Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!udel!rochester!kodak!ispd-newsserver!ism.isc.com!redwood.sos.ivy.isc.com!billri
From: billri@redwood.sos.ivy.isc.com (Bill Rizzi)
Newsgroups: comp.lang.c++
Subject: Re: SUMMARY:  C and C++
Keywords: C++ static object construction
Message-ID: <1991Apr04.195944.17095@ism.isc.com>
Date: 4 Apr 91 19:59:44 GMT
References: <1991Apr3.011032.14110@terminator.cc.umich.edu> <1990@godzilla.tcs.com>
Sender: usenet@ism.isc.com (Ism Usenet News)
Reply-To: billri@ivy.isc.com
Organization: Interactive Systems Corp.
Lines: 41

In article <1990@godzilla.tcs.com>, gwu@nujoizey.tcs.com (George Wu) writes:
|> In article <1991Apr3.011032.14110@terminator.cc.umich.edu>,
|> normanb@pinhead.citi.umich.edu (David R. Richardson) writes:
|> |> Last week I asked this newsgroup for comments on combining C and
|> |> C++.  Here is a summary of replies:
|> |> 
|> |> [ . . . stuff deleted . . . ]
|> |> 
|> |> For example, cfront performs this initialization by calling a routine,
|> |> "_main()".  In translating your C++ code, cfront places a call to this
|> |> routine right after YOUR main().
|> 
|>      Correction: _main() is called *before* my/your main().  And to be
|> entirely complete, cleanup code (destructors for static and global objects)
|> need to be called when main() is finished.

	Actually, cfront (AT&T C++ 2.1) places the call to _main() as the
first statement in the definition of C function main().  Just take a peek at
the generated C code.  You'll see something like:

... main(...) { _main();
...
}

	I don't know for sure that _main() is standard with all C++
compilers, however.

	Regarding destructors, the C++ library has an exit() function which
takes care of this.  So as you pointed out, it is important to link with the
C++ libraries.	If your main() function is in C, an (early) call to _main() is
indeed appropriate.  It is probably also a good idea to call exit() explicitly,
rather than "falling off" the end of your main() function and relying on the C
runtime to call exit().


	Bill

-- 
Bill Rizzi		INTERACTIVE Systems Corporation
billri@ivy.isc.com	26635 W. Agoura Rd, Suite 200
818-880-1200 x2110	Calabasas, CA  91302