exprFreeNames, exprsFreeNames,
-- * Free variables of Rules, Vars and Ids
- idRuleVars, idRuleRhsVars, idFreeVars, idInlineFreeVars,
- varTypeTyVars,
+ varTypeTyVars, varTypeTcTyVars,
+ idUnfoldingVars, idFreeVars, idRuleAndUnfoldingVars,
+ idRuleVars, idRuleRhsVars,
ruleRhsFreeVars, rulesFreeVars,
ruleLhsFreeNames, ruleLhsFreeIds,
---------
rhs_fvs :: (Id,CoreExpr) -> FV
-rhs_fvs (bndr, rhs) = expr_fvs rhs `union` someVars (bndrRuleVars bndr)
+rhs_fvs (bndr, rhs) = expr_fvs rhs `union`
+ someVars (bndrRuleAndUnfoldingVars bndr)
-- Treat any RULES as extra RHSs of the binding
---------
-- | Those variables free in the both the left right hand sides of a rule
ruleFreeVars :: CoreRule -> VarSet
+ruleFreeVars (BuiltinRule {}) = noFVs
ruleFreeVars (Rule { ru_fn = fn, ru_bndrs = bndrs, ru_rhs = rhs, ru_args = args })
= delFromUFM fvs fn -- Note [Rule free var hack]
where
-- (b `delBinderFV` s) removes the binder b from the free variable set s,
-- but *adds* to s
--- (a) the free variables of b's type
--- (b) the idSpecVars of b
+--
+-- the free variables of b's type
--
-- This is really important for some lambdas:
-- In (\x::a -> x) the only mention of "a" is in the binder.
| isLocalId var || isCoVar var = tyVarsOfType (idType var)
| otherwise = emptyVarSet -- Global Ids and non-coercion TyVars
-idFreeVars :: Id -> VarSet
-idFreeVars id = ASSERT( isId id) idRuleVars id `unionVarSet` varTypeTyVars id
-
-bndrRuleVars ::Var -> VarSet
-bndrRuleVars v | isTyVar v = emptyVarSet
- | otherwise = idRuleVars v
-
-idRuleVars ::Id -> VarSet
-idRuleVars id = ASSERT( isId id)
- specInfoFreeVars (idSpecialisation id) `unionVarSet`
- idInlineFreeVars id -- And the variables in an INLINE rule
+varTypeTcTyVars :: Var -> TyVarSet
+-- Find the type variables free in the type of the variable
+-- Remember, coercion variables can mention type variables...
+varTypeTcTyVars var
+ | isLocalId var || isCoVar var = tcTyVarsOfType (idType var)
+ | otherwise = emptyVarSet -- Global Ids and non-coercion TyVars
-idRuleRhsVars :: Id -> VarSet
+idFreeVars :: Id -> VarSet
+-- Type variables, rule variables, and inline variables
+idFreeVars id = ASSERT( isId id)
+ varTypeTyVars id `unionVarSet`
+ idRuleAndUnfoldingVars id
+
+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
+ | otherwise = idRuleAndUnfoldingVars v
+
+idRuleAndUnfoldingVars :: Id -> VarSet
+idRuleAndUnfoldingVars id = ASSERT( isId id)
+ idRuleVars id `unionVarSet`
+ idUnfoldingVars id
+
+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)
- (idInlineFreeVars id)
+ emptyVarSet
(idCoreRules id)
-idInlineFreeVars :: Id -> VarSet
--- Produce free vars for an InlineRule, BUT NOT for an ordinary unfolding
--- An InlineRule behaves *very like* a RULE, and that is what we are after here
-idInlineFreeVars id
- = case idUnfolding id of
- InlineRule { uf_tmpl = tmpl } -> exprFreeVars tmpl
- _ -> emptyVarSet
+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
+-- 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
+ = case realIdUnfolding id of
+ CoreUnfolding { uf_tmpl = rhs, uf_guidance = InlineRule {} }
+ -> exprFreeVars rhs
+ DFunUnfolding _ args -> exprsFreeVars args
+ _ -> emptyVarSet
\end{code}
rhs2 = freeVars rhs
freeVars (Let (NonRec binder rhs) body)
- = (freeVarsOf rhs2 `unionFVs` body_fvs `unionFVs` bndrRuleVars binder,
+ = (freeVarsOf rhs2
+ `unionFVs` body_fvs
+ `unionFVs` bndrRuleAndUnfoldingVars binder,
-- Remember any rules; cf rhs_fvs above
AnnLet (AnnNonRec binder rhs2) body2)
where
rhss2 = map freeVars rhss
rhs_body_fvs = foldr (unionFVs . freeVarsOf) body_fvs rhss2
- all_fvs = foldr (unionFVs . idRuleVars) rhs_body_fvs binders
+ all_fvs = foldr (unionFVs . idRuleAndUnfoldingVars) rhs_body_fvs binders
-- The "delBinderFV" happens after adding the idSpecVars,
-- since the latter may add some of the binders as fvs