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From: mcbain@latcs1.oz (Mike McBain)
Newsgroups: comp.sources.bugs,comp.sources.d
Subject: C program database source - bugfix
Message-ID: <3615@latcs1.oz>
Date: Sun, 4-Oct-87 22:52:34 EDT
Article-I.D.: latcs1.3615
Posted: Sun Oct  4 22:52:34 1987
Date-Received: Fri, 9-Oct-87 01:05:15 EDT
Organization: Comp Sci, La Trobe Uni, Australia
Lines: 34
Keywords: pointers to functions
Xref: mnetor comp.sources.bugs:349 comp.sources.d:1335


The recent posting of the C source database system looks like a really
useful piece of software. While there seem to be some traps for
the unwary SysV user associated with dir.h vs ndir.h, there is a
portability and/or reality problem with at least one line in lid.c.

In that file occurs the following line:

                if ((doit == lookId && !forceMerge).....

The problem with this expression is that doit is a pointer and lookId is
a pointer to function. Why is this a problem?  Because K&R do not actually
state whether or not a function has an address that can be pointed to.
So my compiler (on a National Semiconductor 3216) comes up with the 
'incompatible arguments'.  This problem can be solved with the following
cast expression;


		if ((doit == (void(*)())lookId && !forceMerge)

which should work for everyone. This may be an obscurity, but is also
part of both the pleasure and the pain of a language like C


Mike McBain,			ISD:	+61 3 479-2393
Department of Computer Science,	STD:	(03) 479-2393
La Trobe University,		ACSnet:	mcbain@latcs1.oz
Bundoora,			CSnet:	mcbain@latcs1.oz
Victoria, 3083,			ARPA:	mcbain%latcs1.oz@uunet.uu.net
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