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From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c++
Subject: Re: Mixing C with C++
Message-ID: <691@taumet.com>
Date: 25 Apr 91 14:50:02 GMT
References: <1991Apr22.064847.16929@cs.nott.ac.uk> <1991Apr23.133931.6716@ssd.kodak.com> <690@taumet.com>
Organization: Taumetric Corporation, San Diego
Lines: 29

steve@taumet.com (Stephen Clamage) writes:

>You write the actual main() in its own module like this:
>	extern int my_main(int, char**);
>	main(int argc, char** argv)
>	{
>	    return my_main(argc, argv);
>	}
>Compile it with the C++ compiler, and put it in your library.  Instruct
>your users to write their main() with the name "my_main" instead.
>Everything should just work.

Oops!  I forgot two very important points.

1.  Unless you supply the C++ runtime library and any special startup
modules (some systems provide a replacement crt0.o or equivalent),
or you will have to pre-link your entire library with the C++ runtimes
and supply it as a single object module.  Otherwise, things may turn
up missing when a user tries to link a program.

2.  Most C++ implementations require steps to be done after linking.
(Cfront requires "patch" or "munch", Oregon C++ requires "cdlink".)
Any application with static objects requiring constructors or
destructors (such as stream I/O) will require this step.  You will have to
experiment to see if the step can be omitted when there are no static
objects.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com