Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!bloom-beacon!eru!hagbard!sunic!liuida!isy!herkules.sssab.se!sveer
From: sveer@sssab.se (Sven L Eriksson)
Newsgroups: comp.unix.programmer
Subject: How common is :: in makefiles
Message-ID: <8nvggoksuC@herkules.sssab.se>
Date: 20 Feb 91 16:44:29 GMT
Organization: Hackers Unlimited
Lines: 34

The X11 makefiles (produced by Imakefile) uses a feature that isn't
documented in my system (Sys V.3.2) although it works.
They use a double : instead of a single in the dependency rules.
This allows several rules with the same name. The effect is that
all these rules are executed. If a makefile contains:

foo ::
	@echo making foo

bar ::
	@echo making bar

foo ::
	@echo making more foo

then "make foo" will produce

making foo
making more foo

If single : are used instead make will complain.

Is this a general undocumented feature of make?
X11 is portable to a lot of platforms so I guess they have
thought about this. But do make on all systems have it?
Dare I use it in makefiles that are going to be ported to many
different systems.

Thanks for any responses. / Sven
-- 
- Sven L Eriksson, 3S AB (Scandinavian System Support AB)    o O___ _________
- Address: Agatan 4, Box 535, S-581 05 Linkoping, Sweden   _][__|o| |O O O O|
- Phone: +46-13-11 16 60    Fax: +46-13-11 51 93          <_______|-|_______|
- Email: sveer@sssab.se     UUCP: uunet!sunic!sssab!sveer  /O-O-O     o   o