Path: utzoo!utgpu!watserv1!watmath!att!rutgers!uwm.edu!rpi!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!uflorida!haven!mimsy!chris
From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: Nasty bug
Message-ID: <26328@mimsy.umd.edu>
Date: 1 Sep 90 20:43:59 GMT
References: <0093BF08.7F3834E0@rigel.efd.lth.se> <7330028@hpcllca.HP.COM>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 28

In article <7330028@hpcllca.HP.COM> walter@hpcllca.HP.COM (Walter Murray)
writes:
>You got bit by what is called type rewriting [in which a C compiler
changes the type of a formal parameter declaration to match the type
of any actual parameter passed by any caller, i.e., the compiler applies
type-widening rules].

>Type rewriting is not permitted for a compiler that conforms to the
>ANSI standard. ...

... except in the case of formal array parameters, where it is required:

	f(x) int x[]; { ... /* sizeof(x) == sizeof(int *) */

is the same as

	f(x) int *x; { ... /* sizeof(x) == sizeof(int *) */

and in fact the compiler is Officially Obliged to forget% that x was
declared with empty square brackets rather than an asterisk.  The
situation is unchanged when prototype definitions are used.

-----
% Well, modulo things not covered by the standard, such as program
  listings, error messages, and warnings.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 405 2750)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris