Re: [PATCH v2 4/5] Makefile: add the ".DELETE_ON_ERROR" flag

From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: Mar 29, 2021, 23:31 UTC
Message-ID: <87a6qlmt9f.fsf@evledraar.gmail.com>
In-Reply-To: <xmqqblb1kd47.fsf@gitster.g>

On Mon, Mar 29 2021, Junio C Hamano wrote:

Show 15 quoted lines

> Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:
>
>> Use the GNU make ".DELETE_ON_ERROR" flag.
>
> Yay!
>
> With versions of $(MAKE) where this feature is available, it is far
> more preferrable to use it than "generate into temporary and rename
> to the final" dance.
>
> We do require / depend on GNU but I do not offhand know if this is
> available in all versions that still matter.  If we know we can
> assume the presence of this feature the I do not mind if we jump
> directly to this step without those "do the same for $(CC)" steps
> (which I deem crazy) before it.

Even if it's not available in all versions that's OK. You just won't get the nicer removal behavior on on error on such a jurassic gmake, but you'll probably have way bigger issues with your late-90s-era software.

It's not a syntax error on a gmake or other make that doesn't know about it either, i.e. you can also add a target like:

    .THIS_DOES_NOT_EXIST_AS_A_GMAKE_FEATURE:

And gmake willl happily ignore it.