dynamic code compilation

Question

I'm working on a program that renders iterated fractal systems. I wanted to add the functionality where someone could define their own iteration process, and compile that code so that it would run efficiently.

I currently don't know how to do this and would like tips on what to read to learn how to do this.

The main program is written in C++ and I'm familiar with C++. In fact given most of the scenarios I know how to convert it to assembly code that would accomplish the goal, but I don't know how to take the extra step to convert it to machine code. If possible I'd like to dynamically compile the code like how I believe many game system emulators work.

If it is unclear what I'm asking, tell me so I can clarify.

Thanks!

Answer 1

Does the routine to be compiled dynamically need to be in any particular language. If the answer to that question is "Yes, it must be C++" you're probably out of luck. C++ is about the worst possible choice for online recompilation.

Is the dynamic portion of your application (the fractal iterator routine) a major CPU bottleneck? If you can afford using a language that isn't compiled, you can probably save yourself an awful lot of trouble. Lua and JavaScript are both heavily optimized interpreted languages that only run a few times slower than native, compiled code.

If you really need the dynamic functionality to be compiled to machine code, your best bet is probably going to be using clang/llvm. clang is the C/Objective-C front end being developed by Apple (and a few others) to make online, dynamic recompilation perform well. llvm is the backend clang uses to translate from a portable bytecode to native machine code. Be advised that clang does not currently support much of C++, since that's such a difficult language to get right.