private static MethodBuilder EmitBoxedSerializer(TypeBuilder type, int i, Type valueType, SerializerPair[] methodPairs)
        {
            MethodInfo dedicated = methodPairs[i].Deserialize;
            MethodBuilder boxedSerializer = type.DefineMethod("_" + i, MethodAttributes.Static, CallingConventions.Standard,
                typeof(object), new Type[] { typeof(object), typeof(ProtoReader) });
            Compiler.CompilerContext ctx = new Compiler.CompilerContext(boxedSerializer.GetILGenerator(), true, false, methodPairs);
            ctx.LoadValue(Compiler.Local.InputValue);
            Compiler.CodeLabel @null = ctx.DefineLabel();
            ctx.BranchIfFalse(@null, true);

            ctx.LoadValue(Compiler.Local.InputValue);
            ctx.CastFromObject(valueType);
            ctx.LoadReaderWriter();
            ctx.EmitCall(dedicated);
            ctx.CastToObject(valueType);
            ctx.Return();

            ctx.MarkLabel(@null);
            using(Compiler.Local typedVal = new Compiler.Local(ctx, valueType))
            {
                // create a new valueType
                ctx.LoadAddress(typedVal, valueType);
                ctx.EmitCtor(valueType);
                ctx.LoadValue(typedVal);
                ctx.LoadReaderWriter();
                ctx.EmitCall(dedicated);
                ctx.CastToObject(valueType);
                ctx.Return();
            }
            return boxedSerializer;
        }
        private static MethodBuilder EmitBoxedSerializer(TypeBuilder type, int i, Type valueType, SerializerPair[] methodPairs, TypeModel model, Compiler.CompilerContext.ILVersion ilVersion, string assemblyName)
        {
            MethodInfo dedicated = methodPairs[i].Deserialize;
            MethodBuilder boxedSerializer = type.DefineMethod("_" + i.ToString(), MethodAttributes.Static, CallingConventions.Standard,
                model.MapType(typeof(object)), new Type[] { model.MapType(typeof(object)), model.MapType(typeof(ProtoReader)) });
            Compiler.CompilerContext ctx = new Compiler.CompilerContext(boxedSerializer.GetILGenerator(), true, false, methodPairs, model, ilVersion, assemblyName, model.MapType(typeof(object)));
            ctx.LoadValue(ctx.InputValue);
            Compiler.CodeLabel @null = ctx.DefineLabel();
            ctx.BranchIfFalse(@null, true);

            Type mappedValueType = valueType;
            ctx.LoadValue(ctx.InputValue);
            ctx.CastFromObject(mappedValueType);
            ctx.LoadReaderWriter();
            ctx.EmitCall(dedicated);
            ctx.CastToObject(mappedValueType);
            ctx.Return();

            ctx.MarkLabel(@null);
            using (Compiler.Local typedVal = new Compiler.Local(ctx, mappedValueType))
            {
                // create a new valueType
                ctx.LoadAddress(typedVal, mappedValueType);
                ctx.EmitCtor(mappedValueType);
                ctx.LoadValue(typedVal);
                ctx.LoadReaderWriter();
                ctx.EmitCall(dedicated);
                ctx.CastToObject(mappedValueType);
                ctx.Return();
            }
            return boxedSerializer;
        }
Beispiel #3
0
        void IProtoSerializer.EmitRead(Compiler.CompilerContext ctx, Compiler.Local valueFrom)
        {
            Type expected = ExpectedType;

            Helpers.DebugAssert(valueFrom != null);

            using (Compiler.Local loc = ctx.GetLocalWithValue(expected, valueFrom))
                using (Compiler.Local fieldNumber = new Compiler.Local(ctx, typeof(int)))
                {
                    if (forType.IsEnum)
                    {
                        return;
                    }
                    // pre-callbacks
                    if (HasCallbacks(TypeModel.CallbackType.BeforeDeserialize))
                    {
                        Compiler.CodeLabel callbacksDone = ctx.DefineLabel();
                        ctx.LoadValue(loc);
                        ctx.BranchIfFalse(callbacksDone, false);
                        EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.BeforeDeserialize);
                        ctx.MarkLabel(callbacksDone);
                    }

                    Compiler.CodeLabel @continue = ctx.DefineLabel(), processField = ctx.DefineLabel();
                    ctx.Branch(@continue, false);

                    ctx.MarkLabel(processField);
                    foreach (BasicList.Group group in BasicList.GetContiguousGroups(fieldNumbers, serializers))
                    {
                        Compiler.CodeLabel tryNextField = ctx.DefineLabel();
                        int groupItemCount = group.Items.Count;
                        if (groupItemCount == 1)
                        {
                            // discreet group; use an equality test
                            ctx.LoadValue(fieldNumber);
                            ctx.LoadValue(group.First);
                            Compiler.CodeLabel processThisField = ctx.DefineLabel();
                            ctx.BranchIfEqual(processThisField, true);
                            ctx.Branch(tryNextField, false);
                            WriteFieldHandler(ctx, expected, loc, processThisField, @continue, (IProtoSerializer)group.Items[0]);
                        }
                        else
                        { // implement as a jump-table-based switch
                            ctx.LoadValue(fieldNumber);
                            ctx.LoadValue(group.First);
                            ctx.Subtract(); // jump-tables are zero-based
                            Compiler.CodeLabel[] jmp = new Compiler.CodeLabel[groupItemCount];
                            for (int i = 0; i < groupItemCount; i++)
                            {
                                jmp[i] = ctx.DefineLabel();
                            }
                            ctx.Switch(jmp);
                            // write the default...
                            ctx.Branch(tryNextField, false);
                            for (int i = 0; i < groupItemCount; i++)
                            {
                                WriteFieldHandler(ctx, expected, loc, jmp[i], @continue, (IProtoSerializer)group.Items[i]);
                            }
                        }
                        ctx.MarkLabel(tryNextField);
                    }

                    EmitCreateIfNull(ctx, expected, loc);
                    ctx.LoadReaderWriter();
                    if (isExtensible)
                    {
                        ctx.LoadValue(loc);
                        ctx.EmitCall(typeof(ProtoReader).GetMethod("AppendExtensionData"));
                    }
                    else
                    {
                        ctx.EmitCall(typeof(ProtoReader).GetMethod("SkipField"));
                    }

                    ctx.MarkLabel(@continue);
                    ctx.EmitBasicRead("ReadFieldHeader", typeof(int));
                    ctx.CopyValue();
                    ctx.StoreValue(fieldNumber);
                    ctx.LoadValue(0);
                    ctx.BranchIfGreater(processField, false);

                    EmitCreateIfNull(ctx, expected, loc);
                    // post-callbacks
                    EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.AfterDeserialize);
                }
        }
Beispiel #4
0
        void IProtoSerializer.EmitRead(Compiler.CompilerContext ctx, Compiler.Local valueFrom)
        {
            ProtoTypeCode typeCode = GetTypeCode();

            if (map == null)
            {
                ctx.EmitBasicRead("ReadInt32", ctx.MapType(typeof(int)));
                ctx.ConvertFromInt32(typeCode, false);
            }
            else
            {
#if TTD_LONGENUMS
                long[] wireValues = new long[map.Length];
#else
                int[] wireValues = new int[map.Length];
#endif
                object[] values = new object[map.Length];
                for (int i = 0; i < map.Length; i++)
                {
                    wireValues[i] = map[i].WireValue;
                    values[i]     = map[i].RawValue;
                }
                using (Compiler.Local result = new Compiler.Local(ctx, ExpectedType))
                    using (Compiler.Local wireValue = new Compiler.Local(ctx, ctx.MapType(typeof(int))))
                    {
                        ctx.EmitBasicRead("ReadInt32", ctx.MapType(typeof(int)));
                        ctx.StoreValue(wireValue);
                        Compiler.CodeLabel @continue = ctx.DefineLabel();
                        foreach (BasicList.Group group in BasicList.GetContiguousGroups(wireValues, values))
                        {
                            Compiler.CodeLabel tryNextGroup = ctx.DefineLabel();
                            int groupItemCount = group.Items.Count;
                            if (groupItemCount == 1)
                            {
                                // discreet group; use an equality test
                                ctx.LoadValue(wireValue);
                                ctx.LoadValue(group.First);
                                Compiler.CodeLabel processThisValue = ctx.DefineLabel();
                                ctx.BranchIfEqual(processThisValue, true);
                                ctx.Branch(tryNextGroup, false);
                                WriteEnumValue(ctx, typeCode, processThisValue, @continue, group.Items[0], @result);
                            }
                            else
                            {
                                // implement as a jump-table-based switch
                                ctx.LoadValue(wireValue);
                                ctx.LoadValue(group.First);
                                ctx.Subtract(); // jump-tables are zero-based
                                Compiler.CodeLabel[] jmp = new Compiler.CodeLabel[groupItemCount];
                                for (int i = 0; i < groupItemCount; i++)
                                {
                                    jmp[i] = ctx.DefineLabel();
                                }
                                ctx.Switch(jmp);
                                // write the default...
                                ctx.Branch(tryNextGroup, false);
                                for (int i = 0; i < groupItemCount; i++)
                                {
                                    WriteEnumValue(ctx, typeCode, jmp[i], @continue, group.Items[i], @result);
                                }
                            }
                            ctx.MarkLabel(tryNextGroup);
                        }
                        // throw source.CreateEnumException(ExpectedType, wireValue);
                        ctx.LoadReaderWriter();
                        ctx.LoadValue(ExpectedType);
                        ctx.LoadValue(wireValue);
                        ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("ThrowEnumException"));
                        ctx.MarkLabel(@continue);
                        ctx.LoadValue(result);
                    }
            }
        }
Beispiel #5
0
        public void EmitRead(Compiler.CompilerContext ctx, Compiler.Local incoming)
        {
            using (Compiler.Local objValue = ctx.GetLocalWithValue(ExpectedType, incoming))
            {
                Compiler.Local[] locals = new Compiler.Local[members.Length];
                try
                {
                    for (int i = 0; i < locals.Length; i++)
                    {
                        Type type  = GetMemberType(i);
                        bool store = true;
                        locals[i] = new Compiler.Local(ctx, type);
                        if (!ExpectedType.IsValueType)
                        {
                            // value-types always read the old value
                            if (type.IsValueType)
                            {
                                switch (Helpers.GetTypeCode(type))
                                {
                                case ProtoTypeCode.Boolean:
                                case ProtoTypeCode.Byte:
                                case ProtoTypeCode.Int16:
                                case ProtoTypeCode.Int32:
                                case ProtoTypeCode.SByte:
                                case ProtoTypeCode.UInt16:
                                case ProtoTypeCode.UInt32:
                                    ctx.LoadValue(0);
                                    break;

                                case ProtoTypeCode.Int64:
                                case ProtoTypeCode.UInt64:
                                    ctx.LoadValue(0L);
                                    break;

                                case ProtoTypeCode.Single:
                                    ctx.LoadValue(0.0F);
                                    break;

                                case ProtoTypeCode.Double:
                                    ctx.LoadValue(0.0D);
                                    break;

                                case ProtoTypeCode.Decimal:
                                    ctx.LoadValue(0M);
                                    break;

                                case ProtoTypeCode.Guid:
                                    ctx.LoadValue(Guid.Empty);
                                    break;

                                default:
                                    ctx.LoadAddress(locals[i], type);
                                    ctx.EmitCtor(type);
                                    store = false;
                                    break;
                                }
                            }
                            else
                            {
                                ctx.LoadNullRef();
                            }
                            if (store)
                            {
                                ctx.StoreValue(locals[i]);
                            }
                        }
                    }

                    Compiler.CodeLabel skipOld = ExpectedType.IsValueType
                                                        ? new Compiler.CodeLabel()
                                                        : ctx.DefineLabel();
                    if (!ExpectedType.IsValueType)
                    {
                        ctx.LoadAddress(objValue, ExpectedType);
                        ctx.BranchIfFalse(skipOld, false);
                    }
                    for (int i = 0; i < members.Length; i++)
                    {
                        ctx.LoadAddress(objValue, ExpectedType);
                        switch (members[i].MemberType)
                        {
                        case MemberTypes.Field:
                            ctx.LoadValue((FieldInfo)members[i]);
                            break;

                        case MemberTypes.Property:
                            ctx.LoadValue((PropertyInfo)members[i]);
                            break;
                        }
                        ctx.StoreValue(locals[i]);
                    }

                    if (!ExpectedType.IsValueType)
                    {
                        ctx.MarkLabel(skipOld);
                    }

                    using (Compiler.Local fieldNumber = new Compiler.Local(ctx, ctx.MapType(typeof(int))))
                    {
                        Compiler.CodeLabel @continue     = ctx.DefineLabel(),
                                           processField  = ctx.DefineLabel(),
                                           notRecognised = ctx.DefineLabel();
                        ctx.Branch(@continue, false);

                        Compiler.CodeLabel[] handlers = new Compiler.CodeLabel[members.Length];
                        for (int i = 0; i < members.Length; i++)
                        {
                            handlers[i] = ctx.DefineLabel();
                        }

                        ctx.MarkLabel(processField);

                        ctx.LoadValue(fieldNumber);
                        ctx.LoadValue(1);
                        ctx.Subtract(); // jump-table is zero-based
                        ctx.Switch(handlers);

                        // and the default:
                        ctx.Branch(notRecognised, false);
                        for (int i = 0; i < handlers.Length; i++)
                        {
                            ctx.MarkLabel(handlers[i]);
                            IProtoSerializer tail           = tails[i];
                            Compiler.Local   oldValIfNeeded = tail.RequiresOldValue ? locals[i] : null;
                            ctx.ReadNullCheckedTail(locals[i].Type, tail, oldValIfNeeded);
                            if (tail.ReturnsValue)
                            {
                                if (locals[i].Type.IsValueType)
                                {
                                    ctx.StoreValue(locals[i]);
                                }
                                else
                                {
                                    Compiler.CodeLabel hasValue = ctx.DefineLabel(), allDone = ctx.DefineLabel();

                                    ctx.CopyValue();
                                    ctx.BranchIfTrue(hasValue, true); // interpret null as "don't assign"
                                    ctx.DiscardValue();
                                    ctx.Branch(allDone, true);
                                    ctx.MarkLabel(hasValue);
                                    ctx.StoreValue(locals[i]);
                                    ctx.MarkLabel(allDone);
                                }
                            }
                            ctx.Branch(@continue, false);
                        }

                        ctx.MarkLabel(notRecognised);
                        ctx.LoadReaderWriter();
                        ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("SkipField"));

                        ctx.MarkLabel(@continue);
                        ctx.EmitBasicRead("ReadFieldHeader", ctx.MapType(typeof(int)));
                        ctx.CopyValue();
                        ctx.StoreValue(fieldNumber);
                        ctx.LoadValue(0);
                        ctx.BranchIfGreater(processField, false);
                    }
                    for (int i = 0; i < locals.Length; i++)
                    {
                        ctx.LoadValue(locals[i]);
                    }

                    ctx.EmitCtor(ctor);
                    ctx.StoreValue(objValue);
                }
                finally
                {
                    for (int i = 0; i < locals.Length; i++)
                    {
                        if (locals[i] != null)
                        {
                            locals[i].Dispose(); // release for re-use
                        }
                    }
                }
            }
        }
Beispiel #6
0
        }                                                            // updates field directly
#if FEAT_COMPILER
        void IProtoSerializer.EmitWrite(Compiler.CompilerContext ctx, Compiler.Local valueFrom)
        {
            Type expected = ExpectedType;

            using (Compiler.Local loc = ctx.GetLocalWithValue(expected, valueFrom))
            {
                if (forType.IsEnum)
                {
                    return;
                }
                // pre-callbacks
                EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.BeforeSerialize);

                Compiler.CodeLabel startFields = ctx.DefineLabel();
                // inheritance
                if (CanHaveInheritance)
                {
                    for (int i = 0; i < serializers.Length; i++)
                    {
                        IProtoSerializer ser = serializers[i];
                        if (ser.ExpectedType != forType)
                        {
                            Compiler.CodeLabel ifMatch = ctx.DefineLabel(), nextTest = ctx.DefineLabel();
                            ctx.LoadValue(loc);
                            ctx.TryCast(ser.ExpectedType);
                            ctx.CopyValue();
                            ctx.BranchIfTrue(ifMatch, true);
                            ctx.DiscardValue();
                            ctx.Branch(nextTest, true);
                            ctx.MarkLabel(ifMatch);
                            ser.EmitWrite(ctx, null);
                            ctx.Branch(startFields, false);
                            ctx.MarkLabel(nextTest);
                        }
                    }


                    if (constructType != null && constructType != forType)
                    {
                        using (Compiler.Local actualType = new Compiler.Local(ctx, typeof(Type)))
                        {
                            // would have jumped to "fields" if an expected sub-type, so two options:
                            // a: *exactly* that type, b: an *unexpected* type
                            ctx.LoadValue(loc);
                            ctx.EmitCall(typeof(object).GetMethod("GetType"));
                            ctx.CopyValue();
                            ctx.StoreValue(actualType);
                            ctx.LoadValue(forType);
                            ctx.BranchIfEqual(startFields, true);

                            ctx.LoadValue(actualType);
                            ctx.LoadValue(constructType);
                            ctx.BranchIfEqual(startFields, true);
                        }
                    }
                    else
                    {
                        // would have jumped to "fields" if an expected sub-type, so two options:
                        // a: *exactly* that type, b: an *unexpected* type
                        ctx.LoadValue(loc);
                        ctx.EmitCall(typeof(object).GetMethod("GetType"));
                        ctx.LoadValue(forType);
                        ctx.BranchIfEqual(startFields, true);
                    }
                    // unexpected, then... note that this *might* be a proxy, which
                    // is handled by ThrowUnexpectedSubtype
                    ctx.LoadValue(forType);
                    ctx.LoadValue(loc);
                    ctx.EmitCall(typeof(object).GetMethod("GetType"));
                    ctx.EmitCall(typeof(TypeModel).GetMethod("ThrowUnexpectedSubtype",
                                                             BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static));
                }
                // fields

                ctx.MarkLabel(startFields);
                for (int i = 0; i < serializers.Length; i++)
                {
                    IProtoSerializer ser = serializers[i];
                    if (ser.ExpectedType == forType)
                    {
                        ser.EmitWrite(ctx, loc);
                    }
                }

                // extension data
                if (isExtensible)
                {
                    ctx.LoadValue(loc);
                    ctx.LoadReaderWriter();
                    ctx.EmitCall(typeof(ProtoWriter).GetMethod("AppendExtensionData"));
                }
                // post-callbacks
                EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.AfterSerialize);
            }
        }
        void IProtoSerializer.EmitRead(Compiler.CompilerContext ctx, Compiler.Local valueFrom)
        {
            using (ctx.StartDebugBlockAuto(this))
            {
                var g = ctx.G;
                Helpers.DebugAssert(!valueFrom.IsNullRef());

                using (Compiler.Local loc = ctx.GetLocalWithValueForEmitRead(this, valueFrom))
                    using (Compiler.Local token = ctx.Local(typeof(SubItemToken)))
                        using (Compiler.Local fieldNumber = new Compiler.Local(ctx, ctx.MapType(typeof(int))))
                        {
                            g.Assign(token, g.ReaderFunc.StartSubItem());
                            // pre-callbacks
                            if (HasCallbacks(TypeModel.CallbackType.BeforeDeserialize))
                            {
                                if (ExpectedType.IsValueType)
                                {
                                    EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.BeforeDeserialize);
                                }
                                else
                                { // could be null
                                    Compiler.CodeLabel callbacksDone = ctx.DefineLabel();
                                    ctx.LoadValue(loc);
                                    ctx.BranchIfFalse(callbacksDone, false);
                                    EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.BeforeDeserialize);
                                    ctx.MarkLabel(callbacksDone);
                                }
                            }

                            Compiler.CodeLabel @continue = ctx.DefineLabel(), processField = ctx.DefineLabel();
                            ctx.Branch(@continue, false);

                            ctx.MarkLabel(processField);
                            foreach (BasicList.Group group in BasicList.GetContiguousGroups(_fieldNumbers, _serializers))
                            {
                                Compiler.CodeLabel tryNextField = ctx.DefineLabel();
                                int groupItemCount = group.Items.Count;
                                if (groupItemCount == 1)
                                {
                                    // discreet group; use an equality test
                                    ctx.LoadValue(fieldNumber);
                                    ctx.LoadValue(group.First);
                                    Compiler.CodeLabel processThisField = ctx.DefineLabel();
                                    ctx.BranchIfEqual(processThisField, true);
                                    ctx.Branch(tryNextField, false);
                                    WriteFieldHandler(ctx, loc, processThisField, @continue, (IProtoSerializer)group.Items[0]);
                                }
                                else
                                { // implement as a jump-table-based switch
                                    ctx.LoadValue(fieldNumber);
                                    ctx.LoadValue(group.First);
                                    ctx.Subtract(); // jump-tables are zero-based
                                    Compiler.CodeLabel[] jmp = new Compiler.CodeLabel[groupItemCount];
                                    for (int i = 0; i < groupItemCount; i++)
                                    {
                                        jmp[i] = ctx.DefineLabel();
                                    }
                                    ctx.Switch(jmp);
                                    // write the default...
                                    ctx.Branch(tryNextField, false);
                                    for (int i = 0; i < groupItemCount; i++)
                                    {
                                        WriteFieldHandler(ctx, loc, jmp[i], @continue, (IProtoSerializer)group.Items[i]);
                                    }
                                }
                                ctx.MarkLabel(tryNextField);
                            }

                            EmitCreateIfNull(ctx, loc);
                            ctx.LoadReaderWriter();
                            if (_isExtensible)
                            {
                                ctx.LoadValue(loc);
                                ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("AppendExtensionData"));
                            }
                            else
                            {
                                ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("SkipField"));
                            }

                            ctx.MarkLabel(@continue);
                            ctx.EmitBasicRead("ReadFieldHeader", ctx.MapType(typeof(int)));
                            ctx.CopyValue();
                            ctx.StoreValue(fieldNumber);
                            ctx.LoadValue(0);
                            ctx.BranchIfGreater(processField, false);

                            EmitCreateIfNull(ctx, loc);
                            // post-callbacks
                            EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.AfterDeserialize);

                            g.Reader.EndSubItem(token);

                            if (EmitReadReturnsValue)
                            {
                                ctx.LoadValue(loc);
                            }
                        }
            }
        }
        private void WriteFieldHandler(
            Compiler.CompilerContext ctx, Type expected, Compiler.Local loc,
            Compiler.CodeLabel handler, Compiler.CodeLabel @continue, IProtoSerializer serializer)
        {
            ctx.MarkLabel(handler);
            Type serType = serializer.ExpectedType;

            if (serType == forType)
            {
                EmitCreateIfNull(ctx, loc);
                serializer.EmitRead(ctx, loc);
            }
            else
            {
                //RuntimeTypeModel rtm = (RuntimeTypeModel)ctx.Model;
                if (((IProtoTypeSerializer)serializer).CanCreateInstance())
                {
                    Compiler.CodeLabel allDone = ctx.DefineLabel();

                    ctx.LoadValue(loc);
                    ctx.BranchIfFalse(allDone, false); // null is always ok

                    ctx.LoadValue(loc);
                    ctx.TryCast(serType);
                    ctx.BranchIfTrue(allDone, false); // not null, but of the correct type

                    // otherwise, need to convert it
                    ctx.LoadReaderWriter();
                    ctx.LoadValue(loc);
                    ((IProtoTypeSerializer)serializer).EmitCreateInstance(ctx);
                    ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("Merge"));
                    ctx.Cast(expected);
                    ctx.StoreValue(loc); // Merge always returns a value

                    // nothing needs doing
                    ctx.MarkLabel(allDone);
                }

                if (Helpers.IsValueType(serType))
                {
                    Compiler.CodeLabel initValue = ctx.DefineLabel();
                    Compiler.CodeLabel hasValue  = ctx.DefineLabel();
                    using (Compiler.Local emptyValue = new Compiler.Local(ctx, serType))
                    {
                        ctx.LoadValue(loc);
                        ctx.BranchIfFalse(initValue, false);

                        ctx.LoadValue(loc);
                        ctx.CastFromObject(serType);
                        ctx.Branch(hasValue, false);

                        ctx.MarkLabel(initValue);
                        ctx.InitLocal(serType, emptyValue);
                        ctx.LoadValue(emptyValue);

                        ctx.MarkLabel(hasValue);
                    }
                }
                else
                {
                    ctx.LoadValue(loc);
                    ctx.Cast(serType);
                }

                serializer.EmitRead(ctx, null);
            }

            if (serializer.ReturnsValue)
            {   // update the variable
                if (Helpers.IsValueType(serType))
                {
                    // but box it first in case of value type
                    ctx.CastToObject(serType);
                }
                ctx.StoreValue(loc);
            }
            ctx.Branch(@continue, false); // "continue"
        }
        } = false;                                         // updates field directly

        void IProtoSerializer.EmitWrite(Compiler.CompilerContext ctx, Compiler.Local valueFrom)
        {
            using (ctx.StartDebugBlockAuto(this))
            {
                var  g        = ctx.G;
                Type expected = ExpectedType;
                using (Compiler.Local loc = ctx.GetLocalWithValue(expected, valueFrom))
                    using (Compiler.Local token = ctx.Local(typeof(SubItemToken)))
                    {
                        g.Assign(token, g.WriterFunc.StartSubItem(loc, _prefixLength));
                        // pre-callbacks
                        EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.BeforeSerialize);

                        Compiler.CodeLabel startFields = ctx.DefineLabel();
                        // inheritance
                        if (CanHaveInheritance)
                        {
                            for (int i = 0; i < _serializers.Length; i++)
                            {
                                IProtoSerializer ser     = _serializers[i];
                                Type             serType = ser.ExpectedType;
                                if (serType != ExpectedType)
                                {
                                    Compiler.CodeLabel ifMatch = ctx.DefineLabel(), nextTest = ctx.DefineLabel();
                                    ctx.LoadValue(loc);
                                    ctx.TryCast(serType);
                                    ctx.CopyValue();
                                    ctx.BranchIfTrue(ifMatch, true);
                                    ctx.DiscardValue();
                                    ctx.Branch(nextTest, true);
                                    ctx.MarkLabel(ifMatch);
                                    ctx.G.Writer.WriteFieldHeaderBegin(_fieldNumbers[i]);
                                    ser.EmitWrite(ctx, null);
                                    ctx.Branch(startFields, false);
                                    ctx.MarkLabel(nextTest);
                                }
                            }


                            if (_constructType != null && _constructType != ExpectedType)
                            {
                                using (Compiler.Local actualType = new Compiler.Local(ctx, ctx.MapType(typeof(System.Type))))
                                {
                                    // would have jumped to "fields" if an expected sub-type, so two options:
                                    // a: *exactly* that type, b: an *unexpected* type
                                    ctx.LoadValue(loc);
                                    ctx.EmitCall(ctx.MapType(typeof(object)).GetMethod("GetType"));
                                    ctx.CopyValue();
                                    ctx.StoreValue(actualType);
                                    ctx.LoadValue(ExpectedType);
                                    ctx.BranchIfEqual(startFields, true);

                                    ctx.LoadValue(actualType);
                                    ctx.LoadValue(_constructType);
                                    ctx.BranchIfEqual(startFields, true);
                                }
                            }
                            else
                            {
                                // would have jumped to "fields" if an expected sub-type, so two options:
                                // a: *exactly* that type, b: an *unexpected* type
                                ctx.LoadValue(loc);
                                ctx.EmitCall(ctx.MapType(typeof(object)).GetMethod("GetType"));
                                ctx.LoadValue(ExpectedType);
                                ctx.BranchIfEqual(startFields, true);
                            }
                            // unexpected, then... note that this *might* be a proxy, which
                            // is handled by ThrowUnexpectedSubtype
                            ctx.LoadValue(ExpectedType);
                            ctx.LoadValue(loc);
                            ctx.EmitCall(ctx.MapType(typeof(object)).GetMethod("GetType"));
                            ctx.EmitCall(
                                ctx.MapType(typeof(TypeModel)).GetMethod(
                                    "ThrowUnexpectedSubtype",
                                    BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static));
                        }
                        // fields

                        ctx.MarkLabel(startFields);
                        for (int i = 0; i < _serializers.Length; i++)
                        {
                            IProtoSerializer ser = _serializers[i];
                            if (ser.ExpectedType == ExpectedType)
                            {
                                ctx.G.Writer.WriteFieldHeaderBegin(_fieldNumbers[i]);
                                ser.EmitWrite(ctx, loc);
                            }
                        }

                        // extension data
                        if (_isExtensible)
                        {
                            ctx.LoadValue(loc);
                            ctx.LoadReaderWriter();
                            ctx.EmitCall(ctx.MapType(typeof(ProtoWriter)).GetMethod("AppendExtensionData"));
                        }
                        // post-callbacks
                        EmitCallbackIfNeeded(ctx, loc, TypeModel.CallbackType.AfterSerialize);
                        g.Writer.EndSubItem(token);
                    }
            }
        }
        void IProtoTypeSerializer.EmitCreateInstance(Compiler.CompilerContext ctx)

        {
            // different ways of creating a new instance

            bool callNoteObject = true;

            if (factory != null)

            {
                EmitInvokeCallback(ctx, factory, false, constructType, forType);
            }

            else if (!useConstructor)

            {   // DataContractSerializer style
                ctx.LoadValue(constructType);

                ctx.EmitCall(ctx.MapType(typeof(BclHelpers)).GetMethod("GetUninitializedObject"));

                ctx.Cast(forType);
            }

            else if (constructType.IsClass && hasConstructor)

            {   // XmlSerializer style
                ctx.EmitCtor(constructType);
            }

            else

            {
                ctx.LoadValue(ExpectedType);

                ctx.EmitCall(ctx.MapType(typeof(TypeModel)).GetMethod("ThrowCannotCreateInstance",

                                                                      BindingFlags.Static | BindingFlags.Public));

                ctx.LoadNullRef();

                callNoteObject = false;
            }

            if (callNoteObject)

            {
                // track root object creation

                ctx.CopyValue();

                ctx.LoadReaderWriter();

                ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("NoteObject",

                                                                        BindingFlags.Static | BindingFlags.Public));
            }

            if (baseCtorCallbacks != null)

            {
                for (int i = 0; i < baseCtorCallbacks.Length; i++)

                {
                    EmitInvokeCallback(ctx, baseCtorCallbacks[i], true, null, forType);
                }
            }
        }
        bool EmitDedicatedMethod(Compiler.CompilerContext ctx, Compiler.Local valueFrom, bool read)

        {
#if SILVERLIGHT
            return(false);
#else
            MethodBuilder method = ctx.GetDedicatedMethod(key, read);

            if (method == null)
            {
                return(false);
            }



            using (Compiler.Local token = new ProtoBuf.Compiler.Local(ctx, ctx.MapType(typeof(SubItemToken))))

            {
                Type rwType = ctx.MapType(read ? typeof(ProtoReader) : typeof(ProtoWriter));

                ctx.LoadValue(valueFrom);

                if (!read) // write requires the object for StartSubItem; read doesn't

                {          // (if recursion-check is disabled [subtypes] then null is fine too)
                    if (type.IsValueType || !recursionCheck)
                    {
                        ctx.LoadNullRef();
                    }

                    else
                    {
                        ctx.CopyValue();
                    }
                }

                ctx.LoadReaderWriter();

                ctx.EmitCall(rwType.GetMethod("StartSubItem"));

                ctx.StoreValue(token);



                // note: value already on the stack

                ctx.LoadReaderWriter();

                ctx.EmitCall(method);

                // handle inheritance (we will be calling the *base* version of things,

                // but we expect Read to return the "type" type)

                if (read && type != method.ReturnType)
                {
                    ctx.Cast(this.type);
                }

                ctx.LoadValue(token);



                ctx.LoadReaderWriter();

                ctx.EmitCall(rwType.GetMethod("EndSubItem"));
            }

            return(true);
#endif
        }
        protected override void EmitRead(Compiler.CompilerContext ctx, Compiler.Local valueFrom)

        {
            using (Compiler.Local oldValue = ctx.GetLocalWithValue(expectedType, valueFrom))

                using (Compiler.Local token = new Compiler.Local(ctx, ctx.MapType(typeof(SubItemToken))))

                    using (Compiler.Local field = new Compiler.Local(ctx, ctx.MapType(typeof(int))))

                    {
                        ctx.LoadReaderWriter();

                        ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("StartSubItem"));

                        ctx.StoreValue(token);



                        Compiler.CodeLabel next = ctx.DefineLabel(), processField = ctx.DefineLabel(), end = ctx.DefineLabel();



                        ctx.MarkLabel(next);



                        ctx.EmitBasicRead("ReadFieldHeader", ctx.MapType(typeof(int)));

                        ctx.CopyValue();

                        ctx.StoreValue(field);

                        ctx.LoadValue(Tag); // = 1 - process

                        ctx.BranchIfEqual(processField, true);

                        ctx.LoadValue(field);

                        ctx.LoadValue(1); // < 1 - exit

                        ctx.BranchIfLess(end, false);



                        // default: skip

                        ctx.LoadReaderWriter();

                        ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("SkipField"));

                        ctx.Branch(next, true);



                        // process

                        ctx.MarkLabel(processField);

                        if (Tail.RequiresOldValue)

                        {
                            if (expectedType.IsValueType)

                            {
                                ctx.LoadAddress(oldValue, expectedType);

                                ctx.EmitCall(expectedType.GetMethod("GetValueOrDefault", Helpers.EmptyTypes));
                            }

                            else

                            {
                                ctx.LoadValue(oldValue);
                            }
                        }

                        Tail.EmitRead(ctx, null);

                        // note we demanded always returns a value

                        if (expectedType.IsValueType)

                        {
                            ctx.EmitCtor(expectedType, Tail.ExpectedType); // re-nullable<T> it
                        }

                        ctx.StoreValue(oldValue);

                        ctx.Branch(next, false);



                        // outro

                        ctx.MarkLabel(end);



                        ctx.LoadValue(token);

                        ctx.LoadReaderWriter();

                        ctx.EmitCall(ctx.MapType(typeof(ProtoReader)).GetMethod("EndSubItem"));

                        ctx.LoadValue(oldValue); // load the old value
                    }
        }
        protected override void EmitWrite(Compiler.CompilerContext ctx, Compiler.Local valueFrom)

        {
            using (Compiler.Local valOrNull = ctx.GetLocalWithValue(expectedType, valueFrom))

                using (Compiler.Local token = new Compiler.Local(ctx, ctx.MapType(typeof(SubItemToken))))

                {
                    ctx.LoadNullRef();

                    ctx.LoadReaderWriter();

                    ctx.EmitCall(ctx.MapType(typeof(ProtoWriter)).GetMethod("StartSubItem"));

                    ctx.StoreValue(token);



                    if (expectedType.IsValueType)

                    {
                        ctx.LoadAddress(valOrNull, expectedType);

                        ctx.LoadValue(expectedType.GetProperty("HasValue"));
                    }

                    else

                    {
                        ctx.LoadValue(valOrNull);
                    }

                    Compiler.CodeLabel @end = ctx.DefineLabel();

                    ctx.BranchIfFalse(@end, false);

                    if (expectedType.IsValueType)

                    {
                        ctx.LoadAddress(valOrNull, expectedType);

                        ctx.EmitCall(expectedType.GetMethod("GetValueOrDefault", Helpers.EmptyTypes));
                    }

                    else

                    {
                        ctx.LoadValue(valOrNull);
                    }

                    Tail.EmitWrite(ctx, null);



                    ctx.MarkLabel(@end);



                    ctx.LoadValue(token);

                    ctx.LoadReaderWriter();

                    ctx.EmitCall(ctx.MapType(typeof(ProtoWriter)).GetMethod("EndSubItem"));
                }
        }