Re: Feature request / patch: dependency-only prerequisites

[Christof Warlich]

Am 09.07.19 um 20:52 schrieb Paul Smith:

> https://savannah.gnu.org/bugs/?func=additem&group=make
> You don't have to make an account in order to file a bug, but be sure
> to add yourself to mail notifications if you don't create an account,
> or you won't get any updates.
Ok, but considering your suggestion below, I doubt that it
makes much sense to still file my initial approach.
> My first reaction is that this solution seems like a very big hammer
> (in terms of changes to makefile syntax) to handle a relatively rare
> and specific situation.  I wonder if there's an alternative that gives
> the same result but is a bit less intrusive.
>
> What if we do this instead: create a variable which can contain a list
> of "hidden prerequisites": they will always be built first but they
> won't cause any changes in the automatic variables.  If set globally it
> will apply to all targets.  If set as a target-specific variable then
> it applies only to that target (and its prerequisites, which can be
> remediated with the private keyword).
>
> This seems like it could be something generally useful, to ensure some
> targets are always built first, as well as useful in this context.

AFAICS, this would serve my desires at least equally well. And the
more I think about it, the more I get convinced that it would be
the superior approach for a couple of reasons, like better readability,
almost no syntactical change, ...

Furthermore, this variable may quite naturally even honor order-only
prerequisites by including the pipe character at any point in its
prerequisite list.

> On another topic, note that these changes are of a size that they do
> meet the requirement for copyright assignment before they can be
> applied.  I can forward you the details if that's something you're
> interested in.
>
> Cheers!
I certainly would be happy to sign any copyright requirements needed.
But just let me know what would be most conveniet for _you_ to proceed:

Would it really help if I try to supply a patch that implements your idea?
Or is the current "state of affairs" sufficient that the general idea (i.e.
allowing to add target specific prerequisites without changing automatic
variables) will eventually go into some future version of GNU Make?

Cheers,

Chris