Commit adc9d5cc authored by simonpj's avatar simonpj
Browse files

[project @ 2005-06-29 15:41:27 by simonpj]

MERGE TO STABLE

Fix a long-lurking renamer bug, concerning the reporting of ambiguous
name occurrences.

	(the merge may require a little fiddling)
parent 1fb91a52
......@@ -52,6 +52,7 @@ import OccName ( NameSpace, varName,
import Module ( Module, mkModuleFS )
import Name ( Name, NamedThing(getName), nameModule, nameParent_maybe,
nameOccName, isExternalName, nameSrcLoc )
import Maybes ( mapCatMaybes )
import SrcLoc ( isGoodSrcLoc, SrcSpan )
import Outputable
import Util ( thenCmp )
......@@ -353,13 +354,9 @@ extendGlobalRdrEnv env gre = extendOccEnv_C add env occ [gre]
lookupGRE_RdrName :: RdrName -> GlobalRdrEnv -> [GlobalRdrElt]
lookupGRE_RdrName rdr_name env
= case lookupOccEnv env occ of
Nothing -> []
Just gres | isUnqual rdr_name -> filter unQualOK gres
| otherwise -> filter (hasQual mod) gres
where
mod = rdrNameModule rdr_name
occ = rdrNameOcc rdr_name
= case lookupOccEnv env (rdrNameOcc rdr_name) of
Nothing -> []
Just gres -> pickGREs rdr_name gres
lookupGRE_Name :: GlobalRdrEnv -> Name -> [GlobalRdrElt]
lookupGRE_Name env name
......@@ -367,6 +364,42 @@ lookupGRE_Name env name
gre_name gre == name ]
pickGREs :: RdrName -> [GlobalRdrElt] -> [GlobalRdrElt]
-- Take a list of GREs which have the right OccName
-- Pick those GREs that are suitable for this RdrName
-- And for those, keep only only the Provenances that are suitable
--
-- Consider
-- module A ( f ) where
-- import qualified Foo( f )
-- import Baz( f )
-- f = undefined
-- Let's suppose that Foo.f and Baz.f are the same entity really.
-- The export of f is ambiguous because it's in scope from the local def
-- and the import. The lookup of (Unqual f) should return a GRE for
-- the locally-defined f, and a GRE for the imported f, with a *single*
-- provenance, namely the one for Baz(f).
pickGREs rdr_name gres
= mapCatMaybes pick gres
where
is_unqual = isUnqual rdr_name
mod = rdrNameModule rdr_name
pick :: GlobalRdrElt -> Maybe GlobalRdrElt
pick gre@(GRE {gre_prov = LocalDef m}) -- Local def
| is_unqual || m == mod = Just gre
| otherwise = Nothing
pick gre@(GRE {gre_prov = Imported [is]}) -- Single import (efficiency)
| is_unqual && not (is_qual (is_decl is)) = Just gre
| mod == is_as (is_decl is) = Just gre
| otherwise = Nothing
pick gre@(GRE {gre_prov = Imported is}) -- Multiple import
| null filtered_is = Nothing
| otherwise = Just (gre {gre_prov = Imported filtered_is})
where
filtered_is | is_unqual = filter (not . is_qual . is_decl) is
| otherwise = filter ((== mod) . is_as . is_decl) is
isLocalGRE :: GlobalRdrElt -> Bool
isLocalGRE (GRE {gre_prov = LocalDef _}) = True
isLocalGRE other = False
......@@ -376,11 +409,6 @@ unQualOK :: GlobalRdrElt -> Bool
unQualOK (GRE {gre_prov = LocalDef _}) = True
unQualOK (GRE {gre_prov = Imported is}) = not (all (is_qual . is_decl) is)
hasQual :: Module -> GlobalRdrElt -> Bool
-- A qualified version of this thing is in scope
hasQual mod (GRE {gre_prov = LocalDef m}) = m == mod
hasQual mod (GRE {gre_prov = Imported is}) = any ((== mod) . is_as . is_decl) is
plusGlobalRdrEnv :: GlobalRdrEnv -> GlobalRdrEnv -> GlobalRdrEnv
plusGlobalRdrEnv env1 env2 = plusOccEnv_C (foldr insertGRE) env1 env2
......@@ -503,6 +531,7 @@ plusProv p1 p2@(LocalDef _) = p2
plusProv (Imported is1) (Imported is2) = Imported (is1++is2)
pprNameProvenance :: GlobalRdrElt -> SDoc
-- Print out the place where the name was imported
pprNameProvenance (GRE {gre_name = name, gre_prov = LocalDef _})
= ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
pprNameProvenance (GRE {gre_name = name, gre_prov = Imported (why:whys)})
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment