[Bug c++/81973] alias virtual function does not cause the vtable to be emitted even if the aliased function is defined in the TU

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81973

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |link-failure
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-12-22
             Status|UNCONFIRMED                 |NEW
            Summary|Aliased virtual methods are |alias virtual function does
                   |treated as undefined, so    |not cause the vtable to be
                   |the vtable is not generated |emitted even if the aliased
                   |                            |function is defined in the
                   |                            |TU

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

Note GCC (since 8) does warn about the types being different now:
<source>:14:22: warning: 'void s::g()' alias between functions of incompatible
types 'void (s::)()' and 'void(s*)' [-Wattribute-alias=]
   14 |                 void g() __attribute__ ((alias ("s_g_alias")));
      |                      ^
<source>:25:14: note: aliased declaration here
   25 |         void s_g_alias(s* this_){
      |              ^~~~~~~~~