diff options
| -rw-r--r-- | compiler/basicTypes/Name.hs | 4 | ||||
| -rw-r--r-- | compiler/main/HscTypes.hs | 21 | ||||
| -rw-r--r-- | compiler/utils/Outputable.hs | 20 |
3 files changed, 31 insertions, 14 deletions
diff --git a/compiler/basicTypes/Name.hs b/compiler/basicTypes/Name.hs index ac2071f6b6..80b7cc84d9 100644 --- a/compiler/basicTypes/Name.hs +++ b/compiler/basicTypes/Name.hs @@ -534,8 +534,8 @@ pprModulePrefix sty mod occ = sdocWithDynFlags $ \dflags -> NameQual modname -> ppr modname <> dot -- Name is in scope NameNotInScope1 -> ppr mod <> dot -- Not in scope NameNotInScope2 -> ppr (modulePackageKey mod) <> colon -- Module not in - <> ppr (moduleName mod) <> dot -- scope either - _otherwise -> empty + <> ppr (moduleName mod) <> dot -- scope either + NameUnqual -> empty -- In scope unqualified ppr_underscore_unique :: Unique -> SDoc -- Print an underscore separating the name from its unique diff --git a/compiler/main/HscTypes.hs b/compiler/main/HscTypes.hs index 90ed55978f..92c57ba0e5 100644 --- a/compiler/main/HscTypes.hs +++ b/compiler/main/HscTypes.hs @@ -1524,11 +1524,26 @@ mkPrintUnqualified dflags env = QueryQualify qual_name (mkQualPackage dflags) where qual_name mod occ + | [] <- unqual_gres + , modulePackageKey mod `elem` [primPackageKey, basePackageKey, thPackageKey] + , not (isDerivedOccName occ) + = NameUnqual -- For names from ubiquitous packages that come with GHC, if + -- there are no entities called unqualified 'occ', then + -- print unqualified. Doing so does not cause ambiguity, + -- and it reduces the amount of qualification in error + -- messages. We can't do this for all packages, because we + -- might get errors like "Can't unify T with T". But the + -- ubiquitous packages don't contain any such gratuitous + -- name clashes. + -- + -- A motivating example is 'Constraint'. It's often not in + -- scope, but printing GHC.Prim.Constraint seems overkill. + | [gre] <- unqual_gres , right_name gre - = NameUnqual - -- If there's a unique entity that's in scope unqualified with 'occ' - -- AND that entity is the right one, then we can use the unqualified name + = NameUnqual -- If there's a unique entity that's in scope + -- unqualified with 'occ' AND that entity is + -- the right one, then we can use the unqualified name | [gre] <- qual_gres = NameQual (get_qual_mod (gre_prov gre)) diff --git a/compiler/utils/Outputable.hs b/compiler/utils/Outputable.hs index e6e8e02dda..36ac6271be 100644 --- a/compiler/utils/Outputable.hs +++ b/compiler/utils/Outputable.hs @@ -173,15 +173,17 @@ type QueryQualifyModule = Module -> Bool type QueryQualifyPackage = PackageKey -> Bool -- See Note [Printing original names] in HscTypes -data QualifyName -- given P:M.T - = NameUnqual -- refer to it as "T" - | NameQual ModuleName -- refer to it as "X.T" for the supplied X - | NameNotInScope1 - -- it is not in scope at all, but M.T is not bound in the current - -- scope, so we can refer to it as "M.T" - | NameNotInScope2 - -- it is not in scope at all, and M.T is already bound in the - -- current scope, so we must refer to it as "P:M.T" +data QualifyName -- Given P:M.T + = NameUnqual -- It's in scope unqualified as "T" + -- OR nothing called "T" is in scope + + | NameQual ModuleName -- It's in scope qualified as "X.T" + + | NameNotInScope1 -- It's not in scope at all, but M.T is not bound + -- in the current scope, so we can refer to it as "M.T" + + | NameNotInScope2 -- It's not in scope at all, and M.T is already bound in + -- the current scope, so we must refer to it as "P:M.T" reallyAlwaysQualifyNames :: QueryQualifyName reallyAlwaysQualifyNames _ _ = NameNotInScope2 |