X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fghci%2FInteractiveUI.hs;h=68147c06c3b875ddca144dbc405fcbcb471dfcd8;hb=41d0a61d29cb0daccbcdbf96a339c06c5aa140a4;hp=4f16a568ac7635aa6edf84e01b933f34a21c430d;hpb=459e7bd4622ea5bb8e90511b5fc6c7d8058dbd5f;p=ghc-hetmet.git

diff --git a/ghc/compiler/ghci/InteractiveUI.hs b/ghc/compiler/ghci/InteractiveUI.hs
index 4f16a56..68147c0 100644
--- a/ghc/compiler/ghci/InteractiveUI.hs
+++ b/ghc/compiler/ghci/InteractiveUI.hs
@@ -1,5 +1,5 @@
 -----------------------------------------------------------------------------
--- $Id: InteractiveUI.hs,v 1.4 2000/11/17 16:53:27 simonmar Exp $
+-- $Id: InteractiveUI.hs,v 1.53 2001/02/27 15:26:04 simonmar Exp $
 --
 -- GHC Interactive User Interface
 --
@@ -7,143 +7,294 @@
 --
 -----------------------------------------------------------------------------
 
-module InteractiveUI (interactiveUI) where
+{-# OPTIONS -#include "Linker.h" #-}
+module InteractiveUI ( interactiveUI, ghciWelcomeMsg ) where
 
 #include "HsVersions.h"
 
 import CompManager
 import CmStaticInfo
+import ByteCodeLink
 import DriverFlags
-import DriverUtil
 import DriverState
+import DriverUtil
 import Linker
-import Module
-import Panic
 import Util
+import Name		( Name )
+import Outputable
+import Panic		( GhcException(..) )
+import Config
 
 import Exception
+import Dynamic
+#ifndef NO_READLINE
 import Readline
+#endif
 import IOExts
 
+import Numeric
+import List
 import System
+import CPUTime
 import Directory
 import IO
 import Char
+import Monad 		( when )
+
+import PrelGHC 		( unsafeCoerce# )
+import Foreign		( nullPtr )
+import CString		( peekCString )
 
 -----------------------------------------------------------------------------
 
 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 ())]
-commands = [
-  ("cd",    	changeDirectory),
-  ("help",	help),
-  ("?",		help),
-  ("load",	loadModule),
-  ("reload",	reloadModule),
-  ("set",	setOptions),
-  ("type",	typeOfExpr),
-  ("quit",	quit),
-  ("!",		shellEscape)
+\   ___         ___ _\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",	keepGoing addModule),
+  ("cd",    	keepGoing changeDirectory),
+  ("def",	keepGoing defineMacro),
+  ("help",	keepGoing help),
+  ("?",		keepGoing help),
+  ("load",	keepGoing loadModule),
+  ("module",	keepGoing setContext),
+  ("reload",	keepGoing reloadModule),
+  ("set",	keepGoing setOptions),
+  ("type",	keepGoing typeOfExpr),
+  ("unset",	keepGoing unsetOptions),
+  ("undef",     keepGoing undefineMacro),
+  ("quit",	quit)
   ]
 
+keepGoing :: (String -> GHCi ()) -> (String -> GHCi Bool)
+keepGoing a str = a str >> return False
+
 shortHelpText = "use :? for help.\n"
 
 helpText = "\ 
-\   <expr>		evaluate <expr>\n\ 
+\ Commands available from the prompt:\n\ 
+\\  
+\   <stmt>		evaluate/run <stmt>\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\ 
-\   :?			display this list of commands\n\ 
+\   :help, :?		display this list of commands\n\ 
 \   :load <filename>    load a module (and it dependents)\n\ 
-\   :reload		reload the current program\n\ 
-\   :set <opetion> ...	set options\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 -> IO ()
-interactiveUI st = do
-   hPutStrLn stdout ghciWelcomeMsg
+interactiveUI :: CmState -> Maybe FilePath -> [LibrarySpec] -> IO ()
+interactiveUI cmstate mod cmdline_libs = do
    hFlush stdout
    hSetBuffering stdout NoBuffering
 
    -- link in the available packages
    pkgs <- getPackageInfo
-   linkPackages (reverse pkgs)
+   initLinker
+   linkPackages cmdline_libs (reverse pkgs)
+
+   (cmstate, ok, mods) <-
+   	case mod of
+	     Nothing  -> return (cmstate, True, [])
+	     Just m -> cmLoadModule cmstate m
 
 #ifndef NO_READLINE
    Readline.initialize
 #endif
-   _ <- (unGHCi uiLoop) GHCiState{ current_module = mkModuleName "Main", 
-	  	                   target = Nothing,
-			           cmstate = st }
+
+   dflags <- getDynFlags
+
+   (cmstate, maybe_hval) 
+	<- cmCompileExpr cmstate dflags "IO.hFlush PrelHandle.stderr"
+   case maybe_hval of
+	Just hval -> writeIORef flush_stderr (unsafeCoerce# hval :: IO ())
+	_ -> panic "interactiveUI:stderr"
+
+   (cmstate, maybe_hval) 
+	<- cmCompileExpr cmstate dflags "IO.hFlush PrelHandle.stdout"
+   case maybe_hval of
+	Just hval -> writeIORef flush_stdout (unsafeCoerce# hval :: IO ())
+	_ -> panic "interactiveUI:stdout"
+
+   (unGHCi runGHCi) GHCiState{ target = mod,
+			       cmstate = cmstate,
+			       options = [ShowTiming] }
    return ()
 
-uiLoop :: GHCi ()
-uiLoop = do
-  st <- getGHCiState
+
+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
+
+  -- read commands from stdin
 #ifndef NO_READLINE
-  l <- io (readline (moduleNameUserString (current_module st)  ++ "> "))
+  readlineLoop
 #else
-  l <- io (hGetLine stdin)
+  fileLoop stdin True
 #endif
-  case l of
-    Nothing -> return ()
-    Just "" -> uiLoop
-    Just l  -> do
+
+  -- and finally, exit
+  io $ do putStrLn "Leaving GHCi." 
+
+
+fileLoop :: Handle -> Bool -> GHCi ()
+fileLoop hdl prompt = do
+   st <- getGHCiState
+   mod <- io (cmGetContext (cmstate st))
+   when prompt (io (hPutStr hdl (mod ++ "> ")))
+   l <- io (IO.try (hGetLine hdl))
+   case l of
+	Left e | isEOFError e -> return ()
+	       | otherwise    -> throw 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
+   st <- getGHCiState
+   case remove_spaces s of
+	"" -> stringLoop ss
+	l  -> do quit <- runCommand l
+                 if quit then return () else stringLoop ss
+
 #ifndef NO_READLINE
-          io (addHistory l)
+readlineLoop :: GHCi ()
+readlineLoop = do
+   st <- getGHCiState
+   mod <- io (cmGetContext (cmstate st))
+   l <- io (readline (mod ++ "> "))
+   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
-  	  runCommand l
-	  uiLoop  
 
--- Top level exception handler, just prints out the exception and carries on.
+-- 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) )) $
-  ghciHandleDyn
-    (\dyn -> case dyn of
-		PhaseFailed phase code ->
+  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.")
-		_ -> io (putStrLn (show (dyn :: BarfKind)))
-    ) $
+		    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 expr = do
-  st <- getGHCiState
-  dflags <- io (readIORef v_DynFlags)
-  (st, maybe_hvalue) <- 
-	io (cmGetExpr (cmstate st) dflags (current_module st) expr)
-  case maybe_hvalue of
-	Nothing -> return ()
-	Just hv -> io (cmRunExpr hv)
-{-
-  let (mod,'.':str) = break (=='.') expr
-  case cmLookupSymbol (mkOrig varName (mkModuleName mod) (_PK_ str)) (cmstate st) of
-	Nothing -> io (putStrLn "nothing.")
-	Just e  -> io (
-  return ()
--}
-
+doCommand ('-':'-':_) = return False	-- comments, useful in scripts
+doCommand stmt
+   = do timeIt (do stuff <- runStmt stmt; finishEvalExpr stuff)
+        return False
+
+-- Returns True if the expr was successfully parsed, renamed and
+-- typechecked.
+runStmt :: String -> GHCi (Maybe [Name])
+runStmt stmt
+ | null (filter (not.isSpace) stmt)
+ = return Nothing
+ | otherwise
+ = do st <- getGHCiState
+      dflags <- io (getDynFlags)
+      (new_cmstate, names) <- io (cmRunStmt (cmstate st) dflags stmt)
+      setGHCiState st{cmstate = new_cmstate}
+      return (Just names)
+
+-- possibly print the type and revert CAFs after evaluating an expression
+finishEvalExpr Nothing = return False
+finishEvalExpr (Just names)
+ = do b <- isOptionSet ShowType
+      st <- getGHCiState
+      when b (mapM_ (showTypeOfName (cmstate st)) names)
+
+      b <- isOptionSet RevertCAFs
+      io (when b revertCAFs)
+      flushEverything
+      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))
+
+flushEverything :: GHCi ()
+flushEverything
+   = io $ do flush_so <- readIORef flush_stdout
+     	     flush_so
+     	     flush_se <- readIORef flush_stdout
+     	     flush_se
+             return ()
+
+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 ("uknown command `:" ++ cmd ++ "'\n" 
-				    ++ shortHelpText)
+  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)
-     cs      -> io $ hPutStrLn stdout ("prefix " ++ cmd ++ 
-			    	       " matches multiple commands (" ++ 
+     cs      -> io (hPutStrLn stdout ("prefix " ++ cmd ++ 
+			    	      " matches multiple commands (" ++ 
 	         	     	       foldr1 (\a b -> a ++ ',':b) (map fst cs)
-					 ++ ")")
+					 ++ ")") >> return False)
 
 noArgs c = io (hPutStrLn stdout ("command `:" ++ c ++ "' takes no arguments"))
 
@@ -153,71 +304,240 @@ 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 str
+  = do st <- getGHCiState
+       new_cmstate <- io (cmSetContext (cmstate st) str)
+       setGHCiState st{cmstate=new_cmstate}
+
 changeDirectory :: String -> GHCi ()
-changeDirectory = io . setCurrentDirectory
+changeDirectory d = io (setCurrentDirectory d)
+
+defineMacro :: String -> GHCi ()
+defineMacro s = do
+  let (macro_name, definition) = break isSpace s
+  cmds <- io (readIORef commands)
+  if (null macro_name) 
+	then throwDyn (OtherError "invalid macro name") 
+	else do
+  if (macro_name `elem` map fst cmds) 
+	then throwDyn (OtherError 
+		("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
+  st <- getGHCiState
+  dflags <- io (getDynFlags)
+  (new_cmstate, maybe_hv) <- io (cmCompileExpr (cmstate st) dflags new_expr)
+  setGHCiState st{cmstate = new_cmstate}
+  case maybe_hv of
+	Nothing -> return ()
+	Just hv -> 
+	  do funs <- io (unsafeCoerce# hv :: IO [HValue])
+	     case funs of
+		[fun] -> io (writeIORef commands 	
+		 		((macro_name, keepGoing (runMacro fun))
+				 : cmds))
+		_ -> throwDyn (OtherError "defineMacro: bizarre")
+
+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 (OtherError
+		("command `" ++ macro_name ++ "' cannot be undefined"))
+	else do
+  if (macro_name `notElem` map fst cmds) 
+	then throwDyn (OtherError 
+		("command `" ++ macro_name ++ "' not defined"))
+	else do
+  io (writeIORef commands (filter ((/= macro_name) . fst) cmds))
 
 loadModule :: String -> GHCi ()
-loadModule path = do
+loadModule path = timeIt (loadModule' path)
+
+loadModule' path = do
   state <- getGHCiState
-  (new_cmstate, mod) <- io (cmLoadModule (cmstate state) 
-				({-ToDo!!-}mkModuleName path))
-  let new_state = GHCiState {
-  			cmstate = new_cmstate,
-			current_module = case mod of 
-					   Nothing -> current_module state
-					   Just m  -> m,
-			target = Just path
-		   }
+  cmstate1 <- io (cmUnload (cmstate state))
+  io (revertCAFs)			-- always revert CAFs on load.
+  (cmstate2, ok, mods) <- io (cmLoadModule cmstate1 path)
+  let new_state = state{ cmstate = cmstate2,
+			 target = Just path
+		       }
   setGHCiState new_state
+  modulesLoadedMsg ok mods
 
 reloadModule :: String -> GHCi ()
 reloadModule "" = do
   state <- getGHCiState
   case target state of
-	Nothing -> io (putStr "no current target\n")
-	Just path -> do (new_cmstate, mod) <- io (cmLoadModule (cmstate state) (mkModuleName path))
-  			setGHCiState state{cmstate=new_cmstate}  
+   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)
+            setGHCiState state{ cmstate=new_cmstate }
+	    modulesLoadedMsg ok mods
+
 reloadModule _ = noArgs ":reload"
 
+
+modulesLoadedMsg ok mods = do
+  let mod_commas 
+	| null mods = text "none."
+	| otherwise = hsep (
+	    punctuate comma (map text 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)))
+
+
+typeOfExpr :: String -> GHCi ()
+typeOfExpr str 
+  = do st <- getGHCiState
+       dflags <- io (getDynFlags)
+       (new_cmstate, maybe_tystr) <- io (cmTypeOfExpr (cmstate st) dflags str)
+       setGHCiState st{cmstate = new_cmstate}
+       case maybe_tystr of
+	  Nothing    -> return ()
+	  Just tystr -> io (putStrLn tystr)
+
+quit :: String -> GHCi Bool
+quit _ = return True
+
+shellEscape :: String -> GHCi Bool
+shellEscape str = io (system str >> return False)
+
+----------------------------------------------------------------------------
+-- Code for `:set'
+
 -- set options in the interpreter.  Syntax is exactly the same as the
 -- ghc command line, except that certain options aren't available (-C,
 -- -E etc.)
 --
 -- This is pretty fragile: most options won't work as expected.  ToDo:
 -- figure out which ones & disallow them.
+
 setOptions :: String -> GHCi ()
-setOptions str =
-   io (do leftovers <- processArgs static_flags (words str) []
-	  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: " ++ 
+setOptions ""
+  = do st <- getGHCiState
+       let opts = options st
+       io $ putStrLn (showSDoc (
+   	      text "options currently set: " <> 
+   	      if null opts
+   		   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: " ++ 
 						unwords leftovers))
-		else return ()
-   )
-
-typeOfExpr :: String -> GHCi ()
-typeOfExpr = panic "typeOfExpr"
-
-quit :: String -> GHCi ()
-quit _ = return ()
-
-shellEscape :: String -> GHCi ()
-shellEscape str = io (system str >> return ())
+		 else return ()
+         )
+
+unsetOptions :: String -> GHCi ()
+unsetOptions 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 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")
+	  else return ()
+
+isMinus ('-':s) = True
+isMinus _ = False
+
+isPlus ('+':s) = True
+isPlus _ = False
+
+setOpt ('+':str)
+  = case strToGHCiOpt str of
+	Nothing -> io (putStrLn ("unknown option: `" ++ str ++ "'"))
+	Just o  -> setOption o
+
+unsetOpt ('+':str)
+  = case strToGHCiOpt str of
+	Nothing -> io (putStrLn ("unknown option: `" ++ str ++ "'"))
+	Just o  -> unsetOption o
+
+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"
+optToStr RevertCAFs = "r"
 
 -----------------------------------------------------------------------------
 -- GHCi monad
 
 data GHCiState = GHCiState
      { 
-	current_module :: ModuleName,
 	target         :: Maybe FilePath,
-	cmstate        :: CmState
+	cmstate        :: CmState,
+	options        :: [GHCiOption]
      }
 
+data GHCiOption 
+	= ShowTiming		-- show time/allocs after evaluation
+	| ShowType		-- show the type of expressions
+	| RevertCAFs		-- revert CAFs after every evaluation
+	deriving Eq
+
+GLOBAL_VAR(flush_stdout, error "no flush_stdout", IO ())
+GLOBAL_VAR(flush_stderr, error "no flush_stdout", IO ())
+
 newtype GHCi a = GHCi { unGHCi :: GHCiState -> IO (GHCiState, a) }
 
 instance Monad GHCi where
@@ -227,37 +547,147 @@ instance Monad GHCi where
 getGHCiState   = GHCi $ \s -> return (s,s)
 setGHCiState s = GHCi $ \_ -> return (s,())
 
+isOptionSet :: GHCiOption -> GHCi Bool
+isOptionSet opt
+ = do st <- getGHCiState
+      return (opt `elem` options st)
+
+setOption :: GHCiOption -> GHCi ()
+setOption opt
+ = do st <- getGHCiState
+      setGHCiState (st{ options = opt : filter (/= opt) (options st) })
+
+unsetOption :: GHCiOption -> GHCi ()
+unsetOption opt
+ = do st <- getGHCiState
+      setGHCiState (st{ options = filter (/= opt) (options st) })
+
 io m = GHCi $ \s -> m >>= \a -> return (s,a)
 
+-----------------------------------------------------------------------------
+-- recursive exception handlers
+
+-- 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 (ghciHandle h (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
+-- Left: full path name of a .o file, including trailing .o
+-- Right: "unadorned" name of a .DLL/.so
+--        e.g.    On unix     "qt"  denotes "libqt.so"
+--                On WinDoze  "burble"  denotes "burble.DLL"
+--        addDLL is platform-specific and adds the lib/.so/.DLL
+--        prefixes plaform-dependently; we don't do that here.
+type LibrarySpec
+   = Either FilePath String
+
+showLS (Left nm)  = "(static) " ++ nm
+showLS (Right nm) = "(dynamic) " ++ nm
+
+linkPackages :: [LibrarySpec] -> [Package] -> IO ()
+linkPackages cmdline_lib_specs pkgs
+   = do mapM_ linkPackage pkgs
+        mapM_ preloadLib cmdline_lib_specs
+     where
+        preloadLib lib_spec
+           = do putStr ("Loading object " ++ showLS lib_spec ++ " ... ")
+                case lib_spec of
+                   Left static_ish
+                      -> do b <- doesFileExist static_ish
+                            if    not b
+                             then do putStr "not found.\n"
+                                     croak
+                             else do loadObj static_ish
+                                     putStr "done.\n"
+                   Right dll_unadorned
+                      -> do maybe_errmsg <- addDLL dll_unadorned
+                            if    maybe_errmsg == nullPtr
+                             then putStr "done.\n"
+                             else do str <- peekCString maybe_errmsg
+                                     putStr ("failed (" ++ str ++ ")\n")
+                                     croak
+
+        croak = throwDyn (OtherError "user specified .o/.so/.DLL could not be loaded.")
+
 
 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
+linkPackage pkg 
+   | name pkg `elem` ["rts", "gmp"] 
+   = return ()
+   | otherwise
+   = do putStr ("Loading package " ++ name pkg ++ " ... ")
+        -- For each obj, try obj.o and if that fails, obj.so.
+        -- Complication: all the .so's must be loaded before any of the .o's.  
+        let dirs      =  library_dirs pkg
+        let objs      =  hs_libraries pkg ++ extra_libraries pkg
+        classifieds   <- mapM (locateOneObj dirs) objs
+        let sos_first = filter isRight classifieds 
+                        ++ filter (not.isRight) classifieds
+        mapM loadClassified sos_first
+        putStr "linking ... "
+        resolveObjs
+        putStrLn "done."
+     where
+        isRight (Right _) = True
+        isRight (Left _)  = False
+
+loadClassified :: LibrarySpec -> IO ()
+loadClassified (Left obj_absolute_filename)
+   = do loadObj obj_absolute_filename
+loadClassified (Right dll_unadorned)
+   = do maybe_errmsg <- addDLL dll_unadorned
+        if    maybe_errmsg == nullPtr
+         then return ()
+         else do str <- peekCString maybe_errmsg
+                 throwDyn (OtherError ("can't find .o or .so/.DLL for: " 
+                                       ++ dll_unadorned ++ " (" ++ str ++ ")" ))
+
+locateOneObj :: [FilePath] -> String -> IO LibrarySpec
+locateOneObj []     obj 
+   = return (Right obj) -- we assume
+locateOneObj (d:ds) obj 
+   = do let path = d ++ '/':obj ++ ".o"
+        b <- doesFileExist path
+        if b then return (Left path) else locateOneObj ds obj
+
+-----------------------------------------------------------------------------
+-- timing & statistics
+
+timeIt :: GHCi a -> GHCi a
+timeIt action
+  = do b <- isOptionSet ShowTiming
+       if not b 
+	  then action 
+	  else do allocs1 <- io $ getAllocations
+		  time1   <- io $ getCPUTime
+		  a <- action
+		  allocs2 <- io $ getAllocations
+		  time2   <- io $ getCPUTime
+		  io $ printTimes (allocs2 - allocs1) (time2 - time1)
+		  return a
+
+foreign import "getAllocations" getAllocations :: IO Int
+
+printTimes :: Int -> 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")))
+
+-----------------------------------------------------------------------------
+-- reverting CAFs
+	
+foreign import revertCAFs :: IO ()	-- make it "safe", just in case