[Bug rtl-optimization/10837] noreturn attribute causes no sibling calling optimization

["xry111 at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10837

Xi Ruoyao <xry111 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=83324
                 CC|                            |xry111 at gcc dot gnu.org

--- Comment #16 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to gooncreeper from comment #15)
> May I suggest we just add something like __attribute__((trace)) for the
> special abort case? Noreturn was added for code optimization after all, not
> for backtracing.

It will break any attempts to debug an abort until the libc headers are updated
to use __attribute__((trace)).

Note that in GCC noreturn has been added far before the WG14 _Noreturn paper
(even this ticket predates the WG14 paper), so the rationale in the paper may
not apply.

In practice most _Noreturn functions are abort, exit, ..., i.e. they are only
executed one time so optimizing against a cold path does not help much.  I
don't think it's a good idea to encourage people to construct some fancy code
by a recursive _Noreturn function (why not just use a loop?!)  And if you must
write such fancy code anyway IMO musttail attribute (PR83324) will be a better
solution.