Re: Request easy bug fix

[Jonathan Wakely <jwakely.gcc@gmail.com>]

On Tue, 15 Feb 2022 at 13:58, David Malcolm <dmalcolm@redhat.com> wrote:

> On Tue, 2022-02-15 at 12:55 +0000, Jonathan Wakely via Gcc wrote:
> > On Tue, 15 Feb 2022 at 12:34, Baruch Burstein via Gcc <
> > gcc@gcc.gnu.org>
> > wrote:
> >
> > > Hi,
> > >
> > > I hope it is not inappropriate to call attention to a specific bug.
> > > https://gcc.gnu.org/bugzilla//show_bug.cgi?id=85487.
> > > I tried to do it myself, but got lost on the part where I needed to
> > > compile gcc 3 times and compare test results to some (un)known test
> > > results.
>
> Thanks for trying to fix the bug.
>
> >
> >
> > You compare the test results of your patched gcc to the test results
> > of an
> > unpatched gcc.
> >
> > How did you get lost? To "compile gcc 3 times" you just run "make",
> > and it
> > does that automatically (unless you configured with --disable-
> > bootstrap, in
> > which case it just compiles once).
>
> Jonathan, if I may: you're extremely familiar with hacking on GCC, and
> I think that familiarity is leading you to underestimate the learning
> curve for someone new getting involved in GCC development.
>
> As you say, --disable-bootstrap is the configure-time option to use
> when working on a new patch, since it avoids the "compile 3 times"
> cycle.  We could probably document that better.
>

Agreed. So it would help to know which docs Baruch was looking at when
getting lost. There's no point adding *more* docs if we already have some
that are doing more harm than good.


>
> >
> >
> > > It was too much time and setup for a fix that will probably
> > > take 2 minutes to implement, so I am asking if someone that already
> > > contributes to gcc can please look at this. I think it should only
> > > take a couple of minutes to implement.
>
> Baruch: here you are underestimating the time that adding a new feature
> takes; yes, it perhaps could take about 2 minutes to get a minimal
> proof-of-concept working, but once you start adding documentation,
> test-cases, etc it becomes more than that.  Also, looking at the
> discussion now happening in the bug report, it's not clear that the
> absolute minimum implementation is the correct one
>
> I'm guessing that you care because you're working in a mixed Visual
> Studio/GCC environment, and have a codebase with these pragmas.
> Does Visual Studio complain about mismatches, or incorrect nesting?
> If so, can you give some more information about these interoperability
> issues being discussed in the bug report?
> (I used to work in such an environment, but that was over 20 years ago;
> my knowledge of Visual Studio is *very* out of date, sorry)
>

Clang and the MSVC compiler both ignore any tokens after the pragma, so
that seems good enough for GCC too:

https://godbolt.org/z/norv947a5