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From: torek@elf.ee.lbl.gov (Chris Torek)
Newsgroups: comp.unix.programmer
Subject: Re: Make doesn't understand .SUFFIXES: .b .c .s .i .o
Message-ID: <13951@dog.ee.lbl.gov>
Date: 5 Jun 91 16:25:02 GMT
References: <23182@shlump.lkg.dec.com>
Reply-To: torek@elf.ee.lbl.gov (Chris Torek)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 21
X-Local-Date: Wed, 5 Jun 91 09:25:02 PDT

In article <23182@shlump.lkg.dec.com> jc@netrix.nac.dec.com writes:
>If I tell [make] to make foo.c, it works, and then it knows how to make
>foo.o from foo.c; the problem is that it doesn't seem to understand
>the .b -> .c -> .o sequence ...

This kind of thing---taking the b->c and c->o sequence and deriving
the b->o sequence from that---is called `transitive closure'.

Most `make' programs do not do transitive closure.

What you must do, then, is define not only a b->c rule and a c->o rule
but also a b->o rule.

>What I've been doing is adding lines to the makefile like:
> foo.c:  foo.b
>and then it works fine.

Right: because this adds an implicit rule via an explicit dependency.
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 415 486 5427)
Berkeley, CA		Domain:	torek@ee.lbl.gov