-- * Selective free variables of expressions
InterestingVarFun,
exprSomeFreeVars, exprsSomeFreeVars,
- exprFreeNames, exprsFreeNames,
-- * Free variables of Rules, Vars and Ids
varTypeTyVars, varTypeTcTyVars,
idUnfoldingVars, idFreeVars, idRuleAndUnfoldingVars,
- idRuleVars, idRuleRhsVars,
+ idRuleVars, idRuleRhsVars, stableUnfoldingVars,
ruleRhsFreeVars, rulesFreeVars,
- ruleLhsFreeNames, ruleLhsFreeIds,
+ ruleLhsOrphNames, ruleLhsFreeIds,
-- * Core syntax tree annotation with free variables
CoreExprWithFVs, -- = AnnExpr Id VarSet
import Var
import TcType
import Util
+import BasicTypes( Activation )
import Outputable
\end{code}
%************************************************************************
\begin{code}
--- | Similar to 'exprFreeNames'. However, this is used when deciding whether
+-- | ruleLhsOrphNames is used 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:
--
--
-- is an orphan. Of course it isn't, and declaring it an orphan would
-- make the whole module an orphan module, which is bad.
-ruleLhsFreeNames :: CoreRule -> NameSet
-ruleLhsFreeNames (BuiltinRule { ru_fn = fn }) = unitNameSet fn
-ruleLhsFreeNames (Rule { ru_fn = fn, ru_args = tpl_args })
- = addOneToNameSet (exprsFreeNames tpl_args) fn
+ruleLhsOrphNames :: CoreRule -> NameSet
+ruleLhsOrphNames (BuiltinRule { ru_fn = fn }) = unitNameSet fn
+ruleLhsOrphNames (Rule { ru_fn = fn, ru_args = tpl_args })
+ = addOneToNameSet (exprsOrphNames tpl_args) fn
+ -- No need to delete bndrs, because
+ -- exprsOrphNames finds only External names
-- | Finds the free /external/ names of an expression, notably
-- including the names of type constructors (which of course do not show
-- up in 'exprFreeVars').
-exprFreeNames :: CoreExpr -> NameSet
+exprOrphNames :: CoreExpr -> NameSet
-- There's no need to delete local binders, because they will all
-- be /internal/ names.
-exprFreeNames e
+exprOrphNames e
= go e
where
go (Var v)
| otherwise = emptyNameSet
where n = idName v
go (Lit _) = emptyNameSet
- go (Type ty) = tyClsNamesOfType ty -- Don't need free tyvars
+ go (Type ty) = orphNamesOfType ty -- Don't need free tyvars
go (App e1 e2) = go e1 `unionNameSets` go e2
go (Lam v e) = go e `delFromNameSet` idName v
go (Note _ e) = go e
- go (Cast e co) = go e `unionNameSets` tyClsNamesOfType co
+ go (Cast e co) = go e `unionNameSets` orphNamesOfType co
go (Let (NonRec _ r) e) = go e `unionNameSets` go r
- go (Let (Rec prs) e) = exprsFreeNames (map snd prs) `unionNameSets` go e
- go (Case e _ ty as) = go e `unionNameSets` tyClsNamesOfType ty
+ go (Let (Rec prs) e) = exprsOrphNames (map snd prs) `unionNameSets` go e
+ go (Case e _ ty as) = go e `unionNameSets` orphNamesOfType ty
`unionNameSets` unionManyNameSets (map go_alt as)
go_alt (_,_,r) = go r
--- | Finds the free /external/ names of several expressions: see 'exprFreeNames' for details
-exprsFreeNames :: [CoreExpr] -> NameSet
-exprsFreeNames es = foldr (unionNameSets . exprFreeNames) emptyNameSet es
+-- | Finds the free /external/ names of several expressions: see 'exprOrphNames' for details
+exprsOrphNames :: [CoreExpr] -> NameSet
+exprsOrphNames es = foldr (unionNameSets . exprOrphNames) emptyNameSet es
\end{code}
%************************************************************************
where
fvs = addBndrs bndrs (exprs_fvs (rhs:args)) isLocalVar emptyVarSet
+idRuleRhsVars :: (Activation -> Bool) -> Id -> VarSet
+-- Just the variables free on the *rhs* of a rule
+idRuleRhsVars is_active id
+ = foldr (unionVarSet . get_fvs) emptyVarSet (idCoreRules id)
+ where
+ get_fvs (Rule { ru_fn = fn, ru_bndrs = bndrs
+ , ru_rhs = rhs, ru_act = act })
+ | is_active act
+ -- See Note [Finding rule RHS free vars] in OccAnal.lhs
+ = delFromUFM fvs fn -- Note [Rule free var hack]
+ where
+ fvs = addBndrs bndrs (expr_fvs rhs) isLocalVar emptyVarSet
+ get_fvs _ = noFVs
+
-- | Those variables free in the right hand side of several rules
rulesFreeVars :: [CoreRule] -> VarSet
rulesFreeVars rules = foldr (unionVarSet . ruleFreeVars) emptyVarSet rules
bndrRuleAndUnfoldingVars ::Var -> VarSet
-- A 'let' can bind a type variable, and idRuleVars assumes
-- it's seeing an Id. This function tests first.
-bndrRuleAndUnfoldingVars v | isTyVar v = emptyVarSet
+bndrRuleAndUnfoldingVars v | isTyCoVar v = emptyVarSet
| otherwise = idRuleAndUnfoldingVars v
idRuleAndUnfoldingVars :: Id -> VarSet
idRuleVars ::Id -> VarSet -- Does *not* include CoreUnfolding vars
idRuleVars id = ASSERT( isId id) specInfoFreeVars (idSpecialisation id)
-idRuleRhsVars :: Id -> VarSet -- Does *not* include the CoreUnfolding vars
--- Just the variables free on the *rhs* of a rule
--- See Note [Choosing loop breakers] in Simplify.lhs
-idRuleRhsVars id = foldr (unionVarSet . ruleRhsFreeVars)
- emptyVarSet
- (idCoreRules id)
-
idUnfoldingVars :: Id -> VarSet
-- Produce free vars for an unfolding, but NOT for an ordinary
-- (non-inline) unfolding, since it is a dup of the rhs
-idUnfoldingVars id
- = case idUnfolding id of
- CoreUnfolding { uf_tmpl = rhs, uf_guidance = InlineRule {} }
- -> exprFreeVars rhs
- DFunUnfolding _ args -> exprsFreeVars args
- _ -> emptyVarSet
+-- and we'll get exponential behaviour if we look at both unf and rhs!
+-- But do look at the *real* unfolding, even for loop breakers, else
+-- we might get out-of-scope variables
+idUnfoldingVars id = stableUnfoldingVars (realIdUnfolding id)
+
+stableUnfoldingVars :: Unfolding -> VarSet
+stableUnfoldingVars (CoreUnfolding { uf_tmpl = rhs, uf_src = src })
+ | isStableSource src = exprFreeVars rhs
+stableUnfoldingVars (DFunUnfolding _ _ args) = exprsFreeVars (dfunArgExprs args)
+stableUnfoldingVars _ = emptyVarSet
\end{code}
projects / ghc-hetmet.git / blobdiff