Re: Another issue with -O?

[Paul Smith]

On Fri, 2013-05-03 at 14:02 +0200, Reinier Post wrote:
> Reading this discussion, as a bystander I can't help wondering whether
> the addition of -O is worthwhile.  Unix tools are supposed to be
> small and dedicated. Using a separate utility seems to be a clean
> solution here, and that is fact how it was originally done:
> 
>   http://lists.gnu.org/archive/html/bug-make/2011-04/msg00018.html
> 
> Using a separate utility is less performant and more cumbersome,
> but it is more modular.  The semantics are clear.  The utility can
> be documented and developed separately from GNU Make.  As a GNU Make
> user I worry that with the -O option I won't be sure how it works.

Adding -O in no way precludes you from using a separate utility if you
prefer.  And anyway, even with a separate program you'll still have all
the same problems dealing with recursive builds (David, the original
author, doesn't use recursive make IIRC so he doesn't notice these
things :-)).

And I see no possible way of supporting today's -Otarget option using
the external program method with no modifications to make.  I believe
David uses .ONESHELL where there's no difference between multi-line
recipes and single-line recipes.

I think having this facility built into make is a win, especially as
parallel builds become predominant.  I would be even more happy about it
if we can get it to the point where it can be enabled by default, and
users don't even have to worry about it.