RFC: JEP JDK-8208089: Implement C++14 Language Features (original) (raw)

Volker Simonis volker.simonis at gmail.com
Mon Nov 19 08:21:08 UTC 2018

On Mon, Nov 19, 2018 at 9:00 AM Kim Barrett <kim.barrett at oracle.com> wrote:

> On Nov 19, 2018, at 2:04 AM, Kim Barrett <kim.barrett at oracle.com> wrote: > >> On Nov 19, 2018, at 1:31 AM, David Holmes <david.holmes at oracle.com> wrote: >> I think it is important that all the port owners buy into this. > > At least one port (aixppc) presently seems to have no way to support this change, because > the compiler being used is seriously deficient and appears to be languishing. (It doesn’t even > support C++11, let alone C++14.) I think the community could (and in my opinion, should) > chose to move ahead despite that. If a new and adequate compiler is expected “soon” then > the community might choose to wait, or might proceed and let that port languish until the new > compiler is available. I think that’s all part of the discussion that should happen around the > targeting of this JEP. I hope this inadequate compiler on a relatively niche platform won’t be > an indefinite blocker in this area. Here’s what Volker said on the build-dev list, 2017-07-19, subject “C++11/C++14 support in XLC ?” - SAP is currently maintaining the AIX port in the OpenJDK and we're willing to do that in the future. But we're not IBM and we can not decide about the XLC feature list. If Oracle and the OpenJDK community finally decide to use C++11/14 features which are not available in XLC we have to live with that. We can either escalate the XLC deficiencies to IBM and suspend the port until the compiler gets fixed. Or we can switch the port to use the GCC tool chain with all the pros (bigger compatibility with Linux platforms) and cons (porting effort, testing, compatibility with other AIX software compiled with XLC, compiler support). While the GCC alternative sounds very appealing at a first glance it really isn't that perfect in reality, especially not for our commercial SAP JVM version of OpenJDK. One problem is the fact that there's no official support for GCC on AIX, the other is compatibility. Just think you had to replace Solaris Studio by GCC on Solaris :) He had more to say on the general topic at the time. I don’t know if anything has changed in the intervening nearly 1 1/2 years.

Not really. IBM is working on a new compiler which is in Beta now. But neither have I tested it nor do I know exactly if it will have full C++11/14 support.

As I wrote before, this is a chicken/egg problem which I can not solve and I agree that it shouldn't be a blocker for OpenJDK. Therefore, please go ahead and use whichever feature the OpenJDK community agrees upon.

Regards, Volker

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