Re: gdb does not print the reference to the base class members

["Douglas Evans" <dje@google.com>]

Hi.  The bug is in gcc, not gdb, so no change in gdb version is going
to fix this.  See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27574
for details of the bug.

On Nov 20, 2007 8:55 PM, Peng Yu <pengyu.ut@gmail.com> wrote:
> Hi,
>
> This is the version that I'm using. Will the problem be solved if I
> upgrade to the latest version, GDB version 6.7.1?
>
> Thanks,
> Peng
>
> $ gdb --version
> GNU gdb 6.6-debian
> Copyright (C) 2006 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-linux".
>
>
>
> On Nov 19, 2007 2:39 AM, Douglas Evans <dje@google.com> wrote:
> > I  believe this is gcc bug 27574.
> >
> >
> > On Nov 18, 2007 4:35 PM, Peng Yu <pengyu.ut@gmail.com> wrote:
> > > Hi,
> > >
> > > I try to print reference x for the following problem. But gdb does not
> > > print the one in class B refered to class A? Do you know how to print
> > > its value?
> > >
> > > Thanks,
> > > Peng
> > >
> > > (gdb) b 22
> > > Breakpoint 1 at 0x8048694: file main.cc, line 22.
> > > (gdb) b 14
> > > Breakpoint 2 at 0x8048706: file main.cc, line 14.
> > > (gdb) r
> > > Failed to read a valid object file image from memory.
> > >
> > > Breakpoint 1, main () at main.cc:22
> > > 22        B b(10);
> > > (gdb) p x
> > > $1 = (int &) @0xbffd86cc: 5
> > > (gdb) c
> > >
> > > Breakpoint 2, B (this=0xbffd86c8, a=10) at main.cc:14
> > > 14            std::cout << x << std::endl;
> > > (gdb) p x
> > > No symbol "x" in current context.
> > >
> > >
> > >
> > > #include <iostream>
> > >
> > > class A {
> > >   public:
> > >     A(int a) : _a(a) { }
> > >   protected:
> > >     int _a;
> > > };
> > >
> > > class B : public A {
> > >   public:
> > >     B(int a) : A(a) {
> > >       int &x = A::_a;//can not print from gdb, Line 12
> > >       std::cout << x << std::endl;
> > >     }
> > > };
> > >
> > >
> > > int main(){
> > >   int a = 5;
> > >   int &x = a;//this one can be printed in gdb, Line 22
> > >   B b(10);
> > >   std::cout << x << std::endl;
> > > }
> > >
> >
>