Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!killer!tness7!texbell!bigtex!james
From: james@bigtex.uucp (James Van Artsdalen)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Function declarations
Message-ID: <7528@bigtex.uucp>
Date: 4 Sep 88 23:40:30 GMT
References: <10102@genrad.UUCP> <11879@iuvax.cs.indiana.edu> <5680@rpp386.UUCP> <1275@mcgill-vision.UUCP> <13344@mimsy.UUCP> <697@proxftl.UUCP>
Reply-To: james@bigtex.UUCP (James Van Artsdalen)
Organization: F.B.N. Software, Austin TX
Lines: 42

In article <697@proxftl.UUCP>, bill@proxftl.UUCP (T. William Wells) wrote:

> All in the name of easing a few implementers' lives.

> Shame on you X3J11.

> [...] who should have to deal with the pain caused by systems that
> make one pass compilation difficult: every user of ANSI C, or those
> people charged with the writing of a C compiler for those systems?

It's worse than all that.  ANSI C permits conflicting function
declarations without a warning - indeed it is required that no warning
be given.  For example, consider the following in the context of a far
memory model on the 286:

int
a()
{
	int b();

	return b();
}

char *
b()
{
	return "foo";
}

A purely ANSI C compiler must not generate an error according to ANSI
C, because the incorrect declaration of b() is hidden within the scope
of a().  Yet this program cannot work, and I can't conceive of any
implementation where the ANSI C requirement is actually useful.  The
nature of functions in C is such that the *definitions* cannot be
scoped (ie, you can't place a function definition within the scope of
another function as you can in Pascal): it is not clear why it is
desirable that function *declarations* should be subject to scoping.

I too think that the ANSI C committee did a very good job overall.
-- 
James R. Van Artsdalen    ...!uunet!utastro!bigtex!james     "Live Free or Die"
Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746