\section[RnIfaces]{Cacheing and Renaming of Interfaces}
\begin{code}
-module RnIfaces (
- getInterfaceExports,
- getImportedInstDecls, getImportedRules,
- lookupFixity, loadHomeInterface,
- importDecl, recordSlurp,
- getImportVersions, getSlurped,
+module RnIfaces
+ (
+ recordLocalSlurps,
+ mkImportInfo,
- checkUpToDate,
+ slurpImpDecls, closeDecls,
- getDeclBinders, getDeclSysBinders,
- removeContext -- removeContext probably belongs somewhere else
- ) where
+ RecompileRequired, outOfDate, upToDate, recompileRequired
+ )
+where
#include "HsVersions.h"
-import CmdLineOpts ( opt_NoPruneDecls, opt_IgnoreIfacePragmas )
-import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..),
- HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
- ForeignDecl(..), ForKind(..), isDynamic,
- FixitySig(..), RuleDecl(..),
- isClassOpSig
+import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls )
+import HscTypes
+import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..),
+ InstDecl(..), HsType(..), hsTyVarNames, getBangType
)
-import BasicTypes ( Version, NewOrData(..), defaultFixity )
-import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyClDecl, RdrNameRuleDecl,
- extractHsTyRdrNames
+import HsImpExp ( ImportDecl(..) )
+import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
+import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl,
+ extractHsTyNames, extractHsCtxtTyNames,
+ tyClDeclFVs, ruleDeclFVs, instDeclFVs
)
-import RnEnv ( mkImportedGlobalName, newImportedBinder, mkImportedGlobalFromRdrName,
- lookupOccRn, lookupImplicitOccRn,
- pprAvail,
- availName, availNames, addAvailToNameSet,
- FreeVars, emptyFVs
+import RnHiFiles ( tryLoadInterface, loadHomeInterface,
+ loadOrphanModules
)
+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, elemFM, foldFM
- )
-import Name ( Name {-instance NamedThing-},
- nameModule, isLocallyDefined,
- isWiredInName, nameUnique, NamedThing(..)
+import Id ( idType, idName, globalIdDetails )
+import IdInfo ( GlobalIdDetails(..) )
+import TcType ( namesOfType )
+import FieldLabel ( fieldLabelTyCon )
+import DataCon ( dataConTyCon )
+import TyCon ( visibleDataCons, isSynTyCon, getSynTyConDefn, tyConClass_maybe, tyConName )
+import Class ( className )
+import Name ( Name {-instance NamedThing-}, nameOccName,
+ nameModule, isInternalName, NamedThing(..)
)
-import Module ( Module, moduleString, pprModule,
- mkVanillaModule, pprModuleName,
- moduleUserString, moduleName, isLibModule,
+import NameEnv ( elemNameEnv, delFromNameEnv, lookupNameEnv )
+import NameSet
+import Module ( Module, ModuleEnv,
+ moduleName, isHomeModule,
ModuleName, WhereFrom(..),
+ emptyModuleEnv,
+ extendModuleEnv_C, foldModuleEnv, lookupModuleEnv,
+ elemModuleSet, extendModuleSet
)
-import RdrName ( RdrName, rdrNameOcc )
-import NameSet
-import Var ( Id )
-import SrcLoc ( mkSrcLoc, SrcLoc )
-import PrelMods ( pREL_GHC )
-import PrelInfo ( cCallishTyKeys, thinAirModules )
-import Bag
-import Maybes ( MaybeErr(..), maybeToBool, orElse )
-import ListSetOps ( unionLists )
-import Outputable
-import Unique ( Unique )
-import StringBuffer ( StringBuffer, hGetStringBuffer )
-import FastString ( mkFastString )
-import ErrUtils ( Message )
-import Lex
+import PrelInfo ( wiredInThingEnv, hasKey, fractionalClassKey, numClassKey,
+ integerTyConName, doubleTyConName )
+import Maybe ( isJust )
+import FiniteMap
import Outputable
-
-import IO ( isDoesNotExistError )
-import List ( nub )
+import Bag
+import Util ( sortLt )
\end{code}
%*********************************************************
%* *
-\subsection{Loading a new interface file}
+\subsection{Keeping track of what we've slurped, and version numbers}
%* *
%*********************************************************
-\begin{code}
-loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
-loadHomeInterface doc_str name
- = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem `thenRn` \ (_, ifaces) ->
- returnRn ifaces
-
-loadOrphanModules :: [ModuleName] -> RnM d ()
-loadOrphanModules mods
- | null mods = returnRn ()
- | otherwise = traceRn (text "Loading orphan modules:" <+> fsep (map pprModuleName mods)) `thenRn_`
- mapRn_ load mods `thenRn_`
- returnRn ()
- where
- load mod = loadInterface (pprModuleName mod <+> ptext SLIT("is a orphan-instance module")) mod ImportBySystem
-
-loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Module, Ifaces)
-loadInterface doc_str mod_name from
- = getIfacesRn `thenRn` \ ifaces ->
- let
- mod_map = iImpModInfo ifaces
- mod_info = lookupFM mod_map mod_name
- in_map = maybeToBool mod_info
- in
-
- -- Issue a warning for a redundant {- SOURCE -} import
- -- It's redundant if the moduld is in the iImpModInfo at all,
- -- because we arrange to read all the ordinary imports before
- -- any of the {- SOURCE -} imports
- warnCheckRn (not (in_map && case from of {ImportByUserSource -> True; other -> False}))
- (warnRedundantSourceImport mod_name) `thenRn_`
-
- -- CHECK WHETHER WE HAVE IT ALREADY
- case mod_info of {
- Just (_, _, Just (load_mod, _, _))
- -> -- We're read it already so don't re-read it
- returnRn (load_mod, ifaces) ;
-
- mod_map_result ->
-
- -- READ THE MODULE IN
- findAndReadIface doc_str mod_name from in_map
- `thenRn` \ (hi_boot_read, read_result) ->
- case read_result of {
- Nothing -> -- Not found, so add an empty export env to the Ifaces map
- -- so that we don't look again
- let
- mod = mkVanillaModule mod_name
- new_mod_map = addToFM mod_map mod_name (0, False, Just (mod, False, []))
- new_ifaces = ifaces { iImpModInfo = new_mod_map }
- in
- setIfacesRn new_ifaces `thenRn_`
- failWithRn (mod, new_ifaces) (noIfaceErr mod hi_boot_read) ;
-
- -- Found and parsed!
- Just (mod, iface) ->
-
- -- 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)
-
- getModuleRn `thenRn` \ this_mod_nm ->
- let
- rd_decls = pi_decls iface
- in
- foldlRn (loadDecl mod) (iDecls ifaces) rd_decls `thenRn` \ new_decls ->
- foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
- (if (opt_IgnoreIfacePragmas)
- then returnRn emptyBag
- else foldlRn (loadRule mod) (iRules ifaces) (pi_rules iface)) `thenRn` \ new_rules ->
- foldlRn (loadFixDecl mod_name) (iFixes ifaces) rd_decls `thenRn` \ new_fixities ->
- mapRn (loadExport this_mod_nm) (pi_exports iface) `thenRn` \ avails_s ->
- let
- -- For an explicit user import, add to mod_map info about
- -- the things the imported module depends on, extracted
- -- from its usage info.
- mod_map1 = case from of
- ImportByUser -> addModDeps mod mod_map (pi_usages iface)
- other -> mod_map
-
- -- Now add info about this module
- mod_map2 = addToFM mod_map1 mod_name mod_details
- mod_details = (pi_mod iface, pi_orphan iface, Just (mod, hi_boot_read, concat avails_s))
-
- new_ifaces = ifaces { iImpModInfo = mod_map2,
- iDecls = new_decls,
- iFixes = new_fixities,
- iRules = new_rules,
- iInsts = new_insts }
- in
- setIfacesRn new_ifaces `thenRn_`
- returnRn (mod, new_ifaces)
- }}
+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.
-addModDeps :: Module -> ImportedModuleInfo
- -> [ImportVersion a] -> ImportedModuleInfo
-addModDeps mod mod_deps new_deps
- = foldr add mod_deps new_deps
- where
- is_lib = isLibModule mod -- Don't record dependencies when importing a library module
- add (imp_mod, version, has_orphans, _) deps
- | is_lib && not has_orphans = deps
- | otherwise = addToFM_C combine deps imp_mod (version, has_orphans, Nothing)
- -- Record dependencies for modules that are
- -- either are dependent via a non-library module
- -- or contain orphan rules or instance decls
-
- -- Don't ditch a module that's already loaded!!
- combine old@(_, _, Just _) new = old
- combine old@(_, _, Nothing) new = new
-
-loadExport :: ModuleName -> ExportItem -> RnM d [AvailInfo]
-loadExport this_mod (mod, entities)
- | mod == this_mod = returnRn []
- -- If the module exports anything defined in this module, just ignore it.
- -- Reason: otherwise it looks as if there are two local definition sites
- -- for the thing, and an error gets reported. Easiest thing is just to
- -- filter them out up front. This situation only arises if a module
- -- imports itself, or another module that imported it. (Necessarily,
- -- this invoves a loop.) Consequence: if you say
- -- module A where
- -- import B( AType )
- -- type AType = ...
- --
- -- module B( AType ) where
- -- import {-# SOURCE #-} A( AType )
- --
- -- then you'll get a 'B does not export AType' message. A bit bogus
- -- but it's a bogus thing to do!
+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.
- | otherwise
- = mapRn (load_entity mod) entities
- where
- new_name mod occ = mkImportedGlobalName mod occ
-
- load_entity mod (Avail occ)
- = new_name mod occ `thenRn` \ name ->
- returnRn (Avail name)
- load_entity mod (AvailTC occ occs)
- = new_name mod occ `thenRn` \ name ->
- mapRn (new_name mod) occs `thenRn` \ names ->
- returnRn (AvailTC name names)
-
-
-loadFixDecl :: ModuleName -> FixityEnv
- -> (Version, RdrNameHsDecl)
- -> RnM d FixityEnv
-loadFixDecl mod_name fixity_env (version, FixD sig@(FixitySig rdr_name fixity loc))
- = -- Ignore the version; when the fixity changes the version of
- -- its 'host' entity changes, so we don't need a separate version
- -- number for fixities
- mkImportedGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
- let
- new_fixity_env = addToNameEnv fixity_env name (FixitySig name fixity loc)
- in
- returnRn new_fixity_env
+The usage information records:
- -- Ignore the other sorts of decl
-loadFixDecl mod_name fixity_env other_decl = returnRn fixity_env
+\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}
-loadDecl :: Module
- -> DeclsMap
- -> (Version, RdrNameHsDecl)
- -> RnM d DeclsMap
+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}
-loadDecl mod decls_map (version, decl)
- = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
- case maybe_avail of {
- Nothing -> returnRn decls_map; -- No bindings
- Just avail ->
+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.]
- getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
+\begin{code}
+mkImportInfo :: ModuleName -- Name of this module
+ -> [ImportDecl n] -- The import decls
+ -> RnMG [ImportVersion Name]
+
+mkImportInfo this_mod imports
+ = getIfacesRn `thenRn` \ ifaces ->
+ getHomeIfaceTableRn `thenRn` \ hit ->
let
- main_name = availName avail
- new_decls_map = foldl add_decl decls_map
- [ (name, (version, avail, name==main_name, (mod, decl')))
- | name <- sys_bndrs ++ availNames avail]
- add_decl decls_map (name, stuff)
- = WARN( name `elemNameEnv` decls_map, ppr name )
- addToNameEnv decls_map name stuff
- in
- returnRn new_decls_map
- }
- where
- -- newImportedBinder puts into the cache the binder with the
- -- module information set correctly. When the decl is later renamed,
- -- the binding site will thereby get the correct module.
- new_name rdr_name loc = newImportedBinder mod rdr_name
-
- {-
- If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
- we 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
- its interface file. Hence, B is recompiled, maybe changing its interface file,
- which will the unfolding info used in A to become invalid. Simple way out is to
- just ignore unfolding info.
-
- [Jan 99: I junked the second test above. If we're importing from an hi-boot
- file there isn't going to *be* any pragma info. Maybe the above comment
- dates from a time where we picked up a .hi file first if it existed?]
- -}
- decl' = case decl of
- SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
- -> SigD (IfaceSig name tp [] loc)
- other -> decl
-
-loadInstDecl :: Module
- -> Bag GatedDecl
- -> RdrNameInstDecl
- -> RnM d (Bag GatedDecl)
-loadInstDecl mod 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 spec'd 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 = removeContext inst_ty
- free_names = extractHsTyRdrNames munged_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
- setModuleRn (moduleName mod) $
- mapRn mkImportedGlobalFromRdrName free_names `thenRn` \ gate_names ->
- returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
-
-
--- In interface files, the instance decls now look like
--- forall a. Foo a -> Baz (T a)
--- so we have to strip off function argument types as well
--- as the bit before the '=>' (which is always empty in interface files)
-removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
-removeContext ty = removeFuns ty
-
-removeFuns (MonoFunTy _ ty) = removeFuns ty
-removeFuns ty = ty
-
-
-loadRule :: Module -> Bag GatedDecl
- -> RdrNameRuleDecl -> RnM d (Bag GatedDecl)
--- "Gate" the rule simply by whether the rule variable is
--- needed. We can refine this later.
-loadRule mod rules decl@(IfaceRuleDecl var body src_loc)
- = setModuleRn (moduleName mod) $
- mkImportedGlobalFromRdrName var `thenRn` \ var_name ->
- returnRn ((unitNameSet var_name, (mod, RuleD decl)) `consBag` rules)
+ returnRn import_info
\end{code}
-
-%********************************************************
-%* *
-\subsection{Loading usage information}
-%* *
-%********************************************************
+%*********************************************************
+%* *
+\subsection{Slurping declarations}
+%* *
+%*********************************************************
\begin{code}
-checkUpToDate :: ModuleName -> RnMG Bool -- True <=> no need to recompile
-checkUpToDate mod_name
- = getIfacesRn `thenRn` \ ifaces ->
- findAndReadIface doc_str mod_name
- ImportByUser
- (error "checkUpToDate") `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"),
- pprModuleName mod_name]) `thenRn_`
- returnRn False
-
- Just (_, iface)
- -> -- Found it, so now check it
- checkModUsage (pi_usages iface)
- where
- -- Only look in current directory, with suffix .hi
- doc_str = sep [ptext SLIT("need usage info from"), pprModuleName mod_name]
+-------------------------------------------------------
+slurpImpDecls source_fvs
+ = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
-checkModUsage [] = returnRn True -- Yes! Everything is up to date!
+ -- The current slurped-set records all local things
+ slurpSourceRefs source_fvs `thenRn` \ (decls, needed) ->
-checkModUsage ((mod_name, old_mod_vers, _, whats_imported) : rest)
- = loadInterface doc_str mod_name ImportBySystem `thenRn` \ (mod, ifaces) ->
- let
- maybe_mod_vers = case lookupFM (iImpModInfo ifaces) mod_name of
- Just (version, _, Just (_, _, _)) -> Just version
- other -> Nothing
- in
- case maybe_mod_vers of {
- Nothing -> -- If we can't find a version number for the old module then
- -- bail out saying things aren't up to date
- traceRn (sep [ptext SLIT("Can't find version number for module"),
- pprModuleName mod_name])
- `thenRn_` returnRn False ;
-
- Just new_mod_vers ->
-
- -- 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:"), pprModuleName mod_name])
- `thenRn_` checkModUsage rest
- else
- traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name])
- `thenRn_`
- -- Module version changed, so check entities inside
-
- -- 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 ->
-
- -- Non-empty usage list, so check item by item
- checkEntityUsage mod_name (iDecls ifaces) 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
- }}
- where
- doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name]
+ -- Then get everything else
+ closeDecls decls needed
-checkEntityUsage mod decls []
- = returnRn True -- Yes! All up to date!
+-------------------------------------------------------
+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
-checkEntityUsage mod decls ((occ_name,old_vers) : rest)
- = mkImportedGlobalName mod occ_name `thenRn` \ name ->
- case lookupNameEnv decls name of
+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
+ -- The outer loop repeatedly slurps the decls for the current gates
+ -- and the instance decls
- Nothing -> -- We used it before, but it ain't there now
- traceRn (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
- -> traceRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_`
- returnRn False
+ -- 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}
-%*********************************************************
-%* *
-\subsection{Getting in a declaration}
-%* *
-%*********************************************************
-
\begin{code}
-importDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
- -- Returns Nothing for
- -- (a) wired in name
- -- (b) local decl
- -- (c) already slurped
+-------------------------------------------------------
+-- 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
-importDecl name
- | isWiredInName name
- = returnRn Nothing
| otherwise
- = getSlurped `thenRn` \ already_slurped ->
- if name `elemNameSet` already_slurped then
- returnRn Nothing -- Already dealt with
- else
- if isLocallyDefined name then -- Don't bring in decls from
- -- the renamed module's own interface file
- addWarnRn (importDeclWarn name) `thenRn_`
- returnRn Nothing
- else
- getNonWiredInDecl name
+ = 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}
+
\begin{code}
-getNonWiredInDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
-getNonWiredInDecl needed_name
- = traceRn doc_str `thenRn_`
- loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
- case lookupNameEnv (iDecls ifaces) needed_name of
-
- Just (version,avail,_,decl)
- -> recordSlurp (Just version) avail `thenRn_`
- returnRn (Just decl)
-
- Nothing -- Can happen legitimately for "Optional" occurrences
- -> addErrRn (getDeclErr needed_name) `thenRn_`
- returnRn Nothing
+recordDeclSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped),
+ iSlurp = slurped_names,
+ iVSlurp = vslurp })
+ avail
+ = ASSERT2( not (isInternalName (availName avail)), ppr avail )
+ ifaces { iDecls = (new_decls_map, n_slurped+1),
+ iSlurp = new_slurped_names,
+ iVSlurp = updateVSlurp vslurp (availName avail) }
where
- doc_str = ptext SLIT("need decl for") <+> ppr needed_name
-\end{code}
+ new_decls_map = foldl delFromNameEnv decls_map (availNames avail)
+ new_slurped_names = addAvailToNameSet slurped_names avail
-@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,
-\begin{itemize}
-\item 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.
-\item similarly for synonum type constructor
+-- 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
-\item if the wired-in name is another wired-in Id, it marks as ``occurrences''
- the free vars of the Id's type.
+recordTypeEnvSlurp ifaces ty_thing
+ = ifaces { iVSlurp = updateVSlurp (iVSlurp ifaces) (get_main_name ty_thing) }
+ where
+ -- 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}
-\item it loads the interface file for the wired-in thing for the
- sole purpose of making sure that its instance declarations are available
-\end{itemize}
-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.
-
-
%*********************************************************
-%* *
-\subsection{Getting what a module exports}
-%* *
+%* *
+\subsection{Extracting the `gates'}
+%* *
%*********************************************************
-@getInterfaceExports@ is called only for directly-imported modules.
+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.
+
+ instance (..) => C (T1 a) (T2 b) where ...
+
+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.
+
+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
+
+ all its gates are either in the gates of the module,
+ or are a previously-loaded tycon or class.
+
+The latter constraint is because there might have been an instance
+decl slurped in during an earlier compilation, like this:
+
+ instance Foo a => Baz (Maybe a) where ...
+
+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. More generally, types
+might be involved as well:
+
+ instance Foo2 T a => Baz2 a where ...
+
+Now we must treat T as a gate too, as well as Foo. So the solution
+we adopt is:
+
+ we simply treat all previously-loaded
+ tycons and classes as gates.
+
+This gloss only affects ghc --make and ghc --interactive.
+
+
+Consructors and class operations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When we import a declaration like
+
+ data T = T1 Wibble | T2 Wobble
+
+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.
+
+-----------------------------
+@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}
-getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
-getInterfaceExports mod_name from
- = loadInterface doc_str mod_name from `thenRn` \ (mod, ifaces) ->
- case lookupFM (iImpModInfo ifaces) mod_name 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 (mod, [])
-
- Just (_, _, Just (mod, _, avails)) -> returnRn (mod, avails)
+getGates :: FreeVars -- Things mentioned in the source program
+ -- Used for the cunning "constructors and
+ -- class ops" story described 10 lines above.
+ -> RenamedTyClDecl
+ -> FreeVars
+
+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 (CoreDecl {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)
+ (visibleDataCons cons))
+ (hsTyVarNames tvs)
+ `addOneToNameSet` tycon
where
- doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")]
+ 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}
+@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded
+thing rather than a declaration.
-%*********************************************************
-%* *
-\subsection{Instance declarations are handled specially}
-%* *
-%*********************************************************
+\begin{code}
+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
+ (tyvars,ty) = getSynTyConDefn tc
+
+getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty
+\end{code}
\begin{code}
-getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
+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, Nothing)) <- fmToList (iImpModInfo ifaces)]
+ [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)]
in
loadOrphanModules orphan_mods `thenRn_`
-- Find the un-gated ones and return them,
-- removing them from the bag kept in Ifaces
getIfacesRn `thenRn` \ ifaces ->
+ getTypeEnvRn `thenRn` \ lookup ->
let
- (decls, new_insts) = selectGated gates (iInsts ifaces)
+ available n = n `elemNameSet` gates || isJust (lookup n)
+ -- See "The gating story" above for the isJust thing
+
+ (decls, new_insts) = selectGated available (iInsts ifaces)
in
setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
where
gate_list = nameSetToList gates
- load_home gate | isLocallyDefined gate
- = returnRn ()
- | otherwise
- = loadHomeInterface (ppr gate <+> text "is an instance gate") gate `thenRn_`
- returnRn ()
-
-ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
+ppr_brief_inst_decl (mod, InstDecl inst_ty _ _ _ _)
= case inst_ty of
HsForAllTy _ _ tau -> ppr tau
other -> ppr inst_ty
-getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
+getImportedRules :: RnMG [(Module,RdrNameRuleDecl)]
getImportedRules
| opt_IgnoreIfacePragmas = returnRn []
| otherwise
= getIfacesRn `thenRn` \ ifaces ->
+ getTypeEnvRn `thenRn` \ lookup ->
let
- gates = iSlurp ifaces -- Anything at all that's been slurped
- (decls, new_rules) = selectGated gates (iRules ifaces)
+ -- Slurp rules for anything that is slurped,
+ -- either now or previously
+ gates = iSlurp ifaces
+ available n = n `elemNameSet` gates || isJust (lookup n)
+ (decls, new_rules) = selectGated available (iRules ifaces)
in
- setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
+ if null decls then
+ returnRn []
+ else
+ setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
traceRn (sep [text "getImportedRules:",
- text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
+ text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
returnRn decls
-selectGated gates decl_bag
- -- Select only those decls whose gates are *all* in 'gates'
+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
- = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
+ = let
+ decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all
+ in
+ (decls, (emptyBag, n_slurped + length decls))
| otherwise
#endif
- = foldrBag select ([], emptyBag) decl_bag
+ = case foldrBag select ([], emptyBag) decl_bag of
+ (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls))
where
- select (reqd, decl) (yes, no)
- | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
- | otherwise = (yes, (reqd,decl) `consBag` no)
-
-lookupFixity :: Name -> RnMS Fixity
-lookupFixity name
- | isLocallyDefined name
- = getFixityEnv `thenRn` \ local_fix_env ->
- case lookupNameEnv local_fix_env name of
- Just (FixitySig _ fix _) -> returnRn fix
- Nothing -> returnRn defaultFixity
-
- | otherwise -- Imported
- = loadHomeInterface doc name `thenRn` \ ifaces ->
- case lookupNameEnv (iFixes ifaces) name of
- Just (FixitySig _ fix _) -> returnRn fix
- Nothing -> returnRn defaultFixity
- where
- doc = ptext SLIT("Checking fixity for") <+> ppr name
+ select (gate_fn, decl) (yes, no)
+ | gate_fn available = (decl:yes, no)
+ | otherwise = (yes, (gate_fn,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:
-\begin{itemize}
-\item anything reachable from its body code
-\item any module exported with a @module Foo@.
-\end{itemize}
-%
-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.
+\begin{code}
+importDecl :: Name -> RnMG ImportDeclResult
-What about this?
-\begin{verbatim}
- module A( f, g ) where | module B( f ) where
- import B( f ) | f = h 3
- g = ... | h = ...
-\end{verbatim}
-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{enumerate}
-\item Are @A.o@ and @A.hi@ correct? Then we can bale out early.
-\item Should modules that import @A@ be recompiled?
-\end{enumerate}
-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@
-(and this usage-version info isn't used by any importer).
-
-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.
-
-On the other hand, if @A@ exports @module B@,
-then we {\em do} count @module B@ among @A@'s usages,
-because we must recompile @A@ to ensure that @A.hi@ changes appropriately.
+data ImportDeclResult
+ = AlreadySlurped
+ | InTypeEnv TyThing
+ | HereItIs (Module, RdrNameTyClDecl)
-\begin{code}
-getImportVersions :: ModuleName -- Name of this module
- -> Maybe [IE any] -- Export list for this module
- -> RnMG (VersionInfo Name) -- Version info for these names
+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
-getImportVersions this_mod exports
- = getIfacesRn `thenRn` \ ifaces ->
- let
- mod_map = iImpModInfo ifaces
- imp_names = iVSlurp ifaces
-
- -- mv_map groups together all the things imported from a particular module.
- mv_map1, mv_map2 :: FiniteMap ModuleName (WhatsImported Name)
-
- -- mv_map1 records all the modules that have a "module M"
- -- in this module's export list with an "Everything"
- mv_map1 = foldr add_mod emptyFM export_mods
-
- -- mv_map2 adds the version numbers of things exported individually
- mv_map2 = foldr add_mv mv_map1 imp_names
-
- -- Build the result list by adding info for each module.
- -- For (a) library modules
- -- (b) source-imported modules
- -- we do something special. We don't want to record detailed usage information.
- -- Indeed we don't want to record them at all unless they contain orphans,
- -- which we must never lose track of.
- mk_version_info mod_name (version, has_orphans, cts) so_far
- | lib_or_source_imported && not has_orphans
- = so_far -- Don't record any usage info for this module
-
- | lib_or_source_imported -- Has orphans; record the module but not
- -- detailed version information for the imports
- = (mod_name, version, has_orphans, Specifically []) : so_far
-
- | otherwise
- = (mod_name, version, has_orphans, whats_imported) : so_far
- where
- whats_imported = case lookupFM mv_map2 mod_name of
- Just wi -> wi
- Nothing -> Specifically []
-
- lib_or_source_imported = case cts of
- Just (mod, boot_import, _) -> isLibModule mod || boot_import
- Nothing -> False
- in
- returnRn (foldFM mk_version_info [] mod_map)
- where
- export_mods = case exports of
- Nothing -> []
- Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod]
- add_mv v@(name, version) mv_map
- = addToFM_C add_item mv_map mod (Specifically [v])
- where
- mod = moduleName (nameModule name)
+ -- 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)
- add_item Everything _ = Everything
- add_item (Specifically xs) _ = Specifically (v:xs)
+ | otherwise
+ -> -- Very important: record that we've seen it
+ -- See comments with recordTypeEnvSlurp
+ setIfacesRn (recordTypeEnvSlurp ifaces ty_thing) `thenRn_`
+ returnRn (InTypeEnv ty_thing) ;
- add_mod mod mv_map = addToFM mv_map mod Everything
-\end{code}
+ Nothing ->
-\begin{code}
-getSlurped
- = getIfacesRn `thenRn` \ ifaces ->
- returnRn (iSlurp ifaces)
+ -- 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 ->
-recordSlurp maybe_version avail
- = getIfacesRn `thenRn` \ ifaces@(Ifaces { iSlurp = slurped_names,
- iVSlurp = imp_names }) ->
+ -- STEP 4: Get the declaration out
let
- new_slurped_names = addAvailToNameSet slurped_names avail
-
- new_imp_names = case maybe_version of
- Just version -> (availName avail, version) : imp_names
- Nothing -> imp_names
+ (decls_map, _) = iDecls ifaces
in
- setIfacesRn (ifaces { iSlurp = new_slurped_names,
- iVSlurp = new_imp_names })
+ 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
+ wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name
+ nd_doc = ptext SLIT("need decl for") <+> ppr name
+
\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 -> RnM d Name) -- New-name function
- -> RdrNameHsDecl
- -> RnM d (Maybe AvailInfo)
-
-getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ src_loc))
- = new_name tycon src_loc `thenRn` \ tycon_name ->
- getConFieldNames new_name condecls `thenRn` \ sub_names ->
- returnRn (Just (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 (TyClD (TySynonym tycon _ _ src_loc))
- = new_name tycon src_loc `thenRn` \ tycon_name ->
- returnRn (Just (AvailTC tycon_name [tycon_name]))
-
-getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ src_loc))
- = new_name cname src_loc `thenRn` \ class_name ->
-
- -- Record the names for the class ops
+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
- -- just want class-op sigs
- op_sigs = filter isClassOpSig sigs
+ doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
+ from | is_boot = ImportByUserSource
+ | otherwise = ImportByUser
in
- mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
-
- returnRn (Just (AvailTC class_name (class_name : sub_names)))
+ traceHiDiffsRn (text "Checking usages for module" <+> ppr mod_name) `thenRn_`
+ tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) ->
-getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
- = new_name var src_loc `thenRn` \ var_name ->
- returnRn (Just (Avail var_name))
+ 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
-getDeclBinders new_name (FixD _) = returnRn Nothing
+ Nothing ->
+ let
+ new_vers = mi_version iface
+ new_decl_vers = vers_decls new_vers
+ in
+ case whats_imported of { -- NothingAtAll dealt with earlier
- -- foreign declarations
-getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
- | binds_haskell_name kind dyn
- = new_name nm loc `thenRn` \ name ->
- returnRn (Just (Avail name))
+ 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 ;
- | otherwise -- a foreign export
- = lookupImplicitOccRn nm `thenRn_`
- returnRn Nothing
+ Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers ->
-getDeclBinders new_name (DefD _) = returnRn Nothing
-getDeclBinders new_name (InstD _) = returnRn Nothing
-getDeclBinders new_name (RuleD _) = returnRn Nothing
+ -- 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
-binds_haskell_name (FoImport _) _ = True
-binds_haskell_name FoLabel _ = True
-binds_haskell_name FoExport ext_nm = isDynamic ext_nm
+ -- CHECK RULES
+ if old_rule_vers /= vers_rules new_vers then
+ out_of_date (ptext SLIT("Rules changed"))
+ else
-----------------
-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 _ _ condecl src_loc : rest)
- = new_name con src_loc `thenRn` \ n ->
- (case condecl of
- NewCon _ (Just f) ->
- new_name f src_loc `thenRn` \ new_f ->
- returnRn [n,new_f]
- _ -> returnRn [n]) `thenRn` \ nn ->
- getConFieldNames new_name rest `thenRn` \ ns ->
- returnRn (nn ++ 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"))
-@getDeclSysBinders@ gets the implicit binders introduced by a decl.
-A the moment that's just the tycon and datacon that come with a class decl.
-They aren't returned by @getDeclBinders@ because they aren't in scope;
-but they {\em should} be put into the @DeclsMap@ of this module.
+------------------------
+checkExportList Nothing new_vers = upToDate
+checkExportList (Just v) new_vers = v /= vers_exports new_vers
-Note that this excludes the default-method names of a class decl,
-and the dict fun of an instance decl, because both of these have
-bindings of their own elsewhere.
+------------------------
+checkEntityUsage new_vers (name,old_vers)
+ = case lookupNameEnv new_vers name of
-\begin{code}
-getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname snames src_loc))
- = new_name dname src_loc `thenRn` \ datacon_name ->
- new_name tname src_loc `thenRn` \ tycon_name ->
- sequenceRn [new_name n src_loc | n <- snames] `thenRn` \ scsel_names ->
- returnRn (tycon_name : datacon_name : scsel_names)
-
-getDeclSysBinders new_name other_decl
- = returnRn []
-\end{code}
+ Nothing -> -- We used it before, but it ain't there now
+ out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
-%*********************************************************
-%* *
-\subsection{Reading an interface file}
-%* *
-%*********************************************************
+ 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])
-\begin{code}
-findAndReadIface :: SDoc -> ModuleName -> WhereFrom
- -> Bool -- Only relevant for SystemImport
- -- True <=> Look for a .hi file
- -- False <=> Look for .hi-boot file unless there's
- -- a library .hi file
- -> RnM d (Bool, Maybe (Module, ParsedIface))
- -- Bool is True if the interface actually read was a .hi-boot one
- -- Nothing <=> file not found, or unreadable, or illegible
- -- Just x <=> successfully found and parsed
-
-findAndReadIface doc_str mod_name from hi_file
- = traceRn trace_msg `thenRn_`
- -- we keep two maps for interface files,
- -- one for 'normal' ones, the other for .hi-boot files,
- -- hence the need to signal which kind we're interested.
-
- getHiMaps `thenRn` \ hi_maps ->
-
- case find_path from hi_maps of
- -- Found the file
- (hi_boot, Just (fpath, mod)) -> traceRn (ptext SLIT("...reading from") <+> text fpath)
- `thenRn_`
- readIface mod fpath `thenRn` \ result ->
- returnRn (hi_boot, result)
- (hi_boot, Nothing) -> traceRn (ptext SLIT("...not found")) `thenRn_`
- returnRn (hi_boot, Nothing)
- where
- find_path ImportByUser (hi_map, _) = (False, lookupFM hi_map mod_name)
- find_path ImportByUserSource (_, hiboot_map) = (True, lookupFM hiboot_map mod_name)
-
- find_path ImportBySystem (hi_map, hiboot_map)
- | hi_file
- = -- If the module we seek is in our dependent set,
- -- Look for a .hi file
- (False, lookupFM hi_map mod_name)
-
- | otherwise
- -- Check if there's a library module of that name
- -- If not, look for an hi-boot file
- = case lookupFM hi_map mod_name of
- stuff@(Just (_, mod)) | isLibModule mod -> (False, stuff)
- other -> (True, lookupFM hiboot_map mod_name)
-
- trace_msg = sep [hsep [ptext SLIT("Reading"),
- ppr from,
- ptext SLIT("interface for"),
- pprModuleName mod_name <> semi],
- nest 4 (ptext SLIT("reason:") <+> doc_str)]
+up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate
+out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate
\end{code}
-@readIface@ tries just the one file.
-
-\begin{code}
-readIface :: Module -> String -> RnM d (Maybe (Module, ParsedIface))
- -- Nothing <=> file not found, or unreadable, or illegible
- -- Just x <=> successfully found and parsed
-readIface the_mod file_path
- = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
- case read_result of
- Right contents ->
- case parseIface contents
- PState{ bol = 0#, atbol = 1#,
- context = [],
- glasgow_exts = 1#,
- loc = mkSrcLoc (mkFastString file_path) 1 } of
- PFailed err -> failWithRn Nothing err
- POk _ (PIface mod_nm iface) ->
- warnCheckRn (mod_nm == moduleName the_mod)
- (hiModuleNameMismatchWarn the_mod mod_nm) `thenRn_`
- returnRn (Just (the_mod, iface))
-
- Left err
- | isDoesNotExistError err -> returnRn Nothing
- | otherwise -> failWithRn Nothing (cannaeReadFile file_path err)
-\end{code}
%*********************************************************
%* *
%*********************************************************
\begin{code}
-noIfaceErr filename boot_file
- = hsep [ptext SLIT("Could not find valid"), boot,
- ptext SLIT("interface file"), quotes (pprModule filename)]
- where
- boot | boot_file = ptext SLIT("[boot]")
- | otherwise = empty
-
-cannaeReadFile file err
- = hcat [ptext SLIT("Failed in reading file: "),
- text file,
- ptext SLIT("; error="),
- text (show err)]
-
getDeclErr name
- = ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name)
-
-getDeclWarn name loc
- = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name),
- ptext SLIT("desired at") <+> ppr loc]
-
-importDeclWarn name
- = sep [ptext SLIT(
- "Compiler tried to import decl from interface file with same name as module."),
- ptext SLIT(
- "(possible cause: module name clashes with interface file already in scope.)")
- ] $$
- hsep [ptext SLIT("name:"), quotes (ppr name)]
-
-warnRedundantSourceImport mod_name
- = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
- <+> quotes (pprModuleName mod_name)
-
-hiModuleNameMismatchWarn :: Module -> ModuleName -> Message
-hiModuleNameMismatchWarn requested_mod mod_nm =
- hsep [ ptext SLIT("Something is amiss; requested module name")
- , pprModule requested_mod
- , ptext SLIT("differs from name found in the interface file ")
- , pprModuleName mod_nm
- ]
-
+ = 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