Re: MAKECMDGOALS

[Sébastien Hinderer]

Dear Paul,

Many thanks for your response.

I was not trying to debate :)

It seems I used "defined" where youu use "set" but that's what I meant.
Shouldn't make set this variable to theempty string rather than not
setting it at all?

Cheers,

Sébastien.




Paul Smith (2021/02/01 09:17 -0500):
> On Mon, 2021-02-01 at 11:49 +0100, Sébastien Hinderer wrote:
> >    'Make' will set the special variable 'MAKECMDGOALS' to the list of
> >    goals you specified on the command line.  If no goals were given on
> >    the command line, this variable is empty.
> >
> > If I define the following Makefile:
> >
> > ifeq "$(MAKECMDGOALS)" ""
> >
> > make --warn-undefined-variables
> >
> > Makefile:1: warning: undefined variable 'MAKECMDGOALS'
> >
> > Am I correct that there is a mismatch between make's documented and
> > real behaviour?
>
> Hm.  Well, I could use a language lawyer's response and say that "this
> variable is empty" is not the same thing as "this variable is set to
> the empty value".
>
> The variable _IS_ empty, in the same way that any unset variable is
> empty.
>
> If you want to tell the difference between a variable that is not set
> at all versus set to the empty string, you have to use the
> $(origin ...) function.
>
> Instead of your code you could use:
>
>     MAKECMDGOALS ?= default
>
> which will set MAKECMDGOALS IFF it has never been set at all (not even
> to the empty string).
>
> Probably this section of the documentation should be updated to be more
> clear so that reading it doesn't require language lawyering.
>