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From: minow@mountn.dec.com (Martin Minow)
Newsgroups: comp.lang.c,comp.std.c
Subject: Re: Protoize/Unprotoize (was: ANSI C to K&R syntax converter)
Summary: Why bother writing a tool?
Message-ID: <1645@mountn.dec.com>
Date: 4 Jun 90 18:57:05 GMT
References: <1990May31.214655.18960@csrd.uiuc.edu> <26699454.10047@paris.ics.uci.edu>
Reply-To: minow@thundr.enet.dec.com (Martin Minow)
Followup-To: comp.lang.c
Organization: Digital Equipment Corporation
Lines: 44

In article <1990May31.214655.18960@csrd.uiuc.edu> pommerel@sp14.csrd.uiuc.edu
(Claude Pommerell) writes:
>
>I am looking for a portable converter from ANSI C syntax to
>traditional Kernighan&Ritchie syntax.

I've had good results by writing prototypes using the following process:

	/*
	 * prototype.h
	 */
	#ifdef _STDC_
	#if _STDC_ != 0
	#define _(x)	x
	#endif
	#endif
	#ifndef _STDC_
	#define _(x)	()
	#endif

	/*
	 * All functions are specified here:
	 */
	int		sample _((int, char *, struct foo));

The actual definition of a function uses the old -- but still valid -- syntax:

	int
	sample(i, cp, foostruct)
	int		i;
	char		*cp;
	struct foo	foostruct;
	...

The advantage is that your code remains maximally portable, yet you have
the advantage of type-safety where available.  The disadvantage is that
you *must* not presuppose other Ansi features, such as automatic conversion
of variables.  Also, the above doesn't handle variable-length argument lists.
(Also, strictly speaking, the macro '_' is reserved to the implementation).

The above should be portable to all C implementations since around 1978.

Martin Minow
minow@thundr.enet.dec.com