X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fmain%2FTidyPgm.lhs;h=82021b813384a30bf36c0c73318bd627b72cfe74;hp=e3279965fac8cc2edc70d1843e28e91e93b11de5;hb=e79c9ce01d0ce4412bd4bcd99c8c728a6a2ec569;hpb=7379e82aafc7d0c1b839a13a20d52babeafed023 diff --git a/compiler/main/TidyPgm.lhs b/compiler/main/TidyPgm.lhs index e327996..82021b8 100644 --- a/compiler/main/TidyPgm.lhs +++ b/compiler/main/TidyPgm.lhs @@ -22,6 +22,7 @@ import VarEnv import VarSet import Var import Id +import Class import IdInfo import InstEnv import NewDemand @@ -34,21 +35,17 @@ import OccName import TcType import DataCon import TyCon -import Class import Module import HscTypes import Maybes import ErrUtils import UniqSupply import Outputable -import FastTypes hiding (fastOr) +import FastBool hiding ( fastOr ) import Data.List ( partition ) import Data.Maybe ( isJust ) import Data.IORef ( IORef, readIORef, writeIORef ) - -_dummy :: FS.FastString -_dummy = FSLIT("") \end{code} @@ -138,28 +135,42 @@ mkBootModDetails hsc_env exports type_env insts fam_insts ; showPass dflags "Tidy [hoot] type env" ; let { insts' = tidyInstances tidyExternalId insts - ; type_env1 = filterNameEnv (not . isWiredInThing) type_env - ; type_env2 = mapNameEnv tidyBootThing type_env1 - ; type_env' = extendTypeEnvWithIds type_env2 - (map instanceDFunId insts') + ; dfun_ids = map instanceDFunId insts' + ; type_env1 = tidyBootTypeEnv (availsToNameSet exports) type_env + ; type_env' = extendTypeEnvWithIds type_env1 dfun_ids } ; return (ModDetails { md_types = type_env' , md_insts = insts' , md_fam_insts = fam_insts , md_rules = [] + , md_anns = [] , md_exports = exports , md_vect_info = noVectInfo }) } where -isWiredInThing :: TyThing -> Bool -isWiredInThing thing = isWiredInName (getName thing) +tidyBootTypeEnv :: NameSet -> TypeEnv -> TypeEnv +tidyBootTypeEnv exports type_env + = tidyTypeEnv True False exports type_env final_ids + where + -- Find the LocalIds in the type env that are exported + -- Make them into GlobalIds, and tidy their types + -- + -- It's very important to remove the non-exported ones + -- because we don't tidy the OccNames, and if we don't remove + -- the non-exported ones we'll get many things with the + -- same name in the interface file, giving chaos. + final_ids = [ tidyExternalId id + | id <- typeEnvIds type_env + , isLocalId id + , keep_it id ] + + -- default methods have their export flag set, but everything + -- else doesn't (yet), because this is pre-desugaring, so we + -- must test both. + keep_it id = isExportedId id || idName id `elemNameSet` exports -tidyBootThing :: TyThing -> TyThing --- Just externalise the Ids; keep everything -tidyBootThing (AnId id) | isLocalId id = AnId (tidyExternalId id) -tidyBootThing thing = thing tidyExternalId :: Id -> Id -- Takes an LocalId with an External Name, @@ -167,7 +178,7 @@ tidyExternalId :: Id -> Id -- (NB: vanillaIdInfo makes a conservative assumption about Caf-hood.) tidyExternalId id = ASSERT2( isLocalId id && isExternalName (idName id), ppr id ) - mkVanillaGlobal (idName id) (tidyTopType (idType id)) vanillaIdInfo + mkVanillaGlobal (idName id) (tidyTopType (idType id)) \end{code} @@ -244,14 +255,14 @@ RHSs, so that they print nicely in interfaces. \begin{code} tidyProgram :: HscEnv -> ModGuts -> IO (CgGuts, ModDetails) -tidyProgram hsc_env - (ModGuts { mg_module = mod, mg_exports = exports, +tidyProgram hsc_env (ModGuts { mg_module = mod, mg_exports = exports, mg_types = type_env, mg_insts = insts, mg_fam_insts = fam_insts, mg_binds = binds, mg_rules = imp_rules, mg_vect_info = vect_info, mg_dir_imps = dir_imps, + mg_anns = anns, mg_deps = deps, mg_foreign = foreign_stubs, mg_hpc_info = hpc_info, @@ -261,6 +272,7 @@ tidyProgram hsc_env ; showPass dflags "Tidy Core" ; let { omit_prags = dopt Opt_OmitInterfacePragmas dflags + ; th = dopt Opt_TemplateHaskell dflags ; ext_ids = findExternalIds omit_prags binds ; ext_rules | omit_prags = [] @@ -277,8 +289,10 @@ tidyProgram hsc_env binds ; let { export_set = availsToNameSet exports - ; tidy_type_env = tidyTypeEnv omit_prags export_set type_env - tidy_binds + ; final_ids = [ id | id <- bindersOfBinds tidy_binds, + isExternalName (idName id)] + ; tidy_type_env = tidyTypeEnv omit_prags th export_set + type_env final_ids ; tidy_insts = tidyInstances (lookup_dfun tidy_type_env) insts -- A DFunId will have a binding in tidy_binds, and so -- will now be in final_env, replete with IdInfo @@ -291,8 +305,10 @@ tidyProgram hsc_env -- and indeed it does, but if omit_prags is on, ext_rules is -- empty - ; implicit_binds = getImplicitBinds type_env - ; all_tidy_binds = implicit_binds ++ tidy_binds + -- See Note [Injecting implicit bindings] + ; implicit_binds = getImplicitBinds type_env + ; all_tidy_binds = implicit_binds ++ tidy_binds + ; alg_tycons = filter isAlgTyCon (typeEnvTyCons type_env) } @@ -301,7 +317,7 @@ tidyProgram hsc_env "Tidy Core Rules" (pprRules tidy_rules) - ; let dir_imp_mods = map fst (moduleEnvElts dir_imps) + ; let dir_imp_mods = moduleEnvKeys dir_imps ; return (CgGuts { cg_module = mod, cg_tycons = alg_tycons, @@ -317,7 +333,8 @@ tidyProgram hsc_env md_insts = tidy_insts, md_fam_insts = fam_insts, md_exports = exports, - md_vect_info = vect_info -- is already tidy + md_anns = anns, -- are already tidy + md_vect_info = vect_info -- }) } @@ -327,7 +344,10 @@ lookup_dfun type_env dfun_id Just (AnId dfun_id') -> dfun_id' _other -> pprPanic "lookup_dfun" (ppr dfun_id) -tidyTypeEnv :: Bool -> NameSet -> TypeEnv -> [CoreBind] -> TypeEnv +-------------------------- +tidyTypeEnv :: Bool -- Compiling without -O, so omit prags + -> Bool -- Template Haskell is on + -> NameSet -> TypeEnv -> [Id] -> TypeEnv -- The competed type environment is gotten from -- Dropping any wired-in things, and then @@ -341,17 +361,14 @@ tidyTypeEnv :: Bool -> NameSet -> TypeEnv -> [CoreBind] -> TypeEnv -- This truncates the type environment to include only the -- exported Ids and things needed from them, which saves space -tidyTypeEnv omit_prags exports type_env tidy_binds - = let type_env1 = filterNameEnv keep_it type_env +tidyTypeEnv omit_prags th exports type_env final_ids + = let type_env1 = filterNameEnv keep_it type_env type_env2 = extendTypeEnvWithIds type_env1 final_ids - type_env3 | omit_prags = mapNameEnv trim_thing type_env2 + type_env3 | omit_prags = mapNameEnv (trimThing th exports) type_env2 | otherwise = type_env2 in type_env3 where - final_ids = [ id | id <- bindersOfBinds tidy_binds, - isExternalName (idName id)] - -- We keep GlobalIds, because they won't appear -- in the bindings from which final_ids are derived! -- (The bindings bind LocalIds.) @@ -359,15 +376,36 @@ tidyTypeEnv omit_prags exports type_env tidy_binds keep_it (AnId id) = isGlobalId id -- Keep GlobalIds (e.g. class ops) keep_it _other = True -- Keep all TyCons, DataCons, and Classes - trim_thing thing - = case thing of - ATyCon tc | mustExposeTyCon exports tc -> thing - | otherwise -> ATyCon (makeTyConAbstract tc) +-------------------------- +isWiredInThing :: TyThing -> Bool +isWiredInThing thing = isWiredInName (getName thing) + +-------------------------- +trimThing :: Bool -> NameSet -> TyThing -> TyThing +-- Trim off inessentials, for boot files and no -O +trimThing th exports (ATyCon tc) + | not th && not (mustExposeTyCon exports tc) + = ATyCon (makeTyConAbstract tc) -- Note [Trimming and Template Haskell] + +trimThing _th _exports (AnId id) + | not (isImplicitId id) + = AnId (id `setIdInfo` vanillaIdInfo) + +trimThing _th _exports other_thing + = other_thing - AnId id | isImplicitId id -> thing - | otherwise -> AnId (id `setIdInfo` vanillaIdInfo) - _other -> thing +{- Note [Trimming and Template Haskell] + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Consider (Trac #2386) this + module M(T, makeOne) where + data T = Yay String + makeOne = [| Yay "Yep" |] +Notice that T is exported abstractly, but makeOne effectively exports it too! +A module that splices in $(makeOne) will then look for a declartion of Yay, +so it'd better be there. Hence, brutally but simply, we switch off type +constructor trimming if TH is enabled in this module. -} + mustExposeTyCon :: NameSet -- Exports -> TyCon -- The tycon @@ -381,13 +419,14 @@ mustExposeTyCon exports tc | isEnumerationTyCon tc -- For an enumeration, exposing the constructors = True -- won't lead to the need for further exposure -- (This includes data types with no constructors.) - | isOpenTyCon tc -- open type family + | isOpenTyCon tc -- Open type family = True + | otherwise -- Newtype, datatype = any exported_con (tyConDataCons tc) -- Expose rep if any datacon or field is exported - || (isNewTyCon tc && isFFITy (snd (newTyConRep tc))) + || (isNewTyCon tc && isFFITy (snd (newTyConRhs tc))) -- Expose the rep for newtypes if the rep is an FFI type. -- For a very annoying reason. 'Foreign import' is meant to -- be able to look through newtypes transparently, but it @@ -402,7 +441,39 @@ tidyInstances tidy_dfun ispecs where tidy ispec = setInstanceDFunId ispec $ tidy_dfun (instanceDFunId ispec) +\end{code} + + +%************************************************************************ +%* * + Implicit bindings +%* * +%************************************************************************ + +Note [Injecting implicit bindings] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +We inject the implict bindings right at the end, in CoreTidy. +Some of these bindings, notably record selectors, are not +constructed in an optimised form. E.g. record selector for + data T = MkT { x :: {-# UNPACK #-} !Int } +Then the unfolding looks like + x = \t. case t of MkT x1 -> let x = I# x1 in x +This generates bad code unless it's first simplified a bit. That is +why CoreUnfold.mkImplicitUnfolding uses simleExprOpt to do a bit of +optimisation first. (Only matters when the selector is used curried; +eg map x ys.) See Trac #2070. + +At one time I tried injecting the implicit bindings *early*, at the +beginning of SimplCore. But that gave rise to real difficulty, +becuase GlobalIds are supposed to have *fixed* IdInfo, but the +simplifier and other core-to-core passes mess with IdInfo all the +time. The straw that broke the camels back was when a class selector +got the wrong arity -- ie the simplifier gave it arity 2, whereas +importing modules were expecting it to have arity 1 (Trac #2844). +It's much safer just to inject them right at the end, after tidying. + +\begin{code} getImplicitBinds :: TypeEnv -> [CoreBind] getImplicitBinds type_env = map get_defn (concatMap implicit_con_ids (typeEnvTyCons type_env) @@ -422,11 +493,7 @@ getImplicitBinds type_env other_implicit_ids _other = [] get_defn :: Id -> CoreBind - get_defn id = NonRec id (tidyExpr emptyTidyEnv rhs) - where - rhs = unfoldingTemplate (idUnfolding id) - -- Don't forget to tidy the body ! Otherwise you get silly things like - -- \ tpl -> case tpl of tpl -> (tpl,tpl) -> tpl + get_defn id = NonRec id (unfoldingTemplate (idUnfolding id)) \end{code} @@ -721,12 +788,13 @@ tidyTopPair :: VarEnv Bool -- in the IdInfo of one early in the group tidyTopPair ext_ids rhs_tidy_env caf_info name' (bndr, rhs) - | isGlobalId bndr -- Injected binding for record selector, etc - = (bndr, tidyExpr rhs_tidy_env rhs) - | otherwise = (bndr', rhs') where - bndr' = mkVanillaGlobal name' ty' idinfo' + bndr' = mkGlobalId details name' ty' idinfo' + -- Preserve the GlobalIdDetails of existing global-ids + details = case globalIdDetails bndr of + NotGlobalId -> VanillaGlobal + old_details -> old_details ty' = tidyTopType (idType bndr) rhs' = tidyExpr rhs_tidy_env rhs idinfo = idInfo bndr @@ -795,7 +863,7 @@ tidyWorker _tidy_env _show_unfold NoWorker = NoWorker tidyWorker tidy_env show_unfold (HasWorker work_id wrap_arity) | show_unfold = HasWorker (tidyVarOcc tidy_env work_id) wrap_arity - | otherwise = WARN( True, ppr work_id ) NoWorker + | otherwise = NoWorker -- NB: do *not* expose the worker if show_unfold is off, -- because that means this thing is a loop breaker or -- marked NOINLINE or something like that @@ -803,8 +871,12 @@ tidyWorker tidy_env show_unfold (HasWorker work_id wrap_arity) -- then you can make the simplifier go into an infinite loop, because -- in effect the unfolding is exposed. See Trac #1709 -- - -- Mind you, it probably should not be w/w'd in the first place; - -- hence the WARN + -- You might think that if show_unfold is False, then the thing should + -- not be w/w'd in the first place. But a legitimate reason is this: + -- the function returns bottom + -- In this case, show_unfold will be false (we don't expose unfoldings + -- for bottoming functions), but we might still have a worker/wrapper + -- split (see Note [Worker-wrapper for bottoming functions] in WorkWrap.lhs \end{code} %************************************************************************