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From: gdr@eddore.myrias.com (Devin Reade)
Newsgroups: comp.sys.apple2.programmer
Subject: Orca/C v2.1 macro expansion bug
Date: 24 Nov 1996 00:29:07 -0700
Organization: Myrias Research Corporation
Lines: 38
Message-ID: <578tg3$v8@eddore.myrias.com>
NNTP-Posting-Host: eddore.myrias.com

Here's another problem to watch out for.  In well written code it shouldn't
be triggered, but this was in some legacy code I was working on.  I've
already forwarded this to Mike and Soenke.

/*
 * This program demonstrates a problem with macros in Orca/C v2.1.
 *
 * This program incorrectly generates a compilation error because the
 * "ptr" parameter in FUNCTION() is being treated as "char *", as per
 * the typedef in <types.h>.  It _should_ be expanded to the actual
 * parameter first (in this example, "b"), since macro expansion is
 * supposed to occur _before_ tokenizing.
 * (Reference: ISO 9899-1990 art 5.1.1.2.)
 *
 * If "ptr" in the definition of FUNCTION is changed to "d" or some other
 * non-typedef, then this program compiles without error.
 *
 * Reported by Devin Reade <gdr@eddore.myrias.com>, 24 Nov 96.
 */

#pragma lint -1
#pragma debug 25
#pragma keep "ptr"

#include <types.h>
#include <string.h>

#define FUNCTION(c,ptr) strstr(c,ptr)

char *
strstr2 (char *a, char *b)
{
	return FUNCTION(a,b);
}
-- 
The difference between science and the fuzzy subjects is that science
requires reasoning, while those other subjects merely require scholarship.
                                                        - Robert Heinlein