#include "HsVersions.h"
-import CmdLineOpts ( DynFlags, opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas )
+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 RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
+import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl,
+ extractHsTyNames, extractHsCtxtTyNames,
+ tyClDeclFVs, ruleDeclFVs, instDeclFVs
+ )
import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface,
loadOrphanModules
)
-import RnSource ( rnTyClDecl, rnDecl )
+import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl )
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
+ nameModule, isLocalName, nameUnique,
+ NamedThing(..)
)
-import Module ( Module, ModuleEnv, mkVanillaModule,
+import Name ( elemNameEnv, delFromNameEnv )
+import Module ( Module, ModuleEnv,
moduleName, isModuleInThisPackage,
ModuleName, WhereFrom(..),
- emptyModuleEnv, lookupModuleEnvByName,
- extendModuleEnv_C, lookupWithDefaultModuleEnv
+ emptyModuleEnv,
+ extendModuleEnv_C, foldModuleEnv, lookupModuleEnv,
+ elemModuleSet, extendModuleSet
)
import NameSet
import PrelInfo ( wiredInThingEnv, fractionalClassKeys )
import FiniteMap
import Outputable
import Bag
-
-import List ( nub )
+import Util ( sortLt )
\end{code}
\begin{code}
getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)])
getInterfaceExports mod_name from
- = getHomeIfaceTableRn `thenRn` \ hit ->
- case lookupModuleEnvByName hit mod_name of {
- Just mi -> returnRn (mi_module mi, mi_exports mi) ;
- Nothing ->
-
- loadInterface doc_str mod_name from `thenRn` \ ifaces ->
- case lookupModuleEnvByName (iPIT ifaces) mod_name of
- Just mi -> returnRn (mi_module mi, mi_exports mi) ;
- -- loadInterface always puts something in the map
- -- even if it's a fake
- Nothing -> returnRn (mkVanillaModule mod_name, [])
- -- pprPanic "getInterfaceExports" (ppr mod_name)
- }
- 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, _, False)) <- 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
+ = loadInterface doc_str mod_name from `thenRn` \ iface ->
+ returnRn (mi_module iface, mi_exports iface)
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)
+ doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
\end{code}
%* *
%*********************************************************
-getImportVersions figures out what the ``usage information'' for this
+mkImportInof figures out what the ``usage information'' for this
moudule is; that is, what it must record in its interface file as the
-things it uses. 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
+things it uses.
+
+We produce a line for every module B below the module, A, currently being
+compiled:
+ import B <n> ;
+to record the fact that A does import B indireclty. This is used to decide
to look to look for B.hi rather than B.hi-boot when compiling a module that
imports A. This line says that A imports B, but uses nothing in it.
So we'll get an early bale-out when compiling A if B's version changes.
= 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 = nub [ m | ImportDecl m _ _ _ imp_list _ <- imports,
- import_all imp_list ]
-
- import_all (Just (False, _)) = False -- Imports are specified explicitly
- import_all other = True -- Everything is imported
-
- mod_map = iImpModInfo ifaces
- imp_names = iVSlurp ifaces
- pit = iPIT ifaces
-
- -- mv_map groups together all the things imported from a particular module.
+ 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 = foldr add_mv emptyModuleEnv imp_names
-
- add_mv name mv_map = addItem mv_map (nameModule name) name
-
- -- Build the result list by adding info for each module.
- -- For (a) a library module, we don't record it at all unless it contains orphans
- -- (We must never lose track of orphans.)
- --
- -- (b) a source-imported module, don't record the dependency at all
- --
- -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
- -- *all* the module's dependencies other than the loop-breakers. We use
- -- this info in findAndReadInterface to decide whether to look for a .hi file or
- -- a .hi-boot file.
+ 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
--
- -- This means we won't track version changes, or orphans, from .hi-boot files.
- -- The former is potentially rather bad news. It could be fixed by recording
- -- whether something is a boot file along with the usage info for it, but
- -- I can't be bothered just now.
-
- mk_imp_info mod_name (has_orphans, is_boot, opened) so_far
- | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
- -- This seems like a convenient place to check
- = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
- ptext SLIT("imports itself (perhaps indirectly)") )
- so_far
-
- | not opened -- We didn't even open the interface
- = -- 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
- -- information. The Nothing says that we didn't even open the interface
- -- file but we must still propagate the dependency info.
- -- The module in question must be a local module (in the same package)
- go_for_it NothingAtAll
-
-
- | is_lib_module && not has_orphans
- = so_far
-
- | is_lib_module -- Record the module version only
- = go_for_it (Everything module_vers)
-
- | otherwise
- = go_for_it whats_imported
-
- where
- go_for_it exports = (mod_name, has_orphans, is_boot, exports) : so_far
- mod_iface = lookupTableByModName hit pit mod_name `orElse` panic "mkImportInfo"
- mod = mi_module mod_iface
- is_lib_module = not (isModuleInThisPackage mod)
- version_info = mi_version mod_iface
- version_env = vers_decls version_info
- module_vers = vers_module version_info
-
- whats_imported = Specifically module_vers
- export_vers import_items
- (vers_rules version_info)
-
- import_items = [(n,v) | n <- lookupWithDefaultModuleEnv mv_map [] mod,
- let v = lookupNameEnv version_env n `orElse`
- pprPanic "mk_whats_imported" (ppr n)
- ]
- export_vers | moduleName mod `elem` import_all_mods
- = Just (vers_exports version_info)
- | otherwise
- = Nothing
+ -- 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
- import_info = foldFM mk_imp_info [] mod_map
- in
- traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_`
- returnRn import_info
+ 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)
-addItem :: ModuleEnv [a] -> Module -> a -> ModuleEnv [a]
-addItem fm mod x = extendModuleEnv_C add_item fm mod [x]
- where
- add_item xs _ = x:xs
+ | 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}
%*********************************************************
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 ->
-
- returnRn final_decls
+ closeDecls decls needed
-------------------------------------------------------
-- 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)
= 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) ->
+ 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
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
+ 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)
-
-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}
= 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
+ 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
+
-------------------------------------------------------
-------------------------------------------------------
-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)
+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}
= getIfacesRn `thenRn` \ ifaces ->
returnRn (iSlurp ifaces)
-recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
+recordSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped),
+ iSlurp = slurped_names,
+ iVSlurp = (imp_mods, imp_names) })
avail
- = let
- new_slurped_names = addAvailToNameSet slurped_names avail
- new_imp_names = availName avail : imp_names
- in
- ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
-
-recordLocalSlurps local_avails
+ = ASSERT2( not (isLocalName (availName avail)), ppr avail )
+ ifaces { iDecls = (decls_map', n_slurped+1),
+ iSlurp = new_slurped_names,
+ iVSlurp = new_vslurp }
+ where
+ decls_map' = foldl delFromNameEnv decls_map (availNames avail)
+ main_name = availName avail
+ mod = nameModule main_name
+ new_slurped_names = addAvailToNameSet slurped_names avail
+ new_vslurp | isModuleInThisPackage mod = (imp_mods, addOneToNameSet imp_names main_name)
+ | otherwise = (extendModuleSet imp_mods mod, imp_names)
+
+recordLocalSlurps new_names
= getIfacesRn `thenRn` \ ifaces ->
- let
- new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
- in
- setIfacesRn (ifaces { iSlurp = new_slurped_names })
+ setIfacesRn (ifaces { iSlurp = iSlurp ifaces `unionNameSets` new_names })
\end{code}
%*********************************************************
%* *
-\subsection{Deferred declarations}
+\subsection{Extracting the `gates'}
%* *
%*********************************************************
-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.
+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.
-\begin{code}
-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}
+ 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.
-%*********************************************************
-%* *
-\subsection{Extracting the `gates'}
-%* *
-%*********************************************************
+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 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, so we simply treat all
+previously-loaded classes as gates.
+Consructors and class operations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
+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}
-getGates source_fvs (IfaceSig _ ty _ _)
+getGates :: FreeVars -- Things mentioned in the source program
+ -> RenamedTyClDecl
+ -> FreeVars
+
+getGates source_fvs decl
+ = get_gates (\n -> n `elemNameSet` source_fvs) decl
+
+get_gates is_used (IfaceSig _ ty _ _)
= extractHsTyNames ty
-getGates source_fvs (ClassDecl ctxt cls tvs _ sigs _ _ _ )
+get_gates is_used (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
+ | is_used n = extractHsTyNames ty
+ | otherwise = emptyFVs
-- If we load any numeric class that doesn't have
-- Int as an instance, add Double to the gates.
| otherwise
= emptyFVs
-getGates source_fvs (TySynonym tycon tvs ty _)
- = delListFromNameSet (extractHsTyNames ty)
- (hsTyVarNames tvs)
+get_gates is_used (TySynonym tycon tvs ty _)
+ = delListFromNameSet (extractHsTyNames ty) (hsTyVarNames tvs)
-- A type synonym type constructor isn't a "gate" for instance decls
-getGates source_fvs (TyData _ ctxt tycon tvs cons _ _ _ _ _)
+get_gates is_used (TyData _ ctxt tycon tvs cons _ _ _ _ _)
= delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
(hsTyVarNames tvs)
`addOneToNameSet` tycon
where
get (ConDecl n _ tvs ctxt details _)
- | n `elemNameSet` source_fvs
+ | is_used n
-- If the constructor is method, get fvs from all its fields
= delListFromNameSet (get_details details `plusFV`
extractHsCtxtTyNames ctxt)
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_field (fs,t) | any is_used 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.
+@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded
+thing rather than a declaration.
\begin{code}
-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))
-
- Just (ATyCon tc)
- | isSynTyCon tc
- -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars))
- where
- (tyvars,ty) = getSynTyConDefn tc
-
- other -> unitFV name
+getWiredInGates :: TyThing -> FreeVars
+-- The TyThing is one that we already have in our type environment, either
+-- a) because the TyCon or Id is wired in, or
+-- b) from a previous compile
+-- Either way, we might have instance decls in the (persistent) collection
+-- of parsed-but-not-slurped instance decls that should be slurped in.
+-- This might be the first module that mentions both the type and the class
+-- for that instance decl, even though both the type and the class were
+-- mentioned in other modules, and hence are in the type environment
+
+getWiredInGates (AnId the_id) = namesOfType (idType the_id)
+getWiredInGates (AClass cl) = emptyFVs -- The superclasses must also be previously
+ -- loaded, and hence are automatically gates
+getWiredInGates (ATyCon tc)
+ | isSynTyCon tc = delListFromNameSet (namesOfType ty) (map getName tyvars)
+ | otherwise = unitFV (getName tc)
+ where
+ (tyvars,ty) = getSynTyConDefn tc
-getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names)
+getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty
\end{code}
\begin{code}
-getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty
-getInstDeclGates other = emptyFVs
+getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameInstDecl)]
+getImportedInstDecls gates
+ = -- First, load any orphan-instance modules that aren't aready loaded
+ -- Orphan-instance modules are recorded in the module dependecnies
+ getIfacesRn `thenRn` \ ifaces ->
+ let
+ orphan_mods =
+ [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)]
+ in
+ loadOrphanModules orphan_mods `thenRn_`
+
+ -- Now we're ready to grab the instance declarations
+ -- Find the un-gated ones and return them,
+ -- removing them from the bag kept in Ifaces
+ getIfacesRn `thenRn` \ ifaces ->
+ getTypeEnvRn `thenRn` \ lookup ->
+ let
+ (decls, new_insts) = selectGated gates lookup (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, InstDecl inst_ty _ _ _ _)
+ = case inst_ty of
+ HsForAllTy _ _ tau -> ppr tau
+ other -> ppr inst_ty
+
+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
+ rules = iRules ifaces
+ (decls, new_rules) = selectGated gates lookup rules
+ in
+ if null decls then
+ returnRn []
+ else
+ setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
+ traceRn (sep [text "getImportedRules:",
+ text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
+ returnRn decls
+
+selectGated gates lookup (decl_bag, n_slurped)
+ -- Select only those decls whose gates are *all* in 'gates'
+ -- or are a class in 'lookup'
+#ifdef DEBUG
+ | opt_NoPruneDecls -- Just to try the effect of not gating at all
+ = let
+ decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all
+ in
+ (decls, (emptyBag, n_slurped + length decls))
+
+ | otherwise
+#endif
+ = case foldrBag select ([], emptyBag) decl_bag of
+ (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls))
+ where
+ available n = n `elemNameSet` gates
+ || case lookup n of { Just (AClass c) -> True; other -> False }
+
+ select (reqd, decl) (yes, no)
+ | all available reqd = (decl:yes, no)
+ | otherwise = (yes, (reqd,decl) `consBag` no)
\end{code}
data ImportDeclResult
= AlreadySlurped
- | WiredIn
- | Deferred
+ | InTypeEnv TyThing
| HereItIs (Module, RdrNameTyClDecl)
importDecl name
- = -- Check if it was loaded before beginning this module
- checkAlreadyAvailable name `thenRn` \ done ->
- if done then
- returnRn AlreadySlurped
- else
-
- -- Check if we slurped it in while compiling this module
+ = -- 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
-
- -- 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` \ 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
+ -- 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)
- && (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.
+ | otherwise
+ -> returnRn (InTypeEnv ty_thing) ;
- && 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
+ Nothing ->
- 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
--}
+ -- 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 ->
+ -- STEP 4: Get the declaration out
+ let
+ (decls_map, _) = iDecls ifaces
+ in
+ case lookupNameEnv decls_map name of
Just (avail,_,decl)
-> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
returnRn (HereItIs decl)
Nothing
- -> addErrRn (getDeclErr needed_name) `thenRn_`
+ -> addErrRn (getDeclErr name) `thenRn_`
returnRn AlreadySlurped
+ }
where
- doc_str = ptext SLIT("need decl for") <+> ppr needed_name
+ wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name
+ nd_doc = ptext SLIT("need decl for") <+> ppr 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.
-
%********************************************************
%* *
upToDate = False -- Recompile not required
outOfDate = True -- Recompile required
-recompileRequired :: Module
+recompileRequired :: FilePath -- Only needed for debug msgs
-> Bool -- Source unchanged
- -> Maybe ModIface -- Old interface, if any
+ -> ModIface -- Old interface
-> RnMG RecompileRequired
-recompileRequired mod source_unchanged maybe_iface
- = traceRn (text "Considering whether compilation is required for" <+> ppr mod <> colon) `thenRn_`
+recompileRequired iface_path source_unchanged iface
+ = traceHiDiffsRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_`
-- CHECK WHETHER THE SOURCE HAS CHANGED
if not source_unchanged then
- traceRn (nest 4 (text "Source file changed or recompilation check turned off")) `thenRn_`
+ traceHiDiffsRn (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]
+ -- Source code unchanged and no errors yet... carry on
+ checkList [checkModUsage u | u <- mi_usages iface]
checkList :: [RnMG RecompileRequired] -> RnMG RecompileRequired
checkList [] = returnRn upToDate
-- 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` \ (ifaces, maybe_err) ->
+checkModUsage (mod_name, _, is_boot, whats_imported)
+ = -- Load the imported interface is possible
+ -- We use tryLoadInterface, because failure is not an error
+ -- (might just be that the old .hi file for this module is out of date)
+ -- We use ImportByUser/ImportByUserSource as the 'from' flag,
+ -- a) because we need to know whether to load the .hi-boot file
+ -- b) because loadInterface things matters are amiss if we
+ -- ImportBySystem an interface it knows nothing about
+ let
+ doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
+ from | is_boot = ImportByUserSource
+ | otherwise = ImportByUser
+ in
+ tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) ->
+
case maybe_err of {
Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
ppr mod_name]) ;
-- the current module doesn't need that import and it's been deleted
Nothing ->
-
- getHomeIfaceTableRn `thenRn` \ hit ->
let
- mod_details = lookupTableByModName hit (iPIT ifaces) mod_name
- `orElse` panic "checkModUsage"
- new_vers = mi_version mod_details
+ new_vers = mi_version iface
new_decl_vers = vers_decls new_vers
in
case whats_imported of { -- NothingAtAll dealt with earlier
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
| 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
+up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate
+out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate
\end{code}
= vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
ptext SLIT("from module") <+> quotes (ppr (nameModule name))
]
-
-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}
projects / ghc-hetmet.git / blobdiff