- return (gbl_names ++ lcl_names)
-
-
--- ToDo: move to RdrName
-greToRdrNames :: GlobalRdrElt -> [RdrName]
-greToRdrNames GRE{ gre_name = name, gre_prov = prov }
- = case prov of
- LocalDef -> [unqual]
- Imported specs -> concat (map do_spec (map is_decl specs))
- where
- occ = nameOccName name
- unqual = Unqual occ
- do_spec decl_spec
- | is_qual decl_spec = [qual]
- | otherwise = [unqual,qual]
- where qual = Qual (is_as decl_spec) occ
-
--- | Parses a string as an identifier, and returns the list of 'Name's that
--- the identifier can refer to in the current interactive context.
-parseName :: Session -> String -> IO [Name]
-parseName s str = withSession s $ \hsc_env -> do
- maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
- case maybe_rdr_name of
- Nothing -> return []
- Just (L _ rdr_name) -> do
- mb_names <- tcRnLookupRdrName hsc_env rdr_name
- case mb_names of
- Nothing -> return []
- Just ns -> return ns
- -- ToDo: should return error messages
-
--- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
--- entity known to GHC, including 'Name's defined using 'runStmt'.
-lookupName :: Session -> Name -> IO (Maybe TyThing)
-lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
-
--- -----------------------------------------------------------------------------
--- Getting the type of an expression
-
--- | Get the type of an expression
-exprType :: Session -> String -> IO (Maybe Type)
-exprType s expr = withSession s $ \hsc_env -> do
- maybe_stuff <- hscTcExpr hsc_env expr
- case maybe_stuff of
- Nothing -> return Nothing
- Just ty -> return (Just tidy_ty)
- where
- tidy_ty = tidyType emptyTidyEnv ty
-
--- -----------------------------------------------------------------------------
--- Getting the kind of a type
-
--- | Get the kind of a type
-typeKind :: Session -> String -> IO (Maybe Kind)
-typeKind s str = withSession s $ \hsc_env -> do
- maybe_stuff <- hscKcType hsc_env str
- case maybe_stuff of
- Nothing -> return Nothing
- Just kind -> return (Just kind)
-
------------------------------------------------------------------------------
--- cmCompileExpr: compile an expression and deliver an HValue
-
-compileExpr :: Session -> String -> IO (Maybe HValue)
-compileExpr s expr = withSession s $ \hsc_env -> do
- maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
- case maybe_stuff of
- Nothing -> return Nothing
- Just (new_ic, names, hval) -> do
- -- Run it!
- hvals <- (unsafeCoerce# hval) :: IO [HValue]
-
- case (names,hvals) of
- ([n],[hv]) -> return (Just hv)
- _ -> panic "compileExpr"
-
--- -----------------------------------------------------------------------------
--- Compile an expression into a dynamic
-
-dynCompileExpr :: Session -> String -> IO (Maybe Dynamic)
-dynCompileExpr ses expr = do
- (full,exports) <- getContext ses
- setContext ses full $
- (mkModule
- (stringToPackageId "base") (mkModuleName "Data.Dynamic")
- ):exports
- let stmt = "let __dynCompileExpr = Data.Dynamic.toDyn (" ++ expr ++ ")"
- res <- withSession ses (flip hscStmt stmt)
- setContext ses full exports
- case res of
- Nothing -> return Nothing
- Just (_, names, hvals) -> do
- vals <- (unsafeCoerce# hvals :: IO [Dynamic])
- case (names,vals) of
- (_:[], v:[]) -> return (Just v)
- _ -> panic "dynCompileExpr"
-
--- -----------------------------------------------------------------------------
--- running a statement interactively
-
-data RunResult
- = RunOk [Name] -- ^ names bound by this evaluation
- | RunFailed -- ^ statement failed compilation
- | RunException Exception -- ^ statement raised an exception
- | RunBreak ThreadId [Name] BreakInfo ResumeHandle
-
-data Status
- = Break HValue BreakInfo ThreadId
- -- ^ the computation hit a breakpoint
- | Complete (Either Exception [HValue])
- -- ^ the computation completed with either an exception or a value
-
--- | This is a token given back to the client when runStmt stops at a
--- breakpoint. It allows the original computation to be resumed, restoring
--- the old interactive context.
-data ResumeHandle
- = ResumeHandle
- ThreadId -- thread running the computation
- (MVar ()) -- breakMVar
- (MVar Status) -- statusMVar
- [Name] -- [Name] to bind on completion
- InteractiveContext -- IC on completion
- InteractiveContext -- IC to restore on resumption
- [Name] -- [Name] to remove from the link env
-
--- We need to track two InteractiveContexts:
--- - the IC before runStmt, which is restored on each resume
--- - the IC binding the results of the original statement, which
--- will be the IC when runStmt returns with RunOk.
-
--- | Run a statement in the current interactive context. Statement
--- may bind multple values.
-runStmt :: Session -> String -> IO RunResult
-runStmt (Session ref) expr
- = do
- hsc_env <- readIORef ref
-
- breakMVar <- newEmptyMVar -- wait on this when we hit a breakpoint
- statusMVar <- newEmptyMVar -- wait on this when a computation is running
-
- -- Turn off -fwarn-unused-bindings when running a statement, to hide
- -- warnings about the implicit bindings we introduce.
- let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
- hsc_env' = hsc_env{ hsc_dflags = dflags' }
-
- maybe_stuff <- hscStmt hsc_env' expr
-
- case maybe_stuff of
- Nothing -> return RunFailed
- Just (new_IC, names, hval) -> do
-
- -- set the onBreakAction to be performed when we hit a
- -- breakpoint this is visible in the Byte Code
- -- Interpreter, thus it is a global variable,
- -- implemented with stable pointers
- withBreakAction breakMVar statusMVar $ do
-
- let thing_to_run = unsafeCoerce# hval :: IO [HValue]
- status <- sandboxIO statusMVar thing_to_run
- handleRunStatus ref new_IC names (hsc_IC hsc_env)
- breakMVar statusMVar status
-
-handleRunStatus ref final_ic final_names resume_ic breakMVar statusMVar status =
- case status of
- -- did we hit a breakpoint or did we complete?
- (Break apStack info tid) -> do
- hsc_env <- readIORef ref
- mod_info <- getHomeModuleInfo hsc_env (moduleName (breakInfo_module info))
- let breaks = minf_modBreaks (expectJust "handlRunStatus" mod_info)
- let index = breakInfo_number info
- occs = modBreaks_vars breaks ! index
- span = modBreaks_locs breaks ! index
- (new_hsc_env, names) <- extendEnvironment hsc_env apStack span
- (breakInfo_vars info)
- (breakInfo_resty info) occs
- writeIORef ref new_hsc_env
- let res = ResumeHandle breakMVar statusMVar final_names
- final_ic resume_ic names
- return (RunBreak tid names info res)
- (Complete either_hvals) ->
- case either_hvals of
- Left e -> return (RunException e)
- Right hvals -> do
- hsc_env <- readIORef ref
- writeIORef ref hsc_env{hsc_IC=final_ic}
- Linker.extendLinkEnv (zip final_names hvals)
- return (RunOk final_names)
-
--- this points to the IO action that is executed when a breakpoint is hit
-foreign import ccall "&breakPointIOAction"
- breakPointIOAction :: Ptr (StablePtr (BreakInfo -> HValue -> IO ()))
-
--- When running a computation, we redirect ^C exceptions to the running
--- thread. ToDo: we might want a way to continue even if the target
--- thread doesn't die when it receives the exception... "this thread
--- is not responding".
-sandboxIO :: MVar Status -> IO [HValue] -> IO Status
-sandboxIO statusMVar thing = do
- ts <- takeMVar interruptTargetThread
- child <- forkIO (do res <- Exception.try thing; putMVar statusMVar (Complete res))
- putMVar interruptTargetThread (child:ts)
- takeMVar statusMVar `finally` modifyMVar_ interruptTargetThread (return.tail)
-
-withBreakAction breakMVar statusMVar io
- = bracket setBreakAction resetBreakAction (\_ -> io)
- where
- setBreakAction = do
- stablePtr <- newStablePtr onBreak
- poke breakPointIOAction stablePtr
- return stablePtr
-
- onBreak info apStack = do
- tid <- myThreadId
- putMVar statusMVar (Break apStack info tid)
- takeMVar breakMVar
-
- resetBreakAction stablePtr = do
- poke breakPointIOAction noBreakStablePtr
- freeStablePtr stablePtr
-
-noBreakStablePtr = unsafePerformIO $ newStablePtr noBreakAction
-noBreakAction info apStack = putStrLn "*** Ignoring breakpoint"
-
-resume :: Session -> ResumeHandle -> IO RunResult
-resume (Session ref) res@(ResumeHandle breakMVar statusMVar
- final_names final_ic resume_ic names)
- = do
- -- restore the original interactive context. This is not entirely
- -- satisfactory: any new bindings made since the breakpoint stopped
- -- will be dropped from the interactive context, but not from the
- -- linker's environment.
- hsc_env <- readIORef ref
- writeIORef ref hsc_env{ hsc_IC = resume_ic }
- Linker.deleteFromLinkEnv names
-
- withBreakAction breakMVar statusMVar $ do
- putMVar breakMVar () -- this awakens the stopped thread...
- status <- takeMVar statusMVar -- and wait for the result
- handleRunStatus ref final_ic final_names resume_ic
- breakMVar statusMVar status
-
-{-
--- This version of sandboxIO runs the expression in a completely new
--- RTS main thread. It is disabled for now because ^C exceptions
--- won't be delivered to the new thread, instead they'll be delivered
--- to the (blocked) GHCi main thread.
-
--- SLPJ: when re-enabling this, reflect a wrong-stat error as an exception
-
-sandboxIO :: IO a -> IO (Either Int (Either Exception a))
-sandboxIO thing = do
- st_thing <- newStablePtr (Exception.try thing)
- alloca $ \ p_st_result -> do
- stat <- rts_evalStableIO st_thing p_st_result
- freeStablePtr st_thing
- if stat == 1
- then do st_result <- peek p_st_result
- result <- deRefStablePtr st_result
- freeStablePtr st_result
- return (Right result)
- else do
- return (Left (fromIntegral stat))
-
-foreign import "rts_evalStableIO" {- safe -}
- rts_evalStableIO :: StablePtr (IO a) -> Ptr (StablePtr a) -> IO CInt
- -- more informative than the C type!