Re: Help: cannot break into shared libraries on LinuxPPC

[Kevin Buettner <kevinb at redhat dot com>]

On Jan 29, 12:15am, yuming5@attbi.com wrote:

> I have a problem that the gdb cannot break into the shared library -- actually, 
> it successfully breaks into the very first function defined in the shared 
> library source file(i.e. libPrint() in printlib.c, see the following example), 
> but failed to break into the other functions in that same source file (i.e. 
> libErrPrint() in printlib.c).
> 
> This was run with Linux2.2.17 on PowerPC. Other information:
> gcc version 2.95.3, GNU ld and ar version 2.10.91.
> 
> Please see below the gdb output and the shell script used to create the 
> executable and shared library.
> 
> Any idea what went wrong?
[...]
> The gdb output:
> it didn't break into libErrPrint().
> ------------------------------------------------------------------
> ... ...
> Breakpoint 1, libPrint (a=3) at printlib.c:9
> 9           b = a;
> (gdb) n 
> 10          printf(">>>libPrint, %d\n",b);
> (gdb) 
> >>>libPrint, 3
> 11      }
> (gdb) 
> main () at main.c:13
> 13              libErrPrint(3);
> (gdb) step
> 0x30025fc4 in .LC0 () from /lib/ld.so.1
> (gdb) n
> Single stepping until exit from function .LC0, 
> which has no line number information.
> 
> Breakpoint 2, 0x0ffdf4ac in libErrPrint (a=268367100) 
> from /home/mark/test/sharedlib/libmp_shr.so

I'm not sure what's going on.

You've hit the breakpoint in libErrPrint(), but there's no line number
information associated with it.  I'm don't how this can be since (you
say) libPrint() and libErrPrint() are in the same source file and
libPrint() clearly does have line number information associated with
it.

Try using objdump to look at the contents of the object files and
libraries to make sure that they contain everything they should.

Kevin