On 28/03/2019 10:19, Michael Rasmussen wrote:
It was my assumption that the reason adding private methods were allowed with
redefineClass was to support adding/removing lambdas from method bodies, since
javac converts those into private methods.
It came about in JDK 6 as part of the effort to instrument native
methods. The intention, in Java SE 6, was to provide a way for JVM TI
and java agents to wrap native methods at load time. The
SetNativeMethodPrefix function in the JVM TI spec documents this
feature. Somehow, there was an attempt to get do the equivalent for late
binding agents but that has massive implications, not just the JVM TI
spec, but to wide areas of the platform. I see the VM option as a
pragmatic approach to allow the mistake be removed over time and to give
time for agent writers that might be using this to show up with their
use-cases if it's anything other than instrumenting native methods.
-Alan
