sven,http://www.haskell.org/platform/mac.html has a wrapper script that makes clang play nice with CPP, though a simpler alternative one can be found on manuel's page here http://justtesting.org/post/64947952690/the-glasgow-haskell-compiler-ghc-on-os-x-10-9 . That said, it also doesnt work for all use case, hence why i generally recommend people also have gcc installed.

there are plans post 7.8 release to give ghc a haskell native CPP analogue, but thats not happening for 7.8

HP + ghc 7.6 users have to use a clang wrapper script like the above, probably http://justtesting.org/post/64947952690/the-glasgow-haskell-compiler-ghc-on-os-x-10-9 is the simplest one you an recommend, because it'll worth with haskell platform and none haskell platform systems.

On Thu, Jan 2, 2014 at 2:37 PM, Sven Panne <svenpanne@gmail.com> wrote:

2014/1/2 Carter Schonwald <carter.schonwald@gmail.com>:

> Hey Sven: the simplest solution is to have users install and use GCC rather
> than clang.

Hmmm, if clang is the default what people get on Mac OS X, I consider
that a non-solution... :-) Furthermore: How will the upcoming Haskell
Platform release handle these problems (clang vs. GCC, my OpenGLRaw
problem)?