[Bug rust/108087] New: -Wodr warnings in rust/rust-lang.cc (lang_type)

[Bug rust/108087] New: -Wodr warnings in rust/rust-lang.cc (lang_type)

[sam at gentoo dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108087

            Bug ID: 108087
           Summary: -Wodr warnings in rust/rust-lang.cc (lang_type)
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rust
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sam at gentoo dot org
                CC: dkm at gcc dot gnu.org, gcc-rust at gcc dot gnu.org
  Target Milestone: ---

Created attachment 54082
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54082&action=edit
build.log.xz (slightly past warning)

Noticed when bootstrapping GCC 13 from trunk at r13-4681-g531ca06c007d4c.
```
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/rust-lang.cc:67:17:
warning: type [-Wodr]
   67 | struct GTY (()) lang_type
      |                 ^
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/backend/rust-tree.h:234:
note: a different type is defined in another translation unit
  234 | struct GTY (()) lang_type
      |
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/backend/rust-tree.h:236:
note: the first difference of corresponding definitions is field ‘align’
  236 |   unsigned char align;
      |
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/backend/rust-tree.h:234:
note: a type with different number of fields is defined in another translation
unit
  234 | struct GTY (()) lang_type
      |
```

I've attached the build.log compressed a bit past the point of the warning, as
it's still building.

Host compiler is 12.2.1_p20221210.

[Bug rust/108087] -Wodr warnings in rust/rust-lang.cc (lang_type)

[sam at gentoo dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108087

--- Comment #1 from Sam James <sam at gentoo dot org> ---
Sorry, output got mangled slightly by ansifiltering:
```
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/rust-lang.cc:67:17:
warning: type ‘struct lang_type’ violates the C++ One Definition Rule [-Wodr]
   67 | struct GTY (()) lang_type
      |                 ^
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/backend/rust-tree.h:234:
note: a different type is defined in another translation unit
  234 | struct GTY (()) lang_type
      |
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/backend/rust-tree.h:236:
note: the first difference of corresponding definitions is field ‘align’
  236 |   unsigned char align;
      |
/var/tmp/portage/sys-devel/gcc-13.0.9999/work/gcc-13.0.9999/gcc/rust/backend/rust-tree.h:234:
note: a type with different number of fields is defined in another translation
unit
  234 | struct GTY (()) lang_type
      |
```

[Bug rust/108087] -Wodr warnings in rust/rust-lang.cc (lang_type)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108087

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |build

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This does look like a real issue in the rust front-end.
lang_type is defined differently in those two files.

[Bug rust/108087] -Wodr warnings in rust/rust-lang.cc (lang_type)

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108087

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
                 CC|                            |marxin at gcc dot gnu.org
   Last reconfirmed|                            |2022-12-14
     Ever confirmed|0                           |1

--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
Yes, I think it's a real issue.

[Bug rust/108087] -Wodr warnings in rust/rust-lang.cc (lang_type)

[arthur.cohen at embecosm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108087

Arthur Cohen <arthur.cohen at embecosm dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |arthur.cohen at embecosm dot com

--- Comment #4 from Arthur Cohen <arthur.cohen at embecosm dot com> ---
Thanks everyone, this is indeed a real issue and a mishap on our part. It's due
to our const evaluator, which was ported over from the C++ frontend, defining
another lang_type struct similar to what is the C++ one. I'm working on fixing
it. I've opened up https://github.com/Rust-GCC/gccrs/issues/1702 and will
report progress

[Bug rust/108087] -Wodr warnings in rust/rust-lang.cc (lang_type)

[cohenarthur at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108087

Arthur Cohen <cohenarthur at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED