import CoreSyn
import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
import CoreFVs ( ruleSomeFreeVars, exprSomeFreeVars )
+import PprCore ( pprIdCoreRule )
import CoreLint ( showPass, endPass )
import VarEnv
import VarSet
import Var ( Id, Var )
import Id ( idType, idInfo, idName, isExportedId,
- idSpecialisation, idUnique,
- mkVanillaGlobal, isLocalId, isImplicitId,
- hasNoBinding, mkUserLocal
+ idSpecialisation, idUnique, isDataConWrapId,
+ mkVanillaGlobal, mkGlobalId, isLocalId,
+ isDataConId, mkUserLocal, isGlobalId, globalIdDetails,
+ idNewDemandInfo, setIdNewDemandInfo,
+ idNewStrictness, setIdNewStrictness
)
import IdInfo {- loads of stuff -}
+import NewDemand ( isBottomingSig, topSig, isStrictDmd, isTopSig )
+import BasicTypes ( isNeverActive )
import Name ( getOccName, nameOccName, globaliseName, setNameOcc,
- localiseName, isGlobalName
+ localiseName, isGlobalName, setNameUnique
)
import NameEnv ( filterNameEnv )
import OccName ( TidyOccEnv, initTidyOccEnv, tidyOccName )
-import Type ( tidyTopType, tidyType, tidyTyVar )
+import Type ( tidyTopType, tidyType, tidyTyVarBndr )
import Module ( Module, moduleName )
import HscTypes ( PersistentCompilerState( pcs_PRS ),
PersistentRenamerState( prsOrig ),
- NameSupply( nsNames ), OrigNameCache,
+ NameSupply( nsNames, nsUniqs ),
TypeEnv, extendTypeEnvList,
ModDetails(..), TyThing(..)
)
import FiniteMap ( lookupFM, addToFM )
-import Maybes ( maybeToBool, orElse )
-import ErrUtils ( showPass )
+import Maybes ( orElse )
+import ErrUtils ( showPass, dumpIfSet_core )
import SrcLoc ( noSrcLoc )
import UniqFM ( mapUFM )
+import UniqSupply ( splitUniqSupply, uniqFromSupply )
import List ( partition )
import Util ( mapAccumL )
+import Maybe ( isJust, fromJust, isNothing )
import Outputable
\end{code}
Step 2: Tidy the program
~~~~~~~~~~~~~~~~~~~~~~~~
-Next we traverse the bindings top to bottom. For each top-level
+Next we traverse the bindings top to bottom. For each *top-level*
binder
- - Make all external Ids have Global names and vice versa
+ 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
- - Give external ids a "tidy" occurrence name. This means
+ 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).
- - Give external Ids the same Unique as they had before
- if the name is in the renamer's name cache
-
- - Give the Id its UTTERLY FINAL IdInfo; in ptic,
+ 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
; let ext_ids = findExternalSet binds_in orphans_in
; let ext_rules = findExternalRules binds_in orphans_in ext_ids
- ; let ((orig_env', occ_env, subst_env), tidy_binds)
+ -- 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 bndr | bndr <- bindersOfBinds binds_in,
+ isGlobalName (idName bndr)]
+
+ ; 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 { nsNames = orig_env' } }
+ ; let prs' = prs { prsOrig = orig_ns' }
pcs' = pcs { pcs_PRS = prs' }
; let final_ids = [ id | bind <- tidy_binds
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)
}
- where
- -- 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.
- prs = pcs_PRS pcs
- orig = prsOrig prs
- orig_env = nsNames orig
-
- init_tidy_env = (orig_env, initTidyOccEnv avoids, emptyVarEnv)
- avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in,
- isGlobalName (idName bndr)]
tidyCoreExpr :: CoreExpr -> IO CoreExpr
tidyCoreExpr expr = return (tidyExpr emptyTidyEnv expr)
-- 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) = hasNoBinding id -- Remove all Ids except constructor workers
+ -- 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
keep_it other = True -- Keep all TyCons and Classes
\end{code}
spec_ids
idinfo = idInfo id
- dont_inline = isNeverInlinePrag (inlinePragInfo idinfo)
+ dont_inline = isNeverActive (inlinePragInfo idinfo)
loop_breaker = isLoopBreaker (occInfo idinfo)
- bottoming_fn = isBottomingStrictness (strictnessInfo idinfo)
+ bottoming_fn = isBottomingSig (newStrictnessInfo idinfo `orElse` topSig)
spec_ids = rulesRhsFreeVars (specInfo idinfo)
worker_info = workerInfo idinfo
\begin{code}
-type TopTidyEnv = (OrigNameCache, TidyOccEnv, VarEnv Var)
+type TopTidyEnv = (NameSupply, TidyOccEnv, VarEnv Var)
-- TopTidyEnv: when tidying we need to know
--- * orig_env: Any pre-ordained Names. These may have arisen because the
+-- * 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)
-- NB: tidyTopBinder doesn't affect the unique supply
tidyTopBinder mod ext_ids cg_info_env tidy_env rhs
- env@(orig_env2, occ_env2, subst_env2) id
+ 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.
- | isImplicitId id -- Don't mess with constructors,
- = (env, id) -- record selectors, and the like
| otherwise
-- This function is the heart of Step 2
= ((orig_env', occ_env', subst_env'), id')
where
- (orig_env', occ_env', name') = tidyTopName mod orig_env2 occ_env2
+ (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
- id' = mkVanillaGlobal name' ty' idinfo'
+ 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.
+
subst_env' = extendVarEnv subst_env2 id id'
maybe_external = lookupVarEnv ext_ids id
- is_external = maybeToBool maybe_external
+ is_external = isJust maybe_external
-- Expose an unfolding if ext_ids tells us to
show_unfold = maybe_external `orElse` False
| opt_OmitInterfacePragmas || not is_external
-- No IdInfo if the Id isn't external, or if we don't have -O
= vanillaIdInfo
- `setCgInfo` cg_info
- `setStrictnessInfo` strictnessInfo core_idinfo
+ `setCgInfo` cg_info
+ `setNewStrictnessInfo` newStrictnessInfo core_idinfo
-- Keep strictness; it's used by CorePrep
| otherwise
= vanillaIdInfo
- `setCgInfo` cg_info
- `setCprInfo` cprInfo core_idinfo
- `setStrictnessInfo` strictnessInfo core_idinfo
- `setInlinePragInfo` inlinePragInfo core_idinfo
- `setUnfoldingInfo` unfold_info
- `setWorkerInfo` tidyWorker tidy_env (workerInfo core_idinfo)
+ `setCgInfo` cg_info
+ `setNewStrictnessInfo` newStrictnessInfo core_idinfo
+ `setInlinePragInfo` inlinePragInfo core_idinfo
+ `setUnfoldingInfo` unfold_info
+ `setWorkerInfo` tidyWorker tidy_env (workerInfo core_idinfo)
-- NB: we throw away the Rules
-- They have already been extracted by findExternalRules
where
-- 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 orig_env occ_env external name
- | global && internal = (orig_env, occ_env, localiseName name)
-
- | local && internal = (orig_env, occ_env', setNameOcc name occ')
- -- Even local, internal names must get a unique occurrence, because
- -- if we do -split-objs we globalise the name later, n the code generator
+tidyTopName mod ns occ_env external name
+ | global && internal = (ns, occ_env, localiseName name)
- | global && external = (orig_env, occ_env, 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 { nsUniqs = us2 }, occ_env', unique_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 orig_env key of
- Just orig -> (orig_env, occ_env', orig)
- Nothing -> (addToFM orig_env key global_name, occ_env', global_name)
+ | 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
-- whether we have already assigned a unique for it.
-- If so, use it; if not, extend the table
where
- (occ_env', occ') = tidyOccName occ_env (nameOccName name)
- key = (moduleName mod, occ')
- global_name = globaliseName (setNameOcc name occ') mod
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
+ unique_name = setNameUnique (setNameOcc name occ') (uniqFromSupply us1)
+ global_name = globaliseName unique_name mod
+ ns_names' = addToFM ns_names key global_name
+
+
------------ Worker --------------
tidyWorker tidy_env (HasWorker work_id wrap_arity)
= HasWorker (tidyVarOcc tidy_env work_id) wrap_arity
((tidyVarOcc env fn, rule) : rules)
tidyRule :: TidyEnv -> CoreRule -> CoreRule
-tidyRule env rule@(BuiltinRule _) = rule
-tidyRule env (Rule name vars tpl_args rhs)
+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 vars tpl_args (tidyExpr env' rhs))
+ (Rule name act vars tpl_args (tidyExpr env' rhs))
\end{code}
%************************************************************************
-> (TidyEnv, CoreBind)
tidyBind env (NonRec bndr rhs)
- = tidyBndrWithRhs env (bndr,rhs) =: \ (env', bndr') ->
+ = tidyLetBndr env (bndr,rhs) =: \ (env', bndr') ->
(env', NonRec bndr' (tidyExpr env' rhs))
tidyBind env (Rec prs)
- = mapAccumL tidyBndrWithRhs env prs =: \ (env', bndrs') ->
+ = mapAccumL tidyLetBndr env prs =: \ (env', bndrs') ->
map (tidyExpr env') (map snd prs) =: \ rhss' ->
(env', Rec (zip bndrs' rhss'))
-- tidyBndr is used for lambda and case binders
tidyBndr :: TidyEnv -> Var -> (TidyEnv, Var)
tidyBndr env var
- | isTyVar var = tidyTyVar env var
- | otherwise = tidyId env var
+ | isTyVar var = tidyTyVarBndr env var
+ | otherwise = tidyIdBndr env var
tidyBndrs :: TidyEnv -> [Var] -> (TidyEnv, [Var])
tidyBndrs env vars = mapAccumL tidyBndr env vars
--- tidyBndrWithRhs is used for let binders
-tidyBndrWithRhs :: TidyEnv -> (Id, CoreExpr) -> (TidyEnv, Var)
-tidyBndrWithRhs env (id,rhs) = tidyId env id
-
-tidyId :: TidyEnv -> Id -> (TidyEnv, Id)
-tidyId env@(tidy_env, var_env) id
+tidyLetBndr :: TidyEnv -> (Id, CoreExpr) -> (TidyEnv, Var)
+-- Used for local (non-top-level) let(rec)s
+tidyLetBndr env (id,rhs)
+ = ((tidy_env,new_var_env), final_id)
+ 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.
+ -- 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
+ -- has its strictness info.
+ --
+ -- 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
+ -- 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)
+
+tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
+tidyIdBndr env@(tidy_env, var_env) id
= -- Non-top-level variables
let
-- Give the Id a fresh print-name, *and* rename its type
-- All local Ids now have the same IdInfo, which should save some
-- space.
(tidy_env', occ') = tidyOccName tidy_env (getOccName id)
- ty' = tidyType (tidy_env,var_env) (idType id)
+ ty' = tidyType env (idType id)
id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc
var_env' = extendVarEnv var_env id id'
in