X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fghci%2FInteractiveUI.hs;h=707b2785006872f7eba436d7950b881022d49c6a;hb=3355c9d53b220ccb110e5a3c81a1a8b2c9c41555;hp=c3c163aab172da51988ae324bcd657a7acf8ed61;hpb=f81c9189fccc07c33506de8480648f28f893d882;p=ghc-hetmet.git

diff --git a/ghc/compiler/ghci/InteractiveUI.hs b/ghc/compiler/ghci/InteractiveUI.hs
index c3c163a..125c899 100644
--- a/ghc/compiler/ghci/InteractiveUI.hs
+++ b/ghc/compiler/ghci/InteractiveUI.hs
@@ -1,210 +1,421 @@
+{-# OPTIONS -#include "Linker.h" #-}
 -----------------------------------------------------------------------------
--- $Id: InteractiveUI.hs,v 1.27 2001/01/18 10:51:53 simonmar Exp $
+-- $Id: InteractiveUI.hs,v 1.146 2003/02/19 15:54:07 simonpj Exp $
 --
 -- GHC Interactive User Interface
 --
 -- (c) The GHC Team 2000
 --
 -----------------------------------------------------------------------------
+module InteractiveUI ( 
+	interactiveUI,  -- :: CmState -> [FilePath] -> [LibrarySpec] -> IO ()
+	ghciWelcomeMsg
+   ) where
 
-module InteractiveUI (interactiveUI) where
-
+#include "../includes/config.h"
 #include "HsVersions.h"
 
 import CompManager
-import CmStaticInfo
+import HscTypes		( TyThing(..), HomeModInfo(hm_linkable), HomePackageTable,
+			  isObjectLinkable )
+import HsSyn		( TyClDecl(..), ConDecl(..), Sig(..) )
+import MkIface		( ifaceTyThing )
 import DriverFlags
 import DriverState
-import Linker
-import Module
-import Outputable
+import DriverUtil	( remove_spaces, handle )
+import Linker		( initLinker, showLinkerState, linkLibraries, 
+			  linkPackages )
 import Util
-import PprType	{- instance Outputable Type; do not delete -}
-import Panic	( GhcException(..) )
+import IdInfo		( GlobalIdDetails(..) )
+import Id		( isImplicitId, idName )
+import Class		( className )
+import TyCon		( tyConName, tyConClass_maybe, isPrimTyCon, DataConDetails(..) )
+import DataCon		( dataConName )
+import FieldLabel	( fieldLabelTyCon )
+import SrcLoc		( isGoodSrcLoc )
+import Module		( showModMsg, lookupModuleEnv )
+import Name		( Name, isHomePackageName, nameSrcLoc, nameOccName,
+			  NamedThing(..) )
+import OccName		( isSymOcc )
+import BasicTypes	( defaultFixity, SuccessFlag(..) )
+import Packages
+import Outputable
+import CmdLineOpts	( DynFlag(..), DynFlags(..), getDynFlags, saveDynFlags,
+			  restoreDynFlags, dopt_unset )
+import Panic 		hiding ( showException )
+import Config
+
+#ifndef mingw32_TARGET_OS
+import System.Posix
+#endif
 
-import Exception
-#ifndef NO_READLINE
-import Readline
+#if HAVE_READLINE_HEADERS && HAVE_READLINE_LIBS
+import Control.Concurrent	( yield )	-- Used in readline loop
+import System.Console.Readline as Readline
 #endif
-import IOExts
+
+--import SystemExts
+
+import Control.Exception as Exception
+import Data.Dynamic
+import Control.Concurrent
 
 import Numeric
-import List
-import System
-import CPUTime
-import Directory
-import IO
-import Char
-import Monad ( when )
+import Data.List
+import System.Cmd
+import System.CPUTime
+import System.Environment
+import System.Directory
+import System.IO as IO
+import Data.Char
+import Control.Monad as Monad
+
+import GHC.Exts		( unsafeCoerce# )
+
+import Data.IORef	( IORef, newIORef, readIORef, writeIORef )
 
+import GHC.Posix	( setNonBlockingFD )
 
 -----------------------------------------------------------------------------
 
 ghciWelcomeMsg = "\ 
-\ _____  __   __  ____         _________________________________________________\n\ 
-\(|	 ||   || (|  |)        GHC Interactive, version 5.00   	                \n\ 
-\||  __  ||___|| ||     ()     For Haskell 98.                    		\n\ 
-\||   |) ||---|| ||     ||     http://www.haskell.org/ghc         		\n\ 
-\||   || ||   || ||     (|     Bug reports to: glasgow-haskell-bugs@haskell.org \n\ 
-\(|___|| ||   || (|__|) \\\\______________________________________________________\n"
-
-commands :: [(String, String -> GHCi Bool)]
-commands = [
-  ("add",	keepGoing addModule),
+\   ___         ___ _\n\ 
+\  / _ \\ /\\  /\\/ __(_)\n\ 
+\ / /_\\// /_/ / /  | |      GHC Interactive, version " ++ cProjectVersion ++ ", for Haskell 98.\n\ 
+\/ /_\\\\/ __  / /___| |      http://www.haskell.org/ghc/\n\ 
+\\\____/\\/ /_/\\____/|_|      Type :? for help.\n"
+
+GLOBAL_VAR(commands, builtin_commands, [(String, String -> GHCi Bool)])
+
+builtin_commands :: [(String, String -> GHCi Bool)]
+builtin_commands = [
+  ("add",	keepGoingPaths addModule),
+  ("browse",    keepGoing browseCmd),
   ("cd",    	keepGoing changeDirectory),
+  ("def",	keepGoing defineMacro),
   ("help",	keepGoing help),
   ("?",		keepGoing help),
-  ("load",	keepGoing loadModule),
+  ("info",      keepGoing info),
+  ("load",	keepGoingPaths loadModule),
   ("module",	keepGoing setContext),
   ("reload",	keepGoing reloadModule),
-  ("set",	keepGoing setOptions),
+  ("set",	keepGoing setCmd),
+  ("show",	keepGoing showCmd),
   ("type",	keepGoing typeOfExpr),
   ("unset",	keepGoing unsetOptions),
+  ("undef",     keepGoing undefineMacro),
   ("quit",	quit)
   ]
 
 keepGoing :: (String -> GHCi ()) -> (String -> GHCi Bool)
 keepGoing a str = a str >> return False
 
+keepGoingPaths :: ([FilePath] -> GHCi ()) -> (String -> GHCi Bool)
+keepGoingPaths a str = a (toArgs str) >> return False
+
 shortHelpText = "use :? for help.\n"
 
+-- NOTE: spaces at the end of each line to workaround CPP/string gap bug.
 helpText = "\ 
 \ Commands available from the prompt:\n\ 
-\\  
-\   <expr>		evaluate <expr>\n\ 
-\   :add <filename>     add a module to the current set\n\ 
-\   :cd <dir>		change directory to <dir>\n\ 
-\   :help, :?		display this list of commands\n\ 
-\   :load <filename>    load a module (and it dependents)\n\ 
-\   :module <mod>	set the context for expression evaluation to <mod>\n\ 
-\   :reload		reload the current module set\n\ 
-\   :set <option> ...	set options\n\ 
-\   :unset <option> ...	unset options\n\ 
-\   :type <expr>	show the type of <expr>\n\ 
-\   :quit		exit GHCi\n\ 
-\   :!<command>		run the shell command <command>\n\ 
-\\ 
+\\n\ 
+\   <stmt>		       evaluate/run <stmt>\n\ 
+\   :add <filename> ...        add module(s) to the current target set\n\ 
+\   :browse [*]<module>	       display the names defined by <module>\n\ 
+\   :cd <dir>		       change directory to <dir>\n\ 
+\   :def <cmd> <expr>          define a command :<cmd>\n\ 
+\   :help, :?		       display this list of commands\n\ 
+\   :info [<name> ...]         display information about the given names\n\ 
+\   :load <filename> ...       load module(s) and their dependents\n\ 
+\   :module [+/-] [*]<mod> ... set the context for expression evaluation\n\ 
+\   :reload		       reload the current module set\n\ 
+\\n\ 
+\   :set <option> ...	       set options\n\ 
+\   :set args <arg> ...	       set the arguments returned by System.getArgs\n\ 
+\   :set prog <progname>       set the value returned by System.getProgName\n\ 
+\\n\ 
+\   :show modules	       show the currently loaded modules\n\ 
+\   :show bindings	       show the current bindings made at the prompt\n\ 
+\\n\ 
+\   :type <expr>	       show the type of <expr>\n\ 
+\   :undef <cmd> 	       undefine user-defined command :<cmd>\n\ 
+\   :unset <option> ...	       unset options\n\ 
+\   :quit		       exit GHCi\n\ 
+\   :!<command>		       run the shell command <command>\n\ 
+\\n\ 
 \ Options for `:set' and `:unset':\n\ 
-\\ 
+\\n\ 
+\    +r			revert top-level expressions after each evaluation\n\ 
 \    +s                 print timing/memory stats after each evaluation\n\ 
 \    +t			print type after evaluation\n\ 
 \    -<flags>		most GHC command line flags can also be set here\n\ 
 \                         (eg. -v2, -fglasgow-exts, etc.)\n\ 
 \"
 
-interactiveUI :: CmState -> Maybe FilePath -> IO ()
-interactiveUI cmstate mod = do
-   hPutStrLn stdout ghciWelcomeMsg
+interactiveUI :: CmState -> [FilePath] -> [FilePath] -> IO ()
+interactiveUI cmstate paths cmdline_objs = do
    hFlush stdout
    hSetBuffering stdout NoBuffering
 
-   -- link in the available packages
-   pkgs <- getPackageInfo
-   linkPackages (reverse pkgs)
+   dflags <- getDynFlags
+
+   initLinker
+
+	-- link packages requested explicitly on the command-line
+   expl <- readIORef v_ExplicitPackages
+   linkPackages dflags expl
+
+	-- link libraries from the command-line
+   linkLibraries dflags cmdline_objs
 
-   (cmstate', ok, mods) <-
-   	case mod of
-	     Nothing  -> return (cmstate, True, [])
-	     Just m -> cmLoadModule cmstate m
+	-- Initialise buffering for the *interpreted* I/O system
+   cmstate <- initInterpBuffering cmstate dflags
 
-#ifndef NO_READLINE
+	-- We don't want the cmd line to buffer any input that might be
+	-- intended for the program, so unbuffer stdin.
+   hSetBuffering stdin NoBuffering
+
+	-- initial context is just the Prelude
+   cmstate <- cmSetContext cmstate dflags [] ["Prelude"]
+
+#if HAVE_READLINE_HEADERS && HAVE_READLINE_LIBS
    Readline.initialize
 #endif
-   let this_mod = case mods of 
-			[] -> defaultCurrentModule
-			m:ms -> m
-
-   (unGHCi uiLoop) GHCiState{ modules = mods,
-			      current_module = this_mod,
-	  	              target = mod,
-			      cmstate = cmstate',
-			      options = [ShowTiming],
-                              last_expr = Nothing}
+
+   startGHCi (runGHCi paths dflags) 
+	GHCiState{ progname = "<interactive>",
+		   args = [],
+		   targets = paths,
+		   cmstate = cmstate,
+		   options = [] }
+
+#if HAVE_READLINE_HEADERS && HAVE_READLINE_LIBS
+   Readline.resetTerminal Nothing
+#endif
+
    return ()
 
-uiLoop :: GHCi ()
-uiLoop = do
-  st <- getGHCiState
-#ifndef NO_READLINE
-  l <- io (readline (moduleNameUserString (current_module st) ++ "> "))
+runGHCi :: [FilePath] -> DynFlags -> GHCi ()
+runGHCi paths dflags = do
+  read_dot_files <- io (readIORef v_Read_DotGHCi)
+
+  when (read_dot_files) $ do
+    -- Read in ./.ghci.
+    let file = "./.ghci"
+    exists <- io (doesFileExist file)
+    when exists $ do
+       dir_ok  <- io (checkPerms ".")
+       file_ok <- io (checkPerms file)
+       when (dir_ok && file_ok) $ do
+  	  either_hdl <- io (IO.try (openFile "./.ghci" ReadMode))
+  	  case either_hdl of
+  	     Left e    -> return ()
+  	     Right hdl -> fileLoop hdl False
+    
+  when (read_dot_files) $ do
+    -- Read in $HOME/.ghci
+    either_dir <- io (IO.try (getEnv "HOME"))
+    case either_dir of
+       Left e -> return ()
+       Right dir -> do
+  	  cwd <- io (getCurrentDirectory)
+  	  when (dir /= cwd) $ do
+  	     let file = dir ++ "/.ghci"
+  	     ok <- io (checkPerms file)
+  	     when ok $ do
+  	       either_hdl <- io (IO.try (openFile file ReadMode))
+  	       case either_hdl of
+  		  Left e    -> return ()
+  		  Right hdl -> fileLoop hdl False
+
+  -- perform a :load for files given on the GHCi command line
+  when (not (null paths)) $
+     ghciHandle showException $
+	loadModule paths
+
+  -- enter the interactive loop
+#if defined(mingw32_TARGET_OS)
+   -- always show prompt, since hIsTerminalDevice returns True for Consoles
+   -- only, which we may or may not be running under (cf. Emacs sub-shells.)
+  interactiveLoop True
+#else
+  is_tty <- io (hIsTerminalDevice stdin)
+  interactiveLoop is_tty
+#endif
+
+  -- and finally, exit
+  io $ do when (verbosity dflags > 0) $ putStrLn "Leaving GHCi."
+
+
+interactiveLoop is_tty = do
+  -- ignore ^C exceptions caught here
+  ghciHandleDyn (\e -> case e of 
+			Interrupted -> ghciUnblock (interactiveLoop is_tty)
+			_other      -> return ()) $ do
+
+  -- read commands from stdin
+#if HAVE_READLINE_HEADERS && HAVE_READLINE_LIBS
+  if (is_tty) 
+	then readlineLoop
+	else fileLoop stdin False  -- turn off prompt for non-TTY input
 #else
-  l_ok <- io (hGetLine stdin)
-  let l = Just l_ok
+  fileLoop stdin is_tty
 #endif
-  case l of
-    Nothing -> exitGHCi
-    Just "" -> uiLoop
-    Just l  -> do
-#ifndef NO_READLINE
-          io (addHistory l)
+
+
+-- NOTE: We only read .ghci files if they are owned by the current user,
+-- and aren't world writable.  Otherwise, we could be accidentally 
+-- running code planted by a malicious third party.
+
+-- Furthermore, We only read ./.ghci if . is owned by the current user
+-- and isn't writable by anyone else.  I think this is sufficient: we
+-- don't need to check .. and ../.. etc. because "."  always refers to
+-- the same directory while a process is running.
+
+checkPerms :: String -> IO Bool
+checkPerms name =
+#ifdef mingw32_TARGET_OS
+  return True
+#else
+  DriverUtil.handle (\_ -> return False) $ do
+     st <- getFileStatus name
+     me <- getRealUserID
+     if fileOwner st /= me then do
+   	putStrLn $ "WARNING: " ++ name ++ " is owned by someone else, IGNORING!"
+   	return False
+      else do
+   	let mode =  fileMode st
+   	if (groupWriteMode == (mode `intersectFileModes` groupWriteMode))
+   	   || (otherWriteMode == (mode `intersectFileModes` otherWriteMode)) 
+   	   then do
+   	       putStrLn $ "*** WARNING: " ++ name ++ 
+   			  " is writable by someone else, IGNORING!"
+   	       return False
+   	  else return True
 #endif
-  	  quit <- runCommand l
-          if quit then exitGHCi else uiLoop
 
-exitGHCi = io $ do putStrLn "Leaving GHCi." 
+fileLoop :: Handle -> Bool -> GHCi ()
+fileLoop hdl prompt = do
+   cmstate <- getCmState
+   (mod,imports) <- io (cmGetContext cmstate)
+   when prompt (io (putStr (mkPrompt mod imports)))
+   l <- io (IO.try (hGetLine hdl))
+   case l of
+	Left e | isEOFError e -> return ()
+	       | otherwise    -> io (ioError e)
+	Right l -> 
+	  case remove_spaces l of
+	    "" -> fileLoop hdl prompt
+	    l  -> do quit <- runCommand l
+          	     if quit then return () else fileLoop hdl prompt
+
+stringLoop :: [String] -> GHCi ()
+stringLoop [] = return ()
+stringLoop (s:ss) = do
+   case remove_spaces s of
+	"" -> stringLoop ss
+	l  -> do quit <- runCommand l
+                 if quit then return () else stringLoop ss
+
+mkPrompt toplevs exports
+   = concat (intersperse " " (map ('*':) toplevs ++ exports)) ++ "> "
+
+#if HAVE_READLINE_HEADERS && HAVE_READLINE_LIBS
+readlineLoop :: GHCi ()
+readlineLoop = do
+   cmstate <- getCmState
+   (mod,imports) <- io (cmGetContext cmstate)
+   io yield
+   l <- io (readline (mkPrompt mod imports)
+	  	`finally` setNonBlockingFD 0)
+		-- readline sometimes puts stdin into blocking mode,
+		-- so we need to put it back for the IO library
+   case l of
+	Nothing -> return ()
+	Just l  ->
+	  case remove_spaces l of
+	    "" -> readlineLoop
+	    l  -> do
+        	  io (addHistory l)
+  	  	  quit <- runCommand l
+          	  if quit then return () else readlineLoop
+#endif
 
--- Top level exception handler, just prints out the exception 
--- and carries on.
 runCommand :: String -> GHCi Bool
-runCommand c = 
-  ghciHandle ( 
-     \other_exception 
-        -> io (putStrLn (show other_exception)) >> return False
-  ) $
-  ghciHandleDyn
-    (\dyn -> case dyn of
-		PhaseFailed phase code ->
-			io ( putStrLn ("Phase " ++ phase ++ " failed (code "
-				        ++ show code ++ ")"))
-		Interrupted -> io (putStrLn "Interrupted.")
-		_ -> io (putStrLn (show (dyn :: GhcException)))
-             >> return False
-    ) $
-   doCommand c
+runCommand c = ghciHandle handler (doCommand c)
+
+-- This is the exception handler for exceptions generated by the
+-- user's code; it normally just prints out the exception.  The
+-- handler must be recursive, in case showing the exception causes
+-- more exceptions to be raised.
+--
+-- Bugfix: if the user closed stdout or stderr, the flushing will fail,
+-- raising another exception.  We therefore don't put the recursive
+-- handler arond the flushing operation, so if stderr is closed
+-- GHCi will just die gracefully rather than going into an infinite loop.
+handler :: Exception -> GHCi Bool
+handler exception = do
+  flushInterpBuffers
+  io installSignalHandlers
+  ghciHandle handler (showException exception >> return False)
+
+showException (DynException dyn) =
+  case fromDynamic dyn of
+    Nothing               -> io (putStrLn ("*** Exception: (unknown)"))
+    Just Interrupted      -> io (putStrLn "Interrupted.")
+    Just (CmdLineError s) -> io (putStrLn s)	 -- omit the location for CmdLineError
+    Just ph@PhaseFailed{} -> io (putStrLn (showGhcException ph "")) -- ditto
+    Just other_ghc_ex     -> io (print other_ghc_ex)
+
+showException other_exception
+  = io (putStrLn ("*** Exception: " ++ show other_exception))
 
 doCommand (':' : command) = specialCommand command
-doCommand expr
-   = do expr_expanded <- expandExpr expr
-        -- io (putStrLn ( "Before: " ++ expr ++ "\nAfter:  " ++ expr_expanded))
-        expr_ok <- timeIt (do ok <- evalExpr expr_expanded
-                              when ok (evalExpr "PrelIO.putChar \'\\n\'" >> return ())
-                              return ok)
-        when expr_ok (rememberExpr expr_expanded)
+doCommand stmt
+   = do timeIt (do nms <- runStmt stmt; finishEvalExpr nms)
         return False
 
--- Returned Bool indicates whether or not the expr was successfully
--- parsed, renamed and typechecked.
-evalExpr :: String -> GHCi Bool
-evalExpr expr
- | null (filter (not.isSpace) expr)
- = return False
+runStmt :: String -> GHCi [Name]
+runStmt stmt
+ | null (filter (not.isSpace) stmt) = return []
  | otherwise
  = do st <- getGHCiState
-      dflags <- io (getDynFlags)
-      (new_cmstate, maybe_stuff) <- 
-      	 io (cmGetExpr (cmstate st) dflags (current_module st) expr True)
+      dflags <- io getDynFlags
+      let dflags' = dopt_unset dflags Opt_WarnUnusedBinds
+      (new_cmstate, result) <- 
+	io $ withProgName (progname st) $ withArgs (args st) $
+	cmRunStmt (cmstate st) dflags' stmt
       setGHCiState st{cmstate = new_cmstate}
-      case maybe_stuff of
-      	 Nothing -> return False
-      	 Just (hv, unqual, ty)
-	   -> do io (cmRunExpr hv)
-		 b <- isOptionSet ShowType
-		 io (when b (printForUser stdout unqual (text "::" <+> ppr ty)))
-                 return True
-	
-{-
-  let (mod,'.':str) = break (=='.') expr
-  case cmLookupSymbol (mkOrig varName (mkModuleName mod) (_PK_ str)) (cmstate st) of
-	Nothing -> io (putStrLn "nothing.")
-	Just e  -> io (
-  return ()
--}
+      case result of
+	CmRunFailed      -> return []
+	CmRunException e -> showException e >> return []
+	CmRunOk names    -> return names
+
+-- possibly print the type and revert CAFs after evaluating an expression
+finishEvalExpr names
+ = do b <- isOptionSet ShowType
+      cmstate <- getCmState
+      when b (mapM_ (showTypeOfName cmstate) names)
+
+      flushInterpBuffers
+      io installSignalHandlers
+      b <- isOptionSet RevertCAFs
+      io (when b revertCAFs)
+      return True
+
+showTypeOfName :: CmState -> Name -> GHCi ()
+showTypeOfName cmstate n
+   = do maybe_str <- io (cmTypeOfName cmstate n)
+	case maybe_str of
+	  Nothing  -> return ()
+	  Just str -> io (putStrLn (showSDoc (ppr n) ++ " :: " ++ str))
 
 specialCommand :: String -> GHCi Bool
-specialCommand ('!':str) = shellEscape (dropWhile isSpace str) 
+specialCommand ('!':str) = shellEscape (dropWhile isSpace str)
 specialCommand str = do
   let (cmd,rest) = break isSpace str
-  case [ (s,f) | (s,f) <- commands, prefixMatch cmd s ] of
+  cmds <- io (readIORef commands)
+  case [ (s,f) | (s,f) <- cmds, prefixMatch cmd s ] of
      []      -> io (hPutStr stdout ("unknown command `:" ++ cmd ++ "'\n" 
 		                    ++ shortHelpText) >> return False)
      [(_,f)] -> f (dropWhile isSpace rest)
@@ -213,7 +424,47 @@ specialCommand str = do
 	         	     	       foldr1 (\a b -> a ++ ',':b) (map fst cs)
 					 ++ ")") >> return False)
 
-noArgs c = io (hPutStrLn stdout ("command `:" ++ c ++ "' takes no arguments"))
+noArgs c = throwDyn (CmdLineError ("command `" ++ c ++ "' takes no arguments"))
+
+
+-----------------------------------------------------------------------------
+-- To flush buffers for the *interpreted* computation we need
+-- to refer to *its* stdout/stderr handles
+
+GLOBAL_VAR(flush_interp,       error "no flush_interp", IO ())
+GLOBAL_VAR(turn_off_buffering, error "no flush_stdout", IO ())
+
+no_buf_cmd = "IO.hSetBuffering IO.stdout IO.NoBuffering" ++
+	     " Prelude.>> IO.hSetBuffering IO.stderr IO.NoBuffering"
+flush_cmd  = "IO.hFlush IO.stdout Prelude.>> IO.hFlush IO.stderr"
+
+initInterpBuffering :: CmState -> DynFlags -> IO CmState
+initInterpBuffering cmstate dflags
+ = do (cmstate, maybe_hval) <- cmCompileExpr cmstate dflags no_buf_cmd
+	
+      case maybe_hval of
+	Just hval -> writeIORef turn_off_buffering (unsafeCoerce# hval :: IO ())
+	other	  -> panic "interactiveUI:setBuffering"
+	
+      (cmstate, maybe_hval) <- cmCompileExpr cmstate dflags flush_cmd
+      case maybe_hval of
+	Just hval -> writeIORef flush_interp (unsafeCoerce# hval :: IO ())
+	_         -> panic "interactiveUI:flush"
+
+      turnOffBuffering	-- Turn it off right now
+
+      return cmstate
+
+
+flushInterpBuffers :: GHCi ()
+flushInterpBuffers
+ = io $ do Monad.join (readIORef flush_interp)
+           return ()
+
+turnOffBuffering :: IO ()
+turnOffBuffering
+ = do Monad.join (readIORef turn_off_buffering)
+      return ()
 
 -----------------------------------------------------------------------------
 -- Commands
@@ -221,77 +472,200 @@ noArgs c = io (hPutStrLn stdout ("command `:" ++ c ++ "' takes no arguments"))
 help :: String -> GHCi ()
 help _ = io (putStr helpText)
 
-addModule :: String -> GHCi ()
-addModule _ = throwDyn (OtherError ":add not implemented")
+info :: String -> GHCi ()
+info "" = throwDyn (CmdLineError "syntax: `:i <thing-you-want-info-about>'")
+info s = do
+  let names = words s
+  init_cms <- getCmState
+  dflags <- io getDynFlags
+  let 
+    infoThings cms [] = return cms
+    infoThings cms (name:names) = do
+      (cms, stuff) <- io (cmInfoThing cms dflags name)
+      io (putStrLn (showSDocForUser unqual (
+	    vcat (intersperse (text "") (map showThing stuff))))
+         )
+      infoThings cms names
+
+    unqual = cmGetPrintUnqual init_cms
+
+    showThing (ty_thing, fixity) 
+	= vcat [ text "-- " <> showTyThing ty_thing, 
+		 showFixity fixity (getName ty_thing),
+	         ppr (ifaceTyThing ty_thing) ]
+
+    showFixity fix name
+	| fix == defaultFixity = empty
+	| otherwise            = ppr fix <+> 
+				 (if isSymOcc (nameOccName name)
+					then ppr name
+					else char '`' <> ppr name <> char '`')
+
+    showTyThing (AClass cl)
+       = hcat [ppr cl, text " is a class", showSrcLoc (className cl)]
+    showTyThing (ADataCon dc)
+       = hcat [ppr dc, text " is a data constructor", showSrcLoc (dataConName dc)]
+    showTyThing (ATyCon ty)
+       | isPrimTyCon ty
+       = hcat [ppr ty, text " is a primitive type constructor"]
+       | otherwise
+       = hcat [ppr ty, text " is a type constructor", showSrcLoc (tyConName ty)]
+    showTyThing (AnId   id)
+       = hcat [ppr id, text " is a ", idDescr id, showSrcLoc (idName id)]
+
+    idDescr id
+       = case globalIdDetails id of
+	    RecordSelId lbl -> text "record selector for type" <+> ppr (fieldLabelTyCon lbl)
+	    ClassOpId cls   -> text "method in class" <+> ppr cls
+       	    otherwise       -> text "variable"
+
+	-- also print out the source location for home things
+    showSrcLoc name
+	| isHomePackageName name && isGoodSrcLoc loc
+	= hsep [ text ", defined at", ppr loc ]
+	| otherwise
+	= empty
+	where loc = nameSrcLoc name
+
+  cms <- infoThings init_cms names
+  setCmState cms
+  return ()
 
-setContext :: String -> GHCi ()
-setContext ""
-  = throwDyn (OtherError "syntax: `:m <module>'")
-setContext m | not (isUpper (head m)) || not (all isAlphaNum (tail m))
-  = throwDyn (OtherError ("strange looking module name: `" ++ m ++ "'"))
-setContext m
-  = do st <- getGHCiState
-       setGHCiState st{current_module = mkModuleName m}
+addModule :: [FilePath] -> GHCi ()
+addModule files = do
+  state <- getGHCiState
+  dflags <- io (getDynFlags)
+  io (revertCAFs)			-- always revert CAFs on load/add.
+  let new_targets = files ++ targets state 
+  graph <- io (cmDepAnal (cmstate state) dflags new_targets)
+  (cmstate1, ok, mods) <- io (cmLoadModules (cmstate state) dflags graph)
+  setGHCiState state{ cmstate = cmstate1, targets = new_targets }
+  setContextAfterLoad mods
+  modulesLoadedMsg ok mods dflags
 
 changeDirectory :: String -> GHCi ()
+changeDirectory ('~':d) = do
+   tilde <- io (getEnv "HOME")	-- will fail if HOME not defined
+   io (setCurrentDirectory (tilde ++ '/':d))
 changeDirectory d = io (setCurrentDirectory d)
 
-loadModule :: String -> GHCi ()
-loadModule path = timeIt (loadModule' path)
-
-loadModule' path = do
+defineMacro :: String -> GHCi ()
+defineMacro s = do
+  let (macro_name, definition) = break isSpace s
+  cmds <- io (readIORef commands)
+  if (null macro_name) 
+	then throwDyn (CmdLineError "invalid macro name") 
+	else do
+  if (macro_name `elem` map fst cmds) 
+	then throwDyn (CmdLineError 
+		("command `" ++ macro_name ++ "' is already defined"))
+	else do
+
+  -- give the expression a type signature, so we can be sure we're getting
+  -- something of the right type.
+  let new_expr = '(' : definition ++ ") :: String -> IO String"
+
+  -- compile the expression
+  cms <- getCmState
+  dflags <- io getDynFlags
+  (new_cmstate, maybe_hv) <- io (cmCompileExpr cms dflags new_expr)
+  setCmState new_cmstate
+  case maybe_hv of
+     Nothing -> return ()
+     Just hv -> io (writeIORef commands --
+		    ((macro_name, keepGoing (runMacro hv)) : cmds))
+
+runMacro :: HValue{-String -> IO String-} -> String -> GHCi ()
+runMacro fun s = do
+  str <- io ((unsafeCoerce# fun :: String -> IO String) s)
+  stringLoop (lines str)
+
+undefineMacro :: String -> GHCi ()
+undefineMacro macro_name = do
+  cmds <- io (readIORef commands)
+  if (macro_name `elem` map fst builtin_commands) 
+	then throwDyn (CmdLineError
+		("command `" ++ macro_name ++ "' cannot be undefined"))
+	else do
+  if (macro_name `notElem` map fst cmds) 
+	then throwDyn (CmdLineError 
+		("command `" ++ macro_name ++ "' not defined"))
+	else do
+  io (writeIORef commands (filter ((/= macro_name) . fst) cmds))
+
+
+loadModule :: [FilePath] -> GHCi ()
+loadModule fs = timeIt (loadModule' fs)
+
+loadModule' :: [FilePath] -> GHCi ()
+loadModule' files = do
   state <- getGHCiState
-  cmstate1 <- io (cmUnload (cmstate state))
-  (cmstate2, ok, mods) <- io (cmLoadModule cmstate1 path)
-
-  let new_state = state{
-  			cmstate = cmstate2,
-			modules = mods,
-			current_module = case mods of 
-					   [] -> defaultCurrentModule
-					   xs -> head xs,
-			target = Just path
-		   }
-  setGHCiState new_state
-
-  let mod_commas 
-	| null mods = text "none."
-	| otherwise = hsep (
-	    punctuate comma (map (text.moduleNameUserString) mods)) <> text "."
-  case ok of
-    False -> 
-       io (putStrLn (showSDoc (text "Failed, modules loaded: " <> mod_commas)))
-    True  -> 
-       io (putStrLn (showSDoc (text "Ok, modules loaded: " <> mod_commas)))
+  dflags <- io getDynFlags
+
+  -- do the dependency anal first, so that if it fails we don't throw
+  -- away the current set of modules.
+  graph <- io (cmDepAnal (cmstate state) dflags files)
+
+  -- Dependency anal ok, now unload everything
+  cmstate1 <- io (cmUnload (cmstate state) dflags)
+  setGHCiState state{ cmstate = cmstate1, targets = [] }
+
+  io (revertCAFs)  -- always revert CAFs on load.
+  (cmstate2, ok, mods) <- io (cmLoadModules cmstate1 dflags graph)
+  setGHCiState state{ cmstate = cmstate2, targets = files }
+
+  setContextAfterLoad mods
+  modulesLoadedMsg ok mods dflags
+
 
 reloadModule :: String -> GHCi ()
 reloadModule "" = do
   state <- getGHCiState
-  case target state of
-   Nothing -> io (putStr "no current target\n")
-   Just path
-      -> do (new_cmstate, ok, mods) <- io (cmLoadModule (cmstate state) path)
-            setGHCiState 
-               state{cmstate=new_cmstate,
-                     modules = mods,
-                     current_module = case mods of 
-                                         [] -> defaultCurrentModule
-                                         xs -> head xs
-                    }
-
+  dflags <- io getDynFlags
+  case targets state of
+   [] -> io (putStr "no current target\n")
+   paths -> do
+	-- do the dependency anal first, so that if it fails we don't throw
+	-- away the current set of modules.
+	graph <- io (cmDepAnal (cmstate state) dflags paths)
+
+	io (revertCAFs)		-- always revert CAFs on reload.
+	(cmstate1, ok, mods) 
+		<- io (cmLoadModules (cmstate state) dflags graph)
+        setGHCiState state{ cmstate=cmstate1 }
+	setContextAfterLoad mods
+	modulesLoadedMsg ok mods dflags
 
 reloadModule _ = noArgs ":reload"
 
+setContextAfterLoad [] = setContext prel
+setContextAfterLoad (m:_) = do
+  cmstate <- getCmState
+  b <- io (cmModuleIsInterpreted cmstate m)
+  if b then setContext ('*':m) else setContext m
+
+modulesLoadedMsg ok mods dflags =
+  when (verbosity dflags > 0) $ do
+   let mod_commas 
+	| null mods = text "none."
+	| otherwise = hsep (
+	    punctuate comma (map text mods)) <> text "."
+   case ok of
+    Failed ->
+       io (putStrLn (showSDoc (text "Failed, modules loaded: " <> mod_commas)))
+    Succeeded  ->
+       io (putStrLn (showSDoc (text "Ok, modules loaded: " <> mod_commas)))
+
+
 typeOfExpr :: String -> GHCi ()
 typeOfExpr str 
-  = do st <- getGHCiState
-       dflags <- io (getDynFlags)
-       (new_cmstate, maybe_ty) <- io (cmGetExpr (cmstate st) dflags 
-				(current_module st) str False)
-       setGHCiState st{cmstate = new_cmstate}
-       case maybe_ty of
-	 Nothing -> return ()
-	 Just (_, unqual, ty) -> io (printForUser stdout unqual (ppr ty)) 
+  = do cms <- getCmState
+       dflags <- io getDynFlags
+       (new_cmstate, maybe_tystr) <- io (cmTypeOfExpr cms dflags str)
+       setCmState new_cmstate
+       case maybe_tystr of
+	  Nothing    -> return ()
+	  Just tystr -> io (putStrLn tystr)
 
 quit :: String -> GHCi Bool
 quit _ = return True
@@ -299,6 +673,132 @@ quit _ = return True
 shellEscape :: String -> GHCi Bool
 shellEscape str = io (system str >> return False)
 
+-----------------------------------------------------------------------------
+-- Browing a module's contents
+
+browseCmd :: String -> GHCi ()
+browseCmd m = 
+  case words m of
+    ['*':m] | looksLikeModuleName m -> browseModule m False
+    [m]     | looksLikeModuleName m -> browseModule m True
+    _ -> throwDyn (CmdLineError "syntax:  :browse <module>")
+
+browseModule m exports_only = do
+  cms <- getCmState
+  dflags <- io getDynFlags
+
+  is_interpreted <- io (cmModuleIsInterpreted cms m)
+  when (not is_interpreted && not exports_only) $
+	throwDyn (CmdLineError ("module `" ++ m ++ "' is not interpreted"))
+
+  -- temporarily set the context to the module we're interested in,
+  -- just so we can get an appropriate PrintUnqualified
+  (as,bs) <- io (cmGetContext cms)
+  cms1 <- io (if exports_only then cmSetContext cms dflags [] [prel,m]
+			      else cmSetContext cms dflags [m] [])
+  cms2 <- io (cmSetContext cms1 dflags as bs)
+
+  (cms3, things) <- io (cmBrowseModule cms2 dflags m exports_only)
+
+  setCmState cms3
+
+  let unqual = cmGetPrintUnqual cms1 -- NOTE: cms1 with the new context
+
+      things' = filter wantToSee things
+
+      wantToSee (AnId id)    = not (isImplicitId id)
+      wantToSee (ADataCon _) = False	-- They'll come via their TyCon
+      wantToSee _ 	     = True
+
+      thing_names = map getName things
+
+      thingDecl thing@(AnId id)  = ifaceTyThing thing
+
+      thingDecl thing@(AClass c) =
+        let rn_decl = ifaceTyThing thing in
+	case rn_decl of
+	  ClassDecl { tcdSigs = cons } -> 
+		rn_decl{ tcdSigs = filter methodIsVisible cons }
+	  other -> other
+        where
+           methodIsVisible (ClassOpSig n _ _ _) = n `elem` thing_names
+
+      thingDecl thing@(ATyCon t) =
+        let rn_decl = ifaceTyThing thing in
+	case rn_decl of
+	  TyData { tcdCons = DataCons cons } -> 
+		rn_decl{ tcdCons = DataCons (filter conIsVisible cons) }
+	  other -> other
+        where
+	  conIsVisible (ConDecl n _ _ _ _) = n `elem` thing_names
+
+  io (putStrLn (showSDocForUser unqual (
+   	 vcat (map (ppr . thingDecl) things')))
+   )
+
+  where
+
+-----------------------------------------------------------------------------
+-- Setting the module context
+
+setContext str
+  | all sensible mods = fn mods
+  | otherwise = throwDyn (CmdLineError "syntax:  :module [+/-] [*]M1 ... [*]Mn")
+  where
+    (fn, mods) = case str of 
+			'+':stuff -> (addToContext,      words stuff)
+			'-':stuff -> (removeFromContext, words stuff)
+			stuff     -> (newContext,        words stuff) 
+
+    sensible ('*':m) = looksLikeModuleName m
+    sensible m       = looksLikeModuleName m
+
+newContext mods = do
+  cms <- getCmState
+  dflags <- io getDynFlags
+  (as,bs) <- separate cms mods [] []
+  let bs' = if null as && prel `notElem` bs then prel:bs else bs
+  cms' <- io (cmSetContext cms dflags as bs')
+  setCmState cms'
+
+separate cmstate []           as bs = return (as,bs)
+separate cmstate (('*':m):ms) as bs = do
+   b <- io (cmModuleIsInterpreted cmstate m)
+   if b then separate cmstate ms (m:as) bs
+   	else throwDyn (CmdLineError ("module `" ++ m ++ "' is not interpreted"))
+separate cmstate (m:ms)       as bs = separate cmstate ms as (m:bs)
+
+prel = "Prelude"
+
+
+addToContext mods = do
+  cms <- getCmState
+  dflags <- io getDynFlags
+  (as,bs) <- io (cmGetContext cms)
+
+  (as',bs') <- separate cms mods [] []
+
+  let as_to_add = as' \\ (as ++ bs)
+      bs_to_add = bs' \\ (as ++ bs)
+
+  cms' <- io (cmSetContext cms dflags 
+			(as ++ as_to_add) (bs ++ bs_to_add))
+  setCmState cms'
+
+
+removeFromContext mods = do
+  cms <- getCmState
+  dflags <- io getDynFlags
+  (as,bs) <- io (cmGetContext cms)
+
+  (as_to_remove,bs_to_remove) <- separate cms mods [] []
+
+  let as' = as \\ (as_to_remove ++ bs_to_remove)
+      bs' = bs \\ (as_to_remove ++ bs_to_remove)
+
+  cms' <- io (cmSetContext cms dflags as' bs')
+  setCmState cms'
+
 ----------------------------------------------------------------------------
 -- Code for `:set'
 
@@ -309,8 +809,8 @@ shellEscape str = io (system str >> return False)
 -- This is pretty fragile: most options won't work as expected.  ToDo:
 -- figure out which ones & disallow them.
 
-setOptions :: String -> GHCi ()
-setOptions ""
+setCmd :: String -> GHCi ()
+setCmd ""
   = do st <- getGHCiState
        let opts = options st
        io $ putStrLn (showSDoc (
@@ -319,30 +819,54 @@ setOptions ""
    		   then text "none."
    		   else hsep (map (\o -> char '+' <> text (optToStr o)) opts)
    	   ))
-setOptions str
-  = do -- first, deal with the GHCi opts (+s, +t, etc.)
-       let opts = words str
-	   (minus_opts, rest1) = partition isMinus opts
-	   (plus_opts, rest2)  = partition isPlus rest1
+setCmd str
+  = case words str of
+	("args":args) -> setArgs args
+	("prog":prog) -> setProg prog
+	wds -> setOptions wds
 
-       if (not (null rest2)) 
-	  then io (putStrLn ("unknown option: `" ++ head rest2 ++ "'"))
-	  else do
+setArgs args = do
+  st <- getGHCiState
+  setGHCiState st{ args = args }
 
-       mapM setOpt plus_opts
-
-       -- now, the GHC flags
-       io (do leftovers <- processArgs static_flags minus_opts []
-	      dyn_flags <- readIORef v_InitDynFlags
-	      writeIORef v_DynFlags dyn_flags
-	      leftovers <- processArgs dynamic_flags leftovers []
-	      dyn_flags <- readIORef v_DynFlags
-	      writeIORef v_InitDynFlags dyn_flags
-              if (not (null leftovers))
-		 then throwDyn (OtherError ("unrecognised flags: " ++ 
+setProg [prog] = do
+  st <- getGHCiState
+  setGHCiState st{ progname = prog }
+setProg _ = do
+  io (hPutStrLn stderr "syntax: :set prog <progname>")
+
+setOptions wds =
+   do -- first, deal with the GHCi opts (+s, +t, etc.)
+      let (plus_opts, minus_opts)  = partition isPlus wds
+      mapM_ setOpt plus_opts
+
+      -- now, the GHC flags
+      pkgs_before <- io (readIORef v_ExplicitPackages)
+      leftovers   <- io (processArgs static_flags minus_opts [])
+      pkgs_after  <- io (readIORef v_ExplicitPackages)
+
+      -- update things if the users wants more packages
+      let new_packages = pkgs_after \\ pkgs_before
+      when (not (null new_packages)) $
+	 newPackages new_packages
+
+      -- don't forget about the extra command-line flags from the 
+      -- extra_ghc_opts fields in the new packages
+      new_package_details <- io (getPackageDetails new_packages)
+      let pkg_extra_opts = concatMap extra_ghc_opts new_package_details
+      pkg_extra_dyn <- io (processArgs static_flags pkg_extra_opts [])
+
+      -- then, dynamic flags
+      io $ do 
+	restoreDynFlags
+        leftovers <- processArgs dynamic_flags (leftovers ++ pkg_extra_dyn) []
+	saveDynFlags
+
+        if (not (null leftovers))
+		then throwDyn (CmdLineError ("unrecognised flags: " ++ 
 						unwords leftovers))
-		 else return ()
-         )
+		else return ()
+
 
 unsetOptions :: String -> GHCi ()
 unsetOptions str
@@ -355,11 +879,11 @@ unsetOptions str
 	  then io (putStrLn ("unknown option: `" ++ head rest2 ++ "'"))
 	  else do
 
-       mapM unsetOpt plus_opts
+       mapM_ unsetOpt plus_opts
  
        -- can't do GHC flags for now
        if (not (null minus_opts))
-	  then throwDyn (OtherError "can't unset GHC command-line flags")
+	  then throwDyn (CmdLineError "can't unset GHC command-line flags")
 	  else return ()
 
 isMinus ('-':s) = True
@@ -381,49 +905,57 @@ unsetOpt ('+':str)
 strToGHCiOpt :: String -> (Maybe GHCiOption)
 strToGHCiOpt "s" = Just ShowTiming
 strToGHCiOpt "t" = Just ShowType
+strToGHCiOpt "r" = Just RevertCAFs
 strToGHCiOpt _   = Nothing
 
 optToStr :: GHCiOption -> String
 optToStr ShowTiming = "s"
 optToStr ShowType   = "t"
-
-
------------------------------------------------------------------------------
--- Code to do last-expression-entered stuff.  (a.k.a the $$ facility)
-
--- Take a string and replace $$s in it with the last expr, if any.
-expandExpr :: String -> GHCi String
-expandExpr str
-   = do mle <- getLastExpr
-        return (outside mle str)
-     where
-        outside mle ('$':'$':cs)
-           = case mle of
-                Just le -> " (" ++ le ++ ") " ++ outside mle cs
-                Nothing -> outside mle cs
-
-        outside mle []           = []
-        outside mle ('"':str)    = '"' : inside2 mle str   -- "
-        outside mle ('\'':str)   = '\'' : inside1 mle str   -- '
-        outside mle (c:cs)       = c : outside mle cs
-
-        inside2 mle ('"':cs)  = '"' : outside mle cs   -- "
-        inside2 mle (c:cs)    = c : inside2 mle cs
-        inside2 mle []        = []
-
-        inside1 mle ('\'':cs) = '\'': outside mle cs
-        inside1 mle (c:cs)    = c : inside1 mle cs
-        inside1 mle []        = []
-
-
-rememberExpr :: String -> GHCi ()
-rememberExpr str
-   = do let cleaned = (clean . reverse . clean . reverse) str
-        let forget_me_not | null cleaned = Nothing
-                          | otherwise    = Just cleaned
-        setLastExpr forget_me_not
-     where
-        clean = dropWhile isSpace
+optToStr RevertCAFs = "r"
+
+newPackages new_pkgs = do	-- The new packages are already in v_Packages
+  state    <- getGHCiState
+  dflags   <- io getDynFlags
+  cmstate1 <- io (cmUnload (cmstate state) dflags)
+  setGHCiState state{ cmstate = cmstate1, targets = [] }
+  io (linkPackages dflags new_pkgs)
+  setContextAfterLoad []
+
+-- ---------------------------------------------------------------------------
+-- code for `:show'
+
+showCmd str =
+  case words str of
+	["modules" ] -> showModules
+	["bindings"] -> showBindings
+	["linker"]   -> io showLinkerState
+	_ -> throwDyn (CmdLineError "syntax:  :show [modules|bindings]")
+
+showModules = do
+  cms <- getCmState
+  let (mg, hpt) = cmGetModInfo cms
+  mapM_ (showModule hpt) mg
+
+
+showModule :: HomePackageTable -> ModSummary -> GHCi ()
+showModule hpt mod_summary
+  = case lookupModuleEnv hpt mod of
+	Nothing	      -> panic "missing linkable"
+	Just mod_info -> io (putStrLn (showModMsg obj_linkable mod locn))
+		      where
+			 obj_linkable = isObjectLinkable (hm_linkable mod_info)
+  where
+    mod = ms_mod mod_summary
+    locn = ms_location mod_summary
+
+showBindings = do
+  cms <- getCmState
+  let
+	unqual = cmGetPrintUnqual cms
+	showBinding b = putStrLn (showSDocForUser unqual (ppr (ifaceTyThing b)))
+
+  io (mapM_ showBinding (cmGetBindings cms))
+  return ()
 
 
 -----------------------------------------------------------------------------
@@ -431,26 +963,38 @@ rememberExpr str
 
 data GHCiState = GHCiState
      { 
-	modules	       :: [ModuleName],
-	current_module :: ModuleName,
-	target         :: Maybe FilePath,
+	progname       :: String,
+	args	       :: [String],
+	targets        :: [FilePath],
 	cmstate        :: CmState,
-	options        :: [GHCiOption],
-        last_expr      :: Maybe String
+	options        :: [GHCiOption]
      }
 
-data GHCiOption = ShowTiming | ShowType deriving Eq
+data GHCiOption 
+	= ShowTiming		-- show time/allocs after evaluation
+	| ShowType		-- show the type of expressions
+	| RevertCAFs		-- revert CAFs after every evaluation
+	deriving Eq
 
-defaultCurrentModule = mkModuleName "Prelude"
+newtype GHCi a = GHCi { unGHCi :: IORef GHCiState -> IO a }
 
-newtype GHCi a = GHCi { unGHCi :: GHCiState -> IO (GHCiState, a) }
+startGHCi :: GHCi a -> GHCiState -> IO a
+startGHCi g state = do ref <- newIORef state; unGHCi g ref
 
 instance Monad GHCi where
-  (GHCi m) >>= k  =  GHCi $ \s -> m s >>= \(s,a) -> unGHCi (k a) s
-  return a  = GHCi $ \s -> return (s,a)
+  (GHCi m) >>= k  =  GHCi $ \s -> m s >>= \a -> unGHCi (k a) s
+  return a  = GHCi $ \s -> return a
+
+ghciHandleDyn :: Typeable t => (t -> GHCi a) -> GHCi a -> GHCi a
+ghciHandleDyn h (GHCi m) = GHCi $ \s -> 
+   Exception.catchDyn (m s) (\e -> unGHCi (h e) s)
 
-getGHCiState   = GHCi $ \s -> return (s,s)
-setGHCiState s = GHCi $ \_ -> return (s,())
+getGHCiState   = GHCi $ \r -> readIORef r
+setGHCiState s = GHCi $ \r -> writeIORef r s
+
+-- for convenience...
+getCmState = getGHCiState >>= return . cmstate
+setCmState cms = do s <- getGHCiState; setGHCiState s{cmstate=cms}
 
 isOptionSet :: GHCiOption -> GHCi Bool
 isOptionSet opt
@@ -467,48 +1011,23 @@ unsetOption opt
  = do st <- getGHCiState
       setGHCiState (st{ options = filter (/= opt) (options st) })
 
-getLastExpr :: GHCi (Maybe String)
-getLastExpr
- = do st <- getGHCiState ; return (last_expr st)
+io :: IO a -> GHCi a
+io m = GHCi { unGHCi = \s -> m >>= return }
 
-setLastExpr :: Maybe String -> GHCi ()
-setLastExpr last_expr
- = do st <- getGHCiState ; setGHCiState (st{last_expr = last_expr})
+-----------------------------------------------------------------------------
+-- recursive exception handlers
 
-io m = GHCi $ \s -> m >>= \a -> return (s,a)
+-- Don't forget to unblock async exceptions in the handler, or if we're
+-- in an exception loop (eg. let a = error a in a) the ^C exception
+-- may never be delivered.  Thanks to Marcin for pointing out the bug.
 
+ghciHandle :: (Exception -> GHCi a) -> GHCi a -> GHCi a
 ghciHandle h (GHCi m) = GHCi $ \s -> 
-   Exception.catch (m s) (\e -> unGHCi (h e) s)
-ghciHandleDyn h (GHCi m) = GHCi $ \s -> 
-   Exception.catchDyn (m s) (\e -> unGHCi (h e) s)
+   Exception.catch (m s) 
+	(\e -> unGHCi (ghciUnblock (h e)) s)
 
------------------------------------------------------------------------------
--- package loader
-
-linkPackages :: [Package] -> IO ()
-linkPackages pkgs = mapM_ linkPackage pkgs
-
-linkPackage :: Package -> IO ()
--- ignore rts and gmp for now (ToDo; better?)
-linkPackage pkg | name pkg `elem` ["rts", "gmp"] = return ()
-linkPackage pkg = do
-  putStr ("Loading package " ++ name pkg ++ " ... ")
-  let dirs = library_dirs pkg
-  let objs = map (++".o") (hs_libraries pkg ++ extra_libraries pkg)
-  mapM (linkOneObj dirs) objs
-  putStr "resolving ... "
-  resolveObjs
-  putStrLn "done."
-
-linkOneObj dirs obj = do
-  filename <- findFile dirs obj
-  loadObj filename
-
-findFile [] obj = throwDyn (OtherError ("can't find " ++ obj))
-findFile (d:ds) obj = do
-  let path = d ++ '/':obj
-  b <- doesFileExist path
-  if b then return path else findFile ds obj
+ghciUnblock :: GHCi a -> GHCi a
+ghciUnblock (GHCi a) = GHCi $ \s -> Exception.unblock (a s)
 
 -----------------------------------------------------------------------------
 -- timing & statistics
@@ -526,7 +1045,7 @@ timeIt action
 		  io $ printTimes (allocs2 - allocs1) (time2 - time1)
 		  return a
 
-foreign import "getAllocations" getAllocations :: IO Int
+foreign import ccall "getAllocations" getAllocations :: IO Int
 
 printTimes :: Int -> Integer -> IO ()
 printTimes allocs psecs
@@ -535,3 +1054,16 @@ printTimes allocs psecs
 	putStrLn (showSDoc (
 		 parens (text (secs_str "") <+> text "secs" <> comma <+> 
 			 int allocs <+> text "bytes")))
+
+-----------------------------------------------------------------------------
+-- reverting CAFs
+	
+revertCAFs :: IO ()
+revertCAFs = do
+  rts_revertCAFs
+  turnOffBuffering
+	-- Have to turn off buffering again, because we just 
+	-- reverted stdout, stderr & stdin to their defaults.
+
+foreign import ccall "revertCAFs" rts_revertCAFs  :: IO ()  
+	-- Make it "safe", just in case