[Bug ipa/109916] New: warning reported despite of "#pragma GCC diagnostic ignored", due to -flto

[Bug ipa/109916] New: warning reported despite of "#pragma GCC diagnostic ignored", due to -flto

[bruno at clisp dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109916

            Bug ID: 109916
           Summary: warning reported despite of "#pragma GCC diagnostic
                    ignored", due to -flto
           Product: gcc
           Version: 13.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bruno at clisp dot org
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

Created attachment 55127
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55127&action=edit
test case sources s.tar.xz

When adding option '-flto' to the gcc command line, diagnostics that are
ordinarily suppressed through "#pragma GCC diagnostic ignored ..." get reported
nevertheless.

How to reproduce:
1. Unpack the attached sources s.tar.xz.
$ gcc --version
gcc (GCC) 13.1.0
...
$ gcc -Wmaybe-uninitialized -O2 s/*.c -o cut
<no diagnostic>
$ gcc -Wmaybe-uninitialized -O2 s/*.c -o cut -flto
In function ‘getndelim2’,
    inlined from ‘cut_fields’ at s/cut.c:5185:17:
s/getndelim2.c:2015:23: warning: ‘c’ may be used uninitialized
[-Wmaybe-uninitialized]
 2015 |             *read_pos = c;
      |                       ^
s/getndelim2.c: In function ‘cut_fields’:
s/getndelim2.c:1934:11: note: ‘c’ was declared here
 1934 |       int c;
      |           ^

[Bug ipa/109916] warning reported despite of "#pragma GCC diagnostic ignored", due to -flto

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109916

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |amonakov at gcc dot gnu.org

--- Comment #1 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
There's a family of similar reports that "late" warnings do not observe this
pragma under LTO. I think it's best to make this a dup of the "canonical" PR.

*** This bug has been marked as a duplicate of bug 80922 ***