Re: Patch: RFA: operate-and-get-next fix

[Elena Zannoni <ezannoni at redhat dot com>]

Tom Tromey writes:
 > >>>>> "Elena" == Elena Zannoni <ezannoni@redhat.com> writes:
 > 
 > >> +/* This is like readline(), but it has some gdb-specific behavior.  In
 > >> +   particular, if the user is in the middle of an
 > >> +   operate-and-get-next, we shuffle the hooks around so that the
 > >> +   expected result occurs.  This is ugly, but it is inevitable given
 > >> +   that gdb switches between the two modes (async and not) of using
 > >> +   readline and that rl_pre_input_hook doesn't work properly in async
 > >> +   mode.  */
 > 
 > Elena> Ok for the other changes, but I don't understand why you are
 > Elena> setting rl_pre_input_hook in the async case, while in top.c
 > Elena> there is a comment saying the opposite:
 > 
 > The thing is, gdb uses both readline in both the synchronous and async
 > modes during a single invocation.
 > 
 > At the ordinary top-level prompt we might be using the async
 > readline.  That means we can't use rl_pre_input_hook, since it doesn't
 > work properly in async mode.
 > 
 > However, for a secondary prompt (" >", such as occurs during a
 > `define'), gdb just calls readline() directly, running it in
 > synchronous mode.
 > 
 > So for operate-and-get-next to work in this situation, we have to
 > switch the hooks around.  That is what gdb_readline_wrapper is for.
 > 

Ah, ok. 

 > I thought the comment quoted above explained the situation.
 > Apparently, though, it didn't.  Can you suggest how I should change it
 > to be more clear?  I'll make the changes and resubmit the patch.
 > 

Hey, just cut-n-paste what you wrote above. Seems pretty clear to me.

 > 
 > Long term the best fix here, in my opinion, is to fix readline so that
 > rl_pre_input_hook works properly in all situations.  That code is
 > pretty convoluted, though.  When I looked at it (must have been a year
 > ago now) it didn't look fun.
 > 

I should look to see if the new readline has improved a bit in this sense.

you can commit the changes, however, the testsuite change....is Fernando's.

thanks
Elena


 > Tom