Why does GCC-Windows depend on cygwin?

Question

I\'m not a C++ developer, but I\'ve always been interested in compilers, and I\'m interested in tinkering with some of the GCC stuff (particularly LLVM).

On Windows,

Answer 1

I'm not a C++ developer, but I've always been interested in compilers, and I'm interested in tinkering with some of the GCC stuff (particularly LLVM)

Note that LLVM and GCC are not related. LLVM is largely the result of the research done by Chris Lattner (http://llvm.org/developers.cgi) about modern optimization. His papers are available on http://llvm.org. Nowadays, it is heavily sponsored by Apple. GCC's C/C++/Obj-C frontend is used for llvm-gcc, which emits LLVM machine code (and after a ton of optimizations in llvm, a final executable comes out); llvm-gcc is a kind of hack to couple some ready C/C++/Obj-C-frontend to LLVM.

Note anyways that the LLVM crew also builds an own, complete C/C++/Obj-C compiler, called clang. It's C implementation is near complete, C++ support is getting better and better, dunno about Obj-C though.

So, if someone says "compiler llvm", he really either means llvm-gcc, or clang. LLVM itself is just the Low Level Virtual Machine, with only a handful of instructions in Static Single Assignment form (approx. 32 instructions, afair), but a megaton of optimization passes upon thy syntax tree.