packages feed

cuda-0.7.5.0: Setup.hs

import Distribution.PackageDescription
import Distribution.PackageDescription.Parse
import Distribution.Simple
import Distribution.Simple.BuildPaths
import Distribution.Simple.Command
import Distribution.Simple.Program.Db
import Distribution.Simple.LocalBuildInfo
import Distribution.Simple.PreProcess                               hiding ( ppC2hs )
import Distribution.Simple.Program
import Distribution.Simple.Setup
import Distribution.Simple.Utils
import Distribution.System
import Distribution.Verbosity

import Control.Exception
import Control.Monad
import Data.Function
import Data.List
import Data.Maybe
import System.Directory
import System.Environment
import System.FilePath
import System.IO.Error
import Text.Printf
import Prelude


-- Configuration
-- -------------

customBuildInfoFilePath :: FilePath
customBuildInfoFilePath = "cuda" <.> "buildinfo"

generatedBuildInfoFilePath :: FilePath
generatedBuildInfoFilePath = customBuildInfoFilePath <.> "generated"

defaultCUDAInstallPath :: Platform -> FilePath
defaultCUDAInstallPath _ = "/usr/local/cuda"  -- windows?


-- Build setup
-- -----------

main :: IO ()
main = defaultMainWithHooks customHooks
  where
    readHook get_verbosity a flags = do
        noExtraFlags a
        getHookedBuildInfo (fromFlag (get_verbosity flags))

    preprocessors = hookedPreProcessors simpleUserHooks

    -- Our readHook implementation uses our getHookedBuildInfo. We can't rely on
    -- cabal's autoconfUserHooks since they don't handle user overwrites to
    -- buildinfo like we do.
    --
    customHooks =
      simpleUserHooks
        { preBuild            = preBuildHook -- not using 'readHook' here because 'build' takes; extra args
        , preClean            = readHook cleanVerbosity
        , preCopy             = readHook copyVerbosity
        , preInst             = readHook installVerbosity
        , preHscolour         = readHook hscolourVerbosity
        , preHaddock          = readHook haddockVerbosity
        , preReg              = readHook regVerbosity
        , preUnreg            = readHook regVerbosity
        , postConf            = postConfHook
        , hookedPreProcessors = ("chs", ppC2hs) : filter (\x -> fst x /= "chs") preprocessors
        }

    -- The hook just loads the HookedBuildInfo generated by postConfHook,
    -- unless there is user-provided info that overwrites it.
    --
    preBuildHook :: Args -> BuildFlags -> IO HookedBuildInfo
    preBuildHook _ flags = getHookedBuildInfo $ fromFlag $ buildVerbosity flags

    -- The hook scans system in search for CUDA Toolkit. If the toolkit is not
    -- found, an error is raised. Otherwise the toolkit location is used to
    -- create a `cuda.buildinfo.generated` file with all the resulting flags.
    --
    postConfHook :: Args -> ConfigFlags -> PackageDescription -> LocalBuildInfo -> IO ()
    postConfHook args flags pkg_descr lbi = do
      let
          verbosity       = fromFlag (configVerbosity flags)
          currentPlatform = hostPlatform lbi
          compilerId_     = compilerId (compiler lbi)
      --
      noExtraFlags args
      generateAndStoreBuildInfo verbosity currentPlatform compilerId_ generatedBuildInfoFilePath
      validateLinker verbosity currentPlatform $ withPrograms lbi
      --
      actualBuildInfoToUse <- getHookedBuildInfo verbosity
      let pkg_descr' = updatePackageDescription actualBuildInfoToUse pkg_descr
      postConf simpleUserHooks args flags pkg_descr' lbi


-- Generates build info with flags needed for CUDA Toolkit to be properly
-- visible to underlying build tools.
--
libraryBuildInfo :: FilePath -> Platform -> Version -> IO HookedBuildInfo
libraryBuildInfo installPath platform@(Platform arch os) ghcVersion = do
  let
      libraryPaths      = [cudaLibraryPath platform installPath]
      includePaths      = [cudaIncludePath platform installPath]

      -- options for GHC
      extraLibDirs'     = libraryPaths
      ccOptions'        = map ("-I"++) includePaths
      ldOptions'        = map ("-L"++) libraryPaths
      ghcOptions        = map ("-optc"++) ccOptions'
                       ++ map ("-optl"++) ldOptions'
                       ++ if os /= Windows
                            then map ("-optl-Wl,-rpath,"++) extraLibDirs'
                            else []
      extraLibs'        = cudaLibraries platform
      frameworks'       = [ "CUDA" | os == OSX ]

      -- options or c2hs
      archFlag          = case arch of
                            I386   -> "-m32"
                            X86_64 -> "-m64"
                            _      -> ""
      emptyCase         = ["-DUSE_EMPTY_CASE" | versionBranch ghcVersion >= [7,8]]
      blocksExtension   = [ "-U__BLOCKS__" | os == OSX ]
      c2hsOptions       = unwords $ map ("--cppopts="++) ("-E" : archFlag : emptyCase ++ blocksExtension)
      c2hsExtraOptions  = ("x-extra-c2hs-options", c2hsOptions)

      addSystemSpecificOptions :: BuildInfo -> IO BuildInfo
      addSystemSpecificOptions bi =
        case os of
          _ -> return bi

  extraGHCiLibs' <- cudaGHCiLibraries platform installPath extraLibs'
  buildInfo'     <- addSystemSpecificOptions $ emptyBuildInfo
    { ccOptions      = ccOptions'
    , ldOptions      = ldOptions'
    , extraLibs      = extraLibs'
    , extraGHCiLibs  = extraGHCiLibs'
    , extraLibDirs   = extraLibDirs'
    , frameworks     = frameworks'
    , options        = [(GHC, ghcOptions) | os /= Windows]
    , customFieldsBI = [c2hsExtraOptions]
    }

  return (Just buildInfo', [])


-- Return the location of the include directory relative to the base CUDA
-- installation.
--
cudaIncludePath :: Platform -> FilePath -> FilePath
cudaIncludePath _ installPath = installPath </> "include"


-- Return the location of the libraries relative to the base CUDA installation.
--
cudaLibraryPath :: Platform -> FilePath -> FilePath
cudaLibraryPath (Platform arch os) installPath = installPath </> libpath
  where
    libpath =
      case (os, arch) of
        (Windows, I386)   -> "Win32"
        (Windows, X86_64) -> "x64"
        (OSX,     _)      -> "lib"    -- MacOS does not distinguish 32- vs. 64-bit paths
        (_,       X86_64) -> "lib64"  -- treat all others similarly
        _                 -> "lib"


-- On Windows and OSX we use different libraries depending on whether we are
-- linking statically (executables) or dynamically (ghci).
--
cudaLibraries :: Platform -> [String]
cudaLibraries (Platform _ os) =
  case os of
    OSX -> ["cudadevrt", "cudart_static"]
    _   -> ["cudart", "cuda"]

cudaGHCiLibraries :: Platform -> FilePath -> [String] -> IO [String]
cudaGHCiLibraries platform@(Platform _ os) installPath libraries =
  case os of
    Windows -> cudaGhciLibrariesWindows platform installPath libraries
    OSX     -> return ["cudart"]
    _       -> return []

-- Windows compatibility function.
--
-- The function is used to populate the extraGHCiLibs list on Windows
-- platform. It takes libraries directory and .lib filenames and returns
-- their corresponding dll filename. (Both filenames are stripped from
-- extensions)
--
-- Eg: "C:\cuda\toolkit\lib\x64" -> ["cudart", "cuda"] -> ["cudart64_65", "ncuda"]
--
cudaGhciLibrariesWindows :: Platform -> FilePath -> [FilePath] -> IO [FilePath]
cudaGhciLibrariesWindows platform installPath libraries = do
  candidates <- mapM importLibraryToDLLFileName [ cudaLibraryPath platform installPath </> lib <.> "lib" | lib <- libraries ]
  return [ dropExtension dll | Just dll <- candidates ]


-- Windows compatibility function.
--
-- CUDA toolkit uses different names for import libraries and their
-- respective DLLs. For example, on 32-bit architecture and version 7.0 of
-- toolkit, `cudart.lib` imports functions from `cudart32_70`.
--
-- The ghci linker fails to resolve this. Therefore, it needs to be given
-- the DLL filenames as `extra-ghci-libraries` option.
--
-- This function takes *a path to* import library and returns name of
-- corresponding DLL.
--
-- Eg: "C:/CUDA/Toolkit/Win32/cudart.lib" -> "cudart32_70.dll"
--
-- Internally it assumes that 'nm' tool is present in PATH. This should be
-- always true, as 'nm' is distributed along with GHC.
--
-- The function is meant to be used on Windows. Other platforms may or may
-- not work.
--
importLibraryToDLLFileName :: FilePath -> IO (Maybe FilePath)
importLibraryToDLLFileName importLibPath = do
  -- Sample output nm generates on cudart.lib
  --
  -- nvcuda.dll:
  -- 00000000 i .idata$2
  -- 00000000 i .idata$4
  -- 00000000 i .idata$5
  -- 00000000 i .idata$6
  -- 009c9d1b a @comp.id
  -- 00000000 I __IMPORT_DESCRIPTOR_nvcuda
  --          U __NULL_IMPORT_DESCRIPTOR
  --          U nvcuda_NULL_THUNK_DATA
  --
  nmOutput <- getProgramInvocationOutput normal (simpleProgramInvocation "nm" [importLibPath])
  return $ find (isInfixOf ("" <.> dllExtension)) (lines nmOutput)


-- Slightly modified version of `words` from base - it takes predicate saying on
-- which characters split.
--
splitOn :: (Char -> Bool) -> String -> [String]
splitOn p s =
  case dropWhile p s of
    [] -> []
    s' -> let (w, s'') = break p s'
          in  w : splitOn p s''

-- Tries to obtain the version `ld`. Throws an exception if failed.
--
getLdVersion :: Verbosity -> FilePath -> IO (Maybe [Int])
getLdVersion verbosity ldPath = do
  -- Version string format is like `GNU ld (GNU Binutils) 2.25.1`
  --                            or `GNU ld (GNU Binutils) 2.20.51.20100613`
  ldVersionString <- getProgramInvocationOutput normal (simpleProgramInvocation ldPath ["-v"])

  let versionText   = last $ words ldVersionString -- takes e. g. "2.25.1"
      versionParts  = splitOn (== '.') versionText
      versionParsed = Just $ map read versionParts

      -- last and read above may throw and message would be not understandable
      -- for user, so we'll intercept exception and rethrow it with more useful
      -- message.
      handleError :: SomeException -> IO (Maybe [Int])
      handleError e = do
          warn verbosity $ printf "cannot parse ld version string: `%s`. Parsing exception: `%s`" ldVersionString (show e)
          return Nothing

  evaluate versionParsed `catch` handleError


-- On Windows GHC package comes with two copies of ld.exe.
--
--  1. ProgramDb knows about the first one: ghcpath\mingw\bin\ld.exe
--  2. This function returns the other one: ghcpath\mingw\x86_64-w64-mingw32\bin\ld.exe
--
-- The second one is the one that does actual linking and code generation.
-- See: https://github.com/tmcdonell/cuda/issues/31#issuecomment-149181376
--
-- The function is meant to be used only on 64-bit GHC distributions.
--
getRealLdPath :: Verbosity -> ProgramDb -> IO (Maybe FilePath)
getRealLdPath verbosity programDb =
  -- TODO: This should ideally work `programFindVersion ldProgram` but for some
  -- reason it does not. The issue should be investigated at some time.
  --
  case lookupProgram ghcProgram programDb of
    Nothing            -> return Nothing
    Just configuredGhc -> do
      let ghcPath        = locationPath $ programLocation configuredGhc
          presumedLdPath = (takeDirectory . takeDirectory) ghcPath </> "mingw" </> "x86_64-w64-mingw32" </> "bin" </> "ld.exe"
      info verbosity $ "Presuming ld location" ++ presumedLdPath
      presumedLdExists <- doesFileExist presumedLdPath
      return $ if presumedLdExists
                 then Just presumedLdPath
                 else Nothing


-- On Windows platform the binutils linker targeting x64 is bugged and cannot
-- properly link with import libraries generated by MS compiler (like the CUDA ones).
-- The programs would correctly compile and crash as soon as the first FFI call is made.
--
-- Therefore we fail configure process if the linker is too old and provide user
-- with guidelines on how to fix the problem.
--
validateLinker :: Verbosity -> Platform -> ProgramDb -> IO ()
validateLinker verbosity (Platform arch os) db =
  when (arch == X86_64 && os == Windows) $ do
    maybeLdPath <- getRealLdPath verbosity db
    case maybeLdPath of
      Nothing     -> warn verbosity $ "Cannot find ld.exe to check if it is new enough. If generated executables crash when making calls to CUDA, please see " ++ windowsHelpPage
      Just ldPath -> do
        debug verbosity $ "Checking if ld.exe at " ++ ldPath ++ " is new enough"
        maybeVersion <- getLdVersion verbosity ldPath
        case maybeVersion of
          Nothing        -> warn verbosity $ "Unknown ld.exe version. If generated executables crash when making calls to CUDA, please see " ++ windowsHelpPage
          Just ldVersion -> do
            debug verbosity $ "Found ld.exe version: " ++ show ldVersion
            when (ldVersion < [2,25,1]) $ die $ windowsLinkerBugMsg ldPath


windowsHelpPage :: String
windowsHelpPage = "https://github.com/tmcdonell/cuda/blob/master/WINDOWS.markdown"

windowsLinkerBugMsg :: FilePath -> String
windowsLinkerBugMsg ldPath = printf (unlines msg) windowsHelpPage ldPath
  where
    msg =
      [ "********************************************************************************"
      , ""
      , "The installed version of `ld.exe` has version < 2.25.1. This version has known bug on Windows x64 architecture, making it unable to correctly link programs using CUDA. The fix is available and MSys2 released fixed version of `ld.exe` as part of their binutils package (version 2.25.1)."
      , ""
      , "To fix this issue, replace the `ld.exe` in your GHC installation with the correct binary. See the following page for details:"
      , ""
      , "  %s"
      , ""
      , "The full path to the outdated `ld.exe` detected in your installation:"
      , ""
      , "> %s"
      , ""
      , "Please download a recent version of binutils `ld.exe`, from, e.g.:"
      , ""
      , "  http://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-binutils-2.25.1-1-any.pkg.tar.xz"
      , ""
      , "********************************************************************************"
      ]


-- Runs CUDA detection procedure and stores .buildinfo to a file.
--
generateAndStoreBuildInfo :: Verbosity -> Platform -> CompilerId -> FilePath -> IO ()
generateAndStoreBuildInfo verbosity platform (CompilerId _ghcFlavor ghcVersion) path = do
  installPath <- findCUDAInstallPath verbosity platform
  hbi         <- libraryBuildInfo installPath platform ghcVersion
  storeHookedBuildInfo verbosity path hbi

storeHookedBuildInfo :: Verbosity -> FilePath -> HookedBuildInfo -> IO ()
storeHookedBuildInfo verbosity path hbi = do
  notice verbosity $ "Storing parameters to " ++ path
  writeHookedBuildInfo path hbi


-- Try to locate CUDA installation by checking (in order):
--
--  1. CUDA_PATH environment variable
--  2. Looking for `nvcc` in `PATH`
--  3. Checking /usr/local/cuda
--
-- In case of failure, calls die with the pretty long message from below.
--
findCUDAInstallPath :: Verbosity -> Platform -> IO FilePath
findCUDAInstallPath verbosity platform = do
  result <- findFirstValidLocation verbosity platform (candidateCUDAInstallPaths verbosity platform)
  case result of
    Just installPath -> do
      notice verbosity $ printf "Found CUDA toolkit at: %s" installPath
      return installPath
    Nothing -> die cudaNotFoundMsg


cudaNotFoundMsg :: String
cudaNotFoundMsg = unlines
  [ "********************************************************************************"
  , ""
  , "The configuration process failed to locate your CUDA installation. Ensure that you have installed both the developer driver and toolkit, available from:"
  , ""
  , "> http://developer.nvidia.com/cuda-downloads"
  , ""
  , "and make sure that `nvcc` is available in your PATH, or set the CUDA_PATH environment variable appropriately. Check the above output log and run the command directly to ensure it can be located."
  , ""
  , "If you have a non-standard installation, you can add additional search paths using --extra-include-dirs and --extra-lib-dirs. Note that 64-bit Linux flavours often require both `lib64` and `lib` library paths, in that order."
  , ""
  , "********************************************************************************"
  ]


-- Function iterates over action yielding possible locations, evaluating them
-- and returning the first valid one. Returns Nothing if no location matches.
--
findFirstValidLocation :: Verbosity -> Platform -> [(IO FilePath, String)] -> IO (Maybe FilePath)
findFirstValidLocation verbosity platform = go
  where
    go :: [(IO FilePath, String)] -> IO (Maybe FilePath)
    go []     = return Nothing
    go (x:xs) = do
      let (path,desc) = x
      info verbosity $ printf "checking for %s" desc
      found <- validateIOLocation verbosity platform path
      if found
        then Just `fmap` path
        else go xs


-- Evaluates IO to obtain the path, handling any possible exceptions.
-- If path is evaluable and points to valid CUDA toolkit returns True.
--
validateIOLocation :: Verbosity -> Platform -> IO FilePath -> IO Bool
validateIOLocation verbosity platform iopath =
  let handler :: IOError -> IO Bool
      handler err = do
        info verbosity (show err)
        return False
  in
  (iopath >>= validateLocation verbosity platform) `catch` handler


-- Checks whether given location looks like a valid CUDA toolkit directory
--
validateLocation :: Verbosity -> Platform -> FilePath -> IO Bool
validateLocation verbosity platform path = do
  -- TODO: Ideally this should check for e.g. cuda.lib and whether it exports
  -- relevant symbols. This should be achievable with some `nm` trickery
  --
  let cudaHeader = cudaIncludePath platform path </> "cuda.h"
  --
  exists <- doesFileExist cudaHeader
  info verbosity $
    if exists
      then printf "Path accepted: %s\n" path
      else printf "Path rejected: %s\nDoes not exist: %s\n" path cudaHeader
  return exists

-- Returns pairs of (action yielding candidate path, String description of that location)
--
candidateCUDAInstallPaths :: Verbosity -> Platform -> [(IO FilePath, String)]
candidateCUDAInstallPaths verbosity platform =
  [ (getEnv "CUDA_PATH", "environment variable CUDA_PATH")
  , (findInPath,         "nvcc compiler executable in PATH")
  , (return defaultPath, printf "default install location (%s)" defaultPath)
  ]
  where
    findInPath :: IO FilePath
    findInPath = do
      nvccPath <- findProgramLocationOrError verbosity "nvcc"
      -- The obtained path is likely TOOLKIT/bin/nvcc. We want to extract the
      -- TOOLKIT part
      return (takeDirectory $ takeDirectory nvccPath)

    defaultPath :: FilePath
    defaultPath = defaultCUDAInstallPath platform


-- NOTE: this function throws an exception when there is no `nvcc` in PATH.
-- The exception contains a meaningful message.
--
findProgramLocationOrError :: Verbosity -> String -> IO FilePath
findProgramLocationOrError verbosity execName = do
  location <- findProgram verbosity execName
  case location of
    Just path -> return path
    Nothing   -> ioError $ mkIOError doesNotExistErrorType ("not found: " ++ execName) Nothing Nothing

findProgram :: Verbosity -> FilePath -> IO (Maybe FilePath)
findProgram verbosity prog = do
  result <- findProgramOnSearchPath verbosity defaultProgramSearchPath prog
  case result of
    Nothing       -> return Nothing
    Just (path,_) -> return (Just path)


-- Reads user-provided `cuda.buildinfo` if present, otherwise loads `cuda.buildinfo.generated`
-- Outputs message informing about the other possibility.
-- Calls die when neither of the files is available.
-- (generated one should be always present, as it is created in the post-conf step)
--
getHookedBuildInfo :: Verbosity -> IO HookedBuildInfo
getHookedBuildInfo verbosity = do
  doesCustomBuildInfoExists <- doesFileExist customBuildInfoFilePath
  if doesCustomBuildInfoExists
    then do
      notice verbosity $ printf "The user-provided buildinfo from file %s will be used. To use default settings, delete this file.\n" customBuildInfoFilePath
      readHookedBuildInfo verbosity customBuildInfoFilePath
    else do
      doesGeneratedBuildInfoExists <- doesFileExist generatedBuildInfoFilePath
      if doesGeneratedBuildInfoExists
        then do
          notice verbosity $ printf "Using build information from '%s'.\n" generatedBuildInfoFilePath
          notice verbosity $ printf "Provide a '%s' file to override this behaviour.\n" customBuildInfoFilePath
          readHookedBuildInfo verbosity generatedBuildInfoFilePath
        else
          die $ printf "Unexpected failure. Neither the default %s nor custom %s exist.\n" generatedBuildInfoFilePath customBuildInfoFilePath


-- Replicate the default C2HS preprocessor hook here, and inject a value for
-- extra-c2hs-options, if it was present in the buildinfo file
--
-- Everything below copied from Distribution.Simple.PreProcess
--
ppC2hs :: BuildInfo -> LocalBuildInfo -> PreProcessor
ppC2hs bi lbi
    = PreProcessor {
        platformIndependent = False,
        runPreProcessor     = \(inBaseDir, inRelativeFile)
                               (outBaseDir, outRelativeFile) verbosity ->
          rawSystemProgramConf verbosity c2hsProgram (withPrograms lbi) . filter (not . null) $
            maybe [] words (lookup "x-extra-c2hs-options" (customFieldsBI bi))
            ++ ["--include=" ++ outBaseDir]
            ++ ["--cppopts=" ++ opt | opt <- getCppOptions bi lbi]
            ++ ["--output-dir=" ++ outBaseDir,
                "--output=" ++ outRelativeFile,
                inBaseDir </> inRelativeFile]
      }

getCppOptions :: BuildInfo -> LocalBuildInfo -> [String]
getCppOptions bi lbi
    = hcDefines (compiler lbi)
   ++ ["-I" ++ dir | dir <- includeDirs bi]
   ++ [opt | opt@('-':c:_) <- ccOptions bi, c `elem` "DIU"]

hcDefines :: Compiler -> [String]
hcDefines comp =
  case compilerFlavor comp of
    GHC  -> ["-D__GLASGOW_HASKELL__=" ++ versionInt version]
    JHC  -> ["-D__JHC__=" ++ versionInt version]
    NHC  -> ["-D__NHC__=" ++ versionInt version]
    Hugs -> ["-D__HUGS__"]
    _    -> []
  where version = compilerVersion comp

-- TODO: move this into the compiler abstraction
-- FIXME: this forces GHC's crazy 4.8.2 -> 408 convention on all the other
-- compilers. Check if that's really what they want.
versionInt :: Version -> String
versionInt (Version { versionBranch = [] })      = "1"
versionInt (Version { versionBranch = [n] })     = show n
versionInt (Version { versionBranch = n1:n2:_ }) = printf "%d%02d" n1 n2