Suport using Stack's built-in GHC to build the helper

3 files changed, 46 insertions, 38 deletions

diff --git a/src/CabalHelper/Compiletime/Compile.hs b/src/CabalHelper/Compiletime/Compile.hs
index 3f8a771..431043b 100644
--- a/src/CabalHelper/Compiletime/Compile.hs
+++ b/src/CabalHelper/Compiletime/Compile.hs
@@ -326,9 +326,10 @@ cabalMinVersionMacro (Version (mj1:mj2:mi:_) _) =
 cabalMinVersionMacro _ =
     error "cabalMinVersionMacro: Version must have at least 3 components"
 
-invokeGhc :: Env => GhcInvocation -> IO (Either ExitCode FilePath)
+invokeGhc
+    :: (Verbose, CProgs) => GhcInvocation -> IO (Either ExitCode FilePath)
 invokeGhc GhcInvocation {..} = do
-    rv <- callProcessStderr' Nothing (ghcProgram ?progs) $ concat
+    rv <- callProcessStderr' Nothing (ghcProgram ?cprogs) $ concat
       [ [ "-outputdir", giOutDir
         , "-o", giOutput
         ]
@@ -364,7 +365,7 @@ exeName CabalVersion {cabalVersion} = intercalate "-"
     , "Cabal" ++ showVersion cabalVersion
     ]
 
-readProcess' :: Env => FilePath -> [String] -> String -> IO String
+readProcess' :: Verbose => FilePath -> [String] -> String -> IO String
 readProcess' exe args inp = do
   vLog $ intercalate " " $ map formatProcessArg (exe:args)
   outp <- readProcess exe args inp
@@ -372,7 +373,7 @@ readProcess' exe args inp = do
   return outp
 
 callProcessStderr'
-    :: Env => Maybe FilePath -> FilePath -> [String] -> IO ExitCode
+    :: Verbose => Maybe FilePath -> FilePath -> [String] -> IO ExitCode
 callProcessStderr' mwd exe args = do
   let cd = case mwd of
              Nothing -> []; Just wd -> [ "cd", formatProcessArg wd++";" ]
@@ -381,7 +382,7 @@ callProcessStderr' mwd exe args = do
                                                 , cwd = mwd }
   waitForProcess h
 
-callProcessStderr :: Env => Maybe FilePath -> FilePath -> [String] -> IO ()
+callProcessStderr :: Verbose => Maybe FilePath -> FilePath -> [String] -> IO ()
 callProcessStderr mwd exe args = do
   rv <- callProcessStderr' mwd exe args
   case rv of
@@ -482,9 +483,9 @@ runCabalInstall (PackageDbDir db) (CabalSourceDir srcdir) ever = do
 
 withGHCProgramOptions :: Env => [String]
 withGHCProgramOptions =
-    concat [ [ "--with-ghc=" ++ oGhcProgram ]
-           , if oGhcProgram /= ghcPkgProgram defaultPrograms
-               then [ "--with-ghc-pkg=" ++ oGhcPkgProgram ]
+    concat [ [ "--with-ghc=" ++ ghcProgram ?cprogs ]
+           , if ghcProgram ?cprogs /= ghcPkgProgram defaultCompPrograms
+               then [ "--with-ghc-pkg=" ++ ghcPkgProgram ?cprogs ]
                else []
            ]
 
@@ -533,7 +534,7 @@ compileSetupHs db srcdir = do
 
       file = srcdir </> "Setup"
 
-  callProcessStderr (Just srcdir) oGhcProgram $ concat
+  callProcessStderr (Just srcdir) (ghcProgram ?cprogs) $ concat
     [ [ "--make"
       , "-package-conf", db
       ]
@@ -691,7 +692,7 @@ listCabalVersions' mdb = do
               args = ["list", "--simple-output", "Cabal"] ++ maybeToList mdbopt
 
           catMaybes . map (fmap snd . parsePkgId . fromString) . words
-                   <$> readProcess' oGhcPkgProgram args ""
+                   <$> readProcess' (ghcProgram ?cprogs) args ""
 
 cabalVersionExistsInPkgDb :: Env => Version -> PackageDbDir -> IO Bool
 cabalVersionExistsInPkgDb cabalVer db@(PackageDbDir db_path) = do
@@ -702,14 +703,14 @@ cabalVersionExistsInPkgDb cabalVer db@(PackageDbDir db_path) = do
       vers <- listCabalVersions' (Just db)
       return $ cabalVer `elem` vers)
 
-ghcVersion :: Env => IO Version
+ghcVersion :: (Verbose, CProgs) => IO Version
 ghcVersion = do
-    parseVer . trim <$> readProcess' oGhcProgram ["--numeric-version"] ""
+  parseVer . trim <$> readProcess' (ghcProgram ?cprogs) ["--numeric-version"] ""
 
-ghcPkgVersion :: Env => IO Version
+ghcPkgVersion :: (Verbose, CProgs) => IO Version
 ghcPkgVersion =
   parseVer . trim . dropWhile (not . isDigit)
-    <$> readProcess' oGhcPkgProgram ["--version"] ""
+    <$> readProcess' (ghcPkgProgram ?cprogs) ["--version"] ""
 
 newtype CabalInstallVersion = CabalInstallVersion { cabalInstallVer :: Version }
 cabalInstallVersion :: Env => IO CabalInstallVersion
@@ -717,15 +718,15 @@ cabalInstallVersion = do
   CabalInstallVersion . parseVer . trim
     <$> readProcess' oCabalProgram ["--numeric-version"] ""
 
-createPkgDb :: Env => CabalVersion -> IO PackageDbDir
+createPkgDb :: (Verbose, CProgs) => CabalVersion -> IO PackageDbDir
 createPkgDb cabalVer = do
   db@(PackageDbDir db_path) <- getPrivateCabalPkgDb cabalVer
   exists <- doesDirectoryExist db_path
   when (not exists) $
-       callProcessStderr Nothing oGhcPkgProgram ["init", db_path]
+       callProcessStderr Nothing (ghcPkgProgram ?cprogs) ["init", db_path]
   return db
 
-getPrivateCabalPkgDb :: Env => CabalVersion -> IO PackageDbDir
+getPrivateCabalPkgDb :: (Verbose, CProgs) => CabalVersion -> IO PackageDbDir
 getPrivateCabalPkgDb cabalVer = do
   appdir <- appCacheDir
   ghcVer <- ghcVersion
diff --git a/src/CabalHelper/Compiletime/Program/Stack.hs b/src/CabalHelper/Compiletime/Program/Stack.hs
index e7f280d..322ccaf 100644
--- a/src/CabalHelper/Compiletime/Program/Stack.hs
+++ b/src/CabalHelper/Compiletime/Program/Stack.hs
@@ -20,7 +20,7 @@ Description : Stack program interface
 License     : GPL-3
 -}
 
-{-# LANGUAGE GADTs, DataKinds #-}
+{-# LANGUAGE NamedFieldPuns, GADTs, DataKinds #-}
 
 module CabalHelper.Compiletime.Program.Stack where
 
@@ -64,6 +64,7 @@ projPaths qe@QueryEnv {qeProjLoc=ProjLocStackDir projdir} = do
     { sppGlobalPkgDb = PackageDbDir $ look "global-pkg-db:"
     , sppSnapPkgDb   = PackageDbDir $ look "snapshot-pkg-db:"
     , sppLocalPkgDb  = PackageDbDir $ look "local-pkg-db:"
+    , sppCompExe     = look "compiler-exe:"
     }
 
 paths :: QueryEnvI c 'Stack
@@ -85,3 +86,7 @@ listPackageCabalFiles qe@QueryEnv{qeProjLoc=ProjLocStackDir projdir} = do
 workdirArg :: QueryEnvI c 'Stack -> [String]
 workdirArg QueryEnv{qeDistDir=DistDirStack mworkdir} =
   maybeToList $ ("--work-dir="++) . unRelativePath <$> mworkdir
+
+patchCompPrograms :: StackProjPaths -> CompPrograms -> CompPrograms
+patchCompPrograms StackProjPaths{sppCompExe} cprogs =
+  cprogs { ghcProgram = sppCompExe }
diff --git a/src/CabalHelper/Compiletime/Types.hs b/src/CabalHelper/Compiletime/Types.hs
index cc8561f..5ae712a 100644
--- a/src/CabalHelper/Compiletime/Types.hs
+++ b/src/CabalHelper/Compiletime/Types.hs
@@ -101,7 +101,10 @@ data QueryEnvI cache (proj_type :: ProjType) = QueryEnv
     -- processes. Useful if you need to, for example, redirect standard error
     -- output away from the user\'s terminal.
 
-    , qePrograms    :: Programs
+    , qePrograms     :: !Programs
+    -- ^ Field accessor for 'QueryEnv'.
+
+    , qeCompPrograms :: !CompPrograms
     -- ^ Field accessor for 'QueryEnv'.
 
     , qeProjLoc      :: !(ProjLoc proj_type)
@@ -232,15 +235,16 @@ data StackProjPaths = StackProjPaths
     { sppGlobalPkgDb :: !PackageDbDir
     , sppSnapPkgDb   :: !PackageDbDir
     , sppLocalPkgDb  :: !PackageDbDir
+    , sppCompExe     :: !FilePath
     }
 
+
+-- Beware: GHC 8.0.2 doesn't like these being recursively defined for some
+-- reason so just keep them unrolled.
 type Verbose = (?verbose :: Bool)
-type Progs = (?progs :: Programs)
--- TODO: rname to `CompEnv` or something
-type Env =
-    ( ?verbose :: Bool
-    , ?progs   :: Programs
-    )
+type Env     = (?cprogs :: CompPrograms, ?progs :: Programs, ?verbose :: Bool)
+type Progs   = (?cprogs :: CompPrograms, ?progs :: Programs)
+type CProgs  = (?cprogs :: CompPrograms)
 
 -- | Configurable paths to various programs we use.
 data Programs = Programs {
@@ -248,21 +252,25 @@ data Programs = Programs {
       cabalProgram  :: FilePath,
 
       -- | The path to the @stack@ program.
-      stackProgram  :: FilePath,
+      stackProgram  :: FilePath
+    } deriving (Eq, Ord, Show, Read, Generic, Typeable)
 
-      -- | The path to the @ghc@ program.
-      ghcProgram    :: FilePath,
+data CompPrograms = CompPrograms
+    { ghcProgram    :: FilePath
+    -- ^ The path to the @ghc@ program.
 
-      -- | The path to the @ghc-pkg@ program. If
-      -- not changed it will be derived from the path to 'ghcProgram'.
-      ghcPkgProgram :: FilePath
+    , ghcPkgProgram :: FilePath
+    -- ^ The path to the @ghc-pkg@ program. If not changed it will be derived
+    -- from the path to 'ghcProgram'.
     } deriving (Eq, Ord, Show, Read, Generic, Typeable)
 
 -- | By default all programs use their unqualified names, i.e. they will be
 -- searched for on @PATH@.
 defaultPrograms :: Programs
-defaultPrograms = Programs "cabal" "stack" "ghc" "ghc-pkg"
+defaultPrograms = Programs "cabal" "stack"
 
+defaultCompPrograms :: CompPrograms
+defaultCompPrograms = CompPrograms "ghc" "ghc-pkg"
 
 data CompileOptions = CompileOptions
     { oVerbose       :: Bool
@@ -274,12 +282,6 @@ data CompileOptions = CompileOptions
 oCabalProgram :: Env => FilePath
 oCabalProgram = cabalProgram ?progs
 
-oGhcProgram :: Env => FilePath
-oGhcProgram = ghcProgram ?progs
-
-oGhcPkgProgram :: Env => FilePath
-oGhcPkgProgram = ghcPkgProgram ?progs
-
 defaultCompileOptions :: CompileOptions
 defaultCompileOptions =
     CompileOptions False Nothing Nothing defaultPrograms