X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f
X-Recipient: djgpp AT delorie DOT com
X-Authenticated: #27081556
X-Provags-ID: V01U2FsdGVkX1/hCBJDhJDhmGw7Aie9tJXz9D/l+suSEcKRAVg2rA
	kHkMhP69sjGvrR
Message-ID: <51B36263.6080309@gmx.de>
Date: Sat, 08 Jun 2013 18:57:07 +0200
From: Juan Manuel Guerrero <juan DOT guerrero AT gmx DOT de>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121025 Thunderbird/16.0.2
MIME-Version: 1.0
To: djgpp AT delorie DOT com
Subject: Programs compiled with gcc481 cannot be debugged with gdb.
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 7bit
X-Y-GMX-Trusted: 0
Reply-To: djgpp AT delorie DOT com

Please inspect the small program below:

#include <stdio.h>

void f(const int i)
{
   printf("a=%d\n", i);
}

int main(void)
{
   int a = 1;
   f(a);
   return a;
}


I have compiled it using gcc-4.8.1 with the following command:
   gcc -Wall -g2 -O0 a.c
When I try to use gdb to step through the code I get
the following error message:

GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=i786-pc-msdosdjgpp --target=djgpp".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from c:/tmp/a.exe...done.
(gdb) b main
Breakpoint 1 at 0x1eba: file 1.c, line 10.
(gdb) r
Starting program: c:/tmp/a.exe

Breakpoint 1, main () at 1.c:10
10        int a = 1;
(gdb) s
11        f(a);
(gdb)
f (i=<error reading variable: can't compute CFA for this frame>) at 1.c:5
5         printf("a=%d\n", i);
(gdb) p i
can't compute CFA for this frame
(gdb)


The important issue is to try to step into a function.
As long as I do not step into a function every thing works OK.
The same happens if I use gcc480.  If I use gcc473 every thing
works OK.  The program itself runs flawlessly.
Am I missing something?  Is the coff/dwarf support in gcc-4.8.N
brocken?

If more info is needed, please tell.

Regards,
Juan M. Guerrero