X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fghci%2FInteractiveUI.hs;h=ec1f4bf98e892080e81cd0c69650f2ea552883ab;hb=9efeaae7dd6d720b0f44b0a73ed4881d7eb41034;hp=8066aa4c082c350d078462ed541592c8ff3fd99e;hpb=c5f6a3c65987b467cb64be30abd7a10ea6280b67;p=ghc-hetmet.git

diff --git a/compiler/ghci/InteractiveUI.hs b/compiler/ghci/InteractiveUI.hs
index 8066aa4..ec1f4bf 100644
--- a/compiler/ghci/InteractiveUI.hs
+++ b/compiler/ghci/InteractiveUI.hs
@@ -6,45 +6,51 @@
 -- (c) The GHC Team 2005-2006
 --
 -----------------------------------------------------------------------------
-module InteractiveUI ( 
-	interactiveUI,
-	ghciWelcomeMsg
-   ) where
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
+module InteractiveUI ( interactiveUI, ghciWelcomeMsg ) where
 
 #include "HsVersions.h"
 
 import GhciMonad
 import GhciTags
+import Debugger
 
 -- The GHC interface
 import qualified GHC
 import GHC              ( Session, LoadHowMuch(..), Target(..),  TargetId(..),
                           Type, Module, ModuleName, TyThing(..), Phase,
-                          BreakIndex, Name, SrcSpan )
-import Debugger
+                          BreakIndex, SrcSpan, Resume, SingleStep )
+import PprTyThing
 import DynFlags
 import Packages
 import PackageConfig
 import UniqFM
-import PprTyThing
+import HscTypes		( implicitTyThings )
 import Outputable       hiding (printForUser)
 import Module           -- for ModuleEnv
+import Name
+import SrcLoc
 
 -- Other random utilities
 import Digraph
 import BasicTypes hiding (isTopLevel)
 import Panic      hiding (showException)
-import FastString       ( unpackFS )
 import Config
 import StaticFlags
 import Linker
 import Util
+import NameSet
+import Maybes		( orElse )
+import FastString
 
 #ifndef mingw32_HOST_OS
-import System.Posix
-#if __GLASGOW_HASKELL__ > 504
-	hiding (getEnv)
-#endif
+import System.Posix hiding (getEnv)
 #else
 import GHC.ConsoleHandler ( flushConsole )
 import System.Win32	  ( setConsoleCP, setConsoleOutputCP )
@@ -70,10 +76,12 @@ import System.Exit	( exitWith, ExitCode(..) )
 import System.Directory
 import System.IO
 import System.IO.Error as IO
+import System.IO.Unsafe
 import Data.Char
 import Data.Dynamic
 import Data.Array
 import Control.Monad as Monad
+import Text.Printf
 
 import Foreign.StablePtr	( newStablePtr )
 import GHC.Exts		( unsafeCoerce# )
@@ -85,12 +93,9 @@ import System.Posix.Internals ( setNonBlockingFD )
 
 -----------------------------------------------------------------------------
 
-ghciWelcomeMsg =
- "   ___         ___ _\n"++
- "  / _ \\ /\\  /\\/ __(_)\n"++
- " / /_\\// /_/ / /  | |      GHC Interactive, version " ++ cProjectVersion ++ ", for Haskell 98.\n"++
- "/ /_\\\\/ __  / /___| |      http://www.haskell.org/ghc/\n"++
- "\\____/\\/ /_/\\____/|_|      Type :? for help.\n"
+ghciWelcomeMsg :: String
+ghciWelcomeMsg = "GHCi, version " ++ cProjectVersion ++
+                 ": http://www.haskell.org/ghc/  :? for help"
 
 type Command = (String, String -> GHCi Bool, Bool, String -> IO [String])
 cmdName (n,_,_,_) = n
@@ -102,33 +107,41 @@ builtin_commands = [
 	-- Hugs users are accustomed to :e, so make sure it doesn't overlap
   ("?",		keepGoing help,			False, completeNone),
   ("add",	keepGoingPaths addModule,	False, completeFilename),
+  ("abandon",   keepGoing abandonCmd,           False, completeNone),
   ("break",     keepGoing breakCmd,             False, completeIdentifier),
+  ("back",      keepGoing backCmd,              False, completeNone),
   ("browse",    keepGoing browseCmd,		False, completeModule),
   ("cd",    	keepGoing changeDirectory,	False, completeFilename),
   ("check",	keepGoing checkModule,		False, completeHomeModule),
-  ("continue",  continueCmd,                    False, completeNone),
+  ("continue",  keepGoing continueCmd,          False, completeNone),
+  ("cmd",       keepGoing cmdCmd,               False, completeIdentifier),
   ("ctags",	keepGoing createCTagsFileCmd, 	False, completeFilename),
   ("def",	keepGoing defineMacro,		False, completeIdentifier),
   ("delete",    keepGoing deleteCmd,            False, completeNone),
   ("e", 	keepGoing editFile,		False, completeFilename),
   ("edit",	keepGoing editFile,		False, completeFilename),
   ("etags",	keepGoing createETagsFileCmd,	False, completeFilename),
-  ("force",     keepGoing (pprintClosureCommand False True), False, completeIdentifier),
+  ("force",     keepGoing forceCmd,             False, completeIdentifier),
+  ("forward",   keepGoing forwardCmd,           False, completeNone),
   ("help",	keepGoing help,			False, completeNone),
+  ("history",   keepGoing historyCmd,           False, completeNone), 
   ("info",      keepGoing info,			False, completeIdentifier),
   ("kind",	keepGoing kindOfType,		False, completeIdentifier),
   ("load",	keepGoingPaths loadModule_,     False, completeHomeModuleOrFile),
   ("list",	keepGoing listCmd,              False, completeNone),
   ("module",	keepGoing setContext,		False, completeModule),
   ("main",	keepGoing runMain,		False, completeIdentifier),
-  ("print",     keepGoing (pprintClosureCommand True False), False, completeIdentifier),
+  ("print",     keepGoing printCmd,             False, completeIdentifier),
   ("quit",	quit,				False, completeNone),
   ("reload", 	keepGoing reloadModule,  	False, completeNone),
   ("set",	keepGoing setCmd,		True,  completeSetOptions),
   ("show",	keepGoing showCmd,		False, completeNone),
-  ("sprint",    keepGoing (pprintClosureCommand False False),False, completeIdentifier),
-  ("step",      stepCmd,                        False, completeIdentifier), 
+  ("sprint",    keepGoing sprintCmd,            False, completeIdentifier),
+  ("step",      keepGoing stepCmd,              False, completeIdentifier), 
+  ("steplocal", keepGoing stepLocalCmd,         False, completeIdentifier), 
+  ("stepmodule",keepGoing stepModuleCmd,        False, completeIdentifier), 
   ("type",	keepGoing typeOfExpr,		False, completeIdentifier),
+  ("trace",     keepGoing traceCmd,             False, completeIdentifier), 
   ("undef",     keepGoing undefineMacro,	False, completeMacro),
   ("unset",	keepGoing unsetOptions,		True,  completeSetOptions)
   ]
@@ -144,30 +157,51 @@ shortHelpText = "use :? for help.\n"
 helpText =
  " Commands available from the prompt:\n" ++
  "\n" ++
- "   <stmt>                      evaluate/run <stmt>\n" ++
+ "   <statement>                 evaluate/run <statement>\n" ++
  "   :add <filename> ...         add module(s) to the current target set\n" ++
- "   :break [<mod>] <l> [<col>]  set a breakpoint at the specified location\n" ++
- "   :break <name>               set a breakpoint on the specified function\n" ++
  "   :browse [*]<module>         display the names defined by <module>\n" ++
  "   :cd <dir>                   change directory to <dir>\n" ++
- "   :continue                   resume after a breakpoint\n" ++
+ "   :cmd <expr>                 run the commands returned by <expr>::IO String\n" ++
  "   :ctags [<file>]             create tags file for Vi (default: \"tags\")\n" ++
  "   :def <cmd> <expr>           define a command :<cmd>\n" ++
- "   :delete <number>            delete the specified breakpoint\n" ++
- "   :delete *                   delete all breakpoints\n" ++
  "   :edit <file>                edit file\n" ++
  "   :edit                       edit last module\n" ++
  "   :etags [<file>]             create tags file for Emacs (default: \"TAGS\")\n" ++
--- "   :force <expr>               print <expr>, forcing unevaluated parts\n" ++
  "   :help, :?                   display this list of commands\n" ++
  "   :info [<name> ...]          display information about the given names\n" ++
  "   :kind <type>                show the kind of <type>\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" ++
- "   :print [<name> ...]         prints a value without forcing its computation\n" ++
+ "   :module [+/-] [*]<mod> ...  set the context for expression evaluation\n" ++
  "   :quit                       exit GHCi\n" ++
  "   :reload                     reload the current module set\n" ++
+ "   :type <expr>                show the type of <expr>\n" ++
+ "   :undef <cmd>                undefine user-defined command :<cmd>\n" ++
+ "   :!<command>                 run the shell command <command>\n" ++
+ "\n" ++
+ " -- Commands for debugging:\n" ++
+ "\n" ++
+ "   :abandon                    at a breakpoint, abandon current computation\n" ++
+ "   :back                       go back in the history (after :trace)\n" ++
+ "   :break [<mod>] <l> [<col>]  set a breakpoint at the specified location\n" ++
+ "   :break <name>               set a breakpoint on the specified function\n" ++
+ "   :continue                   resume after a breakpoint\n" ++
+ "   :delete <number>            delete the specified breakpoint\n" ++
+ "   :delete *                   delete all breakpoints\n" ++
+ "   :force <expr>               print <expr>, forcing unevaluated parts\n" ++
+ "   :forward                    go forward in the history (after :back)\n" ++
+ "   :history [<n>]              show the last <n> items in the history (after :trace)\n" ++
+ "   :print [<name> ...]         prints a value without forcing its computation\n" ++
+ "   :sprint [<name> ...]        simplifed version of :print\n" ++
+ "   :step                       single-step after stopping at a breakpoint\n"++
+ "   :step <expr>                single-step into <expr>\n"++
+ "   :steplocal                  single-step restricted to the current top level decl.\n"++
+ "   :stepmodule                 single-step restricted to the current module\n"++
+ "   :trace                      trace after stopping at a breakpoint\n"++
+ "   :trace <expr>               trace into <expr> (remembers breakpoints for :history)\n"++
+
+ "\n" ++
+ " -- Commands for changing settings:\n" ++
  "\n" ++
  "   :set <option> ...           set options\n" ++
  "   :set args <arg> ...         set the arguments returned by System.getArgs\n" ++
@@ -175,29 +209,24 @@ helpText =
  "   :set prompt <prompt>        set the prompt used in GHCi\n" ++
  "   :set editor <cmd>           set the command used for :edit\n" ++
  "   :set stop <cmd>             set the command to run when a breakpoint is hit\n" ++
- "\n" ++
- "   :show breaks                show active breakpoints\n" ++
- "   :show context               show the breakpoint context\n" ++
- "   :show modules               show the currently loaded modules\n" ++
- "   :show bindings              show the current bindings made at the prompt\n" ++
- "\n" ++
- "   :sprint [<name> ...]        simplifed version of :print\n" ++
- "   :step                       single-step after stopping at a breakpoint\n"++
- "   :step <expr>                single-step into <expr>\n"++
- "   :type <expr>                show the type of <expr>\n" ++
- "   :undef <cmd>                undefine user-defined command :<cmd>\n" ++
  "   :unset <option> ...         unset options\n" ++
- "   :!<command>                 run the shell command <command>\n" ++
  "\n" ++
- " Options for ':set' and ':unset':\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" ++
+ "\n" ++
+ " -- Commands for displaying information:\n" ++
+ "\n" ++
+ "   :show bindings              show the current bindings made at the prompt\n" ++
+ "   :show breaks                show the active breakpoints\n" ++
+ "   :show context               show the breakpoint context\n" ++
+ "   :show modules               show the currently loaded modules\n" ++
+ "   :show <setting>             show anything that can be set with :set (e.g. args)\n" ++
  "\n" 
--- Todo: add help for breakpoint commands here
 
 findEditor = do
   getEnv "EDITOR" 
@@ -223,21 +252,22 @@ interactiveUI session srcs maybe_expr = do
    newStablePtr stdout
    newStablePtr stderr
 
-	-- Initialise buffering for the *interpreted* I/O system
+    -- Initialise buffering for the *interpreted* I/O system
    initInterpBuffering session
 
    when (isNothing maybe_expr) $ do
-	-- Only for GHCi (not runghc and ghc -e):
-	-- Turn buffering off for the compiled program's stdout/stderr
-	turnOffBuffering
-	-- Turn buffering off for GHCi's stdout
-	hFlush stdout
-	hSetBuffering stdout NoBuffering
-	-- 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
+        -- Only for GHCi (not runghc and ghc -e):
+
+        -- Turn buffering off for the compiled program's stdout/stderr
+        turnOffBuffering
+        -- Turn buffering off for GHCi's stdout
+        hFlush stdout
+        hSetBuffering stdout NoBuffering
+        -- 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
    prel_mod <- GHC.findModule session prel_name (Just basePackageId)
    GHC.setContext session [] [prel_mod]
 
@@ -266,9 +296,10 @@ interactiveUI session srcs maybe_expr = do
 		   session = session,
 		   options = [],
                    prelude = prel_mod,
-                   resume = [],
-                   breaks = emptyActiveBreakPoints,
-                   tickarrays = emptyModuleEnv
+                   break_ctr = 0,
+                   breaks = [],
+                   tickarrays = emptyModuleEnv,
+                   cmdqueue = []
                  }
 
 #ifdef USE_READLINE
@@ -328,28 +359,28 @@ runGHCi paths maybe_expr = do
   let show_prompt = verbosity dflags > 0 || is_tty
 
   case maybe_expr of
-	Nothing -> 
+        Nothing ->
           do
 #if defined(mingw32_HOST_OS)
-            -- The win32 Console API mutates the first character of 
+            -- 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 ()
+            case flushed of
+             Left err | isDoesNotExistError err -> return ()
+                      | otherwise -> io (ioError err)
+             Right () -> return ()
 #endif
-	    -- initialise the console if necessary
-	    io setUpConsole
+            -- initialise the console if necessary
+            io setUpConsole
 
-	    -- enter the interactive loop
-	    interactiveLoop is_tty show_prompt
-	Just expr -> do
-	    -- just evaluate the expression we were given
-	    runCommandEval expr
-	    return ()
+            -- 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."
@@ -411,10 +442,9 @@ checkPerms name =
 
 fileLoop :: Handle -> Bool -> GHCi ()
 fileLoop hdl show_prompt = do
-   session <- getSession
-   (mod,imports) <- io (GHC.getContext session)
-   st <- getGHCiState
-   when show_prompt (io (putStr (mkPrompt mod imports (resume st) (prompt st))))
+   when show_prompt $ do
+        prompt <- mkPrompt
+        (io (putStr prompt))
    l <- io (IO.try (hGetLine hdl))
    case l of
 	Left e | isEOFError e		   -> return ()
@@ -428,36 +458,43 @@ fileLoop hdl show_prompt = do
 	Right l -> 
 	  case removeSpaces l of
             "" -> fileLoop hdl show_prompt
-	    l  -> do quit <- runCommand l
+	    l  -> do quit <- runCommands l
                      if quit then return () else fileLoop hdl show_prompt
 
-stringLoop :: [String] -> GHCi Bool{-True: we quit-}
-stringLoop [] = return False
-stringLoop (s:ss) = do
-   case removeSpaces s of
-	"" -> stringLoop ss
-	l  -> do quit <- runCommand l
-                 if quit then return True else stringLoop ss
+mkPrompt = do
+  session <- getSession
+  (toplevs,exports) <- io (GHC.getContext session)
+  resumes <- io $ GHC.getResumeContext session
+
+  context_bit <-
+        case resumes of
+            [] -> return empty
+            r:rs -> do
+                let ix = GHC.resumeHistoryIx r
+                if ix == 0
+                   then return (brackets (ppr (GHC.resumeSpan r)) <> space)
+                   else do
+                        let hist = GHC.resumeHistory r !! (ix-1)
+                        span <- io$ GHC.getHistorySpan session hist
+                        return (brackets (ppr (negate ix) <> char ':' 
+                                          <+> ppr span) <> space)
+  let
+        dots | r:rs <- resumes, not (null rs) = text "... "
+             | otherwise = empty
+
+        modules_bit = 
+             hsep (map (\m -> char '*' <> ppr (GHC.moduleName m)) toplevs) <+>
+             hsep (map (ppr . GHC.moduleName) exports)
 
-mkPrompt toplevs exports resumes prompt
-  = showSDoc $ f prompt
-    where
-        f ('%':'s':xs) = perc_s <> f xs
+        deflt_prompt = dots <> context_bit <> modules_bit
+
+        f ('%':'s':xs) = deflt_prompt <> f xs
         f ('%':'%':xs) = char '%' <> f xs
         f (x:xs) = char x <> f xs
         f [] = empty
-    
-        perc_s
-          | (span,_,_):rest <- resumes 
-          = (if not (null rest) then text "... " else empty)
-            <> brackets (ppr span) <+> modules_prompt
-          | otherwise
-          = modules_prompt
-
-        modules_prompt = 
-             hsep (map (\m -> char '*' <> ppr (GHC.moduleName m)) toplevs) <+>
-             hsep (map (ppr . GHC.moduleName) exports)
-
+   --
+  st <- getGHCiState
+  return (showSDoc (f (prompt st)))
 
 
 #ifdef USE_READLINE
@@ -468,8 +505,9 @@ readlineLoop = do
    io yield
    saveSession -- for use by completion
    st <- getGHCiState
-   l <- io (readline (mkPrompt mod imports (resume st) (prompt st))
-	  	`finally` setNonBlockingFD 0)
+   mb_span <- getCurrentBreakSpan
+   prompt <- mkPrompt
+   l <- io (readline prompt `finally` setNonBlockingFD 0)
 		-- readline sometimes puts stdin into blocking mode,
 		-- so we need to put it back for the IO library
    splatSavedSession
@@ -480,17 +518,31 @@ readlineLoop = do
 	    "" -> readlineLoop
 	    l  -> do
         	  io (addHistory l)
-  	  	  quit <- runCommand l
+  	  	  quit <- runCommands l
           	  if quit then return () else readlineLoop
 #endif
 
-runCommand :: String -> GHCi Bool
-runCommand c = ghciHandle handler (doCommand c)
-  where 
-    doCommand (':' : command) = specialCommand command
-    doCommand stmt
-       = do timeIt (do nms <- runStmt stmt; finishEvalExpr nms)
-            return False
+runCommands :: String -> GHCi Bool
+runCommands cmd = do
+        q <- ghciHandle handler (doCommand cmd)
+        if q then return True else runNext
+  where
+       runNext = do
+          st <- getGHCiState
+          case cmdqueue st of
+            []   -> return False
+            c:cs -> do setGHCiState st{ cmdqueue = cs }
+                       runCommands c
+
+       doCommand (':' : cmd) = specialCommand cmd
+       doCommand stmt        = do timeIt $ runStmt stmt GHC.RunToCompletion
+                                  return False
+
+enqueueCommands :: [String] -> GHCi ()
+enqueueCommands cmds = do
+  st <- getGHCiState
+  setGHCiState st{ cmdqueue = cmds ++ cmdqueue st }
+
 
 -- This version is for the GHC command-line option -e.  The only difference
 -- from runCommand is that it catches the ExitException exception and
@@ -503,66 +555,96 @@ runCommandEval c = ghciHandle handleEval (doCommand c)
 
     doCommand (':' : command) = specialCommand command
     doCommand stmt
-       = do nms <- runStmt stmt
-	    case nms of 
-		Nothing -> io (exitWith (ExitFailure 1))
+       = do r <- runStmt stmt GHC.RunToCompletion
+	    case r of 
+		False -> io (exitWith (ExitFailure 1))
 		  -- failure to run the command causes exit(1) for ghc -e.
-		_       -> do finishEvalExpr nms
-                              return True
+		_       -> return True
 
-runStmt :: String -> GHCi (Maybe (Bool,[Name]))
-runStmt stmt
- | null (filter (not.isSpace) stmt) = return (Just (False,[]))
+runStmt :: String -> SingleStep -> GHCi Bool
+runStmt stmt step
+ | null (filter (not.isSpace) stmt) = return False
+ | ["import", mod] <- words stmt    = keepGoing setContext ('+':mod)
  | otherwise
  = do st <- getGHCiState
       session <- getSession
       result <- io $ withProgName (progname st) $ withArgs (args st) $
-	     	     GHC.runStmt session stmt
-      switchOnRunResult result
-
-switchOnRunResult :: GHC.RunResult -> GHCi (Maybe (Bool,[Name]))
-switchOnRunResult GHC.RunFailed = return Nothing
-switchOnRunResult (GHC.RunException e) = throw e
-switchOnRunResult (GHC.RunOk names) = return $ Just (False,names)
-switchOnRunResult (GHC.RunBreak threadId names info resume) = do
-   session <- getSession
-   Just mod_info <- io $ GHC.getModuleInfo session (GHC.breakInfo_module info) 
-   let modBreaks  = GHC.modInfoModBreaks mod_info
-   let ticks      = GHC.modBreaks_locs modBreaks
+	     	     GHC.runStmt session stmt step
+      afterRunStmt (const True) result
+
+
+--afterRunStmt :: GHC.RunResult -> GHCi Bool
+                                 -- False <=> the statement failed to compile
+afterRunStmt _ (GHC.RunException e) = throw e
+afterRunStmt step_here run_result = do
+  session     <- getSession
+  resumes <- io $ GHC.getResumeContext session
+  case run_result of
+     GHC.RunOk names -> do
+        show_types <- isOptionSet ShowType
+        when show_types $ printTypeOfNames session names
+     GHC.RunBreak _ names mb_info 
+         | isNothing  mb_info || 
+           step_here (GHC.resumeSpan $ head resumes) -> do
+               printForUser $ ptext SLIT("Stopped at") <+> 
+                       ppr (GHC.resumeSpan $ head resumes)
+--               printTypeOfNames session names
+               printTypeAndContentOfNames session names
+               maybe (return ()) runBreakCmd mb_info
+               -- run the command set with ":set stop <cmd>"
+               st <- getGHCiState
+               enqueueCommands [stop st]
+               return ()
+         | otherwise -> io(GHC.resume session GHC.SingleStep) >>= 
+                        afterRunStmt step_here >> return ()
+     _ -> return ()
 
-   -- display information about the breakpoint
-   let location = ticks ! GHC.breakInfo_number info
-   printForUser $ ptext SLIT("Stopped at") <+> ppr location
-
-   pushResume location threadId resume
-
-   -- run the command set with ":set stop <cmd>"
-   st <- getGHCiState
-   runCommand (stop st)
-
-   return (Just (True,names))
-
--- possibly print the type and revert CAFs after evaluating an expression
-finishEvalExpr mb_names
- = do show_types <- isOptionSet ShowType
-      session <- getSession
-      case mb_names of
-	Nothing    -> return ()      
-	Just (is_break,names) -> 
-                when (is_break || show_types) $
-                      mapM_ (showTypeOfName session) names
-
-      flushInterpBuffers
-      io installSignalHandlers
-      b <- isOptionSet RevertCAFs
-      io (when b revertCAFs)
-
-showTypeOfName :: Session -> Name -> GHCi ()
-showTypeOfName session n
+  flushInterpBuffers
+  io installSignalHandlers
+  b <- isOptionSet RevertCAFs
+  io (when b revertCAFs)
+
+  return (case run_result of GHC.RunOk _ -> True; _ -> False)
+
+      where printTypeAndContentOfNames session names = do
+              let namesSorted = sortBy compareNames names
+              tythings <- catMaybes `liftM` 
+                              io (mapM (GHC.lookupName session) namesSorted)
+	      let ids = [id | AnId id <- tythings]
+              terms <- mapM (io . GHC.obtainTermB session 10 False) ids
+              docs_terms <- mapM (io . showTerm session) terms                                   
+	      dflags <- getDynFlags
+	      let pefas = dopt Opt_PrintExplicitForalls dflags
+              printForUser $ vcat $ zipWith (\ty cts -> ty <+> equals <+> cts)
+                                            (map (pprTyThing pefas . AnId) ids)
+                                            docs_terms
+
+runBreakCmd :: GHC.BreakInfo -> GHCi ()
+runBreakCmd info = do
+  let mod = GHC.breakInfo_module info
+      nm  = GHC.breakInfo_number info
+  st <- getGHCiState
+  case  [ loc | (i,loc) <- breaks st,
+                breakModule loc == mod, breakTick loc == nm ] of
+        []  -> return ()
+        loc:_ | null cmd  -> return ()
+              | otherwise -> do enqueueCommands [cmd]; return ()
+              where cmd = onBreakCmd loc
+
+printTypeOfNames :: Session -> [Name] -> GHCi ()
+printTypeOfNames session names
+ = mapM_ (printTypeOfName session) $ sortBy compareNames names
+
+compareNames :: Name -> Name -> Ordering
+n1 `compareNames` n2 = compareWith n1 `compare` compareWith n2
+    where compareWith n = (getOccString n, getSrcSpan n)
+
+printTypeOfName :: Session -> Name -> GHCi ()
+printTypeOfName session n
    = do maybe_tything <- io (GHC.lookupName session n)
-	case maybe_tything of
-	  Nothing    -> return ()
-	  Just thing -> showTyThing thing
+        case maybe_tything of
+            Nothing    -> return ()
+            Just thing -> printTyThing thing
 
 specialCommand :: String -> GHCi Bool
 specialCommand ('!':str) = shellEscape (dropWhile isSpace str)
@@ -580,13 +662,47 @@ lookupCommand str = do
   -- 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
+     [] -> case [ c | c@(s,_,_,_) <- cmds, str `isPrefixOf` s ] of
      		[] -> return Nothing
      		c:_ -> return (Just c)
 
+
+getCurrentBreakSpan :: GHCi (Maybe SrcSpan)
+getCurrentBreakSpan = do
+  session <- getSession
+  resumes <- io $ GHC.getResumeContext session
+  case resumes of
+    [] -> return Nothing
+    (r:rs) -> do
+        let ix = GHC.resumeHistoryIx r
+        if ix == 0
+           then return (Just (GHC.resumeSpan r))
+           else do
+                let hist = GHC.resumeHistory r !! (ix-1)
+                span <- io $ GHC.getHistorySpan session hist
+                return (Just span)
+
+getCurrentBreakModule :: GHCi (Maybe Module)
+getCurrentBreakModule = do
+  session <- getSession
+  resumes <- io $ GHC.getResumeContext session
+  case resumes of
+    [] -> return Nothing
+    (r:rs) -> do
+        let ix = GHC.resumeHistoryIx r
+        if ix == 0
+           then return (GHC.breakInfo_module `liftM` GHC.resumeBreakInfo r)
+           else do
+                let hist = GHC.resumeHistory r !! (ix-1)
+                return $ Just $ GHC.getHistoryModule  hist
+
 -----------------------------------------------------------------------------
 -- Commands
 
+noArgs :: GHCi () -> String -> GHCi ()
+noArgs m "" = m
+noArgs m _ = io $ putStrLn "This command takes no arguments"
+
 help :: String -> GHCi ()
 help _ = io (putStr helpText)
 
@@ -595,30 +711,30 @@ 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 }
+	     ; let pefas = dopt Opt_PrintExplicitForalls dflags
+	     ; mapM_ (infoThing pefas 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
+    infoThing pefas session str = io $ do
+	names     <- GHC.parseName session str
+	mb_stuffs <- mapM (GHC.getInfo session) names
+	let filtered = filterOutChildren (\(t,f,i) -> t) (catMaybes mb_stuffs)
 	unqual <- GHC.getPrintUnqual session
 	putStrLn (showSDocForUser unqual $
      		   vcat (intersperse (text "") $
-		   [ pprInfo exts stuff | Just stuff <-  mb_stuffs ]))
+		         map (pprInfo pefas) filtered))
 
   -- 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
--- ToDo!!
-	 | otherwise		           = False
-
-pprInfo exts (thing, fixity, insts)
-  =  pprTyThingInContextLoc exts thing 
+filterOutChildren :: (a -> TyThing) -> [a] -> [a]
+filterOutChildren get_thing xs 
+  = [x | x <- xs, not (getName (get_thing x) `elemNameSet` implicits)]
+  where
+    implicits = mkNameSet [getName t | x <- xs, t <- implicitTyThings (get_thing x)]
+
+pprInfo :: PrintExplicitForalls -> (TyThing, Fixity, [GHC.Instance]) -> SDoc
+pprInfo pefas (thing, fixity, insts)
+  =  pprTyThingInContextLoc pefas thing
   $$ show_fixity fixity
   $$ vcat (map GHC.pprInstance insts)
   where
@@ -629,8 +745,7 @@ pprInfo exts (thing, fixity, insts)
 runMain :: String -> GHCi ()
 runMain args = do
   let ss = concat $ intersperse "," (map (\ s -> ('"':s)++"\"") (toArgs args))
-  runCommand $ '[': ss ++ "] `System.Environment.withArgs` main"
-  return ()
+  enqueueCommands  ['[': ss ++ "] `System.Environment.withArgs` main"]
 
 addModule :: [FilePath] -> GHCi ()
 addModule files = do
@@ -656,25 +771,47 @@ changeDirectory dir = do
   io (setCurrentDirectory dir)
 
 editFile :: String -> GHCi ()
-editFile str
-  | null str  = do
-	-- find the name of the "topmost" file loaded
-     session <- getSession
-     graph0 <- io (GHC.getModuleGraph session)
-     graph1 <- filterM (io . GHC.isLoaded session . GHC.ms_mod_name) graph0
-     let graph2 = flattenSCCs (GHC.topSortModuleGraph True graph1 Nothing)
-     case GHC.ml_hs_file (GHC.ms_location (last graph2)) of
-	Just file -> do_edit file
-	Nothing   -> throwDyn (CmdLineError "unknown file name")
-  | otherwise = do_edit str
-  where
-	do_edit file = do
-	   st <- getGHCiState
-	   let cmd = editor st
-	   when (null cmd) $ 
-		throwDyn (CmdLineError "editor not set, use :set editor")
-	   io $ system (cmd ++ ' ':file)
-           return ()
+editFile str =
+  do file <- if null str then chooseEditFile else return str
+     st <- getGHCiState
+     let cmd = editor st
+     when (null cmd) 
+       $ throwDyn (CmdLineError "editor not set, use :set editor")
+     io $ system (cmd ++ ' ':file)
+     return ()
+
+-- The user didn't specify a file so we pick one for them.
+-- Our strategy is to pick the first module that failed to load,
+-- or otherwise the first target.
+--
+-- XXX: Can we figure out what happened if the depndecy analysis fails
+--      (e.g., because the porgrammeer mistyped the name of a module)?
+-- XXX: Can we figure out the location of an error to pass to the editor?
+-- XXX: if we could figure out the list of errors that occured during the
+-- last load/reaload, then we could start the editor focused on the first
+-- of those.
+chooseEditFile :: GHCi String
+chooseEditFile =
+  do session <- getSession
+     let hasFailed x = io $ fmap not $ GHC.isLoaded session $ GHC.ms_mod_name x
+
+     graph <- io (GHC.getModuleGraph session)
+     failed_graph <- filterM hasFailed graph
+     let order g  = flattenSCCs $ GHC.topSortModuleGraph True g Nothing
+         pick xs  = case xs of
+                      x : _ -> GHC.ml_hs_file (GHC.ms_location x)
+                      _     -> Nothing
+
+     case pick (order failed_graph) of
+       Just file -> return file
+       Nothing   -> 
+         do targets <- io (GHC.getTargets session)
+            case msum (map fromTarget targets) of
+              Just file -> return file
+              Nothing   -> throwDyn (CmdLineError "No files to edit.")
+          
+  where fromTarget (GHC.Target (GHC.TargetFile f _) _) = Just f
+        fromTarget _ = Nothing -- when would we get a module target?
 
 defineMacro :: String -> GHCi ()
 defineMacro s = do
@@ -703,7 +840,8 @@ defineMacro s = do
 runMacro :: GHC.HValue{-String -> IO String-} -> String -> GHCi Bool
 runMacro fun s = do
   str <- io ((unsafeCoerce# fun :: String -> IO String) s)
-  stringLoop (lines str)
+  enqueueCommands (lines str)
+  return False
 
 undefineMacro :: String -> GHCi ()
 undefineMacro macro_name = do
@@ -718,6 +856,17 @@ undefineMacro macro_name = do
 	else do
   io (writeIORef commands (filter ((/= macro_name) . cmdName) cmds))
 
+cmdCmd :: String -> GHCi ()
+cmdCmd str = do
+  let expr = '(' : str ++ ") :: IO String"
+  session <- getSession
+  maybe_hv <- io (GHC.compileExpr session expr)
+  case maybe_hv of
+    Nothing -> return ()
+    Just hv -> do 
+        cmds <- io $ (unsafeCoerce# hv :: IO String)
+        enqueueCommands (lines cmds)
+        return ()
 
 loadModule :: [(FilePath, Maybe Phase)] -> GHCi SuccessFlag
 loadModule fs = timeIt (loadModule' fs)
@@ -730,6 +879,7 @@ loadModule' files = do
   session <- getSession
 
   -- unload first
+  discardActiveBreakPoints
   io (GHC.setTargets session [])
   io (GHC.load session LoadAllTargets)
 
@@ -745,15 +895,13 @@ loadModule' files = do
   -- as a ToDo for now.
 
   io (GHC.setTargets session targets)
-  ok <- io (GHC.load session LoadAllTargets)
-  afterLoad ok session
-  return ok
+  doLoad session LoadAllTargets
 
 checkModule :: String -> GHCi ()
 checkModule m = do
   let modl = GHC.mkModuleName m
   session <- getSession
-  result <- io (GHC.checkModule session modl)
+  result <- io (GHC.checkModule session modl False)
   case result of
     Nothing -> io $ putStrLn "Nothing"
     Just r  -> io $ putStrLn (showSDoc (
@@ -768,26 +916,26 @@ checkModule m = do
   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.mkModuleName m)))
+  doLoad session $ if null m then LoadAllTargets 
+                             else LoadUpTo (GHC.mkModuleName m)
+  return ()
+
+doLoad session howmuch = do
+  -- turn off breakpoints before we load: we can't turn them off later, because
+  -- the ModBreaks will have gone away.
+  discardActiveBreakPoints
+  ok <- io (GHC.load session howmuch)
   afterLoad ok session
+  return ok
 
 afterLoad ok session = do
   io (revertCAFs)  -- always revert CAFs on load.
-  discardResumeContext
   discardTickArrays
-  discardActiveBreakPoints
-  graph <- io (GHC.getModuleGraph session)
-  graph' <- filterM (io . GHC.isLoaded session . GHC.ms_mod_name) graph
-  setContextAfterLoad session graph'
-  modulesLoadedMsg ok (map GHC.ms_mod_name graph')
+  loaded_mods <- getLoadedModules session
+  setContextAfterLoad session loaded_mods
+  modulesLoadedMsg ok (map GHC.ms_mod_name loaded_mods)
 
 setContextAfterLoad session [] = do
   prel_mod <- getPrelude
@@ -843,8 +991,10 @@ typeOfExpr str
        maybe_ty <- io (GHC.exprType cms str)
        case maybe_ty of
 	  Nothing -> return ()
-	  Just ty -> do ty' <- cleanType ty
-                        printForUser $ text str <> text " :: " <> ppr ty'
+	  Just ty -> do dflags <- getDynFlags
+		        let pefas = dopt Opt_PrintExplicitForalls dflags
+                        printForUser $ text str <+> dcolon
+					<+> pprTypeForUser pefas ty
 
 kindOfType :: String -> GHCi ()
 kindOfType str 
@@ -852,7 +1002,7 @@ kindOfType str
        maybe_ty <- io (GHC.typeKind cms str)
        case maybe_ty of
 	  Nothing    -> return ()
-	  Just ty    -> printForUser $ text str <> text " :: " <> ppr ty
+	  Just ty    -> printForUser $ text str <+> dcolon <+> ppr ty
           
 quit :: String -> GHCi Bool
 quit _ = return True
@@ -872,8 +1022,8 @@ browseCmd m =
 
 browseModule m exports_only = do
   s <- getSession
-  modl <- if exports_only then lookupModule s m
-                          else wantInterpretedModule s m
+  modl <- if exports_only then lookupModule m
+                          else wantInterpretedModule m
 
   -- Temporarily set the context to the module we're interested in,
   -- just so we can get an appropriate PrintUnqualified
@@ -890,16 +1040,16 @@ browseModule m exports_only = do
     Just mod_info -> do
         let names
 	       | exports_only = GHC.modInfoExports mod_info
-	       | otherwise    = fromMaybe [] (GHC.modInfoTopLevelScope mod_info)
+	       | otherwise    = GHC.modInfoTopLevelScope mod_info
+				`orElse` []
 
-	    filtered = filterOutChildren names
-	
-        things <- io $ mapM (GHC.lookupName s) filtered
+        mb_things <- io $ mapM (GHC.lookupName s) names
+ 	let filtered_things = filterOutChildren (\t -> t) (catMaybes mb_things)
 
         dflags <- getDynFlags
-	let exts = dopt Opt_GlasgowExts dflags
+	let pefas = dopt Opt_PrintExplicitForalls dflags
 	io (putStrLn (showSDocForUser unqual (
-		vcat (map (pprTyThingInContext exts) (catMaybes things))
+		vcat (map (pprTyThingInContext pefas) filtered_things)
 	   )))
 	-- ToDo: modInfoInstances currently throws an exception for
 	-- package modules.  When it works, we can do this:
@@ -1012,6 +1162,19 @@ setEditor cmd = do
   st <- getGHCiState
   setGHCiState st{ editor = cmd }
 
+setStop str@(c:_) | isDigit c
+  = do let (nm_str,rest) = break (not.isDigit) str
+           nm = read nm_str
+       st <- getGHCiState
+       let old_breaks = breaks st
+       if all ((/= nm) . fst) old_breaks
+              then printForUser (text "Breakpoint" <+> ppr nm <+>
+                                 text "does not exist")
+              else do
+       let new_breaks = map fn old_breaks
+           fn (i,loc) | i == nm   = (i,loc { onBreakCmd = dropWhile isSpace rest })
+                      | otherwise = (i,loc)
+       setGHCiState st{ breaks = new_breaks }
 setStop cmd = do
   st <- getGHCiState
   setGHCiState st{ stop = cmd }
@@ -1029,8 +1192,10 @@ 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
+      newDynFlags minus_opts
+
+newDynFlags minus_opts = do
       dflags <- getDynFlags
       let pkg_flags = packageFlags dflags
       (dflags',leftovers) <- io $ GHC.parseDynamicFlags dflags minus_opts
@@ -1068,10 +1233,11 @@ unsetOptions str
 
        mapM_ unsetOpt plus_opts
  
-       -- can't do GHC flags for now
-       if (not (null minus_opts))
-	  then throwDyn (CmdLineError "can't unset GHC command-line flags")
-	  else return ()
+       let no_flag ('-':'f':rest) = return ("-fno-" ++ rest)
+           no_flag f = throwDyn (ProgramError ("don't know how to reverse " ++ f))
+
+       no_flags <- mapM no_flag minus_opts
+       newDynFlags no_flags
 
 isMinus ('-':s) = True
 isMinus _ = False
@@ -1103,53 +1269,63 @@ optToStr RevertCAFs = "r"
 -- ---------------------------------------------------------------------------
 -- code for `:show'
 
-showCmd str =
+showCmd str = do
+  st <- getGHCiState
   case words str of
+        ["args"]     -> io $ putStrLn (show (args st))
+        ["prog"]     -> io $ putStrLn (show (progname st))
+        ["prompt"]   -> io $ putStrLn (show (prompt st))
+        ["editor"]   -> io $ putStrLn (show (editor st))
+        ["stop"]     -> io $ putStrLn (show (stop st))
 	["modules" ] -> showModules
 	["bindings"] -> showBindings
 	["linker"]   -> io showLinkerState
-        ["breaks"] -> showBkptTable
-        ["context"] -> showContext
-	_ -> throwDyn (CmdLineError "syntax:  :show [modules|bindings|breaks]")
+        ["breaks"]   -> showBkptTable
+        ["context"]  -> showContext
+	_ -> throwDyn (CmdLineError "syntax:  :show [args|prog|prompt|editor|stop|modules|bindings|breaks|context]")
 
 showModules = do
   session <- getSession
-  let show_one ms = do m <- io (GHC.showModule session ms)
-		       io (putStrLn m)
+  loaded_mods <- getLoadedModules session
+        -- we want *loaded* modules only, see #1734
+  let show_one ms = do m <- io (GHC.showModule session ms); io (putStrLn m)
+  mapM_ show_one loaded_mods
+
+getLoadedModules :: GHC.Session -> GHCi [GHC.ModSummary]
+getLoadedModules session = do
   graph <- io (GHC.getModuleGraph session)
-  mapM_ show_one graph
+  filterM (io . GHC.isLoaded session . GHC.ms_mod_name) graph
 
 showBindings = do
   s <- getSession
   unqual <- io (GHC.getPrintUnqual s)
   bindings <- io (GHC.getBindings s)
-  mapM_ showTyThing bindings
+  mapM_ printTyThing $ sortBy compareTyThings bindings
   return ()
 
-showTyThing (AnId id) = do 
-  ty' <- cleanType (GHC.idType id)
-  printForUser $ ppr id <> text " :: " <> ppr ty'
-showTyThing _  = return ()
+compareTyThings :: TyThing -> TyThing -> Ordering
+t1 `compareTyThings` t2 = getName t1 `compareNames` getName t2
 
--- 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
+printTyThing :: TyThing -> GHCi ()
+printTyThing tyth = do dflags <- getDynFlags
+                       let pefas = dopt Opt_PrintExplicitForalls dflags
+		       printForUser (pprTyThing pefas tyth)
 
 showBkptTable :: GHCi ()
 showBkptTable = do
-   activeBreaks <- getActiveBreakPoints 
-   printForUser $ ppr activeBreaks 
+  st <- getGHCiState
+  printForUser $ prettyLocations (breaks st)
 
 showContext :: GHCi ()
 showContext = do
-   st <- getGHCiState
-   printForUser $ vcat (map pp_resume (resume st))
+   session <- getSession
+   resumes <- io $ GHC.getResumeContext session
+   printForUser $ vcat (map pp_resume (reverse resumes))
   where
-   pp_resume (span, _, _) = ptext SLIT("Stopped at") <+> ppr span
+   pp_resume resume =
+        ptext SLIT("--> ") <> text (GHC.resumeStmt resume)
+        $$ nest 2 (ptext SLIT("Stopped at") <+> ppr (GHC.resumeSpan resume))
+
 
 -- -----------------------------------------------------------------------------
 -- Completion
@@ -1161,10 +1337,11 @@ completeNone w = return []
 completeWord :: String -> Int -> Int -> IO (Maybe (String, [String]))
 completeWord w start end = do
   line <- Readline.getLineBuffer
-  case w of 
+  let line_words = words (dropWhile isSpace line)
+  case w of
      ':':_ | all isSpace (take (start-1) line) -> wrapCompleter completeCmd w
      _other
-	| Just c <- is_cmd line -> do
+	| ((':':c) : _) <- line_words -> do
 	   maybe_cmd <- lookupCommand c
            let (n,w') = selectWord (words' 0 line)
 	   case maybe_cmd of
@@ -1173,6 +1350,8 @@ completeWord w start end = do
 	     Just (_,_,True,complete) -> let complete' w = do rets <- complete w
                                                               return (map (drop n) rets)
                                          in wrapCompleter complete' w'
+        | ("import" : _) <- line_words ->
+                wrapCompleter completeModule w
 	| otherwise     -> do
 		--printf "complete %s, start = %d, end = %d\n" w start end
 		wrapCompleter completeIdentifier w
@@ -1188,9 +1367,6 @@ completeWord w start end = do
               | offset+length x >= start = (start-offset,take (end-offset) x)
               | otherwise = selectWord xs
 
-is_cmd line 
- | ((':':w) : _) <- words (dropWhile isSpace line) = Just w
- | otherwise = Nothing
 
 completeCmd w = do
   cmds <- readIORef commands
@@ -1327,6 +1503,32 @@ expandPath path =
    other -> 
 	return other
 
+wantInterpretedModule :: String -> GHCi Module
+wantInterpretedModule str = do
+   session <- getSession
+   modl <- lookupModule str
+   is_interpreted <- io (GHC.moduleIsInterpreted session modl)
+   when (not is_interpreted) $
+       throwDyn (CmdLineError ("module '" ++ str ++ "' is not interpreted"))
+   return modl
+
+wantNameFromInterpretedModule noCanDo str and_then = do
+   session <- getSession
+   names <- io $ GHC.parseName session str
+   case names of
+      []    -> return ()
+      (n:_) -> do
+            let modl = GHC.nameModule n
+            if not (GHC.isExternalName n)
+               then noCanDo n $ ppr n <>
+                                text " is not defined in an interpreted module"
+               else do
+            is_interpreted <- io (GHC.moduleIsInterpreted session modl)
+            if not is_interpreted
+               then noCanDo n $ text "module " <> ppr modl <>
+                                text " is not interpreted"
+               else and_then n
+
 -- ----------------------------------------------------------------------------
 -- Windows console setup
 
@@ -1338,14 +1540,17 @@ setUpConsole = do
 	-- similarly for characters we write to the console.
 	--
 	-- At the moment, GHCi pretends all input is Latin-1.  In the
-	-- future we should support UTF-8, but for now we set the code pages
-	-- to Latin-1.
+	-- future we should support UTF-8, but for now we set the code
+	-- pages to Latin-1.  Doing it this way does lead to problems,
+	-- however: see bug #1649.
 	--
 	-- It seems you have to set the font in the console window to
 	-- a Unicode font in order for output to work properly,
 	-- otherwise non-ASCII characters are mapped wrongly.  sigh.
 	-- (see MSDN for SetConsoleOutputCP()).
 	--
+        -- This call has been known to hang on some machines, see bug #1483
+        --
 	setConsoleCP 28591       -- ISO Latin-1
 	setConsoleOutputCP 28591 -- ISO Latin-1
 #endif
@@ -1354,34 +1559,72 @@ setUpConsole = do
 -- -----------------------------------------------------------------------------
 -- commands for debugger
 
-foreign import ccall "rts_setStepFlag" setStepFlag :: IO () 
-
-stepCmd :: String -> GHCi Bool
-stepCmd [] = doContinue setStepFlag 
-stepCmd expression = do
-   io $ setStepFlag
-   runCommand expression
-
-continueCmd :: String -> GHCi Bool
-continueCmd [] = doContinue $ return () 
-continueCmd other = do
-   io $ putStrLn "The continue command accepts no arguments."
-   return False
-
-doContinue :: IO () -> GHCi Bool
-doContinue actionBeforeCont = do 
-   resumeAction <- popResume
-   case resumeAction of
-      Nothing -> do 
-         io $ putStrLn "There is no computation running."
-         return False
-      Just (_,_,handle) -> do
-         io $ actionBeforeCont
-         session <- getSession
-         runResult <- io $ GHC.resume session handle
-         names <- switchOnRunResult runResult
-         finishEvalExpr names
-         return False
+sprintCmd = pprintCommand False False
+printCmd  = pprintCommand True False
+forceCmd  = pprintCommand False True
+
+pprintCommand bind force str = do
+  session <- getSession
+  io $ pprintClosureCommand session bind force str
+
+stepCmd :: String -> GHCi ()
+stepCmd []         = doContinue (const True) GHC.SingleStep
+stepCmd expression = do runStmt expression GHC.SingleStep; return ()
+
+stepLocalCmd :: String -> GHCi ()
+stepLocalCmd  [] = do 
+  mb_span <- getCurrentBreakSpan
+  case mb_span of
+    Nothing  -> stepCmd []
+    Just loc -> do
+       Just mod <- getCurrentBreakModule
+       current_toplevel_decl <- enclosingTickSpan mod loc
+       doContinue (`isSubspanOf` current_toplevel_decl) GHC.SingleStep
+
+stepLocalCmd expression = stepCmd expression
+
+stepModuleCmd :: String -> GHCi ()
+stepModuleCmd  [] = do 
+  mb_span <- getCurrentBreakSpan
+  case mb_span of
+    Nothing  -> stepCmd []
+    Just loc -> do
+       Just span <- getCurrentBreakSpan
+       let f some_span = optSrcSpanFileName span == optSrcSpanFileName some_span
+       doContinue f GHC.SingleStep
+
+stepModuleCmd expression = stepCmd expression
+
+-- | Returns the span of the largest tick containing the srcspan given
+enclosingTickSpan :: Module -> SrcSpan -> GHCi SrcSpan
+enclosingTickSpan mod src = do
+  ticks <- getTickArray mod
+  let line = srcSpanStartLine src
+  ASSERT (inRange (bounds ticks) line) do
+  let enclosing_spans = [ span | (_,span) <- ticks ! line
+                               , srcSpanEnd span >= srcSpanEnd src]
+  return . head . sortBy leftmost_largest $ enclosing_spans
+
+traceCmd :: String -> GHCi ()
+traceCmd []         = doContinue (const True) GHC.RunAndLogSteps
+traceCmd expression = do runStmt expression GHC.RunAndLogSteps; return ()
+
+continueCmd :: String -> GHCi ()
+continueCmd = noArgs $ doContinue (const True) GHC.RunToCompletion
+
+-- doContinue :: SingleStep -> GHCi ()
+doContinue pred step = do 
+  session <- getSession
+  runResult <- io $ GHC.resume session step
+  afterRunStmt pred runResult
+  return ()
+
+abandonCmd :: String -> GHCi ()
+abandonCmd = noArgs $ do
+  s <- getSession
+  b <- io $ GHC.abandon s -- the prompt will change to indicate the new context
+  when (not b) $ io $ putStrLn "There is no computation running."
+  return ()
 
 deleteCmd :: String -> GHCi ()
 deleteCmd argLine = do
@@ -1400,6 +1643,55 @@ deleteCmd argLine = do
          | all isDigit str = deleteBreak (read str)
          | otherwise = return ()
 
+historyCmd :: String -> GHCi ()
+historyCmd arg
+  | null arg        = history 20
+  | all isDigit arg = history (read arg)
+  | otherwise       = io $ putStrLn "Syntax:  :history [num]"
+  where
+  history num = do
+    s <- getSession
+    resumes <- io $ GHC.getResumeContext s
+    case resumes of
+      [] -> io $ putStrLn "Not stopped at a breakpoint"
+      (r:rs) -> do
+        let hist = GHC.resumeHistory r
+            (took,rest) = splitAt num hist
+        spans <- mapM (io . GHC.getHistorySpan s) took
+        let nums  = map (printf "-%-3d:") [(1::Int)..]
+        let names = map GHC.historyEnclosingDecl took
+        printForUser (vcat(zipWith3 
+                             (\x y z -> x <+> y <+> z) 
+                             (map text nums) 
+                             (map (bold . ppr) names)
+                             (map (parens . ppr) spans)))
+        io $ putStrLn $ if null rest then "<end of history>" else "..."
+
+bold c | do_bold   = text start_bold <> c <> text end_bold
+       | otherwise = c
+
+backCmd :: String -> GHCi ()
+backCmd = noArgs $ do
+  s <- getSession
+  (names, ix, span) <- io $ GHC.back s
+  printForUser $ ptext SLIT("Logged breakpoint at") <+> ppr span
+  printTypeOfNames s names
+   -- run the command set with ":set stop <cmd>"
+  st <- getGHCiState
+  enqueueCommands [stop st]
+
+forwardCmd :: String -> GHCi ()
+forwardCmd = noArgs $ do
+  s <- getSession
+  (names, ix, span) <- io $ GHC.forward s
+  printForUser $ (if (ix == 0)
+                    then ptext SLIT("Stopped at")
+                    else ptext SLIT("Logged breakpoint at")) <+> ppr span
+  printTypeOfNames s names
+   -- run the command set with ":set stop <cmd>"
+  st <- getGHCiState
+  enqueueCommands [stop st]
+
 -- handle the "break" command
 breakCmd :: String -> GHCi ()
 breakCmd argLine = do
@@ -1411,7 +1703,7 @@ breakSwitch _session [] = do
    io $ putStrLn "The break command requires at least one argument."
 breakSwitch session args@(arg1:rest) 
    | looksLikeModuleName arg1 = do
-        mod <- wantInterpretedModule session arg1
+        mod <- wantInterpretedModule arg1
         breakByModule session mod rest
    | all isDigit arg1 = do
         (toplevel, _) <- io $ GHC.getContext session 
@@ -1420,49 +1712,34 @@ breakSwitch session args@(arg1:rest)
            [] -> do 
               io $ putStrLn "Cannot find default module for breakpoint." 
               io $ putStrLn "Perhaps no modules are loaded for debugging?"
-   | otherwise = do -- assume it's a name
-        names <- io $ GHC.parseName session arg1
-        case names of
-          []    -> return ()
-          (n:_) -> do
-            let loc  = GHC.nameSrcLoc n
-                modl = GHC.nameModule n
-            is_interpreted <- io (GHC.moduleIsInterpreted session modl)
-            if not is_interpreted
-               then noCanDo $ text "module " <> ppr modl <>
-                              text " is not interpreted"
-               else do
-            if GHC.isGoodSrcLoc loc
-               then findBreakAndSet (GHC.nameModule n) $ 
-                         findBreakByCoord (GHC.srcLocLine loc, 
+   | otherwise = do -- try parsing it as an identifier
+        wantNameFromInterpretedModule noCanDo arg1 $ \name -> do
+        let loc = GHC.srcSpanStart (GHC.nameSrcSpan name)
+        if GHC.isGoodSrcLoc loc
+               then findBreakAndSet (GHC.nameModule name) $ 
+                         findBreakByCoord (Just (GHC.srcLocFile loc))
+                                          (GHC.srcLocLine loc, 
                                            GHC.srcLocCol loc)
-               else noCanDo $ text "can't find its location: " <>
-                              ppr loc
-           where
-             noCanDo why = printForUser $
+               else noCanDo name $ text "can't find its location: " <> ppr loc
+       where
+          noCanDo n why = printForUser $
                 text "cannot set breakpoint on " <> ppr n <> text ": " <> why
 
-
-wantInterpretedModule :: Session -> String -> GHCi Module
-wantInterpretedModule session str = do
-   modl <- io $ GHC.findModule session (GHC.mkModuleName str) Nothing
-   is_interpreted <- io (GHC.moduleIsInterpreted session modl)
-   when (not is_interpreted) $
-       throwDyn (CmdLineError ("module '" ++ str ++ "' is not interpreted"))
-   return modl
-
 breakByModule :: Session -> Module -> [String] -> GHCi () 
 breakByModule session mod args@(arg1:rest)
    | all isDigit arg1 = do  -- looks like a line number
         breakByModuleLine mod (read arg1) rest
-   | otherwise = io $ putStrLn "Invalid arguments to :break"
+breakByModule session mod _
+   = breakSyntax
 
 breakByModuleLine :: Module -> Int -> [String] -> GHCi ()
 breakByModuleLine mod line args
    | [] <- args = findBreakAndSet mod $ findBreakByLine line
    | [col] <- args, all isDigit col =
-        findBreakAndSet mod $ findBreakByCoord (line, read col)
-   | otherwise = io $ putStrLn "Invalid arguments to :break"
+        findBreakAndSet mod $ findBreakByCoord Nothing (line, read col)
+   | otherwise = breakSyntax
+
+breakSyntax = throwDyn (CmdLineError "Syntax: :break [<mod>] <line> [<column>]")
 
 findBreakAndSet :: Module -> (TickArray -> Maybe (Int, SrcSpan)) -> GHCi ()
 findBreakAndSet mod lookupTickTree = do 
@@ -1480,6 +1757,7 @@ findBreakAndSet mod lookupTickTree = do
                              { breakModule = mod
                              , breakLoc = span
                              , breakTick = tick
+                             , onBreakCmd = ""
                              }
                printForUser $
                   text "Breakpoint " <> ppr nm <>
@@ -1500,9 +1778,9 @@ findBreakByLine :: Int -> TickArray -> Maybe (BreakIndex,SrcSpan)
 findBreakByLine line arr
   | not (inRange (bounds arr) line) = Nothing
   | otherwise =
-    listToMaybe (sortBy leftmost_largest  complete)   `mplus`
-    listToMaybe (sortBy leftmost_smallest incomplete) `mplus`
-    listToMaybe (sortBy rightmost ticks)
+    listToMaybe (sortBy (leftmost_largest `on` snd)  complete)   `mplus`
+    listToMaybe (sortBy (leftmost_smallest `on` snd) incomplete) `mplus`
+    listToMaybe (sortBy (rightmost `on` snd) ticks)
   where 
         ticks = arr ! line
 
@@ -1512,36 +1790,93 @@ findBreakByLine line arr
         (complete,incomplete) = partition ends_here starts_here
             where ends_here (nm,span) = GHC.srcSpanEndLine span == line
 
-findBreakByCoord :: (Int,Int) -> TickArray -> Maybe (BreakIndex,SrcSpan)
-findBreakByCoord (line, col) arr
+findBreakByCoord :: Maybe FastString -> (Int,Int) -> TickArray
+                 -> Maybe (BreakIndex,SrcSpan)
+findBreakByCoord mb_file (line, col) arr
   | not (inRange (bounds arr) line) = Nothing
   | otherwise =
-    listToMaybe (sortBy rightmost contains)
+    listToMaybe (sortBy (rightmost `on` snd) contains ++
+                 sortBy (leftmost_smallest `on` snd) after_here)
   where 
         ticks = arr ! line
 
         -- the ticks that span this coordinate
-        contains = [ tick | tick@(nm,span) <- ticks, span `spans` (line,col) ]
-
-leftmost_smallest  (_,a) (_,b) = a `compare` b
-leftmost_largest   (_,a) (_,b) = (GHC.srcSpanStart a `compare` GHC.srcSpanStart b)
-                                `thenCmp`
-                                 (GHC.srcSpanEnd b `compare` GHC.srcSpanEnd a)
-rightmost (_,a) (_,b) = b `compare` a
-
-spans :: SrcSpan -> (Int,Int) -> Bool
-spans span (l,c) = GHC.srcSpanStart span <= loc && loc <= GHC.srcSpanEnd span
-   where loc = GHC.mkSrcLoc (GHC.srcSpanFile span) l c
-
-start_bold = BS.pack "\ESC[1m"
-end_bold   = BS.pack "\ESC[0m"
+        contains = [ tick | tick@(nm,span) <- ticks, span `spans` (line,col),
+                            is_correct_file span ]
+
+        is_correct_file span
+                 | Just f <- mb_file = GHC.srcSpanFile span == f
+                 | otherwise         = True
+
+        after_here = [ tick | tick@(nm,span) <- ticks,
+                              GHC.srcSpanStartLine span == line,
+                              GHC.srcSpanStartCol span >= col ]
+
+-- For now, use ANSI bold on terminals that we know support it.
+-- Otherwise, we add a line of carets under the active expression instead.
+-- In particular, on Windows and when running the testsuite (which sets
+-- TERM to vt100 for other reasons) we get carets.
+-- We really ought to use a proper termcap/terminfo library.
+do_bold :: Bool
+do_bold = (`isPrefixOf` unsafePerformIO mTerm) `any` ["xterm", "linux"]
+    where mTerm = System.Environment.getEnv "TERM"
+                  `Exception.catch` \e -> return "TERM not set"
+
+start_bold :: String
+start_bold = "\ESC[1m"
+end_bold :: String
+end_bold   = "\ESC[0m"
 
 listCmd :: String -> GHCi ()
-listCmd str = do
-   st <- getGHCiState
-   case resume st of
-      []  -> printForUser $ text "not stopped at a breakpoint; nothing to list"
-      (span,_,_):_ -> io $ listAround span True
+listCmd "" = do
+   mb_span <- getCurrentBreakSpan
+   case mb_span of
+      Nothing  -> printForUser $ text "not stopped at a breakpoint; nothing to list"
+      Just span | GHC.isGoodSrcSpan span -> io $ listAround span True
+                | otherwise              -> printForUser $ text "unable to list source for" <+> ppr span
+listCmd str = list2 (words str)
+
+list2 [arg] | all isDigit arg = do
+    session <- getSession
+    (toplevel, _) <- io $ GHC.getContext session 
+    case toplevel of
+        [] -> io $ putStrLn "No module to list"
+        (mod : _) -> listModuleLine mod (read arg)
+list2 [arg1,arg2] | looksLikeModuleName arg1, all isDigit arg2 = do
+        mod <- wantInterpretedModule arg1
+        listModuleLine mod (read arg2)
+list2 [arg] = do
+        wantNameFromInterpretedModule noCanDo arg $ \name -> do
+        let loc = GHC.srcSpanStart (GHC.nameSrcSpan name)
+        if GHC.isGoodSrcLoc loc
+               then do
+                  tickArray <- getTickArray (GHC.nameModule name)
+                  let mb_span = findBreakByCoord (Just (GHC.srcLocFile loc))
+                                        (GHC.srcLocLine loc, GHC.srcLocCol loc)
+                                        tickArray
+                  case mb_span of
+                    Nothing       -> io $ listAround (GHC.srcLocSpan loc) False
+                    Just (_,span) -> io $ listAround span False
+               else
+                  noCanDo name $ text "can't find its location: " <>
+                                 ppr loc
+    where
+        noCanDo n why = printForUser $
+            text "cannot list source code for " <> ppr n <> text ": " <> why
+list2  _other = 
+        io $ putStrLn "syntax:  :list [<line> | <module> <line> | <identifier>]"
+
+listModuleLine :: Module -> Int -> GHCi ()
+listModuleLine modl line = do
+   session <- getSession
+   graph <- io (GHC.getModuleGraph session)
+   let this = filter ((== modl) . GHC.ms_mod) graph
+   case this of
+     [] -> panic "listModuleLine"
+     summ:_ -> do
+           let filename = fromJust (ml_hs_file (GHC.ms_location summ))
+               loc = GHC.mkSrcLoc (mkFastString (filename)) line 0
+           io $ listAround (GHC.srcLocSpan loc) False
 
 -- | list a section of a source file around a particular SrcSpan.
 -- If the highlight flag is True, also highlight the span using
@@ -1556,10 +1891,10 @@ listAround span do_highlight = do
           line_nos = [ fst_line .. ]
 
           highlighted | do_highlight = zipWith highlight line_nos these_lines
-                      | otherwise   = these_lines
+                      | otherwise    = [\p -> BS.concat[p,l] | l <- these_lines]
 
           bs_line_nos = [ BS.pack (show l ++ "  ") | l <- line_nos ]
-          prefixed = zipWith BS.append bs_line_nos highlighted
+          prefixed = zipWith ($) highlighted bs_line_nos
       --
       BS.putStrLn (BS.join (BS.pack "\n") prefixed)
   where
@@ -1573,19 +1908,37 @@ listAround span do_highlight = do
                    | otherwise  = 1
         pad_after = 1
 
-        highlight no line
+        highlight | do_bold   = highlight_bold
+                  | otherwise = highlight_carets
+
+        highlight_bold no line prefix
           | no == line1 && no == line2
           = let (a,r) = BS.splitAt col1 line
                 (b,c) = BS.splitAt (col2-col1) r
             in
-            BS.concat [a,start_bold,b,end_bold,c]
+            BS.concat [prefix, a,BS.pack start_bold,b,BS.pack end_bold,c]
           | no == line1
           = let (a,b) = BS.splitAt col1 line in
-            BS.concat [a, start_bold, b]
+            BS.concat [prefix, a, BS.pack start_bold, b]
           | no == line2
           = let (a,b) = BS.splitAt col2 line in
-            BS.concat [a, end_bold, b]
-          | otherwise   = line
+            BS.concat [prefix, a, BS.pack end_bold, b]
+          | otherwise   = BS.concat [prefix, line]
+
+        highlight_carets no line prefix
+          | no == line1 && no == line2
+          = BS.concat [prefix, line, nl, indent, BS.replicate col1 ' ',
+                                         BS.replicate (col2-col1) '^']
+          | no == line1
+          = BS.concat [indent, BS.replicate (col1 - 2) ' ', BS.pack "vv", nl, 
+                                         prefix, line]
+          | no == line2
+          = BS.concat [prefix, line, nl, indent, BS.replicate col2 ' ',
+                                         BS.pack "^^"]
+          | otherwise   = BS.concat [prefix, line]
+         where
+           indent = BS.pack ("  " ++ replicate (length (show no)) ' ')
+           nl = BS.singleton '\n'
 
 -- --------------------------------------------------------------------------
 -- Tick arrays
@@ -1613,10 +1966,38 @@ mkTickArray ticks
         [ (line, (nm,span)) | (nm,span) <- ticks,
                               line <- srcSpanLines span ]
     where
-        max_line = maximum (map GHC.srcSpanEndLine (map snd ticks))
+        max_line = foldr max 0 (map GHC.srcSpanEndLine (map snd ticks))
         srcSpanLines span = [ GHC.srcSpanStartLine span .. 
                               GHC.srcSpanEndLine span ]
 
+lookupModule :: String -> GHCi Module
+lookupModule modName
+   = do session <- getSession 
+        io (GHC.findModule session (GHC.mkModuleName modName) Nothing)
+
+-- don't reset the counter back to zero?
+discardActiveBreakPoints :: GHCi ()
+discardActiveBreakPoints = do
+   st <- getGHCiState
+   mapM (turnOffBreak.snd) (breaks st)
+   setGHCiState $ st { breaks = [] }
+
+deleteBreak :: Int -> GHCi ()
+deleteBreak identity = do
+   st <- getGHCiState
+   let oldLocations    = breaks st
+       (this,rest)     = partition (\loc -> fst loc == identity) oldLocations
+   if null this 
+      then printForUser (text "Breakpoint" <+> ppr identity <+>
+                         text "does not exist")
+      else do
+           mapM (turnOffBreak.snd) this
+           setGHCiState $ st { breaks = rest }
+
+turnOffBreak loc = do
+  (arr, _) <- getModBreak (breakModule loc)
+  io $ setBreakFlag False arr (breakTick loc)
+
 getModBreak :: Module -> GHCi (GHC.BreakArray, Array Int SrcSpan)
 getModBreak mod = do
    session <- getSession
@@ -1626,28 +2007,8 @@ getModBreak mod = do
    let ticks      = GHC.modBreaks_locs  modBreaks
    return (array, ticks)
 
-lookupModule :: Session -> String -> GHCi Module
-lookupModule session modName
-   = io (GHC.findModule session (GHC.mkModuleName modName) Nothing)
-
 setBreakFlag :: Bool -> GHC.BreakArray -> Int -> IO Bool 
 setBreakFlag toggle array index
    | toggle    = GHC.setBreakOn array index 
    | otherwise = GHC.setBreakOff array index
 
-
-{- these should probably go to the GHC API at some point -}
-enableBreakPoint  :: Session -> Module -> Int -> IO ()
-enableBreakPoint session mod index = return ()
-
-disableBreakPoint :: Session -> Module -> Int -> IO ()
-disableBreakPoint session mod index = return ()
-
-activeBreakPoints :: Session -> IO [(Module,Int)]
-activeBreakPoints session = return []
-
-enableSingleStep  :: Session -> IO ()
-enableSingleStep session = return ()
-
-disableSingleStep :: Session -> IO ()
-disableSingleStep session = return ()