Remove ext-core

[ghc-hetmet.git] / utils / ext-core / Language / Core / ElimDeadCode.hs

diff --git a/utils/ext-core/Language/Core/ElimDeadCode.hs b/utils/ext-core/Language/Core/ElimDeadCode.hs
deleted file mode 100644 (file)
index 8817edb..0000000
--- a/utils/ext-core/Language/Core/ElimDeadCode.hs
+++ /dev/null
@@ -1,129 +0,0 @@
-{- 
-   This module eliminates unused top-level bindings, under the
-   assumption that all top-level bindings with qualified names
-   should be retained.
--}
-module Language.Core.ElimDeadCode(elimDeadCode) where
-
-import Language.Core.Core
-import Language.Core.Printer()
-import Language.Core.CoreUtils
-import Language.Core.Utils
-
-import Control.Monad.Reader
-import Data.Generics
-import Data.List
-import Data.Maybe
-import qualified Data.Map as M
-import qualified Data.Set as S
-
-elimDeadCode :: Bool -> Module -> Module
--- exports = true <=> it's assumed we want to keep exported functions;
--- otherwise, we assume the module is "closed" and eliminate everything
--- not reachable from Main
-elimDeadCode exports (Module mn tdefs vdefgs) = runReader (do
-  (usedVars, usedDcons, usedTcons) <- findUsed emptySet 
-     (mkStartSet exports mn vdefgs) 
-  let isUsed (Vdef (v,_,_)) = v `S.member` usedVars
-  let newVdefgs = filterVdefgs isUsed vdefgs
-  let newTdefs  = filter (tdefIsUsed usedTcons usedDcons) tdefs in
-    return $ Module mn newTdefs newVdefgs) ((mkVarEnv vdefgs), mkTyEnv tdefs)
-
-tdefIsUsed :: S.Set (Qual Tcon) -> S.Set (Qual Dcon) -> Tdef -> Bool
-tdefIsUsed tcs dcs (Data qtc _ cdefs) = 
-  (qtc `S.member` tcs || any (\ (Constr qdc _ _) -> qdc `S.member` dcs) cdefs)
-tdefIsUsed tcs _ (Newtype qtc qtc_co _ _) = 
-  qtc `S.member` tcs || qtc_co `S.member` tcs
-
-mkVarEnv :: [Vdefg] -> M.Map (Qual Var) Exp
-mkVarEnv vgs =
-  let vdefs = flattenBinds vgs in
-    M.fromList [(v, e) | (Vdef (v, _, e)) <- vdefs]
-
--- if there is a Newtype qtc qtc_co ty,
--- generate: qtc |-> ty and qtc_co |-> ty
--- roughly the same for rhs's of Data decls
-mkTyEnv :: [Tdef] -> M.Map (Qual Tcon) [Ty]
-mkTyEnv tdefs = 
-  M.fromList ([(qtc, [ty]) | (Newtype qtc _ _ ty) <- tdefs]
-         ++   [(qtc, [ty]) | (Newtype _ qtc _ ty) <- tdefs]
-         ++   concatMap (\ td -> case td of
-                                   Data qtc _ cdefs -> [(qtc, concatMap 
-                                     (\ (Constr _ _ ts) -> ts) cdefs)]
-                                   _ -> []) tdefs)
-
-findUsed :: DeadSet -> DeadSet -> DeadM DeadSet
-findUsed _old@(oldVars,oldDcs,oldTcs) _new@(newVars,newDcs,newTcs) = do
-  let (todoVars, todoTcs) = ((S.\\) newVars oldVars, (S.\\) newTcs oldTcs)
-  let nextOld = (oldVars `S.union` todoVars, oldDcs `S.union` newDcs,
-                 oldTcs `S.union` todoTcs)
-  nextStuff <- getVarsAndConsIn (todoVars, todoTcs)
-  if (S.null todoVars && S.null todoTcs)
-      then return nextOld
-      else findUsed nextOld nextStuff
-
-getVarsAndConsIn :: (S.Set (Qual Var), S.Set (Qual Tcon)) -> DeadM DeadSet
-getVarsAndConsIn (vs, tcs) = do
-  vs1 <- mapM varsAndConsInOne (S.toList vs)
-  ts1 <- mapM varsAndConsInOne' (S.toList tcs)
-  let (vs'::[S.Set (Qual Var)], dcs'::[S.Set (Qual Dcon)],
-        ts'::[S.Set (Qual Tcon)]) = unzip3 (vs1 ++ ts1)
-  return (foldl' S.union S.empty vs', foldl' S.union S.empty dcs',
-          foldl' S.union S.empty ts')
-
-varsAndConsInOne :: Qual Var -> DeadM DeadSet
-varsAndConsInOne vr = do
-  def <- findDefn vr
-  return $ maybe emptySet 
-    (noNames emptySet unionThree (mkQ emptySet usedNamesAll)) def
-
-varsAndConsInOne' :: Qual Tcon -> DeadM DeadSet
-varsAndConsInOne' tc = do
-  ty <- findRepTy tc
-  return $ maybe emptySet
-    (noNames emptySet unionThree 
-              (mkQ emptySet usedStuffTys)) ty
-
-emptySet :: DeadSet
-emptySet = (S.empty, S.empty, S.empty)
-mkStartSet :: Bool -> AnMname -> [Vdefg] -> DeadSet
--- Initially, we assume the definitions of any exported functions are not
--- dead, and work backwards from there.
-mkStartSet exports mn vds = 
-  (S.fromList (filter ((== Just mn) . getModule) (if exports then exportedNames vds else [mainVar])), 
-   S.empty, S.empty)
-
-exportedNames :: [Vdefg] -> [Qual Var]
-exportedNames vdefgs = 
-  let vds = flattenBinds vdefgs in
-    filter isQual (ns vds)
-      where isQual    = isJust . fst
-            ns = map (\ (Vdef (n,_,_)) -> n)
-
-type DeadSet = (S.Set (Qual Var), S.Set (Qual Dcon), S.Set (Qual Tcon))
-type DeadM = Reader (M.Map (Qual Var) Exp, M.Map (Qual Tcon) [Ty])
-
-findDefn :: Qual Var -> DeadM (Maybe Exp)
-findDefn vr = asks ((M.lookup vr) . fst)
-findRepTy :: Qual Tcon -> DeadM (Maybe [Ty])
-findRepTy tc = asks ((M.lookup tc) . snd)
-
-unionThree :: DeadSet -> DeadSet -> DeadSet
-unionThree (a,b,c) (d,e,f) = (a `S.union` d, b `S.union` e, c `S.union` f)
-
-usedNamesAll :: Exp -> DeadSet
-usedNamesAll = (noNames emptySet unionThree 
-  ((mkQ emptySet usedStuff) `extQ` usedStuffTys `extQ` usedStuffAlts))
-            
-usedStuff :: Exp -> DeadSet
-usedStuff (Var qv)  = (S.singleton qv, S.empty, S.empty)
-usedStuff (Dcon dc) = (S.empty, S.singleton dc, S.empty)
-usedStuff _         = emptySet
-
-usedStuffAlts :: Alt -> DeadSet
-usedStuffAlts (Acon qdc _ _ _) = (S.empty, S.singleton qdc, S.empty)
-usedStuffAlts _ = emptySet
-
-usedStuffTys :: Ty -> DeadSet
-usedStuffTys (Tcon qtc) = (S.empty, S.empty, S.singleton qtc)
-usedStuffTys _          = emptySet