Document -fwarn-lazy-unlifted-bindings

[ghc-hetmet.git] / ghc / InteractiveUI.hs

diff --git a/ghc/InteractiveUI.hs b/ghc/InteractiveUI.hs
index 4aa441e..d620290 100644 (file)
--- a/ghc/InteractiveUI.hs
+++ b/ghc/InteractiveUI.hs
@@ -2,6 +2,7 @@
 -- -fno-cse is needed for GLOBAL_VAR's to behave properly
 
 {-# OPTIONS -#include "Linker.h" #-}
+{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 -----------------------------------------------------------------------------
 --
 -- GHC Interactive User Interface
@@ -38,6 +39,7 @@ import Outputable       hiding (printForUser, printForUserPartWay)
 import Module           -- for ModuleEnv
 import Name
 import SrcLoc
+import ObjLink
 
 -- Other random utilities
 import CmdLineParser
@@ -285,6 +287,13 @@ findEditor = do
 interactiveUI :: [(FilePath, Maybe Phase)] -> Maybe [String]
               -> Ghc ()
 interactiveUI srcs maybe_exprs = do
+   -- although GHCi compiles with -prof, it is not usable: the byte-code
+   -- compiler and interpreter don't work with profiling.  So we check for
+   -- this up front and emit a helpful error message (#2197)
+   m <- liftIO $ lookupSymbol "PushCostCentre"
+   when (isJust m) $ 
+     ghcError (InstallationError "GHCi cannot be used when compiled with -prof")
+
    -- 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
@@ -411,7 +420,7 @@ runGHCi paths maybe_exprs = do
         Nothing ->
           do
             -- enter the interactive loop
-            runGHCiInput $ runCommands $ haskelineLoop show_prompt
+            runGHCiInput $ runCommands $ nextInputLine show_prompt is_tty
         Just exprs -> do
             -- just evaluate the expression we were given
             enqueueCommands exprs
@@ -439,13 +448,14 @@ runGHCiInput f = do
         setLogAction
         f
 
--- TODO really bad name
-haskelineLoop :: Bool -> InputT GHCi (Maybe String)
-haskelineLoop show_prompt = do
+nextInputLine :: Bool -> Bool -> InputT GHCi (Maybe String)
+nextInputLine show_prompt is_tty
+  | is_tty = do
     prompt <- if show_prompt then lift mkPrompt else return ""
-    l <- getInputLine prompt
-    return l
-
+    getInputLine prompt
+  | otherwise = do
+    when show_prompt $ lift mkPrompt >>= liftIO . putStr
+    fileLoop stdin
 
 -- NOTE: We only read .ghci files if they are owned by the current user,
 -- and aren't world writable.  Otherwise, we could be accidentally 
@@ -481,7 +491,7 @@ checkPerms name =
 
 fileLoop :: MonadIO m => Handle -> InputT m (Maybe String)
 fileLoop hdl = do
-   l <- liftIO $ IO.try (BS.hGetLine hdl)
+   l <- liftIO $ IO.try $ hGetLine hdl
    case l of
         Left e | isEOFError e              -> return Nothing
                | InvalidArgument <- etype  -> return Nothing
@@ -491,7 +501,7 @@ fileLoop hdl = do
                 -- this can happen if the user closed stdin, or
                 -- perhaps did getContents which closes stdin at
                 -- EOF.
-        Right l -> fmap Just (Encoding.decode l)
+        Right l -> fmap Just (Encoding.decode (BS.pack l))
 
 mkPrompt :: GHCi String
 mkPrompt = do