[Bug modula2/108555] gm2_langhook_option_lang_mask causes all (unappropriate) C language options to be recognized

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108555

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Iain Sandoe from comment #2)
> We do claim the ones that modula-2 actually uses in gm2-lang.opt
> 
> (previous to r13-5373-g80cf2c5e8f496b we had a large and growing set to
> accommodate everything that the preprocessor needs).
> 
> Because of that growing number of added options, this change was made
> intentionally... the idea was to claim and act on the C and Driver ones that
> are used to construct C-preprocessor command lines as an action separate
> from handling the Modula-2 options.
> 
> IIUC, the mechanism of adding them to the language opt is a convention
> rather than a correctness issue?

Kind-of ...

> Or is it that we should reject rather than ignoring the options that we do
> not pass to the preprocessor?

... yes, you are short-cutting generic code that diagnoses and removes
unappropriate options, I'm not sure simulating that behavior is easily
possible.

> (I can revert to adding everything to the gm2-lang.opt .. it just seemed a
> bit hacky)