[commit: ghc] ghc-8.0: Extend `-Wunrecognised-warning-flag` to cover `-f(no-)warn-*` (3d345e8)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : ghc-8.0
Link       : http://ghc.haskell.org/trac/ghc/changeset/3d345e8f1551b21980aeef9110463ecd2ee2686f/ghc

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

commit 3d345e8f1551b21980aeef9110463ecd2ee2686f
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Tue Feb 23 23:13:33 2016 +0100

    Extend `-Wunrecognised-warning-flag` to cover `-f(no-)warn-*`
    
    The original implementation for #11429 covers only `-W*` flags. However,
    old packages will continue to use `-f(no-)warn-*` flags, so it seems
    desirable to have `-Wunrecognised-warning-flag` apply to those legacy aliases
    as well.
    
    (cherry picked from commit 32a9a7f514bdd33ff72a673ade2591e4e815be58)


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

3d345e8f1551b21980aeef9110463ecd2ee2686f
 compiler/main/DynFlags.hs | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index c02e0d3..57fd140 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -2931,14 +2931,16 @@ dynamic_flags_deps = [
     wWarningFlagsDeps
  ++ map (mkFlag turnOff "fno-warn-" unSetWarningFlag . hideFlag)
     wWarningFlagsDeps
+ ++ [ (NotDeprecated, unrecognisedWarning "W")
+    , (NotDeprecated, unrecognisedWarning "fwarn-")
+    , (NotDeprecated, unrecognisedWarning "fno-warn-") ]
  ++ map (mkFlag turnOn  "f"         setExtensionFlag  ) fLangFlagsDeps
  ++ map (mkFlag turnOff "fno-"      unSetExtensionFlag) fLangFlagsDeps
  ++ map (mkFlag turnOn  "X"         setExtensionFlag  ) xFlagsDeps
  ++ map (mkFlag turnOff "XNo"       unSetExtensionFlag) xFlagsDeps
  ++ map (mkFlag turnOn  "X"         setLanguage       ) languageFlagsDeps
  ++ map (mkFlag turnOn  "X"         setSafeHaskell    ) safeHaskellFlagsDeps
- ++ [ (NotDeprecated, unrecognisedWarning)
-    , make_dep_flag defFlag "XGenerics"
+ ++ [ make_dep_flag defFlag "XGenerics"
         (NoArg $ return ())
                   ("it does nothing; look into -XDefaultSignatures " ++
                    "and -XDeriveGeneric for generic programming support.")
@@ -2949,13 +2951,13 @@ dynamic_flags_deps = [
 
 -- | This is where we handle unrecognised warning flags. We only issue a warning
 -- if -Wunrecognised-warning-flags is set. See Trac #11429 for context.
-unrecognisedWarning :: Flag (CmdLineP DynFlags)
-unrecognisedWarning = defFlag "W" (Prefix action)
+unrecognisedWarning :: String -> Flag (CmdLineP DynFlags)
+unrecognisedWarning prefix = defFlag prefix (Prefix action)
   where
     action :: String -> EwM (CmdLineP DynFlags) ()
     action flag = do
       f <- wopt Opt_WarnUnrecognisedWarningFlags <$> liftEwM getCmdLineState
-      when f $ addWarn $ "unrecognised warning flag: -W" ++ flag
+      when f $ addWarn $ "unrecognised warning flag: -" ++ prefix ++ flag
 
 -- See Note [Supporting CLI completion]
 package_flags_deps :: [(Deprecation, Flag (CmdLineP DynFlags))]