Re: [PATCH] ctf: Do not warn for CTF not supported for GNU GIMPLE

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

On Wed, Sep 29, 2021 at 5:55 PM Indu Bhagat <indu.bhagat@oracle.com> wrote:
>
> On 9/29/21 12:14 AM, Richard Biener wrote:
> > On Tue, Sep 28, 2021 at 8:52 PM Indu Bhagat via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> >>
> >> CTF is supported for C only.  Currently, a warning is emitted if the -gctf
> >> command line option is specified for a non-C frontend.  This warning is also
> >> used by the GCC testsuite framework - it skips adding -gctf to the list of
> >> debug flags for automated testing, if CTF is not supported for the frontend.
> >>
> >> The following warning, however, is not useful in case of LTO:
> >>
> >> "lto1: note: CTF debug info requested, but not supported for ‘GNU GIMPLE’
> >> frontend"
> >>
> >> This patch disables the generation of the above warning for GNU GIMPLE.
> >>
> >> Bootstrapped and regression tested on x86_64.
> >>
> >> gcc/ChangeLog:
> >>
> >>          * toplev.c (process_options): Do not warn for GNU GIMPLE.
> >> ---
> >>   gcc/toplev.c | 12 +++++++-----
> >>   1 file changed, 7 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/gcc/toplev.c b/gcc/toplev.c
> >> index e1688aa..511a343 100644
> >> --- a/gcc/toplev.c
> >> +++ b/gcc/toplev.c
> >> @@ -1416,14 +1416,16 @@ process_options (void)
> >>          debug_info_level = DINFO_LEVEL_NONE;
> >>       }
> >>
> >> -  /* CTF is supported for only C at this time.
> >> -     Compiling with -flto results in frontend language of GNU GIMPLE.  */
> >> +  /* CTF is supported for only C at this time.  */
> >>     if (!lang_GNU_C ()
> >>         && ctf_debug_info_level > CTFINFO_LEVEL_NONE)
> >>       {
> >> -      inform (UNKNOWN_LOCATION,
> >> -             "CTF debug info requested, but not supported for %qs frontend",
> >> -             language_string);
> >> +      /* Compiling with -flto results in frontend language of GNU GIMPLE.  It
> >> +        is not useful to warn in that case.  */
> >> +      if (!startswith (lang_hooks.name, "GNU GIMPLE"))
> >
> > please use in_lto_p instead
> >
> > OK with that change.
> >
>
> in_lto_p is set later in lto_init () (when its time for do_compile ()).
>
> in_lto_p's updated value is not available at this point in
> process_options ().

I see - a bit ugly IMHO but I guess the patch is OK then.

Thanks,
Richard.

> >> +       inform (UNKNOWN_LOCATION,
> >> +               "CTF debug info requested, but not supported for %qs frontend",
> >> +               language_string);
> >>         ctf_debug_info_level = CTFINFO_LEVEL_NONE;
> >>       }
> >>
> >> --
> >> 1.8.3.1
> >>
>