On Tue, 2010-04-27 at 11:37 -0400, Chad Mynhier wrote: > On Tue, Apr 27, 2010 at 11:21 AM, Mark Phalan <mark.pha...@sun.com> wrote: > > On Tue, 2010-04-27 at 11:14 -0400, Chad Mynhier wrote: > >> > >> The problem here is the wildcard and the use of args[]. DTrace has no > >> way of knowing that every one of your wildcarded probes (including > >> those that might not exist when you invoke DTrace) has exactly the > >> same argument types, so it bails. > > > > I guess I don't understand how it works but surely it should know it > > from the provider.d file. How does it do it for the kernel - CTF data? > > No, you have the same problem with kernel probes. DTrace can get the > type data via CTF, and it does for the args[] array. It's entirely > possible that those probes matched by the wildcard have exactly the > same number of types and arguments, in which case DTrace could simply > verify that you're using args[0] correctly. But DTrace has no way of > knowing that some kernel module (or library, in the USDT case) that > gets loaded later won't have different argument types. In order to > avoid the problem of running a D script that becomes incorrect via a > modload or dlopen(), DTrace flags the error at compile time.
Ok that makes sense. > > > > >> > >> You'd need to use arg0 and explicitly cast it to the type you want. > > > > Yeah, but thats messy :( > > > > Your other option is not to use the wildcard but rather specify the > probes individually. Yes, this is something I do already but its a little more verbose. I can live with it though. Thanks, -M _______________________________________________ dtrace-discuss mailing list dtrace-discuss@opensolaris.org
