How do I disable warnings across gcc versions?

[Andy Lutomirski <luto at amacapital dot net>]

This code warns (incorrectly, but that's a whole separate issue):

double foo(double a, double b)
{
  bool option1_ok, option2_ok;
  double option1, option2;
  if (a == 0) {
    option1_ok = false;
  } else {
    option1 = b;
    option1_ok = true;
  }
  if (a == 1) {
    option2_ok = false;
  } else {
    option2 = b;
    option2_ok = true;
  }
  if (option1_ok) return option1;
  if (option2_ok) return option2;
  return 7;
}

Unfortunately, the bogus warning is -Wuninitialized in gcc 4.6 and
-Wmaybe-uninitialized in gcc 4.7.  The obvious way to silence the
warning is to wrap it in:

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wuninitialized"
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
...
#pragma GCC diagnostic pop

It silences the original warning, but now gcc 4.6 says:
warning: unknown option after ‘#pragma GCC diagnostic’ kind [-Wpragmas]

This seems to defeat the purpose, and adding
#pragma GCC diagnostic ignored "-Wpragmas"
is a little gross.  How am I supposed to do this?

Thanks,
Andy