RFR: 8359830: Incorrect os.version reported on macOS Tahoe 26 (Beta)

[Kevin Rushforth]

On Wed, 18 Jun 2025 06:01:43 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

> Can I please get a review of this change which proposes to address the issue noted in https://bugs.openjdk.org/browse/JDK-8359830?
> 
> macOS operating system's newer version 26 (currently in Beta) is reported as a 16 by older versions of XCode. JDK internally uses the `NSProcessInfo` and `NSOperatingSystemVersion` APIs to identify the macOS version and set the `os.version` system property to that value. The current recommended version to build the JDK on macOS is XCode 15.4. The `NSOperatingSystemVersion` API on that version of XCode reports macOS version as 16 instead of 26.
> 
> The commit in this PR updates the JDK code to handle this mismatch and set the `os.version` appropriately to 26. This fix is similar to what we did with macOS BigSur when the macOS version 10.16 was meant to mean 11 https://bugs.openjdk.org/browse/JDK-8253702. 
> 
> The existing `OsVersionTest` has been updated for some trivial clean up. Existing tests in tier1, tier2 and tier3 continue to pass with this change. If anyone has access to a macOS 26 Beta, I request them to build this change and run `tier1` tests to help verify that there aren't any failures.

LGTM

I tested this on macOS 26. Without this patch `os.version` is set to `16`; with this patch, it is correctly set to `26`.

I left one possible suggestion, if you want to consider it.

src/java.base/macosx/native/libjava/java_props_macosx.c line 242:

> 240:     const bool versionCompatEnabled = envVal != NULL && strncmp(envVal, "1", 1) == 0;
> 241:     const bool requiresSpecialHandling = ((long) osVer.majorVersion == 10 && (long) osVer.minorVersion >= 16)
> 242:                                          || ((long) osVer.majorVersion == 16 && (long) osVer.minorVersion >= 0);

Since we know Apple jumped from 15 --> 26, would it be more future-proof to change this test to something like this?


    osVer.majorVersion >= 16 && osVer.majorVersion < 26 


This would allow us to work when macOS 27 comes out, in case it reports itself as "17.0" if we don't update the version of Xcode before then.

I can also see the argument for leaving it as you have done. And my guess is that Apple will report macOS 27 as 27 regardless, so this probably doesn't matter.

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Marked as reviewed by kcr (Author).

PR Review: https://git.openjdk.org/jdk/pull/25865#pullrequestreview-2939998221
PR Review Comment: https://git.openjdk.org/jdk/pull/25865#discussion_r2155070320