[Bug c++/115624] New: '-Wnrvo' is not an option that controls warnings

[Bug c++/115624] New: '-Wnrvo' is not an option that controls warnings

[albrecht.guendel at web dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115624

            Bug ID: 115624
           Summary: '-Wnrvo' is not an option that controls warnings
           Product: gcc
           Version: 14.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: albrecht.guendel at web dot de
  Target Milestone: ---

Hi, 
the new -Wnrvo warning is an amazing diagnostic.
However it does not play well with the #pragma GCC diagnostic directive. Yet.

Test-Case: https://godbolt.org/z/Tq8e8zPx8  

For the sake of completeness, here is the code:

using GCC 14.1 with "-Wnrvo" option

#include <string>
#pragma GCC diagnostic ignored "-Wnrvo"

std::string no_nrvo(int i)
{
    std::string ret{};
    if (i % 2)
        return {};
    return ret;
}


Current behavior:
warning: '-Wnrvo' is not an option that controls warnings [-Wpragmas]
warning: not eliding copy on return in 'std::string no_nrvo(int)' [-Wnrvo]

Expected behavior:
accept the "#pragma GCC diagnostic ignored" and do not diagnose the missed
optimization.

[Bug c++/115624] '-Wnrvo' is not an option that controls warnings

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115624

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org
     Ever confirmed|0                           |1
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=58487
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2024-06-25

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I know the obvious patch which should fix this.

[Bug c++/115624] '-Wnrvo' is not an option that controls warnings

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115624

--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:f7747210947a7c66e865c6ac571cce39e2b87caf

commit r15-1590-gf7747210947a7c66e865c6ac571cce39e2b87caf
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Mon Jun 24 18:16:13 2024 -0700

    c-family: Add Warning property to Wnrvo option [PR115624]

    This was missing when Wnrvo was added in
    r14-1594-g2ae5384d457b9c67586de012816dfc71a6943164 .

    Pushed after a bootstrap/test on x86_64-linux-gnu.

    gcc/c-family/ChangeLog:

            PR c++/115624
            * c.opt (Wnrvo): Add Warning property.

    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

[Bug c++/115624] '-Wnrvo' is not an option that controls warnings

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115624

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-14 branch has been updated by Andrew Pinski
<pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:b7157f3930762097210aa24a3f24ed5cafee6672

commit r14-10344-gb7157f3930762097210aa24a3f24ed5cafee6672
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Mon Jun 24 18:16:13 2024 -0700

    c-family: Add Warning property to Wnrvo option [PR115624]

    This was missing when Wnrvo was added in
    r14-1594-g2ae5384d457b9c67586de012816dfc71a6943164 .

    Pushed after a bootstrap/test on x86_64-linux-gnu.

    gcc/c-family/ChangeLog:

            PR c++/115624
            * c.opt (Wnrvo): Add Warning property.

    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
    (cherry picked from commit f7747210947a7c66e865c6ac571cce39e2b87caf)

[Bug c++/115624] '-Wnrvo' is not an option that controls warnings

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115624

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.2
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed.