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From: alastair@axis.UUCP (Alastair Adamson)
Newsgroups: net.lang.c
Subject: Re: Proper use of "extern" ...
Message-ID: <712@axis.UUCP>
Date: Mon, 9-Jun-86 11:56:06 EDT
Article-I.D.: axis.712
Posted: Mon Jun  9 11:56:06 1986
Date-Received: Sat, 14-Jun-86 05:55:22 EDT
References: <223@comp.lancs.ac.uk>
Reply-To: alastair@axis.UUCP (Alastair Adamson)
Organization: Axis Digital, 135 rue d'Aguesseau, Boulogne, 92100, FRANCE
Lines: 29
Keywords: extern,static

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In article <223@comp.lancs.ac.uk> david@comp.lancs.ac.uk (David Coffield) writes:
>Suggestions, please, as to the correct use of "extern" ..
>At the top of this file do we put
>a) static void g() 	or
>b) extern void g()?	(extern static must be meaningless).

I would always prefer a) since it helps the reader by making explicit
the fact that the function is local to this file. Further, I like to
declare all extern (other file, library) functions and static functions
before the definition of the first function in a file, after any #includes,
#defines and global variables, as in:

	#include	lines
	#define		lines
	global variables (definitions)
	extern globals   (declarations)
	static functions (declarations)
	extern functions (declarations)
	function definitions

Thus, I would also have said "static void f()" before f()'s definition.

There is a problem with static functions, namely that some C compilers
don't know how to handle them and generate illegal instructions so
that the assembler stage bombs out. You may say that one should avoid
such ridiculous compilers and I would agree with you. Unfortunately,
however, when porting software to other computers one has to put up
with what's available!