Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!brl-adm!brl-smoke!gwyn From: gwyn@brl-smoke.ARPA (Doug Gwyn ) Newsgroups: comp.lang.c Subject: Re: Why static forward references Message-ID: <5478@brl-smoke.ARPA> Date: Mon, 5-Jan-87 14:12:23 EST Article-I.D.: brl-smok.5478 Posted: Mon Jan 5 14:12:23 1987 Date-Received: Mon, 5-Jan-87 22:00:04 EST References: <6927@ki4pv.UUCP> <4870@mimsy.UUCP> Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB)) Organization: Ballistic Research Lab (BRL), APG, MD. Lines: 26 In article <4870@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes: >In article <6927@ki4pv.UUCP> tanner@ki4pv.UUCP (Tanner Andrews) writes: >>extern char *blunge(); /* declare blunge */ >>char *gork() { return(blunge(69)); } /* use blunge */ >>static char *blunge(arg) int arg; { /* body of blunge here */ } >But if the ANSI standard mandates that the code author must use >`extern' or `static' on forward declarations, these compiler writers >can save themselves the trouble of doing things right, or of fixing >their linkers. And that appears to be the entire motivation. I don't think that is the issue at all. The question is, WHICH "blunge" should be used in the above example? There might be an external blunge() function also. According to the "declare things correctly before you use them" school, the external blunge() should be used, not the internal one. The one-pass compilation model also requires this, since the meaning of the reference to blunge() cannot depend on goings-on lexically later in the source file. This becomes even more significant when one considers the fact that the rules for internal and external symbol names (case folding, truncation, etc.) may well differ. P.S. "extern" is not required for such function declarations, forward reference or no, since a function declaration with neither "extern" nor "static" is taken to have external linkage if linkage hasn't already been determined by a previous declaration.