asImpl().hasImmediateMembersPattern()); |
| |
| return flags; |
| } |
| |
| void addValueWitnessTable() { |
| auto table = asImpl().emitValueWitnessTable(); |
| B.addRelativeAddress(table); |
| } |
| }; |
| } // end anonymous namespace |
| |
| void irgen::emitInitializeFieldOffsetVector(IRGenFunction &IGF, |
| SILType T, |
| llvm::Value *metadata, |
| bool isVWTMutable) { |
| 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)) { |
| IGF.Builder.CreateCall(IGF.IGM.getInitClassMetadataUniversalFn(), |
| {metadata, numFields, |
| fields.getAddress(), fieldVector}); |
| } else { |
| assert(isa<StructDecl>(target)); |
| StructLayoutFlags flags = StructLayoutFlags::Swift5Algorithm; |
| if (isVWTMutable) |
| flags |= StructLayoutFlags::IsVWTMutable; |
| |
| IGF.Builder.CreateCall(IGF.IGM.getInitStructMetadataFn(), |
| {metadata, IGF.IGM.getSize(Size(uintptr_t(flags))), |
| numFields, fields.getAddress(), fieldVector}); |
| } |
| |
| IGF.Builder.CreateLifetimeEnd(fields, |
| IGF.IGM.getPointerSize() * storedProperties.size()); |
| } |
| |
| // Classes |
| |
| namespace { |
| /// Utility class for building member metadata for classes where the |
| /// entire hierarchy is in the current resilience domain, and all stored |
| /// properties have a fixed size. |
| class FixedClassMemberBuilder { |
| IRGenModule &IGM; |
| ConstantStructBuilder &B; |
| const StructLayout &Layout; |
| const ClassLayout &FieldLayout; |
| SILVTable *VTable; |
| |
| public: |
| FixedClassMemberBuilder(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : IGM(IGM), B(builder), Layout(layout), FieldLayout(fieldLayout) { |
| VTable = IGM.getSILModule().lookUpVTable(theClass); |
| } |
| |
| void addFieldOffset(VarDecl *var) { |
| unsigned fieldIndex = FieldLayout.getFieldIndex(var); |
| auto &element = Layout.getElement(fieldIndex); |
| assert(element.getKind() == ElementLayout::Kind::Fixed || |
| element.getKind() == ElementLayout::Kind::Empty); |
| |
| B.addInt(IGM.SizeTy, element.getByteOffset().getValue()); |
| } |
| |
| 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); |
| |
| // 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 emitInitializeMethodOverrides(IRGenFunction &IGF, |
| llvm::Value *metadata) {} |
| |
| void addGenericArgument(CanType argTy, ClassDecl *forClass) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addGenericWitnessTable(CanType argTy, ProtocolConformanceRef conf, |
| ClassDecl *forClass) { |
| B.addNullPointer(IGM.WitnessTablePtrTy); |
| } |
| }; |
| |
| /// Utility class for building member metadata for classes that inherit |
| /// from a class in a different resilience domain, or have fields whose |
| /// size is not known at compile time. |
| class ResilientClassMemberBuilder { |
| IRGenModule &IGM; |
| SILVTable *VTable; |
| |
| public: |
| ResilientClassMemberBuilder(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : IGM(IGM) { |
| VTable = IGM.getSILModule().lookUpVTable(theClass); |
| } |
| |
| void addFieldOffset(VarDecl *var) {} |
| |
| void addFieldOffsetPlaceholders(MissingMemberDecl *placeholder) {} |
| |
| void addMethod(SILDeclRef fn) {} |
| |
| // 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) { |
| for (auto &entry : VTable->getEntries()) { |
| if (entry.TheKind != SILVTable::Entry::Kind::Override) |
| continue; |
| |
| auto fn = entry.Method; |
| |
| auto *classDecl = cast<ClassDecl>(fn.getDecl()->getDeclContext()); |
| auto &layout = IGM.getClassMetadataLayout(classDecl); |
| |
| auto offset = layout.getMethodInfo(IGF, fn).getOffset(); |
| |
| auto slot = IGF.emitAddressAtOffset(metadata, offset, |
| IGM.Int8PtrTy, |
| IGM.getPointerAlignment()); |
| |
| auto *implFn = IGM.getAddrOfSILFunction(entry.Implementation, |
| NotForDefinition); |
| auto *value = IGF.Builder.CreateBitCast(implFn, IGM.Int8PtrTy); |
| IGF.Builder.CreateStore(value, slot); |
| } |
| } |
| |
| void addGenericArgument(CanType argTy, ClassDecl *forClass) {} |
| |
| void addGenericWitnessTable(CanType argTy, ProtocolConformanceRef conf, |
| ClassDecl *forClass) {} |
| }; |
| |
| /// Base class for laying out class metadata. |
| template <class Impl, class MemberBuilder> |
| 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; |
| ClassMetadataLayout &MetadataLayout; |
| |
| MemberBuilder Members; |
| |
| ClassMetadataBuilderBase(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : super(IGM, theClass), B(builder), |
| Layout(layout), FieldLayout(fieldLayout), |
| MetadataLayout(IGM.getClassMetadataLayout(theClass)), |
| Members(IGM, theClass, builder, layout, fieldLayout) {} |
| |
| public: |
| void noteResilientSuperclass() {} |
| |
| void noteStartOfImmediateMembers(ClassDecl *theClass) { |
| if (theClass == Target) { |
| emitClassMetadataBaseOffset(); |
| } |
| } |
| |
| /// Emit the base-offset variable for the class. |
| void emitClassMetadataBaseOffset() { |
| // Only classes defined in resilient modules, or those that have |
| // a resilient superclass need this. |
| if (!MetadataLayout.hasResilientSuperclass() && |
| !IGM.isResilient(Target, ResilienceExpansion::Minimal)) { |
| return; |
| } |
| |
| auto *offsetAddr = |
| IGM.getAddrOfClassMetadataBounds(Target, ForDefinition); |
| auto *offsetVar = cast<llvm::GlobalVariable>(offsetAddr); |
| |
| if (MetadataLayout.hasResilientSuperclass()) { |
| // If the superclass is resilient to us, we have to compute and |
| // initialize the global when we initialize the metadata. |
| auto init = llvm::ConstantAggregateZero::get(offsetVar->getValueType()); |
| |
| offsetVar->setInitializer(init); |
| offsetVar->setConstant(false); |
| return; |
| } |
| |
| // Otherwise, we know the offset at compile time, even if our |
| // clients do not, so just emit a constant. |
| auto &layout = IGM.getClassMetadataLayout(Target); |
| |
| auto immediateMembersOffset = layout.getStartOfImmediateMembers(); |
| auto size = layout.getSize(); |
| auto negativeSizeInWords = size.AddressPoint / IGM.getPointerSize(); |
| auto positiveSizeInWords = size.getOffsetToEnd() / IGM.getPointerSize(); |
| |
| auto initTy = cast<llvm::StructType>(offsetVar->getValueType()); |
| auto *init = llvm::ConstantStruct::get(initTy, { |
| llvm::ConstantInt::get(IGM.SizeTy, immediateMembersOffset.getValue()), |
| llvm::ConstantInt::get(IGM.Int32Ty, negativeSizeInWords), |
| llvm::ConstantInt::get(IGM.Int32Ty, positiveSizeInWords) |
| }); |
| |
| offsetVar->setInitializer(init); |
| offsetVar->setConstant(true); |
| } |
| |
| /// 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() { |
| if (auto ptr = getAddrOfDestructorFunction()) { |
| B.add(*ptr); |
| } else { |
| // In case the optimizer removed the function. See comment in |
| // addMethod(). |
| B.addNullPointer(IGM.FunctionPtrTy); |
| } |
| } |
| |
| Optional<llvm::Constant *> getAddrOfDestructorFunction() { |
| auto dtorRef = SILDeclRef(Target->getDestructor(), |
| SILDeclRef::Kind::Deallocator); |
| SILFunction *dtorFunc = IGM.getSILModule().lookUpFunction(dtorRef); |
| if (!dtorFunc) return llvm::None; |
| return IGM.getAddrOfSILFunction(dtorFunc, NotForDefinition); |
| } |
| |
| void addNominalTypeDescriptor() { |
| auto descriptor = asImpl().emitNominalTypeDescriptor(); |
| B.add(descriptor); |
| } |
| |
| llvm::Constant *emitNominalTypeDescriptor() { |
| return ClassContextDescriptorBuilder(IGM, Target, RequireMetadata).emit(); |
| } |
| |
| void addIVarDestroyer() { |
| auto dtorFunc = getAddrOfIVarDestroyer(); |
| if (dtorFunc) { |
| B.add(*dtorFunc); |
| } else { |
| B.addNullPointer(IGM.FunctionPtrTy); |
| } |
| } |
| |
| Optional<llvm::Function *> getAddrOfIVarDestroyer() { |
| return IGM.getAddrOfIVarInitDestroy(Target, |
| /*isDestroyer=*/ true, |
| /*isForeign=*/ false, |
| NotForDefinition); |
| } |
| |
| 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() { |
| auto flags = ClassFlags(); |
| |
| #if !SWIFT_DARWIN_ENABLE_STABLE_ABI_BIT |
| // FIXME: Remove this after enabling stable ABI. |
| // This bit is NOT conditioned on UseDarwinPreStableABIBit. |
| flags |= ClassFlags::IsSwiftPreStableABI; |
| #endif |
| |
| // Set a flag if the class uses Swift refcounting. |
| auto type = Target->getDeclaredType()->getCanonicalType(); |
| if (getReferenceCountingForType(IGM, type) |
| == ReferenceCounting::Native) { |
| flags |= ClassFlags::UsesSwiftRefcounting; |
| } |
| |
| // Set a flag if the class has a custom ObjC name. |
| 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 = MetadataLayout.getSize(); |
| B.addInt32(size.FullSize.getValue()); |
| } |
| |
| void addClassAddressPoint() { |
| // FIXME: Wrong |
| auto size = MetadataLayout.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. |
| // FIXME: Remove null data altogether rdar://problem/18801263 |
| B.addInt(IGM.IntPtrTy, 1); |
| return; |
| } |
| |
| // Derive the RO-data. |
| llvm::Constant *data = emitClassPrivateData(IGM, Target); |
| |
| // Set a low bit to indicate this class has Swift metadata. |
| auto bit = llvm::ConstantInt::get(IGM.IntPtrTy, |
| IGM.UseDarwinPreStableABIBit ? 1 : 2); |
| |
| // Emit data + bit. |
| data = llvm::ConstantExpr::getPtrToInt(data, IGM.IntPtrTy); |
| data = llvm::ConstantExpr::getAdd(data, bit); |
| B.add(data); |
| } |
| |
| void addFieldOffset(VarDecl *var) { |
| Members.addFieldOffset(var); |
| } |
| |
| void addFieldOffsetPlaceholders(MissingMemberDecl *placeholder) { |
| Members.addFieldOffsetPlaceholders(placeholder); |
| } |
| |
| void addMethod(SILDeclRef fn) { |
| Members.addMethod(fn); |
| } |
| |
| 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) { |
| Members.addGenericArgument(argTy, forClass); |
| } |
| |
| void addGenericWitnessTable(CanType argTy, ProtocolConformanceRef conf, |
| ClassDecl *forClass) { |
| Members.addGenericWitnessTable(argTy, conf, forClass); |
| } |
| |
| protected: |
| 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) { |
| if (doesClassMetadataRequireDynamicInitialization(IGF.IGM, Target)) { |
| // We need to: |
| // - fill out the subclass's field offset vector |
| // - copy field offsets and generic arguments from higher in the |
| // class hierarchy |
| auto classTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| auto loweredClassTy = IGF.IGM.getLoweredType(classTy); |
| emitInitializeFieldOffsetVector(IGF, loweredClassTy, |
| metadata, /*VWT is mutable*/ false); |
| |
| // 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 (!IGF.IGM.ObjCInterop) |
| emitInitializeFieldOffsets(IGF, metadata); |
| } else { |
| // Otherwise, all we need to do is register with the ObjC runtime. |
| metadata = emitFinishIdempotentInitialization(IGF, metadata); |
| } |
| |
| emitFieldOffsetGlobals(); |
| |
| emitInitializeMethodOverrides(IGF, metadata); |
| |
| return metadata; |
| } |
| |
| /// Materialize type metadata for the given type and store it into the |
| /// superclass field of the given metadata. |
| void emitStoreOfSuperclass(IRGenFunction &IGF, CanType superclassType, |
| llvm::Value *metadata) { |
| llvm::Value *superMetadata = |
| emitClassHeapMetadataRef(IGF, superclassType, |
| MetadataValueType::TypeMetadata, |
| /*allowUninit*/ false); |
| |
| Address superField = |
| emitAddressOfSuperclassRefInClassMetadata(IGF, metadata); |
| superField = IGF.Builder.CreateElementBitCast(superField, |
| IGM.TypeMetadataPtrTy); |
| IGF.Builder.CreateStore(superMetadata, superField); |
| } |
| |
| // 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) { |
| Members.emitInitializeMethodOverrides(IGF, metadata); |
| } |
| |
| // 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) { |
| for (auto prop : Target->getStoredProperties()) { |
| unsigned fieldIndex = FieldLayout.getFieldIndex(prop); |
| auto access = FieldLayout.AllFieldAccesses[fieldIndex]; |
| if (access == FieldAccess::NonConstantDirect) { |
| Address offsetA = IGF.IGM.getAddrOfFieldOffset(prop, 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); |
| } |
| } |
| } |
| |
| void emitFieldOffsetGlobals() { |
| for (auto prop : Target->getStoredProperties()) { |
| unsigned fieldIndex = FieldLayout.getFieldIndex(prop); |
| 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)); |
| } |
| |
| 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(prop, 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; |
| } |
| } |
| } |
| }; |
| |
| /// Base class for layout of non-generic class metadata. |
| template<class Impl, class MemberBuilder> |
| class ConcreteClassMetadataBuilderBase : |
| public ClassMetadataBuilderBase<Impl, MemberBuilder> { |
| |
| using super = ClassMetadataBuilderBase<Impl, MemberBuilder>; |
| |
| using super::IGM; |
| using super::Target; |
| using super::B; |
| using super::addReferenceToHeapMetadata; |
| using super::emitFinishInitializationOfClassMetadata; |
| using super::emitFinishIdempotentInitialization; |
| using super::emitFieldOffsetGlobals; |
| |
| bool HasUnfilledSuperclass = false; |
| Size AddressPoint; |
| |
| public: |
| ConcreteClassMetadataBuilderBase(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : super(IGM, theClass, builder, layout, fieldLayout) { |
| } |
| |
| void noteAddressPoint() { |
| super::noteAddressPoint(); |
| AddressPoint = B.getNextOffsetFromGlobal(); |
| } |
| |
| 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; |
| } |
| } |
| |
| 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 && |
| !doesClassMetadataRequireDynamicInitialization(IGM, Target)) { |
| emitFieldOffsetGlobals(); |
| |
| auto type = Target->getDeclaredType()->getCanonicalType(); |
| auto metadata = IGF.IGM.getAddrOfTypeMetadata(type); |
| 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(); |
| this->emitStoreOfSuperclass(IGF, superclass, metadata); |
| } |
| |
| // Relocate the metadata if it has a superclass that is resilient |
| // to us. |
| if (doesClassMetadataRequireDynamicInitialization(IGM, Target)) { |
| auto templateSize = IGM.getSize(Size(B.getNextOffsetFromGlobal())); |
| auto numImmediateMembers = IGM.getSize( |
| Size(IGM.getClassMetadataLayout(Target).getNumImmediateMembers())); |
| metadata = IGF.Builder.CreateCall(IGF.IGM.getRelocateClassMetadataFn(), |
| {metadata, templateSize, |
| numImmediateMembers}); |
| } |
| |
| return emitFinishInitializationOfClassMetadata(IGF, metadata); |
| } |
| }; |
| |
| /// A builder for fixed-size, non-generic class metadata. |
| class FixedClassMetadataBuilder : |
| public ConcreteClassMetadataBuilderBase<FixedClassMetadataBuilder, |
| FixedClassMemberBuilder> { |
| using super = ConcreteClassMetadataBuilderBase<FixedClassMetadataBuilder, |
| FixedClassMemberBuilder>; |
| |
| public: |
| FixedClassMetadataBuilder(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : super(IGM, theClass, builder, layout, fieldLayout) {} |
| }; |
| |
| /// A builder for resilient, non-generic class metadata. |
| class ResilientClassMetadataBuilder : |
| public ConcreteClassMetadataBuilderBase<ResilientClassMetadataBuilder, |
| ResilientClassMemberBuilder> { |
| using super = ConcreteClassMetadataBuilderBase<ResilientClassMetadataBuilder, |
| ResilientClassMemberBuilder>; |
| |
| public: |
| ResilientClassMetadataBuilder(IRGenModule &IGM, ClassDecl *theClass, |
| ConstantStructBuilder &builder, |
| const StructLayout &layout, |
| const ClassLayout &fieldLayout) |
| : super(IGM, theClass, builder, layout, fieldLayout) {} |
| }; |
| |
| /// A builder for GenericClassMetadataPattern objects. |
| class GenericClassMetadataBuilder : |
| public GenericMetadataBuilderBase<GenericClassMetadataBuilder, |
| ClassMetadataBuilderBase<GenericClassMetadataBuilder, |
| ResilientClassMemberBuilder>> |
| { |
| typedef GenericMetadataBuilderBase super; |
| |
| Optional<ConstantAggregateBuilderBase::PlaceholderPosition> |
| ClassRODataOffset, MetaclassObjectOffset, MetaclassRODataOffset; |
| 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 layoutHeader() { |
| super::layoutHeader(); |
| |
| // RelativePointer<HeapObjectDestroyer> Destroy; |
| addDestructorFunction(); |
| |
| // RelativePointer<ClassIVarDestroyer> IVarDestroyer; |
| addIVarDestroyer(); |
| |
| // ClassFlags Flags; |
| addClassFlags(); |
| |
| // uint16_t ClassRODataOffset; |
| if (IGM.ObjCInterop) |
| ClassRODataOffset = B.addPlaceholderWithSize(IGM.Int16Ty); |
| else |
| B.addInt16(0); |
| |
| // uint16_t MetaclassObjectOffset; |
| if (IGM.ObjCInterop) |
| MetaclassObjectOffset = B.addPlaceholderWithSize(IGM.Int16Ty); |
| else |
| B.addInt16(0); |
| |
| // uint16_t MetadataRODataOffset; |
| if (IGM.ObjCInterop) |
| MetaclassRODataOffset = B.addPlaceholderWithSize(IGM.Int16Ty); |
| else |
| B.addInt16(0); |
| |
| // uint16_t Reserved; |
| B.addInt16(0); |
| } |
| |
| GenericMetadataPatternFlags getPatternFlags() { |
| auto flags = super::getPatternFlags(); |
| |
| flags.class_setHasImmediateMembersPattern(hasImmediateMembersPattern()); |
| |
| return flags; |
| } |
| |
| void emitInstantiationDefinitions() { |
| // Emit the base-offset variable. |
| emitClassMetadataBaseOffset(); |
| |
| super::emitInstantiationDefinitions(); |
| } |
| |
| void addDestructorFunction() { |
| auto function = getAddrOfDestructorFunction(); |
| B.addRelativeAddressOrNull(function ? *function : nullptr); |
| } |
| |
| void addIVarDestroyer() { |
| auto function = getAddrOfIVarDestroyer(); |
| B.addRelativeAddressOrNull(function ? *function : nullptr); |
| } |
| |
| bool hasExtraDataPattern() { |
| return IGM.ObjCInterop; |
| } |
| |
| PartialPattern buildExtraDataPattern() { |
| ConstantInitBuilder subBuilder(IGM); |
| auto subB = subBuilder.beginStruct(); |
| subB.setPacked(true); |
| |
| // The offset of the pattern bytes in the overall extra-data section. |
| // Any bytes before this will be zeroed. Currently we don't take |
| // advantage of this. |
| Size patternOffset = Size(0); |
| |
| if (IGM.ObjCInterop) { |
| // Add the metaclass object. |
| B.fillPlaceholderWithInt(*MetaclassObjectOffset, IGM.Int16Ty, |
| IGM.getOffsetInWords(patternOffset + subB.getNextOffsetFromGlobal())); |
| addMetaclassObject(subB); |
| |
| // Add the RO-data objects. |
| auto roDataPoints = |
| emitClassPrivateDataFields(IGM, subB, Target); |
| B.fillPlaceholderWithInt(*ClassRODataOffset, IGM.Int16Ty, |
| IGM.getOffsetInWords(patternOffset + roDataPoints.first)); |
| B.fillPlaceholderWithInt(*MetaclassRODataOffset, IGM.Int16Ty, |
| IGM.getOffsetInWords(patternOffset + roDataPoints.second)); |
| } |
| |
| auto patternSize = subB.getNextOffsetFromGlobal(); |
| |
| auto global = subB.finishAndCreateGlobal("", IGM.getPointerAlignment(), |
| /*constant*/ true); |
| |
| return { global, patternOffset, patternSize }; |
| } |
| |
| void addMetaclassObject(ConstantStructBuilder &B) { |
| // 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 |
| B.addInt(IGM.IntPtrTy, 0); |
| } |
| |
| bool hasImmediateMembersPattern() { |
| // TODO: use the real field offsets if they're known statically. |
| return false; |
| } |
| |
| llvm::Value *emitAllocateMetadata(IRGenFunction &IGF, |
| llvm::Value *descriptor, |
| llvm::Value *arguments, |
| llvm::Value *templatePointer) { |
| auto metadata = |
| IGF.Builder.CreateCall(IGM.getAllocateGenericClassMetadataFn(), |
| {descriptor, arguments, templatePointer}); |
| |
| return metadata; |
| } |
| |
| bool hasCompletionFunction() { |
| // TODO: recognize cases where this is not required. |
| // For example, under ObjCInterop mode we can move class realization |
| // into the allocation phase if the superclass is trivial and there's |
| // no layout to do. |
| return true; |
| } |
| |
| void emitInitializeMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| bool isVWTMutable) { |
| assert(!HasDependentVWT && "class should never have dependent VWT"); |
| |
| // Install the superclass. The runtime takes care of installing |
| // SwiftObject if we're building with ObjC interop and don't have |
| // a formal superclass. |
| if (Target->hasSuperclass()) { |
| CanType superclass = Target->mapTypeIntoContext(Target->getSuperclass()) |
| ->getCanonicalType(); |
| emitStoreOfSuperclass(IGF, superclass, metadata); |
| } |
| |
| // 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; |
| |
| builder.createMetadataAccessFunction(); |
| } else if (doesClassMetadataRequireDynamicInitialization(IGM, classDecl)) { |
| ResilientClassMetadataBuilder builder(IGM, classDecl, init, |
| layout, fieldLayout); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| builder.createMetadataAccessFunction(); |
| } else { |
| FixedClassMetadataBuilder builder(IGM, classDecl, init, |
| layout, fieldLayout); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| builder.createMetadataAccessFunction(); |
| } |
| |
| 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.getClassMetadataLayout(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; |
| } |
| |
| FunctionPointer irgen::emitVirtualMethodValue(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| SILDeclRef method, |
| CanSILFunctionType methodType) { |
| Signature signature = IGF.IGM.getSignature(methodType); |
| |
| auto classDecl = cast<ClassDecl>(method.getDecl()->getDeclContext()); |
| |
| // Find the vtable entry we're interested in. |
| auto methodInfo = |
| IGF.IGM.getClassMetadataLayout(classDecl).getMethodInfo(IGF, method); |
| auto offset = methodInfo.getOffset(); |
| |
| auto slot = IGF.emitAddressAtOffset(metadata, offset, |
| signature.getType()->getPointerTo(), |
| IGF.IGM.getPointerAlignment()); |
| auto fnPtr = IGF.emitInvariantLoad(slot); |
| |
| return FunctionPointer(fnPtr, signature); |
| } |
| |
| 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 = method.getOverriddenVTableEntry(); |
| |
| // 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); |
| } |
| } |
| |
| return emitVirtualMethodValue(IGF, metadata, overridden, methodType); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Value types (structs and enums) |
| //===----------------------------------------------------------------------===// |
| |
| static llvm::Value * |
| emitInPlaceValueTypeMetadataInitialization(IRGenFunction &IGF, |
| CanNominalType type, |
| llvm::Value *metadata) { |
| // All the value types are basically similar, as are foreign types. |
| assert(isa<StructType>(type) || isa<EnumType>(type) || |
| IGF.IGM.requiresForeignTypeMetadata(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()) { |
| // Initialize the metadata. |
| ti.initializeMetadata(IGF, metadata, true, 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 noteStartOfTypeSpecificMembers() {} |
| |
| SILType getLoweredType() { |
| return IGM.getLoweredType(Target->getDeclaredTypeInContext()); |
| } |
| |
| MetadataKind getMetadataKind() { |
| return MetadataKind::Struct; |
| } |
| |
| void addMetadataFlags() { |
| B.addInt(IGM.MetadataKindTy, unsigned(getMetadataKind())); |
| } |
| |
| llvm::Constant *emitNominalTypeDescriptor() { |
| auto descriptor = |
| StructContextDescriptorBuilder(IGM, Target, RequireMetadata).emit(); |
| return descriptor; |
| } |
| |
| void addNominalTypeDescriptor() { |
| B.add(emitNominalTypeDescriptor()); |
| } |
| |
| llvm::Constant *emitValueWitnessTable() { |
| auto type = this->Target->getDeclaredType()->getCanonicalType(); |
| return irgen::emitValueWitnessTable(IGM, type, false); |
| } |
| |
| void addValueWitnessTable() { |
| B.add(emitValueWitnessTable()); |
| } |
| |
| void addFieldOffset(VarDecl *var) { |
| assert(var->hasStorage() && |
| "storing field offset for computed property?!"); |
| SILType structType = getLoweredType(); |
| |
| 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 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); |
| return emitValueWitnessTable(IGM, unboundType, dependent); |
| } |
| |
| /// A builder for metadata templates. |
| class GenericStructMetadataBuilder : |
| public GenericValueMetadataBuilderBase<GenericStructMetadataBuilder, |
| StructMetadataBuilderBase<GenericStructMetadataBuilder>> { |
| |
| typedef GenericValueMetadataBuilderBase super; |
| |
| public: |
| GenericStructMetadataBuilder(IRGenModule &IGM, StructDecl *theStruct, |
| ConstantStructBuilder &B) |
| : super(IGM, theStruct, B) {} |
| |
| llvm::Value *emitAllocateMetadata(IRGenFunction &IGF, |
| llvm::Value *descriptor, |
| llvm::Value *arguments, |
| llvm::Value *templatePointer) { |
| auto &layout = IGM.getMetadataLayout(Target); |
| auto extraSize = layout.getSize().getOffsetToEnd() |
| - IGM.getOffsetOfStructTypeSpecificMetadataMembers(); |
| auto extraSizeV = IGM.getSize(extraSize); |
| |
| return IGF.Builder.CreateCall(IGM.getAllocateGenericValueMetadataFn(), |
| {descriptor, arguments, templatePointer, |
| extraSizeV}); |
| } |
| |
| void flagUnfilledFieldOffset() { |
| // We just assume this might happen. |
| } |
| |
| llvm::Constant *emitValueWitnessTable() { |
| return getValueWitnessTableForGenericValueType(IGM, Target, |
| HasDependentVWT); |
| } |
| |
| bool hasExtraDataPattern() { |
| auto &ti = IGM.getTypeInfo(getLoweredType()); |
| if (!isa<FixedTypeInfo>(ti)) |
| return false; |
| |
| if (Target->getStoredProperties().empty()) |
| return false; |
| |
| return true; |
| } |
| |
| /// Fill in a constant field offset vector if possible. |
| PartialPattern buildExtraDataPattern() { |
| ConstantInitBuilder builder(IGM); |
| auto init = builder.beginArray(IGM.SizeTy); |
| |
| struct Scanner : StructMetadataScanner<Scanner> { |
| SILType Type; |
| ConstantArrayBuilder &B; |
| Scanner(IRGenModule &IGM, StructDecl *target, SILType type, |
| ConstantArrayBuilder &B) |
| : StructMetadataScanner(IGM, target), Type(type), B(B) {} |
| |
| void addFieldOffset(VarDecl *field) { |
| auto offset = emitPhysicalStructMemberFixedOffset(IGM, Type, field); |
| if (offset) { |
| B.add(offset); |
| return; |
| } |
| assert(IGM.isKnownEmpty(Type.getFieldType(field, IGM.getSILModule()), |
| ResilienceExpansion::Maximal)); |
| B.addInt(IGM.SizeTy, 0); |
| } |
| }; |
| Scanner(IGM, Target, getLoweredType(), init).layout(); |
| Size vectorSize = init.getNextOffsetFromGlobal(); |
| |
| auto global = init.finishAndCreateGlobal("", IGM.getPointerAlignment(), |
| /*constant*/ true); |
| |
| auto &layout = IGM.getMetadataLayout(Target); |
| return { global, |
| layout.getFieldOffsetVectorOffset().getStatic() |
| - IGM.getOffsetOfStructTypeSpecificMetadataMembers(), |
| vectorSize }; |
| } |
| |
| bool hasCompletionFunction() { |
| return !isa<FixedTypeInfo>(IGM.getTypeInfo(getLoweredType())); |
| } |
| |
| void emitInitializeMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| bool isVWTMutable) { |
| // Nominal types are always preserved through SIL lowering. |
| auto loweredTy = getLoweredType(); |
| IGM.getTypeInfo(loweredTy) |
| .initializeMetadata(IGF, metadata, isVWTMutable, loweredTy); |
| } |
| }; |
| } // 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; |
| |
| builder.createMetadataAccessFunction(); |
| } else { |
| StructMetadataBuilder builder(IGM, structDecl, init); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| builder.createMetadataAccessFunction(); |
| } |
| |
| 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; |
| |
| EnumMetadataBuilderBase(IRGenModule &IGM, EnumDecl *theEnum, |
| ConstantStructBuilder &B) |
| : super(IGM, theEnum), B(B) { |
| } |
| |
| SILType getLoweredType() { |
| return IGM.getLoweredType(Target->getDeclaredTypeInContext()); |
| } |
| |
| public: |
| void noteStartOfTypeSpecificMembers() {} |
| |
| MetadataKind getMetadataKind() { |
| return Target->isOptionalDecl() ? MetadataKind::Optional |
| : MetadataKind::Enum; |
| } |
| |
| void addMetadataFlags() { |
| auto kind = getMetadataKind(); |
| B.addInt(IGM.MetadataKindTy, unsigned(kind)); |
| } |
| |
| llvm::Constant *emitValueWitnessTable() { |
| auto type = Target->getDeclaredType()->getCanonicalType(); |
| return irgen::emitValueWitnessTable(IGM, type, false); |
| } |
| |
| void addValueWitnessTable() { |
| B.add(emitValueWitnessTable()); |
| } |
| |
| llvm::Constant *emitNominalTypeDescriptor() { |
| auto descriptor = |
| EnumContextDescriptorBuilder(IGM, Target, RequireMetadata).emit(); |
| return descriptor; |
| } |
| |
| void addNominalTypeDescriptor() { |
| B.add(emitNominalTypeDescriptor()); |
| } |
| |
| void addGenericArgument(CanType type) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| } |
| |
| void addGenericWitnessTable(CanType type, ProtocolConformanceRef conf) { |
| B.addNullPointer(IGM.WitnessTablePtrTy); |
| } |
| |
| Optional<Size> getConstantPayloadSize() { |
| auto enumTy = Target->getDeclaredTypeInContext()->getCanonicalType(); |
| auto &enumTI = IGM.getTypeInfoForUnlowered(enumTy); |
| if (!enumTI.isFixedSize(ResilienceExpansion::Maximal)) { |
| return None; |
| } |
| |
| assert(!enumTI.isFixedSize(ResilienceExpansion::Minimal) && |
| "non-generic, non-resilient enums don't need payload size in metadata"); |
| auto &strategy = getEnumImplStrategy(IGM, enumTy); |
| return Size(strategy.getPayloadSizeForMetadata()); |
| } |
| }; |
| |
| class EnumMetadataBuilder |
| : public EnumMetadataBuilderBase<EnumMetadataBuilder> { |
| bool HasUnfilledPayloadSize = false; |
| |
| public: |
| EnumMetadataBuilder(IRGenModule &IGM, EnumDecl *theEnum, |
| ConstantStructBuilder &B) |
| : EnumMetadataBuilderBase(IGM, theEnum, B) {} |
| |
| |
| |
| void addPayloadSize() { |
| auto payloadSize = getConstantPayloadSize(); |
| if (!payloadSize) { |
| B.addInt(IGM.IntPtrTy, 0); |
| HasUnfilledPayloadSize = true; |
| return; |
| } |
| |
| B.addInt(IGM.IntPtrTy, payloadSize->getValue()); |
| } |
| |
| bool canBeConstant() { |
| return !HasUnfilledPayloadSize; |
| } |
| |
| void createMetadataAccessFunction() { |
| createInPlaceValueTypeMetadataAccessFunction(IGM, Target); |
| } |
| }; |
| |
| class GenericEnumMetadataBuilder |
| : public GenericValueMetadataBuilderBase<GenericEnumMetadataBuilder, |
| EnumMetadataBuilderBase<GenericEnumMetadataBuilder>> |
| { |
| public: |
| using super = GenericValueMetadataBuilderBase; |
| |
| GenericEnumMetadataBuilder(IRGenModule &IGM, EnumDecl *theEnum, |
| ConstantStructBuilder &B) |
| : super(IGM, theEnum, B) {} |
| |
| llvm::Value *emitAllocateMetadata(IRGenFunction &IGF, |
| llvm::Value *descriptor, |
| llvm::Value *arguments, |
| llvm::Value *templatePointer) { |
| auto &layout = IGM.getMetadataLayout(Target); |
| auto extraSize = layout.getSize().getOffsetToEnd() |
| - IGM.getOffsetOfEnumTypeSpecificMetadataMembers(); |
| auto extraSizeV = IGM.getSize(extraSize); |
| |
| auto metadata = |
| IGF.Builder.CreateCall(IGM.getAllocateGenericValueMetadataFn(), |
| {descriptor, arguments, templatePointer, |
| extraSizeV}); |
| |
| // Initialize the payload-size field if we have a constant value for it. |
| // This is so small that we just do it inline instead of bothering |
| // with a pattern. |
| if (layout.hasPayloadSizeOffset()) { |
| if (auto size = getConstantPayloadSize()) { |
| auto offset = layout.getPayloadSizeOffset(); |
| auto slot = IGF.emitAddressAtOffset(metadata, offset, IGM.SizeTy, |
| IGM.getPointerAlignment()); |
| IGF.Builder.CreateStore(IGM.getSize(*size), slot); |
| } |
| } |
| |
| return metadata; |
| } |
| |
| llvm::Constant *emitValueWitnessTable() { |
| return getValueWitnessTableForGenericValueType(IGM, Target, |
| HasDependentVWT); |
| } |
| |
| bool hasCompletionFunction() { |
| return !isa<FixedTypeInfo>(IGM.getTypeInfo(getLoweredType())); |
| } |
| |
| void emitInitializeMetadata(IRGenFunction &IGF, |
| llvm::Value *metadata, |
| bool isVWTMutable) { |
| // Nominal types are always preserved through SIL lowering. |
| auto enumTy = getLoweredType(); |
| IGM.getTypeInfo(enumTy) |
| .initializeMetadata(IGF, metadata, isVWTMutable, 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; |
| |
| builder.createMetadataAccessFunction(); |
| } else { |
| EnumMetadataBuilder builder(IGM, theEnum, init); |
| builder.layout(); |
| isPattern = false; |
| canBeConstant = builder.canBeConstant(); |
| |
| builder.createMetadataAccessFunction(); |
| } |
| |
| 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 { |
| /// An adapter that turns a metadata layout class into a foreign metadata |
| /// layout class. |
| /// |
| /// Foreign metadata is generated for declarations that are |
| /// synthesized by the Clang importer from C declarations, meaning they don't |
| /// have a single Swift binary that is responsible for their emission. |
| /// In this case, we emit the record into every binary that needs it, with |
| /// a header with a unique identifier string that the runtime can use to pick |
| /// the first-used instance as the canonical instance for a process. |
| 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().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(); |
| IRGenMangler mangler; |
| std::string Name = |
| mangler.mangleTypeForForeignMetadataUniquing(targetType); |
| llvm::Constant *nameStr = IGM.getAddrOfGlobalString(Name, |
| /*relatively addressed*/ true); |
| B.addRelativeAddress(nameStr); |
| } |
| |
| 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.addRelativeAddress(fn); |
| |
| // Keep pointer alignment on 64-bit platforms for further fields. |
| switch (IGM.getPointerSize().getValue()) { |
| case 4: |
| break; |
| case 8: |
| B.addInt32(0); |
| break; |
| default: |
| llvm_unreachable("unsupported word size"); |
| } |
| } |
| |
| void noteAddressPoint() { |
| AddressPoint = B.getNextOffsetFromGlobal(); |
| } |
| |
| Size getOffsetOfAddressPoint() const { return AddressPoint; } |
| |
| void createMetadataAccessFunction() { |
| auto type = cast<NominalType>(asImpl().getTargetType()); |
| |
| (void) getTypeMetadataAccessFunction(IGM, type, ForDefinition, |
| [&](IRGenFunction &IGF, |
| llvm::Constant *cacheVariable) { |
| return emitInPlaceTypeMetadataAccessFunctionBody(IGF, type, |
| cacheVariable, |
| [&](IRGenFunction &IGF, llvm::Value *candidate) { |
| auto metadata = uniqueForeignTypeMetadataRef(IGF, candidate); |
| return emitInPlaceValueTypeMetadataInitialization(IGF, type, |
| metadata); |
| }); |
| }); |
| } |
| }; |
| |
| 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) { |
| // Dig out the address of the superclass field. |
| auto &layout = IGF.IGM.getForeignMetadataLayout(Target); |
| Address metadataWords(IGF.Builder.CreateBitCast(metadata, |
| IGM.Int8PtrPtrTy), |
| IGM.getPointerAlignment()); |
| auto superclassField = |
| createPointerSizedGEP(IGF, metadataWords, |
| layout.getSuperClassOffset().getStaticOffset()); |
| superclassField = |
| IGF.Builder.CreateBitCast( |
| superclassField, |
| llvm::PointerType::get(IGM.TypeMetadataPtrTy, 0)); |
| |
| // Unique the superclass field and write it back. |
| auto superclass = IGF.Builder.CreateLoad(superclassField); |
| auto uniquedSuperclass = uniqueForeignTypeMetadataRef(IGF, superclass); |
| IGF.Builder.CreateStore(uniquedSuperclass, superclassField); |
| } |
| |
| // 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 addNominalTypeDescriptor() { |
| auto descriptor = |
| ClassContextDescriptorBuilder(this->IGM, Target, RequireMetadata).emit(); |
| B.add(descriptor); |
| } |
| |
| void noteStartOfSuperClass() { } |
| |
| void addSuperClass() { |
| auto superclassDecl = Target->getSuperclassDecl(); |
| if (!superclassDecl || !superclassDecl->isForeign()) { |
| B.addNullPointer(IGM.TypeMetadataPtrTy); |
| return; |
| } |
| |
| auto superclassType = |
| superclassDecl->swift::TypeDecl::getDeclaredInterfaceType() |
| ->getCanonicalType(); |
| auto superclass = |
| IGM.getAddrOfForeignTypeMetadataCandidate(superclassType); |
| B.add(superclass); |
| } |
| |
| 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() { |
| B.add(emitValueWitnessTable()); |
| } |
| |
| 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() { |
| B.add(emitValueWitnessTable()); |
| } |
| |
| void addPayloadSize() const { |
| llvm_unreachable("nongeneric enums shouldn't need payload size in metadata"); |
| } |
| }; |
| } // end anonymous namespace |
| |
| bool IRGenModule::requiresForeignTypeMetadata(CanType type) { |
| if (NominalTypeDecl *nominal = type->getAnyNominal()) { |
| if (auto *clas = dyn_cast<ClassDecl>(nominal)) { |
| return clas->isForeign(); |
| } |
| |
| return isa<ClangModuleUnit>(nominal->getModuleScopeContext()); |
| } |
| |
| return false; |
| } |
| |
| 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); |
| |
| // Local function to create the global variable for the foreign type |
| // metadata candidate. |
| Size addressPoint; |
| llvm::Constant *result = nullptr; |
| auto createCandidateVariable = [&] { |
| 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. |
| result = llvm::ConstantExpr::getBitCast(var, Int8PtrTy); |
| result = llvm::ConstantExpr::getInBoundsGetElementPtr( |
| Int8Ty, result, getSize(addressPoint)); |
| result = llvm::ConstantExpr::getBitCast(result, TypeMetadataPtrTy); |
| |
| // Only remember the offset. |
| GlobalVars[entity] = result; |
| }; |
| |
| // Compute the constant initializer and the offset of the type |
| // metadata candidate within it. |
| 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(); |
| |
| createCandidateVariable(); |
| builder.createMetadataAccessFunction(); |
| } else if (auto structType = dyn_cast<StructType>(type)) { |
| auto structDecl = structType->getDecl(); |
| assert(isa<ClangModuleUnit>(structDecl->getModuleScopeContext())); |
| |
| ImportedStructs.insert(structDecl); |
| |
| ForeignStructMetadataBuilder builder(*this, structDecl, init); |
| builder.layout(); |
| addressPoint = builder.getOffsetOfAddressPoint(); |
| |
| createCandidateVariable(); |
| builder.createMetadataAccessFunction(); |
| } 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(); |
| |
| createCandidateVariable(); |
| builder.createMetadataAccessFunction(); |
| } else { |
| llvm_unreachable("foreign metadata for unexpected type?!"); |
| } |
| |
| // Keep type metadata around for all types. |
| addRuntimeResolvableType(type->getAnyNominal()); |
| |
| // If the enclosing type is also an imported type, force its metadata too. |
| if (auto enclosing = type->getNominalParent()) { |
| auto canonicalEnclosing = enclosing->getCanonicalType(); |
| if (requiresForeignTypeMetadata(canonicalEnclosing)) { |
| getAddrOfForeignTypeMetadataCandidate(canonicalEnclosing); |
| } |
| } |
| |
| 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::CaseIterable: |
| 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; |
| std::string AssociatedTypeNames; |
| 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(); |
| addSuperclass(); |
| addAssociatedTypeNames(); |
| |
| 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 |
| |
| // Add the associated type name to the list. |
| if (entry.isAssociatedType()) { |
| if (!AssociatedTypeNames.empty()) |
| AssociatedTypeNames += ' '; |
| AssociatedTypeNames += entry.getAssociatedType()->getName().str(); |
| } |
| |
| 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; |
| } |
| |
| void addSuperclass() { |
| // FIXME: Implement. |
| B.addRelativeAddressOrNull(nullptr); |
| } |
| |
| void addAssociatedTypeNames() { |
| llvm::Constant *global = nullptr; |
| if (!AssociatedTypeNames.empty()) { |
| global = IGM.getAddrOfGlobalString(AssociatedTypeNames, |
| /*willBeRelativelyAddressed=*/true); |
| } |
| B.addRelativeAddressOrNull(global); |
| } |
| }; |
| } // 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->isResilient()) |
| 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); |
| |
| // Note that we emitted this protocol. |
| SwiftProtocols.push_back(protocol); |
| |
| // If the protocol is resilient, emit dispatch thunks. |
| if (isResilient(protocol, ResilienceExpansion::Minimal)) { |
| for (auto *member : protocol->getMembers()) { |
| if (auto *funcDecl = dyn_cast<FuncDecl>(member)) { |
| emitDispatchThunk(SILDeclRef(funcDecl)); |
| } |
| if (auto *ctorDecl = dyn_cast<ConstructorDecl>(member)) { |
| emitDispatchThunk(SILDeclRef(ctorDecl, SILDeclRef::Kind::Allocator)); |
| } |
| } |
| } |
| } |
| |
| /// \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; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Generic requirements. |
| //===----------------------------------------------------------------------===// |
| |
| /// Add a generic parameter reference to the given constant struct builder. |
| static void addGenericParamRef(IRGenModule &IGM, ConstantStructBuilder &B, |
| GenericSignature *sig, CanType type) { |
| // type should be either a generic parameter or dependent member type |
| // thereof. |
| |
| if (auto genericParam = dyn_cast<GenericTypeParamType>(type)) { |
| // We can encode the ordinal of a direct type parameter reference |
| // inline. |
| auto ordinal = sig->getGenericParamOrdinal(genericParam); |
| B.addInt32(ordinal << 1); |
| return; |
| } |
| |
| if (auto dmt = dyn_cast<DependentMemberType>(type)) { |
| // We have to encode the associated type path out-of-line. |
| auto assocTypeRecord = IGM.getAddrOfAssociatedTypeGenericParamRef(sig, dmt); |
| |
| B.addTaggedRelativeOffset(IGM.Int32Ty, assocTypeRecord, 1); |
| return; |
| } |
| |
| llvm_unreachable("not a generic parameter"); |
| } |
| |
| /// Add a generic requirement to the given constant struct builder. |
| static void addGenericRequirement(IRGenModule &IGM, ConstantStructBuilder &B, |
| GenericRequirementsMetadata &metadata, |
| GenericSignature *sig, |
| GenericRequirementFlags flags, |
| Type paramType, |
| llvm::function_ref<void ()> addReference) { |
| if (flags.hasKeyArgument()) |
| ++metadata.NumGenericKeyArguments; |
| if (flags.hasExtraArgument()) |
| ++metadata.NumGenericExtraArguments; |
| |
| B.addInt(IGM.Int32Ty, flags.getIntValue()); |
| addGenericParamRef(IGM, B, sig, paramType->getCanonicalType()); |
| addReference(); |
| } |
| |
| GenericRequirementsMetadata irgen::addGenericRequirements( |
| IRGenModule &IGM, ConstantStructBuilder &B, |
| GenericSignature *sig, |
| ArrayRef<Requirement> requirements) { |
| assert(sig); |
| GenericRequirementsMetadata metadata; |
| for (auto &requirement : requirements) { |
| ++metadata.NumRequirements; |
| |
| switch (auto kind = requirement.getKind()) { |
| case RequirementKind::Layout: |
| switch (auto layoutKind = |
| requirement.getLayoutConstraint()->getKind()) { |
| case LayoutConstraintKind::Class: { |
| // Encode the class constraint. |
| auto flags = GenericRequirementFlags(GenericRequirementKind::Layout, |
| /*key argument*/ false, |
| /*extra argument*/ false); |
| addGenericRequirement(IGM, B, metadata, sig, flags, |
| requirement.getFirstType(), |
| [&]{ B.addInt32((uint32_t)GenericRequirementLayoutKind::Class); }); |
| break; |
| } |
| default: |
| // No other layout constraints are supported in source-level Swift |
| // today. |
| llvm_unreachable("shouldn't show up in ABI"); |
| } |
| break; |
| |
| case RequirementKind::Conformance: { |
| // ABI TODO: We also need a *key* argument that uniquely identifies |
| // the conformance for conformance requirements as well. |
| auto protocol = requirement.getSecondType()->castTo<ProtocolType>() |
| ->getDecl(); |
| bool needsWitnessTable = |
| Lowering::TypeConverter::protocolRequiresWitnessTable(protocol); |
| auto flags = GenericRequirementFlags(GenericRequirementKind::Protocol, |
| /*TODO key argument*/ false, |
| needsWitnessTable); |
| auto descriptorRef = |
| IGM.getConstantReferenceForProtocolDescriptor(protocol); |
| addGenericRequirement(IGM, B, metadata, sig, flags, |
| requirement.getFirstType(), |
| [&]{ B.addRelativeAddress(descriptorRef); }); |
| break; |
| } |
| |
| case RequirementKind::SameType: |
| case RequirementKind::Superclass: { |
| auto abiKind = kind == RequirementKind::SameType |
| ? GenericRequirementKind::SameType |
| : GenericRequirementKind::BaseClass; |
| |
| auto flags = GenericRequirementFlags(abiKind, false, false); |
| auto typeName = |
| getTypeRef(IGM, requirement.getSecondType()->getCanonicalType()); |
| |
| addGenericRequirement(IGM, B, metadata, sig, flags, |
| requirement.getFirstType(), |
| [&]{ B.addRelativeAddress(typeName); }); |
| |
| // ABI TODO: Same type and superclass constraints also imply |
| // "same conformance" constraints on any protocol requirements of |
| // the constrained type, which we should emit. |
| break; |
| } |
| } |
| } |
| |
| return metadata; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // 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); |
| } |