On Thu, Dec 22, 2011 at 8:47 PM, Aldy Hernandez <al...@redhat.com> wrote: > The problem here is that with -fnon-call-exceptions, a memory dereference > may trap, but when we instrument the store, we have lost the landing pad > information. > > One solution would be to move the EH information to the TM load/store > instrumentation builtins, but that doesn't get us around the fact that > libitm is not exception safe, and we have no mechanism for taking and > exception (and propagating it) in the middle of a transaction. > > Richard has suggested that another alternative could be to support the > exception case for NULL, but non-null faulting memory references would still > cause a crash. In this case we would simply test for NULL at the start of > the accessors and explicitly throw the exception. > > And yet a third alternative, is to disable the -fgnu-tm and > -fnon-call-exceptions combination. I have implemented this one, as I'd > rather have it not work, than work half-way. > > Torvald, do you have any thoughts on the matter? > > Attached patch for disabling the feature, if you both agree on this > approach.
I think this should be documented at the place -fgnu-tm is documented. Richard.
