Wolfgang Jeltsch pushed to branch wip/jeltsch/improve-closure-property-check at Glasgow Haskell Compiler / GHC Commits: 755cf854 by Wolfgang Jeltsch at 2026-08-25T14:01:09+03:00 Re-implement the home unit closure check Resolves #27051. - - - - - 4 changed files: - compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/Errors/Ppr.hs - compiler/GHC/Driver/Errors/Types.hs - compiler/GHC/Unit/Env.hs Changes: ===================================== compiler/GHC/Driver/Downsweep.hs ===================================== @@ -54,8 +54,8 @@ import GHC.Runtime.Context import Language.Haskell.Syntax.ImpExp import GHC.Types.UnresolvedImport -import GHC.Data.Graph.Directed import GHC.Data.FastString +import GHC.Data.ShortText (ShortText) import GHC.Data.Maybe ( expectJust ) import qualified GHC.Data.Maybe as M import GHC.Data.OsPath ( OsPath, unsafeEncodeUtf ) @@ -71,12 +71,14 @@ import GHC.Utils.Logger import GHC.Utils.Fingerprint import GHC.Utils.TmpFs import GHC.Utils.Constants +import GHC.Utils.Monad.State.Strict import GHC.Types.Error import GHC.Types.Target import GHC.Types.SourceFile import GHC.Types.SourceError import GHC.Types.SrcLoc +import GHC.Types.Unique.Set import GHC.Types.Unique.Map import GHC.Types.PkgQual import GHC.Types.Basic @@ -93,7 +95,9 @@ import qualified GHC.Unit.Home.Graph as HUG import GHC.Unit.Module.Stage import Data.Either ( partitionEithers, lefts ) +import Data.Map (Map) import qualified Data.Map as Map +import Data.Set (Set) import qualified Data.Set as Set import Control.Concurrent.MVar @@ -101,7 +105,7 @@ import Control.Monad import Control.Monad.Trans.Except ( ExceptT(..), runExceptT, throwE ) import qualified Control.Monad.Catch as MC import Data.Maybe -import Data.List (partition) +import Data.List (sort, partition) import Data.Time import Data.List (unfoldr) import Data.Bifunctor (first, bimap) @@ -933,52 +937,85 @@ rootSummariesParallel n_jobs hsc_env diag_wrapper msg get_summary = do -- * Check/validate properties and error out -------------------------------------------------------------------------------- --- | This function checks then important property that if both p and q are home units --- then any dependency of p, which transitively depends on q is also a home unit. --- --- See Note [Multiple Home Units], section 'Closure Property'. -checkHomeUnitsClosed :: UnitEnv -> [DriverMessages] -checkHomeUnitsClosed ue - | Set.null bad_unit_ids = [] - | otherwise = [singleMessage $ mkPlainErrorMsgEnvelope rootLoc $ DriverHomePackagesNotClosed (Set.toList bad_unit_ids)] +-- | Checks whether the given unit environment has the closure property. See +-- the section “Closure Property” in @Note [Multiple Home Units]@. +checkHomeUnitsClosed :: UnitEnv -> [DriverMessages] +checkHomeUnitsClosed unit_env + | null offenders = [] + | otherwise = [ + singleMessage $ + mkPlainErrorMsgEnvelope error_source_span $ + DriverHomePackagesNotClosed (sort offenders) + ] where - home_id_set = HUG.allUnits $ ue_home_unit_graph ue - bad_unit_ids = upwards_closure Set.\\ home_id_set {- Remove all home units reached, keep only bad nodes -} - rootLoc = mkGeneralSrcSpan (fsLit "<command line>") - downwards_closure :: Graph (Node UnitId UnitId) - downwards_closure = graphFromEdgedVerticesUniq graphNodes + home_unit_data :: [(UnitId, HomeUnitEnv)] + home_unit_data = HUG.unitEnv_assocs (ue_home_unit_graph unit_env) - inverse_closure = graphReachability $ transposeG downwards_closure + home_units :: UniqSet UnitId + home_units = mkUniqSet (map fst home_unit_data) - upwards_closure = Set.fromList $ map node_key $ allReachableMany inverse_closure [DigraphNode uid uid [] | uid <- Set.toList home_id_set] + offenders :: [(UnitId, UnitId)] + offenders + = evalState (collect (map (homeUnitEnv_units . snd) home_unit_data)) $ + Set.empty + where - all_unit_direct_deps :: UniqMap UnitId (Set.Set UnitId) - all_unit_direct_deps - = HUG.unitEnv_foldWithKey go emptyUniqMap $ ue_home_unit_graph ue + collect :: [UnitState] -> State (Set ShortText) [(UnitId, UnitId)] + collect [] + = pure [] + collect (current_unit_state : remaining_unit_states) + = (++) <$> collect_for_home_unit + (unitInfoMap current_unit_state) + (map (toUnitId . fst) $ explicitUnits $ current_unit_state) + <*> collect remaining_unit_states where - go rest this this_uis = - plusUniqMap_C Set.union - (addToUniqMap_C Set.union external_depends this (Set.fromList $ this_deps)) - rest - where - external_depends = mapUniqMap (Set.fromList . unitDepends) (unitInfoMap this_units) - this_units = homeUnitEnv_units this_uis - this_deps = [ toUnitId unit | (unit,Just _) <- explicitUnits this_units] - - graphNodes :: [Node UnitId UnitId] - graphNodes = go Set.empty home_id_set - where - go done todo - = case Set.minView todo of - Nothing -> [] - Just (uid, todo') - | Set.member uid done -> go done todo' - | otherwise -> case lookupUniqMap all_unit_direct_deps uid of - Nothing -> pprPanic "uid not found" (ppr (uid, all_unit_direct_deps)) - Just depends -> - let todo'' = (depends Set.\\ done) `Set.union` todo' - in DigraphNode uid uid (Set.toList depends) : go (Set.insert uid done) todo'' + + collect_for_home_unit :: UnitInfoMap + -> [UnitId] + -> State (Set ShortText) [(UnitId, UnitId)] + collect_for_home_unit _ [] + = return [] + collect_for_home_unit unit_info_map (current_unit : remaining_units) = do + let + + unit_info :: UnitInfo + unit_info + = fromMaybe (pprPanic unit_not_found_msg (ppr current_unit)) $ + lookupUniqMap unit_info_map current_unit + where + + unit_not_found_msg :: String + unit_not_found_msg = "Unit not found during closure property check" + + abi_hash :: ShortText + abi_hash = unitAbiHash unit_info + + has_been_processed <- gets (Set.member abi_hash) + if has_been_processed + then collect_for_home_unit unit_info_map remaining_units + else do + modify (Set.insert abi_hash) + let + + needed_units :: [UnitId] + needed_units = unitDepends unit_info + + current_offenders :: [(UnitId, UnitId)] + current_offenders + | current_unit `elementOfUniqSet` home_units + = [] + | otherwise + = map ((,) current_unit) $ + nonDetEltsUniqSet $ + mkUniqSet needed_units `intersectUniqSets` home_units + + remaining_offenders <- collect_for_home_unit unit_info_map $ + needed_units ++ remaining_units + return $ current_offenders ++ remaining_offenders + + error_source_span :: SrcSpan + error_source_span = mkGeneralSrcSpan (fsLit "<command line>") -------------------------------------------------------------------------------- -- * Enable Code Gen for Template Haskell @@ -1763,7 +1800,7 @@ data NodeRes v -- -- See also Note [Downsweep Control Flow and Caching] dfsBuild :: (Ord k, Monad m) - => Maybe (Map.Map k (NodeRes v)) + => Maybe (Map k (NodeRes v)) -- ^ Base map, existing results. We won't re-expand any of the nodes -- already present in this map. -> [n] @@ -1773,7 +1810,7 @@ dfsBuild :: (Ord k, Monad m) -> (n -> m (NodeRes (v,[n]))) -- ^ Expand this node into its payload result and into the list of -- children nodes to visit next. - -> m (Map.Map k (NodeRes v)) + -> m (Map k (NodeRes v)) -- ^ The result accumulates the payload of expanding the root nodes -- and all nodes transitively reachable from those roots. dfsBuild base_map roots key expand = go roots (fromMaybe Map.empty base_map) ===================================== compiler/GHC/Driver/Errors/Ppr.hs ===================================== @@ -235,10 +235,17 @@ instance Diagnostic DriverMessage where "but no output will be generated.") $$ (text "There is no module named" <+> quotes (ppr mod_name) <> text ".")) - DriverHomePackagesNotClosed needed_unit_ids - -> mkSimpleDecorated $ vcat ([text "Home units are not closed." - , text "It is necessary to also load the following units:" ] - ++ map (\uid -> text "-" <+> ppr uid) needed_unit_ids) + DriverHomePackagesNotClosed offending_dependencies + -> mkSimpleDecorated $ + hang (text "Some units are not loaded but depend on loaded units.") + 4 + (vcat (map pprDependency offending_dependencies)) + where + + pprDependency :: (UnitId, UnitId) -> SDoc + pprDependency (external_unit, home_unit) + = ppr external_unit <+> arrow <+> ppr home_unit + DriverInterfaceError reason -> diagnosticMessage (ifaceDiagnosticOpts opts) reason DriverInconsistentDynFlags msg ===================================== compiler/GHC/Driver/Errors/Types.hs ===================================== @@ -369,7 +369,7 @@ data DriverMessage where DriverRedirectedNoMain :: !ModuleName -> DriverMessage - DriverHomePackagesNotClosed :: ![UnitId] -> DriverMessage + DriverHomePackagesNotClosed :: ![(UnitId, UnitId)] -> DriverMessage DriverInterfaceError :: !IfaceMessage -> DriverMessage ===================================== compiler/GHC/Unit/Env.hs ===================================== @@ -443,13 +443,11 @@ The flow: Closure Property ---------------- -You must perform a clean cut of the dependency graph. - -> Any dependency which is not a home unit must not (transitively) depend on a home unit. - -For example, if you have three packages p, q and r, then if p depends on q which -depends on r then it is illegal to load both p and r as home units but not q, -because q is a dependency of the home unit p which depends on another home unit r. +A unit environment must have the closure property, which means that, whenever +some units @h₁@ and @h₂@ have been loaded as home units, @h₁@ does not directly +or indirectly depend on an external unit that directly or indirectly depends +on @h₂@. 'GHC.Driver.Downsweep.checkHomeUnitsClosed' checks whether a given unit +environment indeed has this property. Offsetting Paths ---------------- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/755cf854150d85be469d6ad0d14cc6b4... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/755cf854150d85be469d6ad0d14cc6b4... You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help