From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dj@redhat.com>
Received: from us-smtp-delivery-1.mimecast.com
 (us-smtp-delivery-1.mimecast.com [205.139.110.120])
 by sourceware.org (Postfix) with ESMTP id 809B7385BF92
 for <libc-alpha@sourceware.org>; Wed,  1 Apr 2020 20:34:13 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 809B7385BF92
Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com
 [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id
 us-mta-92-0MGYKY_DO1eEVvJnf5dXsQ-1; Wed, 01 Apr 2020 16:34:11 -0400
X-MC-Unique: 0MGYKY_DO1eEVvJnf5dXsQ-1
Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com
 [10.5.11.11])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C8161937FC1;
 Wed,  1 Apr 2020 20:34:10 +0000 (UTC)
Received: from greed.delorie.com (ovpn-114-252.phx2.redhat.com [10.3.114.252])
 by smtp.corp.redhat.com (Postfix) with ESMTPS id 3E265DA10A;
 Wed,  1 Apr 2020 20:34:10 +0000 (UTC)
Received: from greed.delorie.com.redhat.com (localhost [127.0.0.1])
 by greed.delorie.com (8.14.7/8.14.7) with ESMTP id 031KY9sf009055;
 Wed, 1 Apr 2020 16:34:09 -0400
From: DJ Delorie <dj@redhat.com>
To: Girish Joshi <girish946@gmail.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH] manual: Fix backtraces code example [BZ #10441]
In-Reply-To: <CALkY8p8uOzKkX80a-gw9eoHfTios2Q2fLu33po-NyFhTGDcUeQ@mail.gmail.com> (message
 from Girish Joshi on Tue, 10 Mar 2020 21:40:29 +0530)
Date: Wed, 01 Apr 2020 16:34:09 -0400
Message-ID: <xnk12zeyim.fsf@greed.delorie.com>
MIME-Version: 1.0
X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11
X-Mimecast-Spam-Score: 0
X-Mimecast-Originator: redhat.com
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable
X-Spam-Status: No, score=-14.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH,
 DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE,
 SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: libc-alpha@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Libc-alpha mailing list <libc-alpha.sourceware.org>
List-Unsubscribe: <http://sourceware.org/mailman/options/libc-alpha>,
 <mailto:libc-alpha-request@sourceware.org?subject=unsubscribe>
List-Archive: <http://sourceware.org/pipermail/libc-alpha/>
List-Post: <mailto:libc-alpha@sourceware.org>
List-Help: <mailto:libc-alpha-request@sourceware.org?subject=help>
List-Subscribe: <http://sourceware.org/mailman/listinfo/libc-alpha>,
 <mailto:libc-alpha-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Wed, 01 Apr 2020 20:34:14 -0000


LGTM but I've noted some suggestions for clarity too.

Reviewed-by: DJ Delorie <dj@redhat.com>


Girish Joshi <girish946@gmail.com> writes:
> Validation for pointer returned by backtrace_symbols () added.

Do we want to add some printf for the "else" case?  I don't think it
adds to the example...

> Type of variables size and i is changed from size_t to int.

Protypes are (stripped):

extern int backtrace (void **__array, int __size);
extern char **backtrace_symbols (void *const *__array, int __size);

So "int" for size is OK.  i loops size, so "int" for i also ok.


>    void *array[10];
> -  size_t size;
>    char **strings;
> -  size_t i;
> +  int size, i;

Ok; prototypes call for "int" not "size_t".

>    size =3D backtrace (array, 10);
>    strings =3D backtrace_symbols (array, size);
> +  if (strings)
> +  {

Checking for valid pointer should be "if (strings !=3D NULL)" in our
coding standards, but OK.

> -  printf ("Obtained %zd stack frames.\n", size);
> -
> -  for (i =3D 0; i < size; i++)
> -     printf ("%s\n", strings[i]);
> +    printf ("Obtained %d stack frames.\n", size);

%zd -> %d, no other changes.

> +    for (i =3D 0; i < size; i++)
> +      printf ("%s\n", strings[i]);

Indent only, ok.

> +  }

close new block, ok.