test-stdalign.c breaks on i686 on Fedora Rawhide (gcc 4.7)

[Richard W.M. Jones]

  CC     test-stdalign.o
test-stdalign.c:70:1: error: static assertion failed: "verify (alignof 
(int64_t) == offsetof (int64_t_helper, slot2))"
test-stdalign.c:73:1: error: static assertion failed: "verify (alignof (double) 
== offsetof (double_helper, slot2))"
make[4]: *** [test-stdalign.o] Error 1

The code which fails is a macro that expands to:

  typedef struct { char slot1; int64_t slot2; } int64_t_helper;
  verify (alignof (int64_t) == offsetof (int64_t_helper, slot2));
 /*...*/
  typedef struct { char slot1; double slot2; } double_helper;
  verify (alignof (double) == offsetof (double_helper, slot2));

I printed out the actual numbers and they are:

  alignof (int64_t) = 8
  offsetof (int64_t_helper, slot2) = 4
  alignof (double) = 8
  offsetof (double_helper, slot2) = 4

Compiler and kernel version:

  gcc-4.7.0-0.9.fc17.i686
  Linux fedorarawhidex32 2.6.38.6-27.fc15.i686.PAE #1 SMP Sun May 15 17:39:47 
UTC 2011 i686 i686 i386 GNU/Linux

This is with the latest gnulib, updated this evening.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v