Revert "Add -fghci-leak-check to check for space leaks"

This reverts commit 5fe6aaa3756cda654374ebfd883fa8f064ff64a4.

8 files changed, 2 insertions, 96 deletions

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 734c0a1fa9..6bfa8f2955 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -533,7 +533,6 @@ data GeneralFlag
    | Opt_IgnoreDotGhci
    | Opt_GhciSandbox
    | Opt_GhciHistory
-   | Opt_GhciLeakCheck
    | Opt_LocalGhciHistory
    | Opt_NoIt
    | Opt_HelpfulErrors
@@ -3935,7 +3934,6 @@ fFlagsDeps = [
   flagSpec "fun-to-thunk"                     Opt_FunToThunk,
   flagSpec "gen-manifest"                     Opt_GenManifest,
   flagSpec "ghci-history"                     Opt_GhciHistory,
-  flagSpec "ghci-leak-check"                  Opt_GhciLeakCheck,
   flagGhciSpec "local-ghci-history"           Opt_LocalGhciHistory,
   flagGhciSpec "no-it"                        Opt_NoIt,
   flagSpec "ghci-sandbox"                     Opt_GhciSandbox,
diff --git a/docs/users_guide/ghci.rst b/docs/users_guide/ghci.rst
index a5f5764a9e..f5dcfe3962 100644
--- a/docs/users_guide/ghci.rst
+++ b/docs/users_guide/ghci.rst
@@ -2025,17 +2025,6 @@ mostly obvious.
 
     It will create ``.ghci-history`` in current folder where GHCi is launched.
 
-.. ghc-flag:: -fghci-leak-check
-    :shortdesc: (Debugging only) check for space leaks when loading
-                new modules in GHCi.
-    :type: dynamic
-    :reverse: -fno-ghci-leak-check
-    :category:
-
-    (Debugging only) When loading new modules with ``:load``, check
-    that any previously loaded modules have been correctly garbage
-    collected. Emits messages if a leak is detected.
-
 Packages
 ~~~~~~~~
 
diff --git a/ghc/GHCi/Leak.hs b/ghc/GHCi/Leak.hs
deleted file mode 100644
index 3f64b5dcf0..0000000000
--- a/ghc/GHCi/Leak.hs
+++ /dev/null
@@ -1,59 +0,0 @@
-{-# LANGUAGE RecordWildCards, LambdaCase #-}
-module GHCi.Leak
-  ( LeakIndicators
-  , getLeakIndicators
-  , checkLeakIndicators
-  ) where
-
-import Control.Monad
-import GHC
-import Outputable
-import HscTypes
-import UniqDFM
-import System.Mem
-import System.Mem.Weak
-
--- Checking for space leaks in GHCi. See #15111, and the
--- -fghci-leak-check flag.
-
-data LeakIndicators = LeakIndicators [LeakModIndicators]
-
-data LeakModIndicators = LeakModIndicators
-  { leakMod :: Weak HomeModInfo
-  , leakIface :: Weak ModIface
-  , leakDetails :: Weak ModDetails
-  , leakLinkable :: Maybe (Weak Linkable)
-  }
-
--- | Grab weak references to some of the data structures representing
--- the currently loaded modules.
-getLeakIndicators :: HscEnv -> IO LeakIndicators
-getLeakIndicators HscEnv{..} =
-  fmap LeakIndicators $
-    forM (eltsUDFM hsc_HPT) $ \hmi@HomeModInfo{..} -> do
-      leakMod <- mkWeakPtr hmi Nothing
-      leakIface <- mkWeakPtr hm_iface Nothing
-      leakDetails <- mkWeakPtr hm_details Nothing
-      leakLinkable <- mapM (`mkWeakPtr` Nothing) hm_linkable
-      return $ LeakModIndicators{..}
-
--- | Look at the LeakIndicators collected by an earlier call to
--- `getLeakIndicators`, and print messasges if any of them are still
--- alive.
-checkLeakIndicators :: DynFlags -> LeakIndicators -> IO ()
-checkLeakIndicators dflags (LeakIndicators leakmods)  = do
-  performGC
-  forM_ leakmods $ \LeakModIndicators{..} -> do
-    deRefWeak leakMod >>= \case
-      Nothing -> return ()
-      Just hmi ->
-        report ("HomeModInfo for " ++
-          showSDoc dflags (ppr (mi_module (hm_iface hmi)))) (Just hmi)
-    deRefWeak leakIface >>= report "ModIface"
-    deRefWeak leakDetails >>= report "ModDetails"
-    forM_ leakLinkable $ \l -> deRefWeak l >>= report "Linkable"
- where
-  report :: String -> Maybe a -> IO ()
-  report _ Nothing = return ()
-  report msg (Just _) =
-    putStrLn ("-fghci-leak-check: " ++ msg ++ " is still alive!")
diff --git a/ghc/GHCi/UI.hs b/ghc/GHCi/UI.hs
index c97fb01033..349368b6d7 100644
--- a/ghc/GHCi/UI.hs
+++ b/ghc/GHCi/UI.hs
@@ -134,8 +134,6 @@ import GHC.IO.Exception ( IOErrorType(InvalidArgument) )
 import GHC.IO.Handle ( hFlushAll )
 import GHC.TopHandler ( topHandler )
 
-import GHCi.Leak
-
 -----------------------------------------------------------------------------
 
 data GhciSettings = GhciSettings {
@@ -1648,14 +1646,6 @@ loadModule' files = do
   -- require some re-working of the GHC interface, so we'll leave it
   -- as a ToDo for now.
 
-  hsc_env <- GHC.getSession
-
-  -- Grab references to the currently loaded modules so that we can
-  -- see if they leak.
-  leak_indicators <- if gopt Opt_GhciLeakCheck (hsc_dflags hsc_env)
-    then liftIO $ getLeakIndicators hsc_env
-    else return (panic "no leak indicators")
-
   -- unload first
   _ <- GHC.abandonAll
   lift discardActiveBreakPoints
@@ -1663,10 +1653,7 @@ loadModule' files = do
   _ <- GHC.load LoadAllTargets
 
   GHC.setTargets targets
-  success <- doLoadAndCollectInfo False LoadAllTargets
-  when (gopt Opt_GhciLeakCheck (hsc_dflags hsc_env)) $
-    liftIO $ checkLeakIndicators (hsc_dflags hsc_env) leak_indicators
-  return success
+  doLoadAndCollectInfo False LoadAllTargets
 
 -- | @:add@ command
 addModule :: [FilePath] -> InputT GHCi ()
diff --git a/ghc/ghc-bin.cabal.in b/ghc/ghc-bin.cabal.in
index 6c12941630..12812ef07c 100644
--- a/ghc/ghc-bin.cabal.in
+++ b/ghc/ghc-bin.cabal.in
@@ -61,7 +61,6 @@ Executable ghc
         CPP-Options: -DGHCI
         GHC-Options: -fno-warn-name-shadowing
         Other-Modules:
-            GHCi.Leak
             GHCi.UI
             GHCi.UI.Info
             GHCi.UI.Monad
diff --git a/testsuite/config/ghc b/testsuite/config/ghc
index f41f372cb2..6296394197 100644
--- a/testsuite/config/ghc
+++ b/testsuite/config/ghc
@@ -80,7 +80,7 @@ config.way_flags = {
     'prof_no_auto' : ['-prof', '-static', '-fasm'],
     'profasm'      : ['-O', '-prof', '-static', '-fprof-auto'],
     'profthreaded' : ['-O', '-prof', '-static', '-fprof-auto', '-threaded'],
-    'ghci'         : ['--interactive', '-v0', '-ignore-dot-ghci', '-fno-ghci-history', '-fghci-leak-check', '+RTS', '-I0.1', '-RTS'],
+    'ghci'         : ['--interactive', '-v0', '-ignore-dot-ghci', '-fno-ghci-history', '+RTS', '-I0.1', '-RTS'],
     'sanity'       : ['-debug'],
     'threaded1'    : ['-threaded', '-debug'],
     'threaded1_ls' : ['-threaded', '-debug'],
diff --git a/testsuite/tests/ghci/scripts/T9293.stdout b/testsuite/tests/ghci/scripts/T9293.stdout
index 4fdd3504bc..2e5adc404c 100644
--- a/testsuite/tests/ghci/scripts/T9293.stdout
+++ b/testsuite/tests/ghci/scripts/T9293.stdout
@@ -10,7 +10,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
@@ -30,7 +29,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
@@ -49,7 +47,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
@@ -70,7 +67,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
diff --git a/testsuite/tests/ghci/scripts/ghci057.stdout b/testsuite/tests/ghci/scripts/ghci057.stdout
index 4fdd3504bc..2e5adc404c 100644
--- a/testsuite/tests/ghci/scripts/ghci057.stdout
+++ b/testsuite/tests/ghci/scripts/ghci057.stdout
@@ -10,7 +10,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
@@ -30,7 +29,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
@@ -49,7 +47,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings:
@@ -70,7 +67,6 @@ other dynamic, non-language, flag settings:
   -fignore-optim-changes
   -fignore-hpc-changes
   -fno-ghci-history
-  -fghci-leak-check
   -fimplicit-import-qualified
   -fshow-warning-groups
 warning settings: