My sbt plugin is working

[Mark Hammons]

Ah I see,

Is there any chance that this will be put into an early access release anytime 
soon? I've never built openjdk myself before.

I'll probably go ahead and generate a java interface for my scala trait to 
inherit from for now, since I would like my plugin to depend on the latest EA 
build of panama instead of requiring users to build a JDK to use it, but I may 
well add a branch to my code that uses the LibraryLookup API to get pure scala 
bindings so I can switch to that when it becomes available in EA builds.

Thanks a ton for the help Maurizio,
Mark



On Monday, November 11, 2019 4:22:34 PM CET Maurizio Cimadamore wrote:
> I was referring to SystemABI in foreign-abi - in that branch, the API is
> public, and there's a LibraryLookup API to lookup the library symbol you
> are looking for.
> 
> Maurizio
> 
> On 11/11/2019 14:24, Mark Hammons wrote:
> > Hi Maurizio,
> > 
> > I'm not sure I fully understand. SystemABI resides in
> > jdk.internal.foreign,
> > and trying to access it gives me an IllegalAccessError. Is there an API
> > I'm
> > missing under java.foreign to do this? And it's not very clear how I'd use
> > SystemABI to look up the right function and get a method handle. Also, if
> > it requires poking around in java internals, won't that make my library
> > fairly difficult to use as the users would probably have to add special
> > jvm options to override the IllegalAccessError?
> > 
> > Thanks,
> > Mark
> > 
> > On Monday, November 11, 2019 2:26:47 PM CET Maurizio Cimadamore wrote:
> >> On 11/11/2019 12:40, Mark Hammons wrote:
> >>> However, I was curious if it would be feasible for java.foreign to be a
> >>> little more lenient in what it binds to. If I were able to define a
> >>> method like this in scala:
> >>> @NativeFunction("(i32*)v")
> >>> def fn(i: Array[Int]): Unit
> >>> 
> >>> and have java foreign recognize that as a valid binding
> >> 
> >> Uhm - not 100% sure about that. (i32*) means - one i32 parameter,
> >> followed by a varargs list - e.g. in C
> >> 
> >> f(int i, ...)
> >> 
> >> So, how can you prove that an Array[Int] is the right type to hold all
> >> of the parameters?
> >> 
> >> One thing you might want to consider actually, would be for you to use
> >> the SystemABI API directly, to get a MethodHandle that accessed the
> >> right native function, and maybe add a varargs adaptation on top. In
> >> other words, I'm not sure how much of what you are doing needs
> >> panama/foreign an the annotation stuff, and how much of what you could
> >> do using the low level support in foreign-abi. Since that's lower level
> >> it will give you many more options on how to surface it at the Scala
> >> level.
> >> 
> >> Maurizio
> >> 
> >>> , that would allow me
> >>> to have a pure scala binding and make java.foreign 100% compatible with
> >>> scala. I'm hopefuly that this is a possibility, though I'd understand if
> >>> it's not something the project panama team wants to do or devote
> >>> resources to.