[foreign-abi] RFR: 8248420: Add a variant of VaList::make which takes a NativeScope [v6]

[Jorn Vernee]

On Thu, 16 Jul 2020 18:53:55 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

>> This is borderline in terms of requiring its own liveness check:
>> 
>> @Override
>> public MemoryAddress address() {
>>      return ptr;
>> }
>> Of course, in the current impl, since `ptr` is attached to the original segment, attempting to use the address will
>> fail (if parent valist has been closed already).
>
> After a suggestion from Maurizio I've re-written the VaListTest to try and test all the implementations on the
> different platforms, instead of just the implementation for the current platform.
> This results in 4 different versions of each test being run; once for each platform, where the reading of the VaList is
> done in Java as well, and then one native implementation. The needed parameters are injected into tests using
> DataProviders. For the struct tests this was a little tricky, since we need to inject the platform specific
> C_INT/C_LONGLONG/C_FLOAT layouts into the struct layout. This resulted in the current code complexity.  Upcalls are
> still only tested for the current platform, since the creation of the va_list happens in native code in that case, and
> we only have access to 1 platform in that case :)
> ---
> 
> I've also cleaned up the sumStack test, which wasn't actually using a VaList, as well as reduced some copy-pasted code
> which was previously used for debugging, but never collapsed back into for-loops afterwards.

Actually, I'll submit a separate PR  for the test re-write, since it is quite substantial

-------------

PR: https://git.openjdk.java.net/panama-foreign/pull/237