Abstract over make

So on FreeBSD we get gmake.

lib/GHCup.hs

@@ -140,12 +140,7 @@ installGHCBin bDls ver mpfReq = do
                               [rel|ghc-configure.log|]
                               (Just path)
                               Nothing
-    lEM $ liftIO $ execLogged [s|make|]
-                              True
-                              [[s|install|]]
-                              [rel|ghc-make.log|]
-                              (Just path)
-                              Nothing
+    lEM $ liftIO $ make [[s|install|]] (Just path)
     pure ()
 
 
@@ -541,20 +536,11 @@ GhcWithLlvmCodeGen = YES|]
     lift
       $ $(logInfo)
           [i|Building (this may take a while)... Run 'tail -f ~/.ghcup/logs/ghc-make.log' to see the progress.|]
-    lEM $ liftIO $ execLogged [s|make|]
-                              True
-                              (maybe [] (\j -> [[s|-j|] <> fS (show j)]) jobs)
-                              [rel|ghc-make.log|]
+    lEM $ liftIO $ make (maybe [] (\j -> [[s|-j|] <> fS (show j)]) jobs)
                         (Just workdir)
-                              Nothing
 
     lift $ $(logInfo) [i|Installing...|]
-    lEM $ liftIO $ execLogged [s|make|]
-                              True
-                              [[s|install|]]
-                              [rel|ghc-make.log|]
-                              (Just workdir)
-                              Nothing
+    lEM $ liftIO $ make [[s|install|]] (Just workdir)
 
   markSrcBuilt ghcdir workdir = do
     let dest = (ghcdir </> ghcUpSrcBuiltFile)

lib/GHCup/Utils.hs

@@ -44,7 +44,7 @@ import           Prelude                 hiding ( abs
                                                 )
 import           Safe
 import           System.IO.Error
-import           System.Posix.FilePath          ( takeFileName )
+import           System.Posix.FilePath          ( getSearchPath, takeFileName )
 import           System.Posix.Files.ByteString  ( readSymbolicLink )
 import           URI.ByteString
 
@@ -325,3 +325,12 @@ ghcToolFiles ver = do
 -- this GHC was built from source. It contains the build config.
 ghcUpSrcBuiltFile :: Path Rel
 ghcUpSrcBuiltFile = [rel|.ghcup_src_built|]
+
+
+-- | Calls gmake if it exists in PATH, otherwise make.
+make :: [ByteString] -> Maybe (Path Abs) -> IO (Either ProcessError ())
+make args workdir = do
+  spaths    <- catMaybes . fmap parseAbs <$> getSearchPath
+  has_gmake <- isJust <$> searchPath spaths [rel|gmake|]
+  let mymake = if has_gmake then [s|gmake|] else [s|make|]
+  execLogged mymake True args [rel|ghc-make.log|] workdir Nothing