Re: gdb 5.0: no symbol 'foo' in current context

[Daniel Berlin]

address@hidden (Thomas Sevaldrud) writes:

I *believe* this was a known bug in the compiler, it should be fixed
in the latest compiler errata, make sure you have the latest gcc
update for redhat 7.
--Dan
> Hello,
> 
> I am having a problem with debugging c++ programs with gdb 5.0. I am running 
> on
> a RedHat 7.0 system, and the bug may of course be related to the non-standard
> compiler shipping with this system. However, I hope someone on this list might
> have heard about this problem, and hopefully know of a fix or workaround to 
> it.
> 
> The problem is that the debugger doesn't find the contents of variables that
> are inside nested scopes. For example, in the following program gdb won't 
> print
> the contents of either variables 'b' or 'c'
> 
>  int main(int argc, char** argv)
>  {
>   int a = 10;
>   for(int i = 0; i < 10; i++)
>      {
>      for(int j = 0; j < 10; j++)
>         {
>         int b = 20;
>         int c = 30;
>         }
>      }
>  }
> 
> I compile this program with
> 
>  address@hidden [tse] 109> g++ -g -o foo foo.cpp
> 
> Then I run the debugger:
> 
>  address@hidden [tse] 110> gdb foo
>  GNU gdb 5.0
>  Copyright 2000 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) break main
>  Breakpoint 1 at 0x8048532: file foo.cpp, line 3.
>  (gdb) run
>  Starting program: /home/tse/foo 
> 
>  Breakpoint 1, main (argc=1, argv=0xbffff0e4) at foo.cpp:3
>  3     int a = 10;
>  (gdb) next
>  4     for(int i = 0; i < 10; i++)
>  (gdb) print a
>  $1 = 10
>  (gdb) next 3
>  9           int c = 30;
>  (gdb) print b
>  No symbol "b" in current context.
>  (gdb) 
> 
> Here is some more info on my system:
> 
>  address@hidden [tse] 112> uname -a
>  Linux sauron.si.sintef.no 2.2.16-22smp #1 SMP Tue Aug 22 16:39:21 EDT 2000 
> i686 unknown
> 
>  address@hidden [tse] 113> g++ --version
>  2.96
> 
> 
> If a variable is declared between the scopes here, such as in the following
> code, all variables are found without problems. 
> 
>  int main(int argc, char** argv)
>  {
>   int a = 10;
>   for(int i = 0; i < 10; i++)
>      {
>      int b = 20;
>      for(int j = 0; j < 10; j++)
>         {
>         int c = 30;
>         }
>      }
>  }
> 
> 
> I am not subscribed to the mailing list, so please CC the answer to my email
> address.
> 
> 
> Regards,
> Thomas Sevaldrud