public static bool IsInvariantTo(this MethodBase source, MethodBase method)
{
if (source.IsGenericMethod || method.IsGenericMethod) throw new NotImplementedException(); // TODO: implement it somewhen
var me = source.GetParameters();
var he = method.GetParameters();
if (source.Ret() != method.Ret() && !source.Ret().IsAssignableFrom(method.Ret())) return false;
if (me.Length != he.Length) return false;
for (var i = 0; i < me.Length; i++)
if (he[i].ParameterType != me[i].ParameterType && !he[i].ParameterType.IsAssignableFrom(me[i].ParameterType)) return false;
return true;
}
public static MethodBuilder OverrideMethod(this TypeBuilder source, MethodBase parentMethod, Func<ILGenerator, ILGenerator> body, IDictionary<MethodBase, MethodBuilder> map)
{
// don't defer this check since default error message doesn't say
// what exact method is the reason of the failure to compile the class
parentMethod.IsVirtual.AssertTrue();
parentMethod.IsFinal.AssertFalse();
var attrs = parentMethod.Attributes;
attrs &= ~MethodAttributes.NewSlot;
attrs &= ~MethodAttributes.Abstract;
var derived = source.DefineMethod(
// that's an awesome idea but it hurts reflector and debuggability
// String.Format("{0}_{1}", parentMethod.Name, parentMethod.DeclaringType.ToShortString()),
parentMethod.Name,
attrs,
parentMethod.Ret(),
parentMethod.Params());
parentMethod.GetParameters().ForEach((pi, i) => derived.DefineParameter(i + 1, ParmA.None, pi.Name));
// the stuff below ain't necessary at all since we don't change the name
// // note. the checks are very important since otherwise we get an exception:
// // System.TypeLoadException: Signature of the body and declaration in a method implementation do not match.
// if (!parentMethod.IsAbstract && !parentMethod.IsGenericMethod)
// {
// source.DefineMethodOverride(derived, parentMethod);
// }
if (body != null) body(derived.il());
if (map != null) map[parentMethod] = derived;
return derived;
}
public static MethodBuilder DefineOverride(this TypeBuilder t, MethodBase @base)
{
MethodAttributes fixt = 0;
var allAttrs = Enum.GetValues(typeof(MethodAttributes)).Cast<MethodAttributes>();
var validAttrs = allAttrs
.Where(a => a != MethodAttributes.Abstract)
.Where(a => a != MethodAttributes.NewSlot);
validAttrs.ForEach(a => fixt |= (a & @base.Attributes));
(@base is MethodInfo).AssertTrue();
var @override = t.DefineMethod(
@base.Name,
fixt,
@base.Ret(),
@base.Params());
return @override;
}
