[Bug c++/67991] New: Pointer to function with internal linkage not being allowed, when it should be

[Bug c++/67991] New: Pointer to function with internal linkage not being allowed, when it should be

[nacitar at ubercpp dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

            Bug ID: 67991
           Summary: Pointer to function with internal linkage not being
                    allowed, when it should be
           Product: gcc
           Version: 5.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nacitar at ubercpp dot com
  Target Milestone: ---

Created attachment 36528
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36528&action=edit
test driver

Returning a function pointer from a constexpr function is leading to an error,
in a context where using the function pointer directly does in fact work.  I
don't see why it should be different.

I already asked the isocpp group about this:

https://groups.google.com/a/isocpp.org/forum/embed/?place=forum/std-discussion&showsearch=true&showpopout=true&parenturl=https://isocpp.org/forums/iso-c-standard-discussion#!topic/std-discussion/OKfPmu95en4

They stated: "This is a GCC bug. Pointers to functions with internal linkage
are fine since C++11."

[Bug c++/67991] Pointer to function with internal linkage not being allowed, when it should be

[nacitar at ubercpp dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

--- Comment #1 from Jacob McIntosh <nacitar at ubercpp dot com> ---
http://open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4268.html

This is the relevant standard change (as mentioned in the isocpp thread i
linked)

[Bug c++/67991] Pointer to function with internal linkage not being allowed, when it should be

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Are you sure this is not C++14 feature.

[Bug c++/67991] Pointer to function with internal linkage not being allowed, when it should be

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Try -std=c++1y or -std=c++1z .

[Bug c++/67991] Pointer to function with internal linkage not being allowed, when it should be

[nacitar at ubercpp dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

--- Comment #4 from Jacob McIntosh <nacitar at ubercpp dot com> ---
It looks like this is supposed to be a c++1y/1z feature (post c++-14 anyway)...
and it looks like it's not implemented yet in gcc.  Same errors for me with
-std=c++1y and also with -std=c++1z

[Bug c++/67991] Pointer to function with internal linkage not being allowed, when it should be

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jacob McIntosh from comment #4)
> It looks like this is supposed to be a c++1y/1z feature (post c++-14
> anyway)... and it looks like it's not implemented yet in gcc.  Same errors
> for me with -std=c++1y and also with -std=c++1z

Have you tried the trunk instead?

[Bug c++/67991] Pointer to function with internal linkage not being allowed, when it should be

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed on the trunk with -std=c++17 .  Since this is a new feature of C++17,
it is not as important as other bugs in the C++ front-end at this stage.