From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH] examples/distributor: fix missing ";
 " in debug macro
Date: Tue, 9 Jun 2015 17:33:58 -0700
Message-ID: <20150609173358.267e3281@urahara>
References: <1433520077-11234-1-git-send-email-bruce.richardson@intel.com>
 <19910784.6F5piXXB0d@xps13> <20150608105810.GC3996@bricha3-MOBL3>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: dev@dpdk.org
To: Bruce Richardson <bruce.richardson@intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from mail-qg0-f53.google.com (mail-qg0-f53.google.com
 [209.85.192.53]) by dpdk.org (Postfix) with ESMTP id AC9465A6F
 for <dev@dpdk.org>; Wed, 10 Jun 2015 02:33:56 +0200 (CEST)
Received: by qgg3 with SMTP id 3so11193402qgg.2
 for <dev@dpdk.org>; Tue, 09 Jun 2015 17:33:56 -0700 (PDT)
In-Reply-To: <20150608105810.GC3996@bricha3-MOBL3>
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Mon, 8 Jun 2015 11:58:10 +0100
Bruce Richardson <bruce.richardson@intel.com> wrote:

> On Fri, Jun 05, 2015 at 10:45:04PM +0200, Thomas Monjalon wrote:
> > 2015-06-05 17:01, Bruce Richardson:
> > > The macro to turn on additional debug output when the app was compiled
> > > with "-DDEBUG" was missing a ";".
> > 
> > It shows that such dead code is almost never tested.
> > It would be saner if this command would return no result:
> > 	git grep 'ifdef.*DEBUG' examples
> > 		examples/distributor/main.c:#ifdef DEBUG
> > 		examples/l3fwd-acl/main.c:#ifdef L3FWDACL_DEBUG
> > 		examples/l3fwd-acl/main.c:#ifdef L3FWDACL_DEBUG
> > 		examples/l3fwd-acl/main.c:#ifdef L3FWDACL_DEBUG
> > 		examples/l3fwd-acl/main.c:#ifdef L3FWDACL_DEBUG
> > 		examples/packet_ordering/main.c:#ifdef DEBUG
> > 		examples/vhost/main.c:#ifdef DEBUG
> > 		examples/vhost/main.h:#ifdef DEBUG
> > 		examples/vhost_xen/main.c:#ifdef DEBUG
> > 		examples/vhost_xen/main.h:#ifdef DEBUG
> > 
> > There is no good reason to not use CONFIG_RTE_LOG_LEVEL to trigger debug build.
> > 
> I agree and disagree. 
> 
> I agree it would be good if we had a standard way of setting up
> a DEBUG build that would make it easier to test and pick up on this sort of things.
> 
> I disagree that the compile time log level is the way to do this. The log level
> at compile time specifies the default log level only, the actual log level is
> controllable at runtime. Having the default log level also affect what kind of
> build is done, e.g. with -O0 rather than -O3, introduces an unnecessary dependency.
> Setting the default log level to 5 and changing it to 9 at runtime should be
> the same as setting the default to 9.
> 
> /Bruce

One good way is to use something like:

#ifdef DEBUG
 #define LOG_DEBUG(log_type, fmt, args...) do {	\
-	RTE_LOG(DEBUG, log_type, fmt, ##args)		\
+	RTE_LOG(DEBUG, log_type, fmt, ##args);		\
 } while (0)
#else
#define LOG_LEVEL RTE_LOG_INFO
#define LOG_DEBUG(log_type, fmt, args...) if (0) {	\
	RTE_LOG(DEBUG, log_type, fmt, ##args);		\
 } else
#endif