\begin{code}
module RnNames (
rnImports, importsFromLocalDecls,
+ getLocalDeclBinders, extendRdrEnvRn,
reportUnusedNames, reportDeprecations,
- mkModDeps, exportsToAvails, exportsFromAvail
+ mkModDeps, exportsFromAvail
) where
#include "HsVersions.h"
Sig(..), collectGroupBinders, tyClDeclNames
)
import RnEnv
-import IfaceEnv ( lookupAvail )
+import IfaceEnv ( ifaceExportNames )
import LoadIface ( loadSrcInterface )
import TcRnMonad
import OccName ( srcDataName, isTcOcc, occNameFlavour, OccEnv,
mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv )
import HscTypes ( GenAvailInfo(..), AvailInfo,
- IfaceExport, HomePackageTable, PackageIfaceTable,
- availNames, unQualInScope,
+ HomePackageTable, PackageIfaceTable,
+ unQualInScope,
Deprecs(..), ModIface(..), Dependencies(..),
lookupIface, ExternalPackageState(..)
)
import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace,
GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts,
- unQualOK, lookupGRE_Name,
+ extendGlobalRdrEnv, lookupGlobalRdrEnv, unQualOK, lookupGRE_Name,
Provenance(..), ImportSpec(..),
isLocalGRE, pprNameProvenance )
import Outputable
import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe, orElse )
import SrcLoc ( Located(..), mkGeneralSrcSpan,
- unLoc, noLoc, srcLocSpan, combineSrcSpans, SrcSpan )
+ unLoc, noLoc, srcLocSpan, SrcSpan )
import BasicTypes ( DeprecTxt )
-import ListSetOps ( removeDups )
-import Util ( sortLe, notNull, isSingleton )
+import DriverPhases ( isHsBoot )
+import Util ( notNull )
import List ( partition )
import IO ( openFile, IOMode(..) )
\end{code}
Nothing -> imp_mod_name
Just another_name -> another_name
imp_spec = ImportSpec { is_mod = imp_mod_name, is_qual = qual_only,
- is_loc = loc, is_as = qual_mod_name }
+ is_loc = loc, is_as = qual_mod_name, is_explicit = False }
in
-- Get the total imports, and filter them according to the import list
- exportsToAvails filtered_exports `thenM` \ total_avails ->
+ ifaceExportNames filtered_exports `thenM` \ total_avails ->
filterImports iface imp_spec
imp_details total_avails `thenM` \ (avail_env, gbl_env) ->
returnM (gbl_env, imports)
-exportsToAvails :: [IfaceExport] -> TcRnIf gbl lcl NameSet
-exportsToAvails exports
- = foldlM do_one emptyNameSet exports
- where
- do_one acc (mod, exports) = foldlM (do_avail mod) acc exports
- do_avail mod acc avail = do { ns <- lookupAvail mod avail
- ; return (addListToNameSet acc ns) }
-
warnRedundantSourceImport mod_name
= ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
<+> quotes (ppr mod_name)
Complain about duplicate bindings
\begin{code}
-importsFromLocalDecls :: HsGroup RdrName
- -> RnM (GlobalRdrEnv, ImportAvails)
+importsFromLocalDecls :: HsGroup RdrName -> RnM TcGblEnv
importsFromLocalDecls group
- = getModule `thenM` \ this_mod ->
- getLocalDeclBinders this_mod group `thenM` \ avails ->
- -- The avails that are returned don't include the "system" names
- let
- all_names :: [Name] -- All the defns; no dups eliminated
- all_names = [name | avail <- avails, name <- availNames avail]
+ = do { gbl_env <- getGblEnv
- dups :: [[Name]]
- (_, dups) = removeDups compare all_names
- in
- -- Check for duplicate definitions
- -- The complaint will come out as "Multiple declarations of Foo.f" because
- -- since 'f' is in the env twice, the unQualInScope used by the error-msg
- -- printer returns False. It seems awkward to fix, unfortunately.
- mappM_ addDupDeclErr dups `thenM_`
-
- doptM Opt_ImplicitPrelude `thenM` \ implicit_prelude ->
- let
- prov = LocalDef this_mod
- gbl_env = mkGlobalRdrEnv gres
- gres = [ GRE { gre_name = name, gre_prov = prov}
- | name <- all_names]
+ ; names <- getLocalDeclBinders gbl_env group
+ ; implicit_prelude <- doptM Opt_ImplicitPrelude
+ ; let {
-- Optimisation: filter out names for built-in syntax
-- They just clutter up the environment (esp tuples), and the parser
-- will generate Exact RdrNames for them, so the cluttered
-- Ditto in fixity decls; e.g. infix 5 :
-- Sigh. It doesn't matter because it only affects the Data.Tuple really.
-- The important thing is to trim down the exports.
- filtered_names
- | implicit_prelude = all_names
- | otherwise = filter (not . isBuiltInSyntax) all_names
+ filtered_names
+ | implicit_prelude = names
+ | otherwise = filter (not . isBuiltInSyntax) names ;
- imports = emptyImportAvails {
- imp_env = unitModuleEnv this_mod $
+ ; this_mod = tcg_mod gbl_env
+ ; imports = emptyImportAvails {
+ imp_env = unitModuleEnv this_mod $
mkNameSet filtered_names
- }
- in
- returnM (gbl_env, imports)
-\end{code}
+ }
+ }
+ ; rdr_env' <- extendRdrEnvRn this_mod (tcg_rdr_env gbl_env) names
-%*********************************************************
-%* *
-\subsection{Getting binders out of a declaration}
-%* *
-%*********************************************************
+ ; returnM (gbl_env { tcg_rdr_env = rdr_env',
+ tcg_imports = imports `plusImportAvails` tcg_imports gbl_env })
+ }
+
+extendRdrEnvRn :: Module -> GlobalRdrEnv -> [Name] -> RnM GlobalRdrEnv
+-- Add the new locally-bound names one by one, checking for duplicates as
+-- we do so. Remember that in Template Haskell the duplicates
+-- might *already be* in the GlobalRdrEnv from higher up the module
+extendRdrEnvRn mod rdr_env names
+ = foldlM add_local rdr_env names
+ where
+ add_local rdr_env name
+ | gres <- lookupGlobalRdrEnv rdr_env (nameOccName name)
+ , (dup_gre:_) <- filter isLocalGRE gres -- Check for existing *local* defns
+ = do { addDupDeclErr (gre_name dup_gre) name
+ ; return rdr_env }
+ | otherwise
+ = return (extendGlobalRdrEnv rdr_env new_gre)
+ where
+ new_gre = GRE {gre_name = name, gre_prov = prov}
+
+ prov = LocalDef mod
+\end{code}
@getLocalDeclBinders@ returns the names for an @HsDecl@. It's
used for source code.
*** See "THE NAMING STORY" in HsDecls ****
\begin{code}
-getLocalDeclBinders :: Module -> HsGroup RdrName -> RnM [AvailInfo]
-getLocalDeclBinders mod (HsGroup {hs_valds = val_decls,
- hs_tyclds = tycl_decls,
- hs_fords = foreign_decls })
- = -- For type and class decls, we generate Global names, with
- -- no export indicator. They need to be global because they get
- -- permanently bound into the TyCons and Classes. They don't need
- -- an export indicator because they are all implicitly exported.
-
- mappM new_tc tycl_decls `thenM` \ tc_avails ->
-
+getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [Name]
+getLocalDeclBinders gbl_env (HsGroup {hs_valds = val_decls,
+ hs_tyclds = tycl_decls,
+ hs_fords = foreign_decls })
+ = do { tc_names_s <- mappM new_tc tycl_decls
+ ; val_names <- mappM new_simple val_bndrs
+ ; return (foldr (++) val_names tc_names_s) }
+ where
+ mod = tcg_mod gbl_env
+ is_hs_boot = isHsBoot (tcg_src gbl_env) ;
+ val_bndrs | is_hs_boot = sig_hs_bndrs
+ | otherwise = for_hs_bndrs ++ val_hs_bndrs
-- In a hs-boot file, the value binders come from the
-- *signatures*, and there should be no foreign binders
- tcIsHsBoot `thenM` \ is_hs_boot ->
- let val_bndrs | is_hs_boot = sig_hs_bndrs
- | otherwise = for_hs_bndrs ++ val_hs_bndrs
- in
- mappM new_simple val_bndrs `thenM` \ names ->
- returnM (tc_avails ++ map Avail names)
- where
new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name
sig_hs_bndrs = [nm | HsBindGroup _ lsigs _ <- val_decls,
for_hs_bndrs = [nm | L _ (ForeignImport nm _ _ _) <- foreign_decls]
new_tc tc_decl
- = newTopSrcBinder mod Nothing main_rdr `thenM` \ main_name ->
- mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs `thenM` \ sub_names ->
- returnM (AvailTC main_name (main_name : sub_names))
+ = do { main_name <- newTopSrcBinder mod Nothing main_rdr
+ ; sub_names <- mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs
+ ; return (main_name : sub_names) }
where
(main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
\end{code}
-- Warns/informs if import spec contains duplicates.
mkGenericRdrEnv imp_spec names
- = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] False }
+ = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] }
| name <- nameSetToList names ]
filterImports iface imp_spec Nothing all_names
; returnM (map (mk_gre loc) names) }
where
mk_gre loc name = GRE { gre_name = name,
- gre_prov = Imported [this_imp_spec loc] (explicit name) }
- this_imp_spec loc = imp_spec { is_loc = loc }
- explicit name = all_explicit || isNothing (nameParent_maybe name)
+ gre_prov = Imported [imp_spec'] }
+ where
+ imp_spec' = imp_spec { is_loc = loc, is_explicit = explicit }
+ explicit = all_explicit || isNothing (nameParent_maybe name)
get_item :: IE RdrName -> RnM [GlobalRdrElt]
-- Empty result for a bad item.
where
env = mkOccEnv [(nameOccName s, s) | s <- subNames subs n]
mb_names = map (lookupOccEnv env . rdrNameOcc) rdrs
+filterAvail (IEModuleContents _) _ _ = panic "filterAvail"
subNames :: NameEnv [Name] -> Name -> [Name]
subNames env n = lookupNameEnv env n `orElse` []
used_names = findUses (tcg_dus tcg_env) emptyNameSet
all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env)
- check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_) _})
+ check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_)})
| name `elemNameSet` used_names
, Just deprec_txt <- lookupDeprec hpt pit name
= setSrcSpan (is_loc imp_spec) $
= do { warnUnusedTopBinds unused_locals
; warnUnusedModules unused_imp_mods
; warnUnusedImports unused_imports
- ; warnDuplicateImports dup_imps
+ ; warnDuplicateImports defined_and_used
; printMinimalImports minimal_imports }
where
used_names, all_used_names :: NameSet
(defined_and_used, defined_but_not_used)
= partition (gre_is_used all_used_names) defined_names
- -- Find the duplicate imports
- dup_imps = filter is_dup defined_and_used
- is_dup (GRE {gre_prov = Imported imp_spec True}) = not (isSingleton imp_spec)
- is_dup other = False
-
-- Filter out the ones that are
-- (a) defined in this module, and
-- (b) not defined by a 'deriving' clause
unused_imports :: [GlobalRdrElt]
unused_imports = filter unused_imp defined_but_not_used
- unused_imp (GRE {gre_prov = Imported imp_specs True})
+ unused_imp (GRE {gre_prov = Imported imp_specs})
= not (all (module_unused . is_mod) imp_specs)
+ && any is_explicit imp_specs
-- Don't complain about unused imports if we've already said the
-- entire import is unused
unused_imp other = False
-- We've carefully preserved the provenance so that we can
-- construct minimal imports that import the name by (one of)
-- the same route(s) as the programmer originally did.
- add_name (GRE {gre_name = n, gre_prov = Imported imp_specs _}) acc
+ add_name (GRE {gre_name = n, gre_prov = Imported imp_specs}) acc
= addToFM_C plusAvailEnv acc (is_mod (head imp_specs))
(unitAvailEnv (mk_avail n (nameParent_maybe n)))
add_name other acc
---------------------
warnDuplicateImports :: [GlobalRdrElt] -> RnM ()
+-- Given the GREs for names that are used, figure out which imports
+-- could be omitted without changing the top-level environment.
+--
+-- NB: Given import Foo( T )
+-- import qualified Foo
+-- we do not report a duplicate import, even though Foo.T is brought
+-- into scope by both, because there's nothing you can *omit* without
+-- changing the top-level environment. So we complain only if it's
+-- explicitly named in both imports or neither.
+--
+-- Furthermore, we complain about Foo.T only if
+-- there is no complaint about (unqualified) T
+
warnDuplicateImports gres
- = ifOptM Opt_WarnUnusedImports (mapM_ warn gres)
+ = ifOptM Opt_WarnUnusedImports $
+ sequenceM_ [ warn name pr
+ -- The 'head' picks the first offending group
+ -- for this particular name
+ | GRE { gre_name = name, gre_prov = Imported imps } <- gres
+ , pr <- redundants imps ]
where
- warn (GRE { gre_name = name, gre_prov = Imported imps _ })
- = addWarn ((quotes (ppr name) <+> ptext SLIT("is imported more than once:"))
- $$ nest 2 (vcat (map ppr imps)))
-
+ warn name (red_imp, cov_imp)
+ = addWarnAt (is_loc red_imp)
+ (vcat [ptext SLIT("Redundant import of:") <+> quotes pp_name,
+ ptext SLIT("It is also") <+> ppr cov_imp])
+ where
+ pp_name | is_qual red_imp = ppr (is_as red_imp) <> dot <> ppr occ
+ | otherwise = ppr occ
+ occ = nameOccName name
+
+ redundants :: [ImportSpec] -> [(ImportSpec,ImportSpec)]
+ -- The returned pair is (redundant-import, covering-import)
+ redundants imps
+ = [ (red_imp, cov_imp)
+ | red_imp <- imps
+ , cov_imp <- take 1 (filter (covers red_imp) imps) ]
+
+ -- "red_imp" is a putative redundant import
+ -- "cov_imp" potentially covers it
+ -- This test decides
+ covers red_imp cov_imp
+ | red_loc == cov_loc
+ = False -- Ignore diagonal elements
+ | not (is_as red_imp == is_as cov_imp)
+ = False -- They bring into scope different qualified names
+ | not (is_qual red_imp) && is_qual cov_imp
+ = False -- Covering one doesn't bring unqualified name into scope
+ | is_explicit red_imp
+ = not cov_explicit -- Redundant one is explicit and covering one isn't
+ || red_later -- Both are explicit; tie-break using red_later
+ | otherwise
+ = not cov_explicit -- Neither import is explicit
+ && (is_mod red_imp == is_mod cov_imp) -- They import the same module
+ && red_later -- Tie-break
+ where
+ cov_explicit = is_explicit cov_imp
+ red_loc = is_loc red_imp
+ cov_loc = is_loc cov_imp
+ red_later = red_loc > cov_loc
-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
printMinimalImports :: FiniteMap Module AvailEnv -- Minimal imports
(gre:_) -> gre
[] -> pprPanic "exportClashErr" (ppr name)
-addDupDeclErr :: [Name] -> TcRn ()
-addDupDeclErr names
- = addErrAt big_loc $
+addDupDeclErr :: Name -> Name -> TcRn ()
+addDupDeclErr name1 name2
+ = addErrAt (srcLocSpan loc2) $
vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr name1),
- ptext SLIT("Declared at:") <+> vcat (map ppr sorted_locs)]
+ ptext SLIT("Declared at:") <+> vcat [ppr (nameSrcLoc name1), ppr loc2]]
where
- locs = map nameSrcLoc names
- big_loc = foldr1 combineSrcSpans (map srcLocSpan locs)
- name1 = head names
- sorted_locs = sortLe (<=) (sortLe (<=) locs)
+ loc2 = nameSrcLoc name2
dupExportWarn occ_name ie1 ie2
= hsep [quotes (ppr occ_name),
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