/// <summary>
/// Generates IL to read a single item from the stream and leaves the result on the stack.
/// </summary>
/// <param name="type">The <see cref="Type"/> of item to read.</param>
/// <param name="args">The arguments for generating the il.</param>
void GenerateReadTypeIL(Type type, GenerateArgs args)
{
MethodInfo method = GetTypeMethod(type, TypeMethodType.Deserialize);
DynamicMethodHelper il = args.il;
bool dynamic = IsDynamic && (type.IsValueType == false);
// Variable names
const string valueVar = "_readValue";
const string dynamicTypeIndexVar = "_typeIndex";
const string dynamicTypeVar = "_dynamicType";
const string dynamicTypeNameVar = "_dynamicTypeName";
const string dynamicTypeResolvedLabel = "_dynamicTypeResolved";
const string dynamicTypeNotNullLabel = "_dynamicTypeNotNull";
const string dynamicTypeDoneLabel = "_dynamicTypeDone";
il.BeginScope();
{
if (dynamic)
{
il.DeclareLocal(dynamicTypeIndexVar, typeof(byte));
il.DeclareLocal(valueVar, typeof(object));
il.DeclareLocal(dynamicTypeNameVar, typeof(string));
il.DeclareLocal(dynamicTypeVar, typeof(Type));
// Read type index
il.PushLocal(args.streamVar);
il.CallMethod(GetTypeMethod(typeof(byte), TypeMethodType.Deserialize));
il.PopLocal(dynamicTypeIndexVar);
// if (typeIndex == -1) goto :dynamicInstanceNull
il.PushLocal(dynamicTypeIndexVar);
il.PushInt(SerializerHeaders.NullVersion);
il.GotoIfNotEqual(dynamicTypeNotNullLabel);
// return null
// goto :dynamicTypeDone
il.PushNull();
il.Goto(dynamicTypeDoneLabel);
// :dynamicTypeNotNull
il.MarkLabel(dynamicTypeNotNullLabel);
// Get type info for typeIndex
il.PushLocal(args.nameTableVar);
il.PushLocal(dynamicTypeIndexVar);
il.PushLocalAsRef(dynamicTypeVar);
il.PushLocalAsRef(dynamicTypeNameVar);
il.CallMethod(typeof(TypeNameTable).GetMethod("GetTypeInfo"));
// If (type != null) goto :typeResolved
il.PushLocal(dynamicTypeVar);
il.GotoIfTrue(dynamicTypeResolvedLabel);
// Call Type.GetType to resolve type. We must do this
// in the context of the type being deserialized to
// get the appropriate visibility permissions
il.PushLocal(dynamicTypeNameVar);
il.PushBool(true);
il.CallMethod(typeof(Type).GetMethod(
"GetType",
BindingFlags.Static | BindingFlags.Public,
null,
new [] { typeof(string), typeof(bool) },
null
));
il.PopLocal(dynamicTypeVar);
// Save the resolved type back to the type table so
// subsequent instances of the same type don't have to
// do it again
il.PushLocal(args.nameTableVar);
il.PushLocal(dynamicTypeIndexVar);
il.PushLocal(dynamicTypeVar);
il.CallMethod(typeof(TypeNameTable).GetMethod("SetResolvedType"));
// :typeResolved
il.MarkLabel(dynamicTypeResolvedLabel);
// Create an empty instance of the resolved type
il.PushLocal(dynamicTypeVar);
il.PushBool(true);
il.CallMethod(typeof(Activator).GetMethod(
"CreateInstance",
new [] { typeof(Type), typeof(bool) }
));
il.PopLocal(valueVar);
// Call the serializer to read it
il.PushLocalAsRef(valueVar);
il.PushArg(args.dataArg);
il.CallMethod(method);
il.Pop();
// return (baseType)dynamicInstance
il.PushLocal(valueVar);
il.Cast(type);
// :dynamicTypeDone
il.MarkLabel(dynamicTypeDoneLabel);
}
else if (method.DeclaringType == typeof(IPrimitiveReader))
{
// return reader.ReadXXXX()
il.PushLocal(args.streamVar);
il.CallMethod(method);
}
else //if (type.IsClass)
{
// Create empty instance of type
il.DeclareLocal(valueVar, typeof(object));
if (type.IsClass)
{
il.NewObject(valueVar, type, Type.EmptyTypes);
}
// Call the serializer to read it
il.PushLocalAsRef(valueVar);
il.PushArg(args.dataArg);
il.CallMethod(method);
il.Pop(); // Ignore return value
// return (type)instance
il.PushLocal(valueVar);
if (type.IsClass)
{
il.Cast(type);
}
else
{
il.UnboxValueType(type);
}
}
}
il.EndScope();
}