[commit: ghc] master: Give suggestions for unrecognised command line arguments (82373c7)

[Paolo Capriotti]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/82373c76fb895d6f713b19f0c58b17f2d6ef35c4

>---------------------------------------------------------------

commit 82373c76fb895d6f713b19f0c58b17f2d6ef35c4
Author: Joachim Breitner <mail at joachim-breitner.de>
Date:   Thu Aug 9 16:10:56 2012 +0200

    Give suggestions for unrecognised command line arguments

>---------------------------------------------------------------

 ghc/Main.hs |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/ghc/Main.hs b/ghc/Main.hs
index 1e9d0a2..5eda655 100644
--- a/ghc/Main.hs
+++ b/ghc/Main.hs
@@ -791,5 +791,10 @@ abiHash strs = do
 -- Util
 
 unknownFlagsErr :: [String] -> a
-unknownFlagsErr fs = ghcError (UsageError ("unrecognised flags: " ++ unwords fs))
-
+unknownFlagsErr fs = ghcError $ UsageError $ concatMap oneError fs
+  where
+    oneError f =
+        "unrecognised flag: " ++ f ++ "\n" ++
+        (case fuzzyMatch f (nub allFlags) of
+            [] -> ""
+            suggs -> "did you mean one of:\n" ++ unlines (map ("  " ++) suggs))