Re: [PATCH, RFC] Fix build problems related to profile-directed optimization

From: Theodore Tso <tytso@mit.edu>
Date: Feb 3, 2012, 18:19 UTC
Message-ID: <BEE56B27-1C86-4C26-A584-3FF179B7A3D6@mit.edu>
In-Reply-To: <7vr4ycsbga.fsf@alter.siamese.dyndns.org>

On Feb 3, 2012, at 1:00 AM, Junio C Hamano wrote:

Show 6 quoted lines

> 
> * I am happy that this version handles this well:
> 
>   $ make PROFILE=BUILD install
> 
>   even though you did not advertise as such in INSTALL ;-).

I can mention it, although it will mean adding more verbiage about profile-directed optimization into the INSTALL.

My assumption was that people who did this would usually be installing into --prefix=/usr as root, but there certainly will be anal people like myself who want to install profile-optimized binaries into ~/bin.  :-)

> * However, I think "clean" target should remove *.gcda unconditionally.
> 
>   $ make PROFILE=BUILD install ; make clean ; git clean -n -x | grep gcda

Will fix.

> * Running "make PROFILE=BUILD install" immediately after another one,
>   without "make clean" in between, resulted in full rebuild and test
>   before the second "install", which somewhat surprised me.  I however do
>   not think this is a big show-stopper problem.

Hmm… that surprises me too.  If

	make PROFILE=BUILD all
	make PROFILE=BUILD install

works correctly, I don't understand why a second "make PROFILE=BUILD install" issued after the above sequence would result in complete rebuild and test pass, unless something in the "make install" rules is modifying the build tree as a side-effect of the install pass, which I'd argue is a bug.  I'll take a look at it.

-- Ted