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Re: Incompatible change in rules.make as of v1.149

From: Nicola Pero
Subject: Re: Incompatible change in rules.make as of v1.149
Date: Tue, 22 Apr 2003 16:46:03 +0100 (BST)

> > Interesting.
> >
> > :-)
> >
> > The rule you need is probably something like -
> >
> > %.c: %.y
> >     $(YACC) $(YACC_FLAGS) $<
> >     mv -f $@
> Hi Nicola,
> just found out that I forgot to ask a question, but anyways, your rule 
> directly leads to it. ;-)
> Why not use a rule such as:
> %.c: %.y
>       $(BISON) $(BISON_FLAGS) -o $@ $<
> The problem here is, I'm not sure which is better. I think that I heard 
> people say that bison usually produces better code than yacc, but I 
> might be wrong. If that would be the case however, then it might 
> possibly be best to decided which rule to use while configuring GNUstep 
> make - if bison is present, take my rule, if not, go with yacc. On the 
> other hand, this might be overkill.

YACC is more portable, which is why it seems more natural as a default
(it's the same default that make itself is using and which was used before
I disabled the built in rules).

If you are on a GNU system, 'yacc' is really just an alias for 'bison -y',
so I'd expect the generated code to be of the same quality no matter if
you use YACC or BISON.

If you want to use BISON because you need/want some special bison features
... then you are probably an enough advanced user that you can overwrite 
the default rule with your own. :-)

Just adding 

%.c: %.y
        $(BISON) $(BISON_FLAGS) -o $@ $<

to your GNUmakefile.postamble will override the gnustep-make %.c:  %.y
YACC-based rule with your own.  It's simple enough.

Configuring gnustep-make to use YACC or BISON doesn't seem a great idea
because some projects might prefer YACC (if targeting portability) while
other projects might prefer BISON (if using special bison features).  It
really depends on the project.

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