Re: how to enforce ordering on a set of targets?

[Noel Yap]

Paul D. Smith wrote:

> %% Noel Yap <address@hidden> writes:
>
>   ny> Robert P. J. Day wrote:
>
>   >> *now*, i want to add another target, "populate", which works almost
>   >> the same way but it has to do some preliminary processing in this
>   >> makefile before the recursive (potentially parallel) call to the
>   >> subdirectories.
>   >> 
>   >> if i call this preliminary processing step, say, "pre-populate", i
>   >> can't just do this:
>   >> 
>   >> populate: pre-populate ${SUBDIRS}
>   >> 
>   >> as those steps would be allowed to be done in parallel, which is not
>   >> good.  and i can't add
>   >> 
>   >> ${SUBDIRS}: pre-populate
>   >> 
>   >> since that dependency should *only* take effect when i'm invoking the
>   >> makefile with the "populate" target, and no others.
>
>   ny> Then it sounds like you need to use order rules.
>
> Order rules won't keep the dependency from taking effect if the
> "populate" target is not specified.

I don't understand.  Wouldn't it be possible to do:

.PHONY: populate
populate: pre-populate | ${SUBDIRS}

Noel