Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!ulysses!allegra!princeton!udel!gatech!hao!noao!mcdsun!sunburn!gtx!al
From: al@gtx.UUCP
Newsgroups: comp.lang.c
Subject: functions defaulting to int
Message-ID: <528@gtx.com>
Date: 15 Jan 88 21:59:10 GMT
Reply-To: al@gtx.UUCP (Al Filipski)
Organization: GTX Corporation, Phoenix
Lines: 41
Posted: Fri Jan 15 16:59:10 1988

To illustrate a point about C, I had occasion to write the following 
toy program: 

#include <stdio.h> 
main()
{
   int (*x)();
   x = printf;
   (*x)("Hello, world\n");
}

and was slightly irritated when cc (one on SV, one on BSD4.2) choked,
saying "line 5: printf undefined".  Neither the stdio.h on my AT&T 7300,
nor the one on the SUN has

int printf();

in it.  This is one reason (maybe not an earth-shaking one, though) why
the standard header files SHOULD contain declarations even for int
procedures.  I expect more will when ANSI C compilers come along
because of the additional information in the prototypes. (Are
declarations for library functions required by the standard?  where
will the system call declarations go?)

mount /dev/soapbox .
In my opinion, one of the main design flaws in  C is the rule that
makes procedures int by default.  We had some vax code that called
malloc() but didn't include malloc.h.  Works fine on the vax, but on
the M68000, malloc puts its return value (an address) in a0, then the
calling program picks up the "int" it expects from d0, and the fun
begins.  Lint really pays for itself on occasions like this.
umount /dev/soapbox

    ----------------------------------------------------------------------
   | Alan Filipski, GTX Corp, 2501 W. Dunlap, Phoenix, Arizona 85021, USA |
   | {ihnp4,cbosgd,decvax,hplabs,seismo}!sun!sunburn!gtx!al (602)870-1696 |
    ----------------------------------------------------------------------
I wanted to put the quotation from Shakespeare about the "sea change"
here, substituting "C" for "sea", but couldn't remember how it goes.
Since looking something up would violate some Usenet rule, just pretend
it's here.