Create @SkylarkConstructor annotation, to annotate certain global-namespace @SkylarkCallable methods as representing constructors of other skylark types.

This change also demonstrates the new pattern on the global Label() constructor.
As an added bonus, it fixes documentation of that constructor. The old documentation used to read "Label.Label(...)" and the new documentation reads "Label(...)".

RELNOTES: None.
PiperOrigin-RevId: 193109338

1 files changed, 12 insertions, 6 deletions

diff --git a/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java b/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
index 334634e3b9..6b614b381b 100644
--- a/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
+++ b/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
@@ -20,6 +20,7 @@ import com.google.devtools.build.docgen.skylark.SkylarkBuiltinMethodDoc;
 import com.google.devtools.build.docgen.skylark.SkylarkJavaMethodDoc;
 import com.google.devtools.build.docgen.skylark.SkylarkModuleDoc;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkConstructor;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkGlobalLibrary;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
@@ -32,7 +33,6 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.ArrayDeque;
 import java.util.Deque;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
@@ -120,10 +120,8 @@ final class SkylarkDocumentationCollector {
       Map<String, SkylarkModuleDoc> modules) {
     Set<Class<?>> done = new HashSet<>();
     Deque<Class<?>> toProcess = new ArrayDeque<>();
-    Map<Class<?>, SkylarkModule> annotations = new HashMap<>();
 
     toProcess.addLast(firstClass);
-    annotations.put(firstClass, firstModule);
 
     while (!toProcess.isEmpty()) {
       Class<?> c = toProcess.removeFirst();
@@ -143,7 +141,6 @@ final class SkylarkDocumentationCollector {
           if (returnClass.isAnnotationPresent(SkylarkModule.class)
               && !done.contains(returnClass)) {
             toProcess.addLast(returnClass);
-            annotations.put(returnClass, returnClass.getAnnotation(SkylarkModule.class));
           }
         }
       }
@@ -165,12 +162,21 @@ final class SkylarkDocumentationCollector {
   private static void collectBuiltinMethods(
       Map<String, SkylarkModuleDoc> modules, Class<?> moduleClass) {
 
-    SkylarkModuleDoc module = getTopLevelModuleDoc(modules);
+    SkylarkModuleDoc topLevelModuleDoc = getTopLevelModuleDoc(modules);
 
     ImmutableMap<Method, SkylarkCallable> methods =
         FuncallExpression.collectSkylarkMethodsWithAnnotation(moduleClass);
     for (Map.Entry<Method, SkylarkCallable> entry : methods.entrySet()) {
-      module.addMethod(new SkylarkJavaMethodDoc("", entry.getKey(), entry.getValue()));
+      if (entry.getKey().isAnnotationPresent(SkylarkConstructor.class)) {
+        SkylarkConstructor constructorAnnotation =
+            entry.getKey().getAnnotation(SkylarkConstructor.class);
+        Class<?> objectClass = constructorAnnotation.objectType();
+        SkylarkModuleDoc module = getSkylarkModuleDoc(objectClass, modules);
+        module.addMethod(
+              new SkylarkJavaMethodDoc("", entry.getKey(), entry.getValue()));
+      } else {
+        topLevelModuleDoc.addMethod(new SkylarkJavaMethodDoc("", entry.getKey(), entry.getValue()));
+      }
     }
   }
 }