From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Subject: Re: Possible code defects: macros and precedence Date: Tue, 20 Sep 2016 11:03:44 -0700 Message-ID: <1474394624.1954.45.camel@perches.com> References: <1472927739.5018.13.camel@perches.com> <1473001581.5018.37.camel@perches.com> <1474147658.1954.1.camel@perches.com> <1474191110.1954.16.camel@perches.com> <1474391253.1954.39.camel@perches.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8bit Cc: Dan Carpenter , LKML , Andrew Morton , netdev To: Julia Lawall Return-path: In-Reply-To: <1474391253.1954.39.camel@perches.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 2016-09-20 at 10:07 -0700, Joe Perches wrote: > On Tue, 2016-09-20 at 15:14 +0200, Julia Lawall wrote: > > The semantic patch below finds a binary operator in a macro and a binary > > operator in the use of the macro, and checks if the priority of the > > operator in the macro is higher (lower number) than the priority of the > > operator in the use.  If this is the case, it adds parentheses in the use, > > which is not what one wants, but serves to show where the problem is > Thanks, this works on the trivial example I suggested > without an #include > > I've tried it on trivial files with --recursive-includes > and it seems to work there too. I tried it on drivers/net with --recursive-includes and got just 1 hit on an old and probably relatively untested driver. No hardware, can't test. It may be correct now. Who knows... --- diff --urN a/drivers/net/ethernet/smsc/smc911x.h b/drivers/net/ethernet/smsc/smc911x.h --- a/drivers/net/ethernet/smsc/smc911x.h +++ b/drivers/net/ethernet/smsc/smc911x.h @@ -700,8 +700,8 @@ static const struct chip_id chip_ids[] = * capabilities. Please use those and not the in/out primitives. */ /* FIFO read/write macros */ -#define SMC_PUSH_DATA(lp, p, l) SMC_outsl( lp, TX_DATA_FIFO, p, (l) >> 2 ) -#define SMC_PULL_DATA(lp, p, l) SMC_insl ( lp, RX_DATA_FIFO, p, (l) >> 2 ) +#define SMC_PUSH_DATA(lp, p, l) SMC_outsl( lp, TX_DATA_FIFO, p, ((l) >> 2) ) +#define SMC_PULL_DATA(lp, p, l) SMC_insl ( lp, RX_DATA_FIFO, p, ((l) >> 2) ) #define SMC_SET_TX_FIFO(lp, x) SMC_outl( x, lp, TX_DATA_FIFO ) #define SMC_GET_RX_FIFO(lp) SMC_inl( lp, RX_DATA_FIFO )