Deprecating Extension.optional

Author: jglick

core/src/main/java/hudson/Extension.java

@@ -87,7 +87,10 @@
     /**
      * If an extension is optional, don't log any class loading errors when reading it.
      * @since 1.358
+     * @deprecated This is very difficult to use correctly and rarely what you actually wanted.
+     *             Use {@code OptionalExtension} from the {@code variant} plugin instead.
      */
+    @Deprecated
     boolean optional() default false;
 
     /**

core/src/main/java/hudson/ExtensionFinder.java

@@ -193,6 +193,7 @@ public DefaultGuiceExtensionAnnotation() {
             super(Extension.class);
         }
 
+        @SuppressWarnings("deprecation")
         @Override
         protected boolean isOptional(Extension annotation) {
             return annotation.optional();
@@ -779,6 +780,7 @@ public void scout(Class extensionType, Hudson hudson) {
             }
         }
 
+        @SuppressWarnings("deprecation")
         private Level logLevel(IndexItem<Extension, Object> item) {
             return item.annotation().optional() ? Level.FINE : Level.WARNING;
         }

core/src/main/java/hudson/lifecycle/ExitLifecycle.java

@@ -25,7 +25,6 @@
 package hudson.lifecycle;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
-import hudson.Extension;
 import hudson.util.BootFailure;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -44,7 +43,6 @@
  * @author Alon Bar-Lev
  */
 @Restricted(NoExternalUse.class)
-@Extension
 public class ExitLifecycle extends Lifecycle {
 
     private static final Logger LOGGER = Logger.getLogger(ExitLifecycle.class.getName());

core/src/main/java/hudson/lifecycle/Lifecycle.java

@@ -26,7 +26,6 @@
 
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
-import hudson.ExtensionPoint;
 import hudson.Functions;
 import hudson.PluginManager;
 import hudson.Util;
@@ -62,7 +61,7 @@
  * @author Kohsuke Kawaguchi
  * @since 1.254
  */
-public abstract class Lifecycle implements ExtensionPoint {
+public abstract class Lifecycle {
     private static Lifecycle INSTANCE = null;
 
     /**

core/src/main/java/hudson/lifecycle/SystemdLifecycle.java

@@ -4,7 +4,6 @@
 import com.sun.jna.Native;
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
-import hudson.Extension;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -17,7 +16,6 @@
  * @author Basil Crow
  */
 @Restricted(NoExternalUse.class)
-@Extension(optional = true)
 public class SystemdLifecycle extends ExitLifecycle {
 
     private static final Logger LOGGER = Logger.getLogger(SystemdLifecycle.class.getName());

core/src/main/java/jenkins/diagnosis/HsErrPidList.java

@@ -34,8 +34,7 @@
  *
  * @author Kohsuke Kawaguchi
  */
-@Extension(optional = true) @Symbol("hsErrPid")
-// TODO why would an extension using a built-in extension point need to be marked optional?
+@Extension @Symbol("hsErrPid")
 public class HsErrPidList extends AdministrativeMonitor {
     /**
      * hs_err_pid files that we think belong to us.