From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 02 Jan 2013 20:25:09 GMT
Subject: Re: [PATCH v2] build: do not automatically reconfigure unless configure.ac changed
Message-ID: <7vbod72uze.fsf@alter.siamese.dyndns.org>
In-Reply-To: <50E48BF6.2020900@gmail.com>

Stefano Lattarini <stefano.lattarini@gmail.com> writes:

>>  ifdef AUTOCONFIGURED
>> -config.status: configure
>> -	$(QUIET_GEN)if test -f config.status; then \
>> +# We avoid depending on 'configure' here, because it gets rebuilt
>> +# every time GIT-VERSION-FILE is modified, only to update the embedded
>> +# version number string, which config.status does not care about.
>>
> Alas, config.status *do* care about it, in that the '@PACKAGE_VERSION@',
> '@PACKAGE_STRING@' and '@DEFS@' substitutions are affected by what is
> hard-coded in configure as the version number [1].  But if we do not
> use those substitutions in any of our files (and I believe we don't),
> then *we* can happily not care about the configure embedded version
> number string, and thus avoid the extra configure runs.  Phew.
>
>  [1] Yes, this is a mess.  We know.  Sorry!

Heh.  Should we warn against the use of these symbols somewhere in
configure.ac, perhaps, then?