On 9 September 2010 22:10, Mathew de Detrich <dete...@gmail.com> wrote: > It should also hopefully make using Haskell packages on windows that use C > sources less painful > Clang could also make using FFI with C++ much easier (for reasons stated > above) > Thoughts?
I don't think it would make it any easier to use C/C++ from Haskell at the moment. LLVM for static compilation works by compiling to assembly. After that it has no support. So we use gcc to finish off the rest of the job; producing object code and linking. There is a pretty cool project going on in LLVM at the moment of integrating an assembler into LLVM so that it can directly produce object code. This should mean that the LLVM backend wouldn't need gcc anymore (but obviously gcc will still be needed by ghc as a whole). As David Peixotto mentioned though, the ghc runtime can't be built by clang. There is probably a few reason but a main one is that Clang doesn't support gcc's global register variable extension (register pinning). The LLVM guys also have no plans to support this feature so unless we want to stop using this extension we are stuck with using gcc. I think the main advantage to trying to use Clang for compiling C/C++ would be that it would enable us to do whole program optimisation across Haskell and C/C++. It could also make cross compiling slightly easier. These ideas are defiantly something I'd like to investigate more in the future. On 10 September 2010 10:08, John Lask <jvl...@hotmail.com> wrote: > In fact I would like a lot more information on what is being proposed with > respect of a LLVM backend and any changes to the compiler tool chain. What would you like to know? If you're talking just about the new LLVM backend for GHC (not the proposal here of using clang) then the effect on the end user is nothing. The LLVM backend compiles an individual Haskell module to LLVM assembly, which is then compiled to native assembly by the 'llc' tool. This gets you now to the same place as the native code generator, where gcc is used to compiled the assembly to an object file. Obviously there is a new dependency on having LLVM 2.7 or greater installed but that should be it. Cheers, David _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
