#include "HsVersions.h"
import HsSyn
-import RdrHsSyn ( RdrNameHsModule )
-import RnHsSyn ( RenamedHsModule, RenamedHsDecl, extractHsTyNames )
+import HsPragmas ( DataPragmas(..) )
+import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation )
+import RnHsSyn ( RenamedHsModule, RenamedHsDecl,
+ extractHsTyNames, extractHsCtxtTyNames
+ )
-import CmdLineOpts ( opt_HiMap, opt_D_show_rn_trace,
- opt_D_dump_rn, opt_D_show_rn_stats,
- opt_WarnUnusedBinds, opt_WarnUnusedImports
- )
+import CmdLineOpts ( DynFlags, DynFlag(..) )
import RnMonad
import RnNames ( getGlobalNames )
-import RnSource ( rnIfaceDecl, rnSourceDecls )
-import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules,
- getDeferredDataDecls,
- mkSearchPath, getSlurpedNames, getRnStats
+import RnSource ( rnSourceDecls, rnDecl )
+import RnIfaces ( getImportedInstDecls, importDecl, mkImportInfo,
+ getInterfaceExports,
+ getImportedRules, getSlurped, removeContext,
+ ImportDeclResult(..), findAndReadIface
+ )
+import RnEnv ( availName, availsToNameSet,
+ emptyAvailEnv, unitAvailEnv, availEnvElts, plusAvailEnv, sortAvails,
+ warnUnusedImports, warnUnusedLocalBinds, warnUnusedModules,
+ lookupOrigNames, unknownNameErr,
+ FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs, addOneFV
)
-import RnEnv ( addImplicitOccsRn, availName, availNames, availsToNameSet,
- warnUnusedTopNames
+import Module ( Module, ModuleName, WhereFrom(..),
+ moduleNameUserString, moduleName, mkModuleInThisPackage,
+ lookupModuleEnv
)
-import Name ( Name, isLocallyDefined,
- NamedThing(..), ImportReason(..), Provenance(..),
- nameModule, pprModule, pprOccName, nameOccName,
- getNameProvenance, occNameUserString,
+import Name ( Name, isLocallyDefined, NamedThing(..), getSrcLoc,
+ nameOccName, nameUnique, nameModule,
+ isUserExportedName, toRdrName,
+ mkNameEnv, nameEnvElts, extendNameEnv
)
-import RdrName ( RdrName )
+import OccName ( occNameFlavour, isValOcc )
+import Id ( idType )
+import TyCon ( isSynTyCon, getSynTyConDefn )
import NameSet
-import TyCon ( TyCon )
-import PrelMods ( mAIN, pREL_MAIN )
-import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
-import PrelInfo ( ioTyCon_NAME, thinAirIdNames )
-import ErrUtils ( pprBagOfErrors, pprBagOfWarnings,
- doIfSet, dumpIfSet, ghcExit
+import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon )
+import PrelNames ( mAIN_Name, pREL_MAIN_Name, pRELUDE_Name,
+ ioTyCon_RDR,
+ unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
+ eqString_RDR
+ )
+import PrelInfo ( fractionalClassKeys, derivingOccurrences, wiredInThingEnv )
+import Type ( namesOfType, funTyCon )
+import ErrUtils ( printErrorsAndWarnings, dumpIfSet, ghcExit )
+import BasicTypes ( Version, initialVersion )
+import Bag ( isEmptyBag, bagToList )
+import FiniteMap ( FiniteMap, eltsFM, fmToList, emptyFM, lookupFM,
+ addToFM_C, elemFM, addToFM
)
-import Bag ( isEmptyBag )
-import FiniteMap ( fmToList, delListFromFM )
import UniqSupply ( UniqSupply )
-import Util ( equivClasses )
-import Maybes ( maybeToBool )
+import UniqFM ( lookupUFM )
+import SrcLoc ( noSrcLoc )
+import Maybes ( maybeToBool, expectJust )
import Outputable
+import IO ( openFile, IOMode(..) )
+import HscTypes ( Finder, PersistentCompilerState, HomeIfaceTable, HomeSymbolTable,
+ ModIface(..), TyThing(..),
+ GlobalRdrEnv, AvailEnv, Avails, GenAvailInfo(..), AvailInfo,
+ Provenance(..), pprNameProvenance, ImportReason(..),
+ lookupDeprec
+ )
+import List ( partition, nub )
\end{code}
\begin{code}
-renameModule :: UniqSupply
- -> RdrNameHsModule
- -> IO (Maybe
- ( RenamedHsModule -- Output, after renaming
- , InterfaceDetails -- Interface; for interface file generatino
- , RnNameSupply -- Final env; for renaming derivings
- , [Module] -- Imported modules; for profiling
- ))
-
-renameModule us this_mod@(HsModule mod_name vers exports imports local_decls loc)
+renameModule :: DynFlags -> Finder
+ -> HomeIfaceTable -> HomeSymbolTable
+ -> PersistentCompilerState
+ -> Module -> RdrNameHsModule
+ -> IO (PersistentCompilerState, Maybe ModIface)
+ -- The mi_decls in the ModIface include
+ -- ones imported from packages too
+
+renameModule dflags finder hit hst old_pcs this_module
+ this_mod@(HsModule _ _ _ _ _ _ loc)
= -- Initialise the renamer monad
- initRn mod_name us (mkSearchPath opt_HiMap) loc
- (rename this_mod) >>=
- \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) ->
+ do {
+ ((maybe_rn_stuff, dump_action), (rn_warns_bag, rn_errs_bag), new_pcs)
+ <- initRn dflags finder hit hst old_pcs this_module loc (rename this_module this_mod) ;
-- Check for warnings
- doIfSet (not (isEmptyBag rn_warns_bag))
- (printErrs (pprBagOfWarnings rn_warns_bag)) >>
-
- -- Check for errors; exit if so
- doIfSet (not (isEmptyBag rn_errs_bag))
- (printErrs (pprBagOfErrors rn_errs_bag) >>
- ghcExit 1
- ) >>
-
- -- Dump output, if any
- (case maybe_rn_stuff of
- Nothing -> return ()
- Just results@(rn_mod, _, _, _)
- -> dumpIfSet opt_D_dump_rn "Renamer:"
- (ppr rn_mod)
- ) >>
+ printErrorsAndWarnings (rn_warns_bag, rn_errs_bag) ;
+
+ -- Dump any debugging output
+ dump_action ;
-- Return results
- return maybe_rn_stuff
+ if not (isEmptyBag rn_errs_bag) then
+ return (old_pcs, Nothing)
+ else
+ return (new_pcs, maybe_rn_stuff)
+ }
\end{code}
-
\begin{code}
-rename this_mod@(HsModule mod_name vers exports imports local_decls loc)
+rename :: Module -> RdrNameHsModule -> RnMG (Maybe ModIface, IO ())
+rename this_module this_mod@(HsModule mod_name vers exports imports local_decls mod_deprec loc)
= -- FIND THE GLOBAL NAME ENVIRONMENT
getGlobalNames this_mod `thenRn` \ maybe_stuff ->
-- CHECK FOR EARLY EXIT
- if not (maybeToBool maybe_stuff) then
- -- Everything is up to date; no need to recompile further
- rnStats [] `thenRn_`
- returnRn Nothing
- else
- let
- Just (export_env, rn_env, global_avail_env) = maybe_stuff
- in
+ case maybe_stuff of {
+ Nothing -> -- Everything is up to date; no need to recompile further
+ rnDump [] [] `thenRn` \ dump_action ->
+ returnRn (Nothing, dump_action) ;
+
+ Just (gbl_env, local_gbl_env, export_avails, global_avail_env) ->
+
+ -- DEAL WITH DEPRECATIONS
+ rnDeprecs local_gbl_env mod_deprec local_decls `thenRn` \ my_deprecs ->
+
+ -- DEAL WITH LOCAL FIXITIES
+ fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
-- RENAME THE SOURCE
- initRnMS rn_env SourceMode (
- addImplicits mod_name `thenRn_`
+ initRnMS gbl_env local_fixity_env SourceMode (
rnSourceDecls local_decls
- ) `thenRn` \ (rn_local_decls, fvs) ->
+ ) `thenRn` \ (rn_local_decls, source_fvs) ->
-- SLURP IN ALL THE NEEDED DECLARATIONS
- slurpDecls rn_local_decls `thenRn` \ rn_all_decls ->
+ implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
+ let
+ -- The export_fvs make the exported names look just as if they
+ -- occurred in the source program. For the reasoning, see the
+ -- comments with RnIfaces.getImportVersions.
+ -- We only need the 'parent name' of the avail;
+ -- that's enough to suck in the declaration.
+ export_fvs = mkNameSet (map availName export_avails)
+ real_source_fvs = source_fvs `plusFV` export_fvs
+
+ slurp_fvs = implicit_fvs `plusFV` real_source_fvs
+ -- It's important to do the "plus" this way round, so that
+ -- when compiling the prelude, locally-defined (), Bool, etc
+ -- override the implicit ones.
+ in
+ slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls ->
-- EXIT IF ERRORS FOUND
- checkErrsRn `thenRn` \ no_errs_so_far ->
+ rnDump rn_imp_decls rn_local_decls `thenRn` \ dump_action ->
+ checkErrsRn `thenRn` \ no_errs_so_far ->
if not no_errs_so_far then
-- Found errors already, so exit now
- rnStats [] `thenRn_`
- returnRn Nothing
+ returnRn (Nothing, dump_action)
else
-- GENERATE THE VERSION/USAGE INFO
- getImportVersions mod_name exports `thenRn` \ import_versions ->
- getNameSupplyRn `thenRn` \ name_supply ->
-
- -- REPORT UNUSED NAMES
- reportUnusedNames rn_env global_avail_env
- export_env
- fvs `thenRn_`
-
- -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
- -- The "special instance" modules are those modules that contain instance
- -- declarations that contain no type constructor or class that was declared
- -- in that module.
- getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
- let
- special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
- all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
- ]
- special_inst_mods | null special_inst_decls = imported_special_inst_mods
- | otherwise = mod_name : imported_special_inst_mods
- in
-
-
+ mkImportInfo mod_name imports `thenRn` \ my_usages ->
+
-- RETURN THE RENAMED MODULE
+ getNameSupplyRn `thenRn` \ name_supply ->
+ getIfacesRn `thenRn` \ ifaces ->
let
- import_mods = [mod | ImportDecl mod _ _ _ _ <- imports]
+ direct_import_mods :: [ModuleName]
+ direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports]
- renamed_module = HsModule mod_name vers
- trashed_exports trashed_imports
- rn_all_decls
- loc
+ -- *don't* just pick the forward edges. It's entirely possible
+ -- that a module is only reachable via back edges.
+ user_import ImportByUser = True
+ user_import ImportByUserSource = True
+ user_import _ = False
+
+ -- Export only those fixities that are for names that are
+ -- (a) defined in this module
+ -- (b) exported
+ exported_fixities
+ = mkNameEnv [ (name, fixity)
+ | FixitySig name fixity loc <- nameEnvElts local_fixity_env,
+ isUserExportedName name
+ ]
+
+
+ -- Sort the exports to make them easier to compare for versions
+ my_exports = sortAvails export_avails
+
+ mod_iface = ModIface { mi_module = this_module,
+ mi_version = panic "mi_version: not filled in yet",
+ mi_orphan = any isOrphanDecl rn_local_decls,
+ mi_exports = my_exports,
+ mi_usages = my_usages,
+ mi_fixities = exported_fixities,
+ mi_deprecs = my_deprecs,
+ mi_decls = rn_local_decls ++ rn_imp_decls
+ }
in
- rnStats rn_all_decls `thenRn_`
- returnRn (Just (renamed_module,
- (import_versions, export_env, special_inst_mods),
- name_supply,
- import_mods))
+
+ -- REPORT UNUSED NAMES, AND DEBUG DUMP
+ reportUnusedNames mod_name direct_import_mods
+ gbl_env global_avail_env
+ export_avails source_fvs
+ rn_imp_decls `thenRn_`
+
+ returnRn (Just mod_iface, dump_action) }
where
trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
trashed_imports = {-trace "rnSource:trashed_imports"-} []
\end{code}
-@addImplicits@ forces the renamer to slurp in some things which aren't
+@implicitFVs@ forces the renamer to slurp in some things which aren't
mentioned explicitly, but which might be needed by the type checker.
\begin{code}
-addImplicits mod_name
- = addImplicitOccsRn (implicit_main ++ default_tys ++ thinAirIdNames)
+implicitFVs mod_name decls
+ = lookupOrigNames implicit_occs `thenRn` \ implicit_names ->
+ returnRn (mkNameSet (map getName default_tycons) `plusFV`
+ implicit_names)
where
- -- Add occurrences for Int, Double, and (), because they
+ -- Add occurrences for Int, and (), because they
-- are the types to which ambigious type variables may be defaulted by
-- the type checker; so they won't always appear explicitly.
-- [The () one is a GHC extension for defaulting CCall results.]
- default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon ]
+ -- ALSO: funTyCon, since it occurs implicitly everywhere!
+ -- (we don't want to be bothered with making funTyCon a
+ -- free var at every function application!)
+ -- Double is dealt with separately in getGates
+ default_tycons = [unitTyCon, funTyCon, boolTyCon, intTyCon]
-- Add occurrences for IO or PrimIO
- implicit_main | mod_name == mAIN
- || mod_name == pREL_MAIN = [ioTyCon_NAME]
- | otherwise = []
-\end{code}
+ implicit_main | mod_name == mAIN_Name
+ || mod_name == pREL_MAIN_Name = [ioTyCon_RDR]
+ | otherwise = []
+
+ -- Now add extra "occurrences" for things that
+ -- the deriving mechanism, or defaulting, will later need in order to
+ -- generate code
+ implicit_occs = string_occs ++ foldr ((++) . get) implicit_main decls
+ -- Virtually every program has error messages in it somewhere
+ string_occs = [unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
+ eqString_RDR]
+
+ get (TyClD (TyData _ _ _ _ _ _ (Just deriv_classes) _ _ _ _))
+ = concat (map get_deriv deriv_classes)
+ get other = []
+
+ get_deriv cls = case lookupUFM derivingOccurrences cls of
+ Nothing -> []
+ Just occs -> occs
+\end{code}
\begin{code}
-slurpDecls decls
- = -- First of all, get all the compulsory decls
- slurp_compulsories decls `thenRn` \ decls1 ->
+isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _))
+ = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames (removeContext inst_ty)))
+ -- The 'removeContext' is because of
+ -- instance Foo a => Baz T where ...
+ -- The decl is an orphan if Baz and T are both not locally defined,
+ -- even if Foo *is* locally defined
- -- Next get the optional ones
- closeDecls optional_mode decls1 `thenRn` \ decls2 ->
+isOrphanDecl (RuleD (HsRule _ _ _ lhs _ _))
+ = check lhs
+ where
+ -- At the moment we just check for common LHS forms
+ -- Expand as necessary. Getting it wrong just means
+ -- more orphans than necessary
+ check (HsVar v) = not (isLocallyDefined v)
+ check (HsApp f a) = check f && check a
+ check (HsLit _) = False
+ check (HsOverLit _) = False
+ check (OpApp l o _ r) = check l && check o && check r
+ check (NegApp e _) = check e
+ check (HsPar e) = check e
+ check (SectionL e o) = check e && check o
+ check (SectionR o e) = check e && check o
- -- Finally get those deferred data type declarations
- getDeferredDataDecls `thenRn` \ data_decls ->
- mapRn (rn_data_decl compulsory_mode) data_decls `thenRn` \ rn_data_decls ->
+ check other = True -- Safe fall through
- -- Done
- returnRn (rn_data_decls ++ decls2)
+isOrphanDecl other = False
+\end{code}
+
+\begin{code}
+dupDefaultDeclErrRn (DefaultDecl _ locn1 : dup_things)
+ = pushSrcLocRn locn1 $
+ addErrRn msg
where
- compulsory_mode = InterfaceMode Compulsory
- optional_mode = InterfaceMode Optional
-
- -- The "slurp_compulsories" function is a loop that alternates
- -- between slurping compulsory decls and slurping the instance
- -- decls thus made relavant.
- -- We *must* loop again here. Why? Two reasons:
- -- (a) an instance decl will give rise to an unresolved dfun, whose
- -- decl we must slurp to get its version number; that's the version
- -- number for the whole instance decl. (And its unfolding might mention new
- -- unresolved names.)
- -- (b) an instance decl might give rise to a new unresolved class,
- -- whose decl we must slurp, which might let in some new instance decls,
- -- and so on. Example: instance Foo a => Baz [a] where ...
- slurp_compulsories decls
- = closeDecls compulsory_mode decls `thenRn` \ decls1 ->
-
- -- Instance decls still pending?
- getImportedInstDecls `thenRn` \ inst_decls ->
- if null inst_decls then
- -- No, none
- returnRn decls1
- else
- -- Yes, there are some, so rename them and loop
- traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
- `thenRn_`
- mapRn (rn_inst_decl compulsory_mode) inst_decls `thenRn` \ new_inst_decls ->
- slurp_compulsories (new_inst_decls ++ decls1)
+ msg = hang (ptext SLIT("Multiple default declarations"))
+ 4 (vcat (map pp dup_things))
+ pp (DefaultDecl _ locn) = ptext SLIT("here was another default declaration") <+> ppr locn
\end{code}
+
+%*********************************************************
+%* *
+\subsection{Slurping declarations}
+%* *
+%*********************************************************
+
\begin{code}
-closeDecls :: RnMode
- -> [RenamedHsDecl] -- Declarations got so far
- -> RnMG [RenamedHsDecl] -- input + extra decls slurped
- -- The monad includes a list of possibly-unresolved Names
- -- This list is empty when closeDecls returns
-
-closeDecls mode decls
- = popOccurrenceName mode `thenRn` \ maybe_unresolved ->
- case maybe_unresolved of
-
- -- No more unresolved names
- Nothing -> returnRn decls
+-------------------------------------------------------
+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 ->
+
+ 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
+ -- 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
- -- An unresolved name
- Just name_w_loc
- -> -- Slurp its declaration, if any
--- traceRn (sep [ptext SLIT("Considering"), ppr name_w_loc]) `thenRn_`
- importDecl name_w_loc mode `thenRn` \ maybe_decl ->
- case maybe_decl of
-
- -- No declaration... (wired in thing or optional)
- Nothing -> closeDecls mode decls
-
- -- Found a declaration... rename it
- Just decl -> rn_iface_decl mod_name mode decl `thenRn` \ new_decl ->
- closeDecls mode (new_decl : decls)
- where
- mod_name = nameModule (fst name_w_loc)
-
-rn_iface_decl mod_name mode decl
- = setModuleRn mod_name $
- initRnMS emptyRnEnv mode (rnIfaceDecl decl)
-
-rn_inst_decl mode (mod_name,decl) = rn_iface_decl mod_name mode (InstD decl)
-rn_data_decl mode (mod_name,ty_decl) = rn_iface_decl mod_name mode (TyClD ty_decl)
+ HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (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}
+
\begin{code}
-reportUnusedNames (RnEnv gbl_env _) avail_env (ExportEnv export_avails _) mentioned_names
- | not (opt_WarnUnusedBinds || opt_WarnUnusedImports)
- = returnRn ()
+-------------------------------------------------------
+-- 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
- = let
- used_names = mentioned_names `unionNameSets` availsToNameSet export_avails
-
- -- Now, a use of C implies a use of T,
- -- if C was brought into scope by T(..) or T(C)
- really_used_names = used_names `unionNameSets`
- mkNameSet [ availName avail
- | sub_name <- nameSetToList used_names,
- let avail = case lookupNameEnv avail_env sub_name of
- Just avail -> avail
- Nothing -> pprTrace "r.u.n" (ppr sub_name) $
- Avail sub_name
- ]
-
- defined_names = mkNameSet (concat (rdrEnvElts gbl_env))
- defined_but_not_used = nameSetToList (defined_names `minusNameSet` really_used_names)
-
- -- Filter out the ones only defined implicitly
- bad_guys = filter reportableUnusedName defined_but_not_used
- in
- warnUnusedTopNames bad_guys `thenRn_`
+ = 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 -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (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)
+\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}
+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 NoDataPragmas 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}
+getGates source_fvs (SigD (IfaceSig _ ty _ _))
+ = extractHsTyNames ty
+
+getGates source_fvs (TyClD (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 (TyClD (TySynonym tycon tvs ty _))
+ = delListFromNameSet (extractHsTyNames ty)
+ (hsTyVarNames tvs)
+ -- A type synonym type constructor isn't a "gate" for instance decls
+
+getGates source_fvs (TyClD (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)
+
+getGates source_fvs other_decl = emptyFVs
+\end{code}
+
+@getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@
+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_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{Fixities}
+%* *
+%*********************************************************
+
+\begin{code}
+fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
+fixitiesFromLocalDecls gbl_env decls
+ = doptRn Opt_WarnUnusedBinds `thenRn` \ warn_unused ->
+ foldlRn (getFixities warn_unused) emptyNameEnv decls `thenRn` \ env ->
+ traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env)))
+ `thenRn_`
+ returnRn env
+ where
+ getFixities :: Bool -> LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
+ getFixities warn_uu acc (FixD fix)
+ = fix_decl warn_uu acc fix
+
+ getFixities warn_uu acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ _ ))
+ = foldlRn (fix_decl warn_uu) acc [sig | FixSig sig <- sigs]
+ -- Get fixities from class decl sigs too.
+ getFixities warn_uu acc other_decl
+ = returnRn acc
+
+ fix_decl warn_uu acc sig@(FixitySig rdr_name fixity loc)
+ = -- Check for fixity decl for something not declared
+ case lookupRdrEnv gbl_env rdr_name of {
+ Nothing | warn_uu
+ -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity))
+ `thenRn_` returnRn acc
+ | otherwise -> returnRn acc ;
+
+ Just ((name,_):_) ->
+
+ -- Check for duplicate fixity decl
+ case lookupNameEnv acc name of {
+ Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc')
+ `thenRn_` returnRn acc ;
+
+ Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
+ }}
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Deprecations}
+%* *
+%*********************************************************
+
+For deprecations, all we do is check that the names are in scope.
+It's only imported deprecations, dealt with in RnIfaces, that we
+gather them together.
+
+\begin{code}
+rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
+ -> [RdrNameHsDecl] -> RnMG [RdrNameDeprecation]
+rnDeprecs gbl_env mod_deprec decls
+ = mapRn rn_deprec deprecs `thenRn_`
+ returnRn (extra_deprec ++ deprecs)
+ where
+ deprecs = [d | DeprecD d <- decls]
+ extra_deprec = case mod_deprec of
+ Nothing -> []
+ Just txt -> [Deprecation (IEModuleContents undefined) txt noSrcLoc]
+
+ rn_deprec (Deprecation ie txt loc)
+ = pushSrcLocRn loc $
+ mapRn check (ieNames ie)
+
+ check n = case lookupRdrEnv gbl_env n of
+ Nothing -> addErrRn (unknownNameErr n)
+ Just _ -> returnRn ()
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Unused names}
+%* *
+%*********************************************************
+
+\begin{code}
+reportUnusedNames :: ModuleName -> [ModuleName]
+ -> GlobalRdrEnv -> AvailEnv
+ -> Avails -> NameSet -> [RenamedHsDecl]
+ -> RnMG ()
+reportUnusedNames mod_name direct_import_mods
+ gbl_env avail_env
+ export_avails mentioned_names
+ imported_decls
+ = warnUnusedModules unused_imp_mods `thenRn_`
+ warnUnusedLocalBinds bad_locals `thenRn_`
+ warnUnusedImports bad_imp_names `thenRn_`
+ printMinimalImports mod_name minimal_imports `thenRn_`
+ warnDeprecations really_used_names `thenRn_`
returnRn ()
-reportableUnusedName :: Name -> Bool
-reportableUnusedName name
- = explicitlyImported (getNameProvenance name) &&
- not (startsWithUnderscore (occNameUserString (nameOccName name)))
where
- explicitlyImported (LocalDef _ _) = True -- Report unused defns of local vars
- explicitlyImported (NonLocalDef (UserImport _ _ expl) _) = expl -- Report unused explicit imports
- explicitlyImported other = False -- Don't report others
-
- -- Haskell 98 encourages compilers to suppress warnings about
- -- unused names in a pattern if they start with "_".
- startsWithUnderscore ('_' : _) = True -- Suppress warnings for names starting
- startsWithUnderscore other = False -- with an underscore
-
-rnStats :: [RenamedHsDecl] -> RnMG ()
-rnStats all_decls
- | opt_D_show_rn_trace ||
- opt_D_show_rn_stats ||
- opt_D_dump_rn
- = getRnStats all_decls `thenRn` \ msg ->
- ioToRnMG (printErrs msg) `thenRn_`
- returnRn ()
-
- | otherwise = returnRn ()
+ used_names = mentioned_names `unionNameSets` availsToNameSet export_avails
+
+ -- Now, a use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
+ really_used_names = used_names `unionNameSets`
+ mkNameSet [ parent_name
+ | sub_name <- nameSetToList used_names
+
+ -- Usually, every used name will appear in avail_env, but there
+ -- is one time when it doesn't: tuples and other built in syntax. When you
+ -- write (a,b) that gives rise to a *use* of "(,)", so that the
+ -- instances will get pulled in, but the tycon "(,)" isn't actually
+ -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
+ -- similarly, 3.5 gives rise to an implcit use of :%
+ -- Hence the silent 'False' in all other cases
+
+ , Just parent_name <- [case lookupNameEnv avail_env sub_name of
+ Just (AvailTC n _) -> Just n
+ other -> Nothing]
+ ]
+
+ defined_names, defined_and_used, defined_but_not_used :: [(Name,Provenance)]
+ defined_names = concat (rdrEnvElts gbl_env)
+ (defined_and_used, defined_but_not_used) = partition used defined_names
+ used (name,_) = not (name `elemNameSet` really_used_names)
+
+ -- Filter out the ones only defined implicitly
+ bad_locals :: [Name]
+ bad_locals = [n | (n,LocalDef) <- defined_but_not_used]
+
+ bad_imp_names :: [(Name,Provenance)]
+ bad_imp_names = [(n,p) | (n,p@(NonLocalDef (UserImport mod _ True) _)) <- defined_but_not_used,
+ not (module_unused mod)]
+
+ -- inst_mods are directly-imported modules that
+ -- contain instance decl(s) that the renamer decided to suck in
+ -- It's not necessarily redundant to import such modules.
+ --
+ -- NOTE: Consider
+ -- module This
+ -- import M ()
+ --
+ -- The import M() is not *necessarily* redundant, even if
+ -- we suck in no instance decls from M (e.g. it contains
+ -- no instance decls, or This contains no code). It may be
+ -- that we import M solely to ensure that M's orphan instance
+ -- decls (or those in its imports) are visible to people who
+ -- import This. Sigh.
+ -- There's really no good way to detect this, so the error message
+ -- in RnEnv.warnUnusedModules is weakened instead
+ inst_mods :: [ModuleName]
+ inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
+ let m = moduleName (nameModule dfun),
+ m `elem` direct_import_mods
+ ]
+
+ -- To figure out the minimal set of imports, start with the things
+ -- that are in scope (i.e. in gbl_env). Then just combine them
+ -- into a bunch of avails, so they are properly grouped
+ minimal_imports :: FiniteMap ModuleName AvailEnv
+ minimal_imports0 = emptyFM
+ minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
+ minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
+
+ add_name (n,NonLocalDef (UserImport m _ _) _) acc = addToFM_C plusAvailEnv acc (moduleName (nameModule n))
+ (unitAvailEnv (mk_avail n))
+ add_name (n,other_prov) acc = acc
+
+ mk_avail n = case lookupNameEnv avail_env n of
+ Just (AvailTC m _) | n==m -> AvailTC n [n]
+ | otherwise -> AvailTC m [n,m]
+ Just avail -> Avail n
+ Nothing -> pprPanic "mk_avail" (ppr n)
+
+ add_inst_mod m acc
+ | m `elemFM` acc = acc -- We import something already
+ | otherwise = addToFM acc m emptyAvailEnv
+ -- Add an empty collection of imports for a module
+ -- from which we have sucked only instance decls
+
+ -- unused_imp_mods are the directly-imported modules
+ -- that are not mentioned in minimal_imports
+ unused_imp_mods = [m | m <- direct_import_mods,
+ not (maybeToBool (lookupFM minimal_imports m)),
+ m /= pRELUDE_Name]
+
+ module_unused :: Module -> Bool
+ module_unused mod = moduleName mod `elem` unused_imp_mods
+
+
+warnDeprecations used_names
+ = doptRn Opt_WarnDeprecations `thenRn` \ warn_drs ->
+ if not warn_drs then returnRn () else
+
+ getIfacesRn `thenRn` \ ifaces ->
+ getHomeIfaceTableRn `thenRn` \ hit ->
+ let
+ pit = iPIT ifaces
+ deprecs = [ (n,txt)
+ | n <- nameSetToList used_names,
+ Just txt <- [lookup_deprec hit pit n] ]
+ in
+ mapRn_ warnDeprec deprecs
+
+ where
+ lookup_deprec hit pit n
+ = case lookupModuleEnv hit mod of
+ Just iface -> lookupDeprec iface n
+ Nothing -> case lookupModuleEnv pit mod of
+ Just iface -> lookupDeprec iface n
+ Nothing -> pprPanic "warnDeprecations:" (ppr n)
+ where
+ mod = nameModule n
+
+-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
+printMinimalImports mod_name imps
+ = doptRn Opt_D_dump_minimal_imports `thenRn` \ dump_minimal ->
+ if not dump_minimal then returnRn () else
+
+ mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
+ ioToRnM (do { h <- openFile filename WriteMode ;
+ printForUser h (vcat (map ppr_mod_ie mod_ies))
+ }) `thenRn_`
+ returnRn ()
+ where
+ filename = moduleNameUserString mod_name ++ ".imports"
+ ppr_mod_ie (mod_name, ies)
+ | mod_name == pRELUDE_Name
+ = empty
+ | otherwise
+ = ptext SLIT("import") <+> ppr mod_name <>
+ parens (fsep (punctuate comma (map ppr ies)))
+
+ to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
+ returnRn (mod, ies)
+
+ to_ie :: AvailInfo -> RnMG (IE Name)
+ to_ie (Avail n) = returnRn (IEVar n)
+ to_ie (AvailTC n [m]) = ASSERT( n==m )
+ returnRn (IEThingAbs n)
+ to_ie (AvailTC n ns) = getInterfaceExports (moduleName (nameModule n))
+ ImportBySystem `thenRn` \ (_, avails) ->
+ case [ms | AvailTC m ms <- avails, m == n] of
+ [ms] | all (`elem` ns) ms -> returnRn (IEThingAll n)
+ | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
+ other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
+ returnRn (IEVar n)
+
+rnDump :: [RenamedHsDecl] -- Renamed imported decls
+ -> [RenamedHsDecl] -- Renamed local decls
+ -> RnMG (IO ())
+rnDump imp_decls local_decls
+ = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace ->
+ doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats ->
+ doptRn Opt_D_dump_rn `thenRn` \ dump_rn ->
+ if dump_rn_trace || dump_rn_stats || dump_rn then
+ getRnStats imp_decls `thenRn` \ stats_msg ->
+ returnRn (printErrs stats_msg >>
+ dumpIfSet dump_rn "Renamer:"
+ (vcat (map ppr (local_decls ++ imp_decls))))
+ else
+ returnRn (return ())
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Statistics}
+%* *
+%*********************************************************
+
+\begin{code}
+getRnStats :: [RenamedHsDecl] -> RnMG SDoc
+getRnStats imported_decls
+ = getIfacesRn `thenRn` \ ifaces ->
+ let
+ n_mods = length [() | (_, _, True) <- eltsFM (iImpModInfo ifaces)]
+
+ decls_read = [decl | (avail, True, (_,decl)) <- nameEnvElts (iDecls ifaces),
+ -- Data, newtype, and class decls are in the decls_fm
+ -- under multiple names; the tycon/class, and each
+ -- constructor/class op too.
+ -- The 'True' selects just the 'main' decl
+ not (isLocallyDefined (availName avail))
+ ]
+
+ (cd_rd, dd_rd, nd_rd, sd_rd, vd_rd, _) = count_decls decls_read
+ (cd_sp, dd_sp, nd_sp, sd_sp, vd_sp, id_sp) = count_decls imported_decls
+
+ unslurped_insts = iInsts ifaces
+ inst_decls_unslurped = length (bagToList unslurped_insts)
+ inst_decls_read = id_sp + inst_decls_unslurped
+
+ stats = vcat
+ [int n_mods <+> text "interfaces read",
+ hsep [ int cd_sp, text "class decls imported, out of",
+ int cd_rd, text "read"],
+ hsep [ int dd_sp, text "data decls imported, out of",
+ int dd_rd, text "read"],
+ hsep [ int nd_sp, text "newtype decls imported, out of",
+ int nd_rd, text "read"],
+ hsep [int sd_sp, text "type synonym decls imported, out of",
+ int sd_rd, text "read"],
+ hsep [int vd_sp, text "value signatures imported, out of",
+ int vd_rd, text "read"],
+ hsep [int id_sp, text "instance decls imported, out of",
+ int inst_decls_read, text "read"],
+ text "cls dcls slurp" <+> fsep (map (ppr . tyClDeclName)
+ [d | TyClD d <- imported_decls, isClassDecl d]),
+ text "cls dcls read" <+> fsep (map (ppr . tyClDeclName)
+ [d | TyClD d <- decls_read, isClassDecl d])]
+ in
+ returnRn (hcat [text "Renamer stats: ", stats])
+
+count_decls decls
+ = (class_decls,
+ data_decls,
+ newtype_decls,
+ syn_decls,
+ val_decls,
+ inst_decls)
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ (class_decls, data_decls, newtype_decls, syn_decls) = countTyClDecls tycl_decls
+
+ val_decls = length [() | SigD _ <- decls]
+ inst_decls = length [() | InstD _ <- decls]
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Errors and warnings}
+%* *
+%************************************************************************
+
+\begin{code}
+warnDeprec :: (Name, DeprecTxt) -> RnM d ()
+warnDeprec (name, txt)
+ = pushSrcLocRn (getSrcLoc name) $
+ addWarnRn $
+ sep [ text (occNameFlavour (nameOccName name)) <+> ppr name <+>
+ text "is deprecated:", nest 4 (ppr txt) ]
+
+
+unusedFixityDecl rdr_name fixity
+ = hsep [ptext SLIT("Unused fixity declaration for"), quotes (ppr rdr_name)]
+
+dupFixityDecl rdr_name loc1 loc2
+ = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
+ ptext SLIT("at ") <+> ppr loc1,
+ ptext SLIT("and") <+> ppr loc2]
+\end{code}
+
+
+%********************************************************
+%* *
+\subsection{Checking usage information}
+%* *
+%********************************************************
+
+\begin{code}
+{-
+checkEarlyExit mod_name
+ = traceRn (text "Considering whether compilation is required...") `thenRn_`
+
+ -- Read the old interface file, if any, for the module being compiled
+ findAndReadIface doc_str mod_name False {- Not hi-boot -} `thenRn` \ maybe_iface ->
+
+ -- CHECK WHETHER WE HAVE IT ALREADY
+ case maybe_iface of
+ Left err -> -- Old interface file not found, so we'd better bail out
+ traceRn (vcat [ptext SLIT("No old interface file for") <+> ppr mod_name,
+ err]) `thenRn_`
+ returnRn (outOfDate, Nothing)
+
+ Right iface
+ | panic "checkEarlyExit: ???: not opt_SourceUnchanged"
+ -> -- Source code changed
+ traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_`
+ returnRn (False, Just iface)
+
+ | otherwise
+ -> -- Source code unchanged and no errors yet... carry on
+ checkModUsage (pi_usages iface) `thenRn` \ up_to_date ->
+ returnRn (up_to_date, Just iface)
+ where
+ -- Only look in current directory, with suffix .hi
+ doc_str = sep [ptext SLIT("need usage info from"), ppr mod_name]
\end{code}
+
+\begin{code}
+upToDate = True
+outOfDate = False
+
+checkModUsage :: [ImportVersion OccName] -> RnMG Bool
+-- 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 [] = returnRn upToDate -- Yes! Everything is up to date!
+
+checkModUsage ((mod_name, _, _, NothingAtAll) : rest)
+ -- 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.
+ = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_`
+ checkModUsage rest -- This one's ok, so check the rest
+
+checkModUsage ((mod_name, _, _, whats_imported) : rest)
+ = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, 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_mod_vers, new_fix_vers, new_rule_vers, _, _)
+ = case lookupFM (iImpModInfo ifaces) mod_name of
+ Just (_, _, Just stuff) -> stuff
+
+ old_mod_vers = case whats_imported of
+ Everything v -> v
+ Specifically v _ _ _ -> v
+ -- NothingAtAll case dealt with by previous eqn for checkModUsage
+ in
+ -- 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:"), ppr mod_name])
+ `thenRn_` checkModUsage rest
+ else
+ traceRn (sep [ptext SLIT("Module version has changed:"), ppr 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 { -- NothingAtAll dealt with earlier
+
+ Everything _
+ -> out_of_date (ptext SLIT("...and I needed the whole module")) ;
+
+ Specifically _ old_fix_vers old_rule_vers old_local_vers ->
+
+ if old_fix_vers /= new_fix_vers then
+ out_of_date (ptext SLIT("Fixities changed"))
+ else if old_rule_vers /= new_rule_vers then
+ out_of_date (ptext SLIT("Rules changed"))
+ else
+ -- 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 outOfDate -- This one failed, so just bail out now
+ }}
+ where
+ doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
+
+
+checkEntityUsage mod decls []
+ = returnRn upToDate -- Yes! All up to date!
+
+checkEntityUsage mod decls ((occ_name,old_vers) : rest)
+ = newGlobalName mod occ_name `thenRn` \ name ->
+ case lookupNameEnv decls 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
+ -- Up to date, so check the rest
+ -> checkEntityUsage mod decls rest
+
+ | otherwise
+ -- Out of date, so bale out
+ -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
+
+out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate
+-}
+\end{code}
+