DynFlags: move temp file management into HscEnv (#17957)

8 files changed, 173 insertions, 178 deletions

diff --git a/compiler/GHC/Driver/CodeOutput.hs b/compiler/GHC/Driver/CodeOutput.hs
index b459b7b447..8c990b16cb 100644
--- a/compiler/GHC/Driver/CodeOutput.hs
+++ b/compiler/GHC/Driver/CodeOutput.hs
@@ -36,7 +36,7 @@ import qualified GHC.Data.ShortText as ST
 import GHC.Data.Stream           ( Stream )
 import qualified GHC.Data.Stream as Stream
 
-import GHC.SysTools.FileCleanup
+import GHC.Utils.TmpFs
 
 
 import GHC.Utils.Error
@@ -66,23 +66,24 @@ import System.IO
 ************************************************************************
 -}
 
-codeOutput :: Logger
-           -> DynFlags
-           -> UnitState
-           -> Module
-           -> FilePath
-           -> ModLocation
-           -> (a -> ForeignStubs)
-           -> [(ForeignSrcLang, FilePath)]
-           -- ^ additional files to be compiled with the C compiler
-           -> [UnitId]
-           -> Stream IO RawCmmGroup a                       -- Compiled C--
-           -> IO (FilePath,
-                  (Bool{-stub_h_exists-}, Maybe FilePath{-stub_c_exists-}),
-                  [(ForeignSrcLang, FilePath)]{-foreign_fps-},
-                  a)
-
-codeOutput logger dflags unit_state this_mod filenm location genForeignStubs foreign_fps pkg_deps
+codeOutput
+    :: Logger
+    -> TmpFs
+    -> DynFlags
+    -> UnitState
+    -> Module
+    -> FilePath
+    -> ModLocation
+    -> (a -> ForeignStubs)
+    -> [(ForeignSrcLang, FilePath)]
+    -- ^ additional files to be compiled with the C compiler
+    -> [UnitId]
+    -> Stream IO RawCmmGroup a                       -- Compiled C--
+    -> IO (FilePath,
+           (Bool{-stub_h_exists-}, Maybe FilePath{-stub_c_exists-}),
+           [(ForeignSrcLang, FilePath)]{-foreign_fps-},
+           a)
+codeOutput logger tmpfs dflags unit_state this_mod filenm location genForeignStubs foreign_fps pkg_deps
   cmm_stream
   =
     do  {
@@ -117,7 +118,7 @@ codeOutput logger dflags unit_state this_mod filenm location genForeignStubs for
                  Interpreter -> panic "codeOutput: Interpreter"
                  NoBackend   -> panic "codeOutput: NoBackend"
         ; let stubs = genForeignStubs a
-        ; stubs_exist <- outputForeignStubs logger dflags unit_state this_mod location stubs
+        ; stubs_exist <- outputForeignStubs logger tmpfs dflags unit_state this_mod location stubs
         ; return (filenm, stubs_exist, foreign_fps, a)
         }
 
@@ -198,13 +199,20 @@ outputLlvm logger dflags filenm cmm_stream =
 ************************************************************************
 -}
 
-outputForeignStubs :: Logger -> DynFlags -> UnitState -> Module -> ModLocation -> ForeignStubs
-                   -> IO (Bool,         -- Header file created
-                          Maybe FilePath) -- C file created
-outputForeignStubs logger dflags unit_state mod location stubs
+outputForeignStubs
+    :: Logger
+    -> TmpFs
+    -> DynFlags
+    -> UnitState
+    -> Module
+    -> ModLocation
+    -> ForeignStubs
+    -> IO (Bool,         -- Header file created
+           Maybe FilePath) -- C file created
+outputForeignStubs logger tmpfs dflags unit_state mod location stubs
  = do
    let stub_h = mkStubPaths dflags (moduleName mod) location
-   stub_c <- newTempName logger dflags TFL_CurrentModule "c"
+   stub_c <- newTempName logger tmpfs dflags TFL_CurrentModule "c"
 
    case stubs of
      NoStubs ->
diff --git a/compiler/GHC/Driver/Env/Types.hs b/compiler/GHC/Driver/Env/Types.hs
index e541dfe544..23282eab27 100644
--- a/compiler/GHC/Driver/Env/Types.hs
+++ b/compiler/GHC/Driver/Env/Types.hs
@@ -22,6 +22,7 @@ import GHC.Unit.Env
 import GHC.Unit.State
 import GHC.Unit.Types
 import GHC.Utils.Logger
+import GHC.Utils.TmpFs
 import {-# SOURCE #-} GHC.Driver.Plugins
 
 import Control.Monad ( ap )
@@ -159,5 +160,8 @@ data HscEnv
 
         , hsc_hooks :: !Hooks
                 -- ^ Hooks
+
+        , hsc_tmpfs :: !TmpFs
+                -- ^ Temporary files
  }
 
diff --git a/compiler/GHC/Driver/Main.hs b/compiler/GHC/Driver/Main.hs
index d3695177d3..5be42094a0 100644
--- a/compiler/GHC/Driver/Main.hs
+++ b/compiler/GHC/Driver/Main.hs
@@ -207,6 +207,7 @@ import GHC.Utils.Outputable
 import GHC.Utils.Exception
 import GHC.Utils.Misc
 import GHC.Utils.Logger
+import GHC.Utils.TmpFs
 
 import GHC.Data.FastString
 import GHC.Data.Bag
@@ -248,6 +249,7 @@ newHscEnv dflags = do
     fc_var  <- newIORef emptyInstalledModuleEnv
     emptyLoader <- uninitializedLoader
     logger  <- initLogger
+    tmpfs   <- initTmpFs
     -- FIXME: it's sad that we have so many "unitialized" fields filled with
     -- empty stuff or lazy panics. We should have two kinds of HscEnv
     -- (initialized or not) instead and less fields that are mutable over time.
@@ -268,6 +270,7 @@ newHscEnv dflags = do
                   ,  hsc_static_plugins = []
                   ,  hsc_unit_dbs       = Nothing
                   ,  hsc_hooks          = emptyHooks
+                  ,  hsc_tmpfs          = tmpfs
                   }
 
 -- -----------------------------------------------------------------------------
@@ -1528,6 +1531,7 @@ hscGenHardCode hsc_env cgguts location output_filename = do
             dflags = hsc_dflags hsc_env
             logger = hsc_logger hsc_env
             hooks  = hsc_hooks hsc_env
+            tmpfs  = hsc_tmpfs hsc_env
             data_tycons = filter isDataTyCon tycons
             -- cg_tycons includes newtypes, for the benefit of External Core,
             -- but we don't generate any code for newtypes
@@ -1581,7 +1585,7 @@ hscGenHardCode hsc_env cgguts location output_filename = do
 
             (output_filename, (_stub_h_exists, stub_c_exists), foreign_fps, cg_infos)
                 <- {-# SCC "codeOutput" #-}
-                  codeOutput logger dflags (hsc_units hsc_env) this_mod output_filename location
+                  codeOutput logger tmpfs dflags (hsc_units hsc_env) this_mod output_filename location
                   foreign_stubs foreign_files dependencies rawcmms1
             return (output_filename, stub_c_exists, foreign_fps, cg_infos)
 
@@ -1593,6 +1597,7 @@ hscInteractive :: HscEnv
 hscInteractive hsc_env cgguts location = do
     let dflags = hsc_dflags hsc_env
     let logger = hsc_logger hsc_env
+    let tmpfs  = hsc_tmpfs hsc_env
     let CgGuts{ -- This is the last use of the ModGuts in a compilation.
                 -- From now on, we just use the bits we need.
                cg_module   = this_mod,
@@ -1615,7 +1620,7 @@ hscInteractive hsc_env cgguts location = do
     comp_bc <- byteCodeGen hsc_env this_mod prepd_binds data_tycons mod_breaks
     ------------------ Create f-x-dynamic C-side stuff -----
     (_istub_h_exists, istub_c_exists)
-        <- outputForeignStubs logger dflags (hsc_units hsc_env) this_mod location foreign_stubs
+        <- outputForeignStubs logger tmpfs dflags (hsc_units hsc_env) this_mod location foreign_stubs
     return (istub_c_exists, comp_bc, spt_entries)
 
 ------------------------------
@@ -1625,6 +1630,7 @@ hscCompileCmmFile hsc_env filename output_filename = runHsc hsc_env $ do
     let dflags   = hsc_dflags hsc_env
     let logger   = hsc_logger hsc_env
     let hooks    = hsc_hooks hsc_env
+    let tmpfs    = hsc_tmpfs hsc_env
         home_unit = hsc_home_unit hsc_env
         platform  = targetPlatform dflags
         -- Make up a module name to give the NCG. We can't pass bottom here
@@ -1661,7 +1667,7 @@ hscCompileCmmFile hsc_env filename output_filename = runHsc hsc_env $ do
               in NoStubs `appendStubC` ip_init
 
         (_output_filename, (_stub_h_exists, stub_c_exists), _foreign_fps, _caf_infos)
-          <- codeOutput logger dflags (hsc_units hsc_env) cmm_mod output_filename no_loc foreign_stubs [] []
+          <- codeOutput logger tmpfs dflags (hsc_units hsc_env) cmm_mod output_filename no_loc foreign_stubs [] []
              rawCmms
         return stub_c_exists
   where
@@ -1703,14 +1709,15 @@ doCodeGen hsc_env this_mod denv data_tycons
     let dflags = hsc_dflags hsc_env
     let logger = hsc_logger hsc_env
     let hooks  = hsc_hooks hsc_env
-        platform = targetPlatform dflags
+    let tmpfs  = hsc_tmpfs hsc_env
+    let platform = targetPlatform dflags
 
     let stg_binds_w_fvs = annTopBindingsFreeVars stg_binds
 
     dumpIfSet_dyn logger dflags Opt_D_dump_stg_final "Final STG:" FormatSTG (pprGenStgTopBindings (initStgPprOpts dflags) stg_binds_w_fvs)
 
     let stg_to_cmm = case stgToCmmHook hooks of
-                        Nothing -> StgToCmm.codeGen logger
+                        Nothing -> StgToCmm.codeGen logger tmpfs
                         Just h  -> h
 
     let cmm_stream :: Stream IO CmmGroup (CStub, ModuleLFInfos)
diff --git a/compiler/GHC/Driver/Make.hs b/compiler/GHC/Driver/Make.hs
index f13d13b198..bd885d9042 100644
--- a/compiler/GHC/Driver/Make.hs
+++ b/compiler/GHC/Driver/Make.hs
@@ -83,7 +83,7 @@ import GHC.Utils.Panic
 import GHC.Utils.Misc
 import GHC.Utils.Error
 import GHC.Utils.Logger
-import GHC.SysTools.FileCleanup
+import GHC.Utils.TmpFs
 
 import GHC.Types.Basic
 import GHC.Types.Target
@@ -568,8 +568,6 @@ load' how_much mHscMessage mod_graph = do
         -- an unstable module (#7231).
         mg = fmap (fmap ModuleNode) stable_mg ++ unstable_mg
 
-    -- clean up between compilations
-    let cleanup hsc_env = cleanCurrentModuleTempFiles (hsc_logger hsc_env) (hsc_dflags hsc_env)
     liftIO $ debugTraceMsg logger dflags 2 (hang (text "Ready for upsweep")
                                2 (ppr mg))
 
@@ -581,7 +579,7 @@ load' how_much mHscMessage mod_graph = do
 
     setSession hsc_env{ hsc_HPT = emptyHomePackageTable }
     (upsweep_ok, modsUpswept) <- withDeferredDiagnostics $
-      upsweep_fn mHscMessage pruned_hpt stable_mods cleanup mg
+      upsweep_fn mHscMessage pruned_hpt stable_mods mg
 
     -- Make modsDone be the summaries for each home module now
     -- available; this should equal the domain of hpt3.
@@ -601,7 +599,7 @@ load' how_much mHscMessage mod_graph = do
 
           -- Clean up after ourselves
           hsc_env1 <- getSession
-          liftIO $ cleanCurrentModuleTempFiles logger dflags
+          liftIO $ cleanCurrentModuleTempFiles logger (hsc_tmpfs hsc_env1) dflags
 
           -- Issue a warning for the confusing case where the user
           -- said '-o foo' but we're not going to do any linking.
@@ -620,6 +618,7 @@ load' how_much mHscMessage mod_graph = do
           hsc_env <- getSession
           linkresult <- liftIO $ link (ghcLink dflags)
                                       logger
+                                      (hsc_tmpfs hsc_env)
                                       (hsc_hooks hsc_env)
                                       dflags
                                       (hsc_unit_env hsc_env)
@@ -665,9 +664,9 @@ load' how_much mHscMessage mod_graph = do
                         lookupHpt hpt4 (moduleName ms_mod)
                         >>= hm_linkable
                 ]
-          liftIO $
-            changeTempFilesLifetime dflags TFL_CurrentModule unneeded_temps
-          liftIO $ cleanCurrentModuleTempFiles logger dflags
+          tmpfs <- hsc_tmpfs <$> getSession
+          liftIO $ changeTempFilesLifetime tmpfs TFL_CurrentModule unneeded_temps
+          liftIO $ cleanCurrentModuleTempFiles logger tmpfs dflags
 
           let hpt5 = retainInTopLevelEnvs (map ms_mod_name mods_to_keep)
                                           hpt4
@@ -686,6 +685,7 @@ load' how_much mHscMessage mod_graph = do
           hsc_env <- getSession
           linkresult <- liftIO $ link (ghcLink dflags)
                                       logger
+                                      (hsc_tmpfs hsc_env)
                                       (hsc_hooks hsc_env)
                                       dflags
                                       (hsc_unit_env hsc_env)
@@ -1067,14 +1067,14 @@ parUpsweep
     -> Maybe Messager
     -> HomePackageTable
     -> StableModules
-    -> (HscEnv -> IO ())
     -> [SCC ModuleGraphNode]
     -> m (SuccessFlag,
           [ModuleGraphNode])
-parUpsweep n_jobs mHscMessage old_hpt stable_mods cleanup sccs = do
+parUpsweep n_jobs mHscMessage old_hpt stable_mods sccs = do
     hsc_env <- getSession
     let dflags = hsc_dflags hsc_env
     let logger = hsc_logger hsc_env
+    let tmpfs  = hsc_tmpfs hsc_env
 
     -- The bits of shared state we'll be using:
 
@@ -1176,18 +1176,15 @@ parUpsweep n_jobs mHscMessage old_hpt stable_mods cleanup sccs = do
                 -- deal with synchronously printing these messages.
                 let lcl_logger = pushLogHook (const (parLogAction log_queue)) thread_safe_logger
 
-                --
-                -- Use a local filesToClean var so that we can clean up
-                -- intermediate files in a timely fashion (as soon as
-                -- compilation for that module is finished) without having to
-                -- worry about accidentally deleting a simultaneous compile's
-                -- important files.
-                lcl_files_to_clean <- newIORef emptyFilesToClean
-                let lcl_dflags = dflags { filesToClean = lcl_files_to_clean }
+                -- Use a local TmpFs so that we can clean up intermediate files
+                -- in a timely fashion (as soon as compilation for that module
+                -- is finished) without having to worry about accidentally
+                -- deleting a simultaneous compile's important files.
+                lcl_tmpfs <- forkTmpFsFrom tmpfs
 
                 -- Unmask asynchronous exceptions and perform the thread-local
                 -- work to compile the module (see parUpsweep_one).
-                m_res <- MC.try $ unmask $ prettyPrintGhcErrors lcl_dflags $
+                m_res <- MC.try $ unmask $ prettyPrintGhcErrors dflags $
                   case mod of
                     InstantiationNode iuid -> do
                       hsc_env <- readMVar hsc_env_var
@@ -1195,8 +1192,8 @@ parUpsweep n_jobs mHscMessage old_hpt stable_mods cleanup sccs = do
                       pure Succeeded
                     ModuleNode ems ->
                       parUpsweep_one (emsModSummary ems) home_mod_map comp_graph_loops
-                                     lcl_logger lcl_dflags (hsc_home_unit hsc_env)
-                                     mHscMessage cleanup
+                                     lcl_logger lcl_tmpfs dflags (hsc_home_unit hsc_env)
+                                     mHscMessage
                                      par_sem hsc_env_var old_hpt_var
                                      stable_mods mod_idx (length sccs)
 
@@ -1208,7 +1205,7 @@ parUpsweep n_jobs mHscMessage old_hpt stable_mods cleanup sccs = do
                         -- interrupt, and the user doesn't have to be informed
                         -- about that.
                         when (fromException exc /= Just ThreadKilled)
-                             (errorMsg lcl_logger lcl_dflags (text (show exc)))
+                             (errorMsg lcl_logger dflags (text (show exc)))
                         return Failed
 
                 -- Populate the result MVar.
@@ -1220,13 +1217,8 @@ parUpsweep n_jobs mHscMessage old_hpt stable_mods cleanup sccs = do
                 writeLogQueue log_queue Nothing
 
                 -- Add the remaining files that weren't cleaned up to the
-                -- global filesToClean ref, for cleanup later.
-                FilesToClean
-                  { ftcCurrentModule = cm_files
-                  , ftcGhcSession = gs_files
-                  } <- readIORef (filesToClean lcl_dflags)
-                addFilesToClean dflags TFL_CurrentModule $ Set.toList cm_files
-                addFilesToClean dflags TFL_GhcSession $ Set.toList gs_files
+                -- global TmpFs, for cleanup later.
+                mergeTmpFsInto lcl_tmpfs tmpfs
 
         -- Kill all the workers, masking interrupts (since killThread is
         -- interruptible). XXX: This is not ideal.
@@ -1298,14 +1290,14 @@ parUpsweep_one
     -- ^ The list of all module loops within the compilation graph.
     -> Logger
     -- ^ The thread-local Logger
+    -> TmpFs
+    -- ^ The thread-local TmpFs
     -> DynFlags
     -- ^ The thread-local DynFlags
     -> HomeUnit
     -- ^ The home-unit
     -> Maybe Messager
     -- ^ The messager
-    -> (HscEnv -> IO ())
-    -- ^ The callback for cleaning up intermediate files
     -> QSem
     -- ^ The semaphore for limiting the number of simultaneous compiles
     -> MVar HscEnv
@@ -1320,7 +1312,7 @@ parUpsweep_one
     -- ^ The total number of modules
     -> IO SuccessFlag
     -- ^ The result of this compile
-parUpsweep_one mod home_mod_map comp_graph_loops lcl_logger lcl_dflags home_unit mHscMessage cleanup par_sem
+parUpsweep_one mod home_mod_map comp_graph_loops lcl_logger lcl_tmpfs lcl_dflags home_unit mHscMessage par_sem
                hsc_env_var old_hpt_var stable_mods mod_index num_mods = do
 
     let this_build_mod = mkBuildModule0 mod
@@ -1430,9 +1422,7 @@ parUpsweep_one mod home_mod_map comp_graph_loops lcl_logger lcl_dflags home_unit
         let withSem sem = MC.bracket_ (waitQSem sem) (signalQSem sem)
         mb_mod_info <- withSem par_sem $
             handleSourceError (\err -> do logg err; return Nothing) $ do
-                -- Have the ModSummary and HscEnv point to our local log_action
-                -- and filesToClean var.
-                let lcl_mod = localize_mod mod
+                -- Have the HscEnv point to our local logger and tmpfs.
                 let lcl_hsc_env = localize_hsc_env hsc_env
 
                 -- Re-typecheck the loop
@@ -1440,7 +1430,7 @@ parUpsweep_one mod home_mod_map comp_graph_loops lcl_logger lcl_dflags home_unit
                 -- we close a recursive module loop, see bug #12035.
                 type_env_var <- liftIO $ newIORef emptyNameEnv
                 let lcl_hsc_env' = lcl_hsc_env { hsc_type_env_var =
-                                    Just (ms_mod lcl_mod, type_env_var) }
+                                    Just (ms_mod mod, type_env_var) }
                 lcl_hsc_env'' <- case finish_loop of
                     Nothing   -> return lcl_hsc_env'
                     -- In the non-parallel case, the retypecheck prior to
@@ -1454,7 +1444,7 @@ parUpsweep_one mod home_mod_map comp_graph_loops lcl_logger lcl_dflags home_unit
 
                 -- Compile the module.
                 mod_info <- upsweep_mod lcl_hsc_env'' mHscMessage old_hpt stable_mods
-                                        lcl_mod mod_index num_mods
+                                        mod mod_index num_mods
                 return (Just mod_info)
 
         case mb_mod_info of
@@ -1483,18 +1473,16 @@ parUpsweep_one mod home_mod_map comp_graph_loops lcl_logger lcl_dflags home_unit
                     return (hsc_env'', localize_hsc_env hsc_env'')
 
                 -- Clean up any intermediate files.
-                cleanup lcl_hsc_env'
+                cleanCurrentModuleTempFiles (hsc_logger lcl_hsc_env')
+                                            (hsc_tmpfs  lcl_hsc_env')
+                                            (hsc_dflags lcl_hsc_env')
                 return Succeeded
 
   where
-    localize_mod mod
-        = mod { ms_hspp_opts = (ms_hspp_opts mod)
-                 { filesToClean = filesToClean lcl_dflags } }
-
     localize_hsc_env hsc_env
         = hsc_env { hsc_logger = lcl_logger
-                  , hsc_dflags = (hsc_dflags hsc_env)
-                     { filesToClean = filesToClean lcl_dflags } }
+                  , hsc_tmpfs  = lcl_tmpfs
+                  }
 
 -- -----------------------------------------------------------------------------
 --
@@ -1510,7 +1498,6 @@ upsweep
     => Maybe Messager
     -> HomePackageTable            -- ^ HPT from last time round (pruned)
     -> StableModules               -- ^ stable modules (see checkStability)
-    -> (HscEnv -> IO ())           -- ^ How to clean up unwanted tmp files
     -> [SCC ModuleGraphNode]       -- ^ Mods to do (the worklist)
     -> m (SuccessFlag,
           [ModuleGraphNode])
@@ -1520,7 +1507,7 @@ upsweep
        --  2. The 'HscEnv' in the monad has an updated HPT
        --  3. A list of modules which succeeded loading.
 
-upsweep mHscMessage old_hpt stable_mods cleanup sccs = do
+upsweep mHscMessage old_hpt stable_mods sccs = do
    (res, done) <- upsweep' old_hpt emptyMG sccs 1 (length sccs)
    return (res, reverse $ mgModSummaries' done)
  where
@@ -1588,7 +1575,9 @@ upsweep mHscMessage old_hpt stable_mods cleanup sccs = do
         hsc_env <- getSession
 
         -- Remove unwanted tmp files between compilations
-        liftIO (cleanup hsc_env)
+        liftIO $ cleanCurrentModuleTempFiles (hsc_logger hsc_env)
+                                             (hsc_tmpfs  hsc_env)
+                                             (hsc_dflags hsc_env)
 
         -- Get ready to tie the knot
         type_env_var <- liftIO $ newIORef emptyNameEnv
@@ -2274,10 +2263,11 @@ downsweep hsc_env old_summaries excl_mods allow_dup_roots
        -- otherwise those modules will fail to compile.
        -- See Note [-fno-code mode] #8025
        let default_backend = platformDefaultBackend (targetPlatform dflags)
-           home_unit       = hsc_home_unit hsc_env
+       let home_unit       = hsc_home_unit hsc_env
+       let tmpfs           = hsc_tmpfs     hsc_env
        map1 <- case backend dflags of
-         NoBackend   -> enableCodeGenForTH logger home_unit default_backend map0
-         Interpreter -> enableCodeGenForUnboxedTuplesOrSums logger default_backend map0
+         NoBackend   -> enableCodeGenForTH logger tmpfs home_unit default_backend map0
+         Interpreter -> enableCodeGenForUnboxedTuplesOrSums logger tmpfs default_backend map0
          _           -> return map0
        if null errs
          then pure $ concat $ modNodeMapElems map1
@@ -2372,12 +2362,13 @@ downsweep hsc_env old_summaries excl_mods allow_dup_roots
 -- See Note [-fno-code mode]
 enableCodeGenForTH
   :: Logger
+  -> TmpFs
   -> HomeUnit
   -> Backend
   -> ModNodeMap [Either ErrorMessages ExtendedModSummary]
   -> IO (ModNodeMap [Either ErrorMessages ExtendedModSummary])
-enableCodeGenForTH logger home_unit =
-  enableCodeGenWhen logger condition should_modify TFL_CurrentModule TFL_GhcSession
+enableCodeGenForTH logger tmpfs home_unit =
+  enableCodeGenWhen logger tmpfs condition should_modify TFL_CurrentModule TFL_GhcSession
   where
     condition = isTemplateHaskellOrQQNonBoot
     should_modify (ModSummary { ms_hspp_opts = dflags }) =
@@ -2395,11 +2386,12 @@ enableCodeGenForTH logger home_unit =
 -- or sums into GHCi while still allowing some code to be interpreted.
 enableCodeGenForUnboxedTuplesOrSums
   :: Logger
+  -> TmpFs
   -> Backend
   -> ModNodeMap [Either ErrorMessages ExtendedModSummary]
   -> IO (ModNodeMap [Either ErrorMessages ExtendedModSummary])
-enableCodeGenForUnboxedTuplesOrSums logger =
-  enableCodeGenWhen logger condition should_modify TFL_GhcSession TFL_CurrentModule
+enableCodeGenForUnboxedTuplesOrSums logger tmpfs =
+  enableCodeGenWhen logger tmpfs condition should_modify TFL_GhcSession TFL_CurrentModule
   where
     condition ms =
       unboxed_tuples_or_sums (ms_hspp_opts ms) &&
@@ -2418,6 +2410,7 @@ enableCodeGenForUnboxedTuplesOrSums logger =
 -- marking modules for code generation.
 enableCodeGenWhen
   :: Logger
+  -> TmpFs
   -> (ModSummary -> Bool)
   -> (ModSummary -> Bool)
   -> TempFileLifetime
@@ -2425,7 +2418,7 @@ enableCodeGenWhen
   -> Backend
   -> ModNodeMap [Either ErrorMessages ExtendedModSummary]
   -> IO (ModNodeMap [Either ErrorMessages ExtendedModSummary])
-enableCodeGenWhen logger condition should_modify staticLife dynLife bcknd nodemap =
+enableCodeGenWhen logger tmpfs condition should_modify staticLife dynLife bcknd nodemap =
   traverse (traverse (traverse enable_code_gen)) nodemap
   where
     enable_code_gen :: ExtendedModSummary -> IO ExtendedModSummary
@@ -2440,9 +2433,9 @@ enableCodeGenWhen logger condition should_modify staticLife dynLife bcknd nodema
       , ms_mod `Set.member` needs_codegen_set
       = do
         let new_temp_file suf dynsuf = do
-              tn <- newTempName logger dflags staticLife suf
+              tn <- newTempName logger tmpfs dflags staticLife suf
               let dyn_tn = tn -<.> dynsuf
-              addFilesToClean dflags dynLife [dyn_tn]
+              addFilesToClean tmpfs dynLife [dyn_tn]
               return tn
           -- We don't want to create .o or .hi files unless we have been asked
           -- to by the user. But we need them, so we patch their locations in
diff --git a/compiler/GHC/Driver/MakeFile.hs b/compiler/GHC/Driver/MakeFile.hs
index 57377212cb..f71b2e17b9 100644
--- a/compiler/GHC/Driver/MakeFile.hs
+++ b/compiler/GHC/Driver/MakeFile.hs
@@ -31,7 +31,7 @@ import GHC.Types.SourceError
 import GHC.Types.SrcLoc
 import Data.List (partition)
 import GHC.Data.FastString
-import GHC.SysTools.FileCleanup
+import GHC.Utils.TmpFs
 
 import GHC.Iface.Load (cannotFindModule)
 
@@ -82,7 +82,8 @@ doMkDependHS srcs = do
     when (null (depSuffixes dflags)) $ liftIO $
         throwGhcExceptionIO (ProgramError "You must specify at least one -dep-suffix")
 
-    files <- liftIO $ beginMkDependHS logger dflags
+    tmpfs <- hsc_tmpfs <$> getSession
+    files <- liftIO $ beginMkDependHS logger tmpfs dflags
 
     -- Do the downsweep to find all the modules
     targets <- mapM (\s -> GHC.guessTarget s Nothing) srcs
@@ -131,11 +132,11 @@ data MkDepFiles
             mkd_tmp_file  :: FilePath,          -- Name of the temporary file
             mkd_tmp_hdl   :: Handle }           -- Handle of the open temporary file
 
-beginMkDependHS :: Logger -> DynFlags -> IO MkDepFiles
-beginMkDependHS logger dflags = do
+beginMkDependHS :: Logger -> TmpFs -> DynFlags -> IO MkDepFiles
+beginMkDependHS logger tmpfs dflags = do
         -- open a new temp file in which to stuff the dependency info
         -- as we go along.
-  tmp_file <- newTempName logger dflags TFL_CurrentModule "dep"
+  tmp_file <- newTempName logger tmpfs dflags TFL_CurrentModule "dep"
   tmp_hdl <- openFile tmp_file WriteMode
 
         -- open the makefile
diff --git a/compiler/GHC/Driver/Pipeline.hs b/compiler/GHC/Driver/Pipeline.hs
index f2e740ac41..bf9fbe8405 100644
--- a/compiler/GHC/Driver/Pipeline.hs
+++ b/compiler/GHC/Driver/Pipeline.hs
@@ -62,7 +62,7 @@ import GHC.Parser.Header
 import GHC.Parser.Errors.Ppr
 
 import GHC.SysTools
-import GHC.SysTools.FileCleanup
+import GHC.Utils.TmpFs
 
 import GHC.Linker.ExtraObj
 import GHC.Linker.Dynamic
@@ -196,6 +196,7 @@ compileOne' m_tc_result mHscMessage
  = do
 
    let logger = hsc_logger hsc_env0
+   let tmpfs  = hsc_tmpfs hsc_env0
    debugTraceMsg logger dflags1 2 (text "compile: input file" <+> text input_fnpp)
 
    -- Run the pipeline up to codeGen (so everything up to, but not including, STG)
@@ -208,10 +209,10 @@ compileOne' m_tc_result mHscMessage
 
    let flags = hsc_dflags hsc_env0
      in do unless (gopt Opt_KeepHiFiles flags) $
-               addFilesToClean flags TFL_CurrentModule $
+               addFilesToClean tmpfs TFL_CurrentModule $
                    [ml_hi_file $ ms_location summary]
            unless (gopt Opt_KeepOFiles flags) $
-               addFilesToClean flags TFL_GhcSession $
+               addFilesToClean tmpfs TFL_GhcSession $
                    [ml_obj_file $ ms_location summary]
 
    case (status, bcknd) of
@@ -236,7 +237,7 @@ compileOne' m_tc_result mHscMessage
             let !linkable = LM (ms_hs_date summary) this_mod []
             return $! HomeModInfo iface hmi_details (Just linkable)
         (HscUpdateSig iface hmi_details, _) -> do
-            output_fn <- getOutputFilename logger next_phase
+            output_fn <- getOutputFilename logger tmpfs next_phase
                             (Temporary TFL_CurrentModule) basename dflags
                             next_phase (Just location)
 
@@ -286,7 +287,7 @@ compileOne' m_tc_result mHscMessage
                            (hs_unlinked ++ stub_o)
             return $! HomeModInfo final_iface hmi_details (Just linkable)
         (HscRecomp{}, _) -> do
-            output_fn <- getOutputFilename logger next_phase
+            output_fn <- getOutputFilename logger tmpfs next_phase
                             (Temporary TFL_CurrentModule)
                             basename dflags next_phase (Just location)
             -- We're in --make mode: finish the compilation pipeline.
@@ -418,7 +419,8 @@ compileEmptyStub dflags hsc_env basename location mod_name = do
   -- https://gitlab.haskell.org/ghc/ghc/issues/12673
   -- and https://github.com/haskell/cabal/issues/2257
   let logger = hsc_logger hsc_env
-  empty_stub <- newTempName logger dflags TFL_CurrentModule "c"
+  let tmpfs  = hsc_tmpfs hsc_env
+  empty_stub <- newTempName logger tmpfs dflags TFL_CurrentModule "c"
   let home_unit = hsc_home_unit hsc_env
       src = text "int" <+> ppr (mkHomeModule home_unit mod_name) <+> text "= 0;"
   writeFile empty_stub (showSDoc dflags (pprCode CStyle src))
@@ -484,6 +486,7 @@ compileEmptyStub dflags hsc_env basename location mod_name = do
 -- libraries.
 link :: GhcLink                 -- ^ interactive or batch
      -> Logger                  -- ^ Logger
+     -> TmpFs
      -> Hooks
      -> DynFlags                -- ^ dynamic flags
      -> UnitEnv                 -- ^ unit environment
@@ -498,13 +501,13 @@ link :: GhcLink                 -- ^ interactive or batch
 -- exports main, i.e., we have good reason to believe that linking
 -- will succeed.
 
-link ghcLink logger hooks dflags unit_env batch_attempt_linking hpt =
+link ghcLink logger tmpfs hooks dflags unit_env batch_attempt_linking hpt =
   case linkHook hooks of
       Nothing -> case ghcLink of
           NoLink        -> return Succeeded
-          LinkBinary    -> link' logger dflags unit_env batch_attempt_linking hpt
-          LinkStaticLib -> link' logger dflags unit_env batch_attempt_linking hpt
-          LinkDynLib    -> link' logger dflags unit_env batch_attempt_linking hpt
+          LinkBinary    -> link' logger tmpfs dflags unit_env batch_attempt_linking hpt
+          LinkStaticLib -> link' logger tmpfs dflags unit_env batch_attempt_linking hpt
+          LinkDynLib    -> link' logger tmpfs dflags unit_env batch_attempt_linking hpt
           LinkInMemory
               | platformMisc_ghcWithInterpreter $ platformMisc dflags
               -> -- Not Linking...(demand linker will do the job)
@@ -519,13 +522,14 @@ panicBadLink other = panic ("link: GHC not built to link this way: " ++
                             show other)
 
 link' :: Logger
+      -> TmpFs
       -> DynFlags                -- ^ dynamic flags
       -> UnitEnv                 -- ^ unit environment
       -> Bool                    -- ^ attempt linking in batch mode?
       -> HomePackageTable        -- ^ what to link
       -> IO SuccessFlag
 
-link' logger dflags unit_env batch_attempt_linking hpt
+link' logger tmpfs dflags unit_env batch_attempt_linking hpt
    | batch_attempt_linking
    = do
         let
@@ -565,11 +569,11 @@ link' logger dflags unit_env batch_attempt_linking hpt
 
         -- Don't showPass in Batch mode; doLink will do that for us.
         let link = case ghcLink dflags of
-                LinkBinary    -> linkBinary
-                LinkStaticLib -> linkStaticLib
-                LinkDynLib    -> linkDynLibCheck
+                LinkBinary    -> linkBinary logger tmpfs
+                LinkStaticLib -> linkStaticLib logger
+                LinkDynLib    -> linkDynLibCheck logger tmpfs
                 other         -> panicBadLink other
-        link logger dflags unit_env obj_files pkg_deps
+        link dflags unit_env obj_files pkg_deps
 
         debugTraceMsg logger dflags 3 (text "link: done")
 
@@ -678,11 +682,12 @@ doLink hsc_env stop_phase o_files
         dflags   = hsc_dflags   hsc_env
         logger   = hsc_logger   hsc_env
         unit_env = hsc_unit_env hsc_env
+        tmpfs    = hsc_tmpfs    hsc_env
     in case ghcLink dflags of
         NoLink        -> return ()
-        LinkBinary    -> linkBinary         logger dflags unit_env o_files []
-        LinkStaticLib -> linkStaticLib      logger dflags unit_env o_files []
-        LinkDynLib    -> linkDynLibCheck    logger dflags unit_env o_files []
+        LinkBinary    -> linkBinary         logger tmpfs dflags unit_env o_files []
+        LinkStaticLib -> linkStaticLib      logger       dflags unit_env o_files []
+        LinkDynLib    -> linkDynLibCheck    logger tmpfs dflags unit_env o_files []
         other         -> panicBadLink other
 
 
@@ -719,6 +724,7 @@ runPipeline stop_phase hsc_env0 (input_fn, mb_input_buf, mb_phase)
              dflags = dflags0 { dumpPrefix = Just (basename ++ ".") }
              hsc_env = hsc_env0 {hsc_dflags = dflags}
              logger = hsc_logger hsc_env
+             tmpfs  = hsc_tmpfs  hsc_env
 
              (input_basename, suffix) = splitExtension input_fn
              suffix' = drop 1 suffix -- strip off the .
@@ -766,7 +772,7 @@ runPipeline stop_phase hsc_env0 (input_fn, mb_input_buf, mb_phase)
          input_fn' <- case (start_phase, mb_input_buf) of
              (RealPhase real_start_phase, Just input_buf) -> do
                  let suffix = phaseInputExt real_start_phase
-                 fn <- newTempName logger dflags TFL_CurrentModule suffix
+                 fn <- newTempName logger tmpfs dflags TFL_CurrentModule suffix
                  hdl <- openBinaryFile fn WriteMode
                  -- Add a LINE pragma so reported source locations will
                  -- mention the real input file, not this temp file.
@@ -869,7 +875,8 @@ pipeLoop phase input_fn = do
             return input_fn
         output ->
             do pst <- getPipeState
-               final_fn <- liftIO $ getOutputFilename logger
+               tmpfs <- hsc_tmpfs <$> getPipeSession
+               final_fn <- liftIO $ getOutputFilename logger tmpfs
                                         stopPhase output (src_basename env)
                                         dflags stopPhase (maybe_loc pst)
                when (final_fn /= input_fn) $ do
@@ -954,10 +961,11 @@ runHookedPhase pp input = do
 phaseOutputFilename :: Phase{-next phase-} -> CompPipeline FilePath
 phaseOutputFilename next_phase = do
   PipeEnv{stop_phase, src_basename, output_spec} <- getPipeEnv
-  PipeState{maybe_loc} <- getPipeState
+  PipeState{maybe_loc,hsc_env} <- getPipeState
   dflags <- getDynFlags
   logger <- getLogger
-  liftIO $ getOutputFilename logger stop_phase output_spec
+  let tmpfs = hsc_tmpfs hsc_env
+  liftIO $ getOutputFilename logger tmpfs stop_phase output_spec
                              src_basename dflags next_phase maybe_loc
 
 -- | Computes the next output filename for something in the compilation
@@ -976,17 +984,24 @@ phaseOutputFilename next_phase = do
 --         compiling; this can be used to override the default output
 --         of an object file.  (TODO: do we actually need this?)
 getOutputFilename
-  :: Logger -> Phase -> PipelineOutput -> String
-  -> DynFlags -> Phase{-next phase-} -> Maybe ModLocation -> IO FilePath
-getOutputFilename logger stop_phase output basename dflags next_phase maybe_location
+  :: Logger
+  -> TmpFs
+  -> Phase
+  -> PipelineOutput
+  -> String
+  -> DynFlags
+  -> Phase -- next phase
+  -> Maybe ModLocation
+  -> IO FilePath
+getOutputFilename logger tmpfs stop_phase output basename dflags next_phase maybe_location
  | is_last_phase, Persistent   <- output = persistent_fn
  | is_last_phase, SpecificFile <- output = case outputFile dflags of
                                            Just f -> return f
                                            Nothing ->
                                                panic "SpecificFile: No filename"
  | keep_this_output                      = persistent_fn
- | Temporary lifetime <- output          = newTempName logger dflags lifetime suffix
- | otherwise                             = newTempName logger dflags TFL_CurrentModule
+ | Temporary lifetime <- output          = newTempName logger tmpfs dflags lifetime suffix
+ | otherwise                             = newTempName logger tmpfs dflags TFL_CurrentModule
    suffix
     where
           hcsuf      = hcSuf dflags
@@ -1160,7 +1175,10 @@ runPhase (RealPhase (Cpp sf)) input_fn
         else do
             output_fn <- phaseOutputFilename (HsPp sf)
             hsc_env <- getPipeSession
-            liftIO $ doCpp logger (hsc_dflags hsc_env) (hsc_unit_env hsc_env)
+            liftIO $ doCpp logger
+                           (hsc_tmpfs hsc_env)
+                           (hsc_dflags hsc_env)
+                           (hsc_unit_env hsc_env)
                            True{-raw-}
                            input_fn output_fn
             -- re-read the pragmas now that we've preprocessed the file
@@ -1389,7 +1407,10 @@ runPhase (RealPhase CmmCpp) input_fn = do
        hsc_env <- getPipeSession
        logger <- getLogger
        output_fn <- phaseOutputFilename Cmm
-       liftIO $ doCpp logger (hsc_dflags hsc_env) (hsc_unit_env hsc_env)
+       liftIO $ doCpp logger
+                      (hsc_tmpfs hsc_env)
+                      (hsc_dflags hsc_env)
+                      (hsc_unit_env hsc_env)
                       False{-not raw-}
                       input_fn output_fn
        return (RealPhase Cmm, output_fn)
@@ -1415,6 +1436,7 @@ runPhase (RealPhase cc_phase) input_fn
         let dflags    = hsc_dflags hsc_env
         let unit_env  = hsc_unit_env hsc_env
         let home_unit = hsc_home_unit hsc_env
+        let tmpfs     = hsc_tmpfs hsc_env
         let platform  = ue_platform unit_env
         let hcc       = cc_phase `eqPhase` HCc
 
@@ -1492,7 +1514,7 @@ runPhase (RealPhase cc_phase) input_fn
         ghcVersionH <- liftIO $ getGhcVersionPathName dflags unit_env
 
         logger <- getLogger
-        liftIO $ GHC.SysTools.runCc (phaseForeignLanguage cc_phase) logger dflags (
+        liftIO $ GHC.SysTools.runCc (phaseForeignLanguage cc_phase) logger tmpfs dflags (
                         [ GHC.SysTools.FileOption "" input_fn
                         , GHC.SysTools.Option "-o"
                         , GHC.SysTools.FileOption "" output_fn
@@ -1747,7 +1769,7 @@ runPhase (RealPhase LlvmMangle) input_fn = do
 -- merge in stub objects
 
 runPhase (RealPhase MergeForeign) input_fn = do
-     PipeState{foreign_os} <- getPipeState
+     PipeState{foreign_os,hsc_env} <- getPipeState
      output_fn <- phaseOutputFilename StopLn
      liftIO $ createDirectoryIfMissing True (takeDirectory output_fn)
      if null foreign_os
@@ -1755,7 +1777,8 @@ runPhase (RealPhase MergeForeign) input_fn = do
        else do
          dflags <- getDynFlags
          logger <- getLogger
-         liftIO $ joinObjectFiles logger dflags (input_fn : foreign_os) output_fn
+         let tmpfs = hsc_tmpfs hsc_env
+         liftIO $ joinObjectFiles logger tmpfs dflags (input_fn : foreign_os) output_fn
          return (RealPhase StopLn, output_fn)
 
 -- warning suppression
@@ -1830,14 +1853,14 @@ getHCFilePackages filename =
           return []
 
 
-linkDynLibCheck :: Logger -> DynFlags -> UnitEnv -> [String] -> [UnitId] -> IO ()
-linkDynLibCheck logger dflags unit_env o_files dep_units = do
+linkDynLibCheck :: Logger -> TmpFs -> DynFlags -> UnitEnv -> [String] -> [UnitId] -> IO ()
+linkDynLibCheck logger tmpfs dflags unit_env o_files dep_units = do
   when (haveRtsOptsFlags dflags) $
     putLogMsg logger dflags NoReason SevInfo noSrcSpan
       $ withPprStyle defaultUserStyle
       (text "Warning: -rtsopts and -with-rtsopts have no effect with -shared." $$
       text "    Call hs_init_ghc() from your main() function to set these options.")
-  linkDynLib logger dflags unit_env o_files dep_units
+  linkDynLib logger tmpfs dflags unit_env o_files dep_units
 
 
 -- -----------------------------------------------------------------------------
@@ -1846,8 +1869,8 @@ linkDynLibCheck logger dflags unit_env o_files dep_units = do
 -- | Run CPP
 --
 -- UnitState is needed to compute MIN_VERSION macros
-doCpp :: Logger -> DynFlags -> UnitEnv -> Bool -> FilePath -> FilePath -> IO ()
-doCpp logger dflags unit_env raw input_fn output_fn = do
+doCpp :: Logger -> TmpFs -> DynFlags -> UnitEnv -> Bool -> FilePath -> FilePath -> IO ()
+doCpp logger tmpfs dflags unit_env raw input_fn output_fn = do
     let hscpp_opts = picPOpts dflags
     let cmdline_include_paths = includePaths dflags
     let unit_state = ue_units unit_env
@@ -1862,7 +1885,8 @@ doCpp logger dflags unit_env raw input_fn output_fn = do
     let verbFlags = getVerbFlags dflags
 
     let cpp_prog args | raw       = GHC.SysTools.runCpp logger dflags args
-                      | otherwise = GHC.SysTools.runCc Nothing logger dflags (GHC.SysTools.Option "-E" : args)
+                      | otherwise = GHC.SysTools.runCc Nothing logger tmpfs dflags
+                                        (GHC.SysTools.Option "-E" : args)
 
     let platform   = targetPlatform dflags
         targetArch = stringEncodeArch $ platformArch platform
@@ -1905,7 +1929,7 @@ doCpp logger dflags unit_env raw input_fn output_fn = do
         pkgs = catMaybes (map (lookupUnit unit_state) uids)
     mb_macro_include <-
         if not (null pkgs) && gopt Opt_VersionMacros dflags
-            then do macro_stub <- newTempName logger dflags TFL_CurrentModule "h"
+            then do macro_stub <- newTempName logger tmpfs dflags TFL_CurrentModule "h"
                     writeFile macro_stub (generatePackageVersionMacros pkgs)
                     -- Include version macros for every *exposed* package.
                     -- Without -hide-all-packages and with a package database
@@ -2035,12 +2059,12 @@ via gcc.
 
 -}
 
-joinObjectFiles :: Logger -> DynFlags -> [FilePath] -> FilePath -> IO ()
-joinObjectFiles logger dflags o_files output_fn = do
+joinObjectFiles :: Logger -> TmpFs -> DynFlags -> [FilePath] -> FilePath -> IO ()
+joinObjectFiles logger tmpfs dflags o_files output_fn = do
   let toolSettings' = toolSettings dflags
       ldIsGnuLd = toolSettings_ldIsGnuLd toolSettings'
       osInfo = platformOS (targetPlatform dflags)
-      ld_r args = GHC.SysTools.runMergeObjects logger dflags (
+      ld_r args = GHC.SysTools.runMergeObjects logger tmpfs dflags (
                         -- See Note [Produce big objects on Windows]
                         concat
                           [ [GHC.SysTools.Option "--oformat", GHC.SysTools.Option "pe-bigobj-x86-64"]
@@ -2060,14 +2084,14 @@ joinObjectFiles logger dflags o_files output_fn = do
 
   if ldIsGnuLd
      then do
-          script <- newTempName logger dflags TFL_CurrentModule "ldscript"
+          script <- newTempName logger tmpfs dflags TFL_CurrentModule "ldscript"
           cwd <- getCurrentDirectory
           let o_files_abs = map (\x -> "\"" ++ (cwd </> x) ++ "\"") o_files
           writeFile script $ "INPUT(" ++ unwords o_files_abs ++ ")"
           ld_r [GHC.SysTools.FileOption "" script]
      else if toolSettings_ldSupportsFilelist toolSettings'
      then do
-          filelist <- newTempName logger dflags TFL_CurrentModule "filelist"
+          filelist <- newTempName logger tmpfs dflags TFL_CurrentModule "filelist"
           writeFile filelist $ unlines o_files
           ld_r [GHC.SysTools.Option "-filelist",
                 GHC.SysTools.FileOption "" filelist]
diff --git a/compiler/GHC/Driver/Pipeline/Monad.hs b/compiler/GHC/Driver/Pipeline/Monad.hs
index 53d4e98b0d..4a33543527 100644
--- a/compiler/GHC/Driver/Pipeline/Monad.hs
+++ b/compiler/GHC/Driver/Pipeline/Monad.hs
@@ -22,7 +22,7 @@ import GHC.Driver.Phases
 import GHC.Driver.Env
 import GHC.Driver.Plugins
 
-import GHC.SysTools.FileCleanup (TempFileLifetime)
+import GHC.Utils.TmpFs (TempFileLifetime)
 
 import GHC.Types.SourceFile
 
diff --git a/compiler/GHC/Driver/Session.hs b/compiler/GHC/Driver/Session.hs
index 3633edf48c..8b7ddd321d 100644
--- a/compiler/GHC/Driver/Session.hs
+++ b/compiler/GHC/Driver/Session.hs
@@ -209,9 +209,6 @@ module GHC.Driver.Session (
         LinkerInfo(..),
         CompilerInfo(..),
 
-        -- * File cleanup
-        FilesToClean(..), emptyFilesToClean,
-
         -- * Include specifications
         IncludeSpecs(..), addGlobalInclude, addQuoteInclude, flattenIncludes,
 
@@ -271,9 +268,6 @@ import Control.Monad.Trans.Except
 import Data.Ord
 import Data.Char
 import Data.List (intercalate, delete, sortBy)
-import Data.Map (Map)
-import qualified Data.Map as Map
-import Data.Set (Set)
 import qualified Data.Set as Set
 import System.FilePath
 import System.Directory
@@ -580,13 +574,6 @@ data DynFlags = DynFlags {
   packageEnv            :: Maybe FilePath,
         -- ^ Filepath to the package environment file (if overriding default)
 
-  -- Temporary files
-  -- These have to be IORefs, because the defaultCleanupHandler needs to
-  -- know what to clean when an exception happens
-  filesToClean          :: IORef FilesToClean,
-  dirsToClean           :: IORef (Map FilePath FilePath),
-  -- The next available suffix to uniquely name a temp file, updated atomically
-  nextTempSuffix        :: IORef Int,
 
   -- hsc dynamic flags
   dumpFlags             :: EnumSet DumpFlag,
@@ -1061,9 +1048,6 @@ initDynFlags dflags = do
      platformCanGenerateDynamicToo
          = platformOS (targetPlatform dflags) /= OSMinGW32
  refDynamicTooFailed <- newIORef (not platformCanGenerateDynamicToo)
- refNextTempSuffix <- newIORef 0
- refFilesToClean <- newIORef emptyFilesToClean
- refDirsToClean <- newIORef Map.empty
  refRtldInfo <- newIORef Nothing
  refRtccInfo <- newIORef Nothing
  wrapperNum <- newIORef emptyModuleEnv
@@ -1084,9 +1068,6 @@ initDynFlags dflags = do
        (useColor dflags, colScheme dflags)
  return dflags{
         dynamicTooFailed = refDynamicTooFailed,
-        nextTempSuffix = refNextTempSuffix,
-        filesToClean   = refFilesToClean,
-        dirsToClean    = refDirsToClean,
         nextWrapperNum = wrapperNum,
         useUnicode    = useUnicode',
         useColor      = useColor',
@@ -1212,9 +1193,6 @@ defaultDynFlags mySettings llvmConfig =
         depExcludeMods    = [],
         depSuffixes       = [],
         -- end of ghc -M values
-        nextTempSuffix = panic "defaultDynFlags: No nextTempSuffix",
-        filesToClean   = panic "defaultDynFlags: No filesToClean",
-        dirsToClean    = panic "defaultDynFlags: No dirsToClean",
         ghcVersionFile = Nothing,
         haddockOptions = Nothing,
         dumpFlags = EnumSet.empty,
@@ -4883,26 +4861,6 @@ decodeSize str
 foreign import ccall unsafe "setHeapSize"       setHeapSize       :: Int -> IO ()
 foreign import ccall unsafe "enableTimingStats" enableTimingStats :: IO ()
 
--- -----------------------------------------------------------------------------
--- Types for managing temporary files.
---
--- these are here because FilesToClean is used in DynFlags
-
--- | A collection of files that must be deleted before ghc exits.
--- The current collection
--- is stored in an IORef in DynFlags, 'filesToClean'.
-data FilesToClean = FilesToClean {
-  ftcGhcSession :: !(Set FilePath),
-  -- ^ Files that will be deleted at the end of runGhc(T)
-  ftcCurrentModule :: !(Set FilePath)
-  -- ^ Files that will be deleted the next time
-  -- 'FileCleanup.cleanCurrentModuleTempFiles' is called, or otherwise at the
-  -- end of the session.
-  }
-
--- | An empty FilesToClean
-emptyFilesToClean :: FilesToClean
-emptyFilesToClean = FilesToClean Set.empty Set.empty
 
 -- | Initialize the pretty-printing options
 initSDocContext :: DynFlags -> PprStyle -> SDocContext