Re: pending breakpoints change breakpoint number

[Andrew Cagney <cagney@gnu.org>]

> Hi, all...
> 
> I have been looking at the pending breakpoint changes (to merge them into the Apple gdb).  Overall it is nicer than the future-break version that we had, so that is great.
> 
> However, one thing really bugs me about it.  That is that it changes the breakpoint number out from under me when it manages to resolve the breakpoint.
> 
> This is pretty annoying to a human user, since if I want to do anything to the breakpoint, I have to go find it's number again from info break.  But it is very bad for a gui that is trying to run gdb from, say, the MI.  The GUI has to use the breakpoint number to do things like disable the breakpoint, delete it, etc.  So if the number switches out from under it, the gui can no longer operate on the breakpoint.  Very bad...
> 
> So there are two things that need to be addressed here.
> 
> First off, if we are going to change the breakpoint number, clearly need a breakpoint_resolved event/hook/observer thingie that we can use to tell the GUI that breakpoint 2 resolved to breakpoint 5, and the GUI needs to change accordingly.  This is pretty easy.  If it were a gdb_event, the addition to gdb-events.sh would look like:

The breakpoint number changing is a known bug in the current 
implementation.  It was concluded that fixing it (a non-trivial task) 
was closely tied to fixing things like M:N breakpoints (one breakpoint 
with multiple locations) and hence should be made part of that task 
(painful but working pending breakpoints were considered better than no 
pending breakpoints).

Seems that the N:M breakpoints have fallen by the wayside.  Interested 
in working on that?  Daniel can give you a status report of where things 
are at.

Andrew