[GR-21741] Fixes support for timezones.

PullRequest: graal/5655

sdk/src/org.graalvm.nativeimage/snapshot.sigtest

@@ -483,6 +483,7 @@ CLSS public abstract interface !annotation org.graalvm.nativeimage.c.function.CL
  anno 0 java.lang.annotation.Target(java.lang.annotation.ElementType[] value=[TYPE, METHOD])
 intf java.lang.annotation.Annotation
 meth public abstract !hasdefault boolean requireStatic()
+meth public abstract !hasdefault java.lang.String[] dependsOn()
 meth public abstract java.lang.String value()
 
 CLSS public abstract interface !annotation org.graalvm.nativeimage.c.function.CMacroInfo

sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/c/function/CLibrary.java

@@ -68,4 +68,11 @@
      * @since 19.1.0
      */
     boolean requireStatic() default false;
+
+    /**
+     * Specifies the name of the libraries this library depends on.
+     * 
+     * @since 20.1.0
+     */
+    String[] dependsOn() default {};
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/LibCHelper.java

@@ -27,11 +27,16 @@
 import org.graalvm.nativeimage.c.function.CFunction;
 import org.graalvm.nativeimage.c.function.CFunction.Transition;
 import org.graalvm.nativeimage.c.function.CLibrary;
+import org.graalvm.nativeimage.c.type.CCharPointer;
 import org.graalvm.nativeimage.c.type.CCharPointerPointer;
 
-@CLibrary(value = "libchelper", requireStatic = true)
+@CLibrary(value = "libchelper", requireStatic = true, dependsOn = "java")
 public class LibCHelper {
     @CFunction(transition = Transition.NO_TRANSITION)
     public static native CCharPointerPointer getEnviron();
 
+    @CFunction(transition = Transition.TO_NATIVE)
+    // Checkstyle: stop
+    public static native CCharPointer SVM_FindJavaTZmd(CCharPointer tzMappings, int length);
+    // Checkstyle: start
 }

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

@@ -24,84 +24,165 @@
  */
 package com.oracle.svm.core.jdk;
 
-import static java.util.stream.Collectors.toMap;
-
-import java.util.Arrays;
-import java.util.Map;
-import java.util.TimeZone;
-
-import org.graalvm.compiler.options.Option;
-import org.graalvm.nativeimage.hosted.Feature;
-import org.graalvm.nativeimage.ImageSingletons;
-
+import com.oracle.svm.core.LibCHelper;
+import com.oracle.svm.core.OS;
+import com.oracle.svm.core.annotate.Alias;
 import com.oracle.svm.core.annotate.AutomaticFeature;
+import com.oracle.svm.core.annotate.RecomputeFieldValue;
 import com.oracle.svm.core.annotate.Substitute;
+import com.oracle.svm.core.util.VMError;
+import org.graalvm.collections.EconomicMap;
+import org.graalvm.compiler.options.Option;
+import org.graalvm.compiler.options.OptionKey;
+
 import com.oracle.svm.core.annotate.TargetClass;
 import com.oracle.svm.core.option.HostedOptionKey;
+import org.graalvm.nativeimage.ImageSingletons;
+import org.graalvm.nativeimage.PinnedObject;
+import org.graalvm.nativeimage.c.type.CCharPointer;
+import org.graalvm.nativeimage.c.type.CTypeConversion;
+import org.graalvm.nativeimage.hosted.Feature;
+import org.graalvm.word.WordFactory;
 
-final class TimeZoneSupport {
-
-    final Map<String, TimeZone> zones;
-    TimeZone defaultZone;
-
-    TimeZoneSupport(Map<String, TimeZone> zones, TimeZone defaultZone) {
-        this.zones = zones;
-        this.defaultZone = defaultZone;
-    }
-
-    public static TimeZoneSupport instance() {
-        return ImageSingletons.lookup(TimeZoneSupport.class);
-    }
-}
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.TimeZone;
 
+/**
+ * The following classes aim to provide full support for time zones for native-image. This
+ * substitution is necessary due to the reliance on JAVA_HOME in the JDK.
+ *
+ * In summary in the JDK time zone data is extracted from the underlying platform via native
+ * methods, later the JDK code processes that data to create time zone objects exposed via JAVA
+ * APIs.
+ *
+ * Luckily JAVA_HOME is only really necessary for the Windows operating system. Posix operating
+ * systems rely on system calls independent of JAVA_HOME (except for null checks done in the JNI
+ * function wrapping the native time zone JDK functions). Thus for Posix operating systems this
+ * implementation, simply, by-passes the null check(in native image JAVA_HOME is null) and calls
+ * into the original native functions by substituting the JNI method
+ * TimeZone.getSystemTimeZoneID(String).
+ *
+ * In Windows, the JRE contains a special file called tzmappings, (see
+ * <a href="https://docs.oracle.com/javase/9/troubleshoot/time-zone-settings-jre.htm#JSTGD359">time
+ * zones in the jre</a>), representing the mapping between Windows and Java time zones. The
+ * tzmappings file is read and parsed in the native JDK code. Thus for windows,
+ * {@link TimeZoneFeature} reads such file and stores it in the image heap at build-time. At
+ * run-time the contents of the file are passed to a custom implementation of the JDK time zones
+ * logic. The only difference in the custom implementation is reading and parsing time zone mappings
+ * from a buffer as opposed to a file.
+ */
 @TargetClass(java.util.TimeZone.class)
+@SuppressWarnings("unused")
 final class Target_java_util_TimeZone {
 
+    @Alias @RecomputeFieldValue(kind = RecomputeFieldValue.Kind.Reset) private static TimeZone defaultTimeZone;
+
     @Substitute
-    private static TimeZone getDefaultRef() {
-        return TimeZoneSupport.instance().defaultZone;
+    private static String getSystemTimeZoneID(String javaHome) {
+        CCharPointer tzMappingsPtr = WordFactory.nullPointer();
+        int contentLen = 0;
+        PinnedObject pinnedContent = null;
+        try {
+            if (ImageSingletons.contains(TimeZoneSupport.class)) {
+                byte[] content = ImageSingletons.lookup(TimeZoneSupport.class).getTzMappingsContent();
+                contentLen = content.length;
+                pinnedContent = PinnedObject.create(content);
+                tzMappingsPtr = pinnedContent.addressOfArrayElement(0);
+            }
+            CCharPointer tzId = LibCHelper.SVM_FindJavaTZmd(tzMappingsPtr, contentLen);
+            return CTypeConversion.toJavaString(tzId);
+        } finally {
+            if (pinnedContent != null) {
+                pinnedContent.close();
+            }
+        }
     }
+}
 
-    @Substitute
-    private static void setDefault(TimeZone zone) {
-        TimeZoneSupport.instance().defaultZone = zone;
+/**
+ * Holds time zone mapping data.
+ */
+final class TimeZoneSupport {
+    final byte[] tzMappingsContent;
+
+    TimeZoneSupport(final byte[] content) {
+        this.tzMappingsContent = content;
     }
 
-    @Substitute
-    public static TimeZone getTimeZone(String id) {
-        return TimeZoneSupport.instance().zones.getOrDefault(id, TimeZoneSupport.instance().zones.get("GMT"));
+    public byte[] getTzMappingsContent() {
+        return tzMappingsContent;
     }
 }
 
+/**
+ * Reads time zone mappings data and stores in the image heap, if necessary.
+ */
 @AutomaticFeature
 final class TimeZoneFeature implements Feature {
     static class Options {
-        private static final TimeZone defaultZone = TimeZone.getDefault();
-
         @Option(help = "When true, all time zones will be pre-initialized in the image.")//
-        public static final HostedOptionKey<Boolean> IncludeAllTimeZones = new HostedOptionKey<>(false);
+        public static final HostedOptionKey<Boolean> IncludeAllTimeZones = new HostedOptionKey<Boolean>(false) {
+            @Override
+            protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, Boolean oldValue, Boolean newValue) {
+                super.onValueUpdate(values, oldValue, newValue);
+                printWarning();
+            }
+        };
 
         @Option(help = "The time zones, in addition to the default zone of the host, that will be pre-initialized in the image.")//
-        public static final HostedOptionKey<String[]> IncludeTimeZones = new HostedOptionKey<>(new String[]{"GMT", "UTC", defaultZone.getID()});
+        public static final HostedOptionKey<String> IncludeTimeZones = new HostedOptionKey<String>("") {
+            @Override
+            protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, String oldValue, String newValue) {
+                super.onValueUpdate(values, oldValue, newValue);
+                printWarning();
+            }
+        };
+
+        private static void printWarning() {
+            // Checkstyle: stop
+            System.err.println("-H:IncludeAllTimeZones and -H:IncludeTimeZones are now deprecated. Native-image includes all timezones" +
+                            "by default.");
+            // Checkstyle: resume
+        }
+    }
+
+    private static byte[] cleanCR(byte[] buffer) {
+        byte[] scratch = new byte[buffer.length];
+        int copied = 0;
+        for (byte b : buffer) {
+            if (b == '\r') {
+                continue;
+            }
+            scratch[copied++] = b;
+        }
+        byte[] content = new byte[copied];
+        System.arraycopy(scratch, 0, content, 0, copied);
+        return content;
     }
 
     @Override
     public void afterRegistration(AfterRegistrationAccess access) {
-        final String[] supportedZoneIDs;
-        if (Options.IncludeAllTimeZones.getValue()) {
-            supportedZoneIDs = TimeZone.getAvailableIDs();
-        } else {
-            supportedZoneIDs = Options.IncludeTimeZones.getValue();
+
+        if (OS.getCurrent() != OS.WINDOWS) {
+            return;
+        }
+
+        // read tzmappings on windows
+        Path tzMappingsPath = Paths.get(System.getProperty("java.home"), "lib", "tzmappings");
+        try {
+            byte[] buffer = Files.readAllBytes(tzMappingsPath);
+            // tzmappings has windows line endings on windows??
+            byte[] content = cleanCR(buffer);
+            ImageSingletons.add(TimeZoneSupport.class, new TimeZoneSupport(content));
+        } catch (IOException e) {
+            VMError.shouldNotReachHere("Failed to read time zone mappings. The time zone mappings should be part" +
+                            "of your JDK usually found: " + tzMappingsPath.toAbsolutePath(), e);
         }
-        Map<String, TimeZone> supportedZones = Arrays.stream(supportedZoneIDs)
-                        .map(TimeZone::getTimeZone)
-                        .collect(toMap(TimeZone::getID, tz -> tz, (tz1, tz2) -> tz1));
-        ImageSingletons.add(TimeZoneSupport.class, new TimeZoneSupport(supportedZones, Options.defaultZone));
     }
 }
 
-/**
- * This whole file should be eventually removed: GR-11844.
- */
-public class TimeZoneSubstitutions {
+class TimeZoneSubstitutions {
 }