[commit: ghc] master: This reverts commit 163de25813d12764aa5ded1666af7c06fee0d67e and commit 279ac9f66a83203448b279ea478b2cc1dafbd35d. (4115f23)

[Nicolas Frisby]

Repository : http://darcs.haskell.org/ghc.git/

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/4115f23c2df56fd8b30c62c78f41c091f9ca12a4

>---------------------------------------------------------------

commit 4115f23c2df56fd8b30c62c78f41c091f9ca12a4
Author: Nicolas Frisby <nicolas.frisby at gmail.com>
Date:   Sat Jul 6 12:43:57 2013 -0500

    This reverts commit 163de25813d12764aa5ded1666af7c06fee0d67e and commit 279ac9f66a83203448b279ea478b2cc1dafbd35d.

>---------------------------------------------------------------

 compiler/simplCore/CoreMonad.lhs |   49 +++++---------------------------------
 compiler/simplCore/SimplCore.lhs |    4 ++--
 compiler/utils/FastString.lhs    |   27 ++-------------------
 3 files changed, 10 insertions(+), 70 deletions(-)

diff --git a/compiler/simplCore/CoreMonad.lhs b/compiler/simplCore/CoreMonad.lhs
index 04cdc36..2475247 100644
--- a/compiler/simplCore/CoreMonad.lhs
+++ b/compiler/simplCore/CoreMonad.lhs
@@ -44,7 +44,7 @@ module CoreMonad (
     liftIO1, liftIO2, liftIO3, liftIO4,
     
     -- ** Global initialization
-    reinitializeGlobals, bracketGlobals,
+    reinitializeGlobals,
     
     -- ** Dealing with annotations
     getAnnotations, getFirstAnnotations,
@@ -722,12 +722,11 @@ data CoreReader = CoreReader {
         cr_hsc_env :: HscEnv,
         cr_rule_base :: RuleBase,
         cr_module :: Module,
-        cr_globals :: (,,)    (Bool, [String]) -- from StaticFlags
-                              FastStringTable  -- from FastString
+        cr_globals :: ((Bool, [String]),
 #ifdef GHCI
-                              (MVar PersistentLinkerState, Bool) -- from Linker
+                       (MVar PersistentLinkerState, Bool))
 #else
-                              ()
+                       ())
 #endif
 }
 
@@ -796,7 +795,7 @@ runCoreM :: HscEnv
          -> CoreM a
          -> IO (a, SimplCount)
 runCoreM hsc_env rule_base us mod m = do
-        glbls <- liftM3 (,,) saveStaticFlagGlobals saveFSTable saveLinkerGlobals
+        glbls <- liftM2 (,) saveStaticFlagGlobals saveLinkerGlobals
         liftM extract $ runIOEnv (reader glbls) $ unCoreM m state
   where
     reader glbls = CoreReader {
@@ -898,8 +897,6 @@ getOrigNameCache = do
 %*									*
 %************************************************************************
 
-Note [Initializing globals]
-
 This is a rather annoying function. When a plugin is loaded, it currently
 gets linked against a *newly loaded* copy of the GHC package. This would
 not be a problem, except that the new copy has its own mutable state
@@ -930,49 +927,15 @@ I've threaded the cr_globals through CoreM rather than giving them as an
 argument to the plugin function so that we can turn this function into
 (return ()) without breaking any plugins when we eventually get 1. working.
 
------
-
-We include the FastString table in this mechanism, because we'd like
-FastStrings created by the plugin to have the same uniques as similar strings
-created by the host compiler itself.  For example, this allows plugins to
-lookup known names (eg `mkTcOcc "MySpecialType"`) in the GlobalRdrEnv or even
-re-invoke the parser.
-
-In particular, the following little sanity test was failing in a plugin
-prototyping safe newtype-coercions.
-
-   let rdrName = mkModuleName "GHC.NT.Type" `mkRdrQual` mkTcOcc "NT"
-   putMsgS $ showSDoc dflags $ ppr $ lookupGRE_RdrName rdrName $ mg_rdr_env guts
-
-`mkTcOcc` involves the lookup (or creation) of a FastString.  Since the
-plugin's FastString.string_table is empty, constructing the RdrName also
-allocates new uniques for the FastStrings "GHC.NT.Type" and "NT".  These
-uniques are almost certainly unequal to the ones that the host compiler
-originally assigned to those FastStrings.  Thus the lookup fails since the
-domain of the GlobalRdrEnv is affected by the RdrName's OccName's FastString's
-unique.
-
 \begin{code}
--- called by plugin
 reinitializeGlobals :: CoreM ()
 reinitializeGlobals = do
-    (sf_globals, fs_table, linker_globals) <- read cr_globals
+    (sf_globals, linker_globals) <- read cr_globals
     hsc_env <- getHscEnv
     let dflags = hsc_dflags hsc_env
     liftIO $ restoreStaticFlagGlobals sf_globals
-    liftIO $ restoreFSTable fs_table
     liftIO $ restoreLinkerGlobals linker_globals
     liftIO $ setUnsafeGlobalDynFlags dflags
-
--- called by host compiler, assuming argument is code from a plugin
-bracketGlobals :: CoreM a -> CoreM a
-bracketGlobals (CoreM f) = do
-  tbl <- liftIO saveFSTable
-  let upd e = e {cr_globals=(x,tbl,z)}
-        where (x,_,z) = cr_globals e
-  x <- CoreM (\s -> updEnv upd (f s))
-  liftIO unsaveFSTable
-  return x
 \end{code}
 
 %************************************************************************
diff --git a/compiler/simplCore/SimplCore.lhs b/compiler/simplCore/SimplCore.lhs
index 9c67be9..62e167a 100644
--- a/compiler/simplCore/SimplCore.lhs
+++ b/compiler/simplCore/SimplCore.lhs
@@ -311,7 +311,7 @@ addPluginPasses dflags builtin_passes
        ; foldM query_plug builtin_passes named_plugins }
   where
     query_plug todos (mod_nm, plug)
-       = bracketGlobals $ installCoreToDos plug options todos
+       = installCoreToDos plug options todos
        where
          options = [ option | (opt_mod_nm, option) <- pluginModNameOpts dflags
                             , opt_mod_nm == mod_nm ]
@@ -407,7 +407,7 @@ doCorePass _      CoreDoNothing                = return
 doCorePass _      (CoreDoPasses passes)        = runCorePasses passes
 
 #ifdef GHCI
-doCorePass _      (CoreDoPluginPass _ pass) = {-# SCC "Plugin" #-} (bracketGlobals . pass)
+doCorePass _      (CoreDoPluginPass _ pass) = {-# SCC "Plugin" #-} pass
 #endif
 
 doCorePass _      pass = pprPanic "doCorePass" (ppr pass)
diff --git a/compiler/utils/FastString.lhs b/compiler/utils/FastString.lhs
index 5c6e7ff..36b1b1e 100644
--- a/compiler/utils/FastString.lhs
+++ b/compiler/utils/FastString.lhs
@@ -91,10 +91,7 @@ module FastString
         unpackLitString,
         
         -- ** Operations
-        lengthLS,
-
-        -- * Saving/restoring globals
-        saveFSTable, restoreFSTable, unsaveFSTable, FastStringTable
+        lengthLS
        ) where
 
 #include "HsVersions.h"
@@ -480,7 +477,7 @@ nilFS = mkFastString ""
 getFastStringTable :: IO [[FastString]]
 getFastStringTable = do
   tbl <- readIORef string_table
-  buckets <- mapM (lookupTbl tbl) [0 .. hASH_TBL_SIZE - 1]
+  buckets <- mapM (lookupTbl tbl) [0 .. hASH_TBL_SIZE]
   return buckets
 
 -- -----------------------------------------------------------------------------
@@ -576,24 +573,4 @@ fsLit x = mkFastString x
     forall x . sLit  (unpackCString# x) = mkLitString#  x #-}
 {-# RULES "fslit"
     forall x . fsLit (unpackCString# x) = mkFastString# x #-}
-
-
---------------------
--- for plugins; see Note [Initializing globals] in CoreMonad
-
--- called by host compiler
-saveFSTable :: IO FastStringTable
-saveFSTable = readIORef string_table
-
--- called by host compiler
-unsaveFSTable :: IO ()
-unsaveFSTable = do
-  tbl@(FastStringTable _ arr#) <- readIORef string_table
-  buckets <- mapM (lookupTbl tbl) [0 .. hASH_TBL_SIZE - 1]
-  let size = sum $ map length $ buckets
-  writeIORef string_table (FastStringTable size arr#)
-
--- called by plugin
-restoreFSTable :: FastStringTable -> IO ()
-restoreFSTable = writeIORef string_table
 \end{code}