----- Mail original ----- > De: "Brian Goetz" <brian.go...@oracle.com> > À: "Remi Forax" <fo...@univ-mlv.fr> > Cc: "daniel smith" <daniel.sm...@oracle.com>, "Daniel Heidinga" > <daniel_heidi...@ca.ibm.com>, "valhalla-spec-experts" > <valhalla-spec-experts@openjdk.java.net> > Envoyé: Mercredi 7 Mars 2018 19:28:00 > Objet: Re: CONSTANT_Dynamic bootstrap signature restriction
>> Daniel (S), Brian, >> i think your view on this subject is biased by the fact that you built that >> library. > > I can understand why you'd think that, but allow me to correct. My view > is biased by the fact that I built the _first_ such library, and it was > pretty annoying, and I want to save future programmers from this > unnecessary annoyance. And that we're working on language support that > virtually guarantees that others will want to write similar Java > libraries. If this were just about compilers emitting bytecode, I > wouldn't care. Sure, javac support will help to have new users for condy but given the number people that have reviewed this API, it doesn't seem too popular, btw doing a proper review is on my todo list. Anyway, if you want to get ride of the first 3 parameters, you can trampoline, i.e having only one BSM that takes as first constant argument a method handle that construct the constants with fewer arguments and just call it. It's what i've done for the first version of cplisp [1]. Obviously it's not great in term of security so you also need to check that the given method handle had really been constructed from the lookup using lookup.revealDirect. > >> And i will re-use the argument than Brian use rightly about java.lang.invoke, >> not a lot of people will write BSMs, so modifying an already complex API call >> (callsite info * lazy loading of constants * conversion of bsm arguments * >> varargs) to take care of hiding potentially unused arguments only for few >> users >> does not worth the added complexity. > > I am saying that I imagine a future where the number of people writing > BSMs for condy is at least 100x bigger than it has been historically. > Again, if I thought this was just about me and you and Charlie, I > wouldn't care. But I don't think that's the case here. I can imagine a lot of things, but we can also wait and see if the API becomes popular now that we are in a 6 month cadence. Rémi [1] https://github.com/forax/cplisp
