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Re: Using GCC-java as a scripting language on top of C++ - possible?


On Oct 19, 2003, at 11:40 AM, Asfand Yar Qazi wrote:

I want to use gcj as a scripting language on top of a c++-written engine: is this possible?

I don't know what you mean by "scripting language", but if you mean putting a Java wrapper around some existing C++ classes, then yes, sure!


Assuming the ABIs are compatible, I'm assuming I just need to find a way to generate java source files from C++ header files, and I'll be able to use the C++ classes as normal java classes (for simple things, anyway - no deriving, probably.)
I'm prepared to write java interfaces for the C++ classes manually, if necessary.

You can't generate a Java interface automatically from C++ headers. The ABIs for C++ and Java are compatible such that code in each of the two languages can interoperate, but you can't call a non-Java C++ class directly from Java. For one thing, not all C++ types are available in Java.


The way to do this is to define an interface into your native code in terms of "native" methods in a Java class, then implement those methods in C++ such that they wrap your C++ classes.

Basically, with CNI, Java classes can be used as if they were C++ classes - but not vice-versa!

Regards,

Bryce.


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