Move `iserv` into `utils` and change package name from `iserv-bin` to `iserv`

This is done for consistency. We usually call the package file the same name the
folder has.  The move into `utils` is done so that we can move the library into
`libraries/iserv` and the proxy into `utils/iserv-proxy` and then break the
`iserv.cabal` apart.  This will make building the cross compiler with TH
simpler, because we can build the library and proxy as separate packages.

Test Plan: ./validate

Reviewers: bgamari, goldfire, erikd

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4436

1 files changed, 63 insertions, 0 deletions

diff --git a/utils/iserv/src/Main.hs b/utils/iserv/src/Main.hs
new file mode 100644
index 0000000000..858cee8e94
--- /dev/null
+++ b/utils/iserv/src/Main.hs
@@ -0,0 +1,63 @@
+{-# LANGUAGE CPP, GADTs #-}
+
+-- |
+-- The Remote GHCi server.
+--
+-- For details on Remote GHCi, see Note [Remote GHCi] in
+-- compiler/ghci/GHCi.hs.
+--
+module Main (main) where
+
+import Lib (serv)
+
+import GHCi.Message
+import GHCi.Signals
+import GHCi.Utils
+
+import Control.Exception
+import Control.Monad
+import Data.IORef
+import System.Environment
+import System.Exit
+import Text.Printf
+
+dieWithUsage :: IO a
+dieWithUsage = do
+    prog <- getProgName
+    die $ prog ++ ": " ++ msg
+  where
+#ifdef WINDOWS
+    msg = "usage: iserv <write-handle> <read-handle> [-v]"
+#else
+    msg = "usage: iserv <write-fd> <read-fd> [-v]"
+#endif
+
+main :: IO ()
+main = do
+  args <- getArgs
+  (wfd1, rfd2, rest) <-
+      case args of
+        arg0:arg1:rest -> do
+            let wfd1 = read arg0
+                rfd2 = read arg1
+            return (wfd1, rfd2, rest)
+        _ -> dieWithUsage
+
+  verbose <- case rest of
+    ["-v"] -> return True
+    []     -> return False
+    _      -> dieWithUsage
+  when verbose $
+    printf "GHC iserv starting (in: %d; out: %d)\n"
+      (fromIntegral rfd2 :: Int) (fromIntegral wfd1 :: Int)
+  inh  <- getGhcHandle rfd2
+  outh <- getGhcHandle wfd1
+  installSignalHandlers
+  lo_ref <- newIORef Nothing
+  let pipe = Pipe{pipeRead = inh, pipeWrite = outh, pipeLeftovers = lo_ref}
+  uninterruptibleMask $ serv verbose hook pipe
+
+  where hook = return -- empty hook
+    -- we cannot allow any async exceptions while communicating, because
+    -- we will lose sync in the protocol, hence uninterruptibleMask.
+