[Bug c/67930] New: segmentation fault

[Bug c/67930] New: segmentation fault

[ka_bena at yahoo dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67930

            Bug ID: 67930
           Summary: segmentation fault
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ka_bena at yahoo dot fr
  Target Milestone: ---

# include <stdlib.h>
# include <stdio.h>

void test ( char **A )
{
 *A[0] = 'a' ;
}

int main( void)
{
 char *b = "omega" ;

 test ( &b ) ;

 printf ( "b = %s \n" , b ) ;

 return 0 ;

}

/*
RESULTS::
Segmentation fault (core dumped)
Exited: 35584

 gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04)
 gcc -std=gnu99 -omain_pointer.exe main_pointer.c ;
*/

[Bug c/67930] segmentation fault

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67930

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |mpolacek at gcc dot gnu.org
         Resolution|---                         |INVALID

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
You're trying to modify a string literal.  That's no-no.

[Bug c/67930] segmentation fault

[ka_bena at yahoo dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67930

--- Comment #2 from BENAÏSSA <ka_bena at yahoo dot fr> ---

 Thank you for your reply.

 Comments::

 I am not convinced by your point of view.

 1- the compilation step does not deliver any message.

 2- I modify the string by address and this is permitted by C for any entity
not 
    private in its context.

 3- if the compiler gcc allows segmentation fault for basic operations on
pointers,
    I think that this is a severe bug and in consequence the compiler must be
    modified to remedie for such situations.

 This is my point of view.    
                                    A.Benaïssa 


     Le Lundi 12 octobre 2015 13h16, mpolacek at gcc dot gnu.org
<gcc-bugzilla@gcc.gnu.org> a écrit :


 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67930

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

          What    |Removed                    |Added
----------------------------------------------------------------------------
            Status|UNCONFIRMED                |RESOLVED
                CC|                            |mpolacek at gcc dot gnu.org
        Resolution|---                        |INVALID

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
You're trying to modify a string literal.  That's no-no.
>From gcc-bugs-return-499470-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Tue Oct 13 14:43:34 2015
Return-Path: <gcc-bugs-return-499470-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Delivered-To: listarch-gcc-bugs@gcc.gnu.org
Received: (qmail 84147 invoked by alias); 13 Oct 2015 14:43:34 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Delivered-To: mailing list gcc-bugs@gcc.gnu.org
Received: (qmail 84124 invoked by uid 48); 13 Oct 2015 14:43:30 -0000
From: "Pidgeot18 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug gcov-profile/67937] gcov gives wrong results when negative counts are involved
Date: Tue, 13 Oct 2015 14:43:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: gcov-profile
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: Pidgeot18 at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution:
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-67937-4-cMpFqNwyJR@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-67937-4@http.gcc.gnu.org/bugzilla/>
References: <bug-67937-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-10/txt/msg01025.txt.bz2
Content-length: 331

https://gcc.gnu.org/bugzilla/show_bug.cgi?idg937

--- Comment #4 from Joshua Cranmer <Pidgeot18 at gmail dot com> ---
(In reply to Richard Biener from comment #3)
> Most interesting would be a C testcase that produces the CFG with the bogus
> counters ;)

Yeah, I know, but doing the minimization on a 5MLOC program takes time.

[Bug c/67930] segmentation fault

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67930

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Try adding -W -Wall and also -WWrite-string