Make EvalUtils.getDataTypeNameFromClass() look for @SkylarkModules in parent classes

This is needed to let subclasses of @SkylarkModules have the same type() string as their superclass, without requiring a second annotation for the subclass.

--
MOS_MIGRATED_REVID=135814343

1 files changed, 39 insertions, 20 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkInterfaceUtils.java b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkInterfaceUtils.java
index 95d4f4fcf5..348a9ccef4 100644
--- a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkInterfaceUtils.java
+++ b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkInterfaceUtils.java
@@ -23,40 +23,59 @@ import javax.annotation.Nullable;
 public class SkylarkInterfaceUtils {
 
   /**
+   * Returns the {@link SkylarkModule} annotation for the given class, if it exists, and
+   * null otherwise. The first annotation found will be returned, starting with {@code classObj}
+   * and following its base classes and interfaces recursively.
+   */
+  @Nullable
+  public static SkylarkModule getSkylarkModule(Class<?> classObj) {
+    if (classObj.isAnnotationPresent(SkylarkModule.class)) {
+      return classObj.getAnnotation(SkylarkModule.class);
+    }
+    Class<?> superclass = classObj.getSuperclass();
+    if (superclass != null) {
+      SkylarkModule annotation = getSkylarkModule(superclass);
+      if (annotation != null) {
+        return annotation;
+      }
+    }
+    for (Class<?> interfaceObj : classObj.getInterfaces()) {
+      SkylarkModule annotation = getSkylarkModule(interfaceObj);
+      if (annotation != null) {
+        return annotation;
+      }
+    }
+    return null;
+  }
+
+  /**
    * Returns the {@link SkylarkCallable} annotation for the given method, if it exists, and
-   * null otherwise. The method must be declared in {@code classObj} or one of its base classes
-   * or interfaces. The first annotation of an overridden version of the method that is found
+   * null otherwise. The first annotation of an overridden version of the method that is found
    * will be returned, starting with {@code classObj} and following its base classes and
-   * interfaces recursively.
+   * interfaces recursively, skipping any annotation inside a class not marked
+   * {@link SkylarkModule}.
    */
   @Nullable
   public static SkylarkCallable getSkylarkCallable(Class<?> classObj, Method method) {
-    boolean keepLooking = false;
     try {
       Method superMethod = classObj.getMethod(method.getName(), method.getParameterTypes());
       if (classObj.isAnnotationPresent(SkylarkModule.class)
           && superMethod.isAnnotationPresent(SkylarkCallable.class)) {
         return superMethod.getAnnotation(SkylarkCallable.class);
-      } else {
-        keepLooking = true;
       }
     } catch (NoSuchMethodException e) {
-      // The class might not have the specified method, so an exceptions is OK.
-      keepLooking = true;
+      // The class might not have the specified method, so an exception is OK.
     }
-    if (keepLooking) {
-      if (classObj.getSuperclass() != null) {
-        SkylarkCallable annotation =
-            getSkylarkCallable(classObj.getSuperclass(), method);
-        if (annotation != null) {
-          return annotation;
-        }
+    if (classObj.getSuperclass() != null) {
+      SkylarkCallable annotation = getSkylarkCallable(classObj.getSuperclass(), method);
+      if (annotation != null) {
+        return annotation;
       }
-      for (Class<?> interfaceObj : classObj.getInterfaces()) {
-        SkylarkCallable annotation = getSkylarkCallable(interfaceObj, method);
-        if (annotation != null) {
-          return annotation;
-        }
+    }
+    for (Class<?> interfaceObj : classObj.getInterfaces()) {
+      SkylarkCallable annotation = getSkylarkCallable(interfaceObj, method);
+      if (annotation != null) {
+        return annotation;
       }
     }
     return null;