Revert "Make module membership on ModuleGraph faster"

I had not intended on merging this.

This reverts commit b0708588e87554899c2efc80a2d3eba353dbe926.

1 files changed, 20 insertions, 34 deletions

diff --git a/compiler/main/GhcMake.hs b/compiler/main/GhcMake.hs
index 57af356b38..134a0607bc 100644
--- a/compiler/main/GhcMake.hs
+++ b/compiler/main/GhcMake.hs
@@ -138,11 +138,9 @@ depanal excluded_mods allow_dup_roots = do
     -- cached finder data.
     liftIO $ flushFinderCaches hsc_env
 
-    mod_summariesE <- liftIO $ downsweep hsc_env (mgModSummaries old_graph)
+    mod_graphE <- liftIO $ downsweep hsc_env old_graph
                                      excluded_mods allow_dup_roots
-    mod_summaries <- reportImportErrors mod_summariesE
-
-    let mod_graph = mkModuleGraph mod_summaries
+    mod_graph <- reportImportErrors mod_graphE
 
     warnMissingHomeModules hsc_env mod_graph
 
@@ -195,7 +193,7 @@ warnMissingHomeModules hsc_env mod_graph =
     is_my_target _ _ = False
 
     missing = map (moduleName . ms_mod) $
-      filter (not . is_known_module) (mgModSummaries mod_graph)
+      filter (not . is_known_module) mod_graph
 
     msg = text "Modules are not listed in command line: "
         <> sep (map ppr missing)
@@ -250,7 +248,7 @@ load' how_much mHscMessage mod_graph = do
     -- (see msDeps)
     let all_home_mods =
           mkUniqSet [ ms_mod_name s
-                    | s <- mgModSummaries mod_graph, not (isBootSummary s)]
+                    | s <- mod_graph, not (isBootSummary s)]
     -- TODO: Figure out what the correct form of this assert is. It's violated
     -- when you have HsBootMerge nodes in the graph: then you'll have hs-boot
     -- files without corresponding hs files.
@@ -419,7 +417,7 @@ load' how_much mHscMessage mod_graph = do
           let no_hs_main = gopt Opt_NoHsMain dflags
           let
             main_mod = mainModIs dflags
-            a_root_is_Main = mgElemModule mod_graph main_mod
+            a_root_is_Main = any ((==main_mod).ms_mod) mod_graph
             do_linking = a_root_is_Main || no_hs_main || ghcLink dflags == LinkDynLib || ghcLink dflags == LinkStaticLib
 
           -- link everything together
@@ -540,7 +538,8 @@ guessOutputFile = modifySession $ \env ->
         !mod_graph = hsc_mod_graph env
         mainModuleSrcPath :: Maybe String
         mainModuleSrcPath = do
-            ms <- mgLookupModule mod_graph (mainModIs dflags)
+            let isMain = (== mainModIs dflags) . ms_mod
+            [ms] <- return (filter isMain mod_graph)
             ml_hs_file (ms_location ms)
         name = fmap dropExtension mainModuleSrcPath
 
@@ -885,15 +884,13 @@ parUpsweep n_jobs mHscMessage old_hpt stable_mods cleanup sccs = do
     -- The list of all loops in the compilation graph.
     -- NB: For convenience, the last module of each loop (aka the module that
     -- finishes the loop) is prepended to the beginning of the loop.
-    let comp_graph_loops = go graph
+    let comp_graph_loops = go (map fstOf3 (reverse comp_graph))
           where
-            graph = mkModuleGraph (map fstOf3 (reverse comp_graph))
-            go mg
-              | Just (ms, mg') <- mgHead mg =
-                case getModLoop ms mg of
-                 Just loop -> map mkBuildModule (ms:loop) : go mg'
-                 Nothing -> go mg'
-              | otherwise = []
+            go [] = []
+            go (ms:mss) | Just loop <- getModLoop ms (ms:mss)
+                        = map mkBuildModule (ms:loop) : go mss
+                        | otherwise
+                        = go mss
 
     -- Build a Map out of the compilation graph with which we can efficiently
     -- look up the result MVar associated with a particular home module.
@@ -1234,22 +1231,12 @@ upsweep
 
 upsweep mHscMessage old_hpt stable_mods cleanup sccs = do
    dflags <- getSessionDynFlags
-   (res, done) <- upsweep' old_hpt emptyMG sccs 1 (length sccs)
+   (res, done) <- upsweep' old_hpt [] sccs 1 (length sccs)
                            (unitIdsToCheck dflags) done_holes
-   return (res, reverse $ mgModSummaries done)
+   return (res, reverse done)
  where
   done_holes = emptyUniqSet
 
-  upsweep'
-    :: GhcMonad m
-    => HomePackageTable
-    -> ModuleGraph
-    -> [SCC ModSummary]
-    -> Int
-    -> Int
-    -> [UnitId]
-    -> UniqSet ModuleName
-    -> m (SuccessFlag, ModuleGraph)
   upsweep' _old_hpt done
      [] _ _ uids_to_check _
    = do hsc_env <- getSession
@@ -1327,7 +1314,7 @@ upsweep mHscMessage old_hpt stable_mods cleanup sccs = do
                     old_hpt1 | isBootSummary mod = old_hpt
                              | otherwise = delFromHpt old_hpt this_mod
 
-                    done' = extendMG done mod
+                    done' = mod:done
 
                         -- fixup our HomePackageTable after we've finished compiling
                         -- a mutually-recursive loop.  We have to do this again
@@ -1663,8 +1650,8 @@ reTypecheckLoop hsc_env ms graph
 getModLoop :: ModSummary -> ModuleGraph -> Maybe [ModSummary]
 getModLoop ms graph
   | not (isBootSummary ms)
-  , mgElemBootModule graph this_mod
-  , let mss = reachableBackwards (ms_mod_name ms) (mgModSummaries graph)
+  , any (\m -> ms_mod m == this_mod && isBootSummary m) graph
+  , let mss = reachableBackwards (ms_mod_name ms) graph
   = Just mss
   | otherwise
   = Nothing
@@ -1702,7 +1689,7 @@ reachableBackwards mod summaries
 topSortModuleGraph
           :: Bool
           -- ^ Drop hi-boot nodes? (see below)
-          -> ModuleGraph
+          -> [ModSummary]
           -> Maybe ModuleName
              -- ^ Root module name.  If @Nothing@, use the full graph.
           -> [SCC ModSummary]
@@ -1721,10 +1708,9 @@ topSortModuleGraph
 --              the a source-import of Foo is an import of Foo
 --              The resulting graph has no hi-boot nodes, but can be cyclic
 
-topSortModuleGraph drop_hs_boot_nodes module_graph mb_root_mod
+topSortModuleGraph drop_hs_boot_nodes summaries mb_root_mod
   = map (fmap summaryNodeSummary) $ stronglyConnCompG initial_graph
   where
-    summaries = mgModSummaries module_graph
     -- stronglyConnCompG flips the original order, so if we reverse
     -- the summaries we get a stable topological sort.
     (graph, lookup_node) =