C# NodeFactory.ConstructedTypeSymbol方法代码示例

        public override void EncodeData(ref ObjectDataBuilder dataBuilder, NodeFactory factory, bool relocsOnly)
        {
            dataBuilder.EmitZeroPointer(); // Sync block

            DefType systemStringType = factory.TypeSystemContext.GetWellKnownType(WellKnownType.String);

            //
            // The GC requires a direct reference to frozen objects' EETypes. If System.String will be compiled into a separate
            // binary, it must be cloned into this one.
            //
            if (factory.CompilationModuleGroup.ShouldReferenceThroughImportTable(systemStringType))
            {
                dataBuilder.EmitPointerReloc(factory.ConstructedClonedTypeSymbol(systemStringType));
            }
            else
            {
                dataBuilder.EmitPointerReloc(factory.ConstructedTypeSymbol(systemStringType));
            }

            dataBuilder.EmitInt(_data.Length);

            foreach (char c in _data)
            {
                dataBuilder.EmitShort((short)c);
            }

            // Null-terminate for friendliness with interop
            dataBuilder.EmitShort(0);

        }

        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 });

            ObjectDataBuilder builder = new ObjectDataBuilder(factory);

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

                var node = factory.ConstructedTypeSymbol(mappingEntry.Entity) as EETypeNode;
                
                if (node.Marked)
                {
                    // TODO: this format got very inefficient due to not being able to use RVAs
                    //       replace with a hash table

                    builder.EmitPointerReloc(node);
                    builder.EmitInt(mappingEntry.MetadataHandle);

                    if (factory.Target.PointerSize == 8)
                        builder.EmitInt(0); // Pad
                }
            }

            _endSymbol.SetSymbolOffset(builder.CountBytes);
            
            builder.DefinedSymbols.Add(this);
            builder.DefinedSymbols.Add(_endSymbol);

            return builder.ToObjectData();
        }

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
        {
            var builder = new ObjectDataBuilder(factory);

            // These need to be aligned the same as methods because they show up in same contexts
            builder.RequireAlignment(factory.Target.MinimumFunctionAlignment);

            builder.DefinedSymbols.Add(this);

            MethodDesc canonMethod = Method.GetCanonMethodTarget(CanonicalFormKind.Specific);

            // Pointer to the canonical body of the method
            builder.EmitPointerReloc(factory.MethodEntrypoint(canonMethod));

            // Find out what's the context to use
            ISymbolNode contextParameter;
            if (canonMethod.RequiresInstMethodDescArg())
            {
                contextParameter = factory.MethodGenericDictionary(Method);
            }
            else
            {
                Debug.Assert(canonMethod.RequiresInstMethodTableArg());

                // Ask for a constructed type symbol because we need the vtable to get to the dictionary
                contextParameter = factory.ConstructedTypeSymbol(Method.OwningType);
            }

            // The next entry is a pointer to the pointer to the context to be used for the canonical method
            // TODO: in multi-module, this points to the import cell, and is no longer this weird pointer
            builder.EmitPointerReloc(factory.Indirection(contextParameter));
            
            return builder.ToObjectData();
        }

        public override bool ShouldSkipEmittingObjectNode(NodeFactory factory)
        {
            // If there is a constructed version of this node in the graph, emit that instead
            if (ConstructedEETypeNode.CreationAllowed(_type))
                return ((DependencyNode)factory.ConstructedTypeSymbol(_type)).Marked;

            return false;
        }

        protected override DependencyList ComputeNonRelocationBasedDependencies(NodeFactory factory)
        {
            DefType closestDefType = _type.GetClosestDefType();

            DependencyList dependencyList = new DependencyList();
            if (_type.RuntimeInterfaces.Length > 0)
            {
                dependencyList.Add(factory.InterfaceDispatchMap(_type), "Interface dispatch map");

                // If any of the implemented interfaces have variance, calls against compatible interface methods
                // could result in interface methods of this type being used (e.g. IEnumberable<object>.GetEnumerator()
                // can dispatch to an implementation of IEnumerable<string>.GetEnumerator()).
                // For now, we will not try to optimize this and we will pretend all interface methods are necessary.
                
                foreach (var implementedInterface in _type.RuntimeInterfaces)
                {
                    if (implementedInterface.HasVariance)
                    {
                        foreach (var interfaceMethod in implementedInterface.GetAllMethods())
                        {
                            if (interfaceMethod.Signature.IsStatic)
                                continue;

                            MethodDesc implMethod = closestDefType.ResolveInterfaceMethodToVirtualMethodOnType(interfaceMethod);
                            if (implMethod != null)
                            {
                                dependencyList.Add(factory.VirtualMethodUse(interfaceMethod), "Variant interface method");
                                dependencyList.Add(factory.VirtualMethodUse(implMethod), "Variant interface method");
                            }
                        }
                    }
                }
            }

            if (_type.IsArray)
            {
                // Array EEType depends on System.Array's virtuals. Array EETypes don't point to
                // their base type (i.e. there's no reloc based dependency making this "just work").
                dependencyList.Add(factory.ConstructedTypeSymbol(_type.BaseType), "Array base type");
            }

            dependencyList.Add(factory.VTable(_type), "VTable");

            if (closestDefType.HasGenericDictionarySlot())
            {
                // Generic dictionary pointer is part of the vtable and as such it gets only laid out
                // at the final data emission phase. We need to report it as a non-relocation dependency.
                dependencyList.Add(factory.TypeGenericDictionary(closestDefType), "Type generic dictionary");
            }

            // Include the optional fields by default. We don't know if optional fields will be needed until
            // all of the interface usage has been stabilized. If we end up not needing it, the EEType node will not
            // generate any relocs to it, and the optional fields node will instruct the object writer to skip
            // emitting it.
            dependencyList.Add(_optionalFieldsNode, "Optional fields");
            
            return dependencyList;
        }

        public override bool ShouldSkipEmittingObjectNode(NodeFactory factory)
        {
            if (!_constructed)
            {
                // If there is a constructed version of this node in the graph, emit that instead
                if (((DependencyNode)factory.ConstructedTypeSymbol(_type)).Marked)
                {
                    return true;
                }
            }

            return false;
        }

        public ReadyToRunHelperNode(NodeFactory factory, ReadyToRunHelperId id, Object target)
        {
            _id = id;
            _target = target;

            switch (id)
            {
                case ReadyToRunHelperId.NewHelper:
                case ReadyToRunHelperId.NewArr1:
                    {
                        // Make sure that if the EEType can't be generated, we throw the exception now.
                        // This way we can fail generating code for the method that references the EEType
                        // and (depending on the policy), we could avoid scraping the entire compilation.
                        TypeDesc type = (TypeDesc)target;
                        factory.ConstructedTypeSymbol(type);
                    }
                    break;
                case ReadyToRunHelperId.IsInstanceOf:
                case ReadyToRunHelperId.CastClass:
                    {
                        // Make sure that if the EEType can't be generated, we throw the exception now.
                        // This way we can fail generating code for the method that references the EEType
                        // and (depending on the policy), we could avoid scraping the entire compilation.
                        TypeDesc type = (TypeDesc)target;
                        factory.NecessaryTypeSymbol(type);

                        Debug.Assert(!type.IsNullable, "Nullable needs to be unwrapped");
                    }
                    break;
                case ReadyToRunHelperId.GetNonGCStaticBase:
                case ReadyToRunHelperId.GetGCStaticBase:
                case ReadyToRunHelperId.GetThreadStaticBase:
                    {
                        // Make sure we can compute static field layout now so we can fail early
                        DefType defType = (DefType)target;
                        defType.ComputeStaticFieldLayout(StaticLayoutKind.StaticRegionSizesAndFields);
                    }
                    break;
            }
        }

        protected override DependencyList ComputeNonRelocationBasedDependencies(NodeFactory factory)
        {
            DependencyList dependencyList = new DependencyList();
            if (_type.RuntimeInterfaces.Length > 0)
            {
                dependencyList.Add(factory.InterfaceDispatchMap(_type), "Interface dispatch map");

                // If any of the implemented interfaces have variance, calls against compatible interface methods
                // could result in interface methods of this type being used (e.g. IEnumberable<object>.GetEnumerator()
                // can dispatch to an implementation of IEnumerable<string>.GetEnumerator()).
                // For now, we will not try to optimize this and we will pretend all interface methods are necessary.
                DefType defType = _type.GetClosestDefType();
                foreach (var implementedInterface in defType.RuntimeInterfaces)
                {
                    if (implementedInterface.HasVariance)
                    {
                        foreach (var interfaceMethod in implementedInterface.GetAllVirtualMethods())
                        {
                            MethodDesc implMethod = defType.ResolveInterfaceMethodToVirtualMethodOnType(interfaceMethod);
                            if (implMethod != null)
                            {
                                dependencyList.Add(factory.VirtualMethodUse(interfaceMethod), "Variant interface method");
                                dependencyList.Add(factory.VirtualMethodUse(implMethod), "Variant interface method");
                            }
                        }
                    }
                }
            }

            if (_type.IsArray)
            {
                // Array EEType depends on System.Array's virtuals. Array EETypes don't point to
                // their base type (i.e. there's no reloc based dependency making this "just work").
                dependencyList.Add(factory.ConstructedTypeSymbol(_type.BaseType), "Array base type");
            }

            dependencyList.Add(factory.VTable(_type), "VTable");

            return dependencyList;
        }

 protected override ISymbolNode GetBaseTypeNode(NodeFactory factory)
 {
     return _type.BaseType != null ? factory.ConstructedTypeSymbol(_type.BaseType) : null;
 }

        protected override void EmitCode(NodeFactory factory, ref X64Emitter encoder, bool relocsOnly)
        {
            switch (Id)
            {
                case ReadyToRunHelperId.NewHelper:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.ConstructedTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__allocate_object"));
                    break;

                case ReadyToRunHelperId.VirtualCall:
                    if (relocsOnly)
                        break;

                    AddrMode loadFromThisPtr = new AddrMode(encoder.TargetRegister.Arg0, null, 0, 0, AddrModeSize.Int64);
                    encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromThisPtr);

                    {
                        int slot = VirtualMethodSlotHelper.GetVirtualMethodSlot(factory, (MethodDesc)Target);
                        Debug.Assert(slot != -1);
                        AddrMode jmpAddrMode = new AddrMode(encoder.TargetRegister.Result, null, EETypeNode.GetVTableOffset(factory.Target.PointerSize) + (slot * factory.Target.PointerSize), 0, AddrModeSize.Int64);
                        encoder.EmitJmpToAddrMode(ref jmpAddrMode);
                    }
                    break;

                case ReadyToRunHelperId.IsInstanceOf:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__isinst_class"));
                    break;

                case ReadyToRunHelperId.CastClass:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__castclass_class"));
                    break;

                case ReadyToRunHelperId.NewArr1:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__allocate_array"));
                    break;

                case ReadyToRunHelperId.GetNonGCStaticBase:
                    if (!((MetadataType)Target).HasStaticConstructor)
                    {
                        Debug.Assert(Id == ReadyToRunHelperId.GetNonGCStaticBase);
                        encoder.EmitLEAQ(encoder.TargetRegister.Result, factory.TypeNonGCStaticsSymbol((MetadataType)Target));
                        encoder.EmitRET();
                    }
                    else
                    {
                        // We need to trigger the cctor before returning the base
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.TypeCctorContextSymbol((MetadataType)Target));
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.TypeNonGCStaticsSymbol((MetadataType)Target));
                        encoder.EmitJMP(factory.HelperEntrypoint(HelperEntrypoint.EnsureClassConstructorRunAndReturnNonGCStaticBase));
                    }
                    break;

                case ReadyToRunHelperId.GetThreadStaticBase:
                    encoder.EmitINT3();
                    break;

                case ReadyToRunHelperId.GetGCStaticBase:
                    if (!((MetadataType)Target).HasStaticConstructor)
                    {
                        encoder.EmitLEAQ(encoder.TargetRegister.Result, factory.TypeGCStaticsSymbol((MetadataType)Target));
                        AddrMode loadFromRax = new AddrMode(encoder.TargetRegister.Result, null, 0, 0, AddrModeSize.Int64);
                        encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRax);
                        encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRax);
                        encoder.EmitRET();
                    }
                    else
                    {
                        // We need to trigger the cctor before returning the base
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.TypeCctorContextSymbol((MetadataType)Target));
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.TypeGCStaticsSymbol((MetadataType)Target));
                        AddrMode loadFromRdx = new AddrMode(encoder.TargetRegister.Arg1, null, 0, 0, AddrModeSize.Int64);
                        encoder.EmitMOV(encoder.TargetRegister.Arg1, ref loadFromRdx);
                        encoder.EmitMOV(encoder.TargetRegister.Arg1, ref loadFromRdx);
                        encoder.EmitJMP(factory.HelperEntrypoint(HelperEntrypoint.EnsureClassConstructorRunAndReturnGCStaticBase));
                    }
                    break;

                case ReadyToRunHelperId.DelegateCtor:
                    {
                        DelegateInfo target = (DelegateInfo)Target;

                        encoder.EmitLEAQ(encoder.TargetRegister.Arg2, factory.MethodEntrypoint(target.Target));
                        if (target.ShuffleThunk != null)
                            encoder.EmitLEAQ(encoder.TargetRegister.Arg3, factory.MethodEntrypoint(target.ShuffleThunk));

                        encoder.EmitJMP(factory.MethodEntrypoint(target.Ctor));
                    }
                    break;

                default:
                    throw new NotImplementedException();
            }
        }

        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 });

            ObjectDataBuilder builder = new ObjectDataBuilder(factory);

            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)
                {
                    // TODO: this format got very inefficient due to not being able to use RVAs
                    //       replace with a hash table

                    builder.EmitPointerReloc(node);
                    builder.EmitInt(mappingEntry.MetadataHandle);

                    if (factory.Target.PointerSize == 8)
                        builder.EmitInt(0); // Pad
                }
            }

            _endSymbol.SetSymbolOffset(builder.CountBytes);
            
            builder.DefinedSymbols.Add(this);
            builder.DefinedSymbols.Add(_endSymbol);

            return builder.ToObjectData();
        }

        protected override void EmitCode(NodeFactory factory, ref X64Emitter encoder, bool relocsOnly)
        {
            switch (Id)
            {
                case ReadyToRunHelperId.NewHelper:
                    {
                        TypeDesc target = (TypeDesc)Target;
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.ConstructedTypeSymbol(target));
                        encoder.EmitJMP(factory.ExternSymbol(JitHelper.GetNewObjectHelperForType(target)));
                    }
                    break;

                case ReadyToRunHelperId.VirtualCall:
                    if (relocsOnly)
                        break;

                    AddrMode loadFromThisPtr = new AddrMode(encoder.TargetRegister.Arg0, null, 0, 0, AddrModeSize.Int64);
                    encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromThisPtr);

                    {
                        int slot = VirtualMethodSlotHelper.GetVirtualMethodSlot(factory, (MethodDesc)Target);
                        Debug.Assert(slot != -1);
                        AddrMode jmpAddrMode = new AddrMode(encoder.TargetRegister.Result, null, EETypeNode.GetVTableOffset(factory.Target.PointerSize) + (slot * factory.Target.PointerSize), 0, AddrModeSize.Int64);
                        encoder.EmitJmpToAddrMode(ref jmpAddrMode);
                    }
                    break;

                case ReadyToRunHelperId.IsInstanceOf:
                    {
                        TypeDesc target = (TypeDesc)Target;
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol(target));
                        encoder.EmitJMP(factory.ExternSymbol(JitHelper.GetCastingHelperNameForType(target, false)));
                    }
                    break;

                case ReadyToRunHelperId.CastClass:
                    {
                        TypeDesc target = (TypeDesc)Target;
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol(target));
                        encoder.EmitJMP(factory.ExternSymbol(JitHelper.GetCastingHelperNameForType(target, true)));
                    }
                    break;

                case ReadyToRunHelperId.NewArr1:
                    {
                        TypeDesc target = (TypeDesc)Target;


                        // TODO: Swap argument order instead
                        // mov arg1, arg0
                        encoder.Builder.EmitByte(0x48);
                        encoder.Builder.EmitShort((short)((encoder.TargetRegister.Arg0 == Register.RCX) ? 0xD18B : 0xF78B));

                        encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.NecessaryTypeSymbol(target));
                        encoder.EmitJMP(factory.ExternSymbol(JitHelper.GetNewArrayHelperForType(target)));
                    }
                    break;

                case ReadyToRunHelperId.GetNonGCStaticBase:
                    {
                        MetadataType target = (MetadataType)Target;
                        if (!target.HasStaticConstructor)
                        {
                            Debug.Assert(Id == ReadyToRunHelperId.GetNonGCStaticBase);
                            encoder.EmitLEAQ(encoder.TargetRegister.Result, factory.TypeNonGCStaticsSymbol(target));
                            encoder.EmitRET();
                        }
                        else
                        {
                            // We need to trigger the cctor before returning the base
                            encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.TypeCctorContextSymbol(target));
                            encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.TypeNonGCStaticsSymbol(target));
                            encoder.EmitJMP(factory.HelperEntrypoint(HelperEntrypoint.EnsureClassConstructorRunAndReturnNonGCStaticBase));
                        }
                    }
                    break;

                case ReadyToRunHelperId.GetThreadStaticBase:
                    encoder.EmitINT3();
                    break;

                case ReadyToRunHelperId.GetGCStaticBase:
                    {
                        MetadataType target = (MetadataType)Target;
                        if (!target.HasStaticConstructor)
                        {
                            encoder.EmitLEAQ(encoder.TargetRegister.Result, factory.TypeGCStaticsSymbol(target));
                            AddrMode loadFromRax = new AddrMode(encoder.TargetRegister.Result, null, 0, 0, AddrModeSize.Int64);
                            encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRax);
                            encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRax);
                            encoder.EmitRET();
                        }
                        else
                        {
                            // We need to trigger the cctor before returning the base
                            encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.TypeCctorContextSymbol(target));
                            encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.TypeGCStaticsSymbol(target));
                            AddrMode loadFromRdx = new AddrMode(encoder.TargetRegister.Arg1, null, 0, 0, AddrModeSize.Int64);
                            encoder.EmitMOV(encoder.TargetRegister.Arg1, ref loadFromRdx);
                            encoder.EmitMOV(encoder.TargetRegister.Arg1, ref loadFromRdx);
//.........这里部分代码省略.........

        private void OutputRelatedType(NodeFactory factory, ref ObjectDataBuilder objData)
        {
            ISymbolNode relatedTypeNode = null;

            if (_type.IsArray || _type.IsPointer)
            {
                var parameterType = ((ParameterizedType)_type).ParameterType;
                relatedTypeNode = factory.NecessaryTypeSymbol(parameterType);
            }
            else
            {
                TypeDesc baseType = _type.BaseType;
                if (baseType != null)
                {
                    if (_constructed)
                    {
                        relatedTypeNode = factory.ConstructedTypeSymbol(baseType);
                    }
                    else
                    {
                        relatedTypeNode = factory.NecessaryTypeSymbol(baseType);
                    }
                }
            }

            if (relatedTypeNode != null)
            {
                objData.EmitPointerReloc(relatedTypeNode);
            }
            else
            {
                objData.EmitZeroPointer();
            }
        }

        public override ObjectData GetData(NodeFactory factory, bool relocsOnly)
        {
            ObjectDataBuilder objData = new ObjectDataBuilder(factory);
            objData.Alignment = 16;
            objData.DefinedSymbols.Add(this);
            if (_type.IsArray)
            {
                objData.EmitShort((short)((ArrayType)_type).ElementType.GetElementSize()); // m_ComponentSize
                objData.EmitShort(0x4);                           // m_flags: IsArray(0x4)
            }
            else if (_type.IsString)
            {
                objData.EmitShort(2); // m_ComponentSize
                objData.EmitShort(0); // m_flags: 0
            }
            else
            {
                objData.EmitShort(0); // m_ComponentSize
                objData.EmitShort(0); // m_flags: 0
            }

            int pointerSize = _type.Context.Target.PointerSize;
            int minimumObjectSize = pointerSize * 3;
            int objectSize;
            if (_type is MetadataType)
            {
                objectSize = pointerSize +
                    ((MetadataType)_type).InstanceByteCount; // +pointerSize for SyncBlock
            }
            else if (_type is ArrayType)
            {
                objectSize = 3 * pointerSize; // SyncBlock + EETypePtr + Length
                int rank = ((ArrayType)_type).Rank;
                if (rank > 1)
                    objectSize +=
                        2 * _type.Context.GetWellKnownType(WellKnownType.Int32).GetElementSize() * rank;
            }
            else
                throw new NotImplementedException();

            objectSize = AlignmentHelper.AlignUp(objectSize, pointerSize);
            objectSize = Math.Max(minimumObjectSize, objectSize);

            if (_type.IsString)
            {
                // If this is a string, throw away objectSize we computed so far. Strings are special.
                // SyncBlock + EETypePtr + length + firstChar
                objectSize = 2 * pointerSize +
                    _type.Context.GetWellKnownType(WellKnownType.Int32).GetElementSize() +
                    _type.Context.GetWellKnownType(WellKnownType.Char).GetElementSize();
            }

            objData.EmitInt(objectSize);

            if (Type.BaseType != null)
            {
                if (_constructed)
                {
                    objData.EmitPointerReloc(factory.ConstructedTypeSymbol(Type.BaseType));
                }
                else
                {
                    objData.EmitPointerReloc(factory.NecessaryTypeSymbol(Type.BaseType));
                }
            }
            else
            {
                objData.EmitZeroPointer();
            }

            if (_constructed)
            {
                OutputVirtualSlots(ref objData, _type, _type, factory);
            }

            return objData.ToObjectData();
        }

        protected override void EmitCode(NodeFactory factory, ref X64Emitter encoder, bool relocsOnly)
        {
            switch (Id)
            {
                case ReadyToRunHelperId.NewHelper:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.ConstructedTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__allocate_object"));
                    break;

                case ReadyToRunHelperId.VirtualCall:
                    if (relocsOnly)
                        break;

                    AddrMode loadFromRcx = new AddrMode(encoder.TargetRegister.Arg0, null, 0, 0, AddrModeSize.Int64);
                    encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRcx);

                    // TODO: More efficient lookup of the slot
                    {
                        MethodDesc method = (MethodDesc)Target;
                        TypeDesc owningType = method.OwningType;

                        int baseSlots = 0;
                        var baseType = owningType.BaseType;

                        while (baseType != null)
                        {
                            List<MethodDesc> baseVirtualSlots;
                            factory.VirtualSlots.TryGetValue(baseType, out baseVirtualSlots);

                            if (baseVirtualSlots != null)
                                baseSlots += baseVirtualSlots.Count;
                            baseType = baseType.BaseType;
                        }

                        List<MethodDesc> virtualSlots = factory.VirtualSlots[owningType];
                        int methodSlot = -1;
                        for (int slot = 0; slot < virtualSlots.Count; slot++)
                        {
                            if (virtualSlots[slot] == method)
                            {
                                methodSlot = slot;
                                break;
                            }
                        }

                        Debug.Assert(methodSlot != -1);
                        AddrMode jmpAddrMode = new AddrMode(encoder.TargetRegister.Result, null, 16 + (baseSlots + methodSlot) * factory.Target.PointerSize, 0, AddrModeSize.Int64);
                        encoder.EmitJmpToAddrMode(ref jmpAddrMode);
                    }
                    break;

                case ReadyToRunHelperId.IsInstanceOf:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__isinst_class"));
                    break;

                case ReadyToRunHelperId.CastClass:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__castclass_class"));
                    break;

                case ReadyToRunHelperId.NewArr1:
                    encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.NecessaryTypeSymbol((TypeDesc)Target));
                    encoder.EmitJMP(factory.ExternSymbol("__allocate_array"));
                    break;

                case ReadyToRunHelperId.GetNonGCStaticBase:
                    if (!((MetadataType)Target).HasStaticConstructor)
                    {
                        Debug.Assert(Id == ReadyToRunHelperId.GetNonGCStaticBase);
                        encoder.EmitLEAQ(encoder.TargetRegister.Result, factory.TypeNonGCStaticsSymbol((MetadataType)Target));
                        encoder.EmitRET();
                    }
                    else
                    {
                        // We need to trigger the cctor before returning the base
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.TypeCctorContextSymbol((MetadataType)Target));
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.TypeNonGCStaticsSymbol((MetadataType)Target));
                        encoder.EmitJMP(factory.HelperEntrypoint(HelperEntrypoint.EnsureClassConstructorRunAndReturnNonGCStaticBase));
                    }
                    break;

                case ReadyToRunHelperId.GetThreadStaticBase:
                    encoder.EmitINT3();
                    break;

                case ReadyToRunHelperId.GetGCStaticBase:
                    if (!((MetadataType)Target).HasStaticConstructor)
                    {
                        encoder.EmitLEAQ(encoder.TargetRegister.Result, factory.TypeGCStaticsSymbol((MetadataType)Target));
                        AddrMode loadFromRax = new AddrMode(encoder.TargetRegister.Result, null, 0, 0, AddrModeSize.Int64);
                        encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRax);
                        encoder.EmitMOV(encoder.TargetRegister.Result, ref loadFromRax);
                        encoder.EmitRET();
                    }
                    else
                    {
                        // We need to trigger the cctor before returning the base
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg0, factory.TypeCctorContextSymbol((MetadataType)Target));
                        encoder.EmitLEAQ(encoder.TargetRegister.Arg1, factory.TypeGCStaticsSymbol((MetadataType)Target));
//.........这里部分代码省略.........