Implement -XKindSignatures

compiler/main/DynFlags.hs

@@ -185,6 +185,7 @@ data DynFlag
    | Opt_RelaxedPolyRec			-- -X=RelaxedPolyRec
    | Opt_MagicHash
    | Opt_EmptyDataDecls
+   | Opt_KindSignatures
 
    -- optimisation opts
    | Opt_Strictness
@@ -1095,6 +1096,7 @@ fFlags = [
 xFlags :: [(String, DynFlag)]
 xFlags = [
   ( "MagicHash",                        Opt_MagicHash ),
+  ( "KindSignatures",                   Opt_KindSignatures ),
   ( "EmptyDataDecls",                   Opt_EmptyDataDecls ),
   ( "FI",				Opt_FFI ),  -- support `-ffi'...
   ( "FFI",				Opt_FFI ),  -- ...and also `-fffi'
@@ -1141,6 +1143,7 @@ glasgowExtsFlags = [ Opt_GlasgowExts
 		   , Opt_ScopedTypeVariables
 		   , Opt_MagicHash
            , Opt_EmptyDataDecls
+           , Opt_KindSignatures
 		   , Opt_TypeFamilies ]
 
 ------------------

compiler/parser/Lexer.x

@@ -649,7 +649,7 @@ reservedSymsFM = listToUFM $
        ,("-",	ITminus, 	0)
        ,("!",	ITbang, 	0)
 
-       ,("*",	ITstar,		bit glaExtsBit .|. 
+       ,("*",	ITstar,		bit glaExtsBit .|. bit kindSigsBit .|.
 				bit tyFamBit)	    -- For data T (a::*) = MkT
        ,(".",	ITdot,		bit tvBit)	    -- For 'forall a . t'
 
@@ -1518,6 +1518,7 @@ bangPatBit = 8	-- Tells the parser to understand bang-patterns
 tyFamBit   = 9	-- indexed type families: 'family' keyword and kind sigs
 haddockBit = 10 -- Lex and parse Haddock comments
 magicHashBit = 11 -- # in both functions and operators
+kindSigsBit = 12 -- # in both functions and operators
 
 glaExtsEnabled, ffiEnabled, parrEnabled :: Int -> Bool
 glaExtsEnabled   flags = testBit flags glaExtsBit
@@ -1531,6 +1532,7 @@ bangPatEnabled   flags = testBit flags bangPatBit
 tyFamEnabled     flags = testBit flags tyFamBit
 haddockEnabled   flags = testBit flags haddockBit
 magicHashEnabled flags = testBit flags magicHashBit
+kindSigsEnabled  flags = testBit flags kindSigsBit
 
 -- PState for parsing options pragmas
 --
@@ -1583,6 +1585,7 @@ mkPState buf loc flags  =
 	       .|. tyFamBit     `setBitIf` dopt Opt_TypeFamilies flags
 	       .|. haddockBit   `setBitIf` dopt Opt_Haddock      flags
 	       .|. magicHashBit `setBitIf` dopt Opt_MagicHash    flags
+	       .|. kindSigsBit  `setBitIf` dopt Opt_KindSignatures flags
       --
       setBitIf :: Int -> Bool -> Int
       b `setBitIf` cond | cond      = bit b

compiler/typecheck/TcTyClsDecls.lhs

@@ -695,6 +695,7 @@ tcTyClDecl1 calc_isrec
   ; unbox_strict <- doptM Opt_UnboxStrictFields
   ; gla_exts     <- doptM Opt_GlasgowExts
   ; empty_data_decls <- doptM Opt_EmptyDataDecls
+  ; kind_signatures <- doptM Opt_KindSignatures
   ; gadt_ok      <- doptM Opt_GADTs
   ; is_boot	 <- tcIsHsBoot	-- Are we compiling an hs-boot file?
 
@@ -702,7 +703,7 @@ tcTyClDecl1 calc_isrec
   ; checkTc (gadt_ok || h98_syntax) (badGadtDecl tc_name)
 
 	-- Check that we don't use kind signatures without Glasgow extensions
-  ; checkTc (gla_exts || isNothing mb_ksig) (badSigTyDecl tc_name)
+  ; checkTc (kind_signatures || isNothing mb_ksig) (badSigTyDecl tc_name)
 
 	-- Check that the stupid theta is empty for a GADT-style declaration
   ; checkTc (null stupid_theta || h98_syntax) (badStupidTheta tc_name)
@@ -1209,7 +1210,7 @@ newtypeFieldErr con_name n_flds
 badSigTyDecl tc_name
   = vcat [ ptext SLIT("Illegal kind signature") <+>
 	   quotes (ppr tc_name)
-	 , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow kind signatures")) ]
+	 , nest 2 (parens $ ptext SLIT("Use -XKindSignatures to allow kind signatures")) ]
 
 badFamInstDecl tc_name
   = vcat [ ptext SLIT("Illegal family instance for") <+>