preprocessor/21250 and address of <built-in>

[Zack Weinberg]

Per Bothner <per@bothner.com> writes:

...
> However, we end up with preprocessor output like this:
>
> # 1 "any-file"
> # 0 "<built-in>"
> # 1 "<command line>"
> # 1 "any-file"
>
> Some assemblers complain about line number 0.  This is especially
> an issue for people who use cpp to preprocessor assembler, which
> of course we don't really support.
>
> My suggested solution: suppress the output of <built-in>, so
> we get:
> # 1 "any-file"
> # 1 "<command line>"
> # 1 "any-file"
>
> There should never be anything following <built-in>, so it's useless
> as well as confusing. 

Stuff does appear between <built-in> and <command line> with -g3, -dD,
and possibly some of the other -d switches.  That is why they're
there.  I would have no objection to suppressing it (and <command line> 
too) when none of those options is in use.

zw