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From: levy@ttrdc.UUCP
Newsgroups: mod.computers.vax
Subject: (none)
Message-ID: <8606170258.AA13691@ucbvax.Berkeley.EDU>
Date: Mon, 16-Jun-86 22:58:23 EDT
Article-I.D.: ucbvax.8606170258.AA13691
Posted: Mon Jun 16 22:58:23 1986
Date-Received: Thu, 19-Jun-86 07:45:05 EDT
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Subject: Re: Important change to VMS C v2.2 with VMS v4.4
In-reply-to: your article <8606140748.AA14243@ucbvax.Berkeley.EDU>

In article <8606140748.AA14243@ucbvax.Berkeley.EDU>, LEICHTER-JERRY@YALE.ARPA writes:
>The use of this "first function will be transfer address" feature should
>probably be avoided - it's non-portable (though I'd guess it's in VAX C
>exactly because other implementations did this - Unix is one, in fact - and
>programs came to rely on it.
>							-- Jerry
>-------

Don't badmouth UNIX so quickly.  Here's what happens in SysV:

$ cat foo.c
foo()
{
	printf("hello, world!\n");
}
$ cc -o foo foo.c
undefined		first referenced
 symbol  		    in file
main                		/lib/crt0.o
ld fatal: Symbol referencing errors. No output written to foo

The interpretation of this is that the UNIX linker was looking for a main()
to satisfy the reference by the startup routines contained in the object
module /lib/crt0.o (there is a _start() routine in /lib/crt0.o which the
linker treats as a hardwired "transfer address" and which calls main()).
The linker did not find main() so it barfed.  Simple, no?
--
 -------------------------------    Disclaimer:  The views contained herein are
|       dan levy | yvel nad      |  my own and are not at all those of my em-
|         an engihacker @        |  ployer or the administrator of any computer
| at&t computer systems division |  upon which I may hack.
|        skokie, illinois        |
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