ghc and MacOS X

[sebastien carlier]

> EXTRA_*_OPTS are intended for use on the command line (eg. make
> EXTRA_HC_OPTS=-v).
> 
> If you want to add something to CC_OPTS everywhere in the tree, use
> 
>         SRC_CC_OPTS += -traditional-cpp
> 
> in build.mk.
> 
> But I'm not sure exactly what you're trying to do - could you elaborate?

MacOS X uses a special cpp which supports precompiled headers and
Objective C syntax.  But it does not support GNU extensions to cpp.
The -traditional-cpp flag tells the driver to use the normal GNU cpp,
which is often required (OCaml also needs it).
This flag should always be set on MacOS X (and Darwin), except when
using Apple's frameworks.

--
Sebastien

PS: Sorry for not replying to this earlier, I thought I had subscribed
the mailing list (I did had not seen the web interface, I followed
instructions from some file inside ghc's sources - it's probably out
of date).  Last week I was too busy to investigate.