On 07/11/2012 10:24 PM, John Rose wrote: > On Jul 11, 2012, at 2:29 AM, Rémi Forax wrote: > >> just a question, even if it's not a big deal if one is able to generate >> bytecode, >> why Hidden is not a top level type of java.lang.invoke ? > > Good question. The answer is that hiding of stack frames is limited to > hiding method handle implementation details. Specifically, the frames > that are to be hidden are those which are not specified by the JSR 292 > modifications to the JVMS. > > For example, if you have z=filterReturnValue(::x,::y), and some method > m does z.invoke(), the visible stack frames will be m calling x and m > calling y. Internally there will be a continuation during the call to > x which waits to apply y. This must be some sort of activation frame, > but the JVMS requires it to be hidden. In JDK 7 it was a ricochet > frame (hand assembly code) and in JDK 8 it will be a lambda form > activation (bytecode). Both must be suppressed in backtraces. > > A general Lisp-machine-style convention for redacting back traces > would be interesting, but it would also require a new JSR. > > On the other hand, Hidden could be top-level. It's a matter of coding > taste. Binding it to LF makes it more clear that it has a specific use.
Emulating a language call using bytecode is something that should ring a bell for a lot of people of this list :) And even for the JDK, it by example generates bytecode when optimizing a call to j.l.r.Method and this bytecode should not appear in the stacktrace. > > — John Rémi _______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
