Throw if @subscribe is applied to a method that takes a primitive parameter.

Fixes #3992.

RELNOTES=Prevent @subscribe being applied to a method that takes a primitive, as that will never be called.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=328195519

Author: netdpb

android/guava-tests/test/com/google/common/eventbus/EventBusTest.java

@@ -289,6 +289,18 @@ public void call(String s) {
     assertEquals(1, calls.get());
   }
 
+  public void testPrimitiveSubscribeFails() {
+    class SubscribesToPrimitive {
+      @Subscribe
+      public void toInt(int i) {}
+    }
+    try {
+      bus.register(new SubscribesToPrimitive());
+      fail("should have thrown");
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
   /** Records thrown exception information. */
   private static final class RecordingSubscriberExceptionHandler
       implements SubscriberExceptionHandler {

android/guava/src/com/google/common/eventbus/Subscribe.java

@@ -23,9 +23,10 @@
 /**
  * Marks a method as an event subscriber.
  *
- * <p>The type of event will be indicated by the method's first (and only) parameter. If this
- * annotation is applied to methods with zero parameters, or more than one parameter, the object
- * containing the method will not be able to register for event delivery from the {@link EventBus}.
+ * <p>The type of event will be indicated by the method's first (and only) parameter, which cannot
+ * be primitive. If this annotation is applied to methods with zero parameters, or more than one
+ * parameter, the object containing the method will not be able to register for event delivery from
+ * the {@link EventBus}.
  *
  * <p>Unless also annotated with @{@link AllowConcurrentEvents}, event subscriber methods will be
  * invoked serially by each event bus that they are registered with.

android/guava/src/com/google/common/eventbus/SubscriberRegistry.java

@@ -16,6 +16,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Throwables.throwIfUnchecked;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
@@ -31,6 +32,7 @@
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Multimap;
+import com.google.common.primitives.Primitives;
 import com.google.common.reflect.TypeToken;
 import com.google.common.util.concurrent.UncheckedExecutionException;
 import com.google.j2objc.annotations.Weak;
@@ -170,7 +172,12 @@ private Multimap<Class<?>, Subscriber> findAllSubscribers(Object listener) {
   }
 
   private static ImmutableList<Method> getAnnotatedMethods(Class<?> clazz) {
-    return subscriberMethodsCache.getUnchecked(clazz);
+    try {
+      return subscriberMethodsCache.getUnchecked(clazz);
+    } catch (UncheckedExecutionException e) {
+      throwIfUnchecked(e.getCause());
+      throw e;
+    }
   }
 
   private static ImmutableList<Method> getAnnotatedMethodsNotCached(Class<?> clazz) {
@@ -183,11 +190,20 @@ private static ImmutableList<Method> getAnnotatedMethodsNotCached(Class<?> clazz
           Class<?>[] parameterTypes = method.getParameterTypes();
           checkArgument(
               parameterTypes.length == 1,
-              "Method %s has @Subscribe annotation but has %s parameters."
+              "Method %s has @Subscribe annotation but has %s parameters. "
                   + "Subscriber methods must have exactly 1 parameter.",
               method,
               parameterTypes.length);
 
+          checkArgument(
+              !parameterTypes[0].isPrimitive(),
+              "@Subscribe method %s's parameter is %s. "
+                  + "Subscriber methods cannot accept primitives. "
+                  + "Consider changing the parameter to %s.",
+              method,
+              parameterTypes[0].getName(),
+              Primitives.wrap(parameterTypes[0]).getSimpleName());
+
           MethodIdentifier ident = new MethodIdentifier(method);
           if (!identifiers.containsKey(ident)) {
             identifiers.put(ident, method);

guava-tests/test/com/google/common/eventbus/EventBusTest.java

@@ -289,6 +289,18 @@ public void call(String s) {
     assertEquals(1, calls.get());
   }
 
+  public void testPrimitiveSubscribeFails() {
+    class SubscribesToPrimitive {
+      @Subscribe
+      public void toInt(int i) {}
+    }
+    try {
+      bus.register(new SubscribesToPrimitive());
+      fail("should have thrown");
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
   /** Records thrown exception information. */
   private static final class RecordingSubscriberExceptionHandler
       implements SubscriberExceptionHandler {

guava/src/com/google/common/eventbus/Subscribe.java

@@ -23,9 +23,10 @@
 /**
  * Marks a method as an event subscriber.
  *
- * <p>The type of event will be indicated by the method's first (and only) parameter. If this
- * annotation is applied to methods with zero parameters, or more than one parameter, the object
- * containing the method will not be able to register for event delivery from the {@link EventBus}.
+ * <p>The type of event will be indicated by the method's first (and only) parameter, which cannot
+ * be primitive. If this annotation is applied to methods with zero parameters, or more than one
+ * parameter, the object containing the method will not be able to register for event delivery from
+ * the {@link EventBus}.
  *
  * <p>Unless also annotated with @{@link AllowConcurrentEvents}, event subscriber methods will be
  * invoked serially by each event bus that they are registered with.

guava/src/com/google/common/eventbus/SubscriberRegistry.java

@@ -16,6 +16,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Throwables.throwIfUnchecked;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
@@ -31,6 +32,7 @@
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Multimap;
+import com.google.common.primitives.Primitives;
 import com.google.common.reflect.TypeToken;
 import com.google.common.util.concurrent.UncheckedExecutionException;
 import com.google.j2objc.annotations.Weak;
@@ -170,7 +172,12 @@ private Multimap<Class<?>, Subscriber> findAllSubscribers(Object listener) {
   }
 
   private static ImmutableList<Method> getAnnotatedMethods(Class<?> clazz) {
-    return subscriberMethodsCache.getUnchecked(clazz);
+    try {
+      return subscriberMethodsCache.getUnchecked(clazz);
+    } catch (UncheckedExecutionException e) {
+      throwIfUnchecked(e.getCause());
+      throw e;
+    }
   }
 
   private static ImmutableList<Method> getAnnotatedMethodsNotCached(Class<?> clazz) {
@@ -183,11 +190,20 @@ private static ImmutableList<Method> getAnnotatedMethodsNotCached(Class<?> clazz
           Class<?>[] parameterTypes = method.getParameterTypes();
           checkArgument(
               parameterTypes.length == 1,
-              "Method %s has @Subscribe annotation but has %s parameters."
+              "Method %s has @Subscribe annotation but has %s parameters. "
                   + "Subscriber methods must have exactly 1 parameter.",
               method,
               parameterTypes.length);
 
+          checkArgument(
+              !parameterTypes[0].isPrimitive(),
+              "@Subscribe method %s's parameter is %s. "
+                  + "Subscriber methods cannot accept primitives. "
+                  + "Consider changing the parameter to %s.",
+              method,
+              parameterTypes[0].getName(),
+              Primitives.wrap(parameterTypes[0]).getSimpleName());
+
           MethodIdentifier ident = new MethodIdentifier(method);
           if (!identifiers.containsKey(ident)) {
             identifiers.put(ident, method);