Re: Language extensions - backwards compatibility

The flag -P for traditional gnu cpp (or --noline for stand-alone cpphs) should suppress the initial #line noise.

Does ghc still fail to recognise a module-start pragma, even if the only characters preceding it are whitespace?

I intended to give an example. ---- file foo.h ---- #if __GLASGOW_HASKELL__ == 604 #define PRAGMA(foo) {-# OPTIONS_GHC -X foo #-} #else #define PRAGMA(foo) {-# LANGUAGE foo #-} ---- file Bar.hs ---- #include "foo.h" PRAGMA(MyLanguageOption) module Bar where ---- result ---- $ ghc-6.8.2 -E -cpp -optP-P Bar.hs $ cat Bar.hspp {-# LINE 1 "Bar.hs" #-} {-# LANGUAGE MyLanguageOption #-} module Bar where $ ghc-6.4.1 -E -cpp -optP-P Bar.hs $ cat Bar.hspp {-# OPTIONS_GHC -X MyLanguageOption #-} module Bar where