Date:	Tue, 23 Apr 1996 21:44:43 -0800 (GMT)
From:	"Rafael R. Sevilla" <rsevilla AT upd DOT edu DOT ph>
To:	actainc AT cerf DOT net, djgpp AT delorie DOT com
Subject:	Re: YACC and BISON
Message-ID:	<Pine.SOL.3.91.960423213007.29538B-100000@sauron>
MIME-Version:	1.0

Yeah, I know what it's like. That was my first (and only) problem in
porting my grammar to Bison from Yacc. I had to get the mv port from the
GNU fileutils (which Eli kindly suggested), because for some inexplicable
reason the built-in make for .y files expects to find a mv command! Which
of course does not normally exist in DOS.

The only serious solution which finally got rid of all this foolishness 
was not to use the default rules for .y files and move, er, rename them 
yourself explicitly. The update utility which came with djgpp helps a 
great deal. The makefile would thus look like this:

y_tab.c: grammar.y $(INCLUDES)
	bison -y -d grammar.y

grammar.h:	y_tab.c
	update y_tab.h grammar.h

grammar.c:	y_tab.c
	rename y_tab.c grammar.c

This saves recompilation for whatever files might need grammar.h, because 
update only updates grammar.h if y_tab.h is really different from the old 
grammar.h. Normally, that file doesn't change much, right?

That is my pet peeve with these djgpp programs--their lineage from Unix 
is so explicit that they sometimes fall down when we get to the 
differences between the two operating systems, the pathetic DOS 8.3 
filename limit is only one of them.

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University of the Philippines                           Rafael R. Sevilla
PABX/OVCA: Diliman Networking Project          rsevilla AT sauron DOT upd DOT edu DOT ph
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