Return-path: Received: from mail.candelatech.com ([208.74.158.172]:54954 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759843Ab2FUTPb (ORCPT ); Thu, 21 Jun 2012 15:15:31 -0400 Message-ID: <4FE372CE.3020105@candelatech.com> (sfid-20120621_211555_282435_F5A652C3) Date: Thu, 21 Jun 2012 12:15:26 -0700 From: Ben Greear MIME-Version: 1.0 To: Rajkumar Manoharan CC: linville@tuxdriver.com, linux-wireless@vger.kernel.org Subject: Re: [PATCH 3/3] ath9k: fix 'side effect in macro' smatch warning References: <1340303492-30947-1-git-send-email-rmanohar@qca.qualcomm.com> <1340303492-30947-4-git-send-email-rmanohar@qca.qualcomm.com> <4FE36B2D.4000407@candelatech.com> <20120621190716.GA30896@vmraj-lnx.users.atheros.com> In-Reply-To: <20120621190716.GA30896@vmraj-lnx.users.atheros.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 06/21/2012 12:07 PM, Rajkumar Manoharan wrote: > On Thu, Jun 21, 2012 at 11:42:53AM -0700, Ben Greear wrote: >> On 06/21/2012 11:31 AM, Rajkumar Manoharan wrote: >>> ath9k_get_et_stats() warn: side effect in macro >>> 'AWDATA' doing 'i++' >>> >>> Cc: Ben Greear >>> Signed-off-by: Rajkumar Manoharan >>> --- >>> drivers/net/wireless/ath/ath9k/main.c | 9 +++++---- >>> 1 file changed, 5 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c >>> index 85f9ab4..32474b0 100644 >>> --- a/drivers/net/wireless/ath/ath9k/main.c >>> +++ b/drivers/net/wireless/ath/ath9k/main.c >>> @@ -2003,10 +2003,11 @@ static int ath9k_get_et_sset_count(struct ieee80211_hw *hw, >>> #define PR_QNUM(_n) (sc->tx.txq_map[_n]->axq_qnum) >>> #define AWDATA(elem) \ >>> do { \ >>> - data[i++] = sc->debug.stats.txstats[PR_QNUM(WME_AC_BE)].elem; \ >>> - data[i++] = sc->debug.stats.txstats[PR_QNUM(WME_AC_BK)].elem; \ >>> - data[i++] = sc->debug.stats.txstats[PR_QNUM(WME_AC_VI)].elem; \ >>> - data[i++] = sc->debug.stats.txstats[PR_QNUM(WME_AC_VO)].elem; \ >>> + data[i+0] = sc->debug.stats.txstats[PR_QNUM(WME_AC_BE)].elem; \ >>> + data[i+1] = sc->debug.stats.txstats[PR_QNUM(WME_AC_BK)].elem; \ >>> + data[i+2] = sc->debug.stats.txstats[PR_QNUM(WME_AC_VI)].elem; \ >>> + data[i+3] = sc->debug.stats.txstats[PR_QNUM(WME_AC_VO)].elem; \ >>> + i += 4; \ >>> } while (0) >> >> The macro is still changing i. So, whatever smatch is, seems it >> should still warn, or it's broken :P >> > No it is not. The warning message is a hint. The smatch assumes that replacing > the macro 'i++' might cause unexpected behaviour like 5++ in each statement. Well, my opinion is that your patch only adds un-needed code and that smatch is either currently giving false-positives, or that it is missing a warning when you add your patch. But, not a big deal either way. Thanks, Ben > > -Rajkumar -- Ben Greear Candela Technologies Inc http://www.candelatech.com