Merge libiserv with ghci

`libiserv` serves no purpose. As it depends on `ghci` and doesn't have
more dependencies than the `ghci` package, its code could live in the
`ghci` package too.

This commit also moves most of the code from the `iserv` program into
the `ghci` package as well so that it can be reused. This is especially
useful for the implementation of TH for the JS backend (#22261, !9779).

21 files changed, 104 insertions, 251 deletions

diff --git a/CODEOWNERS b/CODEOWNERS
index f915a57510..4bb5ca1bf8 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -59,7 +59,6 @@
 /libraries/template-haskell/      @rae
 
 [Internal utilities and libraries]
-/libraries/libiserv/              @angerman @simonmar
 /utils/iserv-proxy/               @angerman @simonmar
 /utils/iserv/                     @angerman @simonmar
 /utils/fs/                        @Phyx
diff --git a/cabal.project-reinstall b/cabal.project-reinstall
index 181efe48a6..6a380bb94c 100644
--- a/cabal.project-reinstall
+++ b/cabal.project-reinstall
@@ -24,7 +24,6 @@ packages: ./compiler
           ./libraries/directory
           ./libraries/hpc
           -- ./libraries/integer-gmp
-          ./libraries/libiserv/
           ./libraries/mtl/
           ./libraries/parsec/
           -- ./libraries/pretty/
diff --git a/docs/users_guide/9.6.1-notes.rst b/docs/users_guide/9.6.1-notes.rst
index 646ea43c1c..38d52b49c9 100644
--- a/docs/users_guide/9.6.1-notes.rst
+++ b/docs/users_guide/9.6.1-notes.rst
@@ -254,7 +254,6 @@ for further change information.
     libraries/haskeline/haskeline.cabal:     Dependency of ``ghci`` executable
     libraries/hpc/hpc.cabal:                 Dependency of ``hpc`` executable
     libraries/integer-gmp/integer-gmp.cabal: Core library
-    libraries/libiserv/libiserv.cabal:       Internal compiler library
     libraries/mtl/mtl.cabal:                 Dependency of ``Cabal`` library
     libraries/parsec/parsec.cabal:           Dependency of ``Cabal`` library
     libraries/pretty/pretty.cabal:           Dependency of ``ghc`` library
diff --git a/docs/users_guide/9.8.1-notes.rst b/docs/users_guide/9.8.1-notes.rst
index 14c6d5bff6..f836f62320 100644
--- a/docs/users_guide/9.8.1-notes.rst
+++ b/docs/users_guide/9.8.1-notes.rst
@@ -75,7 +75,6 @@ for further change information.
     libraries/haskeline/haskeline.cabal:     Dependency of ``ghci`` executable
     libraries/hpc/hpc.cabal:                 Dependency of ``hpc`` executable
     libraries/integer-gmp/integer-gmp.cabal: Core library
-    libraries/libiserv/libiserv.cabal:       Internal compiler library
     libraries/mtl/mtl.cabal:                 Dependency of ``Cabal`` library
     libraries/parsec/parsec.cabal:           Dependency of ``Cabal`` library
     libraries/pretty/pretty.cabal:           Dependency of ``ghc`` library
diff --git a/hadrian/src/Packages.hs b/hadrian/src/Packages.hs
index 449004ed92..6dbeb6ed14 100644
--- a/hadrian/src/Packages.hs
+++ b/hadrian/src/Packages.hs
@@ -7,7 +7,7 @@ module Packages (
     exceptions, filepath, genapply, genprimopcode, ghc, ghcBignum, ghcBoot, ghcBootTh,
     ghcCompact, ghcConfig, ghcHeap, ghci, ghciWrapper, ghcPkg, ghcPrim, haddock, haskeline,
     hsc2hs, hp2ps, hpc, hpcBin, integerGmp, integerSimple, iserv, iservProxy,
-    libffi, libiserv, mtl, parsec, pretty, primitive, process, remoteIserv, rts,
+    libffi, mtl, parsec, pretty, primitive, process, remoteIserv, rts,
     runGhc, stm, templateHaskell, terminfo, text, time, timeout, touchy,
     transformers, unlit, unix, win32, xhtml,
     lintersCommon, lintNotes, lintCommitMsg, lintSubmoduleRefs, lintWhitespace,
@@ -38,7 +38,7 @@ ghcPackages =
     , compareSizes, compiler, containers, deepseq, deriveConstants, directory
     , exceptions, filepath, genapply, genprimopcode, ghc, ghcBignum, ghcBoot, ghcBootTh
     , ghcCompact, ghcConfig, ghcHeap, ghci, ghciWrapper, ghcPkg, ghcPrim, haddock, haskeline, hsc2hs
-    , hp2ps, hpc, hpcBin, integerGmp, integerSimple, iserv, libffi, libiserv, mtl
+    , hp2ps, hpc, hpcBin, integerGmp, integerSimple, iserv, libffi, mtl
     , parsec, pretty, process, rts, runGhc, stm, templateHaskell
     , terminfo, text, time, touchy, transformers, unlit, unix, win32, xhtml
     , timeout
@@ -54,7 +54,7 @@ array, base, binary, bytestring, cabalSyntax, cabal, checkPpr, checkExact, count
   compareSizes, compiler, containers, deepseq, deriveConstants, directory,
   exceptions, filepath, genapply, genprimopcode, ghc, ghcBignum, ghcBoot, ghcBootTh,
   ghcCompact, ghcConfig, ghcHeap, ghci, ghciWrapper, ghcPkg, ghcPrim, haddock, haskeline, hsc2hs,
-  hp2ps, hpc, hpcBin, integerGmp, integerSimple, iserv, iservProxy, remoteIserv, libffi, libiserv, mtl,
+  hp2ps, hpc, hpcBin, integerGmp, integerSimple, iserv, iservProxy, remoteIserv, libffi, mtl,
   parsec, pretty, primitive, process, rts, runGhc, stm, templateHaskell,
   terminfo, text, time, touchy, transformers, unlit, unix, win32, xhtml,
   timeout,
@@ -102,7 +102,6 @@ integerSimple       = lib  "integer-simple"
 iserv               = util "iserv"
 iservProxy          = util "iserv-proxy"
 libffi              = top  "libffi"
-libiserv            = lib  "libiserv"
 mtl                 = lib  "mtl"
 parsec              = lib  "parsec"
 pretty              = lib  "pretty"
diff --git a/hadrian/src/Rules/Documentation.hs b/hadrian/src/Rules/Documentation.hs
index 27aece61d2..c982642b32 100644
--- a/hadrian/src/Rules/Documentation.hs
+++ b/hadrian/src/Rules/Documentation.hs
@@ -76,7 +76,6 @@ needDocDeps = do
             [ ghcBoot
             , ghcBootTh
             , ghci
-            , libiserv
             , compiler
             , ghcHeap
             , templateHaskell
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index e6e5ecd96b..fbd6f8d9aa 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -326,7 +326,6 @@ templateRules = do
   templateRule "driver/ghci/ghci-wrapper.cabal" $ projectVersion
   templateRule "ghc/ghc-bin.cabal" $ projectVersion
   templateRule "utils/iserv/iserv.cabal" $ projectVersion
-  templateRule "utils/iserv-proxy/iserv-proxy.cabal" $ projectVersion
   templateRule "utils/remote-iserv/remote-iserv.cabal" $ projectVersion
   templateRule "utils/runghc/runghc.cabal" $ projectVersion
   templateRule "libraries/ghc-boot/ghc-boot.cabal" $ projectVersion
@@ -334,7 +333,6 @@ templateRules = do
   templateRule "libraries/ghci/ghci.cabal" $ projectVersion
   templateRule "libraries/ghc-heap/ghc-heap.cabal" $ projectVersion
   templateRule "utils/ghc-pkg/ghc-pkg.cabal" $ projectVersion
-  templateRule "libraries/libiserv/libiserv.cabal" $ projectVersion
   templateRule "libraries/template-haskell/template-haskell.cabal" $ projectVersion
   templateRule "libraries/prologue.txt" $ packageVersions
 
diff --git a/hadrian/src/Settings/Default.hs b/hadrian/src/Settings/Default.hs
index 3781c3d490..5996924096 100644
--- a/hadrian/src/Settings/Default.hs
+++ b/hadrian/src/Settings/Default.hs
@@ -151,7 +151,6 @@ stage1Packages = do
         [ haddock
         , hpcBin
         , iserv
-        , libiserv
         , runGhc
         ]
       , when (winTarget && not cross)
diff --git a/hadrian/src/Settings/Packages.hs b/hadrian/src/Settings/Packages.hs
index 39ba685255..e2afd72ee5 100644
--- a/hadrian/src/Settings/Packages.hs
+++ b/hadrian/src/Settings/Packages.hs
@@ -116,9 +116,9 @@ packageArgs = do
           [
           -- The use case here is that we want to build @iserv-proxy@ for the
           -- cross compiler. That one needs to be compiled by the bootstrap
-          -- compiler as it needs to run on the host. Hence @libiserv@ needs
-          -- @GHCi.TH@, @GHCi.Message@ and @GHCi.Run@ from @ghci@. And those are
-          -- behind the @-finternal-interpreter@ flag.
+          -- compiler as it needs to run on the host. Hence @iserv@ needs
+          -- @GHCi.TH@, @GHCi.Message@, @GHCi.Run@, and @GHCi.Server@ from
+          -- @ghci@. And those are behind the @-finternal-interpreter@ flag.
           --
           -- But it may not build if we have made some changes to ghci's
           -- dependencies (see #16051).
diff --git a/libraries/libiserv/src/IServ.hs b/libraries/ghci/GHCi/Server.hs
index 6361a8c04c..f46060a01c 100644
--- a/libraries/libiserv/src/IServ.hs
+++ b/libraries/ghci/GHCi/Server.hs
@@ -1,17 +1,27 @@
-{-# LANGUAGE RankNTypes, RecordWildCards, GADTs, ScopedTypeVariables #-}
-module IServ (serv) where
+{-# LANGUAGE CPP, RankNTypes, RecordWildCards, GADTs, ScopedTypeVariables #-}
+module GHCi.Server
+  ( serv
+  , defaultServer
+  )
+where
 
+import Prelude
 import GHCi.Run
 import GHCi.TH
 import GHCi.Message
+import GHCi.Signals
+import GHCi.Utils
 
 import Control.DeepSeq
 import Control.Exception
 import Control.Monad
+import Control.Concurrent (threadDelay)
 import Data.Binary
+import Data.IORef
 
 import Text.Printf
-import System.Environment (getProgName)
+import System.Environment (getProgName, getArgs)
+import System.Exit
 
 type MessageHook = Msg -> IO Msg
 
@@ -84,3 +94,55 @@ serv verbose hook pipe restore = loop
       Left UserInterrupt -> return () >> discardCtrlC
       Left e -> throwIO e
       _ -> return ()
+
+-- | Default server
+defaultServer :: IO ()
+defaultServer = do
+  args <- getArgs
+  (outh, inh, rest) <-
+      case args of
+        arg0:arg1:rest -> do
+            inh  <- readGhcHandle arg1
+            outh <- readGhcHandle arg0
+            return (outh, inh, rest)
+        _ -> dieWithUsage
+
+  (verbose, rest') <- case rest of
+    "-v":rest' -> return (True, rest')
+    _ -> return (False, rest)
+
+  (wait, rest'') <- case rest' of
+    "-wait":rest'' -> return (True, rest'')
+    _ -> return (False, rest')
+
+  unless (null rest'') $
+    dieWithUsage
+
+  when verbose $
+    printf "GHC iserv starting (in: %s; out: %s)\n" (show inh) (show outh)
+  installSignalHandlers
+  lo_ref <- newIORef Nothing
+  let pipe = Pipe{pipeRead = inh, pipeWrite = outh, pipeLeftovers = lo_ref}
+
+  when wait $ do
+    when verbose $
+      putStrLn "Waiting 3s"
+    threadDelay 3000000
+
+  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.
+
+dieWithUsage :: IO a
+dieWithUsage = do
+    prog <- getProgName
+    die $ prog ++ ": " ++ msg
+  where
+#if defined(WINDOWS)
+    msg = "usage: iserv <write-handle> <read-handle> [-v]"
+#else
+    msg = "usage: iserv <write-fd> <read-fd> [-v]"
+#endif
+
diff --git a/libraries/libiserv/src/GHCi/Utils.hsc b/libraries/ghci/GHCi/Utils.hsc
index 6b6613ad1b..43ab4a8550 100644
--- a/libraries/libiserv/src/GHCi/Utils.hsc
+++ b/libraries/ghci/GHCi/Utils.hsc
@@ -1,12 +1,15 @@
 {-# LANGUAGE CPP #-}
 module GHCi.Utils
-    ( getGhcHandle
-    ) where
+  ( getGhcHandle
+  , readGhcHandle
+  )
+where
 
+import Prelude
 import Foreign.C
 import GHC.IO.Handle (Handle())
 #if defined(mingw32_HOST_OS)
-import Foreign.Ptr (ptrToIntPtr)
+import Foreign.Ptr (ptrToIntPtr,wordPtrToPtr)
 import GHC.IO (onException)
 import GHC.IO.Handle.FD (fdToHandle)
 import GHC.Windows (HANDLE)
@@ -16,12 +19,13 @@ import GHC.IO.Device as IODevice
 import GHC.IO.Encoding (getLocaleEncoding)
 import GHC.IO.IOMode
 import GHC.IO.Windows.Handle (fromHANDLE, Io(), NativeHandle())
+
+#include <fcntl.h>     /* for _O_BINARY */
+
 #else
 import System.Posix
 #endif
 
-#include <fcntl.h>     /* for _O_BINARY */
-
 -- | Gets a GHC Handle File description from the given OS Handle or POSIX fd.
 
 #if defined(mingw32_HOST_OS)
@@ -48,3 +52,20 @@ foreign import ccall "io.h _open_osfhandle" _open_osfhandle ::
 getGhcHandle :: CInt -> IO Handle
 getGhcHandle fd     = fdToHandle $ Fd fd
 #endif
+
+-- | Read a handle passed on the command-line and prepare it to be used with the IO manager
+readGhcHandle :: String -> IO Handle
+readGhcHandle s = do
+#if defined(mingw32_HOST_OS)
+  let fd = wordPtrToPtr (Prelude.read s)
+# if defined(__IO_MANAGER_WINIO__)
+  -- register the handles we received with
+  -- our I/O manager otherwise we can't use
+  -- them correctly.
+  return () <!> associateHandle' fd
+# endif
+#else
+  let fd = Prelude.read s
+#endif
+  getGhcHandle fd
+
diff --git a/libraries/ghci/ghci.cabal.in b/libraries/ghci/ghci.cabal.in
index 78466a814a..700b7d62ea 100644
--- a/libraries/ghci/ghci.cabal.in
+++ b/libraries/ghci/ghci.cabal.in
@@ -57,6 +57,7 @@ library
             GHCi.Signals
             GHCi.StaticPtrTable
             GHCi.TH
+            GHCi.Server
 
     exposed-modules:
         GHCi.BreakArray
@@ -66,6 +67,7 @@ library
         GHCi.RemoteTypes
         GHCi.FFI
         GHCi.TH.Binary
+        GHCi.Utils
 
     Build-Depends:
         rts,
diff --git a/libraries/libiserv/.gitignore b/libraries/libiserv/.gitignore
deleted file mode 100644
index 89cf73d0b3..0000000000
--- a/libraries/libiserv/.gitignore
+++ /dev/null
@@ -1,4 +0,0 @@
-GNUmakefile
-/dist-install/
-/dist/
-ghc.mk
diff --git a/libraries/libiserv/LICENSE b/libraries/libiserv/LICENSE
deleted file mode 100644
index fe00a83ea9..0000000000
--- a/libraries/libiserv/LICENSE
+++ /dev/null
@@ -1,62 +0,0 @@
-This library (libraries/ghc-prim) is derived from code from several
-sources: 
-
-  * Code from the GHC project which is largely (c) The University of
-    Glasgow, and distributable under a BSD-style license (see below),
-
-  * Code from the Haskell 98 Report which is (c) Simon Peyton Jones
-    and freely redistributable (but see the full license for
-    restrictions).
-
-The full text of these licenses is reproduced below.  All of the
-licenses are BSD-style or compatible.
-
------------------------------------------------------------------------------
-
-The Glasgow Haskell Compiler License
-
-Copyright 2004, The University Court of the University of Glasgow. 
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-- Redistributions of source code must retain the above copyright notice,
-this list of conditions and the following disclaimer.
- 
-- Redistributions in binary form must reproduce the above copyright notice,
-this list of conditions and the following disclaimer in the documentation
-and/or other materials provided with the distribution.
- 
-- Neither name of the University nor the names of its contributors may be
-used to endorse or promote products derived from this software without
-specific prior written permission. 
-
-THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY COURT OF THE UNIVERSITY OF
-GLASGOW AND THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
-INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
-FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
-UNIVERSITY COURT OF THE UNIVERSITY OF GLASGOW OR THE CONTRIBUTORS BE LIABLE
-FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
-DAMAGE.
-
------------------------------------------------------------------------------
-
-Code derived from the document "Report on the Programming Language
-Haskell 98", is distributed under the following license:
-
-  Copyright (c) 2002 Simon Peyton Jones
-
-  The authors intend this Report to belong to the entire Haskell
-  community, and so we grant permission to copy and distribute it for
-  any purpose, provided that it is reproduced in its entirety,
-  including this Notice.  Modified versions of this Report may also be
-  copied and distributed for any purpose, provided that the modified
-  version is clearly presented as such, and that it does not claim to
-  be a definition of the Haskell 98 Language.
-
diff --git a/libraries/libiserv/Makefile b/libraries/libiserv/Makefile
deleted file mode 100644
index 88656e7853..0000000000
--- a/libraries/libiserv/Makefile
+++ /dev/null
@@ -1,15 +0,0 @@
-# -----------------------------------------------------------------------------
-#
-# (c) 2009 The University of Glasgow
-#
-# This file is part of the GHC build system.
-#
-# To understand how the build system works and how to modify it, see
-#      https://gitlab.haskell.org/ghc/ghc/wikis/building/architecture
-#      https://gitlab.haskell.org/ghc/ghc/wikis/building/modifying
-#
-# -----------------------------------------------------------------------------
-
-dir = iserv
-TOP = ..
-include $(TOP)/mk/sub-makefile.mk
diff --git a/libraries/libiserv/cbits/iservmain.c b/libraries/libiserv/cbits/iservmain.c
deleted file mode 100644
index 5c88018d6b..0000000000
--- a/libraries/libiserv/cbits/iservmain.c
+++ /dev/null
@@ -1,17 +0,0 @@
-#include <rts/PosixSource.h>
-#include <Rts.h>
-
-#include <HsFFI.h>
-
-int main (int argc, char *argv[])
-{
-    RtsConfig conf = defaultRtsConfig;
-
-    // We never know what symbols GHC will look up in the future, so
-    // we must retain CAFs for running interpreted code.
-    conf.keep_cafs = 1;
-
-    conf.rts_opts_enabled = RtsOptsAll;
-    extern StgClosure ZCMain_main_closure;
-    hs_main(argc, argv, &ZCMain_main_closure, conf);
-}
diff --git a/libraries/libiserv/libiserv.cabal.in b/libraries/libiserv/libiserv.cabal.in
deleted file mode 100644
index 6f13a3da42..0000000000
--- a/libraries/libiserv/libiserv.cabal.in
+++ /dev/null
@@ -1,37 +0,0 @@
--- WARNING: libiserv.cabal is automatically generated from libiserv.cabal.in by
--- ../../configure.  Make sure you are editing libiserv.cabal.in, not
--- libiserv.cabal.
-
-Name: libiserv
-Version: @ProjectVersionMunged@
-Copyright: XXX
-License: BSD3
-License-File: LICENSE
-Author: XXX
-Maintainer: XXX
-Synopsis: Provides shared functionality between iserv and iserv-proxy.
-Description: Provides shared functionality between iserv and iserv-proxy.
-Category: Development
-build-type: Simple
-cabal-version: >=1.10
-
-Flag network
-    Description:   Build libiserv with over-the-network support
-    Default:       False
-
-Library
-    Default-Language: Haskell2010
-    Hs-Source-Dirs: src
-    Exposed-Modules: IServ
-                   , GHCi.Utils
-    Build-Depends: base       >= 4   && < 5,
-                   binary     >= 0.7 && < 0.11,
-                   bytestring >= 0.10 && < 0.12,
-                   containers >= 0.5 && < 0.7,
-                   deepseq    >= 1.4 && < 1.5,
-                   ghci       == @ProjectVersionMunged@
-
-    if os(windows)
-       Cpp-Options: -DWINDOWS
-   else
-       Build-Depends: unix   >= 2.7 && < 2.9
diff --git a/packages b/packages
index f9c798fc6e..2396bfdd74 100644
--- a/packages
+++ b/packages
@@ -52,7 +52,6 @@ libraries/directory          -           -                               ssh://g
 libraries/filepath           -           -                               ssh://git@github.com/haskell/filepath.git
 libraries/haskeline          -           -                               https://github.com/judah/haskeline.git
 libraries/hpc                -           -                               -
-libraries/libiserv           -           -                               -
 libraries/mtl                -           -                               https://github.com/haskell/mtl.git
 libraries/parsec             -           -                               https://github.com/haskell/parsec.git
 libraries/pretty             -           -                               https://github.com/haskell/pretty.git
diff --git a/utils/iserv/iserv.cabal.in b/utils/iserv/iserv.cabal.in
index 46a0357a63..2460963d8c 100644
--- a/utils/iserv/iserv.cabal.in
+++ b/utils/iserv/iserv.cabal.in
@@ -18,9 +18,6 @@ Description:
   compiling Template Haskell, by spawning a separate delegate (so
   called runner on the javascript vm) and evaluating the splices
   there.
-  .
-  To use iserv with cross compilers, please see @libraries/libiserv@
-  and @utils/iserv-proxy@.
 
 Category: Development
 build-type: Simple
@@ -39,8 +36,7 @@ Executable iserv
                    bytestring >= 0.10 && < 0.12,
                    containers >= 0.5 && < 0.7,
                    deepseq    >= 1.4 && < 1.5,
-                   ghci       == @ProjectVersionMunged@,
-                   libiserv   == @ProjectVersionMunged@
+                   ghci       == @ProjectVersionMunged@
 
     if os(windows)
         Cpp-Options: -DWINDOWS
diff --git a/utils/iserv/src/Main.hs b/utils/iserv/src/Main.hs
index 4c622f85a9..c455ea1f01 100644
--- a/utils/iserv/src/Main.hs
+++ b/utils/iserv/src/Main.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP, GADTs #-}
-
 -- |
 -- The Remote GHCi server.
 --
@@ -8,88 +6,7 @@
 --
 module Main (main) where
 
-import IServ (serv)
-
-import GHCi.Message
-import GHCi.Signals
-import GHCi.Utils
-
-import Control.Exception
-import Control.Concurrent (threadDelay)
-import Control.Monad
-import Data.IORef
-import System.Environment
-import System.Exit
-import Text.Printf
-#if defined(WINDOWS)
-import Foreign.Ptr (wordPtrToPtr)
-# if defined(__IO_MANAGER_WINIO__)
-import GHC.IO.SubSystem ((<!>))
-import GHC.Event.Windows (associateHandle')
-# endif
-#endif
-
-dieWithUsage :: IO a
-dieWithUsage = do
-    prog <- getProgName
-    die $ prog ++ ": " ++ msg
-  where
-#if defined(WINDOWS)
-    msg = "usage: iserv <write-handle> <read-handle> [-v]"
-#else
-    msg = "usage: iserv <write-fd> <read-fd> [-v]"
-#endif
+import GHCi.Server (defaultServer)
 
 main :: IO ()
-main = do
-  args <- getArgs
-  (outh, inh, rest) <-
-      case args of
-        arg0:arg1:rest -> do
-#if defined(WINDOWS)
-            let wfd1 = wordPtrToPtr (read arg0)
-                rfd2 = wordPtrToPtr (read arg1)
-# if defined(__IO_MANAGER_WINIO__)
-            -- register the handles we received with
-            -- our I/O manager otherwise we can't use
-            -- them correctly.
-            return () <!> (do
-              associateHandle' wfd1
-              associateHandle' rfd2)
-# endif
-#else
-            let wfd1 = read arg0
-                rfd2 = read arg1
-#endif
-            inh  <- getGhcHandle rfd2
-            outh <- getGhcHandle wfd1
-            return (outh, inh, rest)
-        _ -> dieWithUsage
-
-  (verbose, rest') <- case rest of
-    "-v":rest' -> return (True, rest')
-    _ -> return (False, rest)
-
-  (wait, rest'') <- case rest' of
-    "-wait":rest'' -> return (True, rest'')
-    _ -> return (False, rest')
-
-  unless (null rest'') $
-    dieWithUsage
-
-  when verbose $
-    printf "GHC iserv starting (in: %s; out: %s)\n" (show inh) (show outh)
-  installSignalHandlers
-  lo_ref <- newIORef Nothing
-  let pipe = Pipe{pipeRead = inh, pipeWrite = outh, pipeLeftovers = lo_ref}
-
-  when wait $ do
-    when verbose $
-      putStrLn "Waiting 3s"
-    threadDelay 3000000
-
-  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.
+main = defaultServer
diff --git a/utils/remote-iserv/remote-iserv.cabal.in b/utils/remote-iserv/remote-iserv.cabal.in
index 7ecf099eac..24c5c99c74 100644
--- a/utils/remote-iserv/remote-iserv.cabal.in
+++ b/utils/remote-iserv/remote-iserv.cabal.in
@@ -13,7 +13,7 @@ Synopsis: iserv allows GHC to delegate Template Haskell computations
 Description:
   This is a very simple remote runner for iserv, to be used together
   with iserv-proxy.  The foundamental idea is that this this wrapper
-  starts running libiserv on a given port to which iserv-proxy will
+  starts running the GHCi server on a given port to which iserv-proxy will
   then connect.
 Category: Development
 build-type: Simple
@@ -24,4 +24,4 @@ Executable remote-iserv
    Main-Is: Cli.hs
    Hs-Source-Dirs: src
    Build-Depends: base       >= 4   && < 5,
-                  libiserv   == @ProjectVersionMunged@
+                  ghci       == @ProjectVersionMunged@