\begin{code}
module CoreTidy (
- tidyCorePgm, tidyExpr, tidyCoreExpr,
+ tidyCorePgm, tidyExpr, tidyCoreExpr, tidyIdRules,
tidyBndr, tidyBndrs
) where
import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
import CoreSyn
import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
-import CoreFVs ( ruleSomeFreeVars, exprSomeFreeVars )
-import PprCore ( pprIdCoreRule )
+import CoreFVs ( ruleLhsFreeIds, ruleRhsFreeVars, exprSomeFreeVars )
+import PprCore ( pprIdRules )
import CoreLint ( showPass, endPass )
+import CoreUtils ( exprArity )
import VarEnv
import VarSet
import Var ( Id, Var )
-import Id ( idType, idInfo, idName, isExportedId,
- idSpecialisation, idUnique, isDataConWrapId,
- mkVanillaGlobal, mkGlobalId, isLocalId,
- isDataConId, mkUserLocal, isGlobalId, globalIdDetails,
- idNewDemandInfo, setIdNewDemandInfo,
- idNewStrictness, setIdNewStrictness
+import Id ( idType, idInfo, idName, idCoreRules,
+ isExportedId, idUnique, mkVanillaGlobal, isLocalId,
+ isImplicitId, mkUserLocal, setIdInfo
)
import IdInfo {- loads of stuff -}
-import NewDemand ( isBottomingSig, topSig, isStrictDmd, isTopSig )
+import NewDemand ( isBottomingSig, topSig )
import BasicTypes ( isNeverActive )
-import Name ( getOccName, nameOccName, globaliseName, setNameOcc,
- localiseName, isGlobalName, setNameUnique
+import Name ( getOccName, nameOccName, mkInternalName, mkExternalName,
+ localiseName, isExternalName, nameSrcLoc
)
import NameEnv ( filterNameEnv )
import OccName ( TidyOccEnv, initTidyOccEnv, tidyOccName )
import HscTypes ( PersistentCompilerState( pcs_PRS ),
PersistentRenamerState( prsOrig ),
NameSupply( nsNames, nsUniqs ),
- TypeEnv, extendTypeEnvList,
+ TypeEnv, extendTypeEnvList, typeEnvIds,
ModDetails(..), TyThing(..)
)
import FiniteMap ( lookupFM, addToFM )
import UniqSupply ( splitUniqSupply, uniqFromSupply )
import List ( partition )
import Util ( mapAccumL )
-import Maybe ( isJust, fromJust, isNothing )
+import Maybe ( isJust )
import Outputable
\end{code}
; let ext_ids = findExternalSet binds_in orphans_in
; let ext_rules = findExternalRules binds_in orphans_in ext_ids
+ -- findExternalRules filters ext_rules to avoid binders that
+ -- aren't externally visible; but the externally-visible binders
+ -- are computed (by findExternalSet) assuming that all orphan
+ -- rules are exported. So in fact we may export more than we
+ -- need. (It's a sort of mutual recursion.)
-- We also make sure to avoid any exported binders. Consider
-- f{-u1-} = 1 -- Local decl
orig_ns = prsOrig prs
init_tidy_env = (orig_ns, initTidyOccEnv avoids, emptyVarEnv)
- avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in,
- isGlobalName (idName bndr)]
+ avoids = [getOccName name | bndr <- typeEnvIds env_tc,
+ let name = idName bndr,
+ isExternalName 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 tidy_rules = tidyIdCoreRules (occ_env,subst_env) ext_rules
; let prs' = prs { prsOrig = orig_ns' }
pcs' = pcs { pcs_PRS = prs' }
- ; let final_ids = [ id | bind <- tidy_binds
+ ; let final_ids = [ id
+ | bind <- tidy_binds
, id <- bindersOf bind
- , isGlobalName (idName id)]
+ , isExternalName (idName id)]
-- Dfuns are local Ids that might have
-- changed their unique during tidying
; 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))
+ (pprIdRules tidy_rules)
; return (pcs', tidy_details)
}
-- in interface files, because they are needed by importing modules when
-- using the compilation manager
- -- We keep constructor workers,
- -- because they won't appear in the bindings from which final_ids are derived!
- keep_it (AnId id) = isDataConId id -- Remove all Ids except constructor workers
+ -- 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}
findExternalRules binds orphan_rules ext_ids
| opt_OmitInterfacePragmas = []
| otherwise
- = orphan_rules ++ local_rules
+ = filter needed_rule (orphan_rules ++ local_rules)
where
- local_rules = [ (id, rule)
+ local_rules = [ 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
- ]
+ rule <- idCoreRules id
+ ]
+ needed_rule (id, rule)
+ = 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
+
+ && not (any internal_id (varSetElems (ruleLhsFreeIds rule)))
+ -- Don't export a rule whose LHS mentions an Id that
+ -- is completely internal (i.e. not visible to an
+ -- importing module)
+
+ internal_id id = isLocalId id && not (id `elemVarEnv` ext_ids)
\end{code}
%************************************************************************
= foldr find init_needed binds
where
orphan_rule_ids :: IdSet
- orphan_rule_ids = unionVarSets [ ruleSomeFreeVars isLocalId rule
+ orphan_rule_ids = unionVarSets [ ruleRhsFreeVars rule
| (_, rule) <- orphan_rules]
init_needed :: IdEnv Bool
init_needed = mapUFM (\_ -> False) orphan_rule_ids
= ((orig,occ,subst) , NonRec bndr' rhs')
where
((orig,occ,subst), bndr')
- = tidyTopBinder mod ext_ids cg_info_env rec_tidy_env rhs' top_tidy_env 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
= ((orig,occ,subst), (bndr',rhs'))
where
((orig,occ,subst), bndr')
- = tidyTopBinder mod ext_ids cg_info_env
- rec_tidy_env rhs' top_tidy_env 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 -> CoreExpr
- -- The TidyEnv is used to tidy the IdInfo
- -- The expr is the already-tided RHS
- -- Both are knot-tied: don't look at them!
+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 tidy_env rhs
+tidyTopBinder mod ext_ids cg_info_env rec_tidy_env rhs tidy_rhs
env@(ns2, occ_env2, subst_env2) id
-
- | isDataConWrapId id -- Don't tidy constructor wrappers
- = (env, id) -- The Id is stored in the TyCon, so it would be bad
- -- if anything changed
-
--- HACK ALERT: we *do* tidy record selectors. Reason: they mention error
--- messages, which may be floated out:
--- x_field pt = case pt of
--- Rect x y -> y
--- Pol _ _ -> error "buggle wuggle"
--- The error message will be floated out so we'll get
--- lvl5 = error "buggle wuggle"
--- x_field pt = case pt of
--- Rect x y -> y
--- Pol _ _ -> lvl5
---
--- When this happens, it's vital that the Id exposed to importing modules
--- (by ghci) mentions lvl5 in its unfolding, not the un-tidied version.
---
--- What about the Id in the TyCon? It probably shouldn't be in the TyCon at
--- all, but in any case it will have the error message inline so it won't matter.
-
-
- | otherwise
-- This function is the heart of Step 2
- -- The second env is the one to use for the IdInfo
+ -- 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
(orig_env', occ_env', name') = tidyTopName mod ns2 occ_env2
is_external
(idName id)
- ty' = tidyTopType (idType id)
- cg_info = lookupCgInfo cg_info_env name'
- idinfo' = tidyIdInfo tidy_env is_external unfold_info cg_info id
+ ty' = tidyTopType (idType id)
+ idinfo = tidyTopIdInfo rec_tidy_env is_external
+ (idInfo id) unfold_info arity
+ (lookupCgInfo cg_info_env name')
- id' | isGlobalId id = mkGlobalId (globalIdDetails id) name' ty' idinfo'
- | otherwise = mkVanillaGlobal name' ty' idinfo'
- -- The test ensures that record selectors (which must be tidied; see above)
- -- retain their details. If it's forgotten, importing modules get confused.
+ id' = mkVanillaGlobal name' ty' idinfo
subst_env' = extendVarEnv subst_env2 id 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 rhs
+ 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
-tidyIdInfo tidy_env is_external unfold_info cg_info id
+
+
+-- 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
- -- No IdInfo if the Id isn't external, or if we don't have -O
- = vanillaIdInfo
- `setCgInfo` cg_info
- `setNewStrictnessInfo` newStrictnessInfo core_idinfo
- -- Keep strictness; it's used by CorePrep
+ -- Only basic info if the Id isn't external, or if we don't have -O
+ = basic_info
- | otherwise
- = vanillaIdInfo
- `setCgInfo` cg_info
- `setNewStrictnessInfo` newStrictnessInfo core_idinfo
- `setInlinePragInfo` inlinePragInfo core_idinfo
+ | otherwise -- Add extra optimisation info
+ = basic_info
+ `setInlinePragInfo` inlinePragInfo idinfo
`setUnfoldingInfo` unfold_info
- `setWorkerInfo` tidyWorker tidy_env (workerInfo core_idinfo)
- -- NB: we throw away the Rules
- -- They have already been extracted by findExternalRules
+ `setWorkerInfo` tidyWorker tidy_env (workerInfo idinfo)
+ -- NB: we throw away the Rules
+ -- They have already been extracted by findExternalRules
+
where
- core_idinfo = idInfo id
-
+ -- baasic_info is attached to every top-level binder
+ basic_info = vanillaIdInfo
+ `setCgInfo` cg_info
+ `setArityInfo` arity
+ `setAllStrictnessInfo` 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.
+-- we intend to externalise it.
tidyTopName mod ns occ_env external name
| global && internal = (ns, occ_env, localiseName name)
-- so they already have the "right" unique
-- And it's a system-wide unique too
- | local && internal = (ns { nsUniqs = us2 }, occ_env', unique_name)
+ | 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
+ -- if we do -split-objs we externalise 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 { nsUniqs = us2, nsNames = ns_names' }, occ_env', global_name)
- -- If we want to globalise a currently-local name, check
+ Just orig -> (ns, occ_env', orig)
+ Nothing -> (ns_w_global, occ_env', new_external_name)
+ -- If we want to externalise a currently-local name, check
-- whether we have already assigned a unique for it.
- -- If so, use it; if not, extend the table
+ -- 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
+ global = isExternalName name
local = not global
internal = not external
ns_names = nsNames ns
ns_uniqs = nsUniqs ns
(us1, us2) = splitUniqSupply ns_uniqs
- unique_name = setNameUnique (setNameOcc name occ') (uniqFromSupply us1)
- global_name = globaliseName unique_name mod
- ns_names' = addToFM ns_names key global_name
+ uniq = uniqFromSupply us1
+ loc = nameSrcLoc name
+
+ new_local_name = mkInternalName uniq occ' loc
+ new_external_name = mkExternalName uniq mod occ' loc
+
+ ns_w_local = ns { nsUniqs = us2 }
+ ns_w_global = ns { nsUniqs = us2, nsNames = addToFM ns_names key new_external_name }
------------ Worker --------------
= NoWorker
------------ Rules --------------
-tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule]
-tidyIdRules env [] = []
-tidyIdRules env ((fn,rule) : rules)
+tidyIdRules :: Id -> [IdCoreRule]
+tidyIdRules id = tidyIdCoreRules emptyTidyEnv (idCoreRules id)
+
+tidyIdCoreRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule]
+tidyIdCoreRules env [] = []
+tidyIdCoreRules env ((fn,rule) : rules)
= tidyRule env rule =: \ rule ->
- tidyIdRules env rules =: \ rules ->
+ tidyIdCoreRules env rules =: \ rules ->
((tidyVarOcc env fn, rule) : rules)
tidyRule :: TidyEnv -> CoreRule -> CoreRule
--
-- Similarly for the demand info - on a let binder, this tells
-- CorePrep to turn the let into a case.
- final_id
- | totally_boring_info = new_id
- | otherwise = new_id `setIdNewDemandInfo` dmd_info
- `setIdNewStrictness` new_strictness
-
- -- override the env we get back from tidyId with the new IdInfo
+ --
+ -- Similarly arity info for eta expansion in CorePrep
+ final_id = new_id `setIdInfo` new_info
+ idinfo = idInfo id
+ new_info = vanillaIdInfo
+ `setArityInfo` exprArity rhs
+ `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
- dmd_info = idNewDemandInfo id
- new_strictness = idNewStrictness id
- totally_boring_info = isTopSig new_strictness && not (isStrictDmd dmd_info)
-
+-- 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 local Ids now have the same IdInfo, which should save some
- -- space.
- (tidy_env', occ') = tidyOccName tidy_env (getOccName id)
+ -- All nested Ids now have the same IdInfo, namely none,
+ -- which should save some space.
ty' = tidyType env (idType id)
id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc
var_env' = extendVarEnv var_env id id'
in
((tidy_env', var_env'), id')
+ }
\end{code}
\begin{code}
projects / ghc-hetmet.git / blobdiff