Intermixing C / C++ code

lucky6969b · 12-30-2005, 03:10 AM

Is it possible?
I have certain aspects of my programs that are favourably to be written in C, while the large part is still C++...
I know I have to take care of data mangling. What other aspe cts do I need to look after?
Thx
Jack

scuzzman · 12-30-2005, 04:53 AM

All valid C programs are valid C++ programs. So long as you load the proper libraries, you should be able to intermix the code with no problems.

vivekr · 12-30-2005, 05:24 AM

I have heard function name mangling in C++.
It involves renaming overloaded fns to identify them and that too will be done by the compiler(even for normal fns).(So what is data mangling?)

To overcome this use extern "C" prefix before functions.

Apart from this to my knowledge there isn't any mangling stuff.
And as scuzzman said almost all C programs are C++ progs.
I cant understand what u mean by a C/C++ design

ta0kira · 12-31-2005, 04:00 AM

If you #include your C into a C++ file to compile then your C will get mangled. There are 2 ways around this:

1) Keep your C in separate files, compile them as C into .o files, then make .o files from your C++, and then link them together

2) Put the things you don't wan't mangled into this:

Code:

extern "C"
{
        //C is safe here!
}

That second way you can even put some of your C++ declarations in there, then define them outside of it using C++:

Code:

extern "C"
{
        void *getHandle();
        //Can only do C here...
}

void *getHandle()
{
        //But I can put C++ in the definition here!
}

By the way, name mangling only really matters if you are building a shared library or something that you will link to from other programs. If you don't do that, you don't really have to worry about it; even though g++ mangles C++ names, it's consistent, so it knows what all the mangled names are supposed to be.
ta0kira

primo · 12-31-2005, 08:06 PM

Yes, and to make them compile safer in both C++ & C compilers you may use:

Code:

#if defined(__cplusplus)
extern "C" {
#endif

/* stuff */

#if defined(__cplusplus)
}
#endif