[project @ 2000-07-07 12:13:22 by simonpj]

Improve comments

diff --git a/ghc/compiler/rename/Rename.lhs b/ghc/compiler/rename/Rename.lhs
index 73df99f..1a9cc0b 100644 (file)
--- a/ghc/compiler/rename/Rename.lhs
+++ b/ghc/compiler/rename/Rename.lhs
@@ -712,12 +712,19 @@ reportUnusedNames mod_name direct_import_mods
        -- inst_mods are directly-imported modules that 
        --      contain instance decl(s) that the renamer decided to suck in
        -- It's not necessarily redundant to import such modules.
-       -- NOTE: import M () is not necessarily redundant, even if
+       --
+       -- NOTE: Consider 
+       --            module This
+       --              import M ()
+       --
+       --       The import M() is not *necessarily* redundant, even if
        --       we suck in no instance decls from M (e.g. it contains 
-       --       no instance decls).  It may be that we import M solely to
-       --       ensure that M's orphan instance decls (or those in its imports)
-       --       are visible to people who import this module.  Sigh. There's
-       --       really no good way to detect this, so the error message is weakened
+       --       no instance decls, or This contains no code).  It may be 
+       --       that we import M solely to ensure that M's orphan instance 
+       --       decls (or those in its imports) are visible to people who 
+       --       import This.  Sigh. 
+       --       There's really no good way to detect this, so the error message 
+       --       in RnEnv.warnUnusedModules is weakened instead
        inst_mods = [m | InstD (InstDecl _ _ _ dfun _) <- imported_decls,
                         let m = moduleName (nameModule dfun),
                         m `elem` direct_import_mods