[LLVMdev] GCC frontend

[Ramu Ramamurthy]

Chris,

    LLVM is an excellent piece of work,

LLVM is one of the few project I know that has used the
mysterious GCC front-end. I think it will be a great
contribution to the community if you could writeup and document how to
interface to
the GCC front-end data-structures (like LLVM has done). Specifically:

a) detail the gcc front-end tree data-structures
b) how to go about interfacing to them
c) what are changes that LLVM did to the gcc front end

My interest is to interface to gcc data-structures to produce an
open-source language
independent IL in Ocaml -- like LLVM but at a higher level suitable for program
analysis in Ocaml (like the CIL effort at berkeley -- note CIL folks developed
their C frontend from scratch -- a waste of effort when they could
have leveraged the gcc frontend)
Unfortunately there is very little documentation for the gcc front
end interface.
I have to spend a lot of time code-browsing the gcc code trying to
understand the
gcc code and data-structures. Since you have done this already,
I will really appreciate if you could document your efforts.

This will be a valuable contribution to the community since gcc is 
the ONLY (and defacto standard) open-source compiler for C,C++,
and at the same time its front end interface is very poorly documented.

Thanks and Regards