X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Frename%2FRnEnv.lhs;h=825ed19fc230bc100e637db880a9da54459073a0;hb=edc0bafd3fcd01b85a2e8894e5dfe149eb0e0857;hp=9f6a96a4cd4d0fb6a8dfcbad1267ce409cf936dd;hpb=a6f2d598e1e7760d334d1b5ea0b7745e66835e11;p=ghc-hetmet.git

diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs
index 9f6a96a..825ed19 100644
--- a/compiler/rename/RnEnv.lhs
+++ b/compiler/rename/RnEnv.lhs
@@ -505,6 +505,8 @@ lookupQualifiedName rdr_name
     doc = ptext (sLit "Need to find") <+> ppr rdr_name
 \end{code}
 
+Note [Looking up signature names]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 lookupSigOccRn is used for type signatures and pragmas
 Is this valid?
   module A
@@ -525,10 +527,13 @@ return the imported 'f', so that later on the reanamer will
 correctly report "misplaced type sig".
 
 \begin{code}
-lookupSigOccRn :: Maybe NameSet	   -- Just ns => source file; these are the binders
+lookupSigOccRn :: Maybe NameSet	   -- Just ns => these are the binders
 				   -- 	 	 in the same group
-				   -- Nothing => hs-boot file; signatures without 
+				   -- Nothing => signatures without 
 				   -- 		 binders are expected
+				   --		 (a) top-level (SPECIALISE prags)
+				   -- 		 (b) class decls
+				   --		 (c) hs-boot files
 	       -> Sig RdrName
 	       -> Located RdrName -> RnM (Located Name)
 lookupSigOccRn mb_bound_names sig
@@ -538,29 +543,29 @@ lookupSigOccRn mb_bound_names sig
 	   Left err   -> do { addErr err; return (mkUnboundName rdr_name) }
 	   Right name -> return name }
 
-lookupBindGroupOcc :: Maybe NameSet  -- Just ns => source file; these are the binders
-				     -- 	 	 in the same group
-				     -- Nothing => hs-boot file; signatures without 
-				     -- 		 binders are expected
-	           -> SDoc
+lookupBindGroupOcc :: Maybe NameSet  -- See notes on the (Maybe NameSet)
+	           -> SDoc           --  in lookupSigOccRn
 	           -> RdrName -> RnM (Either Message Name)
 -- Looks up the RdrName, expecting it to resolve to one of the 
 -- bound names passed in.  If not, return an appropriate error message
+--
+-- See Note [Looking up signature names]
 lookupBindGroupOcc mb_bound_names what rdr_name
-  = do	{ local_env <- getLocalRdrEnv
-	; case lookupLocalRdrEnv local_env rdr_name of 
-  	    Just n  -> check_local_name n
-  	    Nothing -> do	-- Not defined in a nested scope
+  = do  { local_env <- getLocalRdrEnv
+        ; case lookupLocalRdrEnv local_env rdr_name of {
+            Just n  -> check_local_name n;
+            Nothing -> do       -- Not defined in a nested scope
 
         { env <- getGlobalRdrEnv 
-  	; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name)
-	; case (filter isLocalGRE gres) of
-	    (gre:_) -> check_local_name (gre_name gre)
-			-- If there is more than one local GRE for the 
-			-- same OccName, that will be reported separately
-	    [] | null gres -> bale_out_with empty
-	       | otherwise -> bale_out_with import_msg
-  	}}
+        ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name)
+        ; case (filter isLocalGRE gres) of
+            (gre:_) -> check_local_name (gre_name gre)
+                        -- If there is more than one local GRE for the 
+                        -- same OccName 'f', that will be reported separately
+                        -- as a duplicate top-level binding for 'f'
+            [] | null gres -> bale_out_with empty
+               | otherwise -> bale_out_with import_msg
+        }}}
     where
       check_local_name name 	-- The name is in scope, and not imported
   	  = case mb_bound_names of
@@ -725,7 +730,7 @@ lookupTyFixityRn (L _ n) = lookupFixityRn n
 %*									*
 			Rebindable names
 	Dealing with rebindable syntax is driven by the 
-	Opt_NoImplicitPrelude dynamic flag.
+	Opt_RebindableSyntax dynamic flag.
 
 	In "deriving" code we don't want to use rebindable syntax
 	so we switch off the flag locally
@@ -764,8 +769,8 @@ checks the type of the user thing against the type of the standard thing.
 lookupSyntaxName :: Name 				-- The standard name
 	         -> RnM (SyntaxExpr Name, FreeVars)	-- Possibly a non-standard name
 lookupSyntaxName std_name
-  = xoptM Opt_ImplicitPrelude		`thenM` \ implicit_prelude -> 
-    if implicit_prelude then normal_case
+  = xoptM Opt_RebindableSyntax		`thenM` \ rebindable_on -> 
+    if not rebindable_on then normal_case 
     else
 	-- Get the similarly named thing from the local environment
     lookupOccRn (mkRdrUnqual (nameOccName std_name)) `thenM` \ usr_name ->
@@ -776,8 +781,8 @@ lookupSyntaxName std_name
 lookupSyntaxTable :: [Name]				-- Standard names
 		  -> RnM (SyntaxTable Name, FreeVars)	-- See comments with HsExpr.ReboundNames
 lookupSyntaxTable std_names
-  = xoptM Opt_ImplicitPrelude		`thenM` \ implicit_prelude -> 
-    if implicit_prelude then normal_case 
+  = xoptM Opt_RebindableSyntax		`thenM` \ rebindable_on -> 
+    if not rebindable_on then normal_case 
     else
     	-- Get the similarly named thing from the local environment
     mapM (lookupOccRn . mkRdrUnqual . nameOccName) std_names 	`thenM` \ usr_names ->
@@ -1100,7 +1105,7 @@ addNameClashErrRn rdr_name names
     (np1:nps) = names
     msg1 = ptext  (sLit "either") <+> mk_ref np1
     msgs = [ptext (sLit "    or") <+> mk_ref np | np <- nps]
-    mk_ref gre = quotes (ppr (gre_name gre)) <> comma <+> pprNameProvenance gre
+    mk_ref gre = sep [quotes (ppr (gre_name gre)) <> comma, pprNameProvenance gre]
 
 shadowedNameWarn :: OccName -> [SDoc] -> SDoc
 shadowedNameWarn occ shadowed_locs