%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnIfaces]{Cacheing and Renaming of Interfaces}
\begin{code}
-module RnIfaces (
+module RnIfaces
+ (
getInterfaceExports,
- getImportedInstDecls,
- getSpecialInstModules, getDeferredDataDecls,
- importDecl, recordSlurp,
- getImportVersions, getSlurpedNames, getRnStats,
+ recordLocalSlurps,
+ mkImportInfo,
- checkUpToDate,
+ slurpImpDecls, closeDecls,
- getDeclBinders,
- mkSearchPath
- ) where
+ RecompileRequired, outOfDate, upToDate, recompileRequired
+ )
+where
#include "HsVersions.h"
-import CmdLineOpts ( opt_PruneTyDecls, opt_PruneInstDecls,
- opt_D_show_rn_imports, opt_IgnoreIfacePragmas
+import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls )
+import HscTypes
+import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..),
+ InstDecl(..), HsType(..), hsTyVarNames, getBangType
)
-import HsSyn ( HsDecl(..), TyDecl(..), ClassDecl(..), InstDecl(..), IfaceSig(..),
- HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
- hsDeclName
+import HsImpExp ( ImportDecl(..) )
+import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
+import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl,
+ extractHsTyNames, extractHsCtxtTyNames,
+ tyClDeclFVs, ruleDeclFVs, instDeclFVs
)
-import BasicTypes ( Version, NewOrData(..), IfaceFlavour(..) )
-import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyDecl,
- RdrName(..), rdrNameOcc
+import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface,
+ loadOrphanModules
)
-import RnEnv ( newImportedGlobalName, addImplicitOccsRn,
- ifaceFlavour, availName, availNames, addAvailToNameSet
- )
-import RnSource ( rnHsSigType )
+import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl )
+import RnEnv
import RnMonad
-import RnHsSyn ( RenamedHsDecl )
-import ParseIface ( parseIface, IfaceStuff(..) )
-
-import FiniteMap ( FiniteMap, sizeFM, emptyFM, delFromFM,
- lookupFM, addToFM, addToFM_C, addListToFM,
- fmToList
- )
-import Name ( Name {-instance NamedThing-}, Provenance, OccName(..),
- nameModule, moduleString, pprModule, isLocallyDefined,
- NameSet(..), emptyNameSet, unionNameSets, nameSetToList,
- minusNameSet, mkNameSet, elemNameSet, nameUnique, addOneToNameSet,
- isWiredInName, maybeWiredInTyConName, maybeWiredInIdName,
+import Id ( idType )
+import Type ( namesOfType )
+import TyCon ( isSynTyCon, getSynTyConDefn )
+import Name ( Name {-instance NamedThing-}, nameOccName,
+ nameModule, isLocalName, nameUnique,
NamedThing(..)
)
-import Id ( GenId, Id(..), idType, dataConTyCon, isAlgCon )
-import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn )
-import Type ( namesOfType )
-import TyVar ( GenTyVar )
-import SrcLoc ( mkSrcLoc, SrcLoc )
-import PrelMods ( pREL_GHC )
-import PrelInfo ( cCallishTyKeys )
-import Bag
-import Maybes ( MaybeErr(..), maybeToBool )
-import ListSetOps ( unionLists )
-import Outputable
-import Unique ( Unique )
-import StringBuffer ( StringBuffer, hGetStringBuffer )
-import FastString ( mkFastString )
+import Name ( elemNameEnv, delFromNameEnv )
+import Module ( Module, ModuleEnv,
+ moduleName, isHomeModule,
+ ModuleName, WhereFrom(..),
+ emptyModuleEnv,
+ extendModuleEnv_C, foldModuleEnv, lookupModuleEnv,
+ elemModuleSet, extendModuleSet
+ )
+import NameSet
+import PrelInfo ( wiredInThingEnv, fractionalClassKeys )
+import TysWiredIn ( doubleTyCon )
+import Maybes ( orElse )
+import FiniteMap
import Outputable
-
-import IO ( isDoesNotExistError )
-import List ( nub )
+import Bag
+import Util ( sortLt )
\end{code}
-
%*********************************************************
%* *
-\subsection{Statistics}
+\subsection{Getting what a module exports}
%* *
%*********************************************************
+@getInterfaceExports@ is called only for directly-imported modules.
+
\begin{code}
-getRnStats :: [RenamedHsDecl] -> RnMG SDoc
-getRnStats all_decls
- = getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod mod_map decls_fm all_names imp_names (unslurped_insts,_) deferred_data_decls inst_mods = ifaces
- n_mods = sizeFM mod_map
-
- decls_imported = filter is_imported_decl all_decls
- decls_read = [decl | (name, (_, avail, decl)) <- fmToList decls_fm,
- name == availName avail,
- -- Data, newtype, and class decls are in the decls_fm
- -- under multiple names; the tycon/class, and each
- -- constructor/class op too.
- not (isLocallyDefined name)
- ]
-
- (cd_rd, dd_rd, add_rd, nd_rd, and_rd, sd_rd, vd_rd, _) = count_decls decls_read
- (cd_sp, dd_sp, add_sp, nd_sp, and_sp, sd_sp, vd_sp, id_sp) = count_decls decls_imported
-
- inst_decls_unslurped = length (bagToList unslurped_insts)
- inst_decls_read = id_sp + inst_decls_unslurped
-
- stats = vcat
- [int n_mods <> text " interfaces read",
- hsep [int cd_sp, text "class decls imported, out of",
- int cd_rd, text "read"],
- hsep [int dd_sp, text "data decls imported (of which", int add_sp, text "abstractly), out of",
- int dd_rd, text "read"],
- hsep [int nd_sp, text "newtype decls imported (of which", int and_sp, text "abstractly), out of",
- int nd_rd, text "read"],
- hsep [int sd_sp, text "type synonym decls imported, out of",
- int sd_rd, text "read"],
- hsep [int vd_sp, text "value signatures imported, out of",
- int vd_rd, text "read"],
- hsep [int id_sp, text "instance decls imported, out of",
- int inst_decls_read, text "read"]
- ]
- in
- returnRn (hcat [text "Renamer stats: ", stats])
-
-is_imported_decl (DefD _) = False
-is_imported_decl (ValD _) = False
-is_imported_decl decl = not (isLocallyDefined (hsDeclName decl))
-
-count_decls decls
- = -- pprTrace "count_decls" (ppr decls
- --
- -- $$
- -- text "========="
- -- $$
- -- ppr imported_decls
- -- ) $
- (class_decls,
- data_decls, abstract_data_decls,
- newtype_decls, abstract_newtype_decls,
- syn_decls,
- val_decls,
- inst_decls)
+getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)])
+getInterfaceExports mod_name from
+ = loadInterface doc_str mod_name from `thenRn` \ iface ->
+ returnRn (mi_module iface, mi_exports iface)
where
- class_decls = length [() | ClD _ <- decls]
- data_decls = length [() | TyD (TyData DataType _ _ _ _ _ _ _) <- decls]
- newtype_decls = length [() | TyD (TyData NewType _ _ _ _ _ _ _) <- decls]
- abstract_data_decls = length [() | TyD (TyData DataType _ _ _ [] _ _ _) <- decls]
- abstract_newtype_decls = length [() | TyD (TyData NewType _ _ _ [] _ _ _) <- decls]
- syn_decls = length [() | TyD (TySynonym _ _ _ _) <- decls]
- val_decls = length [() | SigD _ <- decls]
- inst_decls = length [() | InstD _ <- decls]
+ doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
+\end{code}
-\end{code}
%*********************************************************
%* *
-\subsection{Loading a new interface file}
+\subsection{Keeping track of what we've slurped, and version numbers}
%* *
%*********************************************************
-\begin{code}
-loadInterface :: SDoc -> Module -> IfaceFlavour -> RnMG Ifaces
-loadInterface doc_str load_mod as_source
- = getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod mod_map decls
- all_names imp_names (insts, tycls_names)
- deferred_data_decls inst_mods = ifaces
- in
- -- CHECK WHETHER WE HAVE IT ALREADY
- case lookupFM mod_map load_mod of {
- Just (hif, _, _, _) | hif `as_good_as` as_source
- -> -- Already in the cache; don't re-read it
- returnRn ifaces ;
- other ->
-
- -- READ THE MODULE IN
- findAndReadIface doc_str load_mod as_source `thenRn` \ read_result ->
- case read_result of {
- -- Check for not found
- Nothing -> -- Not found, so add an empty export env to the Ifaces map
- -- so that we don't look again
- let
- new_mod_map = addToFM mod_map load_mod (HiFile, 0, [],[])
- new_ifaces = Ifaces this_mod new_mod_map
- decls all_names imp_names (insts, tycls_names)
- deferred_data_decls inst_mods
- in
- setIfacesRn new_ifaces `thenRn_`
- failWithRn new_ifaces (noIfaceErr load_mod) ;
-
- -- Found and parsed!
- Just (ParsedIface _ mod_vers usages exports rd_inst_mods fixs rd_decls rd_insts) ->
-
- -- LOAD IT INTO Ifaces
- -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
- --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
- -- If we do loadExport first the wrong info gets into the cache (unless we
- -- explicitly tag each export which seems a bit of a bore)
- foldlRn (loadDecl load_mod as_source) decls rd_decls `thenRn` \ new_decls ->
- mapRn loadExport exports `thenRn` \ avails_s ->
- foldlRn (loadInstDecl load_mod) insts rd_insts `thenRn` \ new_insts ->
- let
- mod_details = (as_source, mod_vers, concat avails_s, fixs)
-
- -- Exclude this module from the "special-inst" modules
- new_inst_mods = inst_mods `unionLists` (filter (/= this_mod) rd_inst_mods)
-
- new_ifaces = Ifaces this_mod
- (addToFM mod_map load_mod mod_details)
- new_decls
- all_names imp_names
- (new_insts, tycls_names)
- deferred_data_decls
- new_inst_mods
- in
- setIfacesRn new_ifaces `thenRn_`
- returnRn new_ifaces
- }}
+mkImportInof figures out what the ``usage information'' for this
+moudule is; that is, what it must record in its interface file as the
+things it uses.
-as_good_as HiFile any = True
-as_good_as any HiBootFile = True
-as_good_as _ _ = False
+We produce a line for every module B below the module, A, currently being
+compiled:
+ import B <n> ;
+to record the fact that A does import B indireclty. This is used to decide
+to look to look for B.hi rather than B.hi-boot when compiling a module that
+imports A. This line says that A imports B, but uses nothing in it.
+So we'll get an early bale-out when compiling A if B's version changes.
+\begin{code}
+mkImportInfo :: ModuleName -- Name of this module
+ -> [ImportDecl n] -- The import decls
+ -> RnMG [ImportVersion Name]
-loadExport :: ExportItem -> RnMG [AvailInfo]
-loadExport (mod, hif, entities)
- = mapRn load_entity entities
- where
- new_name occ = newImportedGlobalName mod occ hif
-
- load_entity (Avail occ)
- = new_name occ `thenRn` \ name ->
- returnRn (Avail name)
- load_entity (AvailTC occ occs)
- = new_name occ `thenRn` \ name ->
- mapRn new_name occs `thenRn` \ names ->
- returnRn (AvailTC name names)
-
-loadDecl :: Module
- -> IfaceFlavour
- -> DeclsMap
- -> (Version, RdrNameHsDecl)
- -> RnMG DeclsMap
-loadDecl mod as_source decls_map (version, decl)
- = getDeclBinders new_implicit_name decl `thenRn` \ avail ->
- returnRn (addListToFM decls_map
- [(name,(version,avail,decl')) | name <- availNames avail]
- )
- where
- {-
- If a signature decl is being loaded and we're ignoring interface pragmas,
- toss away unfolding information.
-
- Also, if the signature is loaded from a module we're importing from source,
- we do the same. This is to avoid situations when compiling a pair of mutually
- recursive modules, peering at unfolding info in the interface file of the other,
- e.g., you compile A, it looks at B's interface file and may as a result change
- it's interface file. Hence, B is recompiled, maybe changing it's interface file,
- which will the ufolding info used in A to become invalid. Simple way out is to
- just ignore unfolding info.
- -}
- decl' =
- case decl of
- SigD (IfaceSig name tp ls loc) | from_hi_boot || opt_IgnoreIfacePragmas ->
- SigD (IfaceSig name tp [] loc)
- _ -> decl
-
- new_implicit_name rdr_name loc = newImportedGlobalName mod (rdrNameOcc rdr_name) as_source
-
- from_hi_boot = case as_source of
- HiBootFile -> True
- other -> False
-
-loadInstDecl :: Module
- -> Bag IfaceInst
- -> RdrNameInstDecl
- -> RnMG (Bag IfaceInst)
-loadInstDecl mod_name insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
- =
- -- Find out what type constructors and classes are "gates" for the
- -- instance declaration. If all these "gates" are slurped in then
- -- we should slurp the instance decl too.
- --
- -- We *don't* want to count names in the context part as gates, though.
- -- For example:
- -- instance Foo a => Baz (T a) where ...
+mkImportInfo this_mod imports
+ = getIfacesRn `thenRn` \ ifaces ->
+ getHomeIfaceTableRn `thenRn` \ hit ->
+ let
+ (imp_pkg_mods, imp_home_names) = iVSlurp ifaces
+ pit = iPIT ifaces
+
+ import_all_mods :: [ModuleName]
+ -- Modules where we imported all the names
+ -- (apart from hiding some, perhaps)
+ import_all_mods = [ m | ImportDecl m _ _ _ imp_list _ <- imports,
+ import_all imp_list ]
+ where
+ import_all (Just (False, _)) = False -- Imports are specified explicitly
+ import_all other = True -- Everything is imported
+
+ -- mv_map groups together all the things imported and used
+ -- from a particular module in this package
+ -- We use a finite map because we want the domain
+ mv_map :: ModuleEnv [Name]
+ mv_map = foldNameSet add_mv emptyModuleEnv imp_home_names
+ add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [name]
+ where
+ mod = nameModule name
+ add_item names _ = name:names
+
+ -- In our usage list we record
+ -- a) Specifically: Detailed version info for imports from modules in this package
+ -- Gotten from iVSlurp plus import_all_mods
+ --
+ -- b) Everything: Just the module version for imports from modules in other packages
+ -- Gotten from iVSlurp plus import_all_mods
--
- -- Here the gates are Baz and T, but *not* Foo.
- let
- munged_inst_ty = case inst_ty of
- HsForAllTy tvs cxt ty -> HsForAllTy tvs [] ty
- HsPreForAllTy cxt ty -> HsPreForAllTy [] ty
- other -> inst_ty
+ -- c) NothingAtAll: The name only of modules, Baz, in this package that are 'below' us,
+ -- but which we didn't need at all (this is needed only to decide whether
+ -- to open Baz.hi or Baz.hi-boot higher up the tree).
+ -- This happens when a module, Foo, that we explicitly imported has
+ -- 'import Baz' in its interface file, recording that Baz is below
+ -- Foo in the module dependency hierarchy. We want to propagate this info.
+ -- These modules are in a combination of HIT/PIT and iImpModInfo
+ --
+ -- d) NothingAtAll: The name only of all orphan modules we know of (this is needed
+ -- so that anyone who imports us can find the orphan modules)
+ -- These modules are in a combination of HIT/PIT and iImpModInfo
+
+ import_info0 = foldModuleEnv mk_imp_info [] pit
+ import_info1 = foldModuleEnv mk_imp_info import_info0 hit
+ import_info = [ (mod_name, orphans, is_boot, NothingAtAll)
+ | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ] ++
+ import_info1
+
+ mk_imp_info :: ModIface -> [ImportVersion Name] -> [ImportVersion Name]
+ mk_imp_info iface so_far
+
+ | Just ns <- lookupModuleEnv mv_map mod -- Case (a)
+ = go_for_it (Specifically mod_vers maybe_export_vers
+ (mk_import_items ns) rules_vers)
+
+ | mod `elemModuleSet` imp_pkg_mods -- Case (b)
+ = go_for_it (Everything mod_vers)
+
+ | import_all_mod -- Case (a) and (b); the import-all part
+ = if is_home_pkg_mod then
+ go_for_it (Specifically mod_vers (Just export_vers) [] rules_vers)
+ else
+ go_for_it (Everything mod_vers)
+
+ | is_home_pkg_mod || has_orphans -- Case (c) or (d)
+ = go_for_it NothingAtAll
+
+ | otherwise = so_far
+ where
+ go_for_it exports = (mod_name, has_orphans, mi_boot iface, exports) : so_far
+
+ mod = mi_module iface
+ mod_name = moduleName mod
+ is_home_pkg_mod = isHomeModule mod
+ version_info = mi_version iface
+ version_env = vers_decls version_info
+ mod_vers = vers_module version_info
+ rules_vers = vers_rules version_info
+ export_vers = vers_exports version_info
+ import_all_mod = mod_name `elem` import_all_mods
+ has_orphans = mi_orphan iface
+
+ -- The sort is to put them into canonical order
+ mk_import_items ns = [(n,v) | n <- sortLt lt_occ ns,
+ let v = lookupNameEnv version_env n `orElse`
+ pprPanic "mk_whats_imported" (ppr n)
+ ]
+ where
+ lt_occ n1 n2 = nameOccName n1 < nameOccName n2
+
+ maybe_export_vers | import_all_mod = Just (vers_exports version_info)
+ | otherwise = Nothing
in
- -- We find the gates by renaming the instance type with in a
- -- and returning the occurrence pool.
- initRnMS emptyRnEnv mod_name vanillaInterfaceMode (
- findOccurrencesRn (rnHsSigType (text "an instance decl") munged_inst_ty)
- ) `thenRn` \ gate_names ->
- returnRn (((mod_name, decl), gate_names) `consBag` insts)
-
-vanillaInterfaceMode = InterfaceMode Compulsory (\_ -> False)
+ returnRn import_info
\end{code}
-
-%********************************************************
-%* *
-\subsection{Loading usage information}
-%* *
-%********************************************************
+%*********************************************************
+%* *
+\subsection{Slurping declarations}
+%* *
+%*********************************************************
\begin{code}
-checkUpToDate :: Module -> RnMG Bool -- True <=> no need to recompile
-checkUpToDate mod_name
- = findAndReadIface doc_str mod_name HiFile `thenRn` \ read_result ->
-
- -- CHECK WHETHER WE HAVE IT ALREADY
- case read_result of
- Nothing -> -- Old interface file not found, so we'd better bail out
- traceRn (sep [ptext SLIT("Didnt find old iface"),
- pprModule mod_name]) `thenRn_`
- returnRn False
-
- Just (ParsedIface _ _ usages _ _ _ _ _)
- -> -- Found it, so now check it
- checkModUsage usages
- where
- -- Only look in current directory, with suffix .hi
- doc_str = sep [ptext SLIT("need usage info from"), pprModule mod_name]
-
-checkModUsage [] = returnRn True -- Yes! Everything is up to date!
-
-checkModUsage ((mod, hif, old_mod_vers, whats_imported) : rest)
- = loadInterface doc_str mod hif `thenRn` \ ifaces ->
- let
- Ifaces _ mod_map decls _ _ _ _ _ = ifaces
- maybe_new_mod_vers = lookupFM mod_map mod
- Just (_, new_mod_vers, _, _) = maybe_new_mod_vers
- in
- -- If we can't find a version number for the old module then
- -- bail out saying things aren't up to date
- if not (maybeToBool maybe_new_mod_vers) then
- traceRn (sep [ptext SLIT("Can't find version number for module"), pprModule mod]) `thenRn_`
- returnRn False
- else
+-------------------------------------------------------
+slurpImpDecls source_fvs
+ = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
- -- If the module version hasn't changed, just move on
- if new_mod_vers == old_mod_vers then
- traceRn (sep [ptext SLIT("Module version unchanged:"), pprModule mod]) `thenRn_`
- checkModUsage rest
- else
- traceRn (sep [ptext SLIT("Module version has changed:"), pprModule mod]) `thenRn_`
+ -- The current slurped-set records all local things
+ slurpSourceRefs source_fvs `thenRn` \ (decls, needed) ->
- -- Module version changed, so check entities inside
+ -- Then get everything else
+ closeDecls decls needed
- -- If the usage info wants to say "I imported everything from this module"
- -- it does so by making whats_imported equal to Everything
- -- In that case, we must recompile
- case whats_imported of {
- Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_`
- returnRn False; -- Bale out
- Specifically old_local_vers ->
+-------------------------------------------------------
+slurpSourceRefs :: FreeVars -- Variables referenced in source
+ -> RnMG ([RenamedHsDecl],
+ FreeVars) -- Un-satisfied needs
+-- The declaration (and hence home module) of each gate has
+-- already been loaded
- -- Non-empty usage list, so check item by item
- checkEntityUsage mod decls old_local_vers `thenRn` \ up_to_date ->
- if up_to_date then
- traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
- checkModUsage rest -- This one's ok, so check the rest
- else
- returnRn False -- This one failed, so just bail out now
- }
+slurpSourceRefs source_fvs
+ = go_outer [] -- Accumulating decls
+ emptyFVs -- Unsatisfied needs
+ emptyFVs -- Accumulating gates
+ (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
where
- doc_str = sep [ptext SLIT("need version info for"), pprModule mod]
-
+ -- The outer loop repeatedly slurps the decls for the current gates
+ -- and the instance decls
+
+ -- The outer loop is needed because consider
+
+ go_outer decls fvs all_gates []
+ = returnRn (decls, fvs)
+
+ go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet
+ = traceRn (text "go_outer" <+> ppr refs) `thenRn_`
+ foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) ->
+ getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls ->
+ rnIfaceInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
+ go_outer decls2 fvs2 (all_gates `plusFV` gates2)
+ (nameSetToList (gates2 `minusNameSet` all_gates))
+ -- Knock out the all_gates because even if we don't slurp any new
+ -- decls we can get some apparently-new gates from wired-in names
+
+ go_inner (decls, fvs, gates) wanted_name
+ = importDecl wanted_name `thenRn` \ import_result ->
+ case import_result of
+ AlreadySlurped -> returnRn (decls, fvs, gates)
+ InTypeEnv ty_thing -> returnRn (decls, fvs, gates `plusFV` getWiredInGates ty_thing)
+
+ HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (TyClD new_decl : decls,
+ fvs1 `plusFV` fvs,
+ gates `plusFV` getGates source_fvs new_decl)
+\end{code}
-checkEntityUsage mod decls []
- = returnRn True -- Yes! All up to date!
-checkEntityUsage mod decls ((occ_name,old_vers) : rest)
- = newImportedGlobalName mod occ_name HiFile `thenRn` \ name ->
- case lookupFM decls name of
+\begin{code}
+-------------------------------------------------------
+-- closeDecls keeps going until the free-var set is empty
+closeDecls decls needed
+ | not (isEmptyFVs needed)
+ = slurpDecls decls needed `thenRn` \ (decls1, needed1) ->
+ closeDecls decls1 needed1
- Nothing -> -- We used it before, but it ain't there now
- putDocRn (sep [ptext SLIT("No longer exported:"), ppr name]) `thenRn_`
- returnRn False
-
- Just (new_vers,_,_) -- It's there, but is it up to date?
- | new_vers == old_vers
- -- Up to date, so check the rest
- -> checkEntityUsage mod decls rest
-
- | otherwise
- -- Out of date, so bale out
- -> putDocRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_`
- returnRn False
+ | otherwise
+ = getImportedRules `thenRn` \ rule_decls ->
+ case rule_decls of
+ [] -> returnRn decls -- No new rules, so we are done
+ other -> rnIfaceDecls rnIfaceRuleDecl rule_decls `thenRn` \ rule_decls' ->
+ let
+ rule_fvs = plusFVs (map ruleDeclFVs rule_decls')
+ in
+ traceRn (text "closeRules" <+> ppr rule_decls' $$ fsep (map ppr (nameSetToList rule_fvs))) `thenRn_`
+ closeDecls (map RuleD rule_decls' ++ decls) rule_fvs
+
+
+
+-------------------------------------------------------
+-- Augment decls with any decls needed by needed.
+-- Return also free vars of the new decls (only)
+slurpDecls decls needed
+ = go decls emptyFVs (nameSetToList needed)
+ where
+ go decls fvs [] = returnRn (decls, fvs)
+ go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) ->
+ go decls1 fvs1 refs
+
+-------------------------------------------------------
+slurpDecl decls fvs wanted_name
+ = importDecl wanted_name `thenRn` \ import_result ->
+ case import_result of
+ -- Found a declaration... rename it
+ HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (TyClD new_decl:decls, fvs1 `plusFV` fvs)
+
+ -- No declaration... (wired in thing, or deferred, or already slurped)
+ other -> returnRn (decls, fvs)
+
+
+-------------------------------------------------------
+rnIfaceDecls rn decls = mapRn (rnIfaceDecl rn) decls
+rnIfaceDecl rn (mod, decl) = initIfaceRnMS mod (rn decl)
+
+rnIfaceInstDecls decls fvs gates inst_decls
+ = rnIfaceDecls rnInstDecl inst_decls `thenRn` \ inst_decls' ->
+ returnRn (map InstD inst_decls' ++ decls,
+ fvs `plusFV` plusFVs (map instDeclFVs inst_decls'),
+ gates `plusFV` plusFVs (map getInstDeclGates inst_decls'))
+
+rnIfaceTyClDecl (mod, decl) = initIfaceRnMS mod (rnTyClDecl decl) `thenRn` \ decl' ->
+ returnRn (decl', tyClDeclFVs decl')
\end{code}
-%*********************************************************
-%* *
-\subsection{Getting in a declaration}
-%* *
-%*********************************************************
-
\begin{code}
-importDecl :: Occurrence -> RnSMode -> RnMG (Maybe RdrNameHsDecl)
- -- Returns Nothing for a wired-in or already-slurped decl
-
-importDecl (name, loc) mode
- = checkSlurped name `thenRn` \ already_slurped ->
- if already_slurped then
--- traceRn (sep [text "Already slurped:", ppr name]) `thenRn_`
- returnRn Nothing -- Already dealt with
- else
- if isWiredInName name then
- getWiredInDecl name mode
- else
- getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod _ _ _ _ _ _ _ = ifaces
- mod = nameModule name
- in
- if mod == this_mod then -- Don't bring in decls from
- pprTrace "importDecl wierdness:" (ppr name) $
- returnRn Nothing -- the renamed module's own interface file
- --
- else
- getNonWiredInDecl name loc mode
+getSlurped
+ = getIfacesRn `thenRn` \ ifaces ->
+ returnRn (iSlurp ifaces)
+
+recordSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped),
+ iSlurp = slurped_names,
+ iVSlurp = (imp_mods, imp_names) })
+ avail
+ = ASSERT2( not (isLocalName (availName avail)), ppr avail )
+ ifaces { iDecls = (decls_map', n_slurped+1),
+ iSlurp = new_slurped_names,
+ iVSlurp = new_vslurp }
+ where
+ decls_map' = foldl delFromNameEnv decls_map (availNames avail)
+ main_name = availName avail
+ mod = nameModule main_name
+ new_slurped_names = addAvailToNameSet slurped_names avail
+ new_vslurp | isHomeModule mod = (imp_mods, addOneToNameSet imp_names main_name)
+ | otherwise = (extendModuleSet imp_mods mod, imp_names)
+
+recordLocalSlurps new_names
+ = getIfacesRn `thenRn` \ ifaces ->
+ setIfacesRn (ifaces { iSlurp = iSlurp ifaces `unionNameSets` new_names })
\end{code}
-\begin{code}
-getNonWiredInDecl :: Name -> SrcLoc -> RnSMode -> RnMG (Maybe RdrNameHsDecl)
-getNonWiredInDecl needed_name loc mode
- = traceRn doc_str `thenRn_`
- loadInterface doc_str mod (ifaceFlavour needed_name) `thenRn` \ (Ifaces _ _ decls _ _ _ _ _) ->
- case lookupFM decls needed_name of
-
- -- Special case for data/newtype type declarations
- Just (version, avail, TyD ty_decl) | is_data_or_newtype ty_decl
- -> getNonWiredDataDecl needed_name version avail ty_decl `thenRn` \ (avail', maybe_decl) ->
- recordSlurp (Just version) necessity avail' `thenRn_`
- returnRn maybe_decl
-
- Just (version,avail,decl)
- -> recordSlurp (Just version) necessity avail `thenRn_`
- returnRn (Just decl)
-
- Nothing -> -- Can happen legitimately for "Optional" occurrences
- case necessity of {
- Optional -> addWarnRn (getDeclWarn needed_name loc);
- other -> addErrRn (getDeclErr needed_name loc)
- } `thenRn_`
- returnRn Nothing
- where
- necessity = modeToNecessity mode
- doc_str = sep [ptext SLIT("need decl for"), ppr needed_name, ptext SLIT("needed at"), ppr loc]
- mod = nameModule needed_name
- is_data_or_newtype (TyData _ _ _ _ _ _ _ _) = True
- is_data_or_newtype other = False
-\end{code}
+%*********************************************************
+%* *
+\subsection{Extracting the `gates'}
+%* *
+%*********************************************************
-@getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
-It behaves exactly as if the wired in decl were actually in an interface file.
-Specifically,
+The gating story
+~~~~~~~~~~~~~~~~~
+We want to avoid sucking in too many instance declarations.
+An instance decl is only useful if the types and classes mentioned in
+its 'head' are all available in the program being compiled. E.g.
- * if the wired-in name is a data type constructor or a data constructor,
- it brings in the type constructor and all the data constructors; and
- marks as "occurrences" any free vars of the data con.
+ instance (..) => C (T1 a) (T2 b) where ...
- * similarly for synonum type constructor
+is only useful if C, T1 and T2 are all "available". So we keep
+instance decls that have been parsed from .hi files, but not yet
+slurped in, in a pool called the 'gated instance pool'.
+Each has its set of 'gates': {C, T1, T2} in the above example.
- * if the wired-in name is another wired-in Id, it marks as "occurrences"
- the free vars of the Id's type.
+More precisely, the gates of a module are the types and classes
+that are mentioned in:
- * it loads the interface file for the wired-in thing for the
- sole purpose of making sure that its instance declarations are available
+ a) the source code
+ b) the type of an Id that's mentioned in the source code
+ [includes constructors and selectors]
+ c) the RHS of a type synonym that is a gate
+ d) the superclasses of a class that is a gate
+ e) the context of an instance decl that is slurped in
-All this is necessary so that we know all types that are "in play", so
-that we know just what instances to bring into scope.
+We slurp in an instance decl from the gated instance pool iff
-\begin{code}
-getWiredInDecl name mode
- = initRnMS emptyRnEnv mod_name new_mode
- get_wired `thenRn` \ avail ->
- recordSlurp Nothing necessity avail `thenRn_`
+ all its gates are either in the gates of the module,
+ or are a previously-loaded class.
- -- Force in the home module in case it has instance decls for
- -- the thing we are interested in.
- --
- -- Mini hack 1: no point for non-tycons/class; and if we
- -- do this we find PrelNum trying to import PackedString,
- -- because PrelBase's .hi file mentions PackedString.unpackString
- -- But PackedString.hi isn't built by that point!
- --
- -- Mini hack 2; GHC is guaranteed not to have
- -- instance decls, so it's a waste of time to read it
- --
- -- NB: We *must* look at the availName of the slurped avail,
- -- not the name passed to getWiredInDecl! Why? Because if a data constructor
- -- or class op is passed to getWiredInDecl we'll pull in the whole data/class
- -- decl, and recordSlurp will record that fact. But since the data constructor
- -- isn't a tycon/class we won't force in the home module. And even if the
- -- type constructor/class comes along later, loadDecl will say that it's already
- -- been slurped, so getWiredInDecl won't even be called. Pretty obscure bug, this was.
- let
- main_name = availName avail
- main_is_tc = case avail of { AvailTC _ _ -> True; Avail _ -> False }
- mod = nameModule main_name
- doc_str = sep [ptext SLIT("need home module for wired in thing"), ppr name]
- in
- (if not main_is_tc || mod == pREL_GHC then
- returnRn ()
- else
- loadInterface doc_str mod (ifaceFlavour main_name) `thenRn_`
- returnRn ()
- ) `thenRn_`
+The latter constraint is because there might have been an instance
+decl slurped in during an earlier compilation, like this:
- returnRn Nothing -- No declaration to process further
- where
- necessity = modeToNecessity mode
- new_mode = case mode of
- InterfaceMode _ _ -> mode
- SourceMode -> vanillaInterfaceMode
+ instance Foo a => Baz (Maybe a) where ...
- get_wired | is_tycon -- ... a type constructor
- = get_wired_tycon the_tycon
+In the module being compiled we might need (Baz (Maybe T)), where T
+is defined in this module, and hence we need (Foo T). So @Foo@ becomes
+a gate. But there's no way to 'see' that, so we simply treat all
+previously-loaded classes as gates.
- | (isAlgCon the_id) -- ... a wired-in data constructor
- = get_wired_tycon (dataConTyCon the_id)
+Consructors and class operations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When we import a declaration like
- | otherwise -- ... a wired-in non data-constructor
- = get_wired_id the_id
+ data T = T1 Wibble | T2 Wobble
- mod_name = nameModule name
- maybe_wired_in_tycon = maybeWiredInTyConName name
- is_tycon = maybeToBool maybe_wired_in_tycon
- maybe_wired_in_id = maybeWiredInIdName name
- Just the_tycon = maybe_wired_in_tycon
- Just the_id = maybe_wired_in_id
+we don't want to treat @Wibble@ and @Wobble@ as gates {\em unless}
+@T1@, @T2@ respectively are mentioned by the user program. If only
+@T@ is mentioned we want only @T@ to be a gate; that way we don't suck
+in useless instance decls for (say) @Eq Wibble@, when they can't
+possibly be useful.
+And that's just what (b) says: we only treat T1's type as a gate if
+T1 is mentioned. getGates, which deals with decls we are slurping in,
+has to be a bit careful, because a mention of T1 will slurp in T's whole
+declaration.
-get_wired_id id
- = addImplicitOccsRn id_mentions `thenRn_`
- returnRn (Avail (getName id))
- where
- id_mentions = nameSetToList (namesOfType ty)
- ty = idType id
+-----------------------------
+@getGates@ takes a newly imported (and renamed) decl, and the free
+vars of the source program, and extracts from the decl the gate names.
-get_wired_tycon tycon
- | isSynTyCon tycon
- = addImplicitOccsRn (nameSetToList mentioned) `thenRn_`
- returnRn (AvailTC tc_name [tc_name])
- where
- tc_name = getName tycon
- (tyvars,ty) = getSynTyConDefn tycon
- mentioned = namesOfType ty `minusNameSet` mkNameSet (map getName tyvars)
-
-get_wired_tycon tycon
- | otherwise -- data or newtype
- = addImplicitOccsRn (nameSetToList mentioned) `thenRn_`
- returnRn (AvailTC tycon_name (tycon_name : map getName data_cons))
- where
- tycon_name = getName tycon
- data_cons = tyConDataCons tycon
- mentioned = foldr (unionNameSets . namesOfType . idType) emptyNameSet data_cons
-\end{code}
+\begin{code}
+getGates :: FreeVars -- Things mentioned in the source program
+ -> RenamedTyClDecl
+ -> FreeVars
+getGates source_fvs decl
+ = get_gates (\n -> n `elemNameSet` source_fvs) decl
-
-%*********************************************************
-%* *
-\subsection{Getting what a module exports}
-%* *
-%*********************************************************
+get_gates is_used (IfaceSig _ ty _ _)
+ = extractHsTyNames ty
-\begin{code}
-getInterfaceExports :: Module -> IfaceFlavour -> RnMG (Avails, [(OccName,Fixity)])
-getInterfaceExports mod as_source
- = loadInterface doc_str mod as_source `thenRn` \ (Ifaces _ mod_map _ _ _ _ _ _) ->
- case lookupFM mod_map mod of
- Nothing -> -- Not there; it must be that the interface file wasn't found;
- -- the error will have been reported already.
- -- (Actually loadInterface should put the empty export env in there
- -- anyway, but this does no harm.)
- returnRn ([],[])
-
- Just (_, _, avails, fixities) -> returnRn (avails, fixities)
+get_gates is_used (ClassDecl ctxt cls tvs _ sigs _ _ _ )
+ = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
+ (hsTyVarNames tvs)
+ `addOneToNameSet` cls)
+ `plusFV` maybe_double
where
- doc_str = sep [pprModule mod, ptext SLIT("is directly imported")]
-\end{code}
-
+ get (ClassOpSig n _ ty _)
+ | is_used n = extractHsTyNames ty
+ | otherwise = emptyFVs
+
+ -- If we load any numeric class that doesn't have
+ -- Int as an instance, add Double to the gates.
+ -- This takes account of the fact that Double might be needed for
+ -- defaulting, but we don't want to load Double (and all its baggage)
+ -- if the more exotic classes aren't used at all.
+ maybe_double | nameUnique cls `elem` fractionalClassKeys
+ = unitFV (getName doubleTyCon)
+ | otherwise
+ = emptyFVs
+
+get_gates is_used (TySynonym tycon tvs ty _)
+ = delListFromNameSet (extractHsTyNames ty) (hsTyVarNames tvs)
+ -- A type synonym type constructor isn't a "gate" for instance decls
+
+get_gates is_used (TyData _ ctxt tycon tvs cons _ _ _ _ _)
+ = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
+ (hsTyVarNames tvs)
+ `addOneToNameSet` tycon
+ where
+ get (ConDecl n _ tvs ctxt details _)
+ | is_used n
+ -- If the constructor is method, get fvs from all its fields
+ = delListFromNameSet (get_details details `plusFV`
+ extractHsCtxtTyNames ctxt)
+ (hsTyVarNames tvs)
+ get (ConDecl n _ tvs ctxt (RecCon fields) _)
+ -- Even if the constructor isn't mentioned, the fields
+ -- might be, as selectors. They can't mention existentially
+ -- bound tyvars (typechecker checks for that) so no need for
+ -- the deleteListFromNameSet part
+ = foldr (plusFV . get_field) emptyFVs fields
+
+ get other_con = emptyFVs
-%*********************************************************
-%* *
-\subsection{Data type declarations are handled specially}
-%* *
-%*********************************************************
+ get_details (VanillaCon tys) = plusFVs (map get_bang tys)
+ get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2
+ get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields]
-Data type declarations get special treatment. If we import a data type decl
-with all its constructors, we end up importing all the types mentioned in
-the constructors' signatures, and hence {\em their} data type decls, and so on.
-In effect, we get the transitive closure of data type decls. Worse, this drags
-in tons on instance decls, and their unfoldings, and so on.
+ get_field (fs,t) | any is_used fs = get_bang t
+ | otherwise = emptyFVs
-If only the type constructor is mentioned, then all this is a waste of time.
-If any of the data constructors are mentioned then we really have to
-drag in the whole declaration.
+ get_bang bty = extractHsTyNames (getBangType bty)
+\end{code}
-So when we import the type constructor for a @data@ or @newtype@ decl, we
-put it in the "deferred data/newtype decl" pile in Ifaces. Right at the end
-we slurp these decls, if they havn't already been dragged in by an occurrence
-of a constructor.
+@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded
+thing rather than a declaration.
\begin{code}
-getNonWiredDataDecl needed_name
- version
- avail@(AvailTC tycon_name _)
- ty_decl@(TyData new_or_data context tycon tyvars condecls derivings pragmas src_loc)
- | needed_name == tycon_name
- && opt_PruneTyDecls
- && not (nameUnique needed_name `elem` cCallishTyKeys)
- -- Hack! Don't prune these tycons whose constructors
- -- the desugarer must be able to see when desugaring
- -- a CCall. Ugh!
-
- = -- Need the type constructor; so put it in the deferred set for now
- getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod mod_map decls_fm slurped_names imp_names
- unslurped_insts deferred_data_decls inst_mods = ifaces
-
- new_ifaces = Ifaces this_mod mod_map decls_fm slurped_names imp_names
- unslurped_insts new_deferred_data_decls inst_mods
-
- no_constr_ty_decl = TyData new_or_data [] tycon tyvars [] derivings pragmas src_loc
- new_deferred_data_decls = addToFM deferred_data_decls tycon_name no_constr_ty_decl
- -- Nota bene: we nuke both the constructors and the context in the deferred decl.
- -- If we don't nuke the context then renaming the deferred data decls can give
- -- new unresolved names (for the classes). This could be handled, but there's
- -- no point. If the data type is completely abstract then we aren't interested
- -- its context.
- in
- setIfacesRn new_ifaces `thenRn_`
- returnRn (AvailTC tycon_name [tycon_name], Nothing)
-
- | otherwise
- = -- Need a data constructor, so delete the data decl from the deferred set if it's there
- getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod mod_map decls_fm slurped_names imp_names
- unslurped_insts deferred_data_decls inst_mods = ifaces
-
- new_ifaces = Ifaces this_mod mod_map decls_fm slurped_names imp_names
- unslurped_insts new_deferred_data_decls inst_mods
+getWiredInGates :: TyThing -> FreeVars
+-- The TyThing is one that we already have in our type environment, either
+-- a) because the TyCon or Id is wired in, or
+-- b) from a previous compile
+-- Either way, we might have instance decls in the (persistent) collection
+-- of parsed-but-not-slurped instance decls that should be slurped in.
+-- This might be the first module that mentions both the type and the class
+-- for that instance decl, even though both the type and the class were
+-- mentioned in other modules, and hence are in the type environment
+
+getWiredInGates (AnId the_id) = namesOfType (idType the_id)
+getWiredInGates (AClass cl) = emptyFVs -- The superclasses must also be previously
+ -- loaded, and hence are automatically gates
+getWiredInGates (ATyCon tc)
+ | isSynTyCon tc = delListFromNameSet (namesOfType ty) (map getName tyvars)
+ | otherwise = unitFV (getName tc)
+ where
+ (tyvars,ty) = getSynTyConDefn tc
- new_deferred_data_decls = delFromFM deferred_data_decls tycon_name
- in
- setIfacesRn new_ifaces `thenRn_`
- returnRn (avail, Just (TyD ty_decl))
+getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty
\end{code}
\begin{code}
-getDeferredDataDecls :: RnMG [(Name, RdrNameTyDecl)]
-getDeferredDataDecls
- = getIfacesRn `thenRn` \ (Ifaces _ _ _ _ _ _ deferred_data_decls _) ->
+getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameInstDecl)]
+getImportedInstDecls gates
+ = -- First, load any orphan-instance modules that aren't aready loaded
+ -- Orphan-instance modules are recorded in the module dependecnies
+ getIfacesRn `thenRn` \ ifaces ->
let
- deferred_list = fmToList deferred_data_decls
- trace_msg = hang (text "Slurping abstract data/newtype decls for: ")
- 4 (ppr (map fst deferred_list))
+ orphan_mods =
+ [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)]
in
- traceRn trace_msg `thenRn_`
- returnRn deferred_list
-\end{code}
-
-
-%*********************************************************
-%* *
-\subsection{Instance declarations are handled specially}
-%* *
-%*********************************************************
-
-\begin{code}
-getImportedInstDecls :: RnMG [(Module,RdrNameInstDecl)]
-getImportedInstDecls
- = -- First load any special-instance modules that aren't aready loaded
- getSpecialInstModules `thenRn` \ inst_mods ->
- mapRn load_it inst_mods `thenRn_`
+ loadOrphanModules orphan_mods `thenRn_`
-- Now we're ready to grab the instance declarations
-- Find the un-gated ones and return them,
-- removing them from the bag kept in Ifaces
- getIfacesRn `thenRn` \ ifaces ->
+ getIfacesRn `thenRn` \ ifaces ->
+ getTypeEnvRn `thenRn` \ lookup ->
let
- Ifaces this_mod mod_map decls slurped_names imp_names (insts, tycls_names) deferred_data_decls inst_mods = ifaces
-
- -- An instance decl is ungated if all its gates have been slurped
- select_ungated :: IfaceInst -- A gated inst decl
-
- -> ([(Module, RdrNameInstDecl)], [IfaceInst]) -- Accumulator
-
- -> ([(Module, RdrNameInstDecl)], -- The ungated ones
- [IfaceInst]) -- Still gated, but with
- -- depeleted gates
- select_ungated (decl,gates) (ungated_decls, gated_decls)
- | null remaining_gates
- = (decl : ungated_decls, gated_decls)
- | otherwise
- = (ungated_decls, (decl, remaining_gates) : gated_decls)
- where
- remaining_gates = filter (not . (`elemNameSet` tycls_names)) gates
-
- (un_gated_insts, still_gated_insts) = foldrBag select_ungated ([], []) insts
-
- new_ifaces = Ifaces this_mod mod_map decls slurped_names imp_names
- ((listToBag still_gated_insts), tycls_names)
- -- NB: don't throw away tycls_names; we may comre across more instance decls
- deferred_data_decls
- inst_mods
+ (decls, new_insts) = selectGated gates lookup (iInsts ifaces)
in
- traceRn (sep [text "getInstDecls:", fsep (map ppr (nameSetToList tycls_names))]) `thenRn_`
- setIfacesRn new_ifaces `thenRn_`
- returnRn un_gated_insts
+ setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
+
+ traceRn (sep [text "getImportedInstDecls:",
+ nest 4 (fsep (map ppr gate_list)),
+ text "Slurped" <+> int (length decls) <+> text "instance declarations",
+ nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
+ returnRn decls
where
- load_it mod = loadInterface (doc_str mod) mod HiFile
- doc_str mod = sep [pprModule mod, ptext SLIT("is a special-instance module")]
+ gate_list = nameSetToList gates
+ppr_brief_inst_decl (mod, InstDecl inst_ty _ _ _ _)
+ = case inst_ty of
+ HsForAllTy _ _ tau -> ppr tau
+ other -> ppr inst_ty
-getSpecialInstModules :: RnMG [Module]
-getSpecialInstModules
- = getIfacesRn `thenRn` \ ifaces ->
+getImportedRules :: RnMG [(Module,RdrNameRuleDecl)]
+getImportedRules
+ | opt_IgnoreIfacePragmas = returnRn []
+ | otherwise
+ = getIfacesRn `thenRn` \ ifaces ->
+ getTypeEnvRn `thenRn` \ lookup ->
let
- Ifaces _ _ _ _ _ _ _ inst_mods = ifaces
+ gates = iSlurp ifaces -- Anything at all that's been slurped
+ rules = iRules ifaces
+ (decls, new_rules) = selectGated gates lookup rules
+ in
+ if null decls then
+ returnRn []
+ else
+ setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
+ traceRn (sep [text "getImportedRules:",
+ text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
+ returnRn decls
+
+selectGated gates lookup (decl_bag, n_slurped)
+ -- Select only those decls whose gates are *all* in 'gates'
+ -- or are a class in 'lookup'
+#ifdef DEBUG
+ | opt_NoPruneDecls -- Just to try the effect of not gating at all
+ = let
+ decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all
in
- returnRn inst_mods
+ (decls, (emptyBag, n_slurped + length decls))
+
+ | otherwise
+#endif
+ = case foldrBag select ([], emptyBag) decl_bag of
+ (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls))
+ where
+ available n = n `elemNameSet` gates
+ || case lookup n of { Just (AClass c) -> True; other -> False }
+
+ select (reqd, decl) (yes, no)
+ | all available reqd = (decl:yes, no)
+ | otherwise = (yes, (reqd,decl) `consBag` no)
\end{code}
%*********************************************************
%* *
-\subsection{Keeping track of what we've slurped, and version numbers}
+\subsection{Getting in a declaration}
%* *
%*********************************************************
-getImportVersions figures out what the "usage information" for this moudule is;
-that is, what it must record in its interface file as the things it uses.
-It records:
- - anything reachable from its body code
- - any module exported with a "module Foo".
-
-Why the latter? Because if Foo changes then this module's export list
-will change, so we must recompile this module at least as far as
-making a new interface file --- but in practice that means complete
-recompilation.
-
-What about this?
- module A( f, g ) where module B( f ) where
- import B( f ) f = h 3
- g = ... h = ...
-
-Should we record B.f in A's usages? In fact we don't. Certainly, if
-anything about B.f changes than anyone who imports A should be recompiled;
-they'll get an early exit if they don't use B.f. However, even if B.f
-doesn't change at all, B.h may do so, and this change may not be reflected
-in f's version number. So there are two things going on when compiling module A:
-
-1. Are A.o and A.hi correct? Then we can bale out early.
-2. Should modules that import A be recompiled?
+\begin{code}
+importDecl :: Name -> RnMG ImportDeclResult
+
+data ImportDeclResult
+ = AlreadySlurped
+ | InTypeEnv TyThing
+ | HereItIs (Module, RdrNameTyClDecl)
+
+importDecl name
+ = -- STEP 1: Check if we've slurped it in while compiling this module
+ getIfacesRn `thenRn` \ ifaces ->
+ if name `elemNameSet` iSlurp ifaces then
+ returnRn AlreadySlurped
+ else
-For (1) it is slightly harmful to record B.f in A's usages, because a change in
-B.f's version will provoke full recompilation of A, producing an identical A.o,
-and A.hi differing only in its usage-version of B.f (which isn't used by any importer).
+ -- STEP 2: Check if it's already in the type environment
+ getTypeEnvRn `thenRn` \ lookup ->
+ case lookup name of {
+ Just ty_thing | name `elemNameEnv` wiredInThingEnv
+ -> -- When we find a wired-in name we must load its home
+ -- module so that we find any instance decls lurking therein
+ loadHomeInterface wi_doc name `thenRn_`
+ returnRn (InTypeEnv ty_thing)
-For (2), because of the tricky B.h question above, we ensure that A.hi is touched
-(even if identical to its previous version) if A's recompilation was triggered by
-an imported .hi file date change. Given that, there's no need to record B.f in
-A's usages.
+ | otherwise
+ -> returnRn (InTypeEnv ty_thing) ;
-On the other hand, if A exports "module B" then we *do* count module B among
-A's usages, because we must recompile A to ensure that A.hi changes appropriately.
+ Nothing ->
-\begin{code}
-getImportVersions :: Module -- Name of this module
- -> Maybe [IE any] -- Export list for this module
- -> RnMG (VersionInfo Name) -- Version info for these names
+ -- STEP 3: OK, we have to slurp it in from an interface file
+ -- First load the interface file
+ traceRn nd_doc `thenRn_`
+ loadHomeInterface nd_doc name `thenRn_`
+ getIfacesRn `thenRn` \ ifaces ->
-getImportVersions this_mod exports
- = getIfacesRn `thenRn` \ ifaces ->
+ -- STEP 4: Get the declaration out
let
- Ifaces _ mod_map _ _ imp_names _ _ _ = ifaces
+ (decls_map, _) = iDecls ifaces
+ in
+ case lookupNameEnv decls_map name of
+ Just (avail,_,decl)
+ -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
+ returnRn (HereItIs decl)
+
+ Nothing
+ -> addErrRn (getDeclErr name) `thenRn_`
+ returnRn AlreadySlurped
+ }
+ where
+ wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name
+ nd_doc = ptext SLIT("need decl for") <+> ppr name
- -- mv_map groups together all the things imported from a particular module.
- mv_map, mv_map_mod :: FiniteMap Module (WhatsImported Name)
+\end{code}
- mv_map_mod = foldl add_mod emptyFM export_mods
- -- mv_map_mod records all the modules that have a "module M"
- -- in this module's export list with an "Everything"
- mv_map = foldl add_mv mv_map_mod imp_names
- -- mv_map adds the version numbers of things exported individually
+%********************************************************
+%* *
+\subsection{Checking usage information}
+%* *
+%********************************************************
- mk_version_info (mod, local_versions)
- = case lookupFM mod_map mod of
- Just (hif, version, _, _) -> (mod, hif, version, local_versions)
- in
- returnRn (map mk_version_info (fmToList mv_map))
- where
- export_mods = case exports of
- Nothing -> []
- Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod]
+@recompileRequired@ is called from the HscMain. It checks whether
+a recompilation is required. It needs access to the persistent state,
+finder, etc, because it may have to load lots of interface files to
+check their versions.
- add_mv mv_map v@(name, version)
- = addToFM_C add_item mv_map mod (Specifically [v])
- where
- mod = nameModule name
+\begin{code}
+type RecompileRequired = Bool
+upToDate = False -- Recompile not required
+outOfDate = True -- Recompile required
+
+recompileRequired :: FilePath -- Only needed for debug msgs
+ -> Bool -- Source unchanged
+ -> ModIface -- Old interface
+ -> RnMG RecompileRequired
+recompileRequired iface_path source_unchanged iface
+ = traceHiDiffsRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_`
+
+ -- CHECK WHETHER THE SOURCE HAS CHANGED
+ if not source_unchanged then
+ traceHiDiffsRn (nest 4 (text "Source file changed or recompilation check turned off")) `thenRn_`
+ returnRn outOfDate
+ else
- add_item Everything _ = Everything
- add_item (Specifically xs) _ = Specifically (v:xs)
+ -- Source code unchanged and no errors yet... carry on
+ checkList [checkModUsage u | u <- mi_usages iface]
- add_mod mv_map mod = addToFM mv_map mod Everything
+checkList :: [RnMG RecompileRequired] -> RnMG RecompileRequired
+checkList [] = returnRn upToDate
+checkList (check:checks) = check `thenRn` \ recompile ->
+ if recompile then
+ returnRn outOfDate
+ else
+ checkList checks
\end{code}
-
+
\begin{code}
-checkSlurped name
- = getIfacesRn `thenRn` \ (Ifaces _ _ _ slurped_names _ _ _ _) ->
- returnRn (name `elemNameSet` slurped_names)
-
-getSlurpedNames :: RnMG NameSet
-getSlurpedNames
- = getIfacesRn `thenRn` \ ifaces ->
+checkModUsage :: ImportVersion Name -> RnMG RecompileRequired
+-- Given the usage information extracted from the old
+-- M.hi file for the module being compiled, figure out
+-- whether M needs to be recompiled.
+
+checkModUsage (mod_name, _, _, NothingAtAll)
+ -- If CurrentModule.hi contains
+ -- import Foo :: ;
+ -- then that simply records that Foo lies below CurrentModule in the
+ -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
+ -- In this case we don't even want to open Foo's interface.
+ = up_to_date (ptext SLIT("Nothing used from:") <+> ppr mod_name)
+
+checkModUsage (mod_name, _, is_boot, whats_imported)
+ = -- Load the imported interface is possible
+ -- We use tryLoadInterface, because failure is not an error
+ -- (might just be that the old .hi file for this module is out of date)
+ -- We use ImportByUser/ImportByUserSource as the 'from' flag,
+ -- a) because we need to know whether to load the .hi-boot file
+ -- b) because loadInterface things matters are amiss if we
+ -- ImportBySystem an interface it knows nothing about
let
- Ifaces _ _ _ slurped_names _ _ _ _ = ifaces
+ doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
+ from | is_boot = ImportByUserSource
+ | otherwise = ImportByUser
in
- returnRn slurped_names
-
-recordSlurp maybe_version necessity avail
- = {- traceRn (hsep [text "Record slurp:", pprAvail avail,
- -- NB PprForDebug prints export flag, which is too
- -- strict; it's a knot-tied thing in RnNames
- case necessity of {Compulsory -> text "comp"; Optional -> text "opt" } ]) `thenRn_`
- -}
- getIfacesRn `thenRn` \ ifaces ->
+ tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) ->
+
+ case maybe_err of {
+ Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
+ ppr mod_name]) ;
+ -- Couldn't find or parse a module mentioned in the
+ -- old interface file. Don't complain -- it might just be that
+ -- the current module doesn't need that import and it's been deleted
+
+ Nothing ->
let
- Ifaces this_mod mod_map decls slurped_names imp_names
- (insts, tycls_names) deferred_data_decls inst_mods = ifaces
-
- new_slurped_names = addAvailToNameSet slurped_names avail
-
- new_imp_names = case maybe_version of
- Just version -> (availName avail, version) : imp_names
- Nothing -> imp_names
-
- -- Add to the names that will let in instance declarations;
- -- but only (a) if it's a type/class
- -- (b) if it's compulsory (unless the test flag opt_PruneInstDecls is off)
- new_tycls_names = case avail of
- AvailTC tc _ | not opt_PruneInstDecls ||
- case necessity of {Optional -> False; Compulsory -> True }
- -> tycls_names `addOneToNameSet` tc
- otherwise -> tycls_names
-
- new_ifaces = Ifaces this_mod mod_map decls
- new_slurped_names
- new_imp_names
- (insts, new_tycls_names)
- deferred_data_decls
- inst_mods
+ new_vers = mi_version iface
+ new_decl_vers = vers_decls new_vers
in
- setIfacesRn new_ifaces
-\end{code}
+ case whats_imported of { -- NothingAtAll dealt with earlier
+ Everything old_mod_vers -> checkModuleVersion old_mod_vers new_vers `thenRn` \ recompile ->
+ if recompile then
+ out_of_date (ptext SLIT("...and I needed the whole module"))
+ else
+ returnRn upToDate ;
-%*********************************************************
-%* *
-\subsection{Getting binders out of a declaration}
-%* *
-%*********************************************************
+ Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers ->
-@getDeclBinders@ returns the names for a @RdrNameHsDecl@.
-It's used for both source code (from @availsFromDecl@) and interface files
-(from @loadDecl@).
+ -- CHECK MODULE
+ checkModuleVersion old_mod_vers new_vers `thenRn` \ recompile ->
+ if not recompile then
+ returnRn upToDate
+ else
+
+ -- CHECK EXPORT LIST
+ if checkExportList maybe_old_export_vers new_vers then
+ out_of_date (ptext SLIT("Export list changed"))
+ else
-It doesn't deal with source-code specific things: ValD, DefD. They
-are handled by the sourc-code specific stuff in RnNames.
+ -- CHECK RULES
+ if old_rule_vers /= vers_rules new_vers then
+ out_of_date (ptext SLIT("Rules changed"))
+ else
-\begin{code}
-getDeclBinders :: (RdrName -> SrcLoc -> RnMG Name) -- New-name function
- -> RdrNameHsDecl
- -> RnMG AvailInfo
-
-getDeclBinders new_name (TyD (TyData _ _ tycon _ condecls _ _ src_loc))
- = new_name tycon src_loc `thenRn` \ tycon_name ->
- getConFieldNames new_name condecls `thenRn` \ sub_names ->
- returnRn (AvailTC tycon_name (tycon_name : nub sub_names))
- -- The "nub" is because getConFieldNames can legitimately return duplicates,
- -- when a record declaration has the same field in multiple constructors
-
-getDeclBinders new_name (TyD (TySynonym tycon _ _ src_loc))
- = new_name tycon src_loc `thenRn` \ tycon_name ->
- returnRn (AvailTC tycon_name [tycon_name])
-
-getDeclBinders new_name (ClD (ClassDecl _ cname _ sigs _ _ tname dname src_loc))
- = new_name cname src_loc `thenRn` \ class_name ->
- new_name dname src_loc `thenRn` \ datacon_name ->
- new_name tname src_loc `thenRn` \ tycon_name ->
-
- -- Record the names for the class ops
- mapRn (getClassOpNames new_name) sigs `thenRn` \ sub_names ->
-
- returnRn (AvailTC class_name (class_name : datacon_name : tycon_name : sub_names))
-
-getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
- = new_name var src_loc `thenRn` \ var_name ->
- returnRn (Avail var_name)
-
-getDeclBinders new_name (DefD _) = returnRn NotAvailable
-getDeclBinders new_name (InstD _) = returnRn NotAvailable
-
-----------------
-getConFieldNames new_name (ConDecl con _ (RecCon fielddecls) src_loc : rest)
- = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
- getConFieldNames new_name rest `thenRn` \ ns ->
- returnRn (cfs ++ ns)
- where
- fields = concat (map fst fielddecls)
+ -- CHECK ITEMS ONE BY ONE
+ checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenRn` \ recompile ->
+ if recompile then
+ returnRn outOfDate -- This one failed, so just bail out now
+ else
+ up_to_date (ptext SLIT("...but the bits I use haven't."))
-getConFieldNames new_name (ConDecl con _ _ src_loc : rest)
- = new_name con src_loc `thenRn` \ n ->
- getConFieldNames new_name rest `thenRn` \ ns ->
- returnRn (n:ns)
+ }}
-getConFieldNames new_name [] = returnRn []
+------------------------
+checkModuleVersion old_mod_vers new_vers
+ | vers_module new_vers == old_mod_vers
+ = up_to_date (ptext SLIT("Module version unchanged"))
-getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc
-\end{code}
+ | otherwise
+ = out_of_date (ptext SLIT("Module version has changed"))
+------------------------
+checkExportList Nothing new_vers = upToDate
+checkExportList (Just v) new_vers = v /= vers_exports new_vers
-%*********************************************************
-%* *
-\subsection{Reading an interface file}
-%* *
-%*********************************************************
+------------------------
+checkEntityUsage new_vers (name,old_vers)
+ = case lookupNameEnv new_vers name of
-\begin{code}
-findAndReadIface :: SDoc -> Module
- -> IfaceFlavour
- -> RnMG (Maybe ParsedIface)
- -- Nothing <=> file not found, or unreadable, or illegible
- -- Just x <=> successfully found and parsed
-findAndReadIface doc_str mod_name as_source
- = traceRn trace_msg `thenRn_`
- getModuleHiMap `thenRn` \ himap ->
- case (lookupFM himap real_mod_name) of
- Nothing ->
- traceRn (ptext SLIT("...failed")) `thenRn_`
- returnRn Nothing
- Just fpath ->
- readIface fpath
-{-
- getSearchPathRn `thenRn` \ dirs ->
- try dirs
--}
- where
- real_mod_name =
- case as_source of
- HiBootFile -> 'b':moduleString mod_name
- HiFile -> moduleString mod_name
-
- trace_msg = sep [hsep [ptext SLIT("Reading"),
- case as_source of { HiBootFile -> ptext SLIT("[boot]"); other -> empty},
- ptext SLIT("interface for"),
- ptext mod_name <> semi],
- nest 4 (ptext SLIT("reason:") <+> doc_str)]
-
-{-
- -- For import {-# SOURCE #-} Foo, "as_source" will be True
- -- and we read Foo.hi-boot, not Foo.hi. This is used to break
- -- loops among modules.
- mod_suffix hi = case as_source of
- HiBootFile -> ".hi-boot" -- Ignore `ways' for boot files.
- HiFile -> hi
-
- try [] = traceRn (ptext SLIT("...failed")) `thenRn_`
- returnRn Nothing
-
- try ((dir,hisuf):dirs)
- = readIface file_path `thenRn` \ read_result ->
- case read_result of
- Nothing -> try dirs
- Just iface -> traceRn (ptext SLIT("...done")) `thenRn_`
- returnRn (Just iface)
- where
- file_path = dir ++ '/' : moduleString mod_name ++ (mod_suffix hisuf)
--}
-\end{code}
+ Nothing -> -- We used it before, but it ain't there now
+ out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
-@readIface@ tries just the one file.
+ Just new_vers -- It's there, but is it up to date?
+ | new_vers == old_vers -> returnRn upToDate
+ | otherwise -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
-\begin{code}
-readIface :: String -> RnMG (Maybe ParsedIface)
- -- Nothing <=> file not found, or unreadable, or illegible
- -- Just x <=> successfully found and parsed
-readIface file_path
- = ioToRnMG (hGetStringBuffer file_path) `thenRn` \ read_result ->
- case read_result of
- Right contents ->
- case parseIface contents (mkSrcLoc (mkFastString file_path) 1) of
- Failed err -> failWithRn Nothing err
- Succeeded (PIface iface) ->
- if opt_D_show_rn_imports then
- putDocRn (hcat[ptext SLIT("Read "), text file_path]) `thenRn_`
- returnRn (Just iface)
- else
- returnRn (Just iface)
-
- Left err ->
- if isDoesNotExistError err then
- returnRn Nothing
- else
- failWithRn Nothing (cannaeReadFile file_path err)
+up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate
+out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate
\end{code}
-%*********************************************************
-%* *
-\subsection{Utils}
-%* *
-%*********************************************************
-
-@mkSearchPath@ takes a string consisting of a colon-separated list
-of directories and corresponding suffixes, and turns it into a list
-of (directory, suffix) pairs. For example:
-
-\begin{verbatim}
- mkSearchPath "foo%.hi:.%.p_hi:baz%.mc_hi"
- = [("foo",".hi"),( ".", ".p_hi"), ("baz",".mc_hi")]
-\begin{verbatim}
-
-\begin{code}
-mkSearchPath :: Maybe String -> SearchPath
-mkSearchPath Nothing = [(".",".hi")]
-mkSearchPath (Just s)
- = go s
- where
- go "" = []
- go s =
- case span (/= '%') s of
- (dir,'%':rs) ->
- case span (/= ':') rs of
- (hisuf,_:rest) -> (dir,hisuf):go rest
- (hisuf,[]) -> [(dir,hisuf)]
-\end{code}
%*********************************************************
%* *
%*********************************************************
\begin{code}
-noIfaceErr filename
- = hcat [ptext SLIT("Could not find valid interface file "),
- quotes (pprModule filename)]
-
-cannaeReadFile file err
- = hcat [ptext SLIT("Failed in reading file: "),
- text file,
- ptext SLIT("; error="),
- text (show err)]
-
-getDeclErr name loc
- = sep [ptext SLIT("Failed to find interface decl for"),
- quotes (ppr name), ptext SLIT("needed at"), ppr loc]
-
-getDeclWarn name loc
- = sep [ptext SLIT("Warning: failed to find (optional) interface decl for"),
- quotes (ppr name), ptext SLIT("desired at"), ppr loc]
+getDeclErr name
+ = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
+ ptext SLIT("from module") <+> quotes (ppr (nameModule name))
+ ]
\end{code}
projects / ghc-hetmet.git / blobdiff