%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnIfaces]{Cacheing and Renaming of Interfaces}
\begin{code}
+module RnIfaces
+ (
+ getInterfaceExports,
+ recordLocalSlurps,
+ mkImportInfo,
+
+ slurpImpDecls, closeDecls,
+
+ RecompileRequired, outOfDate, upToDate, recompileRequired
+ )
+where
+
#include "HsVersions.h"
-module RnIfaces (
- findHiFiles,
- cachedIface,
- readIface,
- rnIfaces,
- finalIfaceInfo,
- IfaceCache(..),
- VersionInfo(..)
- ) where
-
-import Ubiq
-
-import LibDirectory
-import PreludeGlaST ( returnPrimIO, thenPrimIO, seqPrimIO,
- readVar, writeVar, MutableVar(..)
+import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls )
+import HscTypes
+import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..),
+ InstDecl(..), HsType(..), hsTyVarNames, getBangType
+ )
+import HsImpExp ( ImportDecl(..) )
+import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl, RdrNameInstDecl )
+import RnHsSyn ( RenamedHsDecl, extractHsTyNames, extractHsCtxtTyNames, tyClDeclFVs )
+import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface,
+ loadOrphanModules
+ )
+import RnSource ( rnTyClDecl, rnDecl )
+import RnEnv
+import RnMonad
+import Id ( idType )
+import Type ( namesOfType )
+import TyCon ( isSynTyCon, getSynTyConDefn )
+import Name ( Name {-instance NamedThing-}, nameOccName,
+ nameModule, isLocallyDefined, nameUnique,
+ NamedThing(..),
+ elemNameEnv
+ )
+import Module ( Module, ModuleEnv,
+ moduleName, isModuleInThisPackage,
+ ModuleName, WhereFrom(..),
+ emptyModuleEnv,
+ extendModuleEnv_C, foldModuleEnv, lookupModuleEnv,
+ elemModuleSet, extendModuleSet
)
+import NameSet
+import PrelInfo ( wiredInThingEnv, fractionalClassKeys )
+import TysWiredIn ( doubleTyCon )
+import Maybes ( orElse )
+import FiniteMap
+import Outputable
+import Bag
+import Util ( sortLt )
+\end{code}
-import HsSyn
-import RdrHsSyn
-import RnHsSyn
-import RnMonad
-import RnUtils ( RnEnv(..) )
-import ParseIface ( parseIface, ParsedIface )
-
-import Bag ( emptyBag )
-import CmdLineOpts ( opt_HiSuffix, opt_SysHiSuffix )
-import ErrUtils ( Error(..), Warning(..) )
-import FiniteMap ( emptyFM, lookupFM, addToFM )
-import Pretty
-import Maybes ( MaybeErr(..) )
-import Util ( startsWith, panic )
+%*********************************************************
+%* *
+\subsection{Getting what a module exports}
+%* *
+%*********************************************************
+
+@getInterfaceExports@ is called only for directly-imported modules.
+
+\begin{code}
+getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)])
+getInterfaceExports mod_name from
+ = loadInterface doc_str mod_name from `thenRn` \ iface ->
+ returnRn (mi_module iface, mi_exports iface)
+ where
+ doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Instance declarations are handled specially}
+%* *
+%*********************************************************
+
+\begin{code}
+getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
+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 ->
+ let
+ (decls, new_insts) = selectGated gates (iInsts ifaces)
+ in
+ 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
+ gate_list = nameSetToList gates
+
+ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
+ = case inst_ty of
+ HsForAllTy _ _ tau -> ppr tau
+ other -> ppr inst_ty
+
+getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
+getImportedRules
+ | opt_IgnoreIfacePragmas = returnRn []
+ | otherwise
+ = getIfacesRn `thenRn` \ ifaces ->
+ let
+ gates = iSlurp ifaces -- Anything at all that's been slurped
+ rules = iRules ifaces
+ (decls, new_rules) = selectGated gates rules
+ in
+ if null decls then
+ returnRn []
+ else
+ setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
+ traceRn (sep [text "getImportedRules:",
+ text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
+ returnRn decls
+
+selectGated gates decl_bag
+ -- Select only those decls whose gates are *all* in 'gates'
+#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
+
+ | otherwise
+#endif
+ = foldrBag select ([], emptyBag) decl_bag
+ where
+ select (reqd, decl) (yes, no)
+ | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
+ | otherwise = (yes, (reqd,decl) `consBag` no)
\end{code}
+
+%*********************************************************
+%* *
+\subsection{Keeping track of what we've slurped, and version numbers}
+%* *
+%*********************************************************
+
+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 (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.
+
+[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.]
+
+Even if B is used at all we get a usage line for B
+ import B <n> :: ... ;
+in A.hi, to record the fact that A does import B. This is used to decide
+to look to look for B.hi rather than B.hi-boot when compiling a module that
+imports A. This line says that A imports B, but uses nothing in it.
+So we'll get an early bale-out when compiling A if B's version changes.
+
\begin{code}
-type ModuleToIfaceContents = FiniteMap Module ParsedIface
-type ModuleToIfaceFilePath = FiniteMap Module FilePath
+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
+ (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
-type IfaceCache
- = MutableVar _RealWorld (ModuleToIfaceContents,
- ModuleToIfaceFilePath)
+ -- 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
+ --
+ -- d) NothingAtAll: The name only of all orphan modules we know of (this is needed
+ -- so that anyone who imports us can find the orphan modules)
+ -- These modules are in a combination of HIT/PIT and iImpModInfo
+
+ import_info0 = foldModuleEnv mk_imp_info [] pit
+ import_info1 = foldModuleEnv mk_imp_info import_info0 hit
+ import_info = [ (mod_name, orphans, is_boot, NothingAtAll)
+ | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ] ++
+ import_info1
+
+ mk_imp_info :: ModIface -> [ImportVersion Name] -> [ImportVersion Name]
+ mk_imp_info iface so_far
+
+ | Just ns <- lookupModuleEnv mv_map mod -- Case (a)
+ = go_for_it (Specifically mod_vers maybe_export_vers
+ (mk_import_items ns) rules_vers)
+
+ | mod `elemModuleSet` imp_pkg_mods -- Case (b)
+ = go_for_it (Everything mod_vers)
+
+ | import_all_mod -- Case (a) and (b); the import-all part
+ = if is_home_pkg_mod then
+ go_for_it (Specifically mod_vers (Just export_vers) [] rules_vers)
+ else
+ go_for_it (Everything mod_vers)
+
+ | is_home_pkg_mod || has_orphans -- Case (c) or (d)
+ = go_for_it NothingAtAll
+
+ | otherwise = so_far
+ where
+ go_for_it exports = (mod_name, has_orphans, mi_boot iface, exports) : so_far
+
+ mod = mi_module iface
+ mod_name = moduleName mod
+ is_home_pkg_mod = isModuleInThisPackage mod
+ version_info = mi_version iface
+ version_env = vers_decls version_info
+ mod_vers = vers_module version_info
+ rules_vers = vers_rules version_info
+ export_vers = vers_exports version_info
+ import_all_mod = mod_name `elem` import_all_mods
+ has_orphans = mi_orphan iface
+
+ -- The sort is to put them into canonical order
+ mk_import_items ns = [(n,v) | n <- sortLt lt_occ ns,
+ let v = lookupNameEnv version_env n `orElse`
+ pprPanic "mk_whats_imported" (ppr n)
+ ]
+ where
+ lt_occ n1 n2 = nameOccName n1 < nameOccName n2
+
+ maybe_export_vers | import_all_mod = Just (vers_exports version_info)
+ | otherwise = Nothing
+ in
+ returnRn import_info
\end{code}
-*********************************************************
-* *
-\subsection{Looking for interface files}
-* *
-*********************************************************
+%*********************************************************
+%* *
+\subsection{Slurping declarations}
+%* *
+%*********************************************************
-Return a mapping from module-name to
-absolute-filename-for-that-interface.
\begin{code}
-findHiFiles :: [FilePath] -> [FilePath] -> IO (FiniteMap Module FilePath)
+-------------------------------------------------------
+slurpImpDecls source_fvs
+ = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
+
+ -- The current slurped-set records all local things
+ getSlurped `thenRn` \ source_binders ->
+ slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) ->
+
+ -- Then get everything else
+ closeDecls decls needed `thenRn` \ decls1 ->
+
+ -- Finally, get any deferred data type decls
+ slurpDeferredDecls decls1 `thenRn` \ final_decls ->
-findHiFiles dirs sysdirs
- = do_dirs emptyFM (dirs ++ sysdirs)
+ returnRn final_decls
+
+
+-------------------------------------------------------
+slurpSourceRefs :: NameSet -- Variables defined in source
+ -> FreeVars -- Variables referenced in source
+ -> RnMG ([RenamedHsDecl],
+ FreeVars) -- Un-satisfied needs
+-- The declaration (and hence home module) of each gate has
+-- already been loaded
+
+slurpSourceRefs source_binders source_fvs
+ = go_outer [] -- Accumulating decls
+ emptyFVs -- Unsatisfied needs
+ emptyFVs -- Accumulating gates
+ (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
where
- do_dirs env [] = return env
- do_dirs env (dir:dirs)
- = do_dir env dir >>= \ new_env ->
- do_dirs new_env dirs
- -------
- do_dir env dir
- = --trace ("Having a go on..."++dir) $
- getDirectoryContents dir >>= \ entries ->
- do_entries env entries
- -------
- do_entries env [] = return env
- do_entries env (e:es)
- = do_entry env e >>= \ new_env ->
- do_entries new_env es
- -------
- do_entry env e
- = case (acceptable_hi (reverse e)) of
- Nothing -> --trace ("Deemed uncool:"++e) $
- return env
- Just mod -> let
- pmod = _PK_ mod
- in
- case (lookupFM env pmod) of
- Nothing -> --trace ("Adding "++mod++" -> "++e) $
- return (addToFM env pmod e)
- Just xx -> trace ("Already mapped: "++mod++" -> "++xx) $
- return env
- -------
- acceptable_hi rev_e -- looking at pathname *backwards*
- = case (startsWith (reverse opt_HiSuffix) rev_e) of
- Nothing -> Nothing
- Just xs -> plausible_modname xs{-reversed-}
-
- -------
- plausible_modname rev_e
- = let
- cand = reverse (takeWhile is_modname_char rev_e)
- in
- if null cand || not (isUpper (head cand))
- then Nothing
- else Just cand
- where
- is_modname_char c = isAlphanum c || c == '_'
+ -- 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 ->
+ rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
+ go_outer decls2 fvs2 (all_gates `plusFV` gates2)
+ (nameSetToList (gates2 `minusNameSet` all_gates))
+ -- Knock out the all_gates because even if we don't slurp any new
+ -- decls we can get some apparently-new gates from wired-in names
+
+ go_inner (decls, fvs, gates) wanted_name
+ = importDecl wanted_name `thenRn` \ import_result ->
+ case import_result of
+ AlreadySlurped -> returnRn (decls, fvs, gates)
+ WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name)
+ Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor
+
+ HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (TyClD new_decl : decls,
+ fvs1 `plusFV` fvs,
+ gates `plusFV` getGates source_fvs new_decl)
+
+rnInstDecls decls fvs gates []
+ = returnRn (decls, fvs, gates)
+rnInstDecls decls fvs gates (d:ds)
+ = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnInstDecls (new_decl:decls)
+ (fvs1 `plusFV` fvs)
+ (gates `plusFV` getInstDeclGates new_decl)
+ ds
\end{code}
-*********************************************************
-* *
-\subsection{Reading interface files}
-* *
-*********************************************************
-Return cached info about a Module's interface; otherwise,
-read the interface (using our @ModuleToIfaceFilePath@ map
-to decide where to look).
+\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 decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) ->
+ closeDecls decls1 needed1
+
+
+-------------------------------------------------------
+-- 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 :: [RenamedHsDecl] -> FreeVars
+ -> [(Module, RdrNameHsDecl)]
+ -> RnM d ([RenamedHsDecl], FreeVars)
+rnIfaceDecls decls fvs [] = returnRn (decls, fvs)
+rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds
+
+rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl)
+rnIfaceTyClDecl (mod, decl) = initIfaceRnMS mod (rnTyClDecl decl) `thenRn` \ decl' ->
+ returnRn (decl', tyClDeclFVs decl')
+\end{code}
+
\begin{code}
-cachedIface :: IfaceCache
- -> Module
- -> IO (MaybeErr ParsedIface Error)
-
-cachedIface iface_var mod
- = readVar iface_var `thenPrimIO` \ (iface_fm, file_fm) ->
-
- case (lookupFM iface_fm mod) of
- Just iface -> return (Succeeded iface)
- Nothing ->
- case (lookupFM file_fm mod) of
- Nothing -> return (Failed (noIfaceErr mod))
- Just file ->
- readIface file mod >>= \ read_iface ->
- case read_iface of
- Failed err -> return (Failed err)
- Succeeded iface ->
- let
- iface_fm' = addToFM iface_fm mod iface
- in
- writeVar iface_var (iface_fm', file_fm) `seqPrimIO`
- return (Succeeded iface)
+getSlurped
+ = getIfacesRn `thenRn` \ ifaces ->
+ returnRn (iSlurp ifaces)
+
+recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = (imp_mods, imp_names) })
+ avail
+ = let
+ new_slurped_names = addAvailToNameSet slurped_names avail
+ new_vslurp | isModuleInThisPackage mod = (imp_mods, addOneToNameSet imp_names name)
+ | otherwise = (extendModuleSet imp_mods mod, imp_names)
+ where
+ mod = nameModule name
+ name = availName avail
+ in
+ ifaces { iSlurp = new_slurped_names, iVSlurp = new_vslurp }
+
+recordLocalSlurps local_avails
+ = getIfacesRn `thenRn` \ ifaces ->
+ let
+ new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
+ in
+ setIfacesRn (ifaces { iSlurp = new_slurped_names })
\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Deferred declarations}
+%* *
+%*********************************************************
+
+The idea of deferred declarations is this. Suppose we have a function
+ f :: T -> Int
+ data T = T1 A | T2 B
+ data A = A1 X | A2 Y
+ data B = B1 P | B2 Q
+Then we don't want to load T and all its constructors, and all
+the types those constructors refer to, and all the types *those*
+constructors refer to, and so on. That might mean loading many more
+interface files than is really necessary. So we 'defer' loading T.
+
+But f might be strict, and the calling convention for evaluating
+values of type T depends on how many constructors T has, so
+we do need to load T, but not the full details of the type T.
+So we load the full decl for T, but only skeleton decls for A and B:
+ f :: T -> Int
+ data T = {- 2 constructors -}
+
+Whether all this is worth it is moot.
+
\begin{code}
-readIface :: FilePath -> Module
- -> IO (MaybeErr ParsedIface Error)
-
-readIface file mod
- = readFile file `thenPrimIO` \ read_result ->
- case read_result of
- Left err -> return (Failed (cannaeReadErr file))
- Right contents -> return (Succeeded (parseIface contents))
+slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
+slurpDeferredDecls decls = returnRn decls
+
+{- OMIT FOR NOW
+slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
+slurpDeferredDecls decls
+ = getDeferredDecls `thenRn` \ def_decls ->
+ rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) ->
+ ASSERT( isEmptyFVs fvs )
+ returnRn decls1
+
+stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ loc name1 name2))
+ = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing loc
+ name1 name2))
+ -- Nuke the context and constructors
+ -- But retain the *number* of constructors!
+ -- Also the tvs will have kinds on them.
+-}
\end{code}
+%*********************************************************
+%* *
+\subsection{Extracting the `gates'}
+%* *
+%*********************************************************
+
+When we import a declaration like
+\begin{verbatim}
+ data T = T1 Wibble | T2 Wobble
+\end{verbatim}
+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.
+
+@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}
-rnIfaces :: IfaceCache -- iface cache
- -> RnEnv -- original name env
- -> UniqSupply
- -> RenamedHsModule -- module to extend with iface decls
- -> [RnName] -- imported names required
- -> PrimIO (RenamedHsModule, -- extended module
- ImplicitEnv, -- implicit names required
- Bag Error,
- Bag Warning)
-
-rnIfaces iface_var occ_env us rn_module todo
- = returnPrimIO (rn_module, (emptyFM, emptyFM), emptyBag, emptyBag)
+getGates source_fvs (IfaceSig _ ty _ _)
+ = extractHsTyNames ty
+
+getGates source_fvs (ClassDecl ctxt cls tvs _ sigs _ _ _ )
+ = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
+ (hsTyVarNames tvs)
+ `addOneToNameSet` cls)
+ `plusFV` maybe_double
+ where
+ get (ClassOpSig n _ ty _)
+ | n `elemNameSet` source_fvs = extractHsTyNames ty
+ | otherwise = emptyFVs
+
+ -- If we load any numeric class that doesn't have
+ -- Int as an instance, add Double to the gates.
+ -- This takes account of the fact that Double might be needed for
+ -- defaulting, but we don't want to load Double (and all its baggage)
+ -- if the more exotic classes aren't used at all.
+ maybe_double | nameUnique cls `elem` fractionalClassKeys
+ = unitFV (getName doubleTyCon)
+ | otherwise
+ = emptyFVs
+
+getGates source_fvs (TySynonym tycon tvs ty _)
+ = delListFromNameSet (extractHsTyNames ty)
+ (hsTyVarNames tvs)
+ -- A type synonym type constructor isn't a "gate" for instance decls
+
+getGates source_fvs (TyData _ ctxt tycon tvs cons _ _ _ _ _)
+ = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
+ (hsTyVarNames tvs)
+ `addOneToNameSet` tycon
+ where
+ get (ConDecl n _ tvs ctxt details _)
+ | n `elemNameSet` source_fvs
+ -- 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 (`elemNameSet` source_fvs) fs = get_bang t
+ | otherwise = emptyFVs
+
+ get_bang bty = extractHsTyNames (getBangType bty)
\end{code}
+@getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@
+rather than a declaration.
\begin{code}
-finalIfaceInfo ::
- IfaceCache -- iface cache
- -> [RnName] -- all imported names required
- -> [Module] -- directly imported modules
- -> PrimIO (VersionInfo, -- info about version numbers
- [Module]) -- special instance modules
+getWiredInGates :: Name -> FreeVars
+getWiredInGates name -- No classes are wired in
+ = case lookupNameEnv wiredInThingEnv name of
+ Just (AnId the_id) -> getWiredInGates_s (namesOfType (idType the_id))
-type VersionInfo = [(Module, Version, [(FAST_STRING, Version)])]
+ Just (ATyCon tc)
+ | isSynTyCon tc
+ -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars))
+ where
+ (tyvars,ty) = getSynTyConDefn tc
-finalIfaceInfo iface_var imps_reqd imp_mods
- = returnPrimIO ([], [])
+ other -> unitFV name
+
+getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names)
\end{code}
+\begin{code}
+getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty
+getInstDeclGates other = emptyFVs
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Getting in a declaration}
+%* *
+%*********************************************************
+
+\begin{code}
+importDecl :: Name -> RnMG ImportDeclResult
+
+data ImportDeclResult
+ = AlreadySlurped
+ | WiredIn
+ | Deferred
+ | HereItIs (Module, RdrNameTyClDecl)
+
+importDecl name
+ = -- Check if it was loaded before beginning this module
+ if isLocallyDefined name then
+ returnRn AlreadySlurped
+ else
+ checkAlreadyAvailable name `thenRn` \ done ->
+ if done then
+ returnRn AlreadySlurped
+ else
+
+ -- Check if we slurped it in while compiling this module
+ getIfacesRn `thenRn` \ ifaces ->
+ if name `elemNameSet` iSlurp ifaces then
+ returnRn AlreadySlurped
+ else
+
+ -- Don't slurp in decls from this module's own interface file
+ -- (Indeed, this shouldn't happen.)
+ if isLocallyDefined name then
+ addWarnRn (importDeclWarn name) `thenRn_`
+ returnRn AlreadySlurped
+ else
+
+ -- When we find a wired-in name we must load its home
+ -- module so that we find any instance decls lurking therein
+ if name `elemNameEnv` wiredInThingEnv then
+ loadHomeInterface doc name `thenRn_`
+ returnRn WiredIn
+
+ else getNonWiredInDecl name
+ where
+ doc = ptext SLIT("need home module for wired in thing") <+> ppr name
+
+getNonWiredInDecl :: Name -> RnMG ImportDeclResult
+getNonWiredInDecl needed_name
+ = traceRn doc_str `thenRn_`
+ loadHomeInterface doc_str needed_name `thenRn_`
+ getIfacesRn `thenRn` \ ifaces ->
+ case lookupNameEnv (iDecls ifaces) needed_name of
+
+{- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS
+ Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _)))
+ -- This case deals with deferred import of algebraic data types
+
+ | not opt_NoPruneTyDecls
+
+ && (opt_IgnoreIfacePragmas || ncons > 1)
+ -- We only defer if imported interface pragmas are ingored
+ -- or if it's not a product type.
+ -- Sole reason: The wrapper for a strict function may need to look
+ -- inside its arg, and hence need to see its arg type's constructors.
+
+ && not (getUnique tycon_name `elem` cCallishTyKeys)
+ -- Never defer ccall types; we have to unbox them,
+ -- and importing them does no harm
+
+
+ -> -- OK, so we're importing a deferrable data type
+ if needed_name == tycon_name
+ -- The needed_name is the TyCon of a data type decl
+ -- Record that it's slurped, put it in the deferred set
+ -- and don't return a declaration at all
+ setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
+ `addOneToNameSet` tycon_name})
+ version (AvailTC needed_name [needed_name])) `thenRn_`
+ returnRn Deferred
+
+ else
+ -- The needed name is a constructor of a data type decl,
+ -- getting a constructor, so remove the TyCon from the deferred set
+ -- (if it's there) and return the full declaration
+ setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
+ `delFromNameSet` tycon_name})
+ version avail) `thenRn_`
+ returnRn (HereItIs decl)
+ where
+ tycon_name = availName avail
+-}
+
+ Just (avail,_,decl)
+ -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
+ returnRn (HereItIs decl)
+
+ Nothing
+ -> addErrRn (getDeclErr needed_name) `thenRn_`
+ returnRn AlreadySlurped
+ where
+ doc_str = ptext SLIT("need decl for") <+> ppr needed_name
+
+{- OMIT FOR NOW
+getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
+getDeferredDecls
+ = getIfacesRn `thenRn` \ ifaces ->
+ let
+ decls_map = iDecls ifaces
+ deferred_names = nameSetToList (iDeferred ifaces)
+ get_abstract_decl n = case lookupNameEnv decls_map n of
+ Just (_, _, _, decl) -> decl
+ in
+ traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
+ returnRn (map get_abstract_decl deferred_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,
+\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
+
+\item if the wired-in name is another wired-in Id, it marks as ``occurrences''
+ the free vars of the Id's type.
+
+\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{Checking usage information}
+%* *
+%********************************************************
+
+@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}
+type RecompileRequired = Bool
+upToDate = False -- Recompile not required
+outOfDate = True -- Recompile required
+
+recompileRequired :: FilePath -- Only needed for debug msgs
+ -> Bool -- Source unchanged
+ -> Maybe ModIface -- Old interface, if any
+ -> RnMG RecompileRequired
+recompileRequired iface_path source_unchanged maybe_iface
+ = traceRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_`
+
+ -- CHECK WHETHER THE SOURCE HAS CHANGED
+ if not source_unchanged then
+ traceRn (nest 4 (text "Source file changed or recompilation check turned off")) `thenRn_`
+ returnRn outOfDate
+ else
+
+ -- CHECK WHETHER WE HAVE AN OLD IFACE
+ case maybe_iface of
+ Nothing -> traceRn (nest 4 (ptext SLIT("No old interface file"))) `thenRn_`
+ returnRn outOfDate ;
+
+ Just iface -> -- 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, _, _, whats_imported)
+ = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (iface, maybe_err) ->
+ case maybe_err of {
+ Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
+ ppr mod_name]) ;
+ -- Couldn't find or parse a module mentioned in the
+ -- old interface file. Don't complain -- it might just be that
+ -- the current module doesn't need that import and it's been deleted
+
+ Nothing ->
+ let
+ 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 ;
+
+ Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers ->
+
+ -- 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
+
+ -- CHECK RULES
+ if old_rule_vers /= vers_rules new_vers then
+ out_of_date (ptext SLIT("Rules changed"))
+ else
+
+ -- 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."))
+
+ }}
+ where
+ doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
+
+------------------------
+checkModuleVersion old_mod_vers new_vers
+ | vers_module new_vers == old_mod_vers
+ = up_to_date (ptext SLIT("Module version unchanged"))
+
+ | otherwise
+ = out_of_date (ptext SLIT("Module version has changed"))
+
+------------------------
+checkExportList Nothing new_vers = upToDate
+checkExportList (Just v) new_vers = v /= vers_exports new_vers
+
+------------------------
+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 -> returnRn upToDate
+ | otherwise -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
+
+up_to_date msg = traceRn msg `thenRn_` returnRn upToDate
+out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Errors}
+%* *
+%*********************************************************
\begin{code}
-noIfaceErr mod sty
- = ppCat [ppPStr SLIT("Could not find interface for:"), ppPStr mod]
+getDeclErr name
+ = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
+ ptext SLIT("from module") <+> quotes (ppr (nameModule name))
+ ]
-cannaeReadErr file sty
- = ppCat [ppPStr SLIT("Failed in reading file:"), ppStr file]
+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)]
\end{code}
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