Merge pull request #4971 from phadej/leading-comma-2

Leading comma 2

Author: phadej

Cabal/Cabal.cabal

@@ -38,6 +38,8 @@ extra-source-files:
   tests/ParserTests/errors/common2.errors
   tests/ParserTests/errors/common3.cabal
   tests/ParserTests/errors/common3.errors
+  tests/ParserTests/errors/leading-comma.cabal
+  tests/ParserTests/errors/leading-comma.errors
   tests/ParserTests/regressions/Octree-0.5.cabal
   tests/ParserTests/regressions/Octree-0.5.format
   tests/ParserTests/regressions/common.cabal
@@ -55,10 +57,14 @@ extra-source-files:
   tests/ParserTests/regressions/haddock-api-2.18.1-check.cabal
   tests/ParserTests/regressions/issue-774.cabal
   tests/ParserTests/regressions/issue-774.format
+  tests/ParserTests/regressions/leading-comma.cabal
+  tests/ParserTests/regressions/leading-comma.format
   tests/ParserTests/regressions/nothing-unicode.cabal
   tests/ParserTests/regressions/nothing-unicode.format
   tests/ParserTests/regressions/shake.cabal
   tests/ParserTests/regressions/shake.format
+  tests/ParserTests/regressions/wl-pprint-indef.cabal
+  tests/ParserTests/regressions/wl-pprint-indef.format
   tests/ParserTests/warnings/bom.cabal
   tests/ParserTests/warnings/bool.cabal
   tests/ParserTests/warnings/deprecatedfield.cabal
@@ -148,6 +154,7 @@ library
     Distribution.Backpack.ModSubst
     Distribution.Backpack.ModuleShape
     Distribution.Backpack.PreModuleShape
+    Distribution.CabalSpecVersion
     Distribution.Utils.IOData
     Distribution.Utils.LogProgress
     Distribution.Utils.MapAccum
@@ -302,9 +309,11 @@ library
   build-depends:
     transformers,
     mtl >= 2.1 && <2.3,
+    text >= 1.2.2.2 && <1.3,
     parsec >= 3.1.9 && <3.2
   exposed-modules:
-    Distribution.Compat.Parsec
+    Distribution.Compat.Parsing
+    Distribution.Compat.CharParsing
     Distribution.FieldGrammar
     Distribution.FieldGrammar.Class
     Distribution.FieldGrammar.Parsec

Cabal/Distribution/CabalSpecVersion.hs

@@ -0,0 +1,60 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveGeneric #-}
+module Distribution.CabalSpecVersion where
+
+import Prelude ()
+import Distribution.Compat.Prelude
+import qualified Data.Set as Set
+
+-- | Different Cabal-the-spec versions.
+--
+-- We branch based on this at least in the parser.
+--
+data CabalSpecVersion
+    = CabalSpecOld
+    | CabalSpecV20
+    | CabalSpecV22
+  deriving (Eq, Ord, Show, Read, Enum, Bounded, Typeable, Data, Generic)
+
+cabalSpecLatest :: CabalSpecVersion
+cabalSpecLatest = CabalSpecV22
+
+cabalSpecFeatures :: CabalSpecVersion -> Set.Set CabalFeature
+cabalSpecFeatures CabalSpecOld = Set.empty
+cabalSpecFeatures CabalSpecV20 = Set.empty
+cabalSpecFeatures CabalSpecV22 = Set.fromList
+    [ Elif
+    , CommonStanzas
+    ]
+
+cabalSpecSupports :: CabalSpecVersion -> [Int] -> Bool
+cabalSpecSupports CabalSpecOld v = v < [1,25]
+cabalSpecSupports CabalSpecV20 v = v < [2,1]
+cabalSpecSupports CabalSpecV22 _ = True
+
+specHasCommonStanzas :: CabalSpecVersion -> HasCommonStanzas
+specHasCommonStanzas CabalSpecV22 = HasCommonStanzas
+specHasCommonStanzas _            = NoCommonStanzas
+
+specHasElif :: CabalSpecVersion -> HasElif
+specHasElif CabalSpecV22 = HasElif
+specHasElif _            = NoElif
+
+-------------------------------------------------------------------------------
+-- Features
+-------------------------------------------------------------------------------
+
+data CabalFeature
+    = Elif
+    | CommonStanzas
+  deriving (Eq, Ord, Show, Read, Enum, Bounded, Typeable, Data, Generic)
+
+-------------------------------------------------------------------------------
+-- Booleans
+-------------------------------------------------------------------------------
+
+data HasElif = HasElif | NoElif
+  deriving (Eq, Show)
+
+data HasCommonStanzas = HasCommonStanzas | NoCommonStanzas
+  deriving (Eq, Show)