c-decl.c (merge_decls): Kill different_binding_level and different_tu arguments; simplify throughout.

	* c-decl.c (merge_decls): Kill different_binding_level and
	different_tu arguments; simplify throughout.
	(duplicate_decls): Likewise.
	(pushdecl, merge_translation_unit_decls): Update calls to
	duplicate_decls.
testsuite:
	* gcc.dg/noncompile/20020213-1.c: Add another dg-warning line.

From-SVN: r76269

1 files changed, 24 insertions, 83 deletions

diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index 93360be..9316c62 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -1252,23 +1252,15 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
 
 /* Subroutine of duplicate_decls.  NEWDECL has been found to be
    consistent with OLDDECL, but carries new information.  Merge the
-   new information into OLDDECL.  If DIFFERENT_BINDING_LEVEL or
-   DIFFERENT_TU is true, avoid completely merging the decls, as this
-   will break assumptions elsewhere.  This function issues no
+   new information into OLDDECL.  This function issues no
    diagnostics.  */
 
 static void
-merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
-	     bool different_binding_level, bool different_tu)
+merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
 {
   int new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL
 			   && DECL_INITIAL (newdecl) != 0);
 
-  /* When copying info to olddecl, we store into write_olddecl
-     instead.  This allows us to avoid modifying olddecl when
-     different_binding_level is true.  */
-  tree write_olddecl = different_binding_level ? newdecl : olddecl;
-
   /* For real parm decl following a forward decl, return 1 so old decl
      will be reused.  Only allow this to happen once.  */
   if (TREE_CODE (newdecl) == PARM_DECL
@@ -1282,25 +1274,9 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
     = (*targetm.merge_decl_attributes) (olddecl, newdecl);
 
   /* Merge the data types specified in the two decls.  */
-  if (TREE_CODE (newdecl) != FUNCTION_DECL || !DECL_BUILT_IN (olddecl))
-    {
-      if (different_binding_level)
-	{
-	  if (TYPE_ARG_TYPES (oldtype) != 0
-	      && TYPE_ARG_TYPES (newtype) == 0)
-	    TREE_TYPE (newdecl) = common_type (newtype, oldtype);
-	  else
-	    TREE_TYPE (newdecl)
-	      = build_type_attribute_variant
-	      (newtype,
-	       merge_attributes (TYPE_ATTRIBUTES (newtype),
-				 TYPE_ATTRIBUTES (oldtype)));
-	}
-      else
-	TREE_TYPE (newdecl)
-	  = TREE_TYPE (olddecl)
-	  = common_type (newtype, oldtype);
-    }
+  TREE_TYPE (newdecl)
+    = TREE_TYPE (olddecl)
+    = common_type (newtype, oldtype);
 
   /* Lay the type out, unless already done.  */
   if (oldtype != TREE_TYPE (newdecl))
@@ -1331,33 +1307,27 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
 
   /* Merge the type qualifiers.  */
   if (TREE_READONLY (newdecl))
-    TREE_READONLY (write_olddecl) = 1;
+    TREE_READONLY (olddecl) = 1;
 
   if (TREE_THIS_VOLATILE (newdecl))
     {
-      TREE_THIS_VOLATILE (write_olddecl) = 1;
+      TREE_THIS_VOLATILE (olddecl) = 1;
       if (TREE_CODE (newdecl) == VAR_DECL)
 	make_var_volatile (newdecl);
     }
 
   /* Keep source location of definition rather than declaration.  */
-  /* When called with different_binding_level set, keep the old
-     information so that meaningful diagnostics can be given.  */
-  if (DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0
-      && ! different_binding_level)
+  if (DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0)
     DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl);
 
   /* Merge the unused-warning information.  */
   if (DECL_IN_SYSTEM_HEADER (olddecl))
     DECL_IN_SYSTEM_HEADER (newdecl) = 1;
   else if (DECL_IN_SYSTEM_HEADER (newdecl))
-    DECL_IN_SYSTEM_HEADER (write_olddecl) = 1;
+    DECL_IN_SYSTEM_HEADER (olddecl) = 1;
 
   /* Merge the initialization information.  */
-  /* When called with different_binding_level set, don't copy over
-     DECL_INITIAL, so that we don't accidentally change function
-     declarations into function definitions.  */
-  if (DECL_INITIAL (newdecl) == 0 && ! different_binding_level)
+   if (DECL_INITIAL (newdecl) == 0)
     DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
 
   /* Merge the section attribute.
@@ -1397,8 +1367,6 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
       TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl);
       /* This is since we don't automatically
 	 copy the attributes of NEWDECL into OLDDECL.  */
-      /* No need to worry about different_binding_level here because
-	 then TREE_PUBLIC (newdecl) was true.  */
       TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
       /* If this clears `static', clear it in the identifier too.  */
       if (! TREE_PUBLIC (olddecl))
@@ -1406,24 +1374,15 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
     }
   if (DECL_EXTERNAL (newdecl))
     {
-      if (! different_binding_level || different_tu)
-	{
-	  /* Don't mess with these flags on local externs; they remain
-	     external even if there's a declaration at file scope which
-	     isn't.  */
-	  TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
-	  DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl);
-	}
+      TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
+      DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl);
+
       /* An extern decl does not override previous storage class.  */
       TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl);
       if (! DECL_EXTERNAL (newdecl))
 	{
 	  DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl);
 	  DECL_COMMON (newdecl) = DECL_COMMON (olddecl);
-	  /* If we have two non-EXTERNAL file-scope decls that are
-	     the same, only one of them should be written out.  */
-	  if (different_tu)
-	    TREE_ASM_WRITTEN (newdecl) = 1;
 	}
     }
   else
@@ -1469,11 +1428,8 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
 	     definition.  */
 	  if (new_is_definition)
 	    {
-	      if (! different_binding_level)
-		{
-		  TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
-		  DECL_BUILT_IN_CLASS (olddecl) = NOT_BUILT_IN;
-		}
+	      TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
+	      DECL_BUILT_IN_CLASS (olddecl) = NOT_BUILT_IN;
 	    }
 	  else
 	    {
@@ -1488,11 +1444,7 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
       if (! new_is_definition)
 	{
 	  DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
-	  /* When called with different_binding_level set, don't copy over
-	     DECL_INITIAL, so that we don't accidentally change function
-	     declarations into function definitions.  */
-	  if (! different_binding_level)
-	    DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
+	  DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
 	  DECL_SAVED_INSNS (newdecl) = DECL_SAVED_INSNS (olddecl);
 	  DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl);
 	  DECL_ESTIMATED_INSNS (newdecl) = DECL_ESTIMATED_INSNS (olddecl);
@@ -1504,9 +1456,7 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
 	    {
 	      DECL_INLINE (newdecl) = 1;
 	      DECL_ABSTRACT_ORIGIN (newdecl)
-		= (different_binding_level
-		   ? DECL_ORIGIN (olddecl)
-		   : DECL_ABSTRACT_ORIGIN (olddecl));
+		= DECL_ABSTRACT_ORIGIN (olddecl);
 	    }
 	}
       else
@@ -1518,8 +1468,6 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
 	    DECL_INLINE (newdecl) = 1;
 	}
     }
-  if (different_binding_level)
-    return;
 
   /* Copy most of the decl-specific fields of NEWDECL into OLDDECL.
      But preserve OLDDECL's DECL_UID.  */
@@ -1547,24 +1495,18 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype,
    if appropriate.
 
    If safely possible, alter OLDDECL to look like NEWDECL, and return
-   true.  Otherwise, return false.
-
-   When DIFFERENT_BINDING_LEVEL is true, NEWDECL is an external
-   declaration, and OLDDECL is in an outer scope and should thus not
-   be changed.  */
+   true.  Otherwise, return false.  */
 
 static bool
-duplicate_decls (tree newdecl, tree olddecl,
-		 bool different_binding_level, bool different_tu)
+duplicate_decls (tree newdecl, tree olddecl)
 {
   tree newtype, oldtype;
 
   if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype))
     return false;
 
-  merge_decls (newdecl, olddecl, newtype, oldtype,
-	       different_binding_level, different_tu);
-  return !different_binding_level;
+  merge_decls (newdecl, olddecl, newtype, oldtype);
+  return true;
 }
   
 
@@ -1745,7 +1687,7 @@ pushdecl (tree x)
 		 IDENTIFIER_POINTER (name));
 
       old = lookup_name_current_level (name);
-      if (old && duplicate_decls (x, old, 0, false))
+      if (old && duplicate_decls (x, old))
 	{
 	  /* For PARM_DECLs, old may be a forward declaration.
 	     If so, we want to remove it from its old location
@@ -1773,8 +1715,7 @@ pushdecl (tree x)
  	  tree ext = any_external_decl (name);
 	  if (ext)
 	    {
-	      if (duplicate_decls (x, ext, scope != global_scope,
-				   false))
+	      if (duplicate_decls (x, ext))
 		x = copy_node (ext);
 	    }
 	  else
@@ -6606,7 +6547,7 @@ merge_translation_unit_decls (void)
 
 	  /* Print any appropriate error messages, and partially merge
 	     the decls.  */
-	  (void) duplicate_decls (decl, global_decl, true, true);
+	  (void) duplicate_decls (decl, global_decl);
 	}
 
   htab_delete (link_hash_table);