[Bug c++/45668] New: Request warning for mismatched declaration/definition attributes (instead of chances for an indirect error)

["tbptbp at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

As g++ now may, or may not, produce an indirect error on mismatched attributes
between a forward declaration and later definition, and that is incredibly
confusing to the end-user (aka me), i hereby humbly ask for a warning in such
condition; a hint at the problematic declaration would be a plus.

But, really, anything but that cryptic mismatched prototype error one may get
when *using* such ill-formed type would be great. 

Executive summary for PR 45642
class foo;
class bar {
        void foobar(foo &);
};
class __attribute((aligned(16))) foo {};
// if unlucky, an error about void bar::foobar(foo &)
// not matching void bar::foobar(foo &)
// when the culprit is foo's attributes.
void bar::foobar(foo &) {}


-- 
           Summary: Request warning for mismatched declaration/definition
                    attributes (instead of chances for an indirect error)
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tbptbp at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45668