Stupid gcc bug

cat <<EOF > foo.m
@interface _Foo
{
}
@end


@interface Foo : _Foo
{
}
@end


@interface _Foo ( XXX)
@end


@implementation _Foo ( XXX)
@end
EOF

gcc -c -ObjC foo.m

and now

sed 's/_Foo/Bar/g' < foo.m > bar.m
gcc -c -ObjC bar.m