Re: GNUMAKEFLAGS vs MAKEFLAGS

[Paul Smith]

On Tue, 2024-07-16 at 20:27 +0200, Alejandro Colomar wrote:
> As discussed in a different thread, the docs claim that GNUMAKEFLAGS
> and
> MAKEFLAGS are treated in the same way.
> 
> All else equal, since I'm using GNU-specific flags, I think I should
> be
> using GNUMAKEFLAGS.
> 
> However, Paul said that I should use MAKEFLAGS, because GNUMAKEFLAGS
> is not special when passing -R and/or -r.

That's not actually what I said.

What I said was that GNUMAKEFLAGS is not special when it appears inside
a makefile.  It's only special when it's read from the environment.

That is, this does what you expect:

  $ GNUMAKEFLAGS=-Rr make -f Makefile

but this doesn't do what you expect:

  $ cat Makefile.pre
  GNUMAKEFLAGS += -Rr

  $ make -f Makefile.pre -f Makefile

> Should make(1) be patched to actually treat GNUMAKEFLAGS the same as
> MAKEFLAGS?
> 
> Or maybe should the docs be fixed to say that GNUMAKEFLAGS doesn't
> have the special properties that MAKEFLAGS has?

I think it will be difficult to change make to treat GNUMAKEFLAGS as
special inside a makefile.  The entire handling of makefiles is a
hornets nest, and we are stung repeatedly every time we try to tweak it
to work differently.

And, I'm not convinced such a thing is really useful.  If you are
writing a makefile and you are relying on this always being set, it's
almost 100% guaranteed that your makefile won't work with any other
version o make anyway.

So I'm not sure I see the harm in having people write:

   MAKEFLAGS += -rR

inside their makefiles, if that's the behavior they want.