X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fghci%2FInteractiveUI.hs;h=d2a96fcd2e4a99afd9168a2a3ec8bb53e67fbc2c;hb=315a1f6c671b9800909752c702bda347198dd60a;hp=a03b2fe3ddeaf15ba8fef907295408789c1e9700;hpb=d9d1dc64baab3284103676fb14b4128e47a1da4f;p=ghc-hetmet.git

diff --git a/ghc/compiler/ghci/InteractiveUI.hs b/ghc/compiler/ghci/InteractiveUI.hs
index a03b2fe..c4b5f97 100644
--- a/ghc/compiler/ghci/InteractiveUI.hs
+++ b/ghc/compiler/ghci/InteractiveUI.hs
@@ -1,203 +1,410 @@
+{-# OPTIONS -#include "Linker.h" #-}
 -----------------------------------------------------------------------------
--- $Id: InteractiveUI.hs,v 1.37 2001/02/09 15:33:51 simonmar Exp $
 --
 -- GHC Interactive User Interface
 --
--- (c) The GHC Team 2000
+-- (c) The GHC Team 2005
 --
 -----------------------------------------------------------------------------
-
-module InteractiveUI (interactiveUI) where
+module InteractiveUI ( 
+	interactiveUI,
+	ghciWelcomeMsg
+   ) where
 
 #include "HsVersions.h"
 
-import CompManager
-import CmStaticInfo
-import ByteCodeLink
-import DriverFlags
-import DriverState
-import DriverUtil
-import Type
-import Linker
-import Finder
-import Module
+-- The GHC interface
+import qualified GHC
+import GHC		( Session, verbosity, dopt, DynFlag(..), Target(..),
+			  TargetId(..), DynFlags(..),
+			  pprModule, Type, Module, SuccessFlag(..),
+			  TyThing(..), Name, LoadHowMuch(..), Phase,
+			  GhcException(..), showGhcException,
+			  CheckedModule(..), SrcLoc )
+import Packages		( PackageState(..) )
+import PackageConfig	( InstalledPackageInfo(..) )
+import UniqFM		( eltsUFM )
+import PprTyThing
 import Outputable
-import Util
-import PprType		{- instance Outputable Type; do not delete -}
-import Panic		( GhcException(..) )
-
-import Exception
-import Dynamic
-#ifndef NO_READLINE
-import Readline
+
+-- for createtags (should these come via GHC?)
+import Module		( moduleString )
+import Name		( nameSrcLoc, nameModule, nameOccName )
+import OccName		( pprOccName )
+import SrcLoc		( isGoodSrcLoc, srcLocFile, srcLocLine, srcLocCol )
+
+-- Other random utilities
+import Digraph		( flattenSCCs )
+import BasicTypes	( failed, successIf )
+import Panic 		( panic, installSignalHandlers )
+import Config
+import StaticFlags	( opt_IgnoreDotGhci )
+import Linker		( showLinkerState )
+import Util		( removeSpaces, handle, global, toArgs,
+			  looksLikeModuleName, prefixMatch, sortLe )
+
+#ifndef mingw32_HOST_OS
+import System.Posix
+#if __GLASGOW_HASKELL__ > 504
+	hiding (getEnv)
+#endif
+#else
+import GHC.ConsoleHandler ( flushConsole )
 #endif
-import IOExts
 
-import Numeric
-import List
-import System
-import CPUTime
-import Directory
-import IO
-import Char
-import Monad ( when )
+#ifdef USE_READLINE
+import Control.Concurrent	( yield )	-- Used in readline loop
+import System.Console.Readline as Readline
+#endif
 
+--import SystemExts
+
+import Control.Exception as Exception
+import Data.Dynamic
+-- import Control.Concurrent
+
+import Numeric
+import Data.List
+import Data.Int		( Int64 )
+import Data.Maybe	( isJust, fromMaybe, catMaybes )
+import System.Cmd
+import System.CPUTime
+import System.Environment
+import System.Exit	( exitWith, ExitCode(..) )
+import System.Directory
+import System.IO
+import System.IO.Error as IO
+import Data.Char
+import Control.Monad as Monad
+import Foreign.StablePtr	( newStablePtr )
+import Text.Printf
+
+import GHC.Exts		( unsafeCoerce# )
+import GHC.IOBase	( IOErrorType(InvalidArgument) )
+
+import Data.IORef	( IORef, newIORef, readIORef, writeIORef )
+
+import System.Posix.Internals ( setNonBlockingFD )
 
 -----------------------------------------------------------------------------
 
-ghciWelcomeMsg = "\ 
-\   ___         ___ _ 							     \n\ 
-\  / _ \\ /\\  /\\/ __(_)      GHC Interactive, version 5.00, For Haskell 98.   \n\ 
-\ / /_\\// /_/ / /  | |      http://www.haskell.org/ghc                       \n\ 
-\/ /_\\\\/ __  / /___| |      Bug reports to: glasgow-haskell-bugs@haskell.org \n\ 
-\\\____/\\/ /_/\\____/|_|      Type :? for help.\n"
-
-commands :: [(String, String -> GHCi Bool)]
-commands = [
-  ("add",	keepGoing addModule),
-  ("cd",    	keepGoing changeDirectory),
-  ("help",	keepGoing help),
-  ("?",		keepGoing help),
-  ("load",	keepGoing loadModule),
-  ("module",	keepGoing setContext),
-  ("reload",	keepGoing reloadModule),
-  ("set",	keepGoing setOptions),
-  ("type",	keepGoing typeOfExpr),
-  ("unset",	keepGoing unsetOptions),
-  ("quit",	quit)
+ghciWelcomeMsg =
+ "   ___         ___ _\n"++
+ "  / _ \\ /\\  /\\/ __(_)\n"++
+ " / /_\\// /_/ / /  | |      GHC Interactive, version " ++ cProjectVersion ++ ", for Haskell 98.\n"++
+ "/ /_\\\\/ __  / /___| |      http://www.haskell.org/ghc/\n"++
+ "\\____/\\/ /_/\\____/|_|      Type :? for help.\n"
+
+type Command = (String, String -> GHCi Bool, String -> IO [String])
+cmdName (n,_,_) = n
+
+GLOBAL_VAR(commands, builtin_commands, [Command])
+
+builtin_commands :: [Command]
+builtin_commands = [
+  ("add",	keepGoingPaths addModule,	completeFilename),
+  ("browse",    keepGoing browseCmd,		completeModule),
+  ("cd",    	keepGoing changeDirectory, 	completeFilename),
+  ("def",	keepGoing defineMacro,		completeIdentifier),
+  ("help",	keepGoing help,			completeNone),
+  ("?",		keepGoing help,			completeNone),
+  ("info",      keepGoing info,			completeIdentifier),
+  ("load",	keepGoingPaths loadModule_,	completeHomeModuleOrFile),
+  ("module",	keepGoing setContext,		completeModule),
+  ("main",	keepGoing runMain,		completeIdentifier),
+  ("reload",	keepGoing reloadModule,		completeNone),
+  ("check",	keepGoing checkModule,		completeHomeModule),
+  ("set",	keepGoing setCmd,		completeNone), -- ToDo
+  ("show",	keepGoing showCmd,		completeNone),
+  ("etags",	keepGoing createETagsFileCmd,	completeFilename),
+  ("ctags",	keepGoing createCTagsFileCmd, 	completeFilename),
+  ("type",	keepGoing typeOfExpr,		completeIdentifier),
+  ("kind",	keepGoing kindOfType,		completeIdentifier),
+  ("unset",	keepGoing unsetOptions,		completeNone), -- ToDo
+  ("undef",     keepGoing undefineMacro,	completeNone), -- ToDo
+  ("quit",	quit,				completeNone)
   ]
 
 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"
 
-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\ 
-\\ 
-\ Options for `:set' and `:unset':\n\ 
-\\ 
-\    +s                 print timing/memory stats after each evaluation\n\ 
-\    +t			print type after evaluation\n\ 
-\    +r			revert top-level expressions after each 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
+-- NOTE: spaces at the end of each line to workaround CPP/string gap bug.
+helpText =
+ " Commands available from the prompt:\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" ++
+ "   :main [<arguments> ...]     run the main function with the given arguments\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" ++
+ "   :ctags [<file>]             create tags file for Vi (default: \"tags\")\n" ++
+ "   :etags [<file>]           	 create tags file for Emacs (defauilt: \"TAGS\")\n" ++
+ "   :type <expr>                show the type of <expr>\n" ++
+ "   :kind <type>                show the kind of <type>\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 :: Session -> [(FilePath, Maybe Phase)] -> Maybe String -> IO ()
+interactiveUI session srcs maybe_expr = do
+
+   -- HACK! If we happen to get into an infinite loop (eg the user
+   -- types 'let x=x in x' at the prompt), then the thread will block
+   -- on a blackhole, and become unreachable during GC.  The GC will
+   -- detect that it is unreachable and send it the NonTermination
+   -- exception.  However, since the thread is unreachable, everything
+   -- it refers to might be finalized, including the standard Handles.
+   -- This sounds like a bug, but we don't have a good solution right
+   -- now.
+   newStablePtr stdin
+   newStablePtr stdout
+   newStablePtr stderr
+
    hFlush stdout
    hSetBuffering stdout NoBuffering
 
-   -- link in the available packages
-   pkgs <- getPackageInfo
-   linkPackages (reverse pkgs)
+	-- Initialise buffering for the *interpreted* I/O system
+   initInterpBuffering session
+
+	-- We don't want the cmd line to buffer any input that might be
+	-- intended for the program, so unbuffer stdin.
+   hSetBuffering stdin NoBuffering
 
-   (cmstate, ok, mods) <-
-   	case mod of
-	     Nothing  -> return (cmstate, True, [])
-	     Just m -> cmLoadModule cmstate m
+	-- initial context is just the Prelude
+   GHC.setContext session [] [prelude_mod]
 
-#ifndef NO_READLINE
+#ifdef USE_READLINE
    Readline.initialize
+   Readline.setAttemptedCompletionFunction (Just completeWord)
+   --Readline.parseAndBind "set show-all-if-ambiguous 1"
+
+   let symbols = "!#$%&*+/<=>?@\\^|-~"
+       specials = "(),;[]`{}"
+       spaces = " \t\n"
+       word_break_chars = spaces ++ specials ++ symbols
+
+   Readline.setBasicWordBreakCharacters word_break_chars
+   Readline.setCompleterWordBreakCharacters word_break_chars
 #endif
 
-   prel <- moduleNameToModule defaultCurrentModuleName
-   writeIORef defaultCurrentModule prel
+   startGHCi (runGHCi srcs maybe_expr)
+	GHCiState{ progname = "<interactive>",
+		   args = [],
+		   session = session,
+		   options = [] }
 
-   dflags <- getDynFlags
+#ifdef USE_READLINE
+   Readline.resetTerminal Nothing
+#endif
 
-   (cmstate, maybe_stuff) <- cmGetExpr cmstate dflags False prel 
-		  		"PrelHandle.hFlush PrelHandle.stdout"
-   case maybe_stuff of
-	Nothing -> return ()
-	Just (hv,_,_) -> writeIORef flush_stdout hv
-   
-   (cmstate, maybe_stuff) <- cmGetExpr cmstate dflags False prel 
-		  		"PrelHandle.hFlush PrelHandle.stdout"
-   case maybe_stuff of
-	Nothing -> return ()
-	Just (hv,_,_) -> writeIORef flush_stderr hv
-   
-   let this_mod = case mods of 
-	  	      []   -> prel
-  	  	      m:ms -> m
-
-   (unGHCi runGHCi) GHCiState{ modules = mods,
-			      current_module = this_mod,
-	  	              target = mod,
-			      cmstate = cmstate,
-			      options = [ShowTiming],
-                              last_expr = Nothing}
    return ()
 
+runGHCi :: [(FilePath, Maybe Phase)] -> Maybe String -> GHCi ()
+runGHCi paths maybe_expr = do
+  let read_dot_files = not opt_IgnoreDotGhci
+
+  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 in -e mode, if the load fails then we want to stop
+  -- immediately rather than going on to evaluate the expression.
+  when (not (null paths)) $ do
+     ok <- ghciHandle (\e -> do showException e; return Failed) $ 
+		loadModule paths
+     when (isJust maybe_expr && failed ok) $
+	io (exitWith (ExitFailure 1))
+
+  -- if verbosity is greater than 0, or we are connected to a
+  -- terminal, display the prompt in the interactive loop.
+  is_tty <- io (hIsTerminalDevice stdin)
+  dflags <- getDynFlags
+  let show_prompt = verbosity dflags > 0 || is_tty
+
+  case maybe_expr of
+	Nothing -> 
+#if defined(mingw32_HOST_OS)
+          do
+            -- The win32 Console API mutates the first character of 
+            -- type-ahead when reading from it in a non-buffered manner. Work
+            -- around this by flushing the input buffer of type-ahead characters,
+            -- but only if stdin is available.
+            flushed <- io (IO.try (GHC.ConsoleHandler.flushConsole stdin))
+            case flushed of 
+   	     Left err | isDoesNotExistError err -> return ()
+   		      | otherwise -> io (ioError err)
+   	     Right () -> return ()
+#endif
+	    -- enter the interactive loop
+	    interactiveLoop is_tty show_prompt
+	Just expr -> do
+	    -- just evaluate the expression we were given
+	    runCommandEval expr
+	    return ()
+
+  -- and finally, exit
+  io $ do when (verbosity dflags > 0) $ putStrLn "Leaving GHCi."
+
+
+interactiveLoop is_tty show_prompt =
+  -- Ignore ^C exceptions caught here
+  ghciHandleDyn (\e -> case e of 
+			Interrupted -> do
+#if defined(mingw32_HOST_OS)
+				io (putStrLn "")
+#endif
+				interactiveLoop is_tty show_prompt
+			_other      -> return ()) $ 
 
-runGHCi :: GHCi ()
-runGHCi = do
-  -- read in ./.ghci
-  dot_ghci <- io (IO.try (openFile "./.ghci" ReadMode))
-  case dot_ghci of
-	Left e -> return ()
-	Right hdl -> fileLoop hdl False
-  
-  -- read in ~/.ghci
-  home <- io (IO.try (getEnv "HOME"))
-  case home of
-   Left e  -> return ()
-   Right dir -> do
-  	dot_ghci <- io (IO.try (openFile (dir ++ "/.ghci") ReadMode))
-	case dot_ghci of
-	   Left e -> return ()
-	   Right hdl -> fileLoop hdl False
+  ghciUnblock $ do -- unblock necessary if we recursed from the 
+		   -- exception handler above.
 
   -- read commands from stdin
-#ifndef NO_READLINE
-  readlineLoop
+#ifdef USE_READLINE
+  if (is_tty) 
+	then readlineLoop
+	else fileLoop stdin show_prompt
 #else
-  fileLoop stdin True
+  fileLoop stdin show_prompt
 #endif
 
-  -- and finally, exit
-  io $ do putStrLn "Leaving GHCi." 
 
+-- 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_HOST_OS
+  return True
+#else
+  Util.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
 
 fileLoop :: Handle -> Bool -> GHCi ()
 fileLoop hdl prompt = do
-   st <- getGHCiState
-   when prompt (io (hPutStr hdl (moduleUserString (current_module st) ++ "> ")))
+   session <- getSession
+   (mod,imports) <- io (GHC.getContext session)
+   when prompt (io (putStr (mkPrompt mod imports)))
    l <- io (IO.try (hGetLine hdl))
    case l of
-	Left e | isEOFError e -> return ()
-	       | otherwise    -> throw e
+	Left e | isEOFError e		   -> return ()
+	       | InvalidArgument <- etype  -> return ()
+	       | otherwise		   -> io (ioError e)
+		where etype = ioeGetErrorType e
+		-- treat InvalidArgument in the same way as EOF:
+		-- this can happen if the user closed stdin, or
+		-- perhaps did getContents which closes stdin at
+		-- EOF.
 	Right l -> 
-	  case remove_spaces l of
+	  case removeSpaces l of
 	    "" -> fileLoop hdl prompt
 	    l  -> do quit <- runCommand l
           	     if quit then return () else fileLoop hdl prompt
 
-#ifndef NO_READLINE
+stringLoop :: [String] -> GHCi ()
+stringLoop [] = return ()
+stringLoop (s:ss) = do
+   case removeSpaces s of
+	"" -> stringLoop ss
+	l  -> do quit <- runCommand l
+                 if quit then return () else stringLoop ss
+
+mkPrompt toplevs exports
+  = showSDoc (hsep (map (\m -> char '*' <> pprModule m) toplevs)
+	     <+> hsep (map pprModule exports)
+	     <> text "> ")
+
+#ifdef USE_READLINE
 readlineLoop :: GHCi ()
 readlineLoop = do
-   st <- getGHCiState
-   l <- io (readline (moduleUserString (current_module st) ++ "> "))
+   session <- getSession
+   (mod,imports) <- io (GHC.getContext session)
+   io yield
+   saveSession -- for use by completion
+   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
+   splatSavedSession
    case l of
 	Nothing -> return ()
 	Just l  ->
-	  case remove_spaces l of
+	  case removeSpaces l of
 	    "" -> readlineLoop
 	    l  -> do
         	  io (addHistory l)
@@ -205,88 +412,155 @@ readlineLoop = do
           	  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 ( \exception -> 
-	(case exception of
-	   DynException dyn -> 
-	      case fromDynamic dyn of
-		Nothing -> io (putStrLn ("*** Exception: (unknown)"))
-		Just ghc_ex -> 
-		  case ghc_ex of
-		    PhaseFailed phase code ->
-			io ( putStrLn ("Phase " ++ phase ++ " failed (code "
-				        ++ show code ++ ")"))
-		    Interrupted -> io (putStrLn "Interrupted.")
-		    other -> io (putStrLn (show (ghc_ex :: GhcException)))
-
-	   other -> io (putStrLn ("*** Exception: " ++ show exception))
-
-	) >> return False
-     ) $
-
-   doCommand c
-
-doCommand (':' : command) = specialCommand command
-doCommand ('-':'-':_) = return False	-- comments, useful in scripts
-doCommand expr
-   = do expr_expanded <- expandExpr expr
-        -- io (putStrLn ( "Before: " ++ expr ++ "\nAfter:  " ++ expr_expanded))
-        expr_ok <- timeIt (do stuff <- evalExpr expr_expanded
-			      finishEvalExpr stuff)
-        when expr_ok (rememberExpr expr_expanded)
-        return False
+runCommand c = ghciHandle handler (doCommand c)
+  where 
+    doCommand (':' : command) = specialCommand command
+    doCommand stmt
+       = do timeIt (do nms <- runStmt stmt; finishEvalExpr nms)
+            return False
+
+-- This version is for the GHC command-line option -e.  The only difference
+-- from runCommand is that it catches the ExitException exception and
+-- exits, rather than printing out the exception.
+runCommandEval c = ghciHandle handleEval (doCommand c)
+  where 
+    handleEval (ExitException code) = io (exitWith code)
+    handleEval e                    = do showException e
+				         io (exitWith (ExitFailure 1))
+
+    doCommand (':' : command) = specialCommand command
+    doCommand stmt
+       = do nms <- runStmt stmt
+	    case nms of 
+		Nothing -> io (exitWith (ExitFailure 1))
+		  -- failure to run the command causes exit(1) for ghc -e.
+		_       -> finishEvalExpr nms
+
+-- 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))
+
+runStmt :: String -> GHCi (Maybe [Name])
+runStmt stmt
+ | null (filter (not.isSpace) stmt) = return (Just [])
+ | otherwise
+ = do st <- getGHCiState
+      session <- getSession
+      result <- io $ withProgName (progname st) $ withArgs (args st) $
+	     	     GHC.runStmt session stmt
+      case result of
+	GHC.RunFailed      -> return Nothing
+	GHC.RunException e -> throw e  -- this is caught by runCommand(Eval)
+	GHC.RunOk names    -> return (Just names)
 
 -- possibly print the type and revert CAFs after evaluating an expression
-finishEvalExpr Nothing = return False
-finishEvalExpr (Just (unqual,ty))
+finishEvalExpr mb_names
  = do b <- isOptionSet ShowType
-      io (when b (printForUser stdout unqual (text "::" <+> ppr ty)))
+      session <- getSession
+      case mb_names of
+	Nothing    -> return ()      
+	Just names -> when b (mapM_ (showTypeOfName session) names)
+
+      flushInterpBuffers
+      io installSignalHandlers
       b <- isOptionSet RevertCAFs
       io (when b revertCAFs)
       return True
 
--- Returned Bool indicates whether or not the expr was successfully
--- parsed, renamed and typechecked.
-evalExpr :: String -> GHCi (Maybe (PrintUnqualified,Type))
-evalExpr expr
- | null (filter (not.isSpace) expr)
- = return Nothing
- | otherwise
- = do st <- getGHCiState
-      dflags <- io (getDynFlags)
-      (new_cmstate, maybe_stuff) <- 
-      	 io (cmGetExpr (cmstate st) dflags True (current_module st) expr)
-      setGHCiState st{cmstate = new_cmstate}
-      case maybe_stuff of
-      	 Nothing -> return Nothing
-      	 Just (hv, unqual, ty) -> do io (cmRunExpr hv)
-		 		     flushEverything
-		 		     return (Just (unqual,ty))
-
-flushEverything :: GHCi ()
-flushEverything
-   = io $ do flush_so <- readIORef flush_stdout
-     	     cmRunExpr flush_so
-     	     flush_se <- readIORef flush_stdout
-     	     cmRunExpr flush_se
+showTypeOfName :: Session -> Name -> GHCi ()
+showTypeOfName session n
+   = do maybe_tything <- io (GHC.lookupName session n)
+	case maybe_tything of
+	  Nothing    -> return ()
+	  Just thing -> showTyThing thing
+
+showForUser :: SDoc -> GHCi String
+showForUser doc = do
+  session <- getSession
+  unqual <- io (GHC.getPrintUnqual session)
+  return $! showSDocForUser unqual doc
 
 specialCommand :: String -> GHCi Bool
 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
-     []      -> io (hPutStr stdout ("unknown command `:" ++ cmd ++ "'\n" 
+  maybe_cmd <- io (lookupCommand cmd)
+  case maybe_cmd of
+    Nothing -> io (hPutStr stdout ("unknown command ':" ++ cmd ++ "'\n" 
 		                    ++ shortHelpText) >> return False)
-     [(_,f)] -> f (dropWhile isSpace rest)
-     cs      -> io (hPutStrLn stdout ("prefix " ++ cmd ++ 
-			    	      " matches multiple commands (" ++ 
-	         	     	       foldr1 (\a b -> a ++ ',':b) (map fst cs)
-					 ++ ")") >> return False)
+    Just (_,f,_) -> f (dropWhile isSpace rest)
+
+lookupCommand :: String -> IO (Maybe Command)
+lookupCommand str = do
+  cmds <- readIORef commands
+  -- look for exact match first, then the first prefix match
+  case [ c | c <- cmds, str == cmdName c ] of
+     c:_ -> return (Just c)
+     [] -> case [ c | c@(s,_,_) <- cmds, prefixMatch str s ] of
+     		[] -> return Nothing
+     		c:_ -> return (Just c)
+
+-----------------------------------------------------------------------------
+-- 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 = "System.IO.hSetBuffering System.IO.stdout System.IO.NoBuffering" ++
+	     " Prelude.>> System.IO.hSetBuffering System.IO.stderr System.IO.NoBuffering"
+flush_cmd  = "System.IO.hFlush System.IO.stdout Prelude.>> System.IO.hFlush IO.stderr"
+
+initInterpBuffering :: Session -> IO ()
+initInterpBuffering session
+ = do maybe_hval <- GHC.compileExpr session no_buf_cmd
+	
+      case maybe_hval of
+	Just hval -> writeIORef turn_off_buffering (unsafeCoerce# hval :: IO ())
+	other	  -> panic "interactiveUI:setBuffering"
+	
+      maybe_hval <- GHC.compileExpr session flush_cmd
+      case maybe_hval of
+	Just hval -> writeIORef flush_interp (unsafeCoerce# hval :: IO ())
+	_         -> panic "interactiveUI:flush"
+
+      turnOffBuffering	-- Turn it off right now
+
+      return ()
+
 
-noArgs c = io (hPutStrLn stdout ("command `:" ++ c ++ "' takes no arguments"))
+flushInterpBuffers :: GHCi ()
+flushInterpBuffers
+ = io $ do Monad.join (readIORef flush_interp)
+           return ()
+
+turnOffBuffering :: IO ()
+turnOffBuffering
+ = do Monad.join (readIORef turn_off_buffering)
+      return ()
 
 -----------------------------------------------------------------------------
 -- Commands
@@ -294,93 +568,246 @@ 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")
-
-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 mn
-  = do m <- io (moduleNameToModule (mkModuleName mn))
-       st <- getGHCiState
-       if (isHomeModule m && m `notElem` modules st)
-	  then throwDyn (OtherError (showSDoc (quotes (ppr (moduleName m))
-				<+> text "is not currently loaded, use :load")))
-	  else setGHCiState st{current_module = m}
-
-moduleNameToModule :: ModuleName -> IO Module
-moduleNameToModule mn
- = do maybe_stuff <- findModule mn
-      case maybe_stuff of
-	 Nothing -> throwDyn (OtherError ("can't find module `"
-					    ++ moduleNameUserString mn ++ "'"))
-   	 Just (m,_) -> return m
+info :: String -> GHCi ()
+info "" = throwDyn (CmdLineError "syntax: ':i <thing-you-want-info-about>'")
+info s  = do { let names = words s
+	     ; session <- getSession
+	     ; dflags <- getDynFlags
+	     ; let exts = dopt Opt_GlasgowExts dflags
+	     ; mapM_ (infoThing exts session) names }
+  where
+    infoThing exts session str = io $ do
+	names <- GHC.parseName session str
+	let filtered = filterOutChildren names
+	mb_stuffs <- mapM (GHC.getInfo session) filtered
+	unqual <- GHC.getPrintUnqual session
+	putStrLn (showSDocForUser unqual $
+     		   vcat (intersperse (text "") $
+		   [ pprInfo exts stuff | Just stuff <-  mb_stuffs ]))
+
+  -- Filter out names whose parent is also there Good
+  -- example is '[]', which is both a type and data
+  -- constructor in the same type
+filterOutChildren :: [Name] -> [Name]
+filterOutChildren names = filter (not . parent_is_there) names
+ where parent_is_there n 
+	 | Just p <- GHC.nameParent_maybe n = p `elem` names
+	 | otherwise		           = False
+
+pprInfo exts (thing, fixity, insts)
+  =  pprTyThingInContextLoc exts thing 
+  $$ show_fixity fixity
+  $$ vcat (map GHC.pprInstance insts)
+  where
+    show_fixity fix 
+	| fix == GHC.defaultFixity = empty
+	| otherwise		   = ppr fix <+> ppr (GHC.getName thing)
+
+-----------------------------------------------------------------------------
+-- Commands
+
+runMain :: String -> GHCi ()
+runMain args = do
+  let ss = concat $ intersperse "," (map (\ s -> ('"':s)++"\"") (toArgs args))
+  runCommand $ '[': ss ++ "] `System.Environment.withArgs` main"
+  return ()
+
+addModule :: [FilePath] -> GHCi ()
+addModule files = do
+  io (revertCAFs)			-- always revert CAFs on load/add.
+  files <- mapM expandPath files
+  targets <- mapM (\m -> io (GHC.guessTarget m Nothing)) files
+  session <- getSession
+  io (mapM_ (GHC.addTarget session) targets)
+  ok <- io (GHC.load session LoadAllTargets)
+  afterLoad ok session
 
 changeDirectory :: String -> GHCi ()
-changeDirectory d = io (setCurrentDirectory d)
-
-loadModule :: String -> GHCi ()
-loadModule path = timeIt (loadModule' path)
-
-loadModule' path = do
-  state <- getGHCiState
-  cmstate1 <- io (cmUnload (cmstate state))
-  io (revertCAFs)			-- always revert CAFs on load.
-  (cmstate2, ok, mods) <- io (cmLoadModule cmstate1 path)
-
-  def_mod <- io (readIORef defaultCurrentModule)
-
-  let new_state = state{
-  			cmstate = cmstate2,
-			modules = mods,
-			current_module = case mods of 
-					   [] -> def_mod
-					   xs -> head xs,
-			target = Just path
-		   }
-  setGHCiState new_state
-
-  let mod_commas 
+changeDirectory dir = do
+  session <- getSession
+  graph <- io (GHC.getModuleGraph session)
+  when (not (null graph)) $
+	io $ putStr "Warning: changing directory causes all loaded modules to be unloaded,\nbecause the search path has changed.\n"
+  io (GHC.setTargets session [])
+  io (GHC.load session LoadAllTargets)
+  setContextAfterLoad session []
+  io (GHC.workingDirectoryChanged session)
+  dir <- expandPath dir
+  io (setCurrentDirectory dir)
+
+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 cmdName 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 <- getSession
+  maybe_hv <- io (GHC.compileExpr cms new_expr)
+  case maybe_hv of
+     Nothing -> return ()
+     Just hv -> io (writeIORef commands --
+		    (cmds ++ [(macro_name, keepGoing (runMacro hv), completeNone)]))
+
+runMacro :: GHC.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 cmdName builtin_commands) 
+	then throwDyn (CmdLineError
+		("command '" ++ macro_name ++ "' cannot be undefined"))
+	else do
+  if (macro_name `notElem` map cmdName cmds) 
+	then throwDyn (CmdLineError 
+		("command '" ++ macro_name ++ "' not defined"))
+	else do
+  io (writeIORef commands (filter ((/= macro_name) . cmdName) cmds))
+
+
+loadModule :: [(FilePath, Maybe Phase)] -> GHCi SuccessFlag
+loadModule fs = timeIt (loadModule' fs)
+
+loadModule_ :: [FilePath] -> GHCi ()
+loadModule_ fs = do loadModule (zip fs (repeat Nothing)); return ()
+
+loadModule' :: [(FilePath, Maybe Phase)] -> GHCi SuccessFlag
+loadModule' files = do
+  session <- getSession
+
+  -- unload first
+  io (GHC.setTargets session [])
+  io (GHC.load session LoadAllTargets)
+
+  -- expand tildes
+  let (filenames, phases) = unzip files
+  exp_filenames <- mapM expandPath filenames
+  let files' = zip exp_filenames phases
+  targets <- io (mapM (uncurry GHC.guessTarget) files')
+
+  -- NOTE: we used to do the dependency anal first, so that if it
+  -- fails we didn't throw away the current set of modules.  This would
+  -- require some re-working of the GHC interface, so we'll leave it
+  -- as a ToDo for now.
+
+  io (GHC.setTargets session targets)
+  ok <- io (GHC.load session LoadAllTargets)
+  afterLoad ok session
+  return ok
+
+checkModule :: String -> GHCi ()
+checkModule m = do
+  let modl = GHC.mkModule m
+  session <- getSession
+  result <- io (GHC.checkModule session modl)
+  case result of
+    Nothing -> io $ putStrLn "Nothing"
+    Just r  -> io $ putStrLn (showSDoc (
+	case checkedModuleInfo r of
+	   Just cm | Just scope <- GHC.modInfoTopLevelScope cm -> 
+		let
+		    (local,global) = partition ((== modl) . GHC.nameModule) scope
+		in
+			(text "global names: " <+> ppr global) $$
+		        (text "local  names: " <+> ppr local)
+	   _ -> empty))
+  afterLoad (successIf (isJust result)) session
+
+reloadModule :: String -> GHCi ()
+reloadModule "" = do
+  io (revertCAFs)		-- always revert CAFs on reload.
+  session <- getSession
+  ok <- io (GHC.load session LoadAllTargets)
+  afterLoad ok session
+reloadModule m = do
+  io (revertCAFs)		-- always revert CAFs on reload.
+  session <- getSession
+  ok <- io (GHC.load session (LoadUpTo (GHC.mkModule m)))
+  afterLoad ok session
+
+afterLoad ok session = do
+  io (revertCAFs)  -- always revert CAFs on load.
+  graph <- io (GHC.getModuleGraph session)
+  graph' <- filterM (io . GHC.isLoaded session . GHC.ms_mod) graph
+  setContextAfterLoad session graph'
+  modulesLoadedMsg ok (map GHC.ms_mod graph')
+
+setContextAfterLoad session [] = do
+  io (GHC.setContext session [] [prelude_mod])
+setContextAfterLoad session ms = do
+  -- load a target if one is available, otherwise load the topmost module.
+  targets <- io (GHC.getTargets session)
+  case [ m | Just m <- map (findTarget ms) targets ] of
+	[]    -> 
+	  let graph' = flattenSCCs (GHC.topSortModuleGraph True ms Nothing) in
+	  load_this (last graph')	  
+	(m:_) -> 
+	  load_this m
+ where
+   findTarget ms t
+    = case filter (`matches` t) ms of
+	[]    -> Nothing
+	(m:_) -> Just m
+
+   summary `matches` Target (TargetModule m) _
+	= GHC.ms_mod summary == m
+   summary `matches` Target (TargetFile f _) _ 
+	| Just f' <- GHC.ml_hs_file (GHC.ms_location summary)	= f == f'
+   summary `matches` target
+	= False
+
+   load_this summary | m <- GHC.ms_mod summary = do
+	b <- io (GHC.moduleIsInterpreted session m)
+	if b then io (GHC.setContext session [m] []) 
+       	     else io (GHC.setContext session []  [prelude_mod,m])
+
+
+modulesLoadedMsg :: SuccessFlag -> [Module] -> GHCi ()
+modulesLoadedMsg ok mods = do
+  dflags <- getDynFlags
+  when (verbosity dflags > 0) $ do
+   let mod_commas 
 	| null mods = text "none."
 	| otherwise = hsep (
-	    punctuate comma (map (text.moduleUserString) mods)) <> text "."
-  case ok of
-    False -> 
+	    punctuate comma (map pprModule mods)) <> text "."
+   case ok of
+    Failed ->
        io (putStrLn (showSDoc (text "Failed, modules loaded: " <> mod_commas)))
-    True  -> 
+    Succeeded  ->
        io (putStrLn (showSDoc (text "Ok, modules loaded: " <> mod_commas)))
 
-reloadModule :: String -> GHCi ()
-reloadModule "" = do
-  state <- getGHCiState
-  case target state of
-   Nothing -> io (putStr "no current target\n")
-   Just path
-      -> do io (revertCAFs)		-- always revert CAFs on reload.
-	    (new_cmstate, ok, mods) <- io (cmLoadModule (cmstate state) path)
-	    def_mod <- io (readIORef defaultCurrentModule)
-            setGHCiState 
-               state{cmstate=new_cmstate,
-                     modules = mods,
-                     current_module = case mods of 
-                                         [] -> def_mod
-                                         xs -> head xs
-                    }
-
-reloadModule _ = noArgs ":reload"
 
 typeOfExpr :: String -> GHCi ()
 typeOfExpr str 
-  = do st <- getGHCiState
-       dflags <- io (getDynFlags)
-       (new_cmstate, maybe_ty) <- io (cmGetExpr (cmstate st) dflags False
-					 (current_module st) str)
-       setGHCiState st{cmstate = new_cmstate}
+  = do cms <- getSession
+       maybe_ty <- io (GHC.exprType cms str)
+       case maybe_ty of
+	  Nothing -> return ()
+	  Just ty -> do ty' <- cleanType ty
+			tystr <- showForUser (ppr ty')
+		        io (putStrLn (str ++ " :: " ++ tystr))
+
+kindOfType :: String -> GHCi ()
+kindOfType str 
+  = do cms <- getSession
+       maybe_ty <- io (GHC.typeKind cms str)
        case maybe_ty of
-	 Nothing -> return ()
-	 Just (_, unqual, ty) -> io (printForUser stdout unqual (ppr ty)) 
+	  Nothing    -> return ()
+	  Just ty    -> do tystr <- showForUser (ppr ty)
+		           io (putStrLn (str ++ " :: " ++ tystr))
 
 quit :: String -> GHCi Bool
 quit _ = return True
@@ -388,6 +815,221 @@ quit _ = return True
 shellEscape :: String -> GHCi Bool
 shellEscape str = io (system str >> return False)
 
+-----------------------------------------------------------------------------
+-- create tags file for currently loaded modules.
+
+createETagsFileCmd, createCTagsFileCmd :: String -> GHCi ()
+
+createCTagsFileCmd ""   = ghciCreateTagsFile CTags "tags"
+createCTagsFileCmd file = ghciCreateTagsFile CTags file
+
+createETagsFileCmd ""    = ghciCreateTagsFile ETags "TAGS"
+createETagsFileCmd file  = ghciCreateTagsFile ETags file
+
+data TagsKind = ETags | CTags
+
+ghciCreateTagsFile :: TagsKind -> FilePath -> GHCi ()
+ghciCreateTagsFile kind file = do
+  session <- getSession
+  io $ createTagsFile session kind file
+
+-- ToDo: 
+-- 	- remove restriction that all modules must be interpreted
+--	  (problem: we don't know source locations for entities unless
+--	  we compiled the module.
+--
+--	- extract createTagsFile so it can be used from the command-line
+--	  (probably need to fix first problem before this is useful).
+--
+createTagsFile :: Session -> TagsKind -> FilePath -> IO ()
+createTagsFile session tagskind tagFile = do
+  graph <- GHC.getModuleGraph session
+  let ms = map GHC.ms_mod graph
+      tagModule m = do 
+        is_interpreted <- GHC.moduleIsInterpreted session m
+        -- should we just skip these?
+        when (not is_interpreted) $
+          throwDyn (CmdLineError ("module '" ++ moduleString m ++ "' is not interpreted"))
+
+        mbModInfo <- GHC.getModuleInfo session m
+        let unqual 
+	      | Just modinfo <- mbModInfo,
+		Just unqual <- GHC.modInfoPrintUnqualified modinfo = unqual
+	      | otherwise = GHC.alwaysQualify
+
+        case mbModInfo of 
+          Just modInfo -> return $! listTags unqual modInfo 
+          _            -> return []
+
+  mtags <- mapM tagModule ms
+  either_res <- collateAndWriteTags tagskind tagFile $ concat mtags
+  case either_res of
+    Left e  -> hPutStrLn stderr $ ioeGetErrorString e
+    Right _ -> return ()
+
+listTags :: PrintUnqualified -> GHC.ModuleInfo -> [TagInfo]
+listTags unqual modInfo =
+	   [ tagInfo unqual name loc 
+           | name <- GHC.modInfoExports modInfo
+           , let loc = nameSrcLoc name
+           , isGoodSrcLoc loc
+           ]
+
+type TagInfo = (String -- tag name
+               ,String -- file name
+               ,Int    -- line number
+               ,Int    -- column number
+               )
+
+-- get tag info, for later translation into Vim or Emacs style
+tagInfo :: PrintUnqualified -> Name -> SrcLoc -> TagInfo
+tagInfo unqual name loc
+    = ( showSDocForUser unqual $ pprOccName (nameOccName name)
+      , showSDocForUser unqual $ ftext (srcLocFile loc)
+      , srcLocLine loc
+      , srcLocCol loc
+      )
+
+collateAndWriteTags :: TagsKind -> FilePath -> [TagInfo] -> IO (Either IOError ())
+collateAndWriteTags CTags file tagInfos = do -- ctags style, Vim et al
+  let tags = unlines $ sortLe (<=) $ nub $ map showTag tagInfos
+  IO.try (writeFile file tags)
+collateAndWriteTags ETags file tagInfos = do -- etags style, Emacs/XEmacs
+  let byFile op (_,f1,_,_) (_,f2,_,_) = f1 `op` f2
+      groups = groupBy (byFile (==)) $ sortLe (byFile (<=)) tagInfos
+  tagGroups <- mapM tagFileGroup groups 
+  IO.try (writeFile file $ concat tagGroups)
+  where
+    tagFileGroup group@[] = throwDyn (CmdLineError "empty tag file group??")
+    tagFileGroup group@((_,fileName,_,_):_) = do
+      file <- readFile fileName -- need to get additional info from sources..
+      let byLine (_,_,l1,_) (_,_,l2,_) = l1 <= l2
+          sortedGroup = sortLe byLine group
+          tags = unlines $ perFile sortedGroup 1 0 $ lines file
+      return $ "\x0c\n" ++ fileName ++ "," ++ show (length tags) ++ "\n" ++ tags
+    perFile (tagInfo@(tag,file,lNo,colNo):tags) count pos (line:lines) | lNo>count =
+      perFile (tagInfo:tags) (count+1) (pos+length line) lines
+    perFile (tagInfo@(tag,file,lNo,colNo):tags) count pos lines@(line:_) | lNo==count =
+      showETag tagInfo line pos : perFile tags count pos lines
+    perFile tags count pos lines = []
+
+-- simple ctags format, for Vim et al
+showTag :: TagInfo -> String
+showTag (tag,file,lineNo,colNo)
+    =  tag ++ "\t" ++ file ++ "\t" ++ show lineNo
+
+-- etags format, for Emacs/XEmacs
+showETag :: TagInfo -> String -> Int -> String
+showETag (tag,file,lineNo,colNo) line charPos
+    =  take colNo line ++ tag
+    ++ "\x7f" ++ tag
+    ++ "\x01" ++ show lineNo
+    ++ "," ++ show charPos
+
+-----------------------------------------------------------------------------
+-- Browsing 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
+  s <- getSession
+
+  let modl = GHC.mkModule m
+  is_interpreted <- io (GHC.moduleIsInterpreted s modl)
+  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 (GHC.getContext s)
+  io (if exports_only then GHC.setContext s [] [prelude_mod,modl]
+		      else GHC.setContext s [modl] [])
+  unqual <- io (GHC.getPrintUnqual s)
+  io (GHC.setContext s as bs)
+
+  mb_mod_info <- io $ GHC.getModuleInfo s modl
+  case mb_mod_info of
+    Nothing -> throwDyn (CmdLineError ("unknown module: " ++ m))
+    Just mod_info -> do
+        let names
+	       | exports_only = GHC.modInfoExports mod_info
+	       | otherwise    = fromMaybe [] (GHC.modInfoTopLevelScope mod_info)
+
+	    filtered = filterOutChildren names
+	
+        things <- io $ mapM (GHC.lookupName s) filtered
+
+        dflags <- getDynFlags
+	let exts = dopt Opt_GlasgowExts dflags
+	io (putStrLn (showSDocForUser unqual (
+		vcat (map (pprTyThingInContext exts) (catMaybes things))
+	   )))
+	-- ToDo: modInfoInstances currently throws an exception for
+	-- package modules.  When it works, we can do this:
+	--	$$ vcat (map GHC.pprInstance (GHC.modInfoInstances mod_info))
+
+-----------------------------------------------------------------------------
+-- 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
+  session <- getSession
+  (as,bs) <- separate session mods [] []
+  let bs' = if null as && prelude_mod `notElem` bs then prelude_mod:bs else bs
+  io (GHC.setContext session as bs')
+
+separate :: Session -> [String] -> [Module] -> [Module]
+  -> GHCi ([Module],[Module])
+separate session []           as bs = return (as,bs)
+separate session (('*':m):ms) as bs = do
+   let modl = GHC.mkModule m
+   b <- io (GHC.moduleIsInterpreted session modl)
+   if b then separate session ms (modl:as) bs
+   	else throwDyn (CmdLineError ("module '" ++ m ++ "' is not interpreted"))
+separate session (m:ms)       as bs = separate session ms as (GHC.mkModule m:bs)
+
+prelude_mod = GHC.mkModule "Prelude"
+
+
+addToContext mods = do
+  cms <- getSession
+  (as,bs) <- io (GHC.getContext cms)
+
+  (as',bs') <- separate cms mods [] []
+
+  let as_to_add = as' \\ (as ++ bs)
+      bs_to_add = bs' \\ (as ++ bs)
+
+  io (GHC.setContext cms (as ++ as_to_add) (bs ++ bs_to_add))
+
+
+removeFromContext mods = do
+  cms <- getSession
+  (as,bs) <- io (GHC.getContext 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)
+
+  io (GHC.setContext cms as' bs')
+
 ----------------------------------------------------------------------------
 -- Code for `:set'
 
@@ -398,8 +1040,8 @@ 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 (
@@ -408,34 +1050,44 @@ 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
-
-       if (not (null rest2)) 
-	  then io (putStrLn ("unknown option: `" ++ head rest2 ++ "'"))
-	  else do
-
-       mapM setOpt plus_opts
-
-       -- now, the GHC flags
-       io (do -- first, static flags
-	      leftovers <- processArgs static_flags minus_opts []
-
-	      -- then, dynamic flags
-	      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: " ++ 
+setCmd str
+  = case words str of
+	("args":args) -> setArgs args
+	("prog":prog) -> setProg prog
+	wds -> setOptions wds
+
+setArgs args = do
+  st <- getGHCiState
+  setGHCiState st{ args = args }
+
+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
+
+      -- then, dynamic flags
+      dflags <- getDynFlags
+      (dflags',leftovers) <- io $ GHC.parseDynamicFlags dflags minus_opts
+      setDynFlags dflags'
+
+        -- update things if the users wants more packages
+{- TODO:
+        let new_packages = pkgs_after \\ pkgs_before
+        when (not (null new_packages)) $
+  	   newPackages new_packages
+-}
+
+      if (not (null leftovers))
+		then throwDyn (CmdLineError ("unrecognised flags: " ++ 
 						unwords leftovers))
-		 else return ()
-         )
+		else return ()
+
 
 unsetOptions :: String -> GHCi ()
 unsetOptions str
@@ -445,14 +1097,14 @@ unsetOptions str
 	   (plus_opts, rest2)  = partition isPlus rest1
 
        if (not (null rest2)) 
-	  then io (putStrLn ("unknown option: `" ++ head rest2 ++ "'"))
+	  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
@@ -463,12 +1115,12 @@ isPlus _ = False
 
 setOpt ('+':str)
   = case strToGHCiOpt str of
-	Nothing -> io (putStrLn ("unknown option: `" ++ str ++ "'"))
+	Nothing -> io (putStrLn ("unknown option: '" ++ str ++ "'"))
 	Just o  -> setOption o
 
 unsetOpt ('+':str)
   = case strToGHCiOpt str of
-	Nothing -> io (putStrLn ("unknown option: `" ++ str ++ "'"))
+	Nothing -> io (putStrLn ("unknown option: '" ++ str ++ "'"))
 	Just o  -> unsetOption o
 
 strToGHCiOpt :: String -> (Maybe GHCiOption)
@@ -482,55 +1134,145 @@ optToStr ShowTiming = "s"
 optToStr ShowType   = "t"
 optToStr RevertCAFs = "r"
 
------------------------------------------------------------------------------
--- 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
-
+{- ToDo
+newPackages new_pkgs = do	-- The new packages are already in v_Packages
+  session <- getSession
+  io (GHC.setTargets session [])
+  io (GHC.load session Nothing)
+  dflags   <- getDynFlags
+  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
+  session <- getSession
+  let show_one ms = do m <- io (GHC.showModule session ms)
+		       io (putStrLn m)
+  graph <- io (GHC.getModuleGraph session)
+  mapM_ show_one graph
+
+showBindings = do
+  s <- getSession
+  unqual <- io (GHC.getPrintUnqual s)
+  bindings <- io (GHC.getBindings s)
+  mapM_ showTyThing bindings
+  return ()
+
+showTyThing (AnId id) = do 
+  ty' <- cleanType (GHC.idType id)
+  str <- showForUser (ppr id <> text " :: " <> ppr ty')
+  io (putStrLn str)
+showTyThing _  = return ()
+
+-- if -fglasgow-exts is on we show the foralls, otherwise we don't.
+cleanType :: Type -> GHCi Type
+cleanType ty = do
+  dflags <- getDynFlags
+  if dopt Opt_GlasgowExts dflags 
+	then return ty
+	else return $! GHC.dropForAlls ty
+
+-- -----------------------------------------------------------------------------
+-- Completion
+
+#ifdef USE_READLINE
+completeWord :: String -> Int -> Int -> IO (Maybe (String, [String]))
+completeWord w start end = do
+  line <- Readline.getLineBuffer
+  case w of 
+     ':':_ | all isSpace (take (start-1) line) -> wrapCompleter completeCmd w
+     _other
+	| Just c <- is_cmd line -> do
+	   maybe_cmd <- lookupCommand c
+	   case maybe_cmd of
+	     Nothing -> return Nothing
+	     Just (_,_,complete) -> wrapCompleter complete w
+	| otherwise     -> do
+		--printf "complete %s, start = %d, end = %d\n" w start end
+		wrapCompleter completeIdentifier w
+
+is_cmd line 
+ | ((':':w) : _) <- words (dropWhile isSpace line) = Just w
+ | otherwise = Nothing
+
+completeNone w = return []
+
+completeCmd w = do
+  cmds <- readIORef commands
+  return (filter (w `isPrefixOf`) (map (':':) (map cmdName cmds)))
+
+completeIdentifier w = do
+  s <- restoreSession
+  rdrs <- GHC.getRdrNamesInScope s
+  return (filter (w `isPrefixOf`) (map (showSDoc.ppr) rdrs))
+
+completeModule w = do
+  s <- restoreSession
+  dflags <- GHC.getSessionDynFlags s
+  let pkg_mods = allExposedModules dflags
+  return (filter (w `isPrefixOf`) (map (showSDoc.ppr) pkg_mods))
+
+completeHomeModule w = do
+  s <- restoreSession
+  g <- GHC.getModuleGraph s
+  let home_mods = map GHC.ms_mod g
+  return (filter (w `isPrefixOf`) (map (showSDoc.ppr) home_mods))
+
+completeFilename = Readline.filenameCompletionFunction
+
+completeHomeModuleOrFile = unionComplete completeHomeModule completeFilename
+
+unionComplete :: (String -> IO [String]) -> (String -> IO [String]) -> String -> IO [String]
+unionComplete f1 f2 w = do
+  s1 <- f1 w
+  s2 <- f2 w
+  return (s1 ++ s2)
+
+wrapCompleter :: (String -> IO [String]) -> String -> IO (Maybe (String,[String]))
+wrapCompleter fun w =  do
+  strs <- fun w
+  case strs of
+    []  -> return Nothing
+    [x] -> return (Just (x,[]))
+    xs  -> case getCommonPrefix xs of
+		""   -> return (Just ("",xs))
+		pref -> return (Just (pref,xs))
+
+getCommonPrefix :: [String] -> String
+getCommonPrefix [] = ""
+getCommonPrefix (s:ss) = foldl common s ss
+  where common s "" = s
+	common "" s = ""
+	common (c:cs) (d:ds)
+	   | c == d = c : common cs ds
+	   | otherwise = ""
+
+allExposedModules :: DynFlags -> [Module]
+allExposedModules dflags 
+ = map GHC.mkModule (concat (map exposedModules (filter exposed (eltsUFM pkg_db))))
+ where
+  pkg_db = pkgIdMap (pkgState dflags)
+#endif
 
 -----------------------------------------------------------------------------
 -- GHCi monad
 
 data GHCiState = GHCiState
      { 
-	modules	       :: [Module],
-	current_module :: Module,
-	target         :: Maybe FilePath,
-	cmstate        :: CmState,
-	options        :: [GHCiOption],
-        last_expr      :: Maybe String
+	progname       :: String,
+	args	       :: [String],
+	session        :: GHC.Session,
+	options        :: [GHCiOption]
      }
 
 data GHCiOption 
@@ -539,20 +1281,37 @@ data GHCiOption
 	| RevertCAFs		-- revert CAFs after every evaluation
 	deriving Eq
 
-defaultCurrentModuleName = mkModuleName "Prelude"
-GLOBAL_VAR(defaultCurrentModule, error "no defaultCurrentModule", Module)
-
-GLOBAL_VAR(flush_stdout, error "no flush_stdout", HValue)
-GLOBAL_VAR(flush_stderr, error "no flush_stdout", HValue)
+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...
+getSession = getGHCiState >>= return . session
+
+GLOBAL_VAR(saved_sess, no_saved_sess, Session)
+no_saved_sess = error "no saved_ses"
+saveSession = getSession >>= io . writeIORef saved_sess
+splatSavedSession = io (writeIORef saved_sess no_saved_sess)
+restoreSession = readIORef saved_sess
+
+getDynFlags = do
+  s <- getSession
+  io (GHC.getSessionDynFlags s)
+setDynFlags dflags = do 
+  s <- getSession 
+  io (GHC.setSessionDynFlags s dflags)
 
 isOptionSet :: GHCiOption -> GHCi Bool
 isOptionSet opt
@@ -569,15 +1328,8 @@ unsetOption opt
  = do st <- getGHCiState
       setGHCiState (st{ options = filter (/= opt) (options st) })
 
-getLastExpr :: GHCi (Maybe String)
-getLastExpr
- = do st <- getGHCiState ; return (last_expr st)
-
-setLastExpr :: Maybe String -> GHCi ()
-setLastExpr last_expr
- = do st <- getGHCiState ; setGHCiState (st{last_expr = last_expr})
-
-io m = GHCi $ \s -> m >>= \a -> return (s,a)
+io :: IO a -> GHCi a
+io m = GHCi { unGHCi = \s -> m >>= return }
 
 -----------------------------------------------------------------------------
 -- recursive exception handlers
@@ -589,40 +1341,12 @@ io m = GHCi $ \s -> m >>= \a -> return (s,a)
 ghciHandle :: (Exception -> GHCi a) -> GHCi a -> GHCi a
 ghciHandle h (GHCi m) = GHCi $ \s -> 
    Exception.catch (m s) 
-	(\e -> unGHCi (ghciHandle h (ghciUnblock (h e))) s)
+	(\e -> unGHCi (ghciUnblock (h e)) s)
 
 ghciUnblock :: GHCi a -> GHCi a
 ghciUnblock (GHCi a) = GHCi $ \s -> Exception.unblock (a 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
-
------------------------------------------------------------------------------
 -- timing & statistics
 
 timeIt :: GHCi a -> GHCi a
@@ -635,20 +1359,42 @@ timeIt action
 		  a <- action
 		  allocs2 <- io $ getAllocations
 		  time2   <- io $ getCPUTime
-		  io $ printTimes (allocs2 - allocs1) (time2 - time1)
+		  io $ printTimes (fromIntegral (allocs2 - allocs1)) 
+				  (time2 - time1)
 		  return a
 
-foreign import "getAllocations" getAllocations :: IO Int
+foreign import ccall unsafe "getAllocations" getAllocations :: IO Int64
+	-- defined in ghc/rts/Stats.c
 
-printTimes :: Int -> Integer -> IO ()
+printTimes :: Integer -> Integer -> IO ()
 printTimes allocs psecs
    = do let secs = (fromIntegral psecs / (10^12)) :: Float
 	    secs_str = showFFloat (Just 2) secs
 	putStrLn (showSDoc (
 		 parens (text (secs_str "") <+> text "secs" <> comma <+> 
-			 int allocs <+> text "bytes")))
+			 text (show allocs) <+> text "bytes")))
 
 -----------------------------------------------------------------------------
 -- reverting CAFs
 	
-foreign import revertCAFs :: IO ()	-- make it "safe", just in case
+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
+
+-- -----------------------------------------------------------------------------
+-- Utils
+
+expandPath :: String -> GHCi String
+expandPath path = 
+  case dropWhile isSpace path of
+   ('~':d) -> do
+	tilde <- io (getEnv "HOME")	-- will fail if HOME not defined
+	return (tilde ++ '/':d)
+   other -> 
+	return other