Re: debug/1621: Debugging with complex numbers

[Daniel Jacobowitz <drow at mvista dot com>]

On Thu, Dec 05, 2002 at 06:09:46PM -0600, Wolfgang Bangerth wrote:
> 
> 
> > >     Joseph, this report is now almost 2 years old, and versions
> > >     3.0 and 3.1/2 have happened in between. Unfortunately, there
> > >     are no testcases in the report, so I can't check the claims
> > >     myself, but do you know whether the situation has or has
> > >     not improved in the meantime?
> > 
> > The testcase is at the URL given in the report 
> > <http://gcc.gnu.org/ml/gcc/2000-12/msg00536.html>:
> 
> Oh, sorry, I seem to have overlooked this. 
> 
> 
> >         static __complex__ double x = 2.0 + 3.0i;
> >         int main(void)
> >         {
> >           return 0;
> >         }
> > 
> > (gdb) p x
> > $1 = Invalid C/C++ type code 20 in symbol table.
> > (gdb) p x$real
> > No symbol "x$real" in current context.
> > (gdb) p x$imag
> > No symbol "x$imag" in current context.
> 
> This is also the behavior I get, using 3.3CVS and gdb5.1.1. For some 
> reason, I cannot get gdb CVS compiled, so can't check whether it works 
> now. The gdb error message indicates that gcc is doing something but gdb 
> isn't understanding it.
> 
> Daniel, I'm CC:ing you since you wrote the latest mail I could find on the 
> gdb mailing lists that is about complex value support 
>   http://sources.redhat.com/ml/gdb/2002-01/msg00359.html
> 
> In this you state that you had been fixing some problems. Do you know 
> anything about gdb's present support for complex values?

GDB is fine; GCC is broken.  You'll find that in recent GCC and GDB
DWARF-2 will work fine.  Stabs will fail; the debugging output from GCC
is inconsistent.

Someone should probably fix it to use the Sun notation for such
variables (i.e. "R" instead of "r", IIRC).

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer