PR debug/29436, c/32326

        PR debug/29436, c/32326
        * tree.c (build_type_attribute_qual_variant): Refuse to make
        a distinct copy of a struct/enum type.  Use build_distinct_type_copy.
        * doc/extend.texi (Type Attributes): Don't encourage people to add
        attributes to struct/enum types in a typedef.  Fix
        transparent_union example.

        * tree-inline.c (remap_type_1): Remove code that's redundant with
        remap_type.
        (build_duplicate_type): Set id.copy_decl.
        * c-common.c (handle_transparent_union_attribute): Simplify logic.

From-SVN: r130297

1 files changed, 18 insertions, 7 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 81c54d0..9c65474 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -3666,15 +3666,26 @@ build_type_attribute_qual_variant (tree ttype, tree attribute, int quals)
       tree ntype;
       enum tree_code code = TREE_CODE (ttype);
 
-      ntype = copy_node (ttype);
+      /* Building a distinct copy of a tagged type is inappropriate; it
+	 causes breakage in code that expects there to be a one-to-one
+	 relationship between a struct and its fields.
+	 build_duplicate_type is another solution (as used in
+	 handle_transparent_union_attribute), but that doesn't play well
+	 with the stronger C++ type identity model.  */
+      if (TREE_CODE (ttype) == RECORD_TYPE
+	  || TREE_CODE (ttype) == UNION_TYPE
+	  || TREE_CODE (ttype) == QUAL_UNION_TYPE
+	  || TREE_CODE (ttype) == ENUMERAL_TYPE)
+	{
+	  warning (OPT_Wattributes,
+		   "ignoring attributes applied to %qT after definition",
+		   TYPE_MAIN_VARIANT (ttype));
+	  return build_qualified_type (ttype, quals);
+	}
 
-      TYPE_POINTER_TO (ntype) = 0;
-      TYPE_REFERENCE_TO (ntype) = 0;
-      TYPE_ATTRIBUTES (ntype) = attribute;
+      ntype = build_distinct_type_copy (ttype);
 
-      /* Create a new main variant of TYPE.  */
-      TYPE_MAIN_VARIANT (ntype) = ntype;
-      TYPE_NEXT_VARIANT (ntype) = 0;
+      TYPE_ATTRIBUTES (ntype) = attribute;
       set_type_quals (ntype, TYPE_UNQUALIFIED);
 
       hashcode = iterative_hash_object (code, hashcode);