Re: Checking alternatives for a dynamic make rule construction

[Paul Smith]

On Thu, 2017-06-15 at 17:18 +0200, SF Markus Elfring wrote:
> define rule_pair =
> name::=$(1)
> $$(name:.ml=.cmo): $$(name)
>         $$(OCAMLC_CMD) -c $$<
> 
> $$(name:.ml=.cmx): $$(name)
>         $$(OCAMLOPT_CMD) -c $$<
> endef
> 
> $(foreach x,$(SRC_without_mli),$(eval $(call rule_pair,$(x))))

What Philip is saying (and I agree 100%) is that you provide the above
example which is excellent and helpful and allows us to see exactly what
you're doing.  Thank you for that.

But then, you ask questions which are abstract and require a lot of
effort on our part to understand.  We all have a lot of demands on our
time so the less effort we need to make to help someone, the more likely
that help is to be offered.  For example:

> 2. The specification “$$(name)” is working. Would it make sense to avoid
>    such a variable reference there?
>    Unfortunately, the simple specification “$(1)” does not work in the way
>    I would expect for the selection of a single file as a dependency.
>    Would you like to explain this software behaviour?

This seems to say that when you tried to use something different than
the $$(name) reference above, it didn't work the way you expected. 
However, you provide no information on what the "something different"
that you tried was, how it worked, or how you expected it to work.  In
programming (and makefiles) everything is about the details.  The
statement "I would expect for the selection of a single file as a
dependency" is, at best, hard to understand (personally I didn't
understand it).

Instead of this abstract paragraph, why don't you _SHOW_ the change that
you made, by repeating the above example with the change you tried, then
_showing_ the result you got, and stating specifically exactly what you
wanted to get instead?

We can't deal with a 200-line makefile embedded in a question, but a few
10-15 line example makefiles along with specific example output and
details on what was expected are much easier for us to understand and
comment on than a written description that requires us to make a lot of
guesses about what you're actually doing.

Cheers!