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

PullRequest: graal/22060

Author: zapster

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/HijrahChronologyFeature.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.core.jdk;
+
+import java.nio.file.Path;
+import java.time.chrono.HijrahChronology;
+import java.util.Properties;
+
+import com.oracle.svm.core.annotate.Delete;
+import com.oracle.svm.core.annotate.Substitute;
+import com.oracle.svm.core.annotate.TargetClass;
+import com.oracle.svm.core.feature.AutomaticallyRegisteredFeature;
+import com.oracle.svm.core.feature.InternalFeature;
+
+/**
+ * Feature to configure {@link HijrahChronology} at build time. All {@link HijrahChronology} object
+ * that end up in the image heap are fully initialized. This has the advantage that the resources
+ * and files for configuring the {@link HijrahChronology} variants are not needed at run time. On
+ * the other hand, the configuration can no longer be changed after building. See
+ * {@link HijrahChronology} for configuration option.
+ */
+@AutomaticallyRegisteredFeature
+public class HijrahChronologyFeature implements InternalFeature {
+    @Override
+    public void duringSetup(DuringSetupAccess access) {
+        // implicitly initialize HijrahChronology objects via transitive call to checkCalendarInit()
+        access.registerObjectReachabilityHandler(o -> o.isLeapYear(0), HijrahChronology.class);
+    }
+}
+
+@TargetClass(HijrahChronology.class)
+final class Target_java_time_chrono_HijrahChronology {
+    // Checkstyle: stop
+    /**
+     * Config path with includes JAVA_HOME. We force full initialization at build time
+     * {@link HijrahChronologyFeature#duringSetup}, so no need to keep this.
+     */
+    @Delete //
+    private static Path CONF_PATH;
+    // Checkstyle: resume
+
+    /**
+     * @see #CONF_PATH
+     */
+    @Delete
+    private static native void registerCustomChrono();
+
+    /**
+     * @see #CONF_PATH
+     */
+    @Delete
+    private native void loadCalendarData();
+
+    /**
+     * @see #CONF_PATH
+     */
+    @Delete
+    private static native Properties readConfigProperties(String chronologyId, String calendarType);
+
+    /**
+     * @see #CONF_PATH
+     */
+    @Delete //
+    private boolean initComplete;
+
+    /**
+     * No more initialization needed.
+     *
+     * @see #CONF_PATH
+     */
+    @Substitute
+    private void checkCalendarInit() {
+        // initialized at build time
+    }
+}

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/jdk/JDKInitializationFeature.java

@@ -73,7 +73,8 @@ public void afterRegistration(AfterRegistrationAccess access) {
         rci.initializeAtBuildTime("java.nio", JDK_CLASS_REASON);
         rci.initializeAtBuildTime("java.text", JDK_CLASS_REASON);
         rci.initializeAtBuildTime("java.time", JDK_CLASS_REASON);
-        rci.initializeAtRunTime("java.time.chrono.HijrahChronology", "Reads java.home in class initializer.");
+        // see HijrahChronologyFeature for more details
+        rci.initializeAtBuildTime("java.time.chrono.HijrahChronology", "Needs to be fully initialized at build time");
         rci.initializeAtBuildTime("java.util", JDK_CLASS_REASON);
         rci.initializeAtRunTime("java.util.concurrent.SubmissionPublisher", "Executor service must be recomputed");