import Control.Exception as Exception
-- import Control.Concurrent
+import System.FilePath
import qualified Data.ByteString.Char8 as BS
import Data.List
import Data.Maybe
import Control.Monad as Monad
import Text.Printf
import Foreign
-import Foreign.C ( withCStringLen )
+import Foreign.C
import GHC.Exts ( unsafeCoerce# )
import GHC.IOBase ( IOErrorType(InvalidArgument) )
+import GHC.TopHandler
import Data.IORef ( IORef, readIORef, writeIORef )
("print", keepGoing printCmd, Nothing, completeIdentifier),
("quit", quit, Nothing, completeNone),
("reload", keepGoing reloadModule, Nothing, completeNone),
+ ("run", keepGoing runRun, Nothing, completeIdentifier),
("set", keepGoing setCmd, Just flagWordBreakChars, completeSetOptions),
("show", keepGoing showCmd, Nothing, completeNone),
("sprint", keepGoing sprintCmd, Nothing, completeIdentifier),
--
-- NOTE: in order for us to override the default correctly, any custom entry
-- must be a SUBSET of word_break_chars.
-word_break_chars, flagWordBreakChars, filenameWordBreakChars :: String
+#ifdef USE_READLINE
+word_break_chars :: String
word_break_chars = let symbols = "!#$%&*+/<=>?@\\^|-~"
specials = "(),;[]`{}"
spaces = " \t\n"
in spaces ++ specials ++ symbols
+#endif
+
+flagWordBreakChars, filenameWordBreakChars :: String
flagWordBreakChars = " \t\n"
filenameWordBreakChars = " \t\n\\`@$><=;|&{(" -- bash defaults
keepGoing a str = a str >> return False
keepGoingPaths :: ([FilePath] -> GHCi ()) -> (String -> GHCi Bool)
-keepGoingPaths a str = a (toArgs str) >> return False
+keepGoingPaths a str
+ = do case toArgs str of
+ Left err -> io (hPutStrLn stderr err)
+ Right args -> a args
+ return False
shortHelpText :: String
shortHelpText = "use :? for help.\n"
" :module [+/-] [*]<mod> ... set the context for expression evaluation\n" ++
" :quit exit GHCi\n" ++
" :reload reload the current module set\n" ++
+ " :run function [<arguments> ...] run the function with the given arguments\n" ++
" :type <expr> show the type of <expr>\n" ++
" :undef <cmd> undefine user-defined command :<cmd>\n" ++
" :!<command> run the shell command <command>\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" ++
+ " :history [<n>] after :trace, show the execution history\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"++
+ " :steplocal single-step within the current top-level binding\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"++
+ " :trace <expr> evaluate <expr> with tracing on (see :history)\n"++
"\n" ++
" -- Commands for changing settings:\n" ++
" :show modules show the currently loaded modules\n" ++
" :show packages show the currently active package flags\n" ++
" :show languages show the currently active language flags\n" ++
- " :show <setting> show anything that can be set with :set (e.g. args)\n" ++
+ " :show <setting> show value of <setting>, which is one of\n" ++
+ " [args, prog, prompt, editor, stop]\n" ++
"\n"
findEditor :: IO String
return ""
#endif
-interactiveUI :: Session -> [(FilePath, Maybe Phase)] -> Maybe String -> IO ()
-interactiveUI session srcs maybe_expr = do
+interactiveUI :: Session -> [(FilePath, Maybe Phase)] -> Maybe [String]
+ -> IO ()
+interactiveUI session srcs maybe_exprs = do
-- HACK! If we happen to get into an infinite loop (eg the user
-- types 'let x=x in x' at the prompt), then the thread will block
-- on a blackhole, and become unreachable during GC. The GC will
-- Initialise buffering for the *interpreted* I/O system
initInterpBuffering session
- when (isNothing maybe_expr) $ do
+ when (isNothing maybe_exprs) $ do
-- Only for GHCi (not runghc and ghc -e):
-- Turn buffering off for the compiled program's stdout/stderr
hSetBuffering stdin NoBuffering
#ifdef USE_READLINE
- Readline.initialize
- Readline.setAttemptedCompletionFunction (Just completeWord)
- --Readline.parseAndBind "set show-all-if-ambiguous 1"
-
- Readline.setBasicWordBreakCharacters word_break_chars
- Readline.setCompleterWordBreakCharacters word_break_chars
- Readline.setCompletionAppendCharacter Nothing
+ is_tty <- hIsTerminalDevice stdin
+ when is_tty $ do
+ Readline.initialize
+ Readline.setAttemptedCompletionFunction (Just completeWord)
+ --Readline.parseAndBind "set show-all-if-ambiguous 1"
+
+ Readline.setBasicWordBreakCharacters word_break_chars
+ Readline.setCompleterWordBreakCharacters word_break_chars
+ Readline.setCompletionAppendCharacter Nothing
#endif
-- initial context is just the Prelude
default_editor <- findEditor
- startGHCi (runGHCi srcs maybe_expr)
+ startGHCi (runGHCi srcs maybe_exprs)
GHCiState{ progname = "<interactive>",
args = [],
prompt = "%s> ",
tickarrays = emptyModuleEnv,
last_command = Nothing,
cmdqueue = [],
- remembered_ctx = Nothing
+ remembered_ctx = []
}
#ifdef USE_READLINE
return ()
-runGHCi :: [(FilePath, Maybe Phase)] -> Maybe String -> GHCi ()
-runGHCi paths maybe_expr = do
- let read_dot_files = not opt_IgnoreDotGhci
+runGHCi :: [(FilePath, Maybe Phase)] -> Maybe [String] -> GHCi ()
+runGHCi paths maybe_exprs = do
+ let
+ read_dot_files = not opt_IgnoreDotGhci
- when (read_dot_files) $ do
- -- Read in ./.ghci.
- let file = "./.ghci"
- exists <- io (doesFileExist file)
- when exists $ do
- dir_ok <- io (checkPerms ".")
- file_ok <- io (checkPerms file)
+ current_dir = return (Just ".ghci")
+
+ app_user_dir = do
+ either_dir <- io $ IO.try (getAppUserDataDirectory "ghc")
+ case either_dir of
+ Right dir -> return (Just (dir </> "ghci.conf"))
+ _ -> return Nothing
+
+ home_dir = do
+ either_dir <- io $ IO.try (getEnv "HOME")
+ case either_dir of
+ Right home -> return (Just (home </> ".ghci"))
+ _ -> return Nothing
+
+ sourceConfigFile :: FilePath -> GHCi ()
+ sourceConfigFile file = do
+ exists <- io $ doesFileExist file
+ when exists $ do
+ dir_ok <- io $ checkPerms (getDirectory file)
+ file_ok <- io $ checkPerms file
when (dir_ok && file_ok) $ do
- either_hdl <- io (IO.try (openFile "./.ghci" ReadMode))
- case either_hdl of
- Left _e -> return ()
- Right hdl -> runCommands (fileLoop hdl False False)
+ either_hdl <- io $ IO.try (openFile file ReadMode)
+ case either_hdl of
+ Left _e -> return ()
+ Right hdl -> runCommands (fileLoop hdl False False)
+ where
+ getDirectory f = case takeDirectory f of "" -> "."; d -> d
when (read_dot_files) $ do
- -- Read in $HOME/.ghci
- either_dir <- io (IO.try getHomeDirectory)
- case either_dir of
- Left _e -> return ()
- Right dir -> do
- cwd <- io (getCurrentDirectory)
- when (dir /= cwd) $ do
- let file = dir ++ "/.ghci"
- ok <- io (checkPerms file)
- when ok $ do
- either_hdl <- io (IO.try (openFile file ReadMode))
- case either_hdl of
- Left _e -> return ()
- Right hdl -> runCommands (fileLoop hdl False False)
+ cfgs0 <- sequence [ current_dir, app_user_dir, home_dir ]
+ cfgs <- io $ mapM canonicalizePath (catMaybes cfgs0)
+ mapM_ sourceConfigFile (nub cfgs)
+ -- nub, because we don't want to read .ghci twice if the
+ -- CWD is $HOME.
-- Perform a :load for files given on the GHCi command line
-- When in -e mode, if the load fails then we want to stop
when (not (null paths)) $ do
ok <- ghciHandle (\e -> do showException e; return Failed) $
loadModule paths
- when (isJust maybe_expr && failed ok) $
+ when (isJust maybe_exprs && failed ok) $
io (exitWith (ExitFailure 1))
-- if verbosity is greater than 0, or we are connected to a
dflags <- getDynFlags
let show_prompt = verbosity dflags > 0 || is_tty
- case maybe_expr of
+ case maybe_exprs of
Nothing ->
do
#if defined(mingw32_HOST_OS)
#endif
-- enter the interactive loop
interactiveLoop is_tty show_prompt
- Just expr -> do
+ Just exprs -> do
-- just evaluate the expression we were given
- runCommandEval expr
- return ()
+ enqueueCommands exprs
+ let handle e = do st <- getGHCiState
+ -- Jump through some hoops to get the
+ -- current progname in the exception text:
+ -- <progname>: <exception>
+ io $ withProgName (progname st)
+ -- The "fast exit" part just calls exit()
+ -- directly instead of doing an orderly
+ -- runtime shutdown, otherwise the main
+ -- GHCi thread will complain about being
+ -- interrupted.
+ $ topHandlerFastExit e
+ runCommands' handle (return Nothing)
-- and finally, exit
io $ do when (verbosity dflags > 0) $ putStrLn "Leaving GHCi."
-
interactiveLoop :: Bool -> Bool -> GHCi ()
interactiveLoop is_tty show_prompt =
-- Ignore ^C exceptions caught here
return (Just c)
runCommands :: GHCi (Maybe String) -> GHCi ()
-runCommands getCmd = do
+runCommands = runCommands' handler
+
+runCommands' :: (Exception -> GHCi Bool) -- Exception handler
+ -> GHCi (Maybe String) -> GHCi ()
+runCommands' eh getCmd = do
mb_cmd <- noSpace queryQueue
mb_cmd <- maybe (noSpace getCmd) (return . Just) mb_cmd
case mb_cmd of
Nothing -> return ()
Just c -> do
- b <- ghciHandle handler (doCommand c)
- if b then return () else runCommands getCmd
+ b <- ghciHandle eh (doCommand c)
+ if b then return () else runCommands' eh getCmd
where
noSpace q = q >>= maybe (return Nothing)
(\c->case removeSpaces c of
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
--- exits, rather than printing out the exception.
-runCommandEval :: String -> GHCi Bool
-runCommandEval c = ghciHandle handleEval (doCommand c)
- where
- handleEval (ExitException code) = io (exitWith code)
- handleEval e = do handler e
- io (exitWith (ExitFailure 1))
-
- doCommand (':' : command) = specialCommand command
- doCommand stmt
- = 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.
- _ -> return True
-
runStmt :: String -> SingleStep -> GHCi Bool
runStmt stmt step
| null (filter (not.isSpace) stmt) = return False
| otherwise = ppr fix <+> ppr (GHC.getName thing)
runMain :: String -> GHCi ()
-runMain args = do
- let ss = concat $ intersperse "," (map (\ s -> ('"':s)++"\"") (toArgs args))
- enqueueCommands ['[': ss ++ "] `System.Environment.withArgs` main"]
+runMain s = case toArgs s of
+ Left err -> io (hPutStrLn stderr err)
+ Right args ->
+ do dflags <- getDynFlags
+ case mainFunIs dflags of
+ Nothing -> doWithArgs args "main"
+ Just f -> doWithArgs args f
+
+runRun :: String -> GHCi ()
+runRun s = case toCmdArgs s of
+ Left err -> io (hPutStrLn stderr err)
+ Right (cmd, args) -> doWithArgs args cmd
+
+doWithArgs :: [String] -> String -> GHCi ()
+doWithArgs args cmd = enqueueCommands ["System.Environment.withArgs " ++
+ show args ++ " (" ++ cmd ++ ")"]
addModule :: [FilePath] -> GHCi ()
addModule files = do
prev_context <- io $ GHC.getContext session
io (GHC.setTargets session [])
io (GHC.load session LoadAllTargets)
- setContextAfterLoad session prev_context []
+ setContextAfterLoad session prev_context False []
io (GHC.workingDirectoryChanged session)
dir <- expandPath dir
io (setCurrentDirectory dir)
loaded_mod_names = map GHC.moduleName loaded_mods
modulesLoadedMsg ok loaded_mod_names
- st <- getGHCiState
- if not retain_context
- then do
- setGHCiState st{ remembered_ctx = Nothing }
- setContextAfterLoad session prev_context loaded_mod_summaries
- else do
- -- figure out which modules we can keep in the context, which we
- -- have to put back, and which we have to remember because they
- -- are (temporarily) unavailable. See ghci.prog009, #1873, #1360
- let (as,bs) = prev_context
- as1 = filter isHomeModule as -- package modules are kept anyway
- bs1 = filter isHomeModule bs
- (as_ok, as_bad) = partition (`elem` loaded_mods) as1
- (bs_ok, bs_bad) = partition (`elem` loaded_mods) bs1
- (rem_as, rem_bs) = fromMaybe ([],[]) (remembered_ctx st)
- (rem_as_ok, rem_as_bad) = partition (`elem` loaded_mods) rem_as
- (rem_bs_ok, rem_bs_bad) = partition (`elem` loaded_mods) rem_bs
- as' = nub (as_ok++rem_as_ok)
- bs' = nub (bs_ok++rem_bs_ok)
- rem_as' = nub (rem_as_bad ++ as_bad)
- rem_bs' = nub (rem_bs_bad ++ bs_bad)
-
- -- Put back into the context any modules that we previously had
- -- to drop because they weren't available (rem_as_ok, rem_bs_ok).
- setContextKeepingPackageModules session prev_context (as',bs')
-
- -- If compilation failed, remember any modules that we are unable
- -- to load, so that we can put them back in the context in the future.
- case ok of
- Succeeded -> setGHCiState st{ remembered_ctx = Nothing }
- Failed -> setGHCiState st{ remembered_ctx = Just (rem_as',rem_bs') }
-
-
-
-setContextAfterLoad :: Session -> ([Module],[Module]) -> [GHC.ModSummary] -> GHCi ()
-setContextAfterLoad session prev [] = do
+ setContextAfterLoad session prev_context retain_context loaded_mod_summaries
+
+
+setContextAfterLoad :: Session -> ([Module],[Module]) -> Bool -> [GHC.ModSummary] -> GHCi ()
+setContextAfterLoad session prev keep_ctxt [] = do
prel_mod <- getPrelude
- setContextKeepingPackageModules session prev ([], [prel_mod])
-setContextAfterLoad session prev ms = do
+ setContextKeepingPackageModules session prev keep_ctxt ([], [prel_mod])
+setContextAfterLoad session prev keep_ctxt ms = do
-- load a target if one is available, otherwise load the topmost module.
targets <- io (GHC.getTargets session)
case [ m | Just m <- map (findTarget ms) targets ] of
load_this summary | m <- GHC.ms_mod summary = do
b <- io (GHC.moduleIsInterpreted session m)
- if b then setContextKeepingPackageModules session prev ([m], [])
+ if b then setContextKeepingPackageModules session prev keep_ctxt ([m], [])
else do
prel_mod <- getPrelude
- setContextKeepingPackageModules session prev ([],[prel_mod,m])
+ setContextKeepingPackageModules session prev keep_ctxt ([],[prel_mod,m])
-- | Keep any package modules (except Prelude) when changing the context.
setContextKeepingPackageModules
:: Session
-> ([Module],[Module]) -- previous context
+ -> Bool -- re-execute :module commands
-> ([Module],[Module]) -- new context
-> GHCi ()
-setContextKeepingPackageModules session prev_context (as,bs) = do
+setContextKeepingPackageModules session prev_context keep_ctxt (as,bs) = do
let (_,bs0) = prev_context
prel_mod <- getPrelude
let pkg_modules = filter (\p -> not (isHomeModule p) && p /= prel_mod) bs0
let bs1 = if null as then nub (prel_mod : bs) else bs
io $ GHC.setContext session as (nub (bs1 ++ pkg_modules))
+ if keep_ctxt
+ then do
+ st <- getGHCiState
+ mapM_ (playCtxtCmd False) (remembered_ctx st)
+ else do
+ st <- getGHCiState
+ setGHCiState st{ remembered_ctx = [] }
isHomeModule :: Module -> Bool
isHomeModule mod = GHC.modulePackageId mod == mainPackageId
setContext :: String -> GHCi ()
setContext str
- | all sensible mods = fn mods
+ | all sensible strs = do
+ playCtxtCmd True (cmd, as, bs)
+ st <- getGHCiState
+ setGHCiState st{ remembered_ctx = remembered_ctx st ++ [(cmd,as,bs)] }
| otherwise = throwDyn (CmdLineError "syntax: :module [+/-] [*]M1 ... [*]Mn")
where
- (fn, mods) = case str of
- '+':stuff -> (addToContext, words stuff)
- '-':stuff -> (removeFromContext, words stuff)
- stuff -> (newContext, words stuff)
+ (cmd, strs, as, bs) =
+ case str of
+ '+':stuff -> rest AddModules stuff
+ '-':stuff -> rest RemModules stuff
+ stuff -> rest SetContext stuff
+
+ rest cmd stuff = (cmd, strs, as, bs)
+ where strs = words stuff
+ (as,bs) = partitionWith starred strs
sensible ('*':m) = looksLikeModuleName m
sensible m = looksLikeModuleName m
-separate :: Session -> [String] -> [Module] -> [Module]
- -> GHCi ([Module],[Module])
-separate _ [] as bs = return (as,bs)
-separate session (('*':str):ms) as bs = do
- m <- wantInterpretedModule str
- separate session ms (m:as) bs
-separate session (str:ms) as bs = do
- m <- lookupModule str
- separate session ms as (m:bs)
-
-newContext :: [String] -> GHCi ()
-newContext strs = do
- s <- getSession
- (as,bs) <- separate s strs [] []
- prel_mod <- getPrelude
- let bs' = if null as && prel_mod `notElem` bs then prel_mod:bs else bs
- io $ GHC.setContext s as bs'
-
-
-addToContext :: [String] -> GHCi ()
-addToContext strs = do
- s <- getSession
- (as,bs) <- io $ GHC.getContext s
-
- (new_as,new_bs) <- separate s strs [] []
-
- let as_to_add = new_as \\ (as ++ bs)
- bs_to_add = new_bs \\ (as ++ bs)
-
- io $ GHC.setContext s (as ++ as_to_add) (bs ++ bs_to_add)
+ starred ('*':m) = Left m
+ starred m = Right m
-
-removeFromContext :: [String] -> GHCi ()
-removeFromContext strs = do
- s <- getSession
- (as,bs) <- io $ GHC.getContext s
-
- (as_to_remove,bs_to_remove) <- separate s strs [] []
-
- let as' = as \\ (as_to_remove ++ bs_to_remove)
- bs' = bs \\ (as_to_remove ++ bs_to_remove)
-
- io $ GHC.setContext s as' bs'
+playCtxtCmd :: Bool -> (CtxtCmd, [String], [String]) -> GHCi ()
+playCtxtCmd fail (cmd, as, bs)
+ = do
+ s <- getSession
+ (as',bs') <- do_checks fail
+ (prev_as,prev_bs) <- io $ GHC.getContext s
+ (new_as, new_bs) <-
+ case cmd of
+ SetContext -> do
+ prel_mod <- getPrelude
+ let bs'' = if null as && prel_mod `notElem` bs' then prel_mod:bs'
+ else bs'
+ return (as',bs'')
+ AddModules -> do
+ let as_to_add = as' \\ (prev_as ++ prev_bs)
+ bs_to_add = bs' \\ (prev_as ++ prev_bs)
+ return (prev_as ++ as_to_add, prev_bs ++ bs_to_add)
+ RemModules -> do
+ let new_as = prev_as \\ (as' ++ bs')
+ new_bs = prev_bs \\ (as' ++ bs')
+ return (new_as, new_bs)
+ io $ GHC.setContext s new_as new_bs
+ where
+ do_checks True = do
+ as' <- mapM wantInterpretedModule as
+ bs' <- mapM lookupModule bs
+ return (as',bs')
+ do_checks False = do
+ as' <- mapM (trymaybe . wantInterpretedModule) as
+ bs' <- mapM (trymaybe . lookupModule) bs
+ return (catMaybes as', catMaybes bs')
+
+ trymaybe m = do
+ r <- ghciTry m
+ case r of
+ Left _ -> return Nothing
+ Right a -> return (Just a)
----------------------------------------------------------------------------
-- Code for `:set'
,Opt_PrintEvldWithShow
]
setCmd str
- = case toArgs str of
- ("args":args) -> setArgs args
- ("prog":prog) -> setProg prog
- ("prompt":_) -> setPrompt (after 6)
- ("editor":_) -> setEditor (after 6)
- ("stop":_) -> setStop (after 4)
- wds -> setOptions wds
- where after n = dropWhile isSpace $ drop n $ dropWhile isSpace str
-
-setArgs, setProg, setOptions :: [String] -> GHCi ()
-setEditor, setStop, setPrompt :: String -> GHCi ()
+ = case getCmd str of
+ Right ("args", rest) ->
+ case toArgs rest of
+ Left err -> io (hPutStrLn stderr err)
+ Right args -> setArgs args
+ Right ("prog", rest) ->
+ case toArgs rest of
+ Right [prog] -> setProg prog
+ _ -> io (hPutStrLn stderr "syntax: :set prog <progname>")
+ Right ("prompt", rest) -> setPrompt $ dropWhile isSpace rest
+ Right ("editor", rest) -> setEditor $ dropWhile isSpace rest
+ Right ("stop", rest) -> setStop $ dropWhile isSpace rest
+ _ -> case toArgs str of
+ Left err -> io (hPutStrLn stderr err)
+ Right wds -> setOptions wds
+
+setArgs, setOptions :: [String] -> GHCi ()
+setProg, setEditor, setStop, setPrompt :: String -> GHCi ()
setArgs args = do
st <- getGHCiState
setGHCiState st{ args = args }
-setProg [prog] = do
+setProg prog = do
st <- getGHCiState
setGHCiState st{ progname = prog }
-setProg _ = do
- io (hPutStrLn stderr "syntax: :set prog <progname>")
setEditor cmd = do
st <- getGHCiState
io (GHC.load session LoadAllTargets)
io (linkPackages dflags new_pkgs)
-- package flags changed, we can't re-use any of the old context
- setContextAfterLoad session ([],[]) []
+ setContextAfterLoad session ([],[]) False []
return ()
["context"] -> showContext
["packages"] -> showPackages
["languages"] -> showLanguages
- _ -> throwDyn (CmdLineError "syntax: :show [args|prog|prompt|editor|stop|modules|bindings|breaks|context]")
+ _ -> throwDyn (CmdLineError ("syntax: :show [ args | prog | prompt | editor | stop | modules | bindings\n"++
+ " | breaks | context | packages | languages ]"))
showModules :: GHCi ()
showModules = do
ghciUnblock :: GHCi a -> GHCi a
ghciUnblock (GHCi a) = GHCi $ \s -> Exception.unblock (a s)
+ghciTry :: GHCi a -> GHCi (Either Exception a)
+ghciTry (GHCi m) = GHCi $ \s -> Exception.try (m s)
-- ----------------------------------------------------------------------------
-- Utils
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
+ Nothing ->
+ printForUser $ text "Not stopped at a breakpoint; nothing to list"
+ Just span
+ | GHC.isGoodSrcSpan span -> io $ listAround span True
+ | otherwise ->
+ do s <- getSession
+ resumes <- io $ GHC.getResumeContext s
+ case resumes of
+ [] -> panic "No resumes"
+ (r:_) ->
+ do let traceIt = case GHC.resumeHistory r of
+ [] -> text "rerunning with :trace,"
+ _ -> empty
+ doWhat = traceIt <+> text ":back then :list"
+ printForUser (text "Unable to list source for" <+>
+ ppr span
+ $$ text "Try" <+> doWhat)
listCmd str = list2 (words str)
list2 :: [String] -> GHCi ()
setBreakFlag toggle array index
| toggle = GHC.setBreakOn array index
| otherwise = GHC.setBreakOff array index
-