RFC: JEP JDK-8208089: Implement C++14 Language Features

[Aleksei Voitylov]

Kim,

from an ARM port perspective, the stable GCC version is 4.9. The port 
compiles with stock GCC 7.3 but a lot of testing is required before 
moving to GCC 7.3. I agree on the overall direction and we'll commit 
resources to testing it further, but from an ARM port perspective it may 
happen JDK 12 is a little too optimistic.

GCC x86 is a lot more stable than for ARM32 and AARCH64.

-Aleksei

On 05/10/2018 00:09, Kim Barrett wrote:
>> On Oct 4, 2018, at 9:17 AM, Aleksei Voitylov <aleksei.voitylov at bell-sw.com> wrote:
>>
>> Kim,
>>
>> Thank you for posting this. It's an important step to make. I wanted to clarify a couple of points:
>>
>> 1. Since this is infrastructure JEP, is the version of JDK which will undergo such changes going to be some future version or does it apply to past versions as well? I'm concerned with how we can simplify security backports to 8u which (I currently assume) is not subject to this change.
> Future version (perhaps as soon as JDK 12).  I don't think there is
> any desire to backport this change.  And yes, introducing the use of
> new language features will make backports even more interesting than
> they already are.  That seems unavoidable if we're going to pursue
> this direction.
>
>> 2. Which versions of GCC do you tentatively consider at this point? Non-x86 ports may have a problem upgrading to a specific version of GCC which the shared code will use and may need additional lead time to adjust.
> I think our (ad hoc) testing has been limited to gcc 7.x. But looking
> at the gcc language conformance tables and release notes, gcc 5.x
> might be good enough, and gcc 6.x seems fairly likely sufficient. Of
> course, older versions are more likely to have bugs in some of these
> new features. Updating the minimum supported versions for gcc and
> clang are noted as TBD in the JEP.
>