Added use of GHC API for compiling to a file

* Invoke using 'compileToFile' function

Data/Array/Accelerate/Repa.hs

@@ -11,6 +11,7 @@
 module Data.Array.Accelerate.Repa
    ( Arrays
    , run
+   , compileToFile
    )
    where
 
@@ -22,23 +23,50 @@ import Data.Array.Accelerate.Repa.Stencil (stencilDoc)
 
 import Text.PrettyPrint
 
--- | Used to compile and run an embedded array program using the Repa backend
---run :: Arrays a => Smart.Acc a -> String
---run = evalAcc . Smart.convertAcc
+import GHC       -- For compiling and running using GHC API
+import GHC.Paths (libdir) -- simplifies use of GHC API
+import System.IO -- For writing source to a file
 
+-- | Used to compile and run an embedded array program using the Repa backend
 run :: Arrays a => Smart.Acc a -> String
 run acc = show $
    headS $$ (nest 1 (evalAcc $ Smart.convertAcc acc))
          $$ tailS
          $+$ text " "
          $$ stencilDoc
 
+compileToFile :: Arrays a => Maybe String -> Smart.Acc a -> IO ()
+compileToFile targetFile acc = do
+   let f = case targetFile of
+              Just s -> s
+              Nothing -> defaultFile
+   -- writes source to file as currently can't compile from String
+   writeFile f $ run acc
+   -- using GHC API from here
+   r <- loadAndCompile f
+   case r of
+      Just err -> error err
+      Nothing  -> return ()
+
+loadAndCompile :: String -> IO (Maybe String)
+loadAndCompile targetFile = runGhc (Just libdir) $ do
+   dflags <- getSessionDynFlags
+   setSessionDynFlags (dflags{
+      optLevel = 2
+      })
+   target <- guessTarget targetFile Nothing
+   addTarget target
+   r <- load LoadAllTargets
+   return $ case r of
+      Failed    -> Just "Error in module loading"
+      Succeeded -> Nothing
+
 headS :: Doc
 {-# INLINE headS #-}
 headS =
    text "{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, TypeOperators #-}" $+$
    text "{-# LANGUAGE FlexibleContexts #-}" $+$
-   text "module AccRepa where" $+$
+   text "module" <+> text modName <+> text "where" $+$
    text "import Data.Array.Repa as Repa" $+$
    text "import Data.Bits -- required for Prim ops" $+$
    text "import Data.Char -- required for Prim ops" $+$
@@ -51,3 +79,11 @@ headS =
 tailS :: Doc
 {-# INLINE tailS #-}
 tailS = empty
+
+modName :: String
+{-# INLINE modName #-}
+modName = "Main"
+
+defaultFile :: String
+{-# INLINE defaultFile #-}
+defaultFile = "AccRepa.hs"

accelerate-repa.cabal

@@ -18,7 +18,9 @@ Library
    Build-depends: repa == 2.*,
                   accelerate == 0.9.*,
                   base,
-                  pretty == 1.1.*
+                  pretty == 1.1.*,
+                  ghc-paths == 0.1.*,
+                  ghc == 7.2.*
 
    Exposed-modules: Data.Array.Accelerate.Repa
    Other-modules:   Data.Array.Accelerate.Repa.Evaluations