[GR-69494] Support for build-time initialization of HijrahChronology in Native Image

[graalvmbot]

HijrahChronology is configured via 1) a default resource shipped with the JDK and 2) via user-supplied properties files dropped into $JAVA_HOME/conf/chronology. This is a challenge for the native image initialization strategy. Currently, we initialize HijrahChronology at run time, which requires the default resource to be registered at build time and -Djava.home= to be set at run time (even if no extra configuration is needed, see #11410). This is not really practical. Instead, this PR makes HijrahChronology build-time initialized and ensures that all required configuration (resources and extra properties files) are read during the build and are no longer needed at run time.

This comes at the cost that HijrahChronology can no longer be configured at run time. On the other hand, dropping properties files into $JAVA_HOME is something that many users cannot do anyways (e.g., because it is read-only), so requiring this to be done at image build time seems like a viable compromise.

• fixes [Native Image] HijrahChronology is broken in native mode #11410
• supersedes Register required resources for HijrahChronology and fix NPE on initialization #11420

[zapster]

cc @Eng-Fouad

[Eng-Fouad]

cc @Eng-Fouad

Thanks for submitting this PR. So, after applying this PR, will users be able to set custom configurations for HijrahChronology (custom hijrah-config-Hijrah-umalqura_islamic-umalqura.properties) at build time?

2. via user-supplied properties files dropped into $JAVA_HOME/conf/chronology

This feature was requested by me to OpenJDK project few years ago and they add it to JDK since JDK15 :)

[zapster]

So, after applying this PR, will users be able to set custom configurations for HijrahChronology (custom hijrah-config-Hijrah-umalqura_islamic-umalqura.properties) at build time?

Exactly. You just need to configure the JVM native image runs on as you would for normal Java execution. So assuming you have a standard GraalVM distribution and the native image command lives in $GRAALVM_HOME/bin/native-image, you would drop the extra config files into $GRAALVM_HOME/conf/chronology.

This feature was requested by me to OpenJDK project few years ago and they add it to JDK since JDK15 :)

😎

[Eng-Fouad]

@zapster Will this be part of GraalVM 25? or 26?

[zapster]

Currently it is only on master, i.e., what potentially becomes GraalVM 26. We might consider backporting to 25, but it won't make it into the initial 25.0.0 release since that is released next week and it is simply to late in the release cycle. But it can be available in a future 25 update release if we decide to backport it.