On Wed, Mar 15, 2006 at 04:13:19PM +0000, Simon Marlow wrote:
There's a lot to be said for using runtime tests instead of conditional compilation, I agree. However, it can't be used exclusively: you can't choose between two foreign calls this way, for example, because one of the calls won't link.
A scheme I was considering for jhc was to (optionally) replace any foreign calls that don't link with 'error', a solution for ghc might be to include stub functions with the 'weak' attribute set in the object file for any potentially non-existing functions. then the system versions will override them if they exist, otherwise the stub functions will be called. perhaps there is room for a FFI extension there? allowing 'weak' to be specified on FFI imports that means 'don't complain if the system doesn't provide this function' John -- John Meacham - ⑆repetae.net⑆john⑈