logfloat-0.12 ============= In general, logfloat is a simple package and should be easy to install. The specifics are a bit murky however, since we use CPP and the FFI and want to retain portability, and due to the rapid evolution of Cabal and other development tools. This document will walk you through the ins and outs for all supported configurations. If you run into issues about missing or similar, then see the FFI Problems section. If you want to compile Haddock documentation, then see that section. Building for GHC (6.8 and above) ================================ Installation under GHC is simple using the standard Cabal build loop: runhaskell Setup.hs configure runhaskell Setup.hs build runhaskell Setup.hs copy runhaskell Setup.hs register The logfloat package is no longer supported for GHC 6.6, though it could probably be made to work with it by changing LANGUAGE pragma into the appropriate OPTIONS_GHC equivalents. Since it's not supported anymore, more significant changes may have become necessary as well. Building for Hugs (September 2006) ================================== Installation under Hugs is unfortunately more complicated due to some option-passing bugs in Cabal. You should be able to build things with these modifications to the usual Cabal build loop: runhaskell Setup.hs configure --hugs \ --with-cpphs="`which cpphs-hugs`" \ --ffihugs-options="-98 +o" \ --ffihugs-option=-F'cpp -P -traditional -D__HUGS__=200609 -D__USE_FFI__' runhaskell Setup.hs build runhaskell Setup.hs copy runhaskell Setup.hs register Hugs installs cpphs under the name "cpphs-hugs" by default. The `which` command will try to resolve the location, assuming it's on your $PATH. If it isn't, then change the --with-cpphs= flag to point to where cpphs is installed on your system. Some additional details about difficulties with building for Hugs can be found in this blog post and the bug reports: http://winterkoninkje.livejournal.com/60707.html http://hackage.haskell.org/trac/hackage/ticket/526 http://hackage.haskell.org/trac/hackage/ticket/527 And while previous versions of Cabal could build this package (with the above commandline to work around those bugs), Hugs support is broken in Cabal 1.8 (including at least 1.8.0.2 through 1.8.0.6): http://hackage.haskell.org/trac/hackage/ticket/633 FFI Problems ============ The logfloat package uses the FFI to access functions in libm to improve accuracy. These functions are part of the ISO C 1999 standard and are supported on most systems, however they're not part of the ANSI C standard nor the System V standard and so they might be unavailable on some systems. If you encounter errors during build about not being able to find , not having prototypes for functions, or linking errors, then you are probably on such a system. In order to use pure Haskell and disable the FFI, pass -f-useFFI during the configure phase to disable the useFFI flag. (If compiling for Hugs, also be sure *not* to pass -D__USE_FFI__ to the cpp filter for ffihugs.) This will degrade the accuracy of certain operations, but should still compile cleanly. If you run into errors like "error: 'log1p' redeclared as different kind of symbol" this is due to a bug in GHC 6.10.1 where you can't use both -fvia-C and the FFI. This bug should be circumvented for the moment, but resolving it is still a work in progress. See the bug report (which is resolved in GHC 6.10.2): http://hackage.haskell.org/trac/ghc/ticket/3117 Windows FFI =========== The logfloat package builds and installs cleanly on Windows XP using GHC 6.10.1 (without needing Cygwin nor Mingw/Msys). The C functions reside in libmingwex.a which is bundled with GHC on WinXP. However, it does not work from the GHCi debugger and gives errors like "can't load .so/.DLL for: m (addDLL: could not load DLL)". If you know how to fix this issue or have further details on Windows compatability, please contact the maintainer. Haddock Documentation ===================== In Cabal 1.2 there is a bug in the handling of building Haddock documentation when CPP is involved. These issues have been fixed in Cabal 1.6, but here are the instructions if you're on older systems. In Cabal 1.2 the cpp-options field is not passed to Haddock, and therefore any macros defined there are not seen, which can cause Haddock to fail. The old workaround was to define CPP macros in the ghc-options field which *does* get passed to Haddock. This is now considered bad style and is forbidden by Hackage. It appears that passing --haddock-option=... or --ghc-option=... flags during configure does not have the same effect as defining the field. Therefore, in order to properly compile Haddock documentation on Cabal 1.2, you should go into logfloat.cabal and uncomment the ghc-options fields which declare CPP macros -D__USE_FFI__ and -D__HUGS__=200609. If you know of a better workaround for this configuration, contact the maintainer.