private void EnsureLabelAndValue()
{
if (!_labelDefined)
{
_labelDefined = true;
_label = _ilg.DefineLabel();
if (_node != null && _node.Type != typeof(void))
{
_value = _ilg.DeclareLocal(_node.Type);
}
}
}
private static void EmitNullableToNullableConversion(this ILGenerator il, Type typeFrom, Type typeTo, bool isChecked)
{
Debug.Assert(TypeUtils.IsNullableType(typeFrom));
Debug.Assert(TypeUtils.IsNullableType(typeTo));
Label labIfNull = default(Label);
Label labEnd = default(Label);
LocalBuilder locFrom = null;
LocalBuilder locTo = null;
locFrom = il.DeclareLocal(typeFrom);
il.Emit(OpCodes.Stloc, locFrom);
locTo = il.DeclareLocal(typeTo);
// test for null
il.Emit(OpCodes.Ldloca, locFrom);
il.EmitHasValue(typeFrom);
labIfNull = il.DefineLabel();
il.Emit(OpCodes.Brfalse_S, labIfNull);
il.Emit(OpCodes.Ldloca, locFrom);
il.EmitGetValueOrDefault(typeFrom);
Type nnTypeFrom = TypeUtils.GetNonNullableType(typeFrom);
Type nnTypeTo = TypeUtils.GetNonNullableType(typeTo);
il.EmitConvertToType(nnTypeFrom, nnTypeTo, isChecked);
// construct result type
ConstructorInfo ci = typeTo.GetConstructor(new Type[] { nnTypeTo });
il.Emit(OpCodes.Newobj, ci);
il.Emit(OpCodes.Stloc, locTo);
labEnd = il.DefineLabel();
il.Emit(OpCodes.Br_S, labEnd);
// if null then create a default one
il.MarkLabel(labIfNull);
il.Emit(OpCodes.Ldloca, locTo);
il.Emit(OpCodes.Initobj, typeTo);
il.MarkLabel(labEnd);
il.Emit(OpCodes.Ldloc, locTo);
}
