Re: PATCH] remove duplicate #include directives

From: René Scharfe <l.s.r@web.de>
Date: Oct 6, 2019, 10:16 UTC
Message-ID: <5af3ad29-5127-b5f7-46c9-f1d3d45b4e67@web.de>
In-Reply-To: <xmqqv9t269qk.fsf@gitster-ct.c.googlers.com>

Am 06.10.19 um 01:41 schrieb Junio C Hamano:

Show 13 quoted lines

> René Scharfe <l.s.r@web.de> writes:
>> This one here requires one more piece of information, though, namely our
>> convention of wrapping header files in guard defines to make repeated
>> includes of them no-ops.  We do that for those removed by the patch, but
>> we have a few exceptions to that rule in our repo (at least
>> command-list.h, kwset.h, sha1dc_git.h, tar.h, unicode-width.h).  So in
>> that sense it's not such a good example of a self-sufficient patch. :)
>
> Not really.  "We use header guards" is an argument that demotes this
> cleanup from "must have" to "nice to have".  If a project did not
> use header guards or including the same header twice were an error,
> the patch in question would have been more necessary, but that
> wouldn't have changed the correctness of the patch, I think.

You start with "No", but make my point -- a reader would need more information than the content of the patch itself to classify it as a trivial cleanup, namely knowledge of our use of include guards.

Here is an example of a non-idempotent header:

   #define NDEBUG
   ...
   #include <assert.h>
   ...
   #undef NDEBUG
   ...
   #include <assert.h>

(That's the only one we use that I'm aware of.)

René