Re: FFI breaking with -O?

okay, I figured out putting the -fasm after the -O and that seems to cause the problem to go away supporting my theory. For an example of something that breaks, the following will create an error when compiled via-C and not otherwise. #include foreign import ccall touchwin :: Window -> IO CInt for the ncurses included with red hat linux, i think it has something to do with the fact that touchwin is both #defined in terms of other routines AND part of the ncurses library as its own function. I imagine they did this to allow inlining when compiling C as well as external bindings and function pointers to refer to the function. many other routines give warnings which are #definied in similar ways. John On Tue, Sep 10, 2002 at 10:34:04AM +0100, Simon Marlow wrote:

...

I have a variety of C interfaces which are generated with hsc2hs, in particular a ncurses and openssl wrapper. they work perfectly when compiling normally, but when i use the -O or -O2 option, I end up with at the least a ton of C warnings on the /tmp/ghc*.hc file and in some cases a fatal error. as far as i can tell they relate to some odd interaction with the C preprocessor and the generated haskell code. I am not compiling with -fvia-C but it appears to be going via C anyway. Does anyone have any ideas why this might be the case or a workaround for the problem? Perhaps if this is the case, I can force it to not compile via C even when optimizing? John

(the offending code is part of 'ginsu' my gale client implemented in haskell http://repetae.net/john/computer/ginsu/ )

This "shouldn't" happen, although there are occasionally good reasons why it does. Are you including the right header files using the -#include option? Can you send us some sample code to test, or should I try the whole of ginsu?

You can force non-via-C by saying -fasm. Put this flag *after* -O, because -O implies -fvia-C.

Cheers, Simon _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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