[Gambas-devel] Problem while running gbx2/3 with gdb

[Laurent Carlier]

Le Saturday 30 August 2008 12:54:14 Benoit Minisini, vous avez écrit :
> On samedi 30 août 2008, Laurent Carlier wrote:
> > Le Saturday 30 August 2008 07:35:51 Benoit Minisini, vous avez écrit :
> > > On samedi 30 août 2008, Laurent Carlier wrote:
> > > > I was not able to run gambas 2/3 apps in gdb, as it failed on
> > > > dlopen() calls with an error while loading shared library symbols:
> > > >
> > > > ---8<---
> > > > lordh at ...607...:~/gb2projets/TunnelSDL$ gdb gbx3
> > > > GNU gdb 6.8-debian
> > > > Copyright (C) 2008 Free Software Foundation, Inc.
> > > > License GPLv3+: GNU GPL version 3 or later
> > > > <http://gnu.org/licenses/gpl.html> This is free software: you are
> > > > free to change and redistribute it. There is NO WARRANTY, to the
> > > > extent permitted by law.  Type "show copying" and "show warranty" for
> > > > details. This GDB was configured as "x86_64-linux-gnu"...
> > > > (gdb) run
> > > > Starting program: /usr/local/bin/gbx3
> > > > [Thread debugging using libthread_db enabled]
> > > > Error while reading shared library symbols:
> > > > Cannot find new threads: generic error
> > > > Cannot find new threads: generic error
> > > > (gdb) bt
> > > > #0  0x00007fe7ac19c7b7 in dl_open_worker () from
> > > > /lib64/ld-linux-x86-64.so.2 #1  0x00007fe7ac198366 in _dl_catch_error
> > > > () from /lib64/ld-linux-x86-64.so.2 #2  0x00007fe7ac19c0eb in
> > > > _dl_open () from /lib64/ld-linux-x86-64.so.2 #3  0x00007fe7abd04fbb
> > > > in dlopen_doit () from /lib/libdl.so.2
> > > > #4  0x00007fe7ac198366 in _dl_catch_error () from
> > > > /lib64/ld-linux-x86-64.so.2 #5  0x00007fe7abd0536c in _dlerror_run ()
> > > > from /lib/libdl.so.2
> > > > #6  0x00007fe7abd04f21 in dlopen@@GLIBC_2.2.5 () from /lib/libdl.so.2
> > > > #7  0x0000000000420999 in LIBRARY_load (lib=0x1eb8400) at
> > > > gbx_library.c:468 #8  0x0000000000442377 in COMPONENT_load
> > > > (comp=0x1eb83a0) at
> > > > gbx_component.c:250
> > > > #9  0x0000000000441f4e in COMPONENT_load_all () at
> > > > gbx_component.c:110 #10 0x0000000000420073 in PROJECT_load () at
> > > > gbx_project.c:456 #11 0x00000000004330aa in init (file=0x4467b8 ".")
> > > > at gbx.c:85 #12 0x000000000043366b in main (argc=1,
> > > > argv=0x7fffb43a4808) at gbx.c:299 (gdb) quit
> > > > ---8<---
> > > >
> > > > So i was not able to run gbx code inside gdb (and it's not really 
> > > > easy to do debugging without gdb !).
> > > >
> > > > Then i've filled a bug report in debian (i'm running debian sid
> > > > x86_64): http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=496494
> > > >
> > > > And ask for some help on the gdb Mailing List.
> > > >
> > > > Tonight i've succeeded to find a workaround in forcing linking of gbx
> > > > with the libpthread library.
> > > >
> > > > As far as i know, ubuntu hardy got the same problem, i would ike to
> > > > ask you if you got the same problem, and so this is a possible
> > > > workaround
> > > >
> > > > :-)
> > > >
> > > > Regards,
> > >
> > > First, you must run gbx3 with the "-p" option to prevent it from
> > > forking at startup. then, I don't see that gdb has crashed, but just
> > > breaked. So maybe you can continue the program?
> >
> > This is with and without preloading (linking with pthread)
> > --8<--
> > lordh at ...607...:~/gb2projets/TunnelSDL$ gdb gbx3
> > GNU gdb 6.8-debian
> > Copyright (C) 2008 Free Software Foundation, Inc.
> > License GPLv3+: GNU GPL version 3 or later
> > <http://gnu.org/licenses/gpl.html> This is free software: you are free to
> > change and redistribute it. There is NO WARRANTY, to the extent permitted
> > by law.  Type "show copying" and "show warranty" for details.
> > This GDB was configured as "x86_64-linux-gnu"...
> > (gdb) run
> > Starting program: /usr/local/bin/gbx3
> > [Thread debugging using libthread_db enabled]
> > [New Thread 0x7f83ea8ee6e0 (LWP 10259)]
> > [New Thread 0x421fe950 (LWP 10262)]
> > [Thread 0x421fe950 (LWP 10262) exited]
> >
> > Program exited normally.
> > (gdb) run -p
> > Starting program: /usr/local/bin/gbx3 -p
> > [Thread debugging using libthread_db enabled]
> > [New Thread 0x7f2c3161f6e0 (LWP 10263)]
> > [New Thread 0x41457950 (LWP 10264)]
> > [Thread 0x41457950 (LWP 10264) exited]
> >
> > Program exited normally.
> > (gdb)
> > --8<--
> >
> > I don't see  a lot of differences.
>
> I have committed a patch to always link gbx2 with pthread (not yet for
> gbx3). Does always linking with pthread solve the problem?

Yes, it's fixing the problem, i've applying the same patch on  G3 with the same 
success.

Regards,