Re: [PATCH 01/11] doc: allow the user to provide ASCIIDOC_EXTRA

[Felipe Contreras <felipe.contreras@gmail.com>]

Jeff King wrote:
> On Sat, May 15, 2021 at 07:13:48AM -0500, Felipe Contreras wrote:
> > Jeff King wrote:

> > > To go into further detail: usually we distinguish variables we use
> > > internally from user-facing ones, and include the latter in the former.
> > > I see a later patch wants to start passing ASCIIDOC_EXTRA on the
> > > command-line, and we'd use two variables for that.
> > 
> > Well, it's not exactly user-facing; it's only needed for doc-diff.
> 
> It's meant for the caller of "make". Your proposed use is within
> doc-diff, but any user running "make ASCIIDOC_EXTRA=foo" would see the
> different behavior.

Yeah, they would, but I don't think it would be wrong behavior.

> > Would TEST_ASCIIDOC_EXTRA make sense?
> 
> I'd probably call it ASCIIDOC_FLAGS (like we have CFLAGS and LDFLAGS
> that are meant for users to inform us of extra flags they'd like
> passed).

Right, but Makefiles do override those, like:

  override CFLAGS += -fPIC

Otherwise builds may fail.

> Of course that may not solve your problem in a sense; if you want
> doc-diff to override it, then that might conflict with a theoretical
> ASCIIDOC_FLAGS somebody set in their config.mak (but we really are in
> the realm of hypothetical here).

Setting ASCIIDOC_FLAGS in config.mk would not override the
user-supplied flags any more than setting them in the Makefile (they are
virtually the same thing as one includes the other).

It's only if the user has `override ASCIIDOC_FLAGS` in config.mk that
such a problem would arise. And that's really hypothetical.

Cheers.

-- 
Felipe Contreras