} // GetHashCode

        internal override void Save(NativeWriter writer)
        {
            Debug.Assert(ElementType == null ||
                ElementType.HandleType == HandleType.TypeDefinition ||
                ElementType.HandleType == HandleType.TypeReference ||
                ElementType.HandleType == HandleType.TypeSpecification);
            writer.Write(ElementType);
            writer.Write(Rank);
            writer.Write(Sizes);
            writer.Write(LowerBounds);
        } // Save

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
        {
            // This node does not trigger generation of other nodes.
            if (relocsOnly)
                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolNode[] { this });

            var writer = new NativeWriter();
            var typeMapHashTable = new VertexHashtable();

            Section hashTableSection = writer.NewSection();
            hashTableSection.Place(typeMapHashTable);

            foreach (var mappingEntry in factory.MetadataManager.GetTypeDefinitionMapping())
            {
                if (!factory.CompilationModuleGroup.ContainsType(mappingEntry.Entity))
                    continue;

                // We are looking for any EEType - constructed or not, it has to be in the mapping
                // table so that we can map it to metadata.
                EETypeNode node = null;
                
                if (!mappingEntry.Entity.IsGenericDefinition)
                {
                    node = factory.ConstructedTypeSymbol(mappingEntry.Entity) as EETypeNode;
                }
                
                if (node == null || !node.Marked)
                {
                    // This might have been a typeof() expression.
                    node = factory.NecessaryTypeSymbol(mappingEntry.Entity) as EETypeNode;
                }

                if (node.Marked)
                {
                    Vertex vertex = writer.GetTuple(
                        writer.GetUnsignedConstant(_externalReferences.GetIndex(node)),
                        writer.GetUnsignedConstant((uint)mappingEntry.MetadataHandle)
                        );

                    int hashCode = node.Type.GetHashCode();
                    typeMapHashTable.Append((uint)hashCode, hashTableSection.Place(vertex));
                }
            }

            MemoryStream ms = new MemoryStream();
            writer.Save(ms);
            byte[] hashTableBytes = ms.ToArray();

            _endSymbol.SetSymbolOffset(hashTableBytes.Length);

            return new ObjectData(hashTableBytes, Array.Empty<Relocation>(), 1, new ISymbolNode[] { this, _endSymbol });
        }

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
        {
            // This node does not trigger generation of other nodes.
            if (relocsOnly)
                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolNode[] { this });

            var writer = new NativeWriter();
            var typeMapHashTable = new VertexHashtable();

            Section hashTableSection = writer.NewSection();
            hashTableSection.Place(typeMapHashTable);

            foreach (var node in factory.MetadataManager.GetCctorContextMapping())
            {
                MetadataType type = node.Type;

                Debug.Assert(factory.TypeSystemContext.HasLazyStaticConstructor(type));

                // If this type doesn't generate an EEType in the current compilation, don't report it in the table.
                // If nobody can get to the EEType, they can't ask to run the cctor. We don't need to force generate it.
                if (!factory.MetadataManager.TypeGeneratesEEType(type))
                    continue;

                // Hash table is hashed by the hashcode of the owning type.
                // Each entry has: the EEType of the type, followed by the non-GC static base.
                // The non-GC static base is prefixed by the class constructor context.

                // Unfortunately we need to adjust for the cctor context just so that we can subtract it again at runtime...
                int delta = NonGCStaticsNode.GetClassConstructorContextStorageSize(factory.TypeSystemContext.Target, type);

                Vertex vertex = writer.GetTuple(
                    writer.GetUnsignedConstant(_externalReferences.GetIndex(factory.NecessaryTypeSymbol(type))),
                    writer.GetUnsignedConstant(_externalReferences.GetIndex(node, delta))
                    );

                int hashCode = type.GetHashCode();
                typeMapHashTable.Append((uint)hashCode, hashTableSection.Place(vertex));
            }

            MemoryStream ms = new MemoryStream();
            writer.Save(ms);
            byte[] hashTableBytes = ms.ToArray();

            _endSymbol.SetSymbolOffset(hashTableBytes.Length);

            return new ObjectData(hashTableBytes, Array.Empty<Relocation>(), 1, new ISymbolNode[] { this, _endSymbol });
        }

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
        {
            // This node does not trigger generation of other nodes.
            if (relocsOnly)
                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolNode[] { this });

            var writer = new NativeWriter();
            var typeMapHashTable = new VertexHashtable();

            Section hashTableSection = writer.NewSection();
            hashTableSection.Place(typeMapHashTable);

            foreach (var mappingEntry in factory.MetadataManager.GetTypeDefinitionMapping())
            {
                if (!factory.CompilationModuleGroup.ContainsType(mappingEntry.Entity))
                    continue;

                // Types that don't have EETypes don't need mapping table entries because there's no risk of them
                // not unifying to the same System.Type at runtime.
                if (!factory.MetadataManager.TypeGeneratesEEType(mappingEntry.Entity))
                    continue;
                
                // Go with a necessary type symbol. It will be upgraded to a constructed one if a constructed was emitted.
                IEETypeNode typeSymbol = factory.NecessaryTypeSymbol(mappingEntry.Entity);

                Vertex vertex = writer.GetTuple(
                    writer.GetUnsignedConstant(_externalReferences.GetIndex(typeSymbol)),
                    writer.GetUnsignedConstant((uint)mappingEntry.MetadataHandle)
                    );

                int hashCode = typeSymbol.Type.GetHashCode();
                typeMapHashTable.Append((uint)hashCode, hashTableSection.Place(vertex));
            }

            MemoryStream ms = new MemoryStream();
            writer.Save(ms);
            byte[] hashTableBytes = ms.ToArray();

            _endSymbol.SetSymbolOffset(hashTableBytes.Length);

            return new ObjectData(hashTableBytes, Array.Empty<Relocation>(), 1, new ISymbolNode[] { this, _endSymbol });
        }

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
        {
            // This node does not trigger generation of other nodes.
            if (relocsOnly)
                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolNode[] { this });

            var writer = new NativeWriter();
            var typeMapHashTable = new VertexHashtable();

            Section hashTableSection = writer.NewSection();
            hashTableSection.Place(typeMapHashTable);

            foreach (var arrayType in factory.MetadataManager.GetArrayTypeMapping())
            {
                if (!arrayType.IsSzArray)
                    continue;

                if (!factory.MetadataManager.TypeGeneratesEEType(arrayType))
                    continue;

                // TODO: This should only be emitted for arrays of value types. The type loader builds everything else.

                // Go with a necessary type symbol. It will be upgraded to a constructed one if a constructed was emitted.
                IEETypeNode arrayTypeSymbol = factory.NecessaryTypeSymbol(arrayType);

                Vertex vertex = writer.GetUnsignedConstant(_externalReferences.GetIndex(arrayTypeSymbol));

                int hashCode = arrayType.GetHashCode();
                typeMapHashTable.Append((uint)hashCode, hashTableSection.Place(vertex));
            }

            MemoryStream ms = new MemoryStream();
            writer.Save(ms);
            byte[] hashTableBytes = ms.ToArray();

            _endSymbol.SetSymbolOffset(hashTableBytes.Length);

            return new ObjectData(hashTableBytes, Array.Empty<Relocation>(), 1, new ISymbolNode[] { this, _endSymbol });
        }

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
        {
            // This node does not trigger generation of other nodes.
            if (relocsOnly)
                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolNode[] { this });

            var writer = new NativeWriter();
            var typeMapHashTable = new VertexHashtable();

            Section hashTableSection = writer.NewSection();
            hashTableSection.Place(typeMapHashTable);

            // Get a list of all methods that have a method body and metadata from the metadata manager.
            foreach (var mappingEntry in factory.MetadataManager.GetMethodMapping())
            {
                MethodDesc method = mappingEntry.Entity;

                // The current format requires us to have an EEType for the owning type. We might want to lift this.
                if (!factory.MetadataManager.TypeGeneratesEEType(method.OwningType))
                    continue;

                // We have a method body, we have a metadata token, but we can't get an invoke stub. Bail.
                if (!factory.MetadataManager.HasReflectionInvokeStub(method))
                    continue;

                InvokeTableFlags flags = 0;

                if (method.HasInstantiation)
                    flags |= InvokeTableFlags.IsGenericMethod;

                if (method.GetCanonMethodTarget(CanonicalFormKind.Specific).RequiresInstArg())
                    flags |= InvokeTableFlags.RequiresInstArg;

                // TODO: better check for default public(!) constructor
                if (method.IsConstructor && method.Signature.Length == 0)
                    flags |= InvokeTableFlags.IsDefaultConstructor;

                // TODO: HasVirtualInvoke

                if (!method.IsAbstract)
                    flags |= InvokeTableFlags.HasEntrypoint;

                // Once we have a true multi module compilation story, we'll need to start emitting entries where this is not set.
                flags |= InvokeTableFlags.HasMetadataHandle;

                // TODO: native signature for P/Invokes and NativeCallable methods
                if (method.IsRawPInvoke() || method.IsNativeCallable)
                    continue;

                // Grammar of an entry in the hash table:
                // Flags + DeclaringType + MetadataHandle/NameAndSig + Entrypoint + DynamicInvokeMethod + [NumGenericArgs + GenericArgs]

                Vertex vertex = writer.GetUnsignedConstant((uint)flags);

                if ((flags & InvokeTableFlags.HasMetadataHandle) != 0)
                {
                    // Only store the offset portion of the metadata handle to get better integer compression
                    vertex = writer.GetTuple(vertex,
                        writer.GetUnsignedConstant((uint)(mappingEntry.MetadataHandle & MetadataGeneration.MetadataOffsetMask)));
                }
                else
                {
                    // TODO: no MD handle case
                }

                // Go with a necessary type symbol. It will be upgraded to a constructed one if a constructed was emitted.
                IEETypeNode owningTypeSymbol = factory.NecessaryTypeSymbol(method.OwningType);
                vertex = writer.GetTuple(vertex,
                    writer.GetUnsignedConstant(_externalReferences.GetIndex(owningTypeSymbol)));

                if ((flags & InvokeTableFlags.HasEntrypoint) != 0)
                {
                    vertex = writer.GetTuple(vertex,
                        writer.GetUnsignedConstant(_externalReferences.GetIndex(
                            factory.MethodEntrypoint(method.GetCanonMethodTarget(CanonicalFormKind.Specific)))));
                }

                // TODO: data to generate the generic dictionary with the type loader
                MethodDesc invokeStubMethod = factory.MetadataManager.GetReflectionInvokeStub(method);
                MethodDesc canonInvokeStubMethod = invokeStubMethod.GetCanonMethodTarget(CanonicalFormKind.Specific);
                if (invokeStubMethod != canonInvokeStubMethod)
                {
                    vertex = writer.GetTuple(vertex,
                        writer.GetUnsignedConstant(_externalReferences.GetIndex(factory.FatFunctionPointer(invokeStubMethod), FatFunctionPointerConstants.Offset) << 1));
                }
                else
                {
                    vertex = writer.GetTuple(vertex,
                        writer.GetUnsignedConstant(_externalReferences.GetIndex(factory.MethodEntrypoint(invokeStubMethod)) << 1));
                }

                if ((flags & InvokeTableFlags.IsGenericMethod) != 0)
                {
                    if ((flags & InvokeTableFlags.RequiresInstArg) == 0 || (flags & InvokeTableFlags.HasEntrypoint) == 0)
                    {
                        VertexSequence args = new VertexSequence();
                        for (int i = 0; i < method.Instantiation.Length; i++)
                        {
                            uint argId = _externalReferences.GetIndex(factory.NecessaryTypeSymbol(method.Instantiation[i]));
                            args.Append(writer.GetUnsignedConstant(argId));
//.........这里部分代码省略.........