private AccessField <object, object?> EmitFieldAccessor(FieldDefinition fieldDefinition)
{
var method = new DynamicMethod(
"AccessField",
typeof(object),
new[] { typeof(object).MakeByRefType() },
true);
method.DefineParameter(1, ParameterAttributes.Out, "target");
var generator = method.GetRobustGen();
if (Type.IsValueType)
{
generator.DeclareLocal(Type);
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldind_Ref);
generator.Emit(OpCodes.Unbox_Any, Type);
generator.Emit(OpCodes.Stloc_0);
generator.Emit(OpCodes.Ldloca_S, 0);
}
else
{
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldind_Ref);
generator.Emit(OpCodes.Castclass, Type);
}
switch (fieldDefinition.BackingField)
{
case SpecificFieldInfo field:
generator.Emit(OpCodes.Ldfld, field.FieldInfo);
break;
case SpecificPropertyInfo property:
var getter = property.PropertyInfo.GetGetMethod(true) ?? throw new NullReferenceException();
var opCode = Type.IsValueType ? OpCodes.Call : OpCodes.Callvirt;
generator.Emit(opCode, getter);
break;
}
var returnType = fieldDefinition.BackingField.FieldType;
if (returnType.IsValueType)
{
generator.Emit(OpCodes.Box, returnType);
}
generator.Emit(OpCodes.Ret);
return(method.CreateDelegate <AccessField <object, object?> >());
}
private AssignField <object, object?> EmitFieldAssigner(FieldDefinition fieldDefinition)
{
var method = new DynamicMethod(
"AssignField",
typeof(void),
new[] { typeof(object).MakeByRefType(), typeof(object) },
true);
method.DefineParameter(1, ParameterAttributes.Out, "target");
method.DefineParameter(2, ParameterAttributes.None, "value");
var generator = method.GetRobustGen();
if (Type.IsValueType)
{
generator.DeclareLocal(Type);
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldind_Ref);
generator.Emit(OpCodes.Unbox_Any, Type);
generator.Emit(OpCodes.Stloc_0);
generator.Emit(OpCodes.Ldloca, 0);
generator.Emit(OpCodes.Ldarg_1);
generator.Emit(OpCodes.Unbox_Any, fieldDefinition.FieldType);
EmitSetField(generator, fieldDefinition.BackingField);
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Box, Type);
generator.Emit(OpCodes.Stind_Ref);
generator.Emit(OpCodes.Ret);
}
else
{
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldind_Ref);
generator.Emit(OpCodes.Castclass, Type);
generator.Emit(OpCodes.Ldarg_1);
generator.Emit(OpCodes.Unbox_Any, fieldDefinition.FieldType);
EmitSetField(generator, fieldDefinition.BackingField);
generator.Emit(OpCodes.Ret);
}
return(method.CreateDelegate <AssignField <object, object?> >());
}
