Updated build setup to run build-parser.sh automatically

IHaskell.cabal

@@ -39,7 +39,7 @@ maintainer:          andrew.gibiansky@gmail.com
 
 category:            Development
 
-build-type:          Simple
+build-type:          Custom
 
 -- Constraint on the version of Cabal needed to build this package.
 cabal-version:       >=1.8
@@ -75,6 +75,8 @@ library
 executable IHaskell
   -- .hs or .lhs file containing the Main module.
   main-is:             Main.hs
+
+  build-tools:         happy, cpphs
   
   -- Modules included in this executable, other than Main.
   other-modules:       

Setup.hs

 import Distribution.Simple
+import System.Cmd
+import Control.Monad
 
-main ::  IO ()
-main = defaultMain
+main :: IO ()
+main = defaultMainWithHooks simpleUserHooks{
+    preConf = \args confFlags -> do
+      buildParser
+      preConf simpleUserHooks args confFlags
+}
+
+buildParser = system "./build-parser.sh"

build-parser.sh

 #!/bin/sh
+# Called from Setup.hs.
+
+# Preprocess the GHC parser we're using to CPP subs.
 cpphs --linepragma --text HaskellParser.y.pp -OParser.y
+
+# Compile the parser and remove intermediate file.
 happy Parser.y
 rm Parser.y
+
+# Move output Haskell to source directory.
 mkdir -p IHaskell/GHC
 mv Parser.hs IHaskell/GHC/HaskellParser.hs