X-Recipient: archive-cygwin AT delorie DOT com
X-Spam-Check-By: sourceware.org
To: cygwin AT cygwin DOT com
From: Ray Hurst <rhurst2 AT cox DOT net>
Subject:  Re: Issue with GDB under Cygwin and XP
Date:  Wed, 13 Feb 2008 10:45:14 -0800
Lines: 106
Message-ID: <fovdsg$qbq$1@ger.gmane.org>
References:  <for5v0$qcr$1 AT ger DOT gmane DOT org> <fotqic$eoq$1 AT ger DOT gmane DOT org>
Mime-Version:  1.0
Content-Type:  text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding:  7bit
User-Agent: Thunderbird 2.0.0.9 (Windows/20071031)
In-Reply-To: <fotqic$eoq$1@ger.gmane.org>
X-IsSubscribed: yes
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Precedence: bulk
List-Id: <cygwin.cygwin.com>
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

Jim Marshall wrote:
> Ray Hurst wrote:
>> I'm running under Windows XP and Cygwin.
>>
>> I ran GDB on a simple C program and captured the output (below).
>> I have a few questions:
>>
>> Why can I run the program several times with no errors but as soon as 
>> I set a breakpoint at main it gets a SIGSEGV fault?
>>
>> Why does the backtrace show only addresses?
>>
>>
>> C:\Documents and Settings\Ray 
>> Hurst\workspace\CDT\HelloWorld-ANSIC\Debug>gdb Hel
>> loWorld-ANSIC.exe
>> GNU gdb 6.5.50.20060706-cvs (cygwin-special)
>> 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 "i686-pc-cygwin"...
>> (gdb) list
>> 5        Version     :
>> 6        Copyright   : Your copyright notice
>> 7        Description : Hello World in C, Ansi-style
>> 8 =======================================================================
>> =====
>> 9        */
>> 10
>> 11      #include <stdio.h>
>> 12      #include <stdlib.h>
>> 13
>> 14      int main(void) {
>> (gdb) list 20
>> 15              puts("!!!Hello World!!!"); /* prints !!!Hello World!!! */
>> 16              return EXIT_SUCCESS;
>> 17      }
>> (gdb) run
>> Starting program: /cygdrive/c/Documents and Settings/Ray 
>> Hurst/workspace/CDT/Hel
>> loWorld-ANSIC/Debug/HelloWorld-ANSIC.exe
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/ntdll.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/kernel32.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/cygwin1.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/advapi32.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/rpcrt4.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/secur32.dll
>> !!!Hello World!!!
>>
>> Program exited normally.
>> (gdb) run
>> Starting program: /cygdrive/c/Documents and Settings/Ray 
>> Hurst/workspace/CDT/Hel
>> loWorld-ANSIC/Debug/HelloWorld-ANSIC.exe
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/ntdll.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/kernel32.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/cygwin1.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/advapi32.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/rpcrt4.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/secur32.dll
>> !!!Hello World!!!
>>
>> Program exited normally.
>> (gdb) b main
>> Breakpoint 1 at 0x401050: file ../src/HelloWorld-ANSIC.c, line 14.
>> (gdb) run
>> Starting program: /cygdrive/c/Documents and Settings/Ray 
>> Hurst/workspace/CDT/Hel
>> loWorld-ANSIC/Debug/HelloWorld-ANSIC.exe
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/ntdll.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/kernel32.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/cygwin1.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/advapi32.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/rpcrt4.dll
>> Loaded symbols for /cygdrive/c/WINDOWS/system32/secur32.dll
>>
>> Program received signal SIGSEGV, Segmentation fault.
>> [Switching to thread 4896.0x1314]
>> 0x000007f4 in ?? ()
>> (gdb) bt
>> #0  0x000007f4 in ?? ()
>> #1  0x00000000 in ?? ()
>> (gdb)
>>
>> Ray
>>
>>
> Works fine on my Windows XP Pro machine using the same GDB and gcc 
> version 3.4.4. What gcc version do you have?
> 
> The stack trace would indicate that the crash is occurring before it 
> gets to your main function, since that code doesn't have debug symbols 
> you get addresses.
> 
> 

Jim,
It's definitely crashing before getting to main and I don't know why.
The tools versions are: gcc 4.2.3, binutils 2.17.50, and gdb 6.5.50.

Ray


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/