Torsten Schmits pushed to branch wip/torsten.schmits/mwb-26-07/abstract-linkables at Glasgow Haskell Compiler / GHC Commits: 8cd52731 by Torsten Schmits at 2026-08-10T16:30:16+02:00 Split `getLinkDeps` and abstract over the interface This allows API clients to customize bytecode loading to implement on-demand compilation of interface core bindings. - - - - - 43fc929d by Torsten Schmits at 2026-08-10T16:30:16+02:00 Make extra_decls lazy when loading from Binary This is a backport. - - - - - 6 changed files: - compiler/GHC/Driver/Env/Types.hs - compiler/GHC/Driver/Main.hs - compiler/GHC/Linker/Deps.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Linker/Types.hs - compiler/GHC/Unit/Module/ModIface.hs Changes: ===================================== compiler/GHC/Driver/Env/Types.hs ===================================== @@ -29,6 +29,7 @@ import Control.Monad.Trans.Reader import Control.Monad.Trans.State import Data.IORef import GHC.Driver.Env.KnotVars +import GHC.Linker.Types (LoaderState, Linkables) -- | The Hsc monad: Passing an environment and diagnostic state newtype Hsc a = Hsc (HscEnv -> Messages GhcMessage -> IO (a, Messages GhcMessage)) @@ -44,7 +45,6 @@ instance ContainsDynFlags HscEnv where instance HasLogger Hsc where getLogger = Hsc $ \e w -> return (hsc_logger e, w) - -- | HscEnv is like 'GHC.Driver.Monad.Session', except that some of the fields are immutable. -- An HscEnv is used to compile a single module from plain Haskell source -- code (after preprocessing) to either C, assembly or C--. It's also used @@ -87,6 +87,8 @@ data HscEnv -- ^ target code interpreter (if any) to use for TH and GHCi. -- See Note [Target code interpreter] + , hsc_linkables :: HscEnv -> LoaderState -> IO Linkables + , hsc_plugins :: !Plugins -- ^ Plugins ===================================== compiler/GHC/Driver/Main.hs ===================================== @@ -342,6 +342,7 @@ newHscEnvWithHUG top_dir top_dynflags cur_unit home_unit_graph = do , hsc_FC = fc_var , hsc_type_env_vars = emptyKnotVars , hsc_interp = Nothing + , hsc_linkables = linkablesDefault , hsc_unit_env = unit_env , hsc_plugins = emptyPlugins , hsc_hooks = emptyHooks @@ -2880,10 +2881,10 @@ jsCodeGen hsc_env srcspan i this_mod stg_binds_with_deps binding_id = do -- Take lock for the actual work. (dep_linkables, dep_units) <- modifyLoaderState interp $ \pls -> do - let link_opts = initLinkDepsOpts hsc_env -- Find what packages and linkables are required - deps <- getLinkDeps link_opts interp pls srcspan needed_mods + linkables <- hsc_linkables hsc_env hsc_env pls + deps <- linkablesGet linkables srcspan needed_mods -- We update the LinkerState even if the JS interpreter maintains its linker -- state independently to load new objects here. ===================================== compiler/GHC/Linker/Deps.hs ===================================== @@ -12,6 +12,11 @@ module GHC.Linker.Deps ( LinkDepsOpts (..) , LinkDeps (..) , getLinkDeps + , Linkables (..) + , LinkDep (..) + , LinkModule (..) + , resolveLinkDeps + , selectLinkDeps ) where @@ -42,16 +47,13 @@ import GHC.Unit.Module.Graph import GHC.Unit.Home.ModInfo import GHC.Iface.Errors.Types -import GHC.Iface.Errors.Ppr import GHC.Utils.Misc import GHC.Unit.Home -import qualified GHC.Unit.Home.Graph as HUG import GHC.Data.Maybe import Control.Applicative import Control.Monad.IO.Class (MonadIO (liftIO)) -import Control.Monad.Trans.Except (ExceptT, runExceptT, throwE) import Data.Foldable (traverse_) import qualified Data.Set as Set @@ -60,10 +62,6 @@ import Data.List (isSuffixOf) import System.FilePath import System.Directory import GHC.Utils.Logger (Logger) -import Control.Monad ((<$!>)) -import GHC.Driver.Env -import {-# SOURCE #-} GHC.Driver.Main -import Data.Time.Clock import GHC.Unit.Home.Graph @@ -86,13 +84,6 @@ data LinkDepsOpts = LinkDepsOpts , ldLogger :: !Logger } -data LinkDeps = LinkDeps - { ldNeededLinkables :: [Linkable] - , ldAllLinkables :: [Linkable] - , ldNeededUnits :: [UnitId] - , ldAllUnits :: UniqDSet UnitId - } - -- | Find all the packages and linkables that a set of modules depends on -- -- Return the module and package dependencies for the needed modules. @@ -108,14 +99,8 @@ getLinkDeps -> [Module] -- If you need these -> IO LinkDeps -- ... then link these first getLinkDeps opts interp pls span mods = do - -- The interpreter and dynamic linker can only handle object code built - -- the "normal" way, i.e. no non-std ways like profiling or ticky-ticky. - -- So here we check the build tag: if we're building a non-standard way - -- then we need to find & link object files built the "normal" way. - maybe_normal_osuf <- checkNonStdWay opts interp span - - withTiming (ldLogger opts) (text "getLinkDeps" <+> brackets (ppr span)) (const ()) $ - get_link_deps opts pls maybe_normal_osuf span mods + linkables <- resolveLinkDeps opts pls span mods + selectLinkDeps opts interp span linkables -- | Determine which parts of a module and its dependencies should be linked -- when resolving external dependencies. @@ -180,48 +165,31 @@ instance Outputable LinkModule where LinkObjectModule mod _ -> ppr mod LinkByteCodeModule mod _ -> ppr mod <+> brackets (text "BC") --- | Compute the linkables for the given module set's dependencies. --- --- Home modules in make mode are treated separately in a preprocessing step, --- then all the remaining external deps are processed for both modes. --- If bytecode is available, transitive external deps are included, otherwise --- the module's library is linked and processing stops. --- --- The results are split into sets of needed/loaded modules/packages. -get_link_deps - :: LinkDepsOpts - -> LoaderState - -> Maybe FilePath -- replace object suffixes? - -> SrcSpan - -> [Module] - -> IO LinkDeps -get_link_deps opts pls maybe_normal_osuf span mods = do - (link_deps_home, module_deps_external) <- separate_home_deps - link_deps_external <- external_deps opts module_deps_external - let (loaded_modules, needed_modules, ldAllUnits, ldNeededUnits) = - classify_deps pls link_deps_home link_deps_external - ldNeededLinkables <- mapM module_linkable needed_modules - pure LinkDeps { - ldNeededLinkables, - ldAllLinkables = loaded_modules ++ ldNeededLinkables, - ldNeededUnits, - ldAllUnits - } +resolveLinkDeps :: + LinkDepsOpts -> + LoaderState -> + SrcSpan -> + [Module] -> + IO ([Linkable], [LinkModule], UniqDSet UnitId, [UnitId]) +resolveLinkDeps opts pls span mods = + withTiming (ldLogger opts) (text "getLinkDeps" <+> brackets (ppr span)) (const ()) $ do + (link_deps_home, module_deps_external) <- separate_home_deps + link_deps_external <- external_deps opts module_deps_external + pure (classify_deps pls link_deps_home link_deps_external) where mod_graph = ldModuleGraph opts unit_env = ldUnitEnv opts noninteractive = filterOut isInteractiveModule mods - -- Preprocess the dependencies in make mode to remove all home modules, - -- since the transitive dependency closure is already cached for those in - -- the HUG (see MultiLayerModulesTH_* tests for the performance impact). + -- Preprocess the dependencies to remove all home modules, since the + -- transitive dependency closure is already cached for those in the HUG + -- (see MultiLayerModulesTH_* tests for the performance impact). -- - -- Returns the remaining, external, dependencies on the right, which is the - -- entire set for oneshot mode. - separate_home_deps = - if ldOneShotMode opts - then pure ([], LinkExternal LinkAllDeps <$!> noninteractive) - else make_deps + -- Returns the remaining, external, dependencies on the right. + -- This function only supports make mode; oneshot mode (in which the + -- entire dependency set would be treated as external) is not used by + -- this worker and is not supported here. + separate_home_deps = make_deps make_deps = do (dep_ext, mmods) <- unzip <$> mapM get_mod_info all_home_mods @@ -265,6 +233,22 @@ get_link_deps opts pls maybe_normal_osuf span mods = do Nothing -> throwProgramError opts $ text "getLinkDeps: Home module not loaded" <+> ppr (gwib_mod gwib) <+> ppr uid +select_link_deps + :: LinkDepsOpts + -> Maybe FilePath -- replace object suffixes? + -> SrcSpan + -> ([Linkable], [LinkModule], UniqDSet UnitId, [UnitId]) + -> IO LinkDeps +select_link_deps opts maybe_normal_osuf span (loaded_modules, needed_modules, ldAllUnits, ldNeededUnits) = do + ldNeededLinkables <- mapM module_linkable needed_modules + pure LinkDeps { + ldNeededLinkables, + ldAllLinkables = loaded_modules ++ ldNeededLinkables, + ldNeededUnits, + ldAllUnits + } + where + no_obj :: Outputable a => a -> IO b no_obj mod = dieWith opts span $ text "cannot find object file for module" <+> @@ -321,6 +305,20 @@ get_link_deps opts pls maybe_normal_osuf span mods = do CoreBindings WholeCoreBindings {wcb_module} -> pprPanic "Unhydrated core bindings" (ppr wcb_module) +selectLinkDeps + :: LinkDepsOpts + -> Interp + -> SrcSpan -- for error messages + -> ([Linkable], [LinkModule], UniqDSet UnitId, [UnitId]) + -> IO LinkDeps -- ... then link these first +selectLinkDeps opts interp span linkables = do + -- The interpreter and dynamic linker can only handle object code built + -- the "normal" way, i.e. no non-std ways like profiling or ticky-ticky. + -- So here we check the build tag: if we're building a non-standard way + -- then we need to find & link object files built the "normal" way. + maybe_normal_osuf <- checkNonStdWay opts interp span + select_link_deps opts maybe_normal_osuf span linkables + data LinkDep = LinkModules !(UniqDFM ModuleName LinkModule) | @@ -331,11 +329,6 @@ instance Outputable LinkDep where LinkModules mods -> text "modules:" <+> ppr (eltsUDFM mods) LinkLibrary uid -> text "library:" <+> ppr uid -data OneshotError = - NoInterface !MissingInterfaceError - | - LinkBootModule !Module - -- | Compute the transitive dependency closure of the given modules. -- -- Used for all oneshot mode dependencies and for external dependencies of home @@ -346,21 +339,13 @@ external_deps :: [LinkExternal] -> IO [LinkDep] external_deps opts mods = - runExceptT (external_deps_loop opts mods emptyUDFM) >>= \case - Right a -> pure (eltsUDFM a) - Left err -> throwProgramError opts (message err) - where - message = \case - NoInterface err -> - missingInterfaceErrorDiagnostic (ldMsgOpts opts) err - LinkBootModule mod -> - link_boot_mod_error mod + eltsUDFM <$> external_deps_loop opts mods emptyUDFM external_deps_loop :: LinkDepsOpts -> [LinkExternal] -> UniqDFM UnitId LinkDep -> - ExceptT OneshotError IO (UniqDFM UnitId LinkDep) + IO (UniqDFM UnitId LinkDep) external_deps_loop _ [] acc = pure acc external_deps_loop opts (job@LinkExternal {le_module = mod, ..} : mods) acc = do @@ -386,8 +371,7 @@ external_deps_loop opts (job@LinkExternal {le_module = mod, ..} : mods) acc = do -- link an object file (which happens for home unit modules, since those -- have no libraries). process_module = \case - LinkAllDeps | is_home || package_bc -> try_iface - | otherwise -> add_library + LinkAllDeps -> add_library -- @LinkOnlyPackages@ is used for make mode home modules, so all imports -- that are not external are already processed otherwise. @@ -407,45 +391,9 @@ external_deps_loop opts (job@LinkExternal {le_module = mod, ..} : mods) acc = do | otherwise = False - -- Load the iface and attempt to get bytecode from Core bindings. - try_iface = - liftIO (ldLoadIface opts load_reason mod) >>= \case - Failed err -> throwE (NoInterface err) - Succeeded (iface, loc) -> do - mb_load_bc <- liftIO (ldLoadByteCode opts (mi_module iface)) - with_iface iface loc mb_load_bc - - -- Decide how to link this module. - -- If bytecode or an object file is available, use those in that order. - -- Otherwise fall back to linking a library. - with_iface iface loc mb_load_bc - | IsBoot <- mi_boot iface - = throwE (LinkBootModule mod) - - | ldUseByteCode opts - , is_home || package_bc - , Just load_bc <- mb_load_bc - = add_module iface (LinkByteCodeModule mod load_bc) "bytecode" - - | is_home - = add_module iface (LinkObjectModule mod loc) "object" - - | otherwise - = add_library - add_library = pure (addToUDFM acc mod_unit_id (LinkLibrary mod_unit_id), [], Just "library") - add_module iface lmod action = - with_deps with_mod iface True action - where - with_mod = alterUDFM (add_package_module lmod) acc mod_unit_id - - add_package_module lmod = \case - Just (LinkLibrary u) -> Just (LinkLibrary u) - Just (LinkModules old) -> Just (LinkModules (addToUDFM old mod_name lmod)) - Nothing -> Just (LinkModules (unitUDFM mod_name lmod)) - with_deps acc iface local action = pure (addListToUDFM acc link, new_local ++ new_package, Just action) where @@ -458,26 +406,17 @@ external_deps_loop opts (job@LinkExternal {le_module = mod, ..} : mods) acc = do | (_, GWIB m _) <- Set.toList (dep_direct_mods (mi_deps iface)) ] - -- If bytecode linking of external dependencies is enabled, add them to the - -- jobs passed to the next iteration of 'external_deps_loop'. - -- Otherwise, link all package deps as libraries. - package_deps iface - | package_bc - = ([], [LinkExternal LinkAllDeps usg_mod | UsagePackageModule {usg_mod} <- mi_usages iface]) - | otherwise - = ([(u, LinkLibrary u) | u <- Set.toList (dep_direct_pkgs (mi_deps iface))], []) - - load_reason = - text "need to link module" <+> ppr mod <+> - text "due to use of Template Haskell" - - package_bc = ldPkgByteCode opts - - -- In multiple home unit mode, this only considers modules from the same - -- unit as the splice's module to be eligible for linking bytecode when - -- @-fpackage-db-byte-code@ is off. - -- For make mode, this is irrelevant, since any bytecode from the HUG is - -- obtained directly, not going through 'external_deps'. + -- External package dependencies are always linked as libraries; this + -- worker does not support traversing external package modules for + -- bytecode ("-fpackage-db-byte-code"). + package_deps iface = + ([(u, LinkLibrary u) | u <- Set.toList (dep_direct_pkgs (mi_deps iface))], []) + + -- Considers only modules from the same unit as the splice's module to be + -- eligible for linking bytecode. + -- For make mode, this is irrelevant for home modules in general, since any + -- bytecode from the HUG is obtained directly, not going through + -- 'external_deps'. is_home | Just home <- ue_homeUnit (ldUnitEnv opts) = homeUnitAsUnit home == mod_unit @@ -489,11 +428,6 @@ external_deps_loop opts (job@LinkExternal {le_module = mod, ..} : mods) acc = do mod_unit_id = moduleUnitId mod mod_unit = moduleUnit mod -link_boot_mod_error :: Module -> SDoc -link_boot_mod_error mod = - text "module" <+> ppr mod <+> - text "cannot be linked; it is only available as a boot module" - -- | Split link dependencies into the sets of modules and packages that have -- been linked previously and those that need to be linked now by checking for -- their presence in the 'LoaderState': ===================================== compiler/GHC/Linker/Loader.hs ===================================== @@ -32,6 +32,7 @@ module GHC.Linker.Loader , rmDupLinkables , modifyLoaderState , initLinkDepsOpts + , linkablesDefault ) where @@ -97,7 +98,6 @@ import Control.Monad import qualified Data.Set as Set import Data.Char (isSpace) import Data.Functor ((<&>)) -import qualified Data.Foldable as Foldable import Data.IORef import Data.List (intercalate, isPrefixOf, nub, partition) import Data.Maybe @@ -115,7 +115,7 @@ import System.Win32.Info (getSystemDirectory) #endif import GHC.Utils.Exception -import GHC.Unit.Home.Graph (lookupHug, unitEnv_foldWithKey) +import GHC.Unit.Home.Graph (unitEnv_foldWithKey) -- Note [Linkers and loaders] -- ~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -231,10 +231,10 @@ loadDependencies -> IO (LoaderState, SuccessFlag, [Linkable], PkgsLoaded) -- ^ returns the set of linkables required -- When called, the loader state must have been initialized (see `initLoaderState`) loadDependencies interp hsc_env pls span needed_mods = do - let opts = initLinkDepsOpts hsc_env + linkables <- hsc_linkables hsc_env hsc_env pls -- Find what packages and linkables are required - deps <- getLinkDeps opts interp pls span needed_mods + deps <- linkablesGet linkables span needed_mods let this_pkgs_needed = ldAllUnits deps @@ -683,6 +683,17 @@ initLinkDepsOpts hsc_env = opts EPS {eps_iface_bytecode} <- hscEPS hsc_env pure (lookupModuleEnv eps_iface_bytecode mod) +linkablesDefault :: + HscEnv -> + LoaderState -> + IO Linkables +linkablesDefault hsc_env pls = + pure Linkables { + linkablesResolve = resolveLinkDeps opts pls, + linkablesSelect = selectLinkDeps opts (hscInterp hsc_env) + } + where + opts = initLinkDepsOpts hsc_env {- ********************************************************************** ===================================== compiler/GHC/Linker/Types.hs ===================================== @@ -1,5 +1,6 @@ {-# LANGUAGE TypeApplications #-} {-# LANGUAGE LambdaCase #-} +{-# LANGUAGE RecordWildCards #-} ----------------------------------------------------------------------------- -- @@ -45,6 +46,9 @@ module GHC.Linker.Types , linkableFilterByteCode , linkableFilterNative , partitionLinkables + , LinkDeps (..) + , Linkables (..) + , linkablesGet ) where @@ -57,6 +61,7 @@ import GHCi.Message ( LoadedDLL ) import GHC.Types.Name.Env ( NameEnv, emptyNameEnv, extendNameEnvList, filterNameEnv ) import GHC.Types.Name ( Name ) import GHC.Types.SptEntry +import GHC.Types.SrcLoc (SrcSpan) import GHC.Utils.Outputable @@ -477,3 +482,21 @@ instance Outputable LibrarySpec where ppr (DLL s) = text "DLL" <+> text s ppr (DLLPath f) = text "DLLPath" <+> text f ppr (Framework s) = text "Framework" <+> text s + +data LinkDeps = + LinkDeps { + ldNeededLinkables :: [Linkable], + ldAllLinkables :: [Linkable], + ldNeededUnits :: [UnitId], + ldAllUnits :: UniqDSet UnitId + } + +data Linkables where + Linkables :: { + linkablesResolve :: SrcSpan -> [Module] -> IO a, + linkablesSelect :: SrcSpan -> a -> IO LinkDeps + } -> Linkables + +linkablesGet :: Linkables -> SrcSpan -> [Module] -> IO LinkDeps +linkablesGet Linkables {..} span mods = + linkablesSelect span =<< linkablesResolve span mods ===================================== compiler/GHC/Unit/Module/ModIface.hs ===================================== @@ -503,7 +503,7 @@ instance Binary ModIface where lazyPut bh warns lazyPut bh anns put_ bh decls - put_ bh extra_decls + lazyPut bh extra_decls put_ bh foreign_ put_ bh insts put_ bh fam_insts @@ -536,7 +536,7 @@ instance Binary ModIface where warns <- {-# SCC "bin_warns" #-} lazyGet bh anns <- {-# SCC "bin_anns" #-} lazyGet bh decls <- {-# SCC "bin_tycldecls" #-} get bh - extra_decls <- get bh + extra_decls <- lazyGet bh foreign_ <- get bh insts <- {-# SCC "bin_insts" #-} get bh fam_insts <- {-# SCC "bin_fam_insts" #-} get bh View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/de0c838cf53fa809bfb45a63a24ee1b... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/de0c838cf53fa809bfb45a63a24ee1b... 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