.:

	PR c++/21166
	* c-decl.c (finish_struct):  Only set DECL_PACKED on a field
	when its natural alignment is > BITS_PER_UNIT.
	* stor-layout.c (finalize_type_size): Revert my patch of 2005-08-08.
	* c-common.c (handle_packed_attribute): Ignore packing on a field
	whose type is naturally char aligned.
cp:
	PR c++/21166
	* class.c (check_field_decls): Only set DECL_PACKED on a field
	when its natural alignment is > BITS_PER_UNIT.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@107599 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 4 deletions

diff --git a/gcc/c-common.c b/gcc/c-common.c
index b416a5d3648..43c147b3068 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -4065,17 +4065,23 @@ handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
 
 	     struct Foo {
 	       struct Foo const *ptr; // creates a variant w/o packed flag
-	       } __ attribute__((packed)); // packs it now.
-	  */
+	     } __ attribute__((packed)); // packs it now.
+	   */
 	  tree probe;
 
 	  for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
 	    TYPE_PACKED (probe) = 1;
 	}
-
     }
   else if (TREE_CODE (*node) == FIELD_DECL)
-    DECL_PACKED (*node) = 1;
+    {
+      if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
+	warning (OPT_Wattributes,
+		 "%qE attribute ignored for field of type %qT",
+		 name, TREE_TYPE (*node));
+      else
+	DECL_PACKED (*node) = 1;
+    }
   /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
      used for DECL_REGISTER.  It wouldn't mean anything anyway.
      We can't set DECL_PACKED on the type of a TYPE_DECL, because