From mboxrd@z Thu Jan  1 00:00:00 1970
From: Holger Kiehl <Holger.Kiehl@dwd.de>
Subject: Question about core files
Date: Tue, 6 Oct 2009 14:04:14 +0000 (GMT)
Message-ID: <Pine.LNX.4.64.0910061349060.9660@praktifix.dwd.de>
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Hello

Most the time I compile my application without the -g option due to
performance reasons. Problem is that when it hits some bug and dumps
core, this is not very useful because there is hardly any information
in it. Is there some way to get some useful information out of
the core file. For example one of my program crashed and with gdb
I see the following:

    afd@helena:~$ gdb fd core.2515
    GNU gdb Fedora (6.8-24.fc9)
    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-redhat-linux-gnu"...
    (no debugging symbols found)

    warning: Can't read pathname for load map: Input/output error.
    Reading symbols from /lib64/libc-2.8.so...Reading symbols from /usr/lib/debug/lib64/libc-2.8.so.debug...done.
    done.
    Loaded symbols for /lib64/libc-2.8.so
    Reading symbols from /lib64/ld-2.8.so...Reading symbols from /usr/lib/debug/lib64/ld-2.8.so.debug...done.
    done.
    Loaded symbols for /lib64/ld-2.8.so
    Reading symbols from /lib64/libnss_files-2.8.so...Reading symbols from /usr/lib/debug/lib64/libnss_files-2.8.so.debug...done.
    done.
    Loaded symbols for /lib64/libnss_files-2.8.so
    Core was generated by `fd -w /home/afd'.
    Program terminated with signal 6, Aborted.
    [New process 2515]
    #0  0x000000304cc32215 in raise (sig=<value optimized out>)
        at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
    64        return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
    (gdb) where
    #0  0x000000304cc32215 in raise (sig=<value optimized out>)
        at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
    #1  0x000000304cc33d83 in abort () at abort.c:88
    #2  0x000000000040b174 in sig_segv ()
    #3  <signal handler called>
    #4  0x0000000000404b5f in start_process ()
    #5  0x0000000000407b9a in main ()

At least I know that the bug is in my function start_process. But is
there some way to find out at what line it happened?

Thanks,
Holger