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From: wagner@iaoobelix.UUCP
Newsgroups: comp.lang.c
Subject: Re: Strange C-compiler message ... - (nf)
Message-ID: <6700009@iaoobelix.UUCP>
Date: Fri, 8-May-87 07:22:00 EDT
Article-I.D.: iaoobeli.6700009
Posted: Fri May  8 07:22:00 1987
Date-Received: Sun, 10-May-87 05:41:29 EDT
References: <214@cjsa.UUCP>
Lines: 28
Nf-ID: #R:cjsa:-21400:iaoobelix:6700009:000:911
Nf-From: iaoobelix!wagner    May  8 12:22:00 1987

> /***** iaoobelix:comp.lang.c / cjsa!jeff /  3:11 pm  May  5, 1987*/
> I got a strange message while compiling a routine the other day and was
> wondering if anyone could explain its meaning.
...
> The compiler ran for a time and then the following message was generates:
> 
> 	$! nulled, predecessor circle
> 

The message you got has nothing to do with the compiler. It comes from 'make'.
Try the following: write a file `Makefile' containing

	foo:	foo
		@echo this is foo.

Then say `make'. You will get something like

	% make
	$! nulled, predecessor circle
	this is foo.
	%

What I want to show is that you Makefile contains a cyclic reference (a file
depends on itself, and is non-existent). The cyclic reference is ignored
automatically ("nulled"), so the respective action is performed.

Juergen Wagner,		     (USENET) ...seismo!unido!iaoobel!wagner
("Gandalf")			 Fraunhofer Institute IAO, Stuttgart