Message-ID: <3887A562.12D15B9A@connection.com>
Date: Thu, 20 Jan 2000 19:16:37 -0500
From: sam <samirw AT connection DOT com>
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Subject: Re: libraries headaches
References: <388637B2 DOT 333A30C6 AT connection DOT com> <8671ho$co6$1 AT nets3 DOT rz DOT RWTH-Aachen DOT DE>
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To: djgpp AT delorie DOT com
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Hans-Bernhard Broeker wrote:

> sam <samirw AT connection DOT com> wrote:
> [...]
> > So who can tell me how to name my functions so that I can write C++ code
> > and libraries.
>
> Your problem, most probably, is not with C++ itself, or the names of
> your functions. It's with *mixing* C and C++ parts (C library, C++
> main program) in the same program.
>

Actually, I had both compiled as C++ but when it didn't work I have changed
the main program to 'C'. Now that I think about it there is no sense to have
libraries in C++ if most of the program is not. Shouldn't even be possible.

>
> > I have stumbled across the term 'name mangling'???
>
> That's exactly your problem, I suspect. C++ adds information to the
> names of objects (variables, functions) to carry type information, for
> things like polymorphism, i.e. a function
>
>         int dosomething(double arg1, char *arg2);
>
> may become the following linker-visible symbol:
>
>         .globl dosomething__FdPc
>
> C doesn't do that, so the same function would be compiled to
>
>         .globl dosomething_
>
> and that's it. To avoid this, you have to *tell* the C++ compiler that
> an external function declaration (prototype in a header) is for a
> C, not a C++ function.
>
>         extern "C" {
>          /* C declarations here */
>         }
>

So that's what that is for.

>
> does that for you. Read up the details in Stroustrup or some other C++
> textbook.
>
> --
> Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
> Even if all the snow were burnt, ashes would remain.

Thank you for your time.