Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!snorkelwacker!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: Unsigned long question
Message-ID: <17296@haddock.ima.isc.com>
Date: 8 Aug 90 22:43:00 GMT
References: <5631@uwm.edu>
Reply-To: karl@kelp.ima.isc.com (Karl Heuer)
Distribution: usa
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 24

In article <5631@uwm.edu> peter@csd4.csd.uwm.edu (Peter J Diaz de Leon) writes:
>When reg1 is an unsigned int mode prints out correctly.
>When reg1 is an unsigned long int [it fails].

>	test(reg1, mode) unsigned long reg1; int mode; {
>	    printf("TEST: mode=0x%x \n", mode);
>	}
>	... test(0x1, ME);

The formal parameter has type `unsigned long int', but the actual argument
`0x1' has type `int'.  If you have lint, it should have flagged the mismatch.

The portable fix is to use an explicit cast:
	... test((unsigned long int)0x1, ME);
If you're only interested in ANSI C compilers, then you could use a typed
constant
	... test(0x1UL, ME);
or make sure there's a prototype in scope when test() is called:
	test(unsigned long reg1, int mode) {
	    printf("TEST: mode=0x%x \n", mode);
	}
	... test(0x1, ME);

Karl W. Z. Heuer (karl@kelp.ima.isc.com or ima!kelp!karl), The Walking Lint