Install and use build tools first

Stackage/Build.hs

@@ -20,6 +20,8 @@ import           System.Directory     (createDirectoryIfMissing, canonicalizePat
 import           Distribution.Version    (thisVersion, withinRange)
 import Control.Exception (assert)
 import Data.Set (empty)
+import qualified Data.Map as Map
+import qualified Data.Set as Set
 
 defaultBuildSettings :: BuildSettings
 defaultBuildSettings = BuildSettings
@@ -76,7 +78,30 @@ build settings' = do
             | v `withinRange` vr -> return ()
             | otherwise -> error $ "Unsupported Cabal version: " ++ libVersion
 
-    ph <- withBinaryFile "build.log" WriteMode $ \handle ->
+    menv <- fmap Just $ getModifiedEnv settings
+    let runCabal args handle = runProcess "cabal" args Nothing menv Nothing (Just handle) (Just handle)
+
+    -- First install build tools so they can be used below.
+    case iiBuildTools ii of
+        [] -> putStrLn "No build tools required"
+        tools -> do
+            putStrLn $ "Installing the following build tools: " ++ unwords tools
+            ph1 <- withBinaryFile "build-tools.log" WriteMode $ \handle -> do
+                let args = addCabalArgs settings
+                         $ "install"
+                         : ("--cabal-lib-version=" ++ libVersion)
+                         : "--build-log=logs-tools/$pkg.log"
+                         : "-j"
+                         : iiBuildTools ii
+                hPutStrLn handle ("cabal " ++ unwords (map (\s -> "'" ++ s ++ "'") args))
+                runCabal args handle
+            ec1 <- waitForProcess ph1
+            unless (ec1 == ExitSuccess) $ do
+                putStrLn "Building of build tools failed, please see build-tools.log"
+                exitWith ec1
+            putStrLn "Build tools built"
+
+    ph <- withBinaryFile "build.log" WriteMode $ \handle -> do
         let args = addCabalArgs settings
                  $ "install"
                  : ("--cabal-lib-version=" ++ libVersion)
@@ -87,8 +112,8 @@ build settings' = do
                     , extraArgs settings
                     , iiPackageList ii
                     ]
-         in do hPutStrLn handle ("cabal " ++ unwords (map (\s -> "'" ++ s ++ "'") args))
-               runProcess "cabal" args Nothing Nothing Nothing (Just handle) (Just handle)
+        hPutStrLn handle ("cabal " ++ unwords (map (\s -> "'" ++ s ++ "'") args))
+        runCabal args handle
     ec <- waitForProcess ph
     unless (ec == ExitSuccess) $ do
         putStrLn "Build failed, please see build.log"
@@ -99,3 +124,20 @@ build settings' = do
 
     putStrLn "All test suites that were expected to pass did pass, building tarballs."
     makeTarballs ii
+
+-- | Get all of the build tools required.
+iiBuildTools :: InstallInfo -> [String]
+iiBuildTools InstallInfo { iiPackageDB = PackageDB m, iiPackages = packages } =
+    -- FIXME possible improvement: track the dependencies between the build
+    -- tools themselves, and install them in the correct order.
+    map unPackageName
+  $ filter (flip Map.member m)
+  $ Set.toList
+  $ Set.unions
+  $ map piBuildTools
+  $ Map.elems
+  $ Map.filterWithKey isSelected m
+  where
+    unPackageName (PackageName pn) = pn
+    isSelected name _ = name `Set.member` selected
+    selected = Set.fromList $ Map.keys packages

Stackage/LoadDatabase.hs

@@ -12,7 +12,7 @@ import           Distribution.PackageDescription       (condExecutables,
                                                         condLibrary,
                                                         condTestSuites,
                                                         condBenchmarks,
-                                                        condTreeConstraints, condTreeComponents, ConfVar (..), Condition(..), flagName, flagDefault, genPackageFlags)
+                                                        condTreeConstraints, condTreeComponents, ConfVar (..), Condition(..), flagName, flagDefault, genPackageFlags, allBuildInfo, packageDescription, buildTools, libBuildInfo, condTreeData, buildInfo, testBuildInfo, benchmarkBuildInfo)
 import           Distribution.PackageDescription.Parse (ParseResult (ParseOk),
                                                         parsePackageDescription)
 import           Distribution.Version                  (withinRange)
@@ -59,11 +59,12 @@ loadPackageDB core deps = do
                         _ ->
                             case Tar.entryContent e of
                                 Tar.NormalFile bs _ -> do
-                                    let (deps', hasTests) = parseDeps bs
+                                    let (deps', hasTests, buildTools) = parseDeps bs
                                     return $ mappend pdb $ PackageDB $ Map.singleton p PackageInfo
                                         { piVersion = v
                                         , piDeps = deps'
                                         , piHasTests = hasTests
+                                        , piBuildTools = buildTools
                                         }
                                 _ -> return pdb
 
@@ -74,9 +75,19 @@ loadPackageDB core deps = do
                 , mconcat $ map (go gpd . snd) $ condExecutables gpd
                 , mconcat $ map (go gpd . snd) $ condTestSuites gpd
                 , mconcat $ map (go gpd . snd) $ condBenchmarks gpd
-                ], not $ null $ condTestSuites gpd)
-            _ -> (mempty, defaultHasTestSuites)
+                ], not $ null $ condTestSuites gpd
+                , Set.fromList $ map depName $ allBuildInfo gpd)
+            _ -> (mempty, defaultHasTestSuites, Set.empty)
       where
+        allBuildInfo gpd = concat
+            [ maybe mempty (goBI libBuildInfo) $ condLibrary gpd
+            , concat $ map (goBI buildInfo . snd) $ condExecutables gpd
+            , concat $ map (goBI testBuildInfo . snd) $ condTestSuites gpd
+            , concat $ map (goBI benchmarkBuildInfo . snd) $ condBenchmarks gpd
+            ]
+          where
+            goBI f x = buildTools $ f $ condTreeData x
+        depName (Dependency p _) = p
         go gpd tree
             = Set.unions
             $ Set.fromList (map (\(Dependency p _) -> p) $ condTreeConstraints tree)

Stackage/Test.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 module Stackage.Test
     ( runTestSuites
@@ -32,18 +31,6 @@ runTestSuites settings ii = do
 
     hasTestSuites name = maybe defaultHasTestSuites piHasTests $ Map.lookup name pdb
 
--- | Separate for the PATH environment variable
-pathSep :: Char
-#ifdef mingw32_HOST_OS
-pathSep = ';'
-#else
-pathSep = ':'
-#endif
-
-fixEnv :: FilePath -> (String, String) -> (String, String)
-fixEnv bin (p@"PATH", x) = (p, bin ++ pathSep : x)
-fixEnv _ x = x
-
 data TestException = TestException
     deriving (Show, Typeable)
 instance Exception TestException
@@ -56,11 +43,11 @@ runTestSuite :: BuildSettings
              -> IO Bool
 runTestSuite settings testdir hasTestSuites prevPassed (packageName, (version, Maintainer maintainer)) = do
     -- Set up a new environment that includes the sandboxed bin folder in PATH.
-    env' <- getEnvironment
+    env' <- getModifiedEnv settings
     let menv addGPP
             = Just $ (if addGPP then (("GHC_PACKAGE_PATH", packageDir settings ++ ":"):) else id)
                    $ ("HASKELL_PACKAGE_SANDBOX", packageDir settings)
-                   : map (fixEnv $ binDir settings) env'
+                   : env'
 
     let runGen addGPP cmd args wdir handle = do
             ph <- runProcess cmd args (Just wdir) (menv addGPP) Nothing (Just handle) (Just handle)

Stackage/Types.hs

@@ -25,9 +25,10 @@ instance Monoid PackageDB where
             | otherwise = pi2
 
 data PackageInfo = PackageInfo
-    { piVersion  :: Version
-    , piDeps     :: Set PackageName
-    , piHasTests :: Bool
+    { piVersion    :: Version
+    , piDeps       :: Set PackageName
+    , piHasTests   :: Bool
+    , piBuildTools :: Set PackageName
     }
     deriving (Show, Eq, Ord)
 

Stackage/Util.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 module Stackage.Util where
 
 import qualified Codec.Archive.Tar       as Tar
@@ -14,6 +15,7 @@ import           System.Directory        (doesDirectoryExist,
                                           removeDirectoryRecursive)
 import           System.Directory        (getAppUserDataDirectory)
 import           System.FilePath         ((</>))
+import           System.Environment (getEnvironment)
 
 identsToRanges :: Set PackageIdentifier -> Map PackageName (VersionRange, Maintainer)
 identsToRanges =
@@ -84,3 +86,20 @@ addCabalArgs settings rest
     : ("--datadir=" ++ dataDir settings)
     : ("--docdir=" ++ docDir settings)
     : extraArgs settings ++ rest
+
+-- | Modified environment that adds our sandboxed bin folder to PATH.
+getModifiedEnv :: BuildSettings -> IO [(String, String)]
+getModifiedEnv settings = do
+    fmap (map $ fixEnv $ binDir settings) getEnvironment
+  where
+    fixEnv :: FilePath -> (String, String) -> (String, String)
+    fixEnv bin (p@"PATH", x) = (p, bin ++ pathSep : x)
+    fixEnv _ x = x
+
+    -- | Separate for the PATH environment variable
+    pathSep :: Char
+#ifdef mingw32_HOST_OS
+    pathSep = ';'
+#else
+    pathSep = ':'
+#endif