%
+% (c) The University of Glasgow 2006
% (c) The AQUA Project, Glasgow University, 1996-1998
%
+This module contains "tidying" code for *nested* expressions, bindings, rules.
+The code for *top-level* bindings is in TidyPgm.
+
\begin{code}
module CoreTidy (
tidyExpr, tidyVarOcc, tidyRule, tidyRules
#include "HsVersions.h"
import CoreSyn
-import CoreUtils ( exprArity )
-import Unify ( coreRefineTys )
-import DataCon ( DataCon, isVanillaDataCon )
-import Id ( Id, mkUserLocal, idInfo, setIdInfo, idUnique,
- idType, setIdType )
-import IdInfo ( setArityInfo, vanillaIdInfo,
- newStrictnessInfo, setAllStrictnessInfo,
- newDemandInfo, setNewDemandInfo )
-import Type ( Type, tidyType, tidyTyVarBndr, substTy, mkOpenTvSubst )
-import Var ( Var, TyVar, varName )
+import CoreArity
+import Id
+import IdInfo
+import Type
+import Var
import VarEnv
-import UniqFM ( lookupUFM )
-import Name ( Name, getOccName )
-import OccName ( tidyOccName )
-import SrcLoc ( noSrcLoc )
-import Maybes ( orElse )
-import Outputable
-import Util ( mapAccumL )
+import UniqFM
+import Name hiding (tidyNameOcc)
+import SrcLoc
+import Maybes
+
+import Data.List
\end{code}
-This module contains "tidying" code for *nested* expressions, bindings, rules.
-The code for *top-level* bindings is in TidyPgm.
-
%************************************************************************
%* *
\subsection{Tidying expressions, rules}
------------ Expressions --------------
tidyExpr :: TidyEnv -> CoreExpr -> CoreExpr
-tidyExpr env (Var v) = Var (tidyVarOcc env v)
-tidyExpr env (Type ty) = Type (tidyType env ty)
-tidyExpr env (Lit lit) = Lit lit
-tidyExpr env (App f a) = App (tidyExpr env f) (tidyExpr env a)
-tidyExpr env (Note n e) = Note (tidyNote env n) (tidyExpr env e)
+tidyExpr env (Var v) = Var (tidyVarOcc env v)
+tidyExpr env (Type ty) = Type (tidyType env ty)
+tidyExpr _ (Lit lit) = Lit lit
+tidyExpr env (App f a) = App (tidyExpr env f) (tidyExpr env a)
+tidyExpr env (Note n e) = Note (tidyNote env n) (tidyExpr env e)
+tidyExpr env (Cast e co) = Cast (tidyExpr env e) (tidyType env co)
tidyExpr env (Let b e)
= tidyBind env b =: \ (env', b') ->
Lam b (tidyExpr env' e)
------------ Case alternatives --------------
-tidyAlt case_bndr env (DataAlt con, vs, rhs)
- | not (isVanillaDataCon con) -- GADT case
- = tidyBndrs env tvs =: \ (env1, tvs') ->
- let
- env2 = refineTidyEnv env con tvs' scrut_ty
- in
- tidyBndrs env2 ids =: \ (env3, ids') ->
- (DataAlt con, tvs' ++ ids', tidyExpr env3 rhs)
- where
- (tvs, ids) = span isTyVar vs
- scrut_ty = idType case_bndr
-
-tidyAlt case_bndr env (con, vs, rhs)
+tidyAlt :: CoreBndr -> TidyEnv -> CoreAlt -> CoreAlt
+tidyAlt _case_bndr env (con, vs, rhs)
= tidyBndrs env vs =: \ (env', vs) ->
(con, vs, tidyExpr env' rhs)
-refineTidyEnv :: TidyEnv -> DataCon -> [TyVar] -> Type -> TidyEnv
--- Refine the TidyEnv in the light of the type refinement from coreRefineTys
-refineTidyEnv tidy_env@(occ_env, var_env) con tvs scrut_ty
- = case coreRefineTys con tvs scrut_ty of
- Nothing -> tidy_env
- Just (tv_subst, all_bound_here)
- | all_bound_here -- Local type refinement only
- -> tidy_env
- | otherwise -- Apply the refining subst to the tidy env
- -- This ensures that occurences have the most refined type
- -- And that means that exprType will work right everywhere
- -> (occ_env, mapVarEnv (refine subst) var_env)
- where
- subst = mkOpenTvSubst tv_subst
- where
- refine subst var | isId var = setIdType var (substTy subst (idType var))
- | otherwise = var
-
------------ Notes --------------
-tidyNote env (Coerce t1 t2) = Coerce (tidyType env t1) (tidyType env t2)
-tidyNote env note = note
+tidyNote :: TidyEnv -> Note -> Note
+tidyNote _ note = note
------------ Rules --------------
tidyRules :: TidyEnv -> [CoreRule] -> [CoreRule]
-tidyRules env [] = []
+tidyRules _ [] = []
tidyRules env (rule : rules)
= tidyRule env rule =: \ rule ->
tidyRules env rules =: \ rules ->
(rule : rules)
tidyRule :: TidyEnv -> CoreRule -> CoreRule
-tidyRule env rule@(BuiltinRule {}) = rule
+tidyRule _ rule@(BuiltinRule {}) = rule
tidyRule env rule@(Rule { ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs,
ru_fn = fn, ru_rough = mb_ns })
= tidyBndrs env bndrs =: \ (env', bndrs) ->
-- Fortunately, we can lookup in the VarEnv with a name
tidyNameOcc (_, var_env) n = case lookupUFM var_env n of
Nothing -> n
- Just v -> varName v
+ Just v -> idName v
tidyVarOcc :: TidyEnv -> Var -> Var
tidyVarOcc (_, var_env) v = lookupVarEnv var_env v `orElse` v
-- CorePrep to turn the let into a case.
--
-- Similarly arity info for eta expansion in CorePrep
- --
+ --
+ -- Set inline-prag info so that we preseve it across
+ -- separate compilation boundaries
final_id = new_id `setIdInfo` new_info
idinfo = idInfo id
- new_info = vanillaIdInfo
+ new_info = idInfo new_id
`setArityInfo` exprArity rhs
- `setAllStrictnessInfo` newStrictnessInfo idinfo
- `setNewDemandInfo` newDemandInfo idinfo
+ `setStrictnessInfo` strictnessInfo idinfo
+ `setDemandInfo` demandInfo idinfo
+ `setInlinePragInfo` inlinePragInfo idinfo
-- Override the env we get back from tidyId with the new IdInfo
-- so it gets propagated to the usage sites.
-- Non-top-level variables
tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
tidyIdBndr env@(tidy_env, var_env) id
- = -- do this pattern match strictly, otherwise we end up holding on to
+ = -- Do this pattern match strictly, otherwise we end up holding on to
-- stuff in the OccName.
case tidyOccName tidy_env (getOccName id) of { (tidy_env', occ') ->
let
-- The SrcLoc isn't important now,
-- though we could extract it from the Id
--
- -- All nested Ids now have the same IdInfo, namely vanillaIdInfo,
- -- which should save some space.
- -- But note that tidyLetBndr puts some of it back.
- ty' = tidyType env (idType id)
- id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc
- `setIdInfo` vanillaIdInfo
- var_env' = extendVarEnv var_env id id'
+ ty' = tidyType env (idType id)
+ name' = mkInternalName (idUnique id) occ' noSrcSpan
+ id' = mkLocalIdWithInfo name' ty' new_info
+ var_env' = extendVarEnv var_env id id'
+
+ -- Note [Tidy IdInfo]
+ new_info = vanillaIdInfo `setOccInfo` occInfo old_info
+ old_info = idInfo id
in
- ((tidy_env', var_env'), id')
+ ((tidy_env', var_env'), id')
}
\end{code}
+Note [Tidy IdInfo]
+~~~~~~~~~~~~~~~~~~
+All nested Ids now have the same IdInfo, namely vanillaIdInfo, which
+should save some space; except that we preserve occurrence info for
+two reasons:
+
+ (a) To make printing tidy core nicer
+
+ (b) Because we tidy RULES and InlineRules, which may then propagate
+ via --make into the compilation of the next module, and we want
+ the benefit of that occurrence analysis when we use the rule or
+ or inline the function. In particular, it's vital not to lose
+ loop-breaker info, else we get an infinite inlining loop
+
+Note that tidyLetBndr puts more IdInfo back.
+
+
\begin{code}
+(=:) :: a -> (a -> b) -> b
m =: k = m `seq` k m
\end{code}