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From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.unix.questions,comp.unix.wizards,comp.lang.c
Subject: Re: _why_ does the UNIX linker not distinguish text and data addresses???
Message-ID: <365@taumet.com>
Date: 31 Jul 90 16:25:17 GMT
References: <1990Jul30.104726.22660@mtcchi.uucp>
Followup-To: comp.unix.questions
Distribution: na
Organization: Taumetric Corporation, San Diego
Lines: 27

levy@mtcchi.uucp (Daniel R. Levy) writes:

|::::::::::::::
|a.c
|::::::::::::::
|main()
|{
|	(void) bogus();
|}

|::::::::::::::
|b.c
|::::::::::::::
|int bogus;

Traditional Unix object-file formats, and thus the linkers, are very
simple-minded.  They certainly could distinguish between text and
data addresses, but simply don't.  It is up to the programmer, even
in ANSI C, to take care that extern declarations/definitions in separate
compilation units match.  Lint will generally pick up mismatches.

In C++, BTW, this example will fail at link time no matter what linker
is used, since the type of the function is encoded by the compiler into
its true external name.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com