Re: [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 21, 2013, 15:19 UTC
Message-ID: <7vhak4bx0w.fsf@alter.siamese.dyndns.org>
In-Reply-To: <7vppysbxzo.fsf@alter.siamese.dyndns.org>

Junio C Hamano <gitster@pobox.com> writes:

Show 20 quoted lines

> Jeff King <peff@peff.net> writes:
>
>> Git code was my introduction to it, too, and I was led to believe it was
>> idiomatic, so I can't speak further on that. I think it was Junio who
>> introduced me to it, so maybe he can shed more light on the history.
>
> I think we picked the convention up from the kernel folks.  At least
> that is how I first met the construct.  The uninitialized_var(x)
> macro was (and still is) used to mark these "The compiler is too
> dumb to realize, but we know what we are doing" cases:
>
>     $ git grep '#define uninitialized_var' include/
>     include/linux/compiler-gcc.h:#define uninitialized_var(x) x = x
>     include/linux/compiler-intel.h:#define uninitialized_var(x) x
>
> but they recently had a discussion, e.g.
>
>     http://thread.gmane.org/gmane.linux.kernel.openipmi/1998/focus=1383705
>
> so...

While flipping the paragraphs around before sending the message out I managed to lose the important one. Here is roughly what I wrote:

    I am for dropping "= x" and leaving it uninitialized at the
    declaration site, or explicitly initializing it to some
    reasonable starting value (e.g. NULL if it is a pointer) and
    adding a comment to say that the initialization is to squelch
    compiler warnings.