Re: [PATCH] Always default to DWARF2_DEBUG if not specified, warn about deprecated STABS

[Richard Biener <richard.guenther@gmail.com>]

On Wed, Sep 7, 2022 at 12:51 PM Jan-Benedict Glaw <jbglaw@lug-owl.de> wrote:
>
> Hi!
>
> On Mon, 2022-08-29 22:11:35 +0200, Jan-Benedict Glaw <jbglaw@lug-owl.de> wrote:
> > On Sun, 2022-08-28 15:32:53 -0600, Jeff Law via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > > On 8/28/2022 1:50 AM, Jan-Benedict Glaw wrote:
> > > > On Tue, 2021-09-21 16:25:19 +0200, Richard Biener via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > > > > This makes defaults.h choose DWARF2_DEBUG if PREFERRED_DEBUGGING_TYPE
> > > > > is not specified by the target and errors out if DWARF DWARF is not supported.
> > > > While I think the pdp11 bits arreved, the rest did not (yet). Just
> > > > checked my auto-builder logs. When building current HEAD as
> > > >
> > > >   ../gcc/configure --prefix=... --enable-werror-always \
> > > >           --enable-languages=all --disable-gcov \
> > > >           --disable-shared --disable-threads --without-headers \
> > > >           --target=...
> > > >   make V=1 all-gcc
> > > >
> > > > ALL of these targets won't build right now:
> > [...]
> > > Umm, most of those -elf targets do build.  See:
> > >
> > > http://law-sandy.freeddns.org:8080
> >
> > Another builder. :)  Randomly picking xtensa-elf, you're configuring
> > as
> >
> > + ../../gcc/configure --disable-analyzer --with-system-libunwind
> > --with-newlib --without-headers --disable-threads --disable-shared
> > --enable-languages=c,c++
> > --prefix=/home/jlaw/jenkins/workspace/xtensa-elf/xtensa-elf-obj/gcc/../../xtensa-elf-installed
> > --target=xtensa-elf
> >
> > I guess the main difference that lets my builds fail might be
> > --enable-languages=all (vs. c,c++ in your case.)
> >
> > Maybe you'd give that a try? (...and I'll trigger a build with just
> > c,c++ on my builder.)
>
> So ... just building for --enable-languages=c,c++ usually works for
> the *-elf targets, but I'm interested in building as much code as
> possible. Is it expected that with --enable-languages=all, all those
> targets will break? Can we have a sane default here, or need the
> maintainers decide for any given debug format?

It's not expected that they break - when targets do not decide on a default
format and they can handle DWARF that is automatically selected.  And
that shouldn't change whether you enable some language or not.

Richard.

>
> Thanks,
>   Jan-Benedict
>
> --