Use ghc-paths to get the lib dir

The path can still be overridden using the -B flag. It's not longer
required to pass the lib dir to the program that runs the test suite.

4 files changed, 13 insertions, 10 deletions

diff --git a/haddock.cabal b/haddock.cabal
index 3be3d1ea..7883d52f 100644
--- a/haddock.cabal
+++ b/haddock.cabal
@@ -17,6 +17,7 @@ build-depends:
   base,
   haskell98,
   ghc >= 6.8.2 && < 6.9,
+  ghc-paths,
   filepath,
   directory,
   pretty,
diff --git a/src/Haddock/Options.hs b/src/Haddock/Options.hs
index 6e5514cf..d1b20d3a 100644
--- a/src/Haddock/Options.hs
+++ b/src/Haddock/Options.hs
@@ -91,7 +91,7 @@ options :: Bool -> [OptDescr Flag]
 options backwardsCompat =
   [
    Option ['B']  []     (ReqArg Flag_GhcLibDir "DIR")
-	"path to the GHC lib dir, e.g /usr/lib/ghc",
+	"path to the GHC lib dir, to override the default path",
    Option ['o']  ["odir"]     (ReqArg Flag_OutputDir "DIR")
 	"directory in which to put the output files",
    Option ['l']  ["lib"]         (ReqArg Flag_Lib "DIR") 
diff --git a/src/Main.hs b/src/Main.hs
index f19ae659..3626abe4 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -34,6 +34,7 @@ import System.Exit
 import System.Environment
 
 import GHC
+import GHC.Paths
 import DynFlags
 import Bag
 import Util (handleDyn)
@@ -111,8 +112,12 @@ main = handleTopExceptions $ do
 
   if not (null fileArgs)
     then do
+
+      let libDir
+            | Just dir <- getGhcLibDir flags = dir
+            | otherwise = libdir -- from GHC.Paths
+
       -- initialize GHC
-      libDir <- getGhcLibDir flags
       (session, dynflags) <- startGhc libDir (ghcFlags flags)
 
       -- get packages supplied with --read-interface
@@ -275,8 +280,8 @@ dumpInterfaceFile ifaces homeLinks flags =
 
 getGhcLibDir flags =
   case [ dir | Flag_GhcLibDir dir <- flags ] of
-    [] -> throwE "no GHC lib dir specified"
-    xs -> return $ last xs
+    [] -> Nothing
+    xs -> Just $ last xs
 
 
 handleEasyFlags flags fileArgs = do
diff --git a/tests/runtests.hs b/tests/runtests.hs
index ac6b293e..74259fbe 100644
--- a/tests/runtests.hs
+++ b/tests/runtests.hs
@@ -10,11 +10,8 @@ import Text.Regex
 
 
 main = do
-  args <- getArgs
-  when (null args) $ error "You must give the path to the GHC lib dir as an argument"  
   putStrLn "Running tests..."
-  let libdir = head args
-  test libdir
+  test
   putStrLn "All tests passed!"
 
 
@@ -43,11 +40,11 @@ check modules = do
         putStrLn $ "Pass: " ++ mod ++ " (no .ref file)"
  
 
-test libdir = do
+test = do
   contents <- getDirectoryContents "tests"
   let mods = filter ((==) ".hs" . takeExtension) contents
   let outdir = "output"
   let mods' = map ("tests" </>) mods
-  code <- system $ printf "haddock -B %s -w -o %s -h --optghc=-fglasgow-exts --optghc=-w %s" libdir outdir (unwords mods')
+  code <- system $ printf "haddock -w -o %s -h --optghc=-fglasgow-exts --optghc=-w %s" outdir (unwords mods')
   unless (code == ExitSuccess) $ error "Haddock run failed! Exiting."
   check mods