RFR(S): 8184022: Build JDK 10 on OSX 10.12 and above

[Erik Joelsson]

On 2017-07-10 18:09, Hohensee, Paul wrote:
> Hi Erik,
>
> The problem is that the compiler doesn’t issue a warning in this case, but rather a type-mismatch error on NSEventMask, so I can’t turn it off. NSUInteger was being used as an enum, so Apple changed to using a real enum in 10.12 as a matter of code hygiene. The new code in NSApplicationAWT.m is doing the right thing by checking MAC_OS_X_VERSION_MAX_ALLOWED.
>
> What particular problem were you trying to solve? Production, QA and JPRT builds and test runs are done on the oldest supported OSX version, so any use of newer features should be detected very early in the test process. Restricting builds to old OSX versions means that engineers who keep their development boxes up to date (which they should: security, etc.) can’t use them to do JDK development.
That's not exactly true. Apple is making it very hard to stay on older 
versions of the OS compared to other OS vendors. For this reason we are 
not always able to stay on a particular version for Macosx in 
particular. We also in general try to avoid having to fill our build 
servers/environments with just the oldest OSes, because older OSes are 
harder to maintain and less convenient to work with. So instead, we try 
to maintain working build environments on newer OSes that produce 
binaries that are compatible with the oldest we support. So, at least 
from Oracle's perspective, we prefer if builds on different OS versions 
produce equivalent binaries when possible. We certainly don't want to 
prevent building on newer OS/compilers.

If this can't be worked around at the source level, then perhaps we need 
to consider hiding this macro definition behind a configure option that 
we can use internally. I would be open to that. Something like 
--with-macosx-version-min=10.7 which configure could then translate to 
the combination of options currently used. That way, most openjdk 
developers/builders would not need to suffer this Oracle requirement.

/Erik
> Thanks,
>
> Paul
>
> On 7/10/17, 1:10 AM, "Erik Joelsson" <erik.joelsson at oracle.com> wrote:
>
>      Hello,
>      
>      I do not agree to removing that macro. I added those options to help
>      guarantee that a build made on a newer version of macosx would still run
>      on the oldest version currently supported. The macro is not mainly meant
>      to be used in our code, but is picked up by system headers to cause an
>      error if any features newer than 10.7 are used. It may be that we should
>      bump it to a newer version of macosx in JDK 10, but certainly not to 10.12.
>      
>      It seems to me that we instead need to ignore the particular warning for
>      this case.
>      
>      /Erik
>      
>      
>      On 2017-07-09 15:26, Hohensee, Paul wrote:
>      > Please review the following change to get JDK10 to build on OSX 10.12 and above.
>      >
>      > https://bugs.openjdk.java.net/browse/JDK-8184022
>      > http://cr.openjdk.java.net/~phh/8184022/webrev.00/
>      >
>      > I’d very much appreciate a sponsor for this fix. Imo, successful JDK10 builds on all supported platforms would be sufficient testing, but please let me know what I can do to help.
>      >
>      > Slightly revised from the RFE:
>      >
>      > JDK-8182299<https://bugs.openjdk.java.net/browse/JDK-8182299> enabled previously disabled clang warnings and was intended to also enable builds on OSX 10 + Xcode 8. Due to a mixup, this code in jdk/src/java.desktop/macosx/native/libosxapp/NSApplicationAWT.m
>      >
>      >    #if defined(MAC_OS_X_VERSION_10_12) && \
>      >       MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_12 && \
>      >       __LP64__
>      >       / 10.12 changed `mask` to NSEventMask (unsigned long long) for x86_64 builds.
>      >    - (NSEvent *)nextEventMatchingMask:(NSEventMask)mask
>      >    #else
>      >    - (NSEvent *)nextEventMatchingMask:(NSUInteger)mask
>      >    #endif
>      >    untilDate:(NSDate *)expiration inMode:(NSString *)mode dequeue:(BOOL)deqFlag {
>      >
>      > works fine with OSX versions earlier than 10.12, but fails to compile starting with OSX 10.12 due to MAC_OSX_VERSION_MAX_ALLOWED being defined on the compile command line as 10.7.
>      >
>      > The fix is to remove that definition, since it places an artificial upper bound on the OSX version under which JDK10 can be built. A source code search reveals no uses of MAC_OSX_VERSION_MAX_ALLOWED other than in NSApplicationAWT.m and hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp. The latter won't be affected by this change, since it checks for a version > 10.5, which is always true in JDK10.
>      >
>      > Thanks,
>      >
>      > Paul
>      >
>      
>      
>