Re: GCC 4.0 RC2 Available

[Mark Mitchell <mark at codesourcery dot com>]

Andrew Haley wrote:
> Geoffrey Keating writes:
>  > Mark Mitchell <mark@codesourcery.com> writes:
>  > 
>  > > RC2 is available here:
>  > > 
>  > >   ftp://gcc.gnu.org/pub/gcc/prerelease-4.0.0-20050417/
>  > > 
>  > > As before, I'd very much appreciate it if people would test these bits
>  > > on primary and secondary platforms, post test results with the
>  > > contrib/test_summary script, and send me a message saying whether or
>  > > not there are any regressions, together with a pointer to the results.
>  > 
>  > Bad news, I'm afraid.
>
> It's a bug in dbxout.  A field is marked as DECL_IGNORED_P, but
> dbxout_type_fields() still tries to access it.
>
> Andrew.
>
>
> 2005-04-19  Andrew Haley  <aph@redhat.com>
>
> 	* dbxout.c (dbxout_type_fields): Check DECL_IGNORED_P before
> 	looking at a field's bitpos.

The C++ front-end (and probably the C front-end) strips zero-width (and 
possibly unnamed) bitfields after class layout.  This can be justified 
in that those bitfields only affect layout; one doesn't need the 
middle-end to copy them around, etc.  So, you could probably fix this in 
the Java front end in the same way.  From your patch, it looks like 
you're letting the back end see these bitfields, and also that their 
DECL_SIZE is not set correctly, which is dangerous in general.

So, I would suggest fixing this in the Java front end.

--
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304