%
-% (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}
-#include "HsVersions.h"
-
-module RnIfaces (
- getInterfaceExports,
- getImportedInstDecls,
- getSpecialInstModules,
- importDecl, recordSlurp,
- getImportVersions,
-
- checkUpToDate,
+module RnIfaces
+ (
+ recordLocalSlurps,
+ mkImportInfo,
- getDeclBinders,
- mkSearchPath
- ) where
+ slurpImpDecls, closeDecls,
-IMP_Ubiq()
+ RecompileRequired, outOfDate, upToDate, recompileRequired
+ )
+where
+#include "HsVersions.h"
-import CmdLineOpts ( opt_HiSuffix, opt_HiSuffixPrelude )
-import HsSyn ( HsDecl(..), TyDecl(..), ClassDecl(..), HsTyVar, Bind, HsExpr, Sig(..), HsType(..),
- HsBinds(..), MonoBinds, DefaultDecl, ConDecl(..), BangType, IfaceSig(..),
- FixityDecl(..), Fixity, Fake, InPat, InstDecl(..), SYN_IE(Version), HsIdInfo,
- IE(..)
+import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls )
+import HscTypes
+import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..),
+ InstDecl(..), HsType(..), hsTyVarNames, getBangType
+ )
+import HsImpExp ( ImportDecl(..) )
+import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
+import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl,
+ extractHsTyNames, extractHsCtxtTyNames,
+ tyClDeclFVs, ruleDeclFVs, instDeclFVs
)
-import HsPragmas ( noGenPragmas )
-import RdrHsSyn ( SYN_IE(RdrNameHsDecl), SYN_IE(RdrNameInstDecl),
- RdrName, rdrNameOcc
+import RnHiFiles ( tryLoadInterface, loadHomeInterface,
+ loadOrphanModules
)
-import RnEnv ( newGlobalName, lookupRn, addImplicitOccsRn, availName, availNames, addAvailToNameSet )
-import RnSource ( rnHsType )
+import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl )
+import RnEnv
import RnMonad
-import ParseIface ( parseIface )
-
-import ErrUtils ( SYN_IE(Error), SYN_IE(Warning) )
-import FiniteMap ( FiniteMap, emptyFM, unitFM, lookupFM, addToFM, addToFM_C, addListToFM, fmToList )
-import Name ( Name {-instance NamedThing-}, Provenance, OccName(..),
- modAndOcc, occNameString, moduleString, pprModule,
- NameSet(..), emptyNameSet, unionNameSets, nameSetToList,
- minusNameSet, mkNameSet, elemNameSet,
- isWiredInName, maybeWiredInTyConName, maybeWiredInIdName
+import Id ( idType, idName, globalIdDetails )
+import IdInfo ( GlobalIdDetails(..) )
+import TcType ( namesOfType )
+import FieldLabel ( fieldLabelTyCon )
+import DataCon ( dataConTyCon )
+import TyCon ( isSynTyCon, getSynTyConDefn, tyConClass_maybe, tyConName )
+import Class ( className )
+import Name ( Name {-instance NamedThing-}, nameOccName,
+ nameModule, isLocalName, NamedThing(..)
)
-import Id ( GenId, Id(..), idType, dataConTyCon, isDataCon )
-import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn )
-import Type ( namesOfType )
-import TyVar ( GenTyVar )
-import SrcLoc ( mkIfaceSrcLoc )
-import PrelMods ( gHC__, isPreludeModule )
+import NameEnv ( elemNameEnv, delFromNameEnv, lookupNameEnv )
+import NameSet
+import Module ( Module, ModuleEnv,
+ moduleName, isHomeModule,
+ ModuleName, WhereFrom(..),
+ emptyModuleEnv,
+ extendModuleEnv_C, foldModuleEnv, lookupModuleEnv,
+ elemModuleSet, extendModuleSet
+ )
+import PrelInfo ( wiredInThingEnv, hasKey, fractionalClassKey, numClassKey,
+ integerTyConName, doubleTyConName )
+import Maybes ( maybeToBool )
+import FiniteMap
+import Outputable
import Bag
-import Maybes ( MaybeErr(..), expectJust, maybeToBool )
-import ListSetOps ( unionLists )
-import Pretty
-import PprStyle ( PprStyle(..) )
-import Util ( pprPanic, pprTrace )
-import StringBuffer ( StringBuffer, hGetStringBuffer, freeStringBuffer )
-
+import Util ( sortLt )
\end{code}
-
%*********************************************************
%* *
-\subsection{Loading a new interface file}
+\subsection{Keeping track of what we've slurped, and version numbers}
%* *
%*********************************************************
+mkImportInfo 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.
+
+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 indirectly. 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.
+
+The usage information records:
+
+\begin{itemize}
+\item (a) anything reachable from its body code
+\item (b) any module exported with a @module Foo@
+\item (c) anything reachable from an exported item
+\end{itemize}
+
+Why (b)? 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.
+
+Why (c)? Consider this:
+\begin{verbatim}
+ module A( f, g ) where | module B( f ) where
+ import B( f ) | f = h 3
+ g = ... | h = ...
+\end{verbatim}
+
+Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
+@A@'s usages? Our idea is that we aren't going to touch A.hi if it is
+*identical* to what it was before. If anything about @B.f@ changes
+than anyone who imports @A@ should be recompiled in case they use
+@B.f@ (they'll get an early exit if they don't). So, if anything
+about @B.f@ changes we'd better make sure that something in A.hi
+changes, and the convenient way to do that is to record the version
+number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
+complete recompiation of A, which is overkill but it's the only way to
+write a new, slightly different, A.hi.
+
+But the example is tricker. 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. But with -O, a module that imports A must be recompiled if
+@B.h@ changes! So A must record a dependency on @B.h@. So we treat
+the occurrence of @B.f@ in the export list *just as if* it were in the
+code of A, and thereby haul in all the stuff reachable from it.
+
+ *** Conclusion: if A mentions B.f in its export list,
+ behave just as if A mentioned B.f in its source code,
+ and slurp in B.f and all its transitive closure ***
+
+[NB: If B was compiled with -O, but A isn't, we should really *still*
+haul in all the unfoldings for B, in case the module that imports A *is*
+compiled with -O. I think this is the case.]
+
\begin{code}
-loadInterface :: Pretty -> Module -> RnMG Ifaces
-loadInterface doc_str load_mod
- = getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod mod_vers_map export_envs decls all_names imp_names insts inst_mods = ifaces
- in
- -- CHECK WHETHER WE HAVE IT ALREADY
- if maybeToBool (lookupFM export_envs load_mod)
- then
- returnRn ifaces -- Already in the cache; don't re-read it
- else
+mkImportInfo :: ModuleName -- Name of this module
+ -> [ImportDecl n] -- The import decls
+ -> RnMG [ImportVersion Name]
- -- READ THE MODULE IN
- findAndReadIface doc_str load_mod `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_export_envs = addToFM export_envs load_mod ([],[])
- new_ifaces = Ifaces this_mod mod_vers_map
- new_export_envs
- decls all_names imp_names insts 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
- mapRn loadExport exports `thenRn` \ avails_s ->
- foldlRn (loadDecl load_mod) decls rd_decls `thenRn` \ new_decls ->
- foldlRn (loadInstDecl load_mod) insts rd_insts `thenRn` \ new_insts ->
+mkImportInfo this_mod imports
+ = getIfacesRn `thenRn` \ ifaces ->
+ getHomeIfaceTableRn `thenRn` \ hit ->
let
- export_env = (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_vers_map load_mod mod_vers)
- (addToFM export_envs load_mod export_env)
- new_decls
- all_names imp_names
- new_insts
- new_inst_mods
- in
- setIfacesRn new_ifaces `thenRn_`
- returnRn new_ifaces
- }
-
-loadExport :: ExportItem -> RnMG [AvailInfo]
-loadExport (mod, entities)
- = mapRn load_entity entities
- where
- new_name occ = newGlobalName mod occ
-
--- The communcation between this little code fragment and the "entity" rule
--- in ParseIface.y is a bit gruesome. The idea is that things which are
--- destined to be AvailTCs show up as (occ, [non-empty-list]), whereas
--- things destined to be Avails show up as (occ, [])
-
- load_entity (occ, occs)
- = new_name occ `thenRn` \ name ->
- if null occs then
- returnRn (Avail name)
- else
- mapRn new_name occs `thenRn` \ names ->
- returnRn (AvailTC name names)
-
-loadDecl :: Module -> DeclsMap
- -> (Version, RdrNameHsDecl)
- -> RnMG DeclsMap
-loadDecl mod decls_map (version, decl)
- = getDeclBinders new_implicit_name decl `thenRn` \ avail ->
- returnRn (addListToFM decls_map
- [(name,(version,avail,decl)) | name <- availNames avail]
- )
- where
- new_implicit_name rdr_name loc = newGlobalName mod (rdrNameOcc rdr_name)
-
-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 ...
+ (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
+ --
+ -- 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
--
- -- 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
+ -- 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 = not_even_opened_imports ++ import_info1
+
+ -- Recall that iImpModInfo describes modules that have been mentioned
+ -- in the import lists of interfaces we have opened, but which we have
+ -- not even opened when compiling this module
+ not_even_opened_imports = [ (mod_name, orphans, is_boot, NothingAtAll)
+ | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ]
+
+
+ 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)
+ -- Since the module isn't in the mv_map, presumably we
+ -- didn't actually import anything at all from it
+ 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 = lookupVersion version_env 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 InterfaceMode (
- findOccurrencesRn (rnHsType munged_inst_ty)
- ) `thenRn` \ gate_names ->
- returnRn (((mod_name, decl), gate_names) `consBag` insts)
+ 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 `thenRn` \ read_result ->
- case read_result of
- Nothing -> -- Old interface file not found, so we'd better bail out
- traceRn (ppSep [ppPStr SLIT("Didnt find old iface"),
- pprModule PprDebug 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 = ppSep [ppPStr SLIT("Need usage info from"), pprModule PprDebug mod_name]
+-------------------------------------------------------
+slurpImpDecls source_fvs
+ = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
+ -- The current slurped-set records all local things
+ slurpSourceRefs source_fvs `thenRn` \ (decls, needed) ->
-checkModUsage [] = returnRn True -- Yes! Everything is up to date!
+ -- Then get everything else
+ closeDecls decls needed
-checkModUsage ((mod, old_mod_vers, old_local_vers) : rest)
- = loadInterface doc_str mod `thenRn` \ ifaces ->
- let
- Ifaces _ mod_vers _ decls _ _ _ _ = ifaces
- maybe_new_mod_vers = lookupFM mod_vers 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
- returnRn False
- else
- -- If the module version hasn't changed, just move on
- if new_mod_vers == old_mod_vers then
- traceRn (ppSep [ppPStr SLIT("Module version unchanged:"), pprModule PprDebug mod]) `thenRn_`
- checkModUsage rest
- else
- traceRn (ppSep [ppPStr SLIT("Module version has changed:"), pprModule PprDebug mod]) `thenRn_`
+-------------------------------------------------------
+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
- -- New module version, so check entities inside
- checkEntityUsage mod decls old_local_vers `thenRn` \ up_to_date ->
- if up_to_date then
- traceRn (ppPStr 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 = ppSep [ppPStr SLIT("need version info for"), pprModule PprDebug mod]
+ -- The outer loop repeatedly slurps the decls for the current gates
+ -- and the instance decls
+ -- The outer loop is needed because consider
+ -- instance Foo a => Baz (Maybe a) where ...
+ -- It may be that Baz and Maybe are used in the source module,
+ -- but not Foo; so we need to chase Foo too.
+ --
+ -- We also need to follow superclass refs. In particular, 'chasing Foo' must
+ -- include actually getting in Foo's class decl
+ -- class Wib a => Foo a where ..
+ -- so that its superclasses are discovered. The point is that Wib is a gate too.
+ -- We do this for tycons too, so that we look through type synonyms.
+
+ 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
+ -- and we get an infinite loop
+
+ 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)
- = newGlobalName mod occ_name `thenRn` \ name ->
- case lookupFM decls name of
- Nothing -> -- We used it before, but it ain't there now
- traceRn (ppSep [ppPStr SLIT("...and this no longer exported:"), ppr PprDebug 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
- -> traceRn (ppSep [ppPStr SLIT("...and this is out of date:"), ppr PprDebug name]) `thenRn_`
- returnRn False
+\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
+
+ | 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 :: Name -> Necessity -> RnMG (Maybe RdrNameHsDecl)
- -- Returns Nothing for a wired-in or already-slurped decl
+recordDeclSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped),
+ iSlurp = slurped_names,
+ iVSlurp = vslurp })
+ avail
+ = ASSERT2( not (isLocalName (availName avail)), ppr avail )
+ ifaces { iDecls = (new_decls_map, n_slurped+1),
+ iSlurp = new_slurped_names,
+ iVSlurp = updateVSlurp vslurp (availName avail) }
+ where
+ new_decls_map = foldl delFromNameEnv decls_map (availNames avail)
+ new_slurped_names = addAvailToNameSet slurped_names avail
-importDecl name necessity
- = checkSlurped name `thenRn` \ already_slurped ->
- if already_slurped then
- returnRn Nothing -- Already dealt with
- else
- if isWiredInName name then
- getWiredInDecl name
- else
- getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod _ _ _ _ _ _ _ = ifaces
- (mod,_) = modAndOcc name
- in
- if mod == this_mod then -- Don't bring in decls from
- pprTrace "importDecl wierdness:" (ppr PprDebug name) $
- returnRn Nothing -- the renamed module's own interface file
- --
- else
- getNonWiredInDecl name necessity
-\end{code}
+-- recordTypeEnvSlurp is used when we slurp something that's
+-- already in the type environment, that was not slurped in an earlier compilation.
+-- We record it in the iVSlurp set, because that's used to
+-- generate usage information
-\begin{code}
-getNonWiredInDecl :: Name -> Necessity -> RnMG (Maybe RdrNameHsDecl)
-getNonWiredInDecl name necessity
- = traceRn doc_str `thenRn_`
- loadInterface doc_str mod `thenRn` \ (Ifaces _ _ _ decls _ _ _ _) ->
- case lookupFM decls name of
-
- Just (version,avail,decl) -> recordSlurp (Just version) avail `thenRn_`
- returnRn (Just decl)
-
- Nothing -> -- Can happen legitimately for "Optional" occurrences
- case necessity of {
- Optional -> addWarnRn (getDeclWarn name);
- other -> addErrRn (getDeclErr name)
- } `thenRn_`
- returnRn Nothing
+recordTypeEnvSlurp ifaces ty_thing
+ = ifaces { iVSlurp = updateVSlurp (iVSlurp ifaces) (get_main_name ty_thing) }
where
- doc_str = ppSep [ppPStr SLIT("Need decl for"), ppr PprDebug name]
- (mod,_) = modAndOcc name
+ -- Tiresomely, we must get the "main" name for the
+ -- thing, because that's what VSlurp contains, and what
+ -- is recorded in the usage information
+ get_main_name (AClass cl) = className cl
+ get_main_name (ATyCon tc)
+ | Just clas <- tyConClass_maybe tc = get_main_name (AClass clas)
+ | otherwise = tyConName tc
+ get_main_name (AnId id)
+ = case globalIdDetails id of
+ DataConId dc -> get_main_name (ATyCon (dataConTyCon dc))
+ DataConWrapId dc -> get_main_name (ATyCon (dataConTyCon dc))
+ RecordSelId lbl -> get_main_name (ATyCon (fieldLabelTyCon lbl))
+ other -> idName id
+
+updateVSlurp (imp_mods, imp_names) main_name
+ | isHomeModule mod = (imp_mods, addOneToNameSet imp_names main_name)
+ | otherwise = (extendModuleSet imp_mods mod, imp_names)
+ where
+ mod = nameModule main_name
+
+recordLocalSlurps new_names
+ = getIfacesRn `thenRn` \ ifaces ->
+ setIfacesRn (ifaces { iSlurp = iSlurp ifaces `unionNameSets` new_names })
\end{code}
-@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,
- * 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.
- * similarly for synonum type constructor
+%*********************************************************
+%* *
+\subsection{Extracting the `gates'}
+%* *
+%*********************************************************
+
+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 another wired-in Id, it marks as "occurrences"
- the free vars of the Id's type.
+ instance (..) => C (T1 a) (T2 b) where ...
- * it loads the interface file for the wired-in thing for the
- sole purpose of making sure that its instance declarations are available
+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.
-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.
+More precisely, the gates of a module are the types and classes
+that are mentioned in:
+
+ 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
+
+We slurp in an instance decl from the gated instance pool iff
-\begin{code}
-getWiredInDecl name
- = -- Force in the home module in case it has instance decls for
- -- the thing we are interested in
- (if not is_tycon || mod == gHC__ then
- returnRn () -- Mini hack 1: no point for non-tycons; 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
- else
- loadInterface doc_str mod `thenRn_`
- returnRn ()
- ) `thenRn_`
+ all its gates are either in the gates of the module,
+ or are a previously-loaded class.
- get_wired `thenRn` \ avail ->
- recordSlurp Nothing avail `thenRn_`
- returnRn Nothing -- No declaration to process further
- where
- doc_str = ppSep [ppPStr SLIT("Need home module for wired in thing"), ppr PprDebug name]
- (mod,_) = modAndOcc 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
+The latter constraint is because there might have been an instance
+decl slurped in during an earlier compilation, like this:
- get_wired | is_tycon -- ... a type constructor
- = get_wired_tycon the_tycon
- -- Else, must be a wired-in-Id
+ instance Foo a => Baz (Maybe a) where ...
- | (isDataCon the_id) -- ... a wired-in data constructor
- = get_wired_tycon (dataConTyCon the_id)
+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
- | otherwise -- ... a wired-in non data-constructor
- = get_wired_id the_id
+ we simply treat all previously-loaded classes as gates.
+Consructors and class operations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When we import a declaration like
-get_wired_id id
- = addImplicitOccsRn (nameSetToList id_mentioned) `thenRn_`
- returnRn (Avail (getName id))
- where
- id_mentioned = namesOfType (idType id)
+ data T = T1 Wibble | T2 Wobble
-get_wired_tycon tycon
- | isSynTyCon tycon
- = addImplicitOccsRn (nameSetToList mentioned) `thenRn_`
- returnRn (Avail (getName tycon))
- where
- (tyvars,ty) = getSynTyConDefn tycon
- mentioned = namesOfType ty `minusNameSet` mkNameSet (map getName tyvars)
+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.
-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}
+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.
+-----------------------------
+@getGates@ takes a newly imported (and renamed) decl, and the free
+vars of the source program, and extracts from the decl the gate names.
\begin{code}
-checkSlurped name
- = getIfacesRn `thenRn` \ (Ifaces _ _ _ _ slurped_names _ _ _) ->
- returnRn (name `elemNameSet` slurped_names)
+getGates :: FreeVars -- Things mentioned in the source program
+ -- Used for the cunning "constructors and
+ -- class ops" story described 10 lines above.
+ -> RenamedTyClDecl
+ -> FreeVars
-recordSlurp maybe_version avail
- = getIfacesRn `thenRn` \ ifaces ->
- let
- Ifaces this_mod mod_vers export_envs decls slurped_names imp_names insts 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
-
- new_ifaces = Ifaces this_mod mod_vers export_envs decls
- new_slurped_names
- new_imp_names
- insts
- inst_mods
- in
- setIfacesRn new_ifaces
+getGates source_fvs decl
+ = get_gates (\n -> n `elemNameSet` source_fvs) decl
+
+get_gates is_used (ForeignType {tcdName = tycon}) = unitNameSet tycon
+get_gates is_used (IfaceSig {tcdType = ty}) = extractHsTyNames ty
+
+get_gates is_used (ClassDecl { tcdCtxt = ctxt, tcdName = cls, tcdTyVars = tvs, tcdSigs = sigs})
+ = (super_cls_and_sigs `addOneToNameSet` cls) `unionNameSets`
+ implicitClassGates cls
+ where
+ super_cls_and_sigs = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
+ (hsTyVarNames tvs)
+ get (ClassOpSig n _ ty _)
+ | is_used n = extractHsTyNames ty
+ | otherwise = emptyFVs
+
+get_gates is_used (TySynonym {tcdTyVars = tvs, tcdSynRhs = ty})
+ = delListFromNameSet (extractHsTyNames ty) (hsTyVarNames tvs)
+ -- A type synonym type constructor isn't a "gate" for instance decls
+
+get_gates is_used (TyData {tcdCtxt = ctxt, tcdName = tycon, tcdTyVars = tvs, tcdCons = 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
+
+ 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]
+
+ get_field (fs,t) | any is_used fs = get_bang t
+ | otherwise = emptyFVs
+
+ get_bang bty = extractHsTyNames (getBangType bty)
+
+implicitClassGates :: Name -> FreeVars
+implicitClassGates cls
+ -- If we load class Num, add Integer to the free gates
+ -- This takes account of the fact that Integer might be needed for
+ -- defaulting, but we don't want to load Integer (and all its baggage)
+ -- if there's no numeric stuff needed.
+ -- Similarly for class Fractional and Double
+ --
+ -- NB: adding T to the gates will force T to be loaded
+ --
+ -- NB: If we load (say) Floating, we'll end up loading Fractional too,
+ -- since Fractional is a superclass of Floating
+ | cls `hasKey` numClassKey = unitFV integerTyConName
+ | cls `hasKey` fractionalClassKey = unitFV doubleTyConName
+ | otherwise = emptyFVs
\end{code}
-
-%*********************************************************
-%* *
-\subsection{Getting other stuff}
-%* *
-%*********************************************************
+
+@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded
+thing rather than a declaration.
\begin{code}
-getInterfaceExports :: Module -> RnMG (Avails, [(OccName,Fixity)])
-getInterfaceExports mod
- = loadInterface doc_str mod `thenRn` \ (Ifaces _ _ export_envs _ _ _ _ _) ->
- case lookupFM export_envs 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 stuff -> returnRn stuff
+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) = implicitClassGates (getName cl)
+ -- The superclasses must also be previously
+ -- loaded, and hence are automatically gates
+ -- All previously-loaded classes are automatically gates
+ -- See "The gating story" above
+getWiredInGates (ATyCon tc)
+ | isSynTyCon tc = delListFromNameSet (namesOfType ty) (map getName tyvars)
+ | otherwise = unitFV (getName tc)
where
- doc_str = ppSep [pprModule PprDebug mod, ppPStr SLIT("is directly imported")]
+ (tyvars,ty) = getSynTyConDefn tc
+getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty
+\end{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_`
+\begin{code}
+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
+ orphan_mods =
+ [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)]
+ in
+ 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_vers export_envs decls slurped_names imp_names insts inst_mods = ifaces
+ available n
+ | n `elemNameSet` gates = True
+ | otherwise = case lookup n of { Just (AClass c) -> True; other -> False }
+ -- See "The gating story" above for the AClass thing
- -- 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` slurped_names)) gates
-
- (un_gated_insts, still_gated_insts) = foldrBag select_ungated ([], []) insts
-
- new_ifaces = Ifaces this_mod mod_vers export_envs decls slurped_names imp_names
- (listToBag still_gated_insts)
- inst_mods
+ (decls, new_insts) = selectGated available (iInsts ifaces)
in
- 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
- doc_str mod = ppSep [pprModule PprDebug mod, ppPStr 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
+ -- Slurp rules for anything that is slurped,
+ -- either now or previously
+ gates = iSlurp ifaces
+ available n = n `elemNameSet` gates || maybeToBool (lookup n)
+ (decls, new_rules) = selectGated available (iRules ifaces)
in
- returnRn inst_mods
-\end{code}
+ 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 :: (Name->Bool) -> GatedDecls d
+ -> ([(Module,d)], GatedDecls d)
+selectGated available (decl_bag, n_slurped)
+ -- Select only those decls whose gates are *all* available
+#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
+ (decls, (emptyBag, n_slurped + length decls))
-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".
+ | otherwise
+#endif
+ = case foldrBag select ([], emptyBag) decl_bag of
+ (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls))
+ where
+ select (gate_fn, decl) (yes, no)
+ | gate_fn available = (decl:yes, no)
+ | otherwise = (yes, (gate_fn,decl) `consBag` no)
+\end{code}
-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 = ...
+%*********************************************************
+%* *
+\subsection{Getting in a declaration}
+%* *
+%*********************************************************
-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:
+\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
-1. Are A.o and A.hi correct? Then we can bale out early.
-2. Should modules that import A be recompiled?
-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
+ -> -- Very important: record that we've seen it
+ -- See comments with recordTypeEnvSlurp
+ setIfacesRn (recordTypeEnvSlurp ifaces ty_thing) `thenRn_`
+ 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_versions_map _ _ _ imp_names _ _ = ifaces
- mod_version mod = expectJust "import_versions" (lookupFM mod_versions_map mod)
-
- -- mv_map groups together all the things imported from a particular module.
- mv_map, mv_map_mod :: FiniteMap Module [LocalVersion Name]
-
- 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
-
- mv_map = foldl add_mv mv_map_mod imp_names
- -- mv_map adds the version numbers of things exported individually
+ (decls_map, _) = iDecls ifaces
in
- returnRn [ (mod, mod_version mod, local_versions)
- | (mod, local_versions) <- fmToList mv_map
- ]
+ case lookupNameEnv decls_map name of
+ Just (avail,_,decl) -> setIfacesRn (recordDeclSlurp ifaces avail) `thenRn_`
+ returnRn (HereItIs decl)
+ Nothing -> addErrRn (getDeclErr name) `thenRn_`
+ returnRn AlreadySlurped
+ }
where
- export_mods = case exports of
- Nothing -> []
- Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod]
-
- add_mv mv_map v@(name, version)
- = addToFM_C (\ ls _ -> (v:ls)) mv_map mod [v]
- where
- (mod,_) = modAndOcc name
+ wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name
+ nd_doc = ptext SLIT("need decl for") <+> ppr name
- add_mod mv_map mod = addToFM mv_map mod []
\end{code}
-%*********************************************************
+
+%********************************************************
%* *
-\subsection{Getting binders out of a declaration}
+\subsection{Checking usage information}
%* *
-%*********************************************************
-
-@getDeclBinders@ returns the names for a @RdrNameHsDecl@.
-It's used for both source code (from @availsFromDecl@) and interface files
-(from @loadDecl@).
+%********************************************************
-It doesn't deal with source-code specific things: ValD, DefD. They
-are handled by the sourc-code specific stuff in RnNames.
+@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.
\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 : sub_names))
-
-getDeclBinders new_name (TyD (TyNew _ tycon _ (NewConDecl con _ con_loc) _ _ src_loc))
- = new_name tycon src_loc `thenRn` \ tycon_name ->
- new_name con src_loc `thenRn` \ con_name ->
- returnRn (AvailTC tycon_name [tycon_name, con_name])
-
-getDeclBinders new_name (TyD (TySynonym tycon _ _ src_loc))
- = new_name tycon src_loc `thenRn` \ tycon_name ->
- returnRn (Avail tycon_name)
-
-getDeclBinders new_name (ClD (ClassDecl _ cname _ sigs _ _ src_loc))
- = new_name cname src_loc `thenRn` \ class_name ->
- mapRn (getClassOpNames new_name) sigs `thenRn` \ sub_names ->
- returnRn (AvailTC class_name (class_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 _ src_loc : rest)
- = new_name con src_loc `thenRn` \ n ->
- getConFieldNames new_name rest `thenRn` \ ns ->
- returnRn (n:ns)
-
-getConFieldNames new_name (NewConDecl con _ src_loc : rest)
- = new_name con src_loc `thenRn` \ n ->
- getConFieldNames new_name rest `thenRn` \ ns ->
- returnRn (n:ns)
-
-getConFieldNames new_name (ConOpDecl _ con _ src_loc : rest)
- = new_name con src_loc `thenRn` \ n ->
- getConFieldNames new_name rest `thenRn` \ ns ->
- returnRn (n:ns)
-
-getConFieldNames new_name (RecConDecl con 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)
+type RecompileRequired = Bool
+upToDate = False -- Recompile not required
+outOfDate = True -- Recompile required
+
+recompileRequired :: FilePath -- Only needed for debug msgs
+ -> ModIface -- Old interface
+ -> RnMG RecompileRequired
+recompileRequired iface_path iface
+ = traceHiDiffsRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_`
+
+ -- Source code unchanged and no errors yet... carry on
+ checkList [checkModUsage u | u <- mi_usages iface]
+
+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}
+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
+ doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
+ from | is_boot = ImportByUserSource
+ | otherwise = ImportByUser
+ in
+ traceHiDiffsRn (text "Checking usages for module" <+> ppr mod_name) `thenRn_`
+ tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) ->
-getConFieldNames new_name [] = returnRn []
+ 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
-getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc
-\end{code}
+ Nothing ->
+ let
+ new_vers = mi_version iface
+ new_decl_vers = vers_decls new_vers
+ in
+ 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{Reading an interface file}
-%* *
-%*********************************************************
+ Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers ->
-\begin{code}
-findAndReadIface :: Pretty -> Module -> RnMG (Maybe ParsedIface)
- -- Nothing <=> file not found, or unreadable, or illegible
- -- Just x <=> successfully found and parsed
-findAndReadIface doc_str mod
- = traceRn trace_msg `thenRn_`
- getSearchPathRn `thenRn` \ dirs ->
- try dirs dirs
- where
- trace_msg = ppHang (ppBesides [ppPStr SLIT("Reading interface for "),
- pprModule PprDebug mod, ppSemi])
- 4 (ppBesides [ppPStr SLIT("reason: "), doc_str])
-
- mod_str = moduleString mod
- hisuf =
- if isPreludeModule mod then
- case opt_HiSuffixPrelude of { Just hisuf -> hisuf; _ -> ".hi"}
- else
- case opt_HiSuffix of {Just hisuf -> hisuf; _ -> ".hi"}
-
- try all_dirs [] = traceRn (ppPStr SLIT("...failed")) `thenRn_`
- returnRn Nothing
-
- try all_dirs (dir:dirs)
- = readIface file_path `thenRn` \ read_result ->
- case read_result of
- Nothing -> try all_dirs dirs
- Just iface -> traceRn (ppPStr SLIT("...done")) `thenRn_`
- returnRn (Just iface)
- where
- file_path = dir ++ "/" ++ moduleString mod ++ hisuf
-\end{code}
+ -- 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
-@readIface@ trys just one file.
+ -- CHECK RULES
+ if old_rule_vers /= vers_rules new_vers then
+ out_of_date (ptext SLIT("Rules changed"))
+ else
-\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 ->
---OLD: = ioToRnMG (readFile file_path) `thenRn` \ read_result ->
- case read_result of
- Right contents -> case parseIface contents of
- Failed err -> --ioToRnMG (freeStringBuffer contents) `thenRn` \ _ ->
- failWithRn Nothing err
- Succeeded iface -> --ioToRnMG (freeStringBuffer contents) `thenRn` \ _ ->
- returnRn (Just iface)
-
- Left (NoSuchThing _) -> returnRn Nothing
-
- Left err -> failWithRn Nothing
- (cannaeReadFile file_path err)
+ -- 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."))
-\end{code}
+ }}
-mkSearchPath takes a string consisting of a colon-separated list of directories, and turns it into
-a list of directories. For example:
+------------------------
+checkModuleVersion old_mod_vers new_vers
+ | vers_module new_vers == old_mod_vers
+ = up_to_date (ptext SLIT("Module version unchanged"))
- mkSearchPath "foo:.:baz" = ["foo", ".", "baz"]
+ | otherwise
+ = out_of_date (ptext SLIT("Module version has changed"))
-\begin{code}
-mkSearchPath :: Maybe String -> SearchPath
-mkSearchPath Nothing = ["."]
-mkSearchPath (Just s)
- = go s
- where
- go "" = []
- go s = first : go (drop 1 rest)
- where
- (first,rest) = span (/= ':') s
+------------------------
+checkExportList Nothing new_vers = upToDate
+checkExportList (Just v) new_vers = v /= vers_exports new_vers
+
+------------------------
+checkEntityUsage new_vers (name,old_vers)
+ = case lookupNameEnv new_vers name of
+
+ Nothing -> -- We used it before, but it ain't there now
+ out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
+
+ Just new_vers -- It's there, but is it up to date?
+ | new_vers == old_vers -> traceHiDiffsRn (text "Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenRn_`
+ returnRn upToDate
+ | otherwise -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name, ppr
+ old_vers, ptext SLIT("->"), ppr new_vers])
+
+up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate
+out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate
\end{code}
+
%*********************************************************
-%* *
+%* *
\subsection{Errors}
-%* *
+%* *
%*********************************************************
\begin{code}
-noIfaceErr mod sty
- = ppBesides [ppPStr SLIT("Could not find valid interface file for "), ppQuote (pprModule sty mod)]
--- , ppStr " in"]) 4 (ppAboves (map ppStr dirs))
-
-cannaeReadFile file err sty
- = ppBesides [ppPStr SLIT("Failed in reading file: "), ppStr file, ppPStr SLIT("; error="), ppStr (show err)]
-
-getDeclErr name sty
- = ppSep [ppPStr SLIT("Failed to find interface decl for"), ppr sty name]
-
-getDeclWarn name sty
- = ppSep [ppPStr SLIT("Warning: failed to find (optional) interface decl for"), ppr sty name]
+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