[m-dev.] for review: fix undefined variable warnings

[Tyson Dowd]

On 29-Jul-1998, Fergus Henderson <fjh at cs.mu.OZ.AU> wrote:
> Hi,
> 
> Anyone care to review this one?

Yeah, I'll tackle it.

> 
> --------------------
> 
> Add Mmake support for target-specific MCFLAGS flags (MCFLAGS-foo, etc.)
> using some tricky GNU Make hackery that avoids warning about undefined
> variables.
> Also define ALL_MCFLAGS = $(MCFLAGS) $(TARGET_MCFLAGS) $(EXTRA_MCFLAGS)
> and use $(ALL_MCFLAGS) instead of $(MCFLAGS).  This allows user Mmakefiles
> to override MCFLAGS without suppressing the use of the TARGET_MCFLAGS
> and EXTRA_MCFLAGS.
> 
> Similarly for the other *FLAGS variables. 
> 
> scripts/Mmake.vars.in:
> 	Define ALL_*FLAGS and TARGET_*FLAGS.
> 
> scripts/Mmake.rules:
> 	Use ALL_*FLAGS instead of *FLAGS.
> 
> scripts/mmake.in:
> 	Re-enable the warnings about undefined variables,
> 	since we won't get too many spurious warnings now.
> 	
> Mmake.common.in:
> 	Delete `$(MCFLAGS-$*)' from the definition of `MCFLAGS', since this
> 	is now done automatically by Mmake.
> 
> tests/Mmake.common:
> 	Delete the definitions of MCFLAGS and GRADEFLAGS, since this stuff
> 	is now done automatically by Mmake.

The change seems fine.  It might be worthwhile documenting this
feature in both NEWS and doc/user_guide.texi.

Tyson.