-- for details
module RnNames (
- rnImports, importsFromLocalDecls,
- rnExports,
- getLocalDeclBinders, extendRdrEnvRn,
+ rnImports, getLocalNonValBinders,
+ rnExports, extendGlobalRdrEnvRn,
reportUnusedNames, finishDeprecations,
) where
import Module
import Name
import NameEnv
-import UniqFM
+import LazyUniqFM
import NameSet
import OccName
import HscTypes
import BasicTypes ( DeprecTxt, Fixity )
import DriverPhases ( isHsBoot )
import Util
+import FastString
import ListSetOps
import Data.List ( partition, concatMap, (\\), delete )
import IO ( openFile, IOMode(..) )
* the ImportAvails
created by its bindings.
-\begin{code}
--- Bool determines shadowing:
--- true: names in the group should shadow other UnQuals
--- with the same OccName (used in Template Haskell)
--- false: duplicates should be reported as an error
---
--- The UniqFM (OccName -> FixItem) associates a Name's OccName's
--- FastString with a fixity declaration (that needs the actual OccName
--- to be plugged in). This fixity must be brought into scope when such
--- a Name is.
-importsFromLocalDecls :: Bool -> HsGroup RdrName -> UniqFM (Located Fixity) -> RnM TcGblEnv
-importsFromLocalDecls shadowP group fixities
- = do { gbl_env <- getGblEnv
-
- ; avails <- getLocalDeclBinders gbl_env group
+Note [Shadowing in extendGlobalRdrEnvRn]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Usually when etending the GlobalRdrEnv we complain if a new binding
+duplicates an existing one. By adding the bindings one at a time,
+this check also complains if we add two new bindings for the same name.
+(Remember that in Template Haskell the duplicates might *already be*
+in the GlobalRdrEnv from higher up the module.)
+
+But with a Template Haskell quotation we want to *shadow*:
+ f x = h [d| f = 3 |]
+Here the inner binding for 'f' simply shadows the outer one.
+And that applies even if the binding for 'f' is in a where-clause,
+and hence is in the *local* RdrEnv not the *global* RdrEnv.
+
+Hence the shadowP boolean passed in.
- ; (rdr_env', fix_env') <- extendRdrEnvRn shadowP (tcg_rdr_env gbl_env,
- tcg_fix_env gbl_env)
- avails fixities
+\begin{code}
+extendGlobalRdrEnvRn :: Bool -- Note [Shadowing in extendGlobalRdrEnvRn]
+ -> [AvailInfo]
+ -> MiniFixityEnv
+ -> RnM (TcGblEnv, TcLclEnv)
+ -- Updates both the GlobalRdrEnv and the FixityEnv
+ -- We return a new TcLclEnv only becuase we might have to
+ -- delete some bindings from it; see Note [Shadowing in extendGlobalRdrEnvRn]
+
+extendGlobalRdrEnvRn shadowP avails new_fixities
+ = do { (gbl_env, lcl_env) <- getEnvs
+ ; let rdr_env = tcg_rdr_env gbl_env
+ fix_env = tcg_fix_env gbl_env
+
+ -- Delete new_occs from global and local envs
+ -- We are going to shadow them
+ -- See Note [Shadowing in extendGlobalRdrEnvRn]
+ new_occs = map (nameOccName . gre_name) gres
+ rdr_env1 = hideSomeUnquals rdr_env new_occs
+ lcl_env1 = lcl_env { tcl_rdr = delListFromOccEnv (tcl_rdr lcl_env) new_occs }
+
+ -- Note [Shadowing in extendGlobalRdrEnvRn]
+ (rdr_env2, lcl_env2) | shadowP = (rdr_env1, lcl_env1)
+ | otherwise = (rdr_env, lcl_env)
- ; traceRn (text "local avails: " <> ppr avails)
+ ; (rdr_env', fix_env') <- foldlM extend (rdr_env2, fix_env) gres
+
+ ; let gbl_env' = gbl_env { tcg_rdr_env = rdr_env', tcg_fix_env = fix_env' }
+ ; traceRn (text "extendGlobalRdrEnvRn" <+> (ppr new_fixities $$ ppr fix_env $$ ppr fix_env'))
+ ; return (gbl_env', lcl_env2) }
+ where
+ gres = gresFromAvails LocalDef avails
- ; return (gbl_env { tcg_rdr_env = rdr_env',
- tcg_fix_env = fix_env'})
- }
+ extend envs@(cur_rdr_env, cur_fix_env) gre
+ = let gres = lookupGlobalRdrEnv cur_rdr_env (nameOccName (gre_name gre))
+ in case filter isLocalGRE gres of -- Check for existing *local* defns
+ dup_gre:_ -> do { addDupDeclErr (gre_name dup_gre) (gre_name gre)
+ ; return envs }
+ [] -> return (simple_extend envs gre)
--- Bool determines shadowing as in importsFromLocalDecls.
--- UniqFM FixItem is the same as in importsFromLocalDecls.
---
--- 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.
---
--- Also update the FixityEnv with the fixities for the names brought into scope.
---
--- Note that the return values are the extensions of the two inputs,
--- not the extras relative to them.
-extendRdrEnvRn :: Bool -> (GlobalRdrEnv, NameEnv FixItem)
- -> [AvailInfo] -> UniqFM (Located Fixity) -> RnM (GlobalRdrEnv, NameEnv FixItem)
-extendRdrEnvRn shadowP (rdr_env, fix_env) avails fixities =
- let -- if there is a fixity decl for the gre,
- -- add it to the fixity env
- extendFixEnv env gre =
- let name = gre_name gre
- occ = nameOccName name
- curKey = occNameFS occ in
- case lookupUFM fixities curKey of
- Nothing -> env
- Just (L _ fi) -> extendNameEnv env name (FixItem occ fi)
-
- (rdr_env_to_extend, extender) =
- if shadowP
- then -- when shadowing is on,
- -- (1) we need to remove the existing Unquals for the
- -- names we're extending the env with
- -- (2) but extending the env is simple
- let names = concatMap availNames avails
- new_occs = map nameOccName names
- trimmed_rdr_env = hideSomeUnquals rdr_env new_occs
- in
- (trimmed_rdr_env,
- \(cur_rdr_env, cur_fix_env) -> \gre ->
- return (extendGlobalRdrEnv cur_rdr_env gre,
- extendFixEnv cur_fix_env gre))
- else -- when shadowing is off,
- -- (1) we don't munge the incoming env
- -- (2) but we need to check for dups when extending
- (rdr_env,
- \(cur_rdr_env, cur_fix_env) -> \gre ->
- let gres = lookupGlobalRdrEnv cur_rdr_env (nameOccName (gre_name gre))
- in case filter isLocalGRE gres of -- Check for existing *local* defns
- dup_gre:_ -> do { addDupDeclErr (gre_name dup_gre) (gre_name gre)
- ; return (cur_rdr_env, cur_fix_env) }
- [] -> return (extendGlobalRdrEnv cur_rdr_env gre,
- extendFixEnv cur_fix_env gre))
- in foldlM extender (rdr_env_to_extend, fix_env) (gresFromAvails LocalDef avails)
+ simple_extend (rdr_env, fix_env) gre
+ = (extendGlobalRdrEnv rdr_env gre, fix_env')
+ where
+ -- If there is a fixity decl for the gre, add it to the fixity env
+ name = gre_name gre
+ occ = nameOccName name
+ fix_env' = case lookupFsEnv new_fixities (occNameFS occ) of
+ Nothing -> fix_env
+ Just (L _ fi) -> extendNameEnv fix_env name (FixItem occ fi)
\end{code}
@getLocalDeclBinders@ returns the names for an @HsDecl@. It's
don't return it in the 'AvailInfo'.
\begin{code}
--- Note: this function does NOT get the binders of the ValBinds that
--- will be bound during renaming
-getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [AvailInfo]
-getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs,
- hs_tyclds = tycl_decls,
- hs_instds = inst_decls,
- hs_fords = foreign_decls })
+getLocalNonValBinders :: HsGroup RdrName -> RnM [AvailInfo]
+-- Get all the top-level binders bound the group *except*
+-- for value bindings, which are treated separately
+-- Specificaly we return AvailInfo for
+-- type decls
+-- class decls
+-- associated types
+-- foreign imports
+-- (in hs-boot files) value signatures
+
+getLocalNonValBinders group
+ = do { gbl_env <- getGblEnv
+ ; get_local_binders gbl_env group }
+
+get_local_binders gbl_env (HsGroup {hs_valds = ValBindsIn _ val_sigs,
+ hs_tyclds = tycl_decls,
+ hs_instds = inst_decls,
+ hs_fords = foreign_decls })
= do { tc_names_s <- mapM new_tc tycl_decls
; at_names_s <- mapM inst_ats inst_decls
; val_names <- mapM new_simple val_bndrs
--
-- NOTE: currently the test does not warn about
-- import M( x )
- -- imoprt N( x )
+ -- import N( x )
-- even if the same underlying 'x' is involved, because dropping
-- either import would change the qualified names in scope (M.x, N.x)
-- But if the qualified names aren't used, the import is indeed redundant