-- The transition from Int to Word64 for uniques makes functions slightly larger -- without this GHC option some optimizations fail to fire. -- See https://gitlab.haskell.org/ghc/ghc/-/merge_requests/10568#note_505751 {-# OPTIONS_GHC -fspec-constr-threshold=10000 #-} {-# LANGUAGE CPP #-} {-# LANGUAGE RecordWildCards #-} {-# LANGUAGE LambdaCase #-} module GHC.Linker.Deps ( LinkDepsOpts (..) , LinkDeps (..) , getLinkDeps ) where import GHC.Prelude import GHC.Platform.Ways import GHC.Runtime.Interpreter import GHC.Linker.Types import GHC.Types.SrcLoc import GHC.Types.Unique.DSet import GHC.Types.Unique.DFM import GHC.Utils.Outputable import GHC.Utils.Panic import GHC.Utils.Error import GHC.Unit.Env import GHC.Unit.Finder import GHC.Unit.Module import GHC.Unit.Module.WholeCoreBindings import GHC.Unit.Home.ModInfo import GHC.Iface.Errors.Types import GHC.Utils.Misc import qualified GHC.Unit.Home.Graph as HUG import GHC.Data.Maybe import Control.Applicative import Data.List (isSuffixOf) import System.FilePath import System.Directory data LinkDepsOpts = LinkDepsOpts { ldObjSuffix :: !String -- ^ Suffix of .o files , ldForceDyn :: !Bool -- ^ Always use .dyn_o? , ldUnitEnv :: !UnitEnv , ldPprOpts :: !SDocContext -- ^ Rendering options for error messages , ldUseByteCode :: !Bool -- ^ Use bytecode rather than objects , ldMsgOpts :: !(DiagnosticOpts IfaceMessage) -- ^ Options for diagnostics , ldWays :: !Ways -- ^ Enabled ways , ldFinderCache :: !FinderCache , ldFinderOpts :: !FinderOpts , ldLoadByteCode :: !(Module -> IO (Maybe Linkable)) , ldGetDependencies :: !([Module] -> IO ([Module], UniqDSet UnitId)) } data LinkDeps = LinkDeps { ldNeededLinkables :: [Linkable] , ldAllLinkables :: [Linkable] , ldUnits :: [UnitId] , ldNeededUnits :: 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. -- See Note [Object File Dependencies] -- -- Fails with an IO exception if it can't find enough files -- getLinkDeps :: LinkDepsOpts -> Interp -> LoaderState -> SrcSpan -- for error messages -> [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 get_link_deps opts pls maybe_normal_osuf span mods 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 -- Three step process: -- 1. Find the dependent home-pkg-modules/packages from each iface -- (omitting modules from the interactive package, which is already linked) (mods_s, pkgs_s) <- ldGetDependencies opts relevant_mods let -- 2. Exclude ones already linked -- Main reason: avoid findModule calls in get_linkable (mods_needed, links_got) = partitionWith split_mods mods_s pkgs_needed = eltsUDFM $ getUniqDSet pkgs_s `minusUDFM` pkgs_loaded pls split_mods mod = let is_linked = lookupModuleEnv (objs_loaded pls) mod <|> lookupModuleEnv (bcos_loaded pls) mod in case is_linked of Just linkable -> Right linkable Nothing -> Left mod -- 3. For each dependent module, find its linkable -- This will either be in the HPT or (in the case of one-shot -- compilation) we may need to use maybe_getFileLinkable lnks_needed <- mapM (get_linkable (ldObjSuffix opts)) mods_needed return $ LinkDeps { ldNeededLinkables = lnks_needed , ldAllLinkables = links_got ++ lnks_needed , ldUnits = pkgs_needed , ldNeededUnits = pkgs_s } where unit_env = ldUnitEnv opts relevant_mods = filterOut isInteractiveModule mods no_obj :: Outputable a => a -> IO b no_obj mod = dieWith opts span $ text "cannot find object file for module " <> quotes (ppr mod) $$ while_linking_expr while_linking_expr = text "while linking an interpreted expression" -- See Note [Using Byte Code rather than Object Code for Template Haskell] homeModLinkable :: HomeModInfo -> Maybe Linkable homeModLinkable hmi = if ldUseByteCode opts then homeModInfoByteCode hmi <|> homeModInfoObject hmi else homeModInfoObject hmi <|> homeModInfoByteCode hmi get_linkable osuf mod -- A home-package module = HUG.lookupHugByModule mod (ue_home_unit_graph unit_env) >>= \case Just mod_info -> adjust_linkable (expectJust (homeModLinkable mod_info)) Nothing -> do -- It's not in the HPT because we are in one shot mode, -- so use the Finder to get a ModLocation... case ue_homeUnit unit_env of Nothing -> no_obj mod Just home_unit -> do from_bc <- ldLoadByteCode opts mod maybe (fallback_no_bytecode home_unit mod) pure from_bc where fallback_no_bytecode home_unit mod = do let fc = ldFinderCache opts let fopts = ldFinderOpts opts mb_stuff <- findHomeModule fc fopts home_unit (moduleName mod) case mb_stuff of Found loc _ -> do mb_lnk <- findObjectLinkableMaybe mod loc case mb_lnk of Nothing -> no_obj mod Just lnk -> adjust_linkable lnk _ -> no_obj (moduleName mod) adjust_linkable lnk | Just new_osuf <- maybe_normal_osuf = do new_parts <- mapM (adjust_part new_osuf) (linkableParts lnk) return lnk{ linkableParts=new_parts } | otherwise = return lnk adjust_part new_osuf part = case part of DotO file ModuleObject -> do massert (osuf `isSuffixOf` file) let file_base = fromJust (stripExtension osuf file) new_file = file_base <.> new_osuf ok <- doesFileExist new_file if (not ok) then dieWith opts span $ text "cannot find object file " <> quotes (text new_file) $$ while_linking_expr else return (DotO new_file ModuleObject) DotO file ForeignObject -> pure (DotO file ForeignObject) DotA fp -> panic ("adjust_ul DotA " ++ show fp) DotDLL fp -> panic ("adjust_ul DotDLL " ++ show fp) BCOs {} -> pure part LazyBCOs{} -> pure part CoreBindings WholeCoreBindings {wcb_module} -> pprPanic "Unhydrated core bindings" (ppr wcb_module) {- Note [Using Byte Code rather than Object Code for Template Haskell] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The `-fprefer-byte-code` flag allows a user to specify that they want to use byte code (if available) rather than object code for home module dependencies when executing Template Haskell splices. Why might you want to use byte code rather than object code? * Producing object code is much slower than producing byte code (for example if you're using -fno-code) * Linking many large object files, which happens once per splice, is quite expensive. (#21700) So we allow the user to choose to use byte code rather than object files if they want to avoid these two pitfalls. When using `-fprefer-byte-code` you have to arrange to have the byte code available. In normal --make mode it will not be produced unless you enable `-fbyte-code-and-object-code`. See Note [Home module build products] for some more information about that. The only other place where the flag is consulted is when enabling code generation with `-fno-code`, which does so to anticipate what decision we will make at the splice point about what we would prefer. -} dieWith :: LinkDepsOpts -> SrcSpan -> SDoc -> IO a dieWith opts span msg = throwProgramError opts (mkLocMessage MCFatal span msg) throwProgramError :: LinkDepsOpts -> SDoc -> IO a throwProgramError opts doc = throwGhcExceptionIO (ProgramError (renderWithContext (ldPprOpts opts) doc)) checkNonStdWay :: LinkDepsOpts -> Interp -> SrcSpan -> IO (Maybe FilePath) checkNonStdWay _opts interp _srcspan -- On some targets (e.g. wasm) the RTS linker only supports loading -- dynamic code, in which case we need to ensure the .dyn_o object -- is picked (instead of .o which is also present because of -- -dynamic-too) | ldForceDyn _opts = do let target_ways = fullWays $ ldWays _opts pure $ if target_ways `hasWay` WayDyn then Nothing else Just $ waysTag (WayDyn `addWay` target_ways) ++ "_o" | ExternalInterp {} <- interpInstance interp = return Nothing -- with -fexternal-interpreter we load the .o files, whatever way -- they were built. If they were built for a non-std way, then -- we will use the appropriate variant of the iserv binary to load them. -- #if-guard the following equations otherwise the pattern match checker will -- complain that they are redundant. #if defined(HAVE_INTERNAL_INTERPRETER) checkNonStdWay opts _interp srcspan | hostFullWays == targetFullWays = return Nothing -- Only if we are compiling with the same ways as GHC is built -- with, can we dynamically load those object files. (see #3604) | ldObjSuffix opts == normalObjectSuffix && not (null targetFullWays) = failNonStd opts srcspan | otherwise = return (Just (hostWayTag ++ "o")) where targetFullWays = fullWays (ldWays opts) hostWayTag = case waysTag hostFullWays of "" -> "" tag -> tag ++ "_" normalObjectSuffix :: String normalObjectSuffix = "o" data Way' = Normal | Prof | Dyn | ProfDyn failNonStd :: LinkDepsOpts -> SrcSpan -> IO (Maybe FilePath) failNonStd opts srcspan = dieWith opts srcspan $ text "Cannot load" <+> pprWay' compWay <+> text "objects when GHC is built" <+> pprWay' ghciWay $$ text "To fix this, either:" $$ text " (1) Use -fexternal-interpreter, or" $$ buildTwiceMsg where compWay | ldWays opts `hasWay` WayDyn && ldWays opts `hasWay` WayProf = ProfDyn | ldWays opts `hasWay` WayDyn = Dyn | ldWays opts `hasWay` WayProf = Prof | otherwise = Normal ghciWay | hostIsDynamic && hostIsProfiled = ProfDyn | hostIsDynamic = Dyn | hostIsProfiled = Prof | otherwise = Normal buildTwiceMsg = case (ghciWay, compWay) of (Normal, Dyn) -> dynamicTooMsg (Dyn, Normal) -> dynamicTooMsg _ -> text " (2) Build the program twice: once" <+> pprWay' ghciWay <> text ", and then" $$ text " " <> pprWay' compWay <+> text "using -osuf to set a different object file suffix." dynamicTooMsg = text " (2) Use -dynamic-too," <+> text "and use -osuf and -dynosuf to set object file suffixes as needed." pprWay' :: Way' -> SDoc pprWay' way = text $ case way of Normal -> "the normal way" Prof -> "with -prof" Dyn -> "with -dynamic" ProfDyn -> "with -prof and -dynamic" #endif