Re: [PATCH] Readline: Cleanup some warnings

[Eli Zaretskii <eliz@gnu.org>]

> Cc: tom@tromey.com, gdb-patches@sourceware.org
> From: Pedro Alves <palves@redhat.com>
> Date: Thu, 21 Mar 2019 17:31:07 +0000
> 
> So that means that the readline hack in mingw-hdep.c:
> 
>   /* With multi-threaded SIGINT handling, there is a race between the
>      readline signal handler and GDB.  It may still be in
>      rl_prep_terminal in another thread.  Do not return until it is
>      done; we can check the state here because we never longjmp from
>      signal handlers on Windows.  */
>   while (RL_ISSTATE (RL_STATE_SIGHANDLER))
>     Sleep (1);
> 
> with new-enough readline, is no longer doing anything, since the while
> loop's condition is always false.
> 
> However, there's another question that needs answering: what are we going to
> do if even after upgrading our readline version, someone builds gdb against
> the system readline, and the system readline happens to be an older version
> that still depends on this or some other readline hack?  We'll silently
> regress.  I think that we need to document the minimum readline version
> somewhere (gdb/README?), and have something (configure?) enforce it.
> (There's a RL_READLINE_VERSION symbol.)

SGTM, thanks for digging into this.