C# verbatim character should be removed in error messages

[leppie]

Consider the following:

[@X] class F {}

Roslyn reports that @X cannot be found, whereas the legacy compiler reports that X cannot be found.

Where spotted:

• CS0246
• CS0579
  
• CS0164
  
• CA9999

[gafter]

This is a matter of using identifier.ValueText in the error message instead of identifier.Text.

[leppie]

@gafter Easier said than done :) Consider: @List<@F>. Sadly GenericNameSyntax uses WriteTo which makes things hard.

[gafter]

We do not support generic attributes today.

[leppie]

This is not only about attributes. Consider:

class F : @List<@F> {}

Legacy compiler says: 'List' could not be found
Roslyn says: '@List<@F>' could not be found

Perhaps passing in simpleName instead of where.ToString() for Binder.NotFound will be sufficient for this case. I dont really understand why there is a whereText parameter, goes back to before Git history.

[leppie]

Passing in simpleName seems to bring it inline with the legacy compiler. But I am sure there must have been a reason for whereText. Any ideas?

[gafter]

@leppie The reason for the change from the previous (C# 5) version of the compiler is that we rewrote the compiler from scratch.

[gafter]

Pretty sure this cannot happen with CS0164 as that doesn't have any fill-ins.

[leppie]

@gafter I understand a rewrite is not easy at all. As said in previous comment, it is whereText (which is where.ToString() at the call site) that seems to be odd, and what there is no history for. There must have been some reason for it, even if it was just some workaround at some stage, but from an outsider's point of view, I cannot make that judgement. Else I would try fix it :)

[leppie]

@gafter: You are correct :) CS0164 seems to be a mistake. I picked it up from the squiggleText. My bad :)

[leppie]

@gafter Does the 3 - Working label imply someone is working on the issue?

[gafter]

Yeah... almost done.

[gafter]

Blocked by #7516