FIX #1465, error messages could sometimes say things like "A.T doesn't match A.T"

[ghc-hetmet.git] / compiler / basicTypes / Name.lhs

diff --git a/compiler/basicTypes/Name.lhs b/compiler/basicTypes/Name.lhs
index 6fccb7f..488dbca 100644 (file)
--- a/compiler/basicTypes/Name.lhs
+++ b/compiler/basicTypes/Name.lhs
@@ -9,7 +9,7 @@
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
 -- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
 module Name (
@@ -367,9 +367,13 @@ pprExternal sty uniq mod occ is_wired is_builtin
                                 pprUnique uniq])
   | BuiltInSyntax <- is_builtin  = ppr_occ_name occ
        -- never qualify builtin syntax
-  | Just mod <- qualName sty mod occ = ppr mod <> dot <> ppr_occ_name occ
-        -- the PrintUnqualified tells us how to qualify this Name, if at all
+  | NameQual modname <- qual_name = ppr modname <> dot <> ppr_occ_name occ
+        -- see HscTypes.mkPrintUnqualified and Outputable.QualifyName:
+  | NameNotInScope1 <- qual_name  = ppr mod <> dot <> ppr_occ_name occ
+  | NameNotInScope2 <- qual_name  = ppr (modulePackageId mod) <> char ':' <>
+                                    ppr (moduleName mod) <> dot <> ppr_occ_name occ
   | otherwise                    = ppr_occ_name occ
+  where qual_name = qualName sty mod occ
 
 pprInternal sty uniq occ
   | codeStyle sty  = pprUnique uniq