RFR(T): 8233530: gcc 5.4 build warning -Wc++14-compat after JDK-8233359

[David Holmes]

On 6/11/2019 11:17 pm, Thomas Stüfe wrote:
> Hi David,
> 
> sorry for that. I had marked this as trivial, understood your initial 
> answer as valid Review and pushed this after getting a second review 
> from Goetz.
> 
> But no problem, I can do a follow up patch. What are the remaining 
> criticisms? Removal of the _GNUG_ define?

I'll let Kim decide whether it is worth following up on this.

Thanks,
David

> Best Regards, Thomas
> 
> 
> On Wed, Nov 6, 2019 at 2:09 PM David Holmes <david.holmes at oracle.com 
> <mailto:david.holmes at oracle.com>> wrote:
> 
>     I was surprised to see this got pushed before Kim had had a chance to
>     respond and when there was apparently still an open question to me. :(
> 
>     And now we see it breaks gcc 4.8.5.
> 
>     David
> 
>     On 6/11/2019 3:37 pm, Kim Barrett wrote:
>      >> On Nov 5, 2019, at 8:44 PM, David Holmes
>     <david.holmes at oracle.com <mailto:david.holmes at oracle.com>> wrote:
>      >>
>      >> On 6/11/2019 11:38 am, Kim Barrett wrote:
>      >>>> On Nov 5, 2019, at 2:06 AM, Thomas Stüfe
>     <thomas.stuefe at gmail.com <mailto:thomas.stuefe at gmail.com>> wrote:
>      >>>>
>      >>>> Hi all,
>      >>>>
>      >>>> may I please have reviews for this small build fix:
>      >>>>
>      >>>> Issue: https://bugs.openjdk.java.net/browse/JDK-8233530
>      >>>> Webrev:
>     http://cr.openjdk.java.net/~stuefe/webrevs/8233530-wc14-compat/webrev.00/webrev/
>      >>>> Prior discussion:
>     https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2019-November/036726.html
>      >>>>
>      >>>> Thank you,
>      >>>>
>      >>>> Thomas
>      >>> The "#ifdef __GNUG__" should not be needed or used.
>      >>> There are a dozen existing uses of PRAGMA_DIAG_PUSH.
>      >>> While there aren't currently any other direct uses of
>      >>> PRAGMA_DISABLE_GCC_WARNING, there are indirect uses via other
>      >>> PRAGMA_DISABLE_xxx macros.
>      >>> None of those have __GNUX__ protections (for any X).
>      >>
>      >> Well AFAICS they reside in a gcc specific file:
>     compilerWarnings_gcc.hpp. But we also take steps in
>     compilerWarnings.hpp to accommodate their use in source code when
>     other compilers are used.
>      >>
>      >> #ifndef PRAGMA_DISABLE_GCC_WARNING
>      >> #define PRAGMA_DISABLE_GCC_WARNING(name)
>      >> #endif
>      >>
>      >> so I agree we should not need any guard to make this gcc only -
>     unless we really do want to control the version.
>      >
>      > If we need to control the version it’s applied to, we can use
>     PRAGMA_STRINGOP_TRUNCATION_IGNORED as a model.
>      > Or just version-conditionalize at the one place it’s needed, for
>     now.  If more -Wc++14-compat issues come up later
>      > then we can introduce a new macro.
>      >
>      >
>