From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751353Ab1AEDKX (ORCPT ); Tue, 4 Jan 2011 22:10:23 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:37084 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751010Ab1AEDKW (ORCPT ); Tue, 4 Jan 2011 22:10:22 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=HWG5ICy/MRcotv4rJixC0q/WXyGJ4geKbI9kXJg5RsB3sgbErFSokLCmHHbMf4WK2v 9We7WJ4DRGyyKjVXocrYbe3XmzL8BinAWGowCpILoDmsGO473rs4aNsyE0LGSpzkHlZS GjlhqbCPBw4FVvlkjpGExM6QBgs615T0S9PDE= Date: Wed, 5 Jan 2011 04:10:18 +0100 From: Frederic Weisbecker To: Valdis.Kletnieks@vt.edu Cc: Mathieu Desnoyers , LKML , Steven Rostedt , Ingo Molnar , Thomas Gleixner Subject: Re: [RFC patch 3/5] ftrace trace event add missing semicolumn Message-ID: <20110105031016.GI2911@nowhere> References: <20110104231629.996422888@efficios.com> <20110104232419.441463699@efficios.com> <20110105000005.GE2911@nowhere> <20110105001837.GA9737@Krystal> <20110105020759.GG2911@nowhere> <12932.1294196493@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <12932.1294196493@localhost> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 04, 2011 at 10:01:33PM -0500, Valdis.Kletnieks@vt.edu wrote: > On Wed, 05 Jan 2011 03:08:02 +0100, Frederic Weisbecker said: > > On Tue, Jan 04, 2011 at 07:18:37PM -0500, Mathieu Desnoyers wrote: > > > > > > --- linux-2.6-lttng.orig/include/trace/ftrace.h > > > > > +++ linux-2.6-lttng/include/trace/ftrace.h > > > > > @@ -69,7 +69,7 @@ > > > > > #undef DEFINE_EVENT > > > > > #define DEFINE_EVENT(template, name, proto, args) \ > > > > > static struct ftrace_event_call __used \ > > > > > - __attribute__((__aligned__(4))) event_##name > > > > > + __attribute__((__aligned__(4))) event_##name; > > > > Adding this semicolumn here ensures that all Ftrace macros are consistent wrt > > > semicolumns. We can get away without consistency currently exactly because the > > > current scheme adds many useless semicolumns between each TRACE_EVENT(). > > > Are you sure you want to put so much time on this? > > > This will require a massive change for the sole win of removing double ";" > > in generated code. This won't optimize much the build, and it will make the things > > not so much more readable for very rare people who dare to have interest into the > > TRACE_EVENT generated code. That notwithstanding the obfuscation of that generated > > code resides more in the lack of indentation and newlines than in double > > semicolons that we barely notice. > > Can DEFINE_EVENT ever be sensibly used in a context where the additional ; will > cause an issue (for instance, a hypothetical array initialization like: > > static struct events[] = {DEFINE_EVENT(..), DEFINE_EVENT(...) } You can't do the above as DEFINE_EVENT() do more than just creating a structure. It can define functions and so. Plus it doesn't behave the same whether CREATE_TRACE_POINTS is defined or not: it can either define or declare the functions and structures. > or other places we usually do the 'do { X } while (0)' trick to make the code legal? I just can't figure out a sane case.