Re: [v4 2/2] multi-executable support (new v5 patch included)

[Pedro Alves <pedro@codesourcery.com>]

(getting back to this now)

On Tuesday 08 September 2009 20:14:07, Eli Zaretskii wrote:
> > From: Pedro Alves <pedro@codesourcery.com>
> > Date: Tue, 8 Sep 2009 16:16:16 +0100
> > Cc: Marc Khouzam <marc.khouzam@ericsson.com>,
> >  Vladimir Prus <vladimir@codesourcery.com>
> > 
> > >./gdb ./gdb
> > (top-gdb) info inferiors
> >   Num  Description       Executable
> > * 1    <null>            /home/pedro/gdb/sspaces/build/gdb/gdb
> > 
> > (top-gdb) info inferiors
> >   Num  Description       Executable
> > * 1    process 1429      /home/pedro/gdb/sspaces/build/gdb/gdb
> > 
> > (top-gdb) kill
> > Kill the program being debugged? (y or n) y
> > (top-gdb) info inferiors
> >   Num  Description       Executable
> > * 1    <null>            /home/pedro/gdb/sspaces/build/gdb/gdb
> > 
> > (top-gdb) add-inferior
> > Added inferior 2
> > 1 inferiors added.
> > 
> > (top-gdb) info inferiors
> >   Num  Description       Executable
> >   2    <null>
> > * 1    <null>            /home/pedro/gdb/sspaces/build/gdb/gdb
> > 
> > (top-gdb) inferior 2
> > [Switching to inferior 2 [process 0] (<noexec>)]
> > 
> > (top-gdb) file /home/pedro/gdb/tests/threads
> > Reading symbols from /home/pedro/gdb/tests/threads...done.
> > 
> > (top-gdb) info inferiors
> >   Num  Description       Executable
> > * 2    <null>            /home/pedro/gdb/tests/threads
> >   1    <null>            /home/pedro/gdb/sspaces/build/gdb/gdb
> > 
> > (top-gdb) start
> > Temporary breakpoint 4 at 0x400640: file threads.c, line 35.
> > Starting program: /home/pedro/gdb/tests/threads
> > [Thread debugging using libthread_db enabled]
> > 
> > Temporary breakpoint 4, main () at threads.c:35
> > 35          long i = 0;
> > (top-gdb) info inferiors
> >   Num  Description       Executable
> > * 2    process 1526      /home/pedro/gdb/tests/threads
> >   1    <null>            /home/pedro/gdb/sspaces/build/gdb/gdb
> 
> This is what I had in mind, yes.  If it really works in practice (and
> others are happy with this model), then great.

I still don't know for certain exactly what to do with the DICOS
model here, but, I can certainly see the value of the simplicity
of this model by default.  This is also the model that allows
mapping HPD ptsets (or itsets on the multi-process branch) cleanly
to GDB.

> 
> > The symbol-spaces concept is still needed and is still there, but
> > the user doesn't see them anymore.  I've moved "info symbol-spaces"
> > to "maintenanced info symbol-spaces".
> 
> Maybe rename that to "maintenance info program-spaces".  It's quite
> easy to explain that a ``program space'' is a space in which to run
> programs.

I like this.  I've renamed symbol spaces to program spaces
throughout the patch as well.

> 
> >  (gdb) attach 123
> >  Attached to process 123.
> >  (gdb) info inferiors
> >   Num  Description       Executable
> >   1    <null>            
> > * 2    Process 2323
> > 
> > It's a shame, and that was one of my main concerns (that we'd
> > end up getting too stuck in the unix model of things) but I guess
> > we can live with it somehow.
> 
> Can't we have that inferior hidden in "info inferiors", like we do
> with breakpoints set by GDB for its own purposes?

I'm not sure about this.  I think I'll leave it as is for now,
and return to it at some point after the main patch is in.  It's been
a bit frustrating to keep the patch up to date to mainline, as new
regressions keep popping up, simply due to the fact that new code
isn't considering multi-exec/process.  I'd like to be able to do
incremental development on top.

I'll post a new patch in a bit.

-- 
Pedro Alves