git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: Jeff King <peff@peff.net>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org
Subject: Re: [PATCH 1/4] Makefile: don't re-define PERL_DEFINES
Date: Thu, 6 May 2021 12:59:02 -0400	[thread overview]
Message-ID: <YJQgVsKdb+gh5Sep@coredump.intra.peff.net> (raw)
In-Reply-To: <87sg30usm9.fsf@evledraar.gmail.com>

On Thu, May 06, 2021 at 11:04:34AM +0200, Ævar Arnfjörð Bjarmason wrote:

> > Actually, strictly speaking there was *no* bug because assigning
> > three items with := made sure the previous recursively expanded one
> > to be ineffective.  In other words, there was a valid reason to use
> > ":=" there in the original version.
> 
> Yes, there wasn't any bug with the the eventual value being
> incorrect. I.e. both of these are equivalent in a Makefile:
> 
>     FOO = abc
>     FOO := def
>     FOO += ghi
> 
> And:
> 
>     FOO = abc
>     FOO = def
>     FOO += ghi
> 
> Both will yield "def ghi". They're just different in a case like:
>     
>     X = Y
>     FOO = abc
>     FOO := $(X)
>     X = Z
>     FOO += ghi
> 
> Where using := will echo "Y ghi", and using = will echo "Z ghi". As a
> practical matter the distinction doesn't matter in this case.

Yeah, I don't think the ":=" was impacting the bug or no bug (not to
mention that even if we duplicated those entries in the variable, it
_still_ wouldn't be a bug, since the whole point of the variable is just
to notice when the content changes).

> > Now your patch removed the recursively expanded one that was
> > immediately invalidated, there no longer is a reason to use :=
> > there.  So "unrelated to the more narrow bugfix" is a rather lame
> > excuse to do only half a task.  If we remove that extra one (which
> > is a good thing), then we should correct := into = because the
> > original used := only because there was the unwanted extra one, no?
> 
> I don't see how removing the stray line changes the reason to use ":="
> or "=" there. I agree it should be removed, it's just unrelated to
> removing the stay line. Looking at 07d90eadb50 it's clear that it's just
> some copy/pasting error.

Yeah, I'd agree it is truly orthogonal. I don't mind seeing it cleaned
up in addition (or am even actively happy to see it cleaned up :) ), but
IMHO it would not need to hold up the series.

-Peff

  reply	other threads:[~2021-05-06 16:59 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-05 12:21 [PATCH 0/4] Makefile/perl: correctly re-generate build/* + speed up under NO_GETTEXT=Y Ævar Arnfjörð Bjarmason
2021-05-05 12:21 ` [PATCH 1/4] Makefile: don't re-define PERL_DEFINES Ævar Arnfjörð Bjarmason
2021-05-05 14:08   ` Jeff King
2021-05-06  1:05     ` Junio C Hamano
2021-05-06 16:55       ` Jeff King
2021-05-06  6:23     ` Ævar Arnfjörð Bjarmason
2021-05-06  8:42       ` Junio C Hamano
2021-05-06  9:04         ` Ævar Arnfjörð Bjarmason
2021-05-06 16:59           ` Jeff King [this message]
2021-05-07  8:42           ` Junio C Hamano
2021-05-05 12:21 ` [PATCH 2/4] Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes Ævar Arnfjörð Bjarmason
2021-05-05 12:21 ` [PATCH 3/4] Makefile: regenerate *.pm on NO_PERL_CPAN_FALLBACKS change Ævar Arnfjörð Bjarmason
2021-05-05 12:21 ` [PATCH 4/4] perl: use mock i18n functions under NO_GETTEXT=Y Ævar Arnfjörð Bjarmason
2021-05-10 10:50 ` [PATCH v2 0/6] Makefile/perl: correctly re-generate build/* + speed up " Ævar Arnfjörð Bjarmason
2021-05-10 10:50   ` [PATCH v2 1/6] Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes Ævar Arnfjörð Bjarmason
2021-05-10 10:50   ` [PATCH v2 2/6] Makefile: don't re-define PERL_DEFINES Ævar Arnfjörð Bjarmason
2021-05-10 10:50   ` [PATCH v2 3/6] Makefile: make PERL_DEFINES recursively expanded Ævar Arnfjörð Bjarmason
2021-05-10 10:50   ` [PATCH v2 4/6] Makefile: split up the deceleration of PERL_DEFINES Ævar Arnfjörð Bjarmason
2021-05-10 10:50   ` [PATCH v2 5/6] Makefile: regenerate *.pm on NO_PERL_CPAN_FALLBACKS change Ævar Arnfjörð Bjarmason
2021-05-10 10:50   ` [PATCH v2 6/6] perl: use mock i18n functions under NO_GETTEXT=Y Ævar Arnfjörð Bjarmason
2021-05-10 18:17   ` [PATCH v2 0/6] Makefile/perl: correctly re-generate build/* + speed up " Junio C Hamano
2021-05-11  6:56     ` Ævar Arnfjörð Bjarmason
2021-05-11  7:05       ` Junio C Hamano
2021-05-12  9:49         ` [PATCH] Makefile: make PERL_DEFINES recursively expanded Ævar Arnfjörð Bjarmason
2021-05-12 19:53           ` Jeff King
2021-05-12 22:45             ` Junio C Hamano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YJQgVsKdb+gh5Sep@coredump.intra.peff.net \
    --to=peff@peff.net \
    --cc=avarab@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --subject='Re: [PATCH 1/4] Makefile: don'\''t re-define PERL_DEFINES' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Code repositories for project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).