[Bug c++/81159] New warning idea: -Wself-move

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81159

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:0abb78dda084a14b3d955757c6431fff71c263f3

commit r13-2227-g0abb78dda084a14b3d955757c6431fff71c263f3
Author: Marek Polacek <polacek@redhat.com>
Date:   Mon Aug 8 17:45:28 2022 -0400

    c++: Implement -Wself-move warning [PR81159]

    About 5 years ago we got a request to implement -Wself-move, which
    warns about useless moves like this:

      int x;
      x = std::move (x);

    This patch implements that warning.

            PR c++/81159

    gcc/c-family/ChangeLog:

            * c.opt (Wself-move): New option.

    gcc/cp/ChangeLog:

            * typeck.cc (maybe_warn_self_move): New.
            (cp_build_modify_expr): Call maybe_warn_self_move.

    gcc/ChangeLog:

            * doc/invoke.texi: Document -Wself-move.

    gcc/testsuite/ChangeLog:

            * g++.dg/warn/Wself-move1.C: New test.