From: Jeff King <peff@peff.net>
Date: Wed, 15 Apr 2009 07:58:19 GMT
Subject: Re: [PATCH] Documentation/CodingGuidelines: improve header includes rules
Message-ID: <20090415075819.GC23332@coredump.intra.peff.net>
In-Reply-To: <20090414003433.39cbdea2.chriscool@tuxfamily.org>

On Tue, Apr 14, 2009 at 12:34:33AM +0200, Christian Couder wrote:

> 	- The third one means that for example if we have "revision.h"
> 	that includes "diff.h" and "commit.h", then it's ok to include
> 	"revision.h" in a C file, only if at least one feature from
> 	"revision.h" is actually used in the C file.
> 
> 	It is not ok to include "revision.h" if features from "diff.h"
> 	and "commit.h" are used but no feature from "revision.h" is
> 	used.

Why? I thought the guiding principle mentioned earlier was "don't waste
programmers' time figuring out what should and shouldn't be included".

Sure, I would not expect somebody to include a header that is totally
unrelated, but it seems that most of the source files lazily include
cache.h just to get "everything".

Stripping unnecessary includes doesn't even speed up compilation, as our
Makefile overspecifies the header dependencies anyway.

-Peff