Utility functions on @Core@ syntax
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module CoreSubst (
-- Substitution stuff
Subst, TvSubstEnv, IdSubstEnv, InScopeSet,
import PprCore () -- Instances
import Util
import FastTypes
+
+import Data.List
\end{code}
substIdBndr :: Subst -- Substitution to use for the IdInfo
-> Subst -> Id -- Substitition and Id to transform
-> (Subst, Id) -- Transformed pair
+ -- NB: unfolding may be zapped
substIdBndr rec_subst subst@(Subst in_scope env tvs) old_id
= (Subst (in_scope `extendInScopeSet` new_id) new_env tvs, new_id)
-- The lazy-set is because we're in a loop here, with
-- rec_subst, when dealing with a mutually-recursive group
new_id = maybeModifyIdInfo mb_new_info id2
- mb_new_info = substIdInfo rec_subst (idInfo id2)
+ mb_new_info = substIdInfo rec_subst id2 (idInfo id2)
+ -- NB: unfolding info may be zapped
-- Extend the substitution if the unique has changed
-- See the notes with substTyVarBndr for the delVarEnv
where
id1 = setVarUnique old_id uniq
id2 = substIdType subst id1
- new_id = maybeModifyIdInfo (substIdInfo rec_subst (idInfo old_id)) id2
+ new_id = maybeModifyIdInfo (substIdInfo rec_subst id2 (idInfo old_id)) id2
new_env = extendVarEnv env old_id (Var new_id)
\end{code}
old_ty = idType id
------------------
-substIdInfo :: Subst -> IdInfo -> Maybe IdInfo
+substIdInfo :: Subst -> Id -> IdInfo -> Maybe IdInfo
-- Always zaps the unfolding, to save substitution work
-substIdInfo subst info
+substIdInfo subst new_id info
| nothing_to_do = Nothing
- | otherwise = Just (info `setSpecInfo` substSpec subst old_rules
+ | otherwise = Just (info `setSpecInfo` substSpec subst new_id old_rules
`setWorkerInfo` substWorker subst old_wrkr
`setUnfoldingInfo` noUnfolding)
where
-- via postInlineUnconditionally, hence warning)
------------------
-substSpec :: Subst -> SpecInfo -> SpecInfo
+substSpec :: Subst -> Id -> SpecInfo -> SpecInfo
-substSpec subst spec@(SpecInfo rules rhs_fvs)
+substSpec subst new_fn spec@(SpecInfo rules rhs_fvs)
| isEmptySubst subst
= spec
| otherwise
= seqSpecInfo new_rules `seq` new_rules
where
+ new_name = idName new_fn
new_rules = SpecInfo (map do_subst rules) (substVarSet subst rhs_fvs)
do_subst rule@(BuiltinRule {}) = rule
do_subst rule@(Rule { ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs })
- = rule { ru_bndrs = bndrs',
+ = rule { ru_bndrs = bndrs',
+ ru_fn = new_name, -- Important: the function may have changed its name!
ru_args = map (substExpr subst') args,
ru_rhs = substExpr subst' rhs }
where