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From: mouse@mcgill-vision.UUCP (der Mouse)
Newsgroups: net.unix-wizards
Subject: Re: linking C and Fortran
Message-ID: <481@mcgill-vision.UUCP>
Date: Wed, 13-Aug-86 22:38:46 EDT
Article-I.D.: mcgill-v.481
Posted: Wed Aug 13 22:38:46 1986
Date-Received: Tue, 19-Aug-86 22:16:56 EDT
References: <2668@brl-smoke.ARPA>
Organization: McGill University, Montreal
Lines: 32
Summary: C foo -> _foo, f77 foo -> _foo_

In article <2668@brl-smoke.ARPA>, moss@BRL.ARPA (Gary S. Moss (SLCBR-VLD-V)) writes:
> 	CC prepends an underscore to the function name, and F77 appends
> an underscore.  [Explanation, basically that f77 _forsub <-> C forsub_]

Well, I don't know what system you're on, but on all UNIX f77s I know
of, f77 appends an underscore and hands the result to the C compiler,
at least conceptually.  The result is that C ultimately prepends an
underscore and f77 *both* appends *and* prepends underscores.  The net
result is that what f77 knows as "forsub" is what C knows as "forsub_".

> Be sure to define/invoke the function from C with pointers (call by
> reference) exclusively.

Good point.  Also make sure the pointers point to something!  Probably
the commonest problem I see with pointers here is

	something *ptr;
	routine(ptr);

because they've been told that "routine" takes a "pointer to something"
as its argument.  They never notice that this pointer has to point to
a "something".
-- 
					der Mouse

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