X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FcoreSyn%2FCoreFVs.lhs;h=9d2cc8fcec9b017494ee7924755d2365b417634b;hb=db5031360e21a654c6457f71df60af26ac205f44;hp=ad25384b6c355ca012872f249861e23966775583;hpb=f16228e47dbaf4c5eb710bf507b3b61bc5ad7122;p=ghc-hetmet.git

diff --git a/ghc/compiler/coreSyn/CoreFVs.lhs b/ghc/compiler/coreSyn/CoreFVs.lhs
index ad25384..9d2cc8f 100644
--- a/ghc/compiler/coreSyn/CoreFVs.lhs
+++ b/ghc/compiler/coreSyn/CoreFVs.lhs
@@ -9,9 +9,10 @@ module CoreFVs (
 	exprsFreeVars,	-- [CoreExpr] -> VarSet
 
 	exprSomeFreeVars, exprsSomeFreeVars,
+	exprFreeNames, exprsFreeNames,
 
-	idRuleVars, idFreeVars, idFreeTyVars,
-	ruleSomeFreeVars, ruleRhsFreeVars,
+	idRuleVars, idFreeVars, idFreeTyVars, 
+	ruleRhsFreeVars, rulesRhsFreeVars,
 	ruleLhsFreeNames, ruleLhsFreeIds, 
 
 	CoreExprWithFVs,	-- = AnnExpr Id VarSet
@@ -23,11 +24,15 @@ module CoreFVs (
 #include "HsVersions.h"
 
 import CoreSyn
-import Id		( Id, idType, idSpecialisation )
+import Id		( Id, idType, idSpecialisation, isLocalId )
+import IdInfo		( specInfoFreeVars )
 import NameSet
+import UniqFM		( delFromUFM )
+import Name		( isExternalName )
 import VarSet
 import Var		( Var, isId, isLocalVar, varName )
-import Type		( tyVarsOfType, namesOfType )
+import Type		( tyVarsOfType )
+import TcType		( tyClsNamesOfType )
 import Util		( mapAndUnzip )
 import Outputable
 \end{code}
@@ -70,8 +75,8 @@ type InterestingVarFun = Var -> Bool	-- True <=> interesting
 
 \begin{code}
 type FV = InterestingVarFun 
-	  -> VarSet		-- In scope
-	  -> VarSet		-- Free vars
+	-> VarSet		-- In scope
+	-> VarSet		-- Free vars
 
 union :: FV -> FV -> FV
 union fv1 fv2 fv_cand in_scope = fv1 fv_cand in_scope `unionVarSet` fv2 fv_cand in_scope
@@ -127,8 +132,9 @@ expr_fvs (Note _ expr)   = expr_fvs expr
 expr_fvs (App fun arg)   = expr_fvs fun `union` expr_fvs arg
 expr_fvs (Lam bndr body) = addBndr bndr (expr_fvs body)
 
-expr_fvs (Case scrut bndr alts)
-  = expr_fvs scrut `union` addBndr bndr (foldr (union . alt_fvs) noVars alts)
+expr_fvs (Case scrut bndr ty alts)
+  = expr_fvs scrut `union` someVars (tyVarsOfType ty) `union` addBndr bndr  
+      (foldr (union . alt_fvs) noVars alts)
   where
     alt_fvs (con, bndrs, rhs) = addBndrs bndrs (expr_fvs rhs)
 
@@ -139,6 +145,9 @@ expr_fvs (Let (Rec pairs) body)
   = addBndrs bndrs (foldr (union . expr_fvs) (expr_fvs body) rhss)
   where
     (bndrs,rhss) = unzip pairs
+
+---------
+exprs_fvs exprs = foldr (union . expr_fvs) noVars exprs
 \end{code}
 
 
@@ -148,47 +157,46 @@ expr_fvs (Let (Rec pairs) body)
 %*									*
 %************************************************************************
 
-exprFreeNames finds the free *names* of an expression, notably
+exprFreeNames finds the free *external* *names* of an expression, notably
 including the names of type constructors (which of course do not show
 up in exprFreeVars).  Similarly ruleLhsFreeNames.  The latter is used
-when deciding whethera rule is an orphan.  In particular, suppose that
+when deciding whether a rule is an orphan.  In particular, suppose that
 T is defined in this module; we want to avoid declaring that a rule like
 	fromIntegral T = fromIntegral_T
 is an orphan.  Of course it isn't, an declaring it an orphan would
 make the whole module an orphan module, which is bad.
 
+There's no need to delete local binders, because they will all
+be *internal* names.
+
 \begin{code}
-ruleLhsFreeNames :: IdCoreRule -> NameSet
-ruleLhsFreeNames (fn, BuiltinRule _) = unitNameSet (varName fn)
-ruleLhsFreeNames (fn, Rule _ tpl_vars tpl_args rhs)
-  = addOneToNameSet (exprsFreeNames tpl_args `del_binders` tpl_vars) (varName fn)
+ruleLhsFreeNames :: CoreRule -> NameSet
+ruleLhsFreeNames (BuiltinRule { ru_fn = fn }) = unitNameSet fn
+ruleLhsFreeNames (Rule { ru_fn = fn, ru_bndrs = tpl_vars, ru_args = tpl_args })
+  = addOneToNameSet (exprsFreeNames tpl_args) fn
 
 exprFreeNames :: CoreExpr -> NameSet
-exprFreeNames (Var v) 	= unitNameSet (varName v)
-exprFreeNames (Lit _) 	= emptyNameSet
-exprFreeNames (Type ty) = namesOfType ty
-exprFreeNames (App e1 e2) = exprFreeNames e1 `unionNameSets` exprFreeNames e2
-exprFreeNames (Lam v e)   = exprFreeNames e `delFromNameSet` varName v
-exprFreeNames (Note n e)  = exprFreeNames e
-
-exprFreeNames (Let (NonRec b r) e) = (exprFreeNames e `delFromNameSet` varName b)
-				     `unionNameSets` exprFreeNames r
-
-exprFreeNames (Let (Rec prs) e) = (exprsFreeNames rs `unionNameSets` exprFreeNames e)
-				  `del_binders` bs
-				where
-				  (bs, rs) = unzip prs
-
-exprFreeNames (Case e b as) = exprFreeNames e `unionNameSets` 
-			      (unionManyNameSets (map altFreeNames as) `delFromNameSet` varName b)
-
--- Helpers
-altFreeNames (_,bs,r) = exprFreeNames r `del_binders` bs
+-- Find the free *external* names of an expression
+exprFreeNames e
+  = go e
+  where
+    go (Var v) 
+      | isExternalName n    = unitNameSet n
+      | otherwise	    = emptyNameSet
+      where n = varName v
+    go (Lit _) 	   	    = emptyNameSet
+    go (Type ty)   	    = tyClsNamesOfType ty	-- Don't need free tyvars
+    go (App e1 e2) 	    = go e1 `unionNameSets` go e2
+    go (Lam v e)   	    = go e `delFromNameSet` varName v
+    go (Note n e)  	    = go e   
+    go (Let (NonRec b r) e) = go e `unionNameSets` go r
+    go (Let (Rec prs) e)    = exprsFreeNames (map snd prs) `unionNameSets` go e
+    go (Case e b ty as)     = go e `unionNameSets` tyClsNamesOfType ty 
+                              `unionNameSets` unionManyNameSets (map go_alt as)
+
+    go_alt (_,_,r) = go r
 
 exprsFreeNames es = foldr (unionNameSets . exprFreeNames) emptyNameSet es
-
-del_binders :: NameSet -> [Var] -> NameSet
-del_binders names bndrs = foldl (\s b -> delFromNameSet s (varName b)) names bndrs
 \end{code}
 
 %************************************************************************
@@ -200,26 +208,26 @@ del_binders names bndrs = foldl (\s b -> delFromNameSet s (varName b)) names bnd
 
 \begin{code}
 ruleRhsFreeVars :: CoreRule -> VarSet
-ruleRhsFreeVars (BuiltinRule _) = noFVs
-ruleRhsFreeVars (Rule str tpl_vars tpl_args rhs)
-  = rule_fvs isLocalVar emptyVarSet
+ruleRhsFreeVars (BuiltinRule {}) = noFVs
+ruleRhsFreeVars (Rule { ru_fn = fn, ru_bndrs = bndrs, ru_rhs = rhs })
+  = delFromUFM fvs fn
+	-- Hack alert!
+	-- Don't include the Id in its own rhs free-var set.
+	-- Otherwise the occurrence analyser makes bindings recursive
+	-- that shoudn't be.  E.g.
+	--	RULE:  f (f x y) z  ==>  f x (f y z)
   where
-    rule_fvs = addBndrs tpl_vars (expr_fvs rhs)
+    fvs = addBndrs bndrs (expr_fvs rhs) isLocalVar emptyVarSet
 
-ruleSomeFreeVars :: InterestingVarFun -> CoreRule -> VarSet
-ruleSomeFreeVars interesting (BuiltinRule _) = noFVs
-ruleSomeFreeVars interesting (Rule _ tpl_vars tpl_args rhs)
-  = rule_fvs interesting emptyVarSet
-  where
-    rule_fvs = addBndrs tpl_vars $
-	       foldr (union . expr_fvs) (expr_fvs rhs) tpl_args
+rulesRhsFreeVars :: [CoreRule] -> VarSet
+rulesRhsFreeVars rules
+  = foldr (unionVarSet . ruleRhsFreeVars) emptyVarSet rules
 
 ruleLhsFreeIds :: CoreRule -> VarSet
--- This finds all the free Ids on the LHS of the rule
--- *including* imported ids
-ruleLhsFreeIds (BuiltinRule _) = noFVs
-ruleLhsFreeIds (Rule _ tpl_vars tpl_args rhs)
-  = foldl delVarSet (exprsSomeFreeVars isId tpl_args) tpl_vars
+-- This finds all locally-defined free Ids on the LHS of the rule
+ruleLhsFreeIds (BuiltinRule {}) = noFVs
+ruleLhsFreeIds (Rule { ru_bndrs = bndrs, ru_args = args })
+  = addBndrs bndrs (exprs_fvs args) isLocalId emptyVarSet
 \end{code}
 
 
@@ -289,11 +297,11 @@ idFreeTyVars :: Id -> TyVarSet
 -- Only local Ids conjured up locally, can have free type variables.
 -- (During type checking top-level Ids can have free tyvars)
 idFreeTyVars id = tyVarsOfType (idType id)
--- | isLocalId id = tyVarsOfType (idType id)
--- | otherwise    = emptyVarSet
+--  | isLocalId id = tyVarsOfType (idType id)
+--  | otherwise    = emptyVarSet
 
 idRuleVars ::Id -> VarSet
-idRuleVars id = ASSERT( isId id) rulesRhsFreeVars (idSpecialisation id)
+idRuleVars id = ASSERT( isId id) specInfoFreeVars (idSpecialisation id)
 \end{code}
 
 
@@ -329,9 +337,10 @@ freeVars (App fun arg)
     fun2 = freeVars fun
     arg2 = freeVars arg
 
-freeVars (Case scrut bndr alts)
-  = ((bndr `delBinderFV` alts_fvs) `unionFVs` freeVarsOf scrut2,
-     AnnCase scrut2 bndr alts2)
+freeVars (Case scrut bndr ty alts)
+-- gaw 2004
+  = ((bndr `delBinderFV` alts_fvs) `unionFVs` freeVarsOf scrut2 `unionFVs` tyVarsOfType ty,
+     AnnCase scrut2 bndr ty alts2)
   where
     scrut2 = freeVars scrut