[Bug c++/107496] New: [Feature request] Conditional attributes

[Bug c++/107496] New: [Feature request] Conditional attributes

[jwjagersma at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107496

            Bug ID: 107496
           Summary: [Feature request] Conditional attributes
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jwjagersma at gmail dot com
  Target Milestone: ---

I'd like to request a new extension feature: the ability to enable or disable
attributes based on a conditional expression.

This could be implemented either via a sort of meta-attribute:

    template <bool A, bool B>
    [[gnu::conditional(A, always_inline), gnu::conditional(B, noinline)]]
    auto f() { /* ... */ }

Or by reusing the template syntax:

    template <bool A, bool B>
    [[gnu::always_inline<A>, gnu::noinline<B>]]
    auto f() { /* ... */ }

Although maybe the latter should only be allowed via the __attribute__ syntax,
which is already a GNU extension.

I did recently send in a small patch to allow selecting a string conditionally
in the i386 'target' attribute (no responses yet though).  I really need it for
that particular case, and it would be nice if that could make it in gcc 13, if
there are no objections.

For the longer term though, I think being able to apply this to all attributes
would be a very useful feature to have.

[Bug c++/107496] [Feature request] Conditional attributes

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107496

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement