%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
+% (c) The AQUA Project, Glasgow University, 1996-1998
%
-\section{Tidying up Core}
\begin{code}
module CoreTidy (
- tidyCorePgm, tidyExpr, tidyCoreExpr,
- tidyBndr, tidyBndrs
+ tidyExpr, tidyVarOcc, tidyRule, tidyRules
) where
#include "HsVersions.h"
-import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
import CoreSyn
-import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
-import CoreFVs ( ruleSomeFreeVars, exprSomeFreeVars )
-import PprCore ( pprIdCoreRule )
-import CoreLint ( showPass, endPass )
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 VarEnv
-import VarSet
-import Var ( Id, Var )
-import Id ( idType, idInfo, idName, isExportedId,
- idSpecialisation, idUnique,
- mkVanillaGlobal, isLocalId,
- isImplicitId, mkUserLocal, setIdInfo
- )
-import IdInfo {- loads of stuff -}
-import NewDemand ( isBottomingSig, topSig )
-import BasicTypes ( isNeverActive )
-import Name ( getOccName, nameOccName, mkLocalName, mkGlobalName,
- localiseName, isGlobalName, nameSrcLoc
- )
-import NameEnv ( filterNameEnv )
-import OccName ( TidyOccEnv, initTidyOccEnv, tidyOccName )
-import Type ( tidyTopType, tidyType, tidyTyVarBndr )
-import Module ( Module, moduleName )
-import HscTypes ( PersistentCompilerState( pcs_PRS ),
- PersistentRenamerState( prsOrig ),
- NameSupply( nsNames, nsUniqs ),
- TypeEnv, extendTypeEnvList, typeEnvIds,
- ModDetails(..), TyThing(..)
- )
-import FiniteMap ( lookupFM, addToFM )
-import Maybes ( orElse )
-import ErrUtils ( showPass, dumpIfSet_core )
+import UniqFM ( lookupUFM )
+import Name ( Name, getOccName )
+import OccName ( tidyOccName )
import SrcLoc ( noSrcLoc )
-import UniqFM ( mapUFM )
-import UniqSupply ( splitUniqSupply, uniqFromSupply )
-import List ( partition )
-import Util ( mapAccumL )
-import Maybe ( isJust )
+import Maybes ( orElse )
import Outputable
+import Util ( mapAccumL )
\end{code}
-
-%************************************************************************
-%* *
-\subsection{What goes on}
-%* *
-%************************************************************************
-
-[SLPJ: 19 Nov 00]
-
-The plan is this.
-
-Step 1: Figure out external Ids
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-First we figure out which Ids are "external" Ids. An
-"external" Id is one that is visible from outside the compilation
-unit. These are
- a) the user exported ones
- b) ones mentioned in the unfoldings, workers,
- or rules of externally-visible ones
-This exercise takes a sweep of the bindings bottom to top. Actually,
-in Step 2 we're also going to need to know which Ids should be
-exported with their unfoldings, so we produce not an IdSet but an
-IdEnv Bool
-
-
-Step 2: Tidy the program
-~~~~~~~~~~~~~~~~~~~~~~~~
-Next we traverse the bindings top to bottom. For each *top-level*
-binder
-
- 1. Make it into a GlobalId
-
- 2. Give it a system-wide Unique.
- [Even non-exported things need system-wide Uniques because the
- byte-code generator builds a single Name->BCO symbol table.]
-
- We use the NameSupply kept in the PersistentRenamerState as the
- source of such system-wide uniques.
-
- For external Ids, use the original-name cache in the NameSupply
- to ensure that the unique assigned is the same as the Id had
- in any previous compilation run.
-
- 3. If it's an external Id, make it have a global Name, otherwise
- make it have a local Name.
- This is used by the code generator to decide whether
- to make the label externally visible
-
- 4. Give external Ids a "tidy" occurrence name. This means
- we can print them in interface files without confusing
- "x" (unique 5) with "x" (unique 10).
-
- 5. Give it its UTTERLY FINAL IdInfo; in ptic,
- * Its IdDetails becomes VanillaGlobal, reflecting the fact that
- from now on we regard it as a global, not local, Id
-
- * its unfolding, if it should have one
-
- * its arity, computed from the number of visible lambdas
-
- * its CAF info, computed from what is free in its RHS
-
-
-Finally, substitute these new top-level binders consistently
-throughout, including in unfoldings. We also tidy binders in
-RHSs, so that they print nicely in interfaces.
-
-\begin{code}
-tidyCorePgm :: DynFlags -> Module
- -> PersistentCompilerState
- -> CgInfoEnv -- Information from the back end,
- -- to be splatted into the IdInfo
- -> ModDetails
- -> IO (PersistentCompilerState, ModDetails)
-
-tidyCorePgm dflags mod pcs cg_info_env
- (ModDetails { md_types = env_tc, md_insts = insts_tc,
- md_binds = binds_in, md_rules = orphans_in })
- = do { showPass dflags "Tidy Core"
-
- ; let ext_ids = findExternalSet binds_in orphans_in
- ; let ext_rules = findExternalRules binds_in orphans_in ext_ids
-
- -- We also make sure to avoid any exported binders. Consider
- -- f{-u1-} = 1 -- Local decl
- -- ...
- -- f{-u2-} = 2 -- Exported decl
- --
- -- The second exported decl must 'get' the name 'f', so we
- -- have to put 'f' in the avoids list before we get to the first
- -- decl. tidyTopId then does a no-op on exported binders.
- ; let prs = pcs_PRS pcs
- orig_ns = prsOrig prs
-
- init_tidy_env = (orig_ns, initTidyOccEnv avoids, emptyVarEnv)
- avoids = [getOccName name | bndr <- typeEnvIds env_tc,
- let name = idName bndr,
- isGlobalName name]
- -- In computing our "avoids" list, we must include
- -- all implicit Ids
- -- all things with global names (assigned once and for
- -- all by the renamer)
- -- since their names are "taken".
- -- The type environment is a convenient source of such things.
-
- ; let ((orig_ns', occ_env, subst_env), tidy_binds)
- = mapAccumL (tidyTopBind mod ext_ids cg_info_env)
- init_tidy_env binds_in
-
- ; let tidy_rules = tidyIdRules (occ_env,subst_env) ext_rules
-
- ; let prs' = prs { prsOrig = orig_ns' }
- pcs' = pcs { pcs_PRS = prs' }
-
- ; let final_ids = [ id
- | bind <- tidy_binds
- , id <- bindersOf bind
- , isGlobalName (idName id)]
-
- -- Dfuns are local Ids that might have
- -- changed their unique during tidying
- ; let lookup_dfun_id id = lookupVarEnv subst_env id `orElse`
- pprPanic "lookup_dfun_id" (ppr id)
-
-
- ; let tidy_type_env = mkFinalTypeEnv env_tc final_ids
- tidy_dfun_ids = map lookup_dfun_id insts_tc
-
- ; let tidy_details = ModDetails { md_types = tidy_type_env,
- md_rules = tidy_rules,
- md_insts = tidy_dfun_ids,
- md_binds = tidy_binds }
-
- ; endPass dflags "Tidy Core" Opt_D_dump_simpl tidy_binds
- ; dumpIfSet_core dflags Opt_D_dump_simpl
- "Tidy Core Rules"
- (vcat (map pprIdCoreRule tidy_rules))
-
- ; return (pcs', tidy_details)
- }
-
-tidyCoreExpr :: CoreExpr -> IO CoreExpr
-tidyCoreExpr expr = return (tidyExpr emptyTidyEnv expr)
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Write a new interface file}
-%* *
-%************************************************************************
-
-\begin{code}
-mkFinalTypeEnv :: TypeEnv -- From typechecker
- -> [Id] -- Final Ids
- -> TypeEnv
-
-mkFinalTypeEnv type_env final_ids
- = extendTypeEnvList (filterNameEnv keep_it type_env)
- (map AnId final_ids)
- where
- -- The competed type environment is gotten from
- -- a) keeping the types and classes
- -- b) removing all Ids,
- -- c) adding Ids with correct IdInfo, including unfoldings,
- -- gotten from the bindings
- -- From (c) we keep only those Ids with Global names;
- -- the CoreTidy pass makes sure these are all and only
- -- the externally-accessible ones
- -- This truncates the type environment to include only the
- -- exported Ids and things needed from them, which saves space
- --
- -- However, we do keep things like constructors, which should not appear
- -- in interface files, because they are needed by importing modules when
- -- using the compilation manager
-
- -- We keep implicit Ids, because they won't appear
- -- in the bindings from which final_ids are derived!
- keep_it (AnId id) = isImplicitId id -- Remove all Ids except implicit ones
- keep_it other = True -- Keep all TyCons and Classes
-\end{code}
-
-\begin{code}
-findExternalRules :: [CoreBind]
- -> [IdCoreRule] -- Orphan rules
- -> IdEnv a -- Ids that are exported, so we need their rules
- -> [IdCoreRule]
- -- The complete rules are gotten by combining
- -- a) the orphan rules
- -- b) rules embedded in the top-level Ids
-findExternalRules binds orphan_rules ext_ids
- | opt_OmitInterfacePragmas = []
- | otherwise
- = orphan_rules ++ local_rules
- where
- local_rules = [ (id, rule)
- | id <- bindersOfBinds binds,
- id `elemVarEnv` ext_ids,
- rule <- rulesRules (idSpecialisation id),
- not (isBuiltinRule rule)
- -- We can't print builtin rules in interface files
- -- Since they are built in, an importing module
- -- will have access to them anyway
- ]
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Step 1: finding externals}
-%* *
-%************************************************************************
-
-\begin{code}
-findExternalSet :: [CoreBind] -> [IdCoreRule]
- -> IdEnv Bool -- In domain => external
- -- Range = True <=> show unfolding
- -- Step 1 from the notes above
-findExternalSet binds orphan_rules
- = foldr find init_needed binds
- where
- orphan_rule_ids :: IdSet
- orphan_rule_ids = unionVarSets [ ruleSomeFreeVars isLocalId rule
- | (_, rule) <- orphan_rules]
- init_needed :: IdEnv Bool
- init_needed = mapUFM (\_ -> False) orphan_rule_ids
- -- The mapUFM is a bit cheesy. It is a cheap way
- -- to turn the set of orphan_rule_ids, which we use to initialise
- -- the sweep, into a mapping saying 'don't expose unfolding'
- -- (When we come to the binding site we may change our mind, of course.)
-
- find (NonRec id rhs) needed
- | need_id needed id = addExternal (id,rhs) needed
- | otherwise = needed
- find (Rec prs) needed = find_prs prs needed
-
- -- For a recursive group we have to look for a fixed point
- find_prs prs needed
- | null needed_prs = needed
- | otherwise = find_prs other_prs new_needed
- where
- (needed_prs, other_prs) = partition (need_pr needed) prs
- new_needed = foldr addExternal needed needed_prs
-
- -- The 'needed' set contains the Ids that are needed by earlier
- -- interface file emissions. If the Id isn't in this set, and isn't
- -- exported, there's no need to emit anything
- need_id needed_set id = id `elemVarEnv` needed_set || isExportedId id
- need_pr needed_set (id,rhs) = need_id needed_set id
-
-addExternal :: (Id,CoreExpr) -> IdEnv Bool -> IdEnv Bool
--- The Id is needed; extend the needed set
--- with it and its dependents (free vars etc)
-addExternal (id,rhs) needed
- = extendVarEnv (foldVarSet add_occ needed new_needed_ids)
- id show_unfold
- where
- add_occ id needed = extendVarEnv needed id False
- -- "False" because we don't know we need the Id's unfolding
- -- We'll override it later when we find the binding site
-
- new_needed_ids | opt_OmitInterfacePragmas = emptyVarSet
- | otherwise = worker_ids `unionVarSet`
- unfold_ids `unionVarSet`
- spec_ids
-
- idinfo = idInfo id
- dont_inline = isNeverActive (inlinePragInfo idinfo)
- loop_breaker = isLoopBreaker (occInfo idinfo)
- bottoming_fn = isBottomingSig (newStrictnessInfo idinfo `orElse` topSig)
- spec_ids = rulesRhsFreeVars (specInfo idinfo)
- worker_info = workerInfo idinfo
-
- -- Stuff to do with the Id's unfolding
- -- The simplifier has put an up-to-date unfolding
- -- in the IdInfo, but the RHS will do just as well
- unfolding = unfoldingInfo idinfo
- rhs_is_small = not (neverUnfold unfolding)
-
- -- We leave the unfolding there even if there is a worker
- -- In GHCI the unfolding is used by importers
- -- When writing an interface file, we omit the unfolding
- -- if there is a worker
- show_unfold = not bottoming_fn && -- Not necessary
- not dont_inline &&
- not loop_breaker &&
- rhs_is_small && -- Small enough
- okToUnfoldInHiFile rhs -- No casms etc
-
- unfold_ids | show_unfold = exprSomeFreeVars isLocalId rhs
- | otherwise = emptyVarSet
-
- worker_ids = case worker_info of
- HasWorker work_id _ -> unitVarSet work_id
- otherwise -> emptyVarSet
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Step 2: top-level tidying}
-%* *
-%************************************************************************
-
-
-\begin{code}
-type TopTidyEnv = (NameSupply, TidyOccEnv, VarEnv Var)
-
--- TopTidyEnv: when tidying we need to know
--- * ns: The NameSupply, containing a unique supply and any pre-ordained Names.
--- These may have arisen because the
--- renamer read in an interface file mentioning M.$wf, say,
--- and assigned it unique r77. If, on this compilation, we've
--- invented an Id whose name is $wf (but with a different unique)
--- we want to rename it to have unique r77, so that we can do easy
--- comparisons with stuff from the interface file
---
--- * occ_env: The TidyOccEnv, which tells us which local occurrences
--- are 'used'
---
--- * subst_env: A Var->Var mapping that substitutes the new Var for the old
-\end{code}
-
-
-\begin{code}
-tidyTopBind :: Module
- -> IdEnv Bool -- Domain = Ids that should be external
- -- True <=> their unfolding is external too
- -> CgInfoEnv
- -> TopTidyEnv -> CoreBind
- -> (TopTidyEnv, CoreBind)
-
-tidyTopBind mod ext_ids cg_info_env top_tidy_env (NonRec bndr rhs)
- = ((orig,occ,subst) , NonRec bndr' rhs')
- where
- ((orig,occ,subst), bndr')
- = tidyTopBinder mod ext_ids cg_info_env
- rec_tidy_env rhs rhs' top_tidy_env bndr
- rec_tidy_env = (occ,subst)
- rhs' = tidyExpr rec_tidy_env rhs
-
-tidyTopBind mod ext_ids cg_info_env top_tidy_env (Rec prs)
- = (final_env, Rec prs')
- where
- (final_env@(_,occ,subst), prs') = mapAccumL do_one top_tidy_env prs
- rec_tidy_env = (occ,subst)
-
- do_one top_tidy_env (bndr,rhs)
- = ((orig,occ,subst), (bndr',rhs'))
- where
- ((orig,occ,subst), bndr')
- = tidyTopBinder mod ext_ids cg_info_env
- rec_tidy_env rhs rhs' top_tidy_env bndr
-
- rhs' = tidyExpr rec_tidy_env rhs
-
-tidyTopBinder :: Module -> IdEnv Bool -> CgInfoEnv
- -> TidyEnv -- The TidyEnv is used to tidy the IdInfo
- -> CoreExpr -- RHS *before* tidying
- -> CoreExpr -- RHS *after* tidying
- -- The TidyEnv and the after-tidying RHS are
- -- both are knot-tied: don't look at them!
- -> TopTidyEnv -> Id -> (TopTidyEnv, Id)
- -- NB: tidyTopBinder doesn't affect the unique supply
-
-tidyTopBinder mod ext_ids cg_info_env rec_tidy_env rhs tidy_rhs
- env@(ns2, occ_env2, subst_env2) id
- -- This function is the heart of Step 2
- -- The rec_tidy_env is the one to use for the IdInfo
- -- It's necessary because when we are dealing with a recursive
- -- group, a variable late in the group might be mentioned
- -- in the IdInfo of one early in the group
-
- -- The rhs is already tidied
-
- = ((orig_env', occ_env', subst_env'), id')
- where
- (orig_env', occ_env', name') = tidyTopName mod ns2 occ_env2
- is_external
- (idName id)
- ty' = tidyTopType (idType id)
- idinfo = tidyTopIdInfo rec_tidy_env is_external
- (idInfo id) unfold_info arity
- (lookupCgInfo cg_info_env name')
-
- id' = mkVanillaGlobal name' ty' idinfo
-
- subst_env' = extendVarEnv subst_env2 id id'
-
- maybe_external = lookupVarEnv ext_ids id
- is_external = isJust maybe_external
-
- -- Expose an unfolding if ext_ids tells us to
- -- Remember that ext_ids maps an Id to a Bool:
- -- True to show the unfolding, False to hide it
- show_unfold = maybe_external `orElse` False
- unfold_info | show_unfold = mkTopUnfolding tidy_rhs
- | otherwise = noUnfolding
-
- -- Usually the Id will have an accurate arity on it, because
- -- the simplifier has just run, but not always.
- -- One case I found was when the last thing the simplifier
- -- did was to let-bind a non-atomic argument and then float
- -- it to the top level. So it seems more robust just to
- -- fix it here.
- arity = exprArity rhs
-
-
-
--- tidyTopIdInfo creates the final IdInfo for top-level
--- binders. There are two delicate pieces:
---
--- * Arity. After CoreTidy, this arity must not change any more.
--- Indeed, CorePrep must eta expand where necessary to make
--- the manifest arity equal to the claimed arity.
---
--- * CAF info, which comes from the CoreToStg pass via a knot.
--- The CAF info will not be looked at by the downstream stuff:
--- it *generates* it, and knot-ties it back. It will only be
--- looked at by (a) MkIface when generating an interface file
--- (b) In GHCi, importing modules
--- Nevertheless, we add the info here so that it propagates to all
--- occurrences of the binders in RHSs, and hence to occurrences in
--- unfoldings, which are inside Ids imported by GHCi. Ditto RULES.
---
--- An alterative would be to do a second pass over the unfoldings
--- of Ids, and rules, right at the top, but that would be a pain.
-
-tidyTopIdInfo tidy_env is_external idinfo unfold_info arity cg_info
- | opt_OmitInterfacePragmas || not is_external
- -- Only basic info if the Id isn't external, or if we don't have -O
- = basic_info
-
- | otherwise -- Add extra optimisation info
- = basic_info
- `setInlinePragInfo` inlinePragInfo idinfo
- `setUnfoldingInfo` unfold_info
- `setWorkerInfo` tidyWorker tidy_env (workerInfo idinfo)
- -- NB: we throw away the Rules
- -- They have already been extracted by findExternalRules
-
- where
- -- baasic_info is attached to every top-level binder
- basic_info = vanillaIdInfo
- `setCgInfo` cg_info
- `setArityInfo` arity
- `setNewStrictnessInfo` newStrictnessInfo idinfo
-
--- This is where we set names to local/global based on whether they really are
--- externally visible (see comment at the top of this module). If the name
--- was previously local, we have to give it a unique occurrence name if
--- we intend to globalise it.
-tidyTopName mod ns occ_env external name
- | global && internal = (ns, occ_env, localiseName name)
-
- | global && external = (ns, occ_env, name)
- -- Global names are assumed to have been allocated by the renamer,
- -- so they already have the "right" unique
- -- And it's a system-wide unique too
-
- | local && internal = (ns_w_local, occ_env', new_local_name)
- -- Even local, internal names must get a unique occurrence, because
- -- if we do -split-objs we globalise the name later, in the code generator
- --
- -- Similarly, we must make sure it has a system-wide Unique, because
- -- the byte-code generator builds a system-wide Name->BCO symbol table
-
- | local && external = case lookupFM ns_names key of
- Just orig -> (ns, occ_env', orig)
- Nothing -> (ns_w_global, occ_env', new_global_name)
- -- If we want to globalise a currently-local name, check
- -- whether we have already assigned a unique for it.
- -- If so, use it; if not, extend the table (ns_w_global).
- -- This is needed when *re*-compiling a module in GHCi; we want to
- -- use the same name for externally-visible things as we did before.
-
- where
- global = isGlobalName name
- local = not global
- internal = not external
-
- (occ_env', occ') = tidyOccName occ_env (nameOccName name)
- key = (moduleName mod, occ')
- ns_names = nsNames ns
- ns_uniqs = nsUniqs ns
- (us1, us2) = splitUniqSupply ns_uniqs
- uniq = uniqFromSupply us1
- loc = nameSrcLoc name
-
- new_local_name = mkLocalName uniq occ' loc
- new_global_name = mkGlobalName uniq mod occ' loc
-
- ns_w_local = ns { nsUniqs = us2 }
- ns_w_global = ns { nsUniqs = us2, nsNames = addToFM ns_names key new_global_name }
-
-
------------- Worker --------------
-tidyWorker tidy_env (HasWorker work_id wrap_arity)
- = HasWorker (tidyVarOcc tidy_env work_id) wrap_arity
-tidyWorker tidy_env other
- = NoWorker
-
------------- Rules --------------
-tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule]
-tidyIdRules env [] = []
-tidyIdRules env ((fn,rule) : rules)
- = tidyRule env rule =: \ rule ->
- tidyIdRules env rules =: \ rules ->
- ((tidyVarOcc env fn, rule) : rules)
-
-tidyRule :: TidyEnv -> CoreRule -> CoreRule
-tidyRule env rule@(BuiltinRule _ _) = rule
-tidyRule env (Rule name act vars tpl_args rhs)
- = tidyBndrs env vars =: \ (env', vars) ->
- map (tidyExpr env') tpl_args =: \ tpl_args ->
- (Rule name act vars tpl_args (tidyExpr env' rhs))
-\end{code}
+This module contains "tidying" code for *nested* expressions, bindings, rules.
+The code for *top-level* bindings is in TidyPgm.
%************************************************************************
%* *
-\subsection{Step 2: inner tidying
+\subsection{Tidying expressions, rules}
%* *
%************************************************************************
-> (TidyEnv, CoreBind)
tidyBind env (NonRec bndr rhs)
- = tidyLetBndr env (bndr,rhs) =: \ (env', bndr') ->
+ = tidyLetBndr env (bndr,rhs) =: \ (env', bndr') ->
(env', NonRec bndr' (tidyExpr env' rhs))
tidyBind env (Rec prs)
- = mapAccumL tidyLetBndr env prs =: \ (env', bndrs') ->
+ = mapAccumL tidyLetBndr env prs =: \ (env', bndrs') ->
map (tidyExpr env') (map snd prs) =: \ rhss' ->
(env', Rec (zip bndrs' rhss'))
+------------ 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
= tidyBind env b =: \ (env', b') ->
Let b' (tidyExpr env' e)
-tidyExpr env (Case e b alts)
+tidyExpr env (Case e b ty alts)
= tidyBndr env b =: \ (env', b) ->
- Case (tidyExpr env e) b (map (tidyAlt env') alts)
+ Case (tidyExpr env e) b (tidyType env ty)
+ (map (tidyAlt b env') alts)
tidyExpr env (Lam b e)
= tidyBndr 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 env (con, vs, rhs)
+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
+
+------------ Rules --------------
+tidyRules :: TidyEnv -> [CoreRule] -> [CoreRule]
+tidyRules env [] = []
+tidyRules env (rule : rules)
+ = tidyRule env rule =: \ rule ->
+ tidyRules env rules =: \ rules ->
+ (rule : rules)
+
+tidyRule :: TidyEnv -> CoreRule -> CoreRule
+tidyRule env 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) ->
+ map (tidyExpr env') args =: \ args ->
+ rule { ru_bndrs = bndrs, ru_args = args,
+ ru_rhs = tidyExpr env' rhs,
+ ru_fn = tidyNameOcc env fn,
+ ru_rough = map (fmap (tidyNameOcc env')) mb_ns }
\end{code}
%************************************************************************
%* *
-\subsection{Tidying up non-top-level binders}
+\subsection{Tidying non-top-level binders}
%* *
%************************************************************************
\begin{code}
-tidyVarOcc (_, var_env) v = case lookupVarEnv var_env v of
- Just v' -> v'
- Nothing -> v
+tidyNameOcc :: TidyEnv -> Name -> Name
+-- In rules and instances, we have Names, and we must tidy them too
+-- 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
+
+tidyVarOcc :: TidyEnv -> Var -> Var
+tidyVarOcc (_, var_env) v = lookupVarEnv var_env v `orElse` v
-- tidyBndr is used for lambda and case binders
tidyBndr :: TidyEnv -> Var -> (TidyEnv, Var)
where
((tidy_env,var_env), new_id) = tidyIdBndr env id
- -- We need to keep around any interesting strictness and demand info
- -- because later on we may need to use it when converting to A-normal form.
+ -- We need to keep around any interesting strictness and
+ -- demand info because later on we may need to use it when
+ -- converting to A-normal form.
-- eg.
-- f (g x), where f is strict in its argument, will be converted
-- into case (g x) of z -> f z by CorePrep, but only if f still
-- CorePrep to turn the let into a case.
--
-- Similarly arity info for eta expansion in CorePrep
+ --
final_id = new_id `setIdInfo` new_info
idinfo = idInfo id
- new_info = vanillaIdInfo
+ new_info = vanillaIdInfo
`setArityInfo` exprArity rhs
- `setNewStrictnessInfo` newStrictnessInfo idinfo
+ `setAllStrictnessInfo` newStrictnessInfo idinfo
`setNewDemandInfo` newDemandInfo idinfo
-- Override the env we get back from tidyId with the new IdInfo
-- so it gets propagated to the usage sites.
new_var_env = extendVarEnv var_env id final_id
+-- Non-top-level variables
tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
tidyIdBndr env@(tidy_env, var_env) id
- = -- Non-top-level variables
+ = -- 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
-- Give the Id a fresh print-name, *and* rename its type
-- The SrcLoc isn't important now,
-- though we could extract it from the Id
--
- -- All nested Ids now have the same IdInfo, namely none,
+ -- All nested Ids now have the same IdInfo, namely vanillaIdInfo,
-- which should save some space.
- (tidy_env', occ') = tidyOccName tidy_env (getOccName id)
+ -- 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'
in
((tidy_env', var_env'), id')
+ }
\end{code}
\begin{code}
projects / ghc-hetmet.git / blobdiff