linux-kernel - Re: [PATCH 2/7] tracing: Change strlen to sizeof for hist trigger static strings

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Message-ID: <1545251919.4161.4.camel@kernel.org>
Date:   Wed, 19 Dec 2018 14:38:39 -0600
From:   Tom Zanussi <zanussi@...nel.org>
To:     Steven Rostedt <rostedt@...dmis.org>, Joe Perches <joe@...ches.com>
Cc:     tglx@...utronix.de, mhiramat@...nel.org, namhyung@...nel.org,
        vedang.patel@...el.com, bigeasy@...utronix.de,
        joel@...lfernandes.org, mathieu.desnoyers@...icios.com,
        julia@...com, linux-kernel@...r.kernel.org,
        linux-rt-users@...r.kernel.org
Subject: Re: [PATCH 2/7] tracing: Change strlen to sizeof for hist trigger
 static strings

On Wed, 2018-12-19 at 15:30 -0500, Steven Rostedt wrote:
> On Wed, 19 Dec 2018 12:20:19 -0800
> Joe Perches <joe@...ches.com> wrote:
> 
> > > Yeah, I had considered it but wasn't sure it was worth it.  Since
> > > you're suggesting it is, I can send another patch on top of
> > > these, or
> > > feel free if you want to too.  ;-)  
> > 
> > I believe the 'strlen("foo") -> sizeof("foo") - 1'
> > conversions do not change objects at all.
> > 
> > strlen("constant") is already optimized by gcc to a
> > constant value when fed a constant string.
> 
> If that's the case (and it probably is), then yeah, strlen is
> probably
> better. As it can handle the "not a constant" that you stated in
> another email.
> 

OK, so I guess that means we should just drop this patch ('[PATCH 2/7]
tracing: Change strlen to sizeof for hist trigger static strings').

Tom

> -- Steve
> 
> 
> > 
> > the strcmp_const macro does seem to make sense as
> > the copy/paste/typo possibility is real.
> 
>