Re: casting in gdb

[Daniel Jacobowitz <drow at mvista dot com>]

On Sat, Dec 14, 2002 at 10:49:46PM -0500, Jacques Le Normand wrote:
> 
> 
> 
>  That explains alot, thanks
>  Would you know how to tell g++ to keep all the methods, even when they're
>  not used?

You can't; you've gotta add a dummy function which uses them, or
explicitly instantiate them.

>  Say I have a map<string,int> m, how would I get gdb to display m["foo"] ?
> It
>  gives me the silly "function expects something else" error, which I can
>  understand since gdb won't cast from char* to string. I'm guessing I need
> to
>  define my own subroutines.

Pretty much.  Some day you GDB may do this for you but it doesn't right
now.

>  --Jacques
> > ----- Original Message -----
> > From: "Daniel Jacobowitz" <drow@mvista.com>
> > To: "Jacques Le Normand" <jacqueslen@sympatico.ca>
> > Cc: "Daniel Berlin" <dberlin@dberlin.org>; <gdb@sources.redhat.com>
> > Sent: Saturday, December 14, 2002 2:35 AM
> > Subject: Re: casting in gdb
> >
> >
> > > On Fri, Dec 13, 2002 at 02:43:17PM -0500, Jacques Le Normand wrote:
> > > > here you go, thanks for lending a hand...
> > > >
> > > > [countchocula@chocoland countchocula]$ g++ -ggdb test.cpp -o test.o
> > > > [countchocula@chocoland countchocula]$ gdb test.o
> > > > GNU gdb Red Hat Linux (5.2.1-4)
> > > > 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 "i386-redhat-linux"...
> > > > (gdb) b 10
> > > > Breakpoint 1 at 0x80486f5: file test.cpp, line 10.
> > > > (gdb) r
> > > > Starting program: /home/countchocula/test.o
> > > >
> > > > Breakpoint 1, main () at test.cpp:10
> > > > 10        a.push_back(2);
> > > > (gdb) p a[0]
> > > > One of the arguments you tried to pass to operator[] could not be
> > converted
> > > > to w
> > > > hat the function wants.
> > > > (gdb)
> > >
> > > This one's pretty simple once you figure it out.  The error message is
> > > really bad; I'll hold on to this and try to improve it.
> > >
> > > Your program doesn't _use_ operator[].  So it doesn't get compiled into
> > > the program, and GDB can't call it to figure out what to do.
> > >
> > > What happens if you add a call to the operator?
> > >
> > > [I noticed some other quirks; for instance, if your program only uses
> > > the mutable version and GDB finds the const version first, it may get
> > > confused...]
> > >
> > > --
> > > Daniel Jacobowitz
> > > MontaVista Software                         Debian GNU/Linux Developer
> > >
> >
> 
> 

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer