Re: Detect --disable-dependency-tracking in Makefile.am

[Dave Hart]

On Sat, 30 Sept 2023 at 05:07, Jan Engelhardt <jengelh@inai.de> wrote:

> On Saturday 2023-09-30 05:27, Dave Hart wrote:
>
> >I've added code to the ntp.org Makefile.am files to ensure the static
> >utility library libntp.a is up-to-date for each program that uses it, to
> >ensure the build is correct.  When building the project, this adds a bunch
> >of extra submake invocations which slows down the build.  I'd like to omit
> >those when --disable-dependency-tracking is used, to speed one-off builds
> >that are done by end-users and packagers.
>
> submake is pretty much independent of and from dependency tracking.
>
> The general direction contemporary projects take is to just not do submake
> anymore, because it's a slowdown whether or not deptracking is used.
>

I didn't explain sufficiently.  The submakes I'm talking about are my
doing, and I want to conditionalize them on whether
--enable-dependency-tracking is used.

In for example both ntpq/Makefile.am and ntpd/Makefile.am I'm invoking:

(cd ../libntp && make libntp.a)

This is for my convenience as a developer so that any changes I make to
libntp sources trigger its rebuild even if I'm invoking make in just one
subdirectory (say ntpd) rather than the root of the Automake project.

This slows down a one-shot build from source quite a bit, since there are a
half-dozen client directories and there are a lot of rules in
libntp/Makefile.am.  So I want to be sure that when
--disable-dependecy-tracking has been passed to configure, as is often done
by packagers, we omit those as the order of Makefile.am subdirs ensures
libntp.a is built before consumers.

Thanks for your response,
Dave Hart