http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44384
--- Comment #4 from Mark Eklund <meklund at cisco dot com> 2011-04-21 15:17:37 UTC --- Although "subobject" isn't well defined in the documentation, the below comments from tree-object-size.c revision r171388 lines 63-68 would indicate that subobject is the innermost array. /* * * object_sizes[0] is upper bound for number of bytes till the end of * the object. * object_sizes[1] is upper bound for number of bytes till the end of * the subobject (innermost array or field with address taken). * object_sizes[2] is lower bound for number of bytes till the end of * the object and object_sizes[3] lower bound for subobject. */