\begin{code}
module CoreTidy (
- tidyCorePgm, tidyExpr,
+ tidyCorePgm, tidyExpr, tidyCoreExpr, tidyIdRules,
tidyBndr, tidyBndrs
) where
#include "HsVersions.h"
-import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas, dopt )
+import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
import CoreSyn
import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
-import CoreFVs ( ruleSomeFreeVars, exprSomeFreeVars )
+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,
- mkVanillaId, mkId, isLocalId, omitIfaceSigForId,
- setIdStrictness, setIdDemandInfo,
+import Id ( idType, idInfo, idName, idCoreRules,
+ isExportedId, idUnique, mkVanillaGlobal, isLocalId,
+ isImplicitId, mkUserLocal, setIdInfo
)
-import IdInfo ( mkIdInfo,
- IdFlavour(..), flavourInfo, ppFlavourInfo,
- specInfo, setSpecInfo,
- cprInfo, setCprInfo,
- inlinePragInfo, setInlinePragInfo, isNeverInlinePrag,
- strictnessInfo, setStrictnessInfo, isBottomingStrictness,
- unfoldingInfo, setUnfoldingInfo,
- demandInfo,
- occInfo, isLoopBreaker,
- workerInfo, setWorkerInfo, WorkerInfo(..)
- )
-import Name ( getOccName, nameOccName, globaliseName, setNameOcc,
- localiseName, mkLocalName, isGlobalName
+import IdInfo {- loads of stuff -}
+import NewDemand ( isBottomingSig, topSig )
+import BasicTypes ( isNeverActive )
+import Name ( getOccName, nameOccName, mkInternalName, mkExternalName,
+ localiseName, isExternalName, nameSrcLoc
)
+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 ),
- OrigNameEnv( origNames ), OrigNameNameEnv
+import HscTypes ( PersistentCompilerState( pcs_PRS ),
+ PersistentRenamerState( prsOrig ),
+ NameSupply( nsNames, nsUniqs ),
+ TypeEnv, extendTypeEnvList, typeEnvIds,
+ ModDetails(..), TyThing(..)
)
-import Unique ( Uniquable(..) )
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 Outputable
+import UniqSupply ( splitUniqSupply, uniqFromSupply )
import List ( partition )
import Util ( mapAccumL )
+import Maybe ( isJust )
+import Outputable
\end{code}
IdEnv Bool
-
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 final IdInfo; in ptic,
- * Its flavour becomes ConstantId, reflecting the fact that
- from now on we regard it as a constant, not local, Id
+ 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
\begin{code}
tidyCorePgm :: DynFlags -> Module
-> PersistentCompilerState
- -> [CoreBind] -> [IdCoreRule]
- -> IO (PersistentCompilerState, [CoreBind], [IdCoreRule])
-tidyCorePgm dflags mod pcs binds_in orphans_in
+ -> 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 ((orig_env', occ_env, subst_env), binds_out)
- = mapAccumL (tidyTopBind mod ext_ids) init_tidy_env binds_in
-
- ; let orphans_out = tidyIdRules (occ_env,subst_env) orphans_in
+ ; 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.)
- ; let pcs' = pcs { pcs_PRS = prs { prsOrig = orig { origNames = orig_env' }}}
-
- ; endPass dflags "Tidy Core" (dopt Opt_D_dump_simpl dflags ||
- dopt Opt_D_verbose_core2core dflags)
- binds_out
-
- ; return (pcs', binds_out, orphans_out)
- }
- where
-- We also make sure to avoid any exported binders. Consider
-- f{-u1-} = 1 -- Local 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 = origNames orig
+ ; 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,
+ 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 = 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
+ , id <- bindersOf bind
+ , isExternalName (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"
+ (pprIdRules tidy_rules)
+
+ ; return (pcs', tidy_details)
+ }
+
+tidyCoreExpr :: CoreExpr -> IO CoreExpr
+tidyCoreExpr expr = return (tidyExpr emptyTidyEnv expr)
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Write a new interface file}
+%* *
+%************************************************************************
- init_tidy_env = (orig_env, initTidyOccEnv avoids, emptyVarEnv)
- avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in,
- isGlobalName (idName bndr)]
+\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
+ = filter needed_rule (orphan_rules ++ local_rules)
+ where
+ local_rules = [ rule
+ | id <- bindersOfBinds binds,
+ id `elemVarEnv` ext_ids,
+ 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}
%************************************************************************
%* *
\begin{code}
findExternalSet :: [CoreBind] -> [IdCoreRule]
- -> IdEnv Bool -- True <=> show unfolding
+ -> 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 isIdAndLocal rule
+ orphan_rule_ids = unionVarSets [ ruleRhsFreeVars rule
| (_, rule) <- orphan_rules]
init_needed :: IdEnv Bool
init_needed = mapUFM (\_ -> False) orphan_rule_ids
need_id needed_set id = id `elemVarEnv` needed_set || isExportedId id
need_pr needed_set (id,rhs) = need_id needed_set id
-isIdAndLocal id = isId id && isLocalId id
-
addExternal :: (Id,CoreExpr) -> IdEnv Bool -> IdEnv Bool
-- The Id is needed; extend the needed set
-- with it and its dependents (free vars etc)
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
rhs_is_small && -- Small enough
okToUnfoldInHiFile rhs -- No casms etc
- unfold_ids | show_unfold = exprSomeFreeVars isIdAndLocal rhs
+ unfold_ids | show_unfold = exprSomeFreeVars isLocalId rhs
| otherwise = emptyVarSet
worker_ids = case worker_info of
\begin{code}
-type TopTidyEnv = (OrigNameNameEnv, 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)
-- 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'
-
+--
+-- * 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 exernal
+ -> IdEnv Bool -- Domain = Ids that should be external
-- True <=> their unfolding is external too
+ -> CgInfoEnv
-> TopTidyEnv -> CoreBind
-> (TopTidyEnv, CoreBind)
-tidyTopBind mod ext_ids env (NonRec bndr rhs)
- = (env', NonRec bndr' rhs')
+tidyTopBind mod ext_ids cg_info_env top_tidy_env (NonRec bndr rhs)
+ = ((orig,occ,subst) , NonRec bndr' rhs')
where
- rhs' = tidyTopRhs env rhs
- (env', bndr') = tidyTopBinder mod ext_ids env rhs' env bndr
+ ((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 env (Rec prs)
+tidyTopBind mod ext_ids cg_info_env top_tidy_env (Rec prs)
= (final_env, Rec prs')
where
- (final_env, prs') = mapAccumL do_one env prs
- do_one env (bndr,rhs) = (env', (bndr', rhs'))
- where
- rhs' = tidyTopRhs final_env rhs
- (env', bndr') = tidyTopBinder mod ext_ids final_env
- rhs' env bndr
-
-tidyTopRhs :: TopTidyEnv -> CoreExpr -> CoreExpr
- -- Just an impedence matcher
-tidyTopRhs (_, occ_env, subst_env) rhs = tidyExpr (occ_env, subst_env) rhs
-
-tidyTopBinder :: Module -> IdEnv Bool
- -> TopTidyEnv -> CoreExpr
+ (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)
-tidyTopBinder mod ext_ids env_idinfo rhs env@(orig_env, occ_env, subst_env) id
- | omitIfaceSigForId id -- Don't mess with constructors,
- = (env, id) -- record selectors, and the like
+ -- NB: tidyTopBinder doesn't affect the unique supply
- | otherwise
+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 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', subst_env'), id')
where
- (orig_env', occ_env', name') = tidyTopName mod orig_env occ_env
+ (orig_env', occ_env', name') = tidyTopName mod ns2 occ_env2
is_external
(idName id)
- ty' = tidyTopType (idType id)
- idinfo' = tidyIdInfo env_idinfo is_external unfold_info id
- id' = mkId name' ty' idinfo'
- subst_env' = extendVarEnv subst_env id 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 = maybeToBool maybe_external
+ 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
-tidyIdInfo (_, occ_env, subst_env) is_external unfold_info id
+ -- 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
- -- No IdInfo if the Id isn't external, or if we don't have -O
- = mkIdInfo new_flavour
- `setStrictnessInfo` strictnessInfo core_idinfo
- -- Keep strictness info; it's used by the code generator
-
- | otherwise
- = mkIdInfo new_flavour
- `setCprInfo` cprInfo core_idinfo
- `setStrictnessInfo` strictnessInfo core_idinfo
- `setInlinePragInfo` inlinePragInfo core_idinfo
- `setUnfoldingInfo` unfold_info
- `setWorkerInfo` tidyWorker tidy_env (workerInfo core_idinfo)
- `setSpecInfo` tidyRules tidy_env (specInfo core_idinfo)
- where
- tidy_env = (occ_env, subst_env)
- core_idinfo = idInfo id
-
- -- A DFunId must stay a DFunId, so that we can gather the
- -- DFunIds up later. Other local things become ConstantIds.
- new_flavour = case flavourInfo core_idinfo of
- VanillaId -> ConstantId
- ExportedId -> ConstantId
- ConstantId -> ConstantId -- e.g. Default methods
- DictFunId -> DictFunId
- flavour -> pprTrace "tidyIdInfo" (ppr id <+> ppFlavourInfo flavour)
- flavour
-
-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')
- | global && external = (orig_env, occ_env, name)
- | local && external = globalise
+ -- 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
- -- If we want to globalise a currently-local name, check
+ -- 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 externalise 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 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_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
- globalise = case lookupFM orig_env key of
- Just orig -> (orig_env, occ_env', orig)
- Nothing -> (addToFM orig_env key global_name, occ_env', global_name)
+ -- 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.
- (occ_env', occ') = tidyOccName occ_env (nameOccName name)
- key = (moduleName mod, occ')
- global_name = globaliseName (setNameOcc name occ') mod
- global = isGlobalName name
+ where
+ global = isExternalName name
local = not global
internal = not external
-tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule]
-tidyIdRules env rules
- = [ (tidyVarOcc env fn, tidyRule env rule) | (fn,rule) <- rules ]
+ (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 = 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 --------------
tidyWorker tidy_env (HasWorker work_id wrap_arity)
= HasWorker (tidyVarOcc tidy_env work_id) wrap_arity
-tidyWorker tidy_env NoWorker
+tidyWorker tidy_env other
= NoWorker
-tidyRules :: TidyEnv -> CoreRules -> CoreRules
-tidyRules env (Rules rules fvs)
- = Rules (map (tidyRule env) rules)
- (foldVarSet tidy_set_elem emptyVarSet fvs)
- where
- tidy_set_elem var new_set = extendVarSet new_set (tidyVarOcc env var)
+------------ 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 ->
+ tidyIdCoreRules env rules =: \ rules ->
+ ((tidyVarOcc env fn, rule) : rules)
tidyRule :: TidyEnv -> CoreRule -> CoreRule
-tidyRule env rule@(BuiltinRule _) = rule
-tidyRule env (Rule name vars tpl_args rhs)
- = (Rule name vars' (map (tidyExpr env') tpl_args) (tidyExpr env' rhs))
- where
- (env', vars') = tidyBndrs env vars
+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}
-
%************************************************************************
%* *
\subsection{Step 2: inner tidying
\begin{code}
tidyBind :: TidyEnv
-> CoreBind
- -> (TidyEnv, CoreBind)
+ -> (TidyEnv, CoreBind)
+
tidyBind env (NonRec bndr rhs)
- = let
- (env', bndr') = tidyBndr env bndr
- rhs' = tidyExpr env' rhs
- -- We use env' when tidying the RHS even though it's not
- -- strictly necessary; it makes the tidied code pretty
- -- hard to read if we don't!
- in
- (env', NonRec bndr' rhs')
+ = tidyLetBndr env (bndr,rhs) =: \ (env', bndr') ->
+ (env', NonRec bndr' (tidyExpr env' rhs))
tidyBind env (Rec prs)
- = (final_env, Rec prs')
- where
- (final_env, prs') = mapAccumL do_one env prs
- do_one env (bndr,rhs) = (env', (bndr', rhs'))
- where
- (env', bndr') = tidyBndr env bndr
- rhs' = tidyExpr final_env rhs
+ = mapAccumL tidyLetBndr env prs =: \ (env', bndrs') ->
+ map (tidyExpr env') (map snd prs) =: \ rhss' ->
+ (env', Rec (zip bndrs' rhss'))
-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 (Let b e) = Let b' (tidyExpr env' e)
- where
- (env', b') = tidyBind env b
+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 (Case e b alts) = Case (tidyExpr env e) b' (map (tidyAlt env') alts)
- where
- (env', b') = tidyBndr env b
+tidyExpr env (Let b e)
+ = tidyBind env b =: \ (env', b') ->
+ Let b' (tidyExpr env' e)
-tidyExpr env (Var v) = Var (tidyVarOcc env v)
+tidyExpr env (Case e b alts)
+ = tidyBndr env b =: \ (env', b) ->
+ Case (tidyExpr env e) b (map (tidyAlt env') alts)
-tidyExpr env (Lam b e) = Lam b' (tidyExpr env' e)
- where
- (env', b') = tidyBndr env b
+tidyExpr env (Lam b e)
+ = tidyBndr env b =: \ (env', b) ->
+ Lam b (tidyExpr env' e)
-tidyAlt env (con, vs, rhs) = (con, vs', tidyExpr env' rhs)
- where
- (env', vs') = tidyBndrs env vs
-tidyNote env (Coerce t1 t2) = Coerce (tidyType env t1) (tidyType env t2)
+tidyAlt env (con, vs, rhs)
+ = tidyBndrs env vs =: \ (env', vs) ->
+ (con, vs, tidyExpr env' rhs)
+tidyNote env (Coerce t1 t2) = Coerce (tidyType env t1) (tidyType env t2)
tidyNote env note = note
\end{code}
Just v' -> v'
Nothing -> v
+-- 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
+tidyBndr env var
+ | isTyVar var = tidyTyVarBndr env var
+ | otherwise = tidyIdBndr env var
tidyBndrs :: TidyEnv -> [Var] -> (TidyEnv, [Var])
tidyBndrs env vars = mapAccumL tidyBndr env vars
-tidyId :: TidyEnv -> Id -> (TidyEnv, Id)
-tidyId env@(tidy_env, var_env) id
- = -- Non-top-level variables
+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.
+ --
+ -- 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
+
+-- 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
+ -- 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
- name' = mkLocalName (getUnique id) occ' noSrcLoc
- (tidy_env', occ') = tidyOccName tidy_env (getOccName id)
+ -- The SrcLoc isn't important now,
+ -- though we could extract it from the Id
+ --
+ -- All nested Ids now have the same IdInfo, namely none,
+ -- which should save some space.
ty' = tidyType env (idType id)
- idinfo = idInfo id
- id' = mkVanillaId name' ty'
- `setIdStrictness` strictnessInfo idinfo
- `setIdDemandInfo` demandInfo idinfo
- -- NB: This throws away the IdInfo of the Id, which we
- -- no longer need. That means we don't need to
- -- run over it with env, nor renumber it.
- --
- -- The exception is strictness and demand info, which
- -- is used to decide whether to use let or case for
- -- function arguments and let bindings
-
+ id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc
var_env' = extendVarEnv var_env id id'
in
- ((tidy_env', var_env'), id')
+ ((tidy_env', var_env'), id')
+ }
+\end{code}
+
+\begin{code}
+m =: k = m `seq` k m
\end{code}
projects / ghc-hetmet.git / blobdiff