Re: [PATCH 1/2] gcc/file-prefix-map: Allow remapping of relative paths

[Eric Botcazou via Gcc-patches]

> I can send the obvious patch to make it work as before and ignore the
> NULL which fixes this. I'm not sure if it should really be passing NULL
> around in the first place or not which is why I'm sharing the backtrace.

Thanks for the investigation.  That's because the DECL_SOURCE_LOCATION of the 
function is UNKNOWN_LOCATION since:

2021-08-11  Bernd Edlinger  <bernd.edlin...@hotmail.de>

        PR debug/101598
        * gcc-interface/trans.c (Subprogram_Body_to_gnu): Set the
        DECL_SOURCE_LOCATION of DECL_IGNORED_P gnu_subprog_decl to
        UNKNOWN_LOCATION.

That's indeed quite irregular but we have to live with it now.

-- 
Eric Botcazou