[WIP] Implement External Custom Setup

Cabal/Distribution/Package.hs

@@ -41,6 +41,7 @@ module Distribution.Package (
 
         -- * Package source dependencies
         Dependency(..),
+        ExeDependency(..),
         thisPackageVersion,
         notThisPackageVersion,
         simplifyDependency,
@@ -291,7 +292,16 @@ mkLegacyUnitId = newSimpleUnitId . mkComponentId . display
 data Dependency = Dependency PackageName VersionRange
                   deriving (Generic, Read, Show, Eq, Typeable, Data)
 
+-- | Describes a dependency on an executable from a package
+--
+data ExeDependency = ExeDependency
+                     PackageName
+                     String -- ^ name of executable component of package
+                     VersionRange
+                     deriving (Generic, Read, Show, Eq, Typeable, Data)
+
 instance Binary Dependency
+instance Binary ExeDependency
 
 instance Text Dependency where
   disp (Dependency name ver) =
@@ -303,7 +313,20 @@ instance Text Dependency where
              Parse.skipSpaces
              return (Dependency name ver)
 
+instance Text ExeDependency where
+  disp (ExeDependency name exe ver) =
+    (disp name <<>> Disp.text ":" <<>> Disp.text exe) <+> disp ver
+
+  parse = do name <- parse
+             _ <- Parse.char ':'
+             exe <- Parse.munch1 isAlphaNum
+             Parse.skipSpaces
+             ver <- parse <++ return anyVersion
+             Parse.skipSpaces
+             return (ExeDependency name exe ver)
+
 instance NFData Dependency where rnf = genericRnf
+instance NFData ExeDependency where rnf = genericRnf
 
 thisPackageVersion :: PackageIdentifier -> Dependency
 thisPackageVersion (PackageIdentifier n v) =

Cabal/Distribution/PackageDescription/Check.hs

@@ -205,6 +205,7 @@ checkSanity pkg =
   ++ concatMap (checkExecutable pkg) (executables pkg)
   ++ concatMap (checkTestSuite  pkg) (testSuites pkg)
   ++ concatMap (checkBenchmark  pkg) (benchmarks pkg)
+  ++ concatMap (checkSetup      pkg) (maybeToList $ setupBuildInfo pkg)
 
   ++ catMaybes [
 
@@ -404,6 +405,16 @@ checkBenchmark _pkg bm =
       BenchmarkExeV10 _ f -> takeExtension f `notElem` [".hs", ".lhs"]
       _                   -> False
 
+checkSetup :: PackageDescription -> SetupBuildInfo -> [PackageCheck]
+checkSetup _pkg sbinfo =
+  catMaybes [
+
+    check (not $ null (setupDepends sbinfo) && null (setupTool sbinfo)) $
+      PackageBuildImpossible $
+           "Cannot specify both setup-depends and setup-tool"
+
+    ]
+
 -- ------------------------------------------------------------
 -- * Additional pure checks
 -- ------------------------------------------------------------

Cabal/Distribution/PackageDescription/Parse.hs

@@ -532,8 +532,11 @@ sourceRepoFieldDescrs =
 setupBInfoFieldDescrs :: [FieldDescr SetupBuildInfo]
 setupBInfoFieldDescrs =
     [ commaListFieldWithSep vcat "setup-depends"
-        disp         parse
-        setupDepends (\xs binfo -> binfo{setupDepends=xs})
+        disp                parse
+        setupDepends (\xs sbinfo  -> sbinfo { setupDepends = xs })
+    , simpleField "setup-tool"
+        (maybe mempty disp) (fmap Just parse)
+        setupTool    (\val sbinfo -> sbinfo { setupTool = val })
     ]
 
 -- ---------------------------------------------------------------

Cabal/Distribution/PackageDescription/Parsec/FieldDescr.hs

@@ -541,11 +541,13 @@ sourceRepoFieldDescrs =
 setupBInfoFieldDescrs :: [FieldDescr SetupBuildInfo]
 setupBInfoFieldDescrs =
     [ commaListFieldWithSep vcat "setup-depends"
-        disp         parsec
-        setupDepends (\xs binfo -> binfo{setupDepends=xs})
+        disp                parsec
+        setupDepends (\xs sbinfo  -> sbinfo { setupDepends = xs })
+    , simpleField "setup-tool"
+        (maybe mempty disp) (Just <$> parsec)
+        setupTool    (\val sbinfo -> sbinfo { setupTool = val })
     ]
 
-
 -------------------------------------------------------------------------------
 -- Utilities
 -------------------------------------------------------------------------------

Cabal/Distribution/Parsec/Class.hs

@@ -34,7 +34,7 @@ import           Distribution.License                         (License (..))
 import           Distribution.ModuleName                      (ModuleName)
 import qualified Distribution.ModuleName                      as ModuleName
 import           Distribution.Package
-                 (Dependency (..), PackageName, mkPackageName)
+                 (Dependency (..), ExeDependency (..), PackageName, mkPackageName)
 import           Distribution.System
                  (Arch (..), ClassificationStrictness (..), OS (..),
                  classifyArch, classifyOS)
@@ -115,6 +115,14 @@ instance Parsec Dependency where
         ver  <- parsec <|> pure anyVersion
         return (Dependency name ver)
 
+instance Parsec ExeDependency where
+    parsec = do
+        name <- lexemeParsec
+        _    <- P.char ':'
+        exe  <- P.munch1 isAlphaNum
+        ver  <- parsec <|> pure anyVersion
+        return (ExeDependency name exe ver)
+
 instance Parsec Version where
     parsec = mkVersion <$>
         P.sepBy1 P.integral (P.char '.')

Cabal/Distribution/Types/SetupBuildInfo.hs

@@ -19,6 +19,7 @@ import Distribution.Package
 
 data SetupBuildInfo = SetupBuildInfo {
         setupDepends        :: [Dependency],
+        setupTool           :: Maybe ExeDependency,
         defaultSetupDepends :: Bool
         -- ^ Is this a default 'custom-setup' section added by the cabal-install
         -- code (as opposed to user-provided)? This field is only used
@@ -30,9 +31,16 @@ data SetupBuildInfo = SetupBuildInfo {
 instance Binary SetupBuildInfo
 
 instance Monoid SetupBuildInfo where
-  mempty  = SetupBuildInfo [] False
+  mempty  = SetupBuildInfo [] Nothing False
   mappend = (<>)
 
 instance Semigroup SetupBuildInfo where
-  a <> b = SetupBuildInfo (setupDepends a <> setupDepends b)
-           (defaultSetupDepends a || defaultSetupDepends b)
+  a <> b = SetupBuildInfo {
+    setupDepends        = combine setupDepends,
+    setupTool           = combineMby setupTool,
+    defaultSetupDepends = defaultSetupDepends a || defaultSetupDepends b
+  }
+    where
+      combine    field = field a `mappend` field b
+      combineNub field = nub (combine field)
+      combineMby field = field b `mplus` field a