[OpenJDK 2D-Dev] RFR: 8246032: Implementation of JEP 347: Adopt C++14 Language Features in HotSpot

[Kim Barrett]

> On Jun 14, 2020, at 12:45 AM, Philip Race <philip.race at oracle.com> wrote:
> 
> Kim,
> 
> 
> Until it says in "the JDK" and not "in HotSpot" you have not addressed my main point.
> Please rename the JEP.

I think this JEP is primarily about updating the HotSpot-specific
subset of C++ and usage guidance to include some C++14 features.
HotSpot usage is already different in some ways from C++ code in other
parts of the JDK.  For example, HotSpot code doesn't use global
operator new; that isn't likely to change, and non-HotSpot code
doesn't have access to the alternatives defined and used but not
exported by HotSpot.

As a necessary prerequisite for that, the JDK build system is being
updated to enable the use of C++14 features.  It's probably possible
to limit the scope of the language change to HotSpot, but that doesn't
seem useful.  It also probably wasn't possible while Solaris was still
in the mix.

It is expected that groups responsible for other parts of the JDK will
also want to take advantage of that build change, but I think it's up
to those other groups to decide on an adoption strategy.  I have no
reason to think the choices being suggested here as appropriate for
HotSpot are appropriate JDK-wide.

I can't say whether a JEP is generally needed; maybe it's simply
"C++14 - yes" in some areas.  Also, some of the reasons for this being
a JEP no longer apply.  For example, Solaris was going to require at
least a major ABI change, and at the time the JEP was created there
was no path to C++14 for the AIX/PPC port; both of those needed
visibility and discussion that seemed best provided via the JEP
process.

> -phil.
> 
> On 6/13/20, 8:48 PM, Kim Barrett wrote:
>>> On Jun 10, 2020, at 2:26 AM, Kim Barrett<kim.barrett at oracle.com>  wrote:
>>> 
>>>> On Jun 8, 2020, at 4:07 PM, Philip Race<philip.race at oracle.com>  wrote:
>>>> BTW the JEP (https://bugs.openjdk.java.net/browse/JDK-8208089) still says
>>>>> For Solaris: Add the -std=c++14 compiler option. .....
>>>> So I am sure there is still some room to update the JEP :-)
>>> Yeah, I have some updates to make.  I also need to do a bit of work on the feature lists.
>> I think the JEP updates are done now.