From: Joshua Juran <jjuran@gmail.com>
Date: Fri, 02 Jul 2010 01:43:47 GMT
Subject: Re: Purpose of "struct object_entry *oe = oe;"?
Message-ID: <69D6E995-8F0E-446C-90CD-758C160A7807@gmail.com>
In-Reply-To: <8039w681lo.fsf@tiny.isode.net>

On Jun 29, 2010, at 5:28 AM, Bruce Stephens wrote:

> Out of curiousity, where did this convention/idiom come from, and  
> what's
> it for?
>
> I presume it's to remove a warning ("oe might be used  
> uninitialised") on
> a compiler (or something) that's clever enough to attempt such  
> analysis
> but too stupid to notice that the supposed initialisation is using
> something uninitialised (or perhaps the compiler's deliberately
> recognising the convention?).  Is that right, or does it actually do
> something more?
>
> I'm mostly surprised that it surprises me.  Is it used commonly in  
> other
> projects?  (It appears not to be mentioned in CodingGuidelines; should
> it be?)

I was wondering this myself.  My compiler complains in (and only in)  
the *presence* of this idiom, rather than its absence, so I undid it:

jj/warn/uninitialized branch on GitHub
http://github.com/jjuran/git/tree/jj/warn/uninitialized

jj/warn/uninitialized commit on GitHub
http://github.com/jjuran/git/commit/ 
8affbf2d8e46fbd5f3d6898aa07ea8548432e7bc
Signed-Off-By:  Joshua Juran <jjuran@gmail.com> (or s/gmail/metamage/)

A compiler that warns of uninitialized usage *unless* a variable is  
initialized *with itself* is doubly broken.

Cheers,
Josh