Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!purdue!ames!xanth!kremer
From: kremer@cs.odu.edu (Lloyd Kremer)
Newsgroups: comp.lang.c
Subject: Re: Prototyping char parameters in ANSI C
Summary: aren't there NEW rules about this?
Message-ID: <8661@xanth.cs.odu.edu>
Date: 27 Apr 89 15:35:46 GMT
References: <3950014@eecs.nwu.edu>
Organization: Old Dominion University, Norfolk, Va.
Lines: 39


In article <3950014@eecs.nwu.edu> gore@eecs.nwu.edu (Jacob Gore) writes:

>Is this valid ANSI C (or dpANS or whatever you want to call it):
>
>	void f(char);
>
>	void f(c)
>	   char c;
>	{
>	}
>
>The version of GNU cc I have complains:
>
>	t.c: In function f:
>	t.c:5: argument `c' doesn't match function prototype
>	t.c:5: a formal parameter type that promotes to `int'
>	t.c:5: can match only `int' in the prototype


The responses I have seen all make reference to "old style" automatic widening
of the function argument to an int.  The fact that the original poster
specified ANSI C suggests that he knows about the "old style" rules.

In any case I know I do.  :-)  But I thought that in the new ANSI C (not old--
NEW!) you could effectively circumvent this behavior and request that small
types be received by the called function as a true char (or float, or
whatever), size and all.  There may still be temporary internal promotion due
to hardware characteristics such as the inability to push a single byte onto
the stack, but this should be transparent to the programmer.

So, I shall now ask: How do you tell the compiler that you want this *NEW*
behavior?  If a full prototype isn't good enough, what is?

-- 
					Lloyd Kremer
					Brooks Financial Systems
					...!uunet!xanth!brooks!lloyd
					Have terminal...will hack!