Re: suddenly, "recursive make considered harmful" makes piles of sense

[Alessandro Vesely]

Boris Kolpackov wrote:
>
> There is also a third "philosophy": gmake within any directory will
> build that directory and all its dependencies and any subdirectories
> and all their dependencies. For example:
> 
> root
>  |
>  +--libfoo
>  |
>  +--foo
> 
> Say root/foo depends on root/libfoo. If you say make inside root/foo
> and root/libfoo is not up-to-date, it will be built before building
> root/foo. Very handy.

What was that about? Since the manual says "The criterion for being out of
date is specified in terms of the prerequisites, which consist of file
names separated by spaces," how can root/foo depend on root/libfoo?

If I just mention a directory that contains a Makefile I get

  Considering target file `libfoo'.
   Looking for an implicit rule for `libfoo'.
   [...]
   No implicit rule found for `libfoo'.
   Finished prerequisites of target file `libfoo'.
  No need to remake target `libfoo'.

Anyway, I note that the fact that it is named `Makefile' does not
prevent one for including it. So it should be enough to have one
of those per directory.