From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752610AbbIQSdR (ORCPT <rfc822;w@1wt.eu>);
	Thu, 17 Sep 2015 14:33:17 -0400
Received: from mail.kernel.org ([198.145.29.136]:51262 "EHLO mail.kernel.org"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752150AbbIQSdK (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 17 Sep 2015 14:33:10 -0400
Date: Thu, 17 Sep 2015 15:33:03 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: a.p.zijlstra@chello.nl, mingo@redhat.com, jolsa@kernel.org,
        matt.fleming@intel.com, namhyung@kernel.org, milos@redhat.com,
        kan.liang@intel.com, rostedt@goodmis.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tools-perf: Change -1 by false
Message-ID: <20150917183303.GO11551@kernel.org>
References: <1442484533-19742-1-git-send-email-peter.senna@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1442484533-19742-1-git-send-email-peter.senna@gmail.com>
X-Url: http://acmel.wordpress.com
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Em Thu, Sep 17, 2015 at 12:08:53PM +0200, Peter Senna Tschudin escreveu:
> Returning a negative value for a boolean function seem to have the
> undesired effect of returning true. Replace -1 by false in a
> bool-returning function.
> 
> The diff of the .s file before and after the change (for x86_64):
> 3907c3907
> < 	movl	$1, %ebx
> ---

Please avoid adding a --- at the start of any changeset comment line, it
breaks scripts.

Thanks, applied.

- Arnaldo

> > 	xorl	%ebx, %ebx
> 
> while if -1 is replaced by true, the diff is empty.
> 
> This issue was found by the following Coccinelle semantic patch:
> <smpl>
> @@
> identifier f;
> constant C;
> typedef bool;
> @@
> bool f (...){
> <+...
> * return -C;
> ...+>
> }
> </smpl>
> 
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
> ---
>  tools/perf/util/util.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> index 49a5c6a..ce465b2 100644
> --- a/tools/perf/util/util.c
> +++ b/tools/perf/util/util.c
> @@ -639,7 +639,7 @@ bool find_process(const char *name)
>  
>  	dir = opendir(procfs__mountpoint());
>  	if (!dir)
> -		return -1;
> +		return false;
>  
>  	/* Walk through the directory. */
>  	while (ret && (d = readdir(dir)) != NULL) {
> -- 
> 2.1.0