From 61b0ea8101e1128e6b0e59476a220c99e3d4f211 Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Thu, 26 Apr 2007 10:11:27 +0000 Subject: [PATCH] Attach free variables rather than in-scope variables to breakpoints This speeds up the debugger quite a bit, we're now only about 30% slower than ordinary GHCi, and still adding breakpoints to every sub-expression. Also we now get to see the free variables in recursive bindings, which wasn't working properly before. --- compiler/deSugar/Coverage.lhs | 148 +++++++++++++++++++++++++++-------------- 1 file changed, 98 insertions(+), 50 deletions(-) diff --git a/compiler/deSugar/Coverage.lhs b/compiler/deSugar/Coverage.lhs index 74e0c7d..4feb4f4 100644 --- a/compiler/deSugar/Coverage.lhs +++ b/compiler/deSugar/Coverage.lhs @@ -19,9 +19,11 @@ import ErrUtils import Name import Bag import Var +import VarSet import Data.List import FastString import StaticFlags +import UniqFM import Data.Array import System.Time (ClockTime(..)) @@ -61,13 +63,13 @@ addCoverageTicksToBinds dflags mod mod_loc binds = do let mod_name = moduleNameString (moduleName mod) - let (binds1,st) + let (binds1,_,st) = unTM (addTickLHsBinds binds) - TickEnv { locals = emptyOccEnv } TT { modName = mod_name , declPath = [] , tickBoxCount = 0 , mixEntries = [] + , inScope = emptyVarSet } let entries = reverse $ mixEntries st @@ -84,6 +86,7 @@ addCoverageTicksToBinds dflags mod mod_loc binds = do -- Todo: use proper src span type breakArray <- newBreakArray $ length entries + let locsTicks = listArray (0,tickBoxCount st-1) [ span | (span,_,_) <- entries ] varsTicks = listArray (0,tickBoxCount st-1) @@ -119,8 +122,10 @@ addTickLHsBind (L pos (funBind@(FunBind { fun_id = (L _ id) }))) = do let name = getOccString id decl_path <- getPathEntry - mg@(MatchGroup matches' ty) <- addPathEntry name - $ addTickMatchGroup (fun_matches funBind) + (fvs, mg@(MatchGroup matches' ty)) <- + getFreeVars $ + addPathEntry name $ + addTickMatchGroup (fun_matches funBind) -- Todo: we don't want redundant ticks on simple pattern bindings if not opt_Hpc && isSimplePatBind funBind @@ -131,7 +136,8 @@ addTickLHsBind (L pos (funBind@(FunBind { fun_id = (L _ id) }))) = do else do tick_no <- allocATickBox (if null decl_path then TopLevelBox [name] - else LocalBox (name : decl_path)) pos + else LocalBox (name : decl_path)) + pos fvs return $ L pos $ funBind { fun_matches = MatchGroup matches' ty , fun_tick = tick_no @@ -163,8 +169,7 @@ addTickLHsBind other = return other -- add a tick to the expression no matter what it is addTickLHsExprAlways :: LHsExpr Id -> TM (LHsExpr Id) addTickLHsExprAlways (L pos e0) = do - e1 <- addTickHsExpr e0 - allocTickBox ExpBox pos e1 + allocTickBox ExpBox pos $ addTickHsExpr e0 addTickLHsExprNeverOrAlways :: LHsExpr Id -> TM (LHsExpr Id) addTickLHsExprNeverOrAlways e @@ -187,11 +192,11 @@ addTickLHsExprNever (L pos e0) = do -- selectively add ticks to interesting expressions addTickLHsExpr :: LHsExpr Id -> TM (LHsExpr Id) addTickLHsExpr (L pos e0) = do - e1 <- addTickHsExpr e0 if opt_Hpc || isGoodBreakExpr e0 then do - allocTickBox ExpBox pos e1 - else + allocTickBox ExpBox pos $ addTickHsExpr e0 + else do + e1 <- addTickHsExpr e0 return $ L pos e1 -- general heuristic: expressions which do not denote values are good break points @@ -210,9 +215,9 @@ isGoodBreakExpr other = False addTickLHsExprOptAlt :: Bool -> LHsExpr Id -> TM (LHsExpr Id) addTickLHsExprOptAlt oneOfMany (L pos e0) | not opt_Hpc = addTickLHsExpr (L pos e0) - | otherwise = do - e1 <- addTickHsExpr e0 - allocTickBox (if oneOfMany then AltBox else ExpBox) pos e1 + | otherwise = + allocTickBox (if oneOfMany then AltBox else ExpBox) pos $ + addTickHsExpr e0 addBinTickLHsExpr :: (Bool -> BoxLabel) -> LHsExpr Id -> TM (LHsExpr Id) addBinTickLHsExpr boxLabel (L pos e0) = do @@ -220,7 +225,7 @@ addBinTickLHsExpr boxLabel (L pos e0) = do allocBinTickBox boxLabel $ L pos e1 addTickHsExpr :: HsExpr Id -> TM (HsExpr Id) -addTickHsExpr e@(HsVar _) = return e +addTickHsExpr e@(HsVar id) = do freeVar id; return e addTickHsExpr e@(HsIPVar _) = return e addTickHsExpr e@(HsOverLit _) = return e addTickHsExpr e@(HsLit _) = return e @@ -302,8 +307,8 @@ addTickHsExpr (ArithSeq ty arith_seq) = (return ty) (addTickArithSeqInfo arith_seq) addTickHsExpr (HsTickPragma (file,(l1,c1),(l2,c2)) (L pos e0)) = do - e1 <- addTickHsExpr e0 - e2 <- allocTickBox (ExternalBox (unpackFS file) (P l1 c1 l2 c2)) pos e1 + e2 <- allocTickBox (ExternalBox (unpackFS file) (P l1 c1 l2 c2)) pos $ + addTickHsExpr e0 return $ unLoc e2 addTickHsExpr (PArrSeq {}) = error "addTickHsExpr: PArrSeq" addTickHsExpr (HsSCC {}) = error "addTickHsExpr: HsSCC" @@ -354,8 +359,8 @@ addTickMatch isOneOfMany (Match pats opSig gRHSs) = addTickGRHSs :: Bool -> GRHSs Id -> TM (GRHSs Id) addTickGRHSs isOneOfMany (GRHSs guarded local_binds) = do - local_binds' <- addTickHsLocalBinds local_binds bindLocals binders $ do + local_binds' <- addTickHsLocalBinds local_binds guarded' <- mapM (liftL (addTickGRHS isOneOfMany)) guarded return $ GRHSs guarded' local_binds' where @@ -405,9 +410,10 @@ addTickStmt isGuard (ExprStmt e bind' ty) = do | otherwise = addTickLHsExprAlways e addTickStmt isGuard (LetStmt binds) = do + let binders = map unLoc (collectLocalBinders binds) e <- liftM LetStmt - (addTickHsLocalBinds binds) - return (e, map unLoc $ collectLocalBinders binds) + (bindLocals binders $ addTickHsLocalBinds binds) + return (e, binders) addTickStmt isGuard (ParStmt pairs) = do e <- liftM ParStmt (mapM process pairs) return (e, []) @@ -509,62 +515,102 @@ data TickTransState = TT { modName :: String , declPath :: [String] , tickBoxCount:: Int , mixEntries :: [MixEntry] - + , inScope :: VarSet } -- deriving Show -newtype TickEnv = TickEnv { locals :: OccEnv Id } - -data TM a = TM { unTM :: TickEnv -> TickTransState -> (a,TickTransState) } +type FreeVars = OccEnv Id +noFVs = emptyOccEnv + +-- Note [freevars] +-- For breakpoints we want to collect the free variables of an +-- expression for pinning on the HsTick. We don't want to collect +-- *all* free variables though: in particular there's no point pinning +-- on free variables that are will otherwise be in scope at the GHCi +-- prompt, which means all top-level bindings. Unfortunately detecting +-- top-level bindings isn't easy (collectHsBindsBinders on the top-level +-- bindings doesn't do it), so we keep track of a set of "in-scope" +-- variables in addition to the free variables, and the former is used +-- to filter additions to the latter. This gives us complete control +-- over what free variables we track. + +data TM a = TM { unTM :: TickTransState -> (a,FreeVars,TickTransState) } + -- a combination of a state monad (TickTransState) and a writer + -- monad (FreeVars). instance Monad TM where - return a = TM $ \ e st -> (a,st) - (TM m) >>= k = TM $ \ e st -> case m e st of - (r1,st1) -> unTM (k r1) e st1 + return a = TM $ \ st -> (a,noFVs,st) + (TM m) >>= k = TM $ \ st -> case m st of + (r1,fv1,st1) -> + case unTM (k r1) st1 of + (r2,fv2,st2) -> + (r2, fv1 `plusOccEnv` fv2, st2) + +getState :: TM TickTransState +getState = TM $ \st -> (st, noFVs, st) ---addTick :: LHsExpr Id -> TM (LHsExpr Id) ---addTick e = TM $ \ uq -> (e,succ uq,[(uq,getLoc e)]) +setState :: (TickTransState -> TickTransState) -> TM () +setState f = TM $ \st -> ((), noFVs, f st) + +withState :: (TickTransState -> TickTransState) -> TM a -> TM a +withState f (TM m) = TM $ \st -> case m (f st) of + (a, fvs, st') -> (a, fvs, st') + +getFreeVars :: TM a -> TM (FreeVars, a) +getFreeVars (TM m) + = TM $ \st -> case m st of (a, fv, st') -> ((fv,a), fv, st') + +freeVar :: Id -> TM () +freeVar id = TM $ \st -> + if id `elemVarSet` inScope st + then ((), unitOccEnv (nameOccName (idName id)) id, st) + else ((), noFVs, st) addPathEntry :: String -> TM a -> TM a -addPathEntry nm (TM m) = TM $ \ e st -> case m e (st { declPath = declPath st ++ [nm] }) of - (r,st') -> (r,st' { declPath = declPath st }) +addPathEntry nm = withState (\st -> st { declPath = declPath st ++ [nm] }) getPathEntry :: TM [String] -getPathEntry = TM $ \ e st -> (declPath st,st) +getPathEntry = declPath `liftM` getState bindLocals :: [Id] -> TM a -> TM a bindLocals new_ids (TM m) - = TM $ \ e st -> m e{locals = locals e `extendOccEnvList` occnamed_ids} st - where occnamed_ids = [ (nameOccName (idName id),id) | id <- new_ids ] + = TM $ \ st -> case m st{ inScope = inScope st `extendVarSetList` new_ids } of + (r, fv, st') -> (r, fv `delListFromUFM` occs, st') + where occs = [ nameOccName (idName id) | id <- new_ids ] -- the tick application inherits the source position of its -- expression argument to support nested box allocations -allocTickBox :: BoxLabel -> SrcSpan -> HsExpr Id -> TM (LHsExpr Id) -allocTickBox boxLabel pos e | isGoodSrcSpan pos = TM $ \ env st -> - let me = (pos, map (nameOccName.idName) ids, boxLabel) - c = tickBoxCount st - mes = mixEntries st - ids = occEnvElts (locals env) - in ( L pos (HsTick c ids (L pos e)) - , st {tickBoxCount=c+1,mixEntries=me:mes} - ) -allocTickBox boxLabel pos e = return (L pos e) +allocTickBox :: BoxLabel -> SrcSpan -> TM (HsExpr Id) -> TM (LHsExpr Id) +allocTickBox boxLabel pos m | isGoodSrcSpan pos = do + (fvs, e) <- getFreeVars m + TM $ \st -> + let c = tickBoxCount st + ids = occEnvElts fvs + mes = mixEntries st + me = (pos, map (nameOccName.idName) ids, boxLabel) + in + ( L pos (HsTick c ids (L pos e)) + , fvs + , st {tickBoxCount=c+1,mixEntries=me:mes} + ) +allocTickBox boxLabel pos m = do e <- m; return (L pos e) -- the tick application inherits the source position of its -- expression argument to support nested box allocations -allocATickBox :: BoxLabel -> SrcSpan -> TM (Maybe (Int,[Id])) -allocATickBox boxLabel pos | isGoodSrcSpan pos = TM $ \ env st -> +allocATickBox :: BoxLabel -> SrcSpan -> FreeVars -> TM (Maybe (Int,[Id])) +allocATickBox boxLabel pos fvs | isGoodSrcSpan pos = TM $ \ st -> let me = (pos, map (nameOccName.idName) ids, boxLabel) c = tickBoxCount st mes = mixEntries st - ids = occEnvElts (locals env) + ids = occEnvElts fvs in ( Just (c, ids) - , st {tickBoxCount=c+1,mixEntries=me:mes} + , noFVs + , st {tickBoxCount=c+1, mixEntries=me:mes} ) -allocATickBox boxLabel e = return Nothing +allocATickBox boxLabel pos fvs = return Nothing allocBinTickBox :: (Bool -> BoxLabel) -> LHsExpr Id -> TM (LHsExpr Id) -allocBinTickBox boxLabel (L pos e) | isGoodSrcSpan pos = TM $ \ _ st -> +allocBinTickBox boxLabel (L pos e) | isGoodSrcSpan pos = TM $ \ st -> let meT = (pos,[],boxLabel True) meF = (pos,[],boxLabel False) meE = (pos,[],ExpBox) @@ -576,10 +622,12 @@ allocBinTickBox boxLabel (L pos e) | isGoodSrcSpan pos = TM $ \ _ st -> -- notice that F and T are reversed, -- because we are building the list in -- reverse... - , st {tickBoxCount=c+3,mixEntries=meF:meT:meE:mes} + , noFVs + , st {tickBoxCount=c+3 , mixEntries=meF:meT:meE:mes} ) else ( L pos $ HsTick c [] $ L pos e + , noFVs , st {tickBoxCount=c+1,mixEntries=meE:mes} ) -- 1.7.10.4