8303431: [JVMCI] libgraal annotation API

Reviewed-by: kvn, never, darcy

src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java

@@ -677,6 +677,13 @@ class AnnotationInvocationHandler implements InvocationHandler, Serializable {
         UnsafeAccessor.setMemberValues(this, mv);
     }
 
+    /**
+     * Gets an unmodifiable view on the member values.
+     */
+    Map<String, Object> memberValues() {
+        return Collections.unmodifiableMap(memberValues);
+    }
+
     private static class UnsafeAccessor {
         private static final jdk.internal.misc.Unsafe unsafe
                 = jdk.internal.misc.Unsafe.getUnsafe();

src/java.base/share/classes/sun/reflect/annotation/AnnotationParser.java

@@ -83,14 +83,14 @@ public class AnnotationParser {
      * Like {@link #parseAnnotations(byte[], sun.reflect.ConstantPool, Class)}
      * with an additional parameter {@code selectAnnotationClasses} which selects the
      * annotation types to parse (other than selected are quickly skipped).<p>
-     * This method is only used to parse select meta annotations in the construction
+     * This method is used to parse select meta annotations in the construction
      * phase of {@link AnnotationType} instances to prevent infinite recursion.
      *
      * @param selectAnnotationClasses an array of annotation types to select when parsing
      */
     @SafeVarargs
     @SuppressWarnings("varargs") // selectAnnotationClasses is used safely
-    static Map<Class<? extends Annotation>, Annotation> parseSelectAnnotations(
+    public static Map<Class<? extends Annotation>, Annotation> parseSelectAnnotations(
                 byte[] rawAnnotations,
                 ConstantPool constPool,
                 Class<?> container,
@@ -336,6 +336,8 @@ public class AnnotationParser {
                                           ByteBuffer buf,
                                           ConstantPool constPool,
                                           Class<?> container) {
+        // Note that VMSupport.encodeAnnotation (used by JVMCI) may need to
+        // be updated if new annotation member types are added.
         Object result = null;
         int tag = buf.get();
         switch(tag) {

src/java.base/share/classes/sun/reflect/annotation/AnnotationSupport.java

@@ -281,4 +281,13 @@ public final class AnnotationSupport {
             }
         }
     }
+
+    /**
+     * Gets an unmodifiable view of {@code a}'s elements.
+     *
+     * @return a map from element names to element values
+     */
+    public static Map<String, Object> memberValues(Annotation a) {
+        return ((AnnotationInvocationHandler) Proxy.getInvocationHandler(a)).memberValues();
+    }
 }