Re: c++/1069: Issues printing derived objects with gdb

[Daniel Jacobowitz <drow at mvista dot com>]

The following reply was made to PR c++/1069; it has been noted by GNATS.

From: Daniel Jacobowitz <drow at mvista dot com>
To: monte at juniper dot net
Cc: gdb-gnats at sources dot redhat dot com
Subject: Re: c++/1069: Issues printing derived objects with gdb
Date: Wed, 19 Feb 2003 11:34:52 -0500

 On Wed, Feb 19, 2003 at 04:19:56PM -0000, monte at juniper dot net wrote:
 > 
 > >Number:         1069
 > >Category:       c++
 > >Synopsis:       Issues printing derived objects with gdb
 > >Confidential:   no
 > >Severity:       serious
 > >Priority:       medium
 > >Responsible:    unassigned
 > >State:          open
 > >Class:          change-request
 > >Submitter-Id:   net
 > >Arrival-Date:   Wed Feb 19 16:28:00 UTC 2003
 > >Closed-Date:
 > >Last-Modified:
 > >Originator:     Monte Becker
 > >Release:        GDB 5.3,  GCC 2.95.3
 > >Organization:
 > >Environment:
 > (gdb) show version
 > GNU gdb 5.3
 > Copyright 2002 Free Software Foundation, Inc.
 > GDB is free software, covered by the GNU General Public License, and you are
 > welcome to change it and/or distribute copies of it under certain conditions.
 > Type "show copying" to see the conditions.
 > There is absolutely no warranty for GDB.  Type "show warranty" for details.
 > This GDB was configured as "sparc-sun-solaris2.8".
 > 
 > monte-cristo > gcc -v
 > Reading specs from /usr/local/lib/gcc-lib/sparc-sun-solaris2.8/2.95.3/specs
 > gcc version 2.95.3 20010315 (release)
 > >Description:
 > Try as I might, I can't look at the contents of a derived 
 > object.  The object in question has some static members.
 > For example:  
 > 
 > ...AHHHH... 
 > 
 > It worked the second time.  OK, here's the first time:
 > 
 > (gdb) p RV0_3
 > $1 = {<random_variable> = {static m_default_seed = Internal: global symbol `_15random_variable.m_default_seed' found in /net/cristo/ldisk/work/monte/sand/tga_top/tga/cv_verif/c_shared_tb/random_variable.C psymtab but not in symtab.
 > _15random_variable.m_default_seed may be an inlined function, or may be a template function
 > (if a template, try specifying an instantiation: _15random_variable.m_default_seed<type>).
 > 
 > And here's the second time:
 > 
 > (gdb) whatis RV0_3
 > type = uniform_rv
 > (gdb) p RV0_3
 > $2 = {<random_variable> = {static m_default_seed = 0x6, 
 >     _vptr. = 0x61a50 <uniform_rv virtual table>}, m_min = 0x0, m_max = 0x3, 
 >   mt = {0x995147ee, 0xddfb0c04, 0x8fbe12, 0xd9e031f0, 0xc140f856, 0x6b1316dc, 
 > ....(The stuff I would expect)
 
 I've seen this one before.  I think we know where it comes from now...
 
 > Then I tried to print the result of a method:
 > 
 > (gdb) p RV0_3.gen()
 > 
 > Breakpoint 2, filebuf::filebuf ()
 >     at /net/cristo/ldisk/work/monte/sand/tga_top/tga/cv_verif/c_dram_tb/TgaDRamTest_Rand.C:105
 > The program being debugged stopped while in a function called from GDB.
 > When the function (uniform_rv::gen(void)) is done executing, GDB will silently
 > stop (instead of continuing to evaluate the expression containing
 > the function call).
 > 
 > There are no breaks inside of this object.
 
 Are you sure?  Do you have a break at filebuf::filebuf, and what's the
 backtrace look like when GDB claims you've hit it?
 
 > >How-To-Repeat:
 > 
 > (Will construct test case if needed.  Let me know.)
 
 It always helps if you can do this.
 
 -- 
 Daniel Jacobowitz
 MontaVista Software                         Debian GNU/Linux Developer