Support unnamed/anonymous structs and unions (#5)

* Regenerate c-parse.c with Andrew Bison

* Add unnamed struct/union members to C grammar

Based on gcc-mirror/gcc@ffc3b0f

* Handle nested unnamed structs/unions

Based on gcc-mirror/gcc@e9b2c82

* Check that only unnamed structs and unions are allowed

Based on gcc-mirror/gcc@3e96a2f
and gcc-mirror/gcc@85d4905

gcc/c-decl.c

@@ -433,7 +433,6 @@ static tree lookup_tag_reverse		PROTO((tree));
 static tree grokdeclarator		PROTO((tree, tree, enum decl_context,
 					       int));
 static tree grokparms			PROTO((tree, int));
-static int field_decl_cmp		PROTO((const GENERIC_PTR, const GENERIC_PTR));
 static void layout_array_type		PROTO((tree));
 
 /* C-specific option variables.  */
@@ -5691,6 +5690,21 @@ grokfield (filename, line, declarator, declspecs, width)
 {
   tree value;
 
+  if (declarator == NULL_TREE && width == NULL_TREE)
+    {
+      /* This is an unnamed decl.  We only support unnamed
+	 structs/unions, so check for other things and refuse them.  */
+      tree type = TREE_VALUE (declspecs);
+
+      if (TREE_CODE (type) == TYPE_DECL)
+	type = TREE_TYPE (type);
+      if (TREE_CODE (type) != RECORD_TYPE && TREE_CODE (type) != UNION_TYPE)
+	{
+	  error ("unnamed fields of type other than struct or union are not allowed");
+	  return NULL_TREE;
+	}
+    }
+
   /* The corresponding pop_obstacks is in finish_decl.  */
   push_obstacks_nochange ();
 
@@ -5703,25 +5717,6 @@ grokfield (filename, line, declarator, declspecs, width)
   return value;
 }
 
-/* Function to help qsort sort FIELD_DECLs by name order.  */
-
-static int
-field_decl_cmp (xp, yp)
-     const GENERIC_PTR xp;
-     const GENERIC_PTR yp;
-{
-  tree *x = (tree *)xp, *y = (tree *)yp;
-
-  if (DECL_NAME (*x) == DECL_NAME (*y))
-    return 0;
-  if (DECL_NAME (*x) == NULL)
-    return -1;
-  if (DECL_NAME (*y) == NULL)
-    return 1;
-  if (DECL_NAME (*x) < DECL_NAME (*y))
-    return -1;
-  return 1;
-}
 
 /* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T.
    FIELDLIST is a chain of FIELD_DECL nodes for the fields.
@@ -5958,43 +5953,6 @@ finish_struct (t, fieldlist, attributes)
 
   TYPE_FIELDS (t) = fieldlist;
 
-  /* If there are lots of fields, sort so we can look through them fast.
-     We arbitrarily consider 16 or more elts to be "a lot".  */
-  {
-    int len = 0;
-
-    for (x = fieldlist; x; x = TREE_CHAIN (x))
-      {
-	if (len > 15)
-	  break;
-	len += 1;
-      }
-    if (len > 15)
-      {
-	tree *field_array;
-	char *space;
-
-	len += list_length (x);
-	/* Use the same allocation policy here that make_node uses, to
-	   ensure that this lives as long as the rest of the struct decl.
-	   All decls in an inline function need to be saved.  */
-	if (allocation_temporary_p ())
-	  space = savealloc (sizeof (struct lang_type) + len * sizeof (tree));
-	else
-	  space = oballoc (sizeof (struct lang_type) + len * sizeof (tree));
-
-	TYPE_LANG_SPECIFIC (t) = (struct lang_type *) space;
-	TYPE_LANG_SPECIFIC (t)->len = len;
-
-	field_array = &TYPE_LANG_SPECIFIC (t)->elts[0];
-	len = 0;
-	for (x = fieldlist; x; x = TREE_CHAIN (x))
-	  field_array[len++] = x;
-
-	qsort (field_array, len, sizeof (tree), field_decl_cmp);
-      }
-  }
-
   for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
     {
       TYPE_FIELDS (x) = TYPE_FIELDS (t);