Reorganize Skylark Reference documentation.

--
MOS_MIGRATED_REVID=126081020

47 files changed, 439 insertions, 216 deletions

diff --git a/src/main/java/com/google/devtools/build/docgen/DocgenConsts.java b/src/main/java/com/google/devtools/build/docgen/DocgenConsts.java
index f1f710944e..610c15c6dd 100644
--- a/src/main/java/com/google/devtools/build/docgen/DocgenConsts.java
+++ b/src/main/java/com/google/devtools/build/docgen/DocgenConsts.java
@@ -42,6 +42,8 @@ public class DocgenConsts {
       "com/google/devtools/build/docgen/templates/skylark-library.vm";
   public static final String SKYLARK_NAV_TEMPLATE =
       "com/google/devtools/build/docgen/templates/skylark-nav.vm";
+  public static final String SKYLARK_MODULE_CATEGORY_TEMPLATE =
+      "com/google/devtools/build/docgen/templates/skylark-category.vm";
 
   public static final String VAR_LEFT_PANEL = "LEFT_PANEL";
 
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 854c3ef82a..2ffb83517b 100644
--- a/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
+++ b/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
@@ -31,6 +31,7 @@ import com.google.devtools.build.lib.rules.java.JavaSkylarkApiProvider;
 import com.google.devtools.build.lib.rules.java.Jvm;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.FuncallExpression;
 import com.google.devtools.build.lib.syntax.MethodLibrary;
@@ -52,8 +53,12 @@ import java.util.TreeMap;
  * A helper class that collects Skylark module documentation.
  */
 final class SkylarkDocumentationCollector {
-  @SkylarkModule(name = "globals",
-      doc = "Objects, functions and modules registered in the global environment.")
+  @SkylarkModule(
+    name = "globals",
+    title = "Globals",
+    category = SkylarkModuleCategory.TOP_LEVEL_TYPE,
+    doc = "Objects, functions and modules registered in the global environment."
+  )
   private static final class TopLevelModule {}
 
   private SkylarkDocumentationCollector() {}
diff --git a/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationProcessor.java b/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationProcessor.java
index a178f64e86..edf80dad68 100644
--- a/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationProcessor.java
+++ b/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationProcessor.java
@@ -16,10 +16,12 @@ package com.google.devtools.build.docgen;
 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.SkylarkModuleCategory;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -35,22 +37,29 @@ public final class SkylarkDocumentationProcessor {
   public static void generateDocumentation(String outputDir, String... clazz) throws IOException,
       BuildEncyclopediaDocException {
     Map<String, SkylarkModuleDoc> modules = SkylarkDocumentationCollector.collectModules(clazz);
-    List<SkylarkModuleDoc> navModules = new ArrayList<>();
 
     // Generate the top level module first in the doc
     SkylarkModuleDoc topLevelModule = modules.remove(
         SkylarkDocumentationCollector.getTopLevelModule().name());
-    topLevelModule.setTitle("Globals");
     writePage(outputDir, topLevelModule);
-    navModules.add(topLevelModule);
+
+    Map<SkylarkModuleCategory, List<SkylarkModuleDoc>> modulesByCategory = new HashMap<>();
+    for (SkylarkModuleCategory c : SkylarkModuleCategory.values()) {
+      modulesByCategory.put(c, new ArrayList<SkylarkModuleDoc>());
+    }
+
+    modulesByCategory.get(topLevelModule.getAnnotation().category()).add(topLevelModule);
 
     for (SkylarkModuleDoc module : modules.values()) {
       if (module.getAnnotation().documented()) {
         writePage(outputDir, module);
-        navModules.add(module);
+        modulesByCategory.get(module.getAnnotation().category()).add(module);
       }
     }
-    writeNavPage(outputDir, navModules);
+    writeCategoryPage(SkylarkModuleCategory.CONFIGURATION_FRAGMENT, outputDir, modulesByCategory);
+    writeCategoryPage(SkylarkModuleCategory.BUILTIN, outputDir, modulesByCategory);
+    writeCategoryPage(SkylarkModuleCategory.PROVIDER, outputDir, modulesByCategory);
+    writeNavPage(outputDir, modulesByCategory.get(SkylarkModuleCategory.TOP_LEVEL_TYPE));
   }
 
   private static void writePage(String outputDir, SkylarkModuleDoc module) throws IOException {
@@ -60,6 +69,18 @@ public final class SkylarkDocumentationProcessor {
     page.write(skylarkDocPath);
   }
 
+  private static void writeCategoryPage(
+      SkylarkModuleCategory category,
+      String outputDir,
+      Map<SkylarkModuleCategory, List<SkylarkModuleDoc>> modules) throws IOException {
+    File skylarkDocPath = new File(String.format("%s/skylark-%s.html",
+        outputDir, category.getTemplateIdentifier()));
+    Page page = TemplateEngine.newPage(DocgenConsts.SKYLARK_MODULE_CATEGORY_TEMPLATE);
+    page.add("category", category);
+    page.add("modules", modules.get(category));
+    page.write(skylarkDocPath);
+  }
+
   private static void writeNavPage(String outputDir, List<SkylarkModuleDoc> navModules)
       throws IOException {
     File navFile = new File(outputDir + "/" + "skylark-nav.html");
diff --git a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkModuleDoc.java b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkModuleDoc.java
index 0e3c42bee6..288eb4084b 100644
--- a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkModuleDoc.java
+++ b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkModuleDoc.java
@@ -34,7 +34,7 @@ public final class SkylarkModuleDoc extends SkylarkDoc {
   private final Map<String, SkylarkBuiltinMethodDoc> builtinMethodMap;
   private ArrayList<SkylarkJavaMethodDoc> javaMethods;
   private TreeMap<String, SkylarkMethodDoc> methodMap;
-  private String title;
+  private final String title;
 
   public SkylarkModuleDoc(SkylarkModule module, Class<?> classObject) {
     this.module = Preconditions.checkNotNull(
@@ -43,7 +43,11 @@ public final class SkylarkModuleDoc extends SkylarkDoc {
     this.builtinMethodMap = new TreeMap<>();
     this.methodMap = new TreeMap<>();
     this.javaMethods = new ArrayList<>();
-    this.title = module.name();
+    if (module.title().isEmpty()) {
+      this.title = module.name();
+    } else {
+      this.title = module.title();
+    }
   }
 
   @Override
@@ -60,10 +64,6 @@ public final class SkylarkModuleDoc extends SkylarkDoc {
     return title;
   }
 
-  public void setTitle(String title) {
-    this.title = title;
-  }
-
   public SkylarkModule getAnnotation() {
     return module;
   }
diff --git a/src/main/java/com/google/devtools/build/docgen/templates/skylark-category.vm b/src/main/java/com/google/devtools/build/docgen/templates/skylark-category.vm
new file mode 100644
index 0000000000..b635e48e7d
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/docgen/templates/skylark-category.vm
@@ -0,0 +1,16 @@
+---
+layout: documentation
+title: ${category.title}
+---
+<h1>${category.title}</h1>
+
+${category.description}
+
+<div class="toc">
+<ul>
+#foreach ($module in $modules)
+
+<li><a href="/docs/skylark/lib/${module.name}.html">${module.title}</a></li>
+#end
+</ul>
+</div>
diff --git a/src/main/java/com/google/devtools/build/docgen/templates/skylark-nav.vm b/src/main/java/com/google/devtools/build/docgen/templates/skylark-nav.vm
index 54194c0c24..46f5d1bb8d 100644
--- a/src/main/java/com/google/devtools/build/docgen/templates/skylark-nav.vm
+++ b/src/main/java/com/google/devtools/build/docgen/templates/skylark-nav.vm
@@ -1,4 +1,6 @@
-#foreach ($module in $modules)
+<li><a href="/docs/skylark/lib/skylark-builtin.html">Builtin Types and Modules</a></li>
+<li><a href="/docs/skylark/lib/skylark-configuration-fragment.html">Configuration fragments</a></li>
+<li><a href="/docs/skylark/lib/skylark-provider.html">Providers</a></li>
+<li><a href="/docs/skylark/lib/globals.html">Globals</a></li>
+<li><a href="/docs/skylark/lib/native.html">Native Module</a></li>
 
-<li><a href="/docs/skylark/lib/${module.name}.html">${module.title}</a></li>
-#end
diff --git a/src/main/java/com/google/devtools/build/lib/actions/Artifact.java b/src/main/java/com/google/devtools/build/lib/actions/Artifact.java
index fe03f57845..bbea1f5ed1 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/Artifact.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/Artifact.java
@@ -28,6 +28,7 @@ import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.shell.ShellUtils;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.syntax.EvalUtils;
 import com.google.devtools.build.lib.syntax.Printer;
@@ -91,6 +92,7 @@ import javax.annotation.Nullable;
  */
 @Immutable
 @SkylarkModule(name = "File",
+    category = SkylarkModuleCategory.BUILTIN,
     doc = "<p>This type represents a file used by the build system. It can be "
         + "either a source file or a derived file produced by a rule.</p>"
         + "<p>The File constructor is private, so you cannot call it directly to create new "
diff --git a/src/main/java/com/google/devtools/build/lib/actions/Root.java b/src/main/java/com/google/devtools/build/lib/actions/Root.java
index b09dfa35c8..a85e95a66a 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/Root.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/Root.java
@@ -17,6 +17,7 @@ package com.google.devtools.build.lib.actions;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
@@ -43,6 +44,7 @@ import javax.annotation.Nullable;
  * that is the root of the merged directory tree.
  */
 @SkylarkModule(name = "root",
+    category = SkylarkModuleCategory.BUILTIN,
     doc = "A root for files. The roots are the directories containing files, and they are mapped "
         + "together into a single directory tree to form the execution environment.")
 public final class Root implements Comparable<Root>, Serializable {
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/FileProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/FileProvider.java
index 0b4dd3b712..9d6e4e173c 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/FileProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/FileProvider.java
@@ -21,6 +21,7 @@ import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 /**
  * A representation of the concept "this transitive info provider builds these files".
@@ -28,7 +29,11 @@ import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
  * <p>Every transitive info collection contains at least this provider.
  */
 @Immutable
-@SkylarkModule(name = "file_provider", doc = "An interface for rules that provide files.")
+@SkylarkModule(
+  name = "file_provider",
+  doc = "An interface for rules that provide files.",
+  category = SkylarkModuleCategory.PROVIDER
+)
 public final class FileProvider implements TransitiveInfoProvider {
   public static final FileProvider EMPTY =
       new FileProvider(NestedSetBuilder.<Artifact>emptySet(Order.STABLE_ORDER));
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
index 35c0b9aa8f..8077a59d35 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
@@ -21,14 +21,13 @@ import com.google.devtools.build.lib.actions.RunfilesSupplier;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 import javax.annotation.Nullable;
 
-/**
- * Returns information about executables produced by a target and the files needed to run it.
- */
+/** Returns information about executables produced by a target and the files needed to run it. */
 @Immutable
-@SkylarkModule(name = "FilesToRunProvider", doc = "")
+@SkylarkModule(name = "FilesToRunProvider", doc = "", category = SkylarkModuleCategory.PROVIDER)
 public final class FilesToRunProvider implements TransitiveInfoProvider {
   /** The name of the field in Skylark used to access this class. */
   public static final String SKYLARK_NAME = "files_to_run";
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java b/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java
index d1f1434a39..0de1b2d513 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java
@@ -32,6 +32,7 @@ import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.packages.BuildType;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
@@ -61,7 +62,11 @@ import javax.annotation.Nullable;
  * manifests" (see {@link PruningManifest}).
  */
 @Immutable
-@SkylarkModule(name = "runfiles", doc = "An interface for a set of runfiles.")
+@SkylarkModule(
+  name = "runfiles",
+  category = SkylarkModuleCategory.NONE,
+  doc = "An interface for a set of runfiles."
+)
 public final class Runfiles {
   private static final Function<SymlinkEntry, Artifact> TO_ARTIFACT =
       new Function<SymlinkEntry, Artifact>() {
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
index ab53315111..6dd8dd7f13 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
@@ -17,26 +17,29 @@ package com.google.devtools.build.lib.analysis;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 import javax.annotation.Nullable;
 
 /**
  * Multiple {@link TransitiveInfoProvider}s bundled together.
  *
- * Represents the information made available by a {@link ConfiguredTarget} to other ones that
- * depend on it. For more information about the analysis phase, see
- * {@link com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory}.
+ * <p>Represents the information made available by a {@link ConfiguredTarget} to other ones that
+ * depend on it. For more information about the analysis phase, see {@link
+ * com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory}.
  *
- * <p>Implementations of build rules should <b>not</b> hold on to references to the
- * {@link TransitiveInfoCollection}s representing their direct prerequisites in order to reduce
- * their memory footprint (otherwise, the referenced object could refer one of its direct
- * dependencies in turn, thereby making the size of the objects reachable from a single instance
- * unbounded).
+ * <p>Implementations of build rules should <b>not</b> hold on to references to the {@link
+ * TransitiveInfoCollection}s representing their direct prerequisites in order to reduce their
+ * memory footprint (otherwise, the referenced object could refer one of its direct dependencies in
+ * turn, thereby making the size of the objects reachable from a single instance unbounded).
  *
  * @see com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory
  * @see TransitiveInfoProvider
  */
-@SkylarkModule(name = "Target", doc =
+@SkylarkModule(
+  name = "Target",
+  category = SkylarkModuleCategory.BUILTIN,
+  doc =
       "A BUILD target. It is essentially a <code>struct</code> with the following fields:"
     + "<ul>"
     + "<li><h3 id=\"modules.Target.label\">label</h3><code><a class=\"anchor\" "
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
index 0499743422..012e72062c 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
@@ -53,6 +53,7 @@ import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.rules.test.TestActionBuilder;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.CPU;
 import com.google.devtools.build.lib.util.Fingerprint;
 import com.google.devtools.build.lib.util.OS;
@@ -108,6 +109,7 @@ import javax.annotation.Nullable;
  * <pre>c1.equals(c2) <=> c1==c2.</pre>
  */
 @SkylarkModule(name = "configuration",
+    category = SkylarkModuleCategory.BUILTIN,
     doc = "Data required for the analysis of a target that comes from targets that "
         + "depend on it and not targets that it depends on.")
 public final class BuildConfiguration {
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
index 3fdd4c8e0a..fb1f4adcf7 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
@@ -19,6 +19,7 @@ import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.ClassObject;
 
 import javax.annotation.Nullable;
@@ -28,7 +29,9 @@ import javax.annotation.Nullable;
  */
 // Documentation can be found at ctx.fragments
 @Immutable
-@SkylarkModule(name = "fragments", doc = "Possible fields are "
+@SkylarkModule(name = "fragments",
+    category = SkylarkModuleCategory.NONE,
+    doc = "Possible fields are "
     + "<a href=\"apple.html\">apple</a>, <a href=\"cpp.html\">cpp</a>, "
     + "<a href=\"java.html\">java</a>, <a href=\"jvm.html\">jvm</a> and "
     + "<a href=\"objc.html\">objc</a>. "
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
index ad2e7b60a8..d306a52d4a 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
@@ -21,6 +21,7 @@ import com.google.devtools.build.lib.shell.CommandException;
 import com.google.devtools.build.lib.shell.CommandResult;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.util.Preconditions;
 
@@ -37,6 +38,7 @@ import java.util.Map;
  */
 @SkylarkModule(
   name = "exec_result",
+  category = SkylarkModuleCategory.NONE,
   doc =
       "A structure storing result of repository_ctx.execute() method. It contains the standard"
           + " output stream content, the standard error stream content and the execution return"
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkOS.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkOS.java
index 05ba5cdc44..2c45c8e697 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkOS.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkOS.java
@@ -18,15 +18,15 @@ import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 import java.util.Map;
 
-/**
- * A Skylark structure to deliver information about the system we are running on.
- */
+/** A Skylark structure to deliver information about the system we are running on. */
 @Immutable
 @SkylarkModule(
   name = "repository_os",
+  category = SkylarkModuleCategory.NONE,
   doc = "Various data about the current platform Bazel is running on."
 )
 final class SkylarkOS {
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java
index 3e29c7048e..cadadec95d 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java
@@ -18,6 +18,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.vfs.Path;
 
 import java.io.IOException;
@@ -30,7 +31,10 @@ import java.util.List;
  * something other than a SkylarkRepositoryContext.
  */
 @Immutable
-@SkylarkModule(name = "path", doc = "A structure representing a file to be used inside a repository"
+@SkylarkModule(
+  name = "path",
+  category = SkylarkModuleCategory.NONE,
+  doc = "A structure representing a file to be used inside a repository"
 )
 final class SkylarkPath {
   private final Path path;
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java
index ec6a353c9a..ad2290adb6 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java
@@ -32,6 +32,7 @@ import com.google.devtools.build.lib.skyframe.InconsistentFilesystemException;
 import com.google.devtools.build.lib.skyframe.PackageLookupValue;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.syntax.Runtime;
@@ -53,11 +54,10 @@ import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
 
-/**
- * Skylark API for the repository_rule's context.
- */
+/** Skylark API for the repository_rule's context. */
 @SkylarkModule(
   name = "repository_ctx",
+  category = SkylarkModuleCategory.BUILTIN,
   doc =
       "The context of the repository rule containing"
           + " helper functions and information about attributes. You get a repository_ctx object"
diff --git a/src/main/java/com/google/devtools/build/lib/cmdline/Label.java b/src/main/java/com/google/devtools/build/lib/cmdline/Label.java
index 75d4677365..19f346f48b 100644
--- a/src/main/java/com/google/devtools/build/lib/cmdline/Label.java
+++ b/src/main/java/com/google/devtools/build/lib/cmdline/Label.java
@@ -22,6 +22,7 @@ import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrintableValue;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.util.StringCanonicalizer;
@@ -34,15 +35,20 @@ import java.io.ObjectInputStream;
 import java.io.Serializable;
 
 /**
- * A class to identify a BUILD target. All targets belong to exactly one package.
- * The name of a target is called its label. A typical label looks like this:
- * //dir1/dir2:target_name where 'dir1/dir2' identifies the package containing a BUILD file,
- * and 'target_name' identifies the target within the package.
+ * A class to identify a BUILD target. All targets belong to exactly one package. The name of a
+ * target is called its label. A typical label looks like this: //dir1/dir2:target_name where
+ * 'dir1/dir2' identifies the package containing a BUILD file, and 'target_name' identifies the
+ * target within the package.
  *
  * <p>Parsing is robust against bad input, for example, from the command line.
  */
-@SkylarkModule(name = "Label", doc = "A BUILD target identifier.")
-@Immutable @ThreadSafe
+@SkylarkModule(
+  name = "Label",
+  category = SkylarkModuleCategory.BUILTIN,
+  doc = "A BUILD target identifier."
+)
+@Immutable
+@ThreadSafe
 public final class Label implements Comparable<Label>, Serializable, SkylarkPrintableValue {
   public static final PathFragment EXTERNAL_PACKAGE_NAME = new PathFragment("external");
   public static final PathFragment EXTERNAL_PACKAGE_FILE_NAME = new PathFragment("WORKSPACE");
diff --git a/src/main/java/com/google/devtools/build/lib/packages/Attribute.java b/src/main/java/com/google/devtools/build/lib/packages/Attribute.java
index 7e8cfffec5..5d4fe22386 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Attribute.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Attribute.java
@@ -26,6 +26,7 @@ import com.google.common.collect.Sets;
 import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.ClassObject;
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.syntax.EvalException;
@@ -163,10 +164,11 @@ public final class Attribute implements Comparable<Attribute> {
   }
 
   /**
-   * Declaration how the configuration should change when following a label or
-   * label list attribute.
+   * Declaration how the configuration should change when following a label or label list attribute.
    */
-  @SkylarkModule(name = "ConfigurationTransition", doc =
+  @SkylarkModule(name = "ConfigurationTransition",
+    category = SkylarkModuleCategory.NONE,
+    doc =
       "Declares how the configuration should change when following a dependency. "
     + "It can be either <a href=\"globals.html#DATA_CFG\">DATA_CFG</a> or "
     + "<a href=\"globals.html#HOST_CFG\">HOST_CFG</a>.")
diff --git a/src/main/java/com/google/devtools/build/lib/packages/SkylarkAspect.java b/src/main/java/com/google/devtools/build/lib/packages/SkylarkAspect.java
index 625785de59..1a785092b4 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/SkylarkAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/SkylarkAspect.java
@@ -19,6 +19,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.syntax.BaseFunction;
 import com.google.devtools.build.lib.syntax.Environment;
@@ -29,15 +30,15 @@ import com.google.devtools.build.lib.util.Preconditions;
 
 import javax.annotation.Nullable;
 
-/**
- * A Skylark value that is a result of an 'aspect(..)' function call.
- */
+/** A Skylark value that is a result of an 'aspect(..)' function call. */
 @SkylarkModule(
   name = "Aspect",
+  category = SkylarkModuleCategory.NONE,
   doc =
       "For more information about Aspects, please consult the <a href=\"globals.html#aspect\">"
           + "documentation of the aspect function</a> or the "
-          + "<a href=\"../aspects.md\">introduction to Aspects</a>.")
+          + "<a href=\"../aspects.md\">introduction to Aspects</a>."
+)
 public class SkylarkAspect implements SkylarkValue {
   private final BaseFunction implementation;
   private final ImmutableList<String> attributeAspects;
diff --git a/src/main/java/com/google/devtools/build/lib/packages/SkylarkNativeModule.java b/src/main/java/com/google/devtools/build/lib/packages/SkylarkNativeModule.java
index 31208ba212..190a46b327 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/SkylarkNativeModule.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/SkylarkNativeModule.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.packages;
 
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.BuiltinFunction;
 import com.google.devtools.build.lib.syntax.Environment;
@@ -30,7 +31,10 @@ import com.google.devtools.build.lib.syntax.Type.ConversionException;
 /**
  * A class for the Skylark native module.
  */
-@SkylarkModule(name = "native", namespace = true, doc =
+@SkylarkModule(name = "native", namespace = true,
+    title = "Native Module",
+    category = SkylarkModuleCategory.TOP_LEVEL_TYPE,
+    doc =
     "A built-in module to support native rules and other package helper functions. "
     + "All native rules appear as functions in this module, e.g. <code>native.cc_library</code>. "
     + "Note that the native module is only available in the loading phase "
@@ -46,11 +50,11 @@ public class SkylarkNativeModule {
     returnType = SkylarkList.class,
     doc =
         "Glob returns a list of every file in the current package that:<ul>\n"
-            + "<li>Matches at least one pattern in <code>include</code>.</li>\n"
-            + "<li>Does not match any of the patterns in <code>exclude</code> "
-            + "(default <code>[]</code>).</li></ul>\n"
-            + "If the <code>exclude_directories</code> argument is enabled (set to <code>1</code>),"
-            + " files of type directory will be omitted from the results (default <code>1</code>).",
+        + "<li>Matches at least one pattern in <code>include</code>.</li>\n"
+        + "<li>Does not match any of the patterns in <code>exclude</code> "
+        + "(default <code>[]</code>).</li></ul>\n"
+        + "If the <code>exclude_directories</code> argument is enabled (set to <code>1</code>),"
+        + " files of type directory will be omitted from the results (default <code>1</code>).",
     parameters = {
       @Param(
         name = "include",
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkAttr.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkAttr.java
index 7038b43424..5b0fd57988 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkAttr.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkAttr.java
@@ -26,6 +26,7 @@ import com.google.devtools.build.lib.packages.BuildType;
 import com.google.devtools.build.lib.packages.SkylarkAspect;
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.BuiltinFunction;
 import com.google.devtools.build.lib.syntax.Environment;
@@ -54,13 +55,14 @@ import javax.annotation.Nullable;
 /**
  * A helper class to provide Attr module in Skylark.
  *
- * <p>It exposes functions (e.g. 'attr.string', 'attr.label_list', etc.) to Skylark
- * users. The functions are executed through reflection. As everywhere in Skylark,
- * arguments are type-checked with the signature and cannot be null.
+ * <p>It exposes functions (e.g. 'attr.string', 'attr.label_list', etc.) to Skylark users. The
+ * functions are executed through reflection. As everywhere in Skylark, arguments are type-checked
+ * with the signature and cannot be null.
  */
 @SkylarkModule(
   name = "attr",
   namespace = true,
+  category = SkylarkModuleCategory.BUILTIN,
   doc =
       "Module for creating new attributes. "
           + "They are only for use with the <a href=\"globals.html#rule\">rule</a> function."
@@ -1054,9 +1056,14 @@ public final class SkylarkAttr {
         }
       };
 
-  /**
-   * A descriptor of an attribute defined in Skylark.
-   */
+  /** A descriptor of an attribute defined in Skylark. */
+  @SkylarkModule(
+    name = "attr_defintion",
+    category = SkylarkModuleCategory.NONE,
+    doc =
+        "Representation of a definition of an attribute; cobnstructed by <code>attr.*</code>"
+            + " functions."
+  )
   public static final class Descriptor {
     private final Attribute.Builder<?> attributeBuilder;
     private final ImmutableList<SkylarkAspect> aspects;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkCommandLine.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkCommandLine.java
index 8e107b93a3..7fd5fe4dc4 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkCommandLine.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkCommandLine.java
@@ -20,6 +20,7 @@ import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.BuiltinFunction;
 import com.google.devtools.build.lib.syntax.Environment;
@@ -27,11 +28,13 @@ import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
 import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
 import com.google.devtools.build.lib.syntax.SkylarkSignatureProcessor;
 
-/**
- * A Skylark module class to create memory efficient command lines.
- */
-@SkylarkModule(name = "cmd_helper", namespace = true,
-    doc = "Module for creating memory efficient command lines.")
+/** A Skylark module class to create memory efficient command lines. */
+@SkylarkModule(
+  name = "cmd_helper",
+  namespace = true,
+  category = SkylarkModuleCategory.BUILTIN,
+  doc = "Module for creating memory efficient command lines."
+)
 public class SkylarkCommandLine {
 
   @SkylarkSignature(name = "join_paths", objectType = SkylarkCommandLine.class,
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkFileType.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkFileType.java
index 94ca4c8b5a..6b31fd8761 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkFileType.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkFileType.java
@@ -18,17 +18,20 @@ import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.FileType;
 import com.google.devtools.build.lib.util.FileTypeSet;
 
 import java.util.List;
 
-/**
- * A wrapper class for FileType and FileTypeSet functionality in Skylark.
- */
-@SkylarkModule(name = "FileType",
-    doc = "Deprecated. File type for file filtering. Can be used to filter collections of labels "
-    + "for certain file types.")
+/** A wrapper class for FileType and FileTypeSet functionality in Skylark. */
+@SkylarkModule(
+  name = "FileType",
+  category = SkylarkModuleCategory.NONE,
+  doc =
+      "Deprecated. File type for file filtering. Can be used to filter collections of labels "
+          + "for certain file types."
+)
 public class SkylarkFileType {
 
   private final FileType fileType;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java
index 5c5baba790..a956e4d467 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java
@@ -46,6 +46,7 @@ import com.google.devtools.build.lib.shell.ShellUtils;
 import com.google.devtools.build.lib.shell.ShellUtils.TokenizationException;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.syntax.FuncallExpression.FuncallException;
@@ -69,13 +70,16 @@ import java.util.Set;
 
 import javax.annotation.Nullable;
 
-/**
- * A Skylark API for the ruleContext.
- */
-@SkylarkModule(name = "ctx", doc = "The context of the rule containing helper functions and "
-    + "information about attributes, depending targets and outputs. "
-    + "You get a ctx object as an argument to the <code>implementation</code> function when "
-    + "you create a rule.")
+/** A Skylark API for the ruleContext. */
+@SkylarkModule(
+  name = "ctx",
+  category = SkylarkModuleCategory.BUILTIN,
+  doc =
+      "The context of the rule containing helper functions and "
+          + "information about attributes, depending targets and outputs. "
+          + "You get a ctx object as an argument to the <code>implementation</code> function when "
+          + "you create a rule."
+)
 public final class SkylarkRuleContext {
 
   private static final String DOC_NEW_FILE_TAIL = "Does not actually create a file on the file "
@@ -330,6 +334,7 @@ public final class SkylarkRuleContext {
 
   @SkylarkModule(
     name = "rule_attributes",
+    category = SkylarkModuleCategory.NONE,
     doc = "Information about attributes of a rule an aspect is applied to."
   )
   private static class SkylarkRuleAttributesCollection {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java
index e64bc92f61..ed8434de93 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java
@@ -27,17 +27,21 @@ import com.google.devtools.build.lib.rules.java.JavaRuleOutputJarsProvider;
 import com.google.devtools.build.lib.rules.java.JavaRuleOutputJarsProvider.OutputJar;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 import javax.annotation.Nullable;
 
 /**
- * A class that exposes the Android providers to Skylark. It is intended to provide a
- * simple and stable interface for Skylark users.
+ * A class that exposes the Android providers to Skylark. It is intended to provide a simple and
+ * stable interface for Skylark users.
  */
 @SkylarkModule(
   name = "AndroidSkylarkApiProvider",
-  doc = "Provides access to information about Android rules. Every Android-related target provides "
-  + "this struct, accessible as a 'java' field on a Target struct."
+  title = "android",
+  category = SkylarkModuleCategory.PROVIDER,
+  doc =
+      "Provides access to information about Android rules. Every Android-related target provides "
+          + "this struct, accessible as a 'android' field on a Target struct."
 )
 public class AndroidSkylarkApiProvider extends SkylarkApiProvider {
   /** The name of the field in Skylark used to access this class. */
@@ -148,12 +152,11 @@ public class AndroidSkylarkApiProvider extends SkylarkApiProvider {
                 })));
   }
 
-  /**
-   * Helper class to provide information about IDLs related to this rule.
-   */
+  /** Helper class to provide information about IDLs related to this rule. */
   @SkylarkModule(
-      name = "AndroidSkylarkIdlInfo",
-      doc = "Provides access to information about Android rules"
+    name = "AndroidSkylarkIdlInfo",
+    category = SkylarkModuleCategory.NONE,
+    doc = "Provides access to information about Android rules"
   )
   public class IdlInfo {
     @SkylarkCallable(
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/AppleConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/apple/AppleConfiguration.java
index ebc8c9831f..c8fe054b50 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/AppleConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/AppleConfiguration.java
@@ -32,6 +32,7 @@ import com.google.devtools.build.lib.rules.apple.AppleCommandLineOptions.AppleBi
 import com.google.devtools.build.lib.rules.apple.Platform.PlatformType;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 
 import java.util.ArrayList;
@@ -41,10 +42,12 @@ import java.util.Map;
 
 import javax.annotation.Nullable;
 
-/**
- * A configuration containing flags required for Apple platforms and tools.
- */
-@SkylarkModule(name = "apple", doc = "A configuration fragment for Apple platforms")
+/** A configuration containing flags required for Apple platforms and tools. */
+@SkylarkModule(
+  name = "apple",
+  doc = "A configuration fragment for Apple platforms",
+  category = SkylarkModuleCategory.CONFIGURATION_FRAGMENT
+)
 @Immutable
 public class AppleConfiguration extends BuildConfiguration.Fragment {
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java b/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java
index ebd22f4146..7d97b502d3 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java
@@ -21,6 +21,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Ordering;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 import java.util.ArrayList;
 import java.util.Objects;
@@ -36,8 +37,7 @@ import java.util.regex.Pattern;
  *
  * <p>Dotted versions are ordered using natural integer sorting on components in order from first to
  * last where any missing element is considered to have the value 0 if they don't contain any
- * non-numeric characters. For example:
- * <pre>
+ * non-numeric characters. For example: <pre>
  *   3.1.25 > 3.1.1
  *   3.1.20 > 3.1.2
  *   3.1.1 > 3.1
@@ -50,8 +50,7 @@ import java.util.regex.Pattern;
  * component with a smaller integer. If the integers are the same, the alphabetic sequences are
  * compared lexicographically, and if <i>they</i> turn out to be the same, the final (optional)
  * integer is compared. As with the leading integer, this final integer is considered to be 0 if not
- * present. For example:
- * <pre>
+ * present. For example: <pre>
  *   3.1.1 > 3.1.1beta3
  *   3.1.1beta1 > 3.1.0
  *   3.1 > 3.1.0alpha1
@@ -66,8 +65,10 @@ import java.util.regex.Pattern;
  */
 @SkylarkModule(
   name = "DottedVersion",
-  doc = "A value representing a version with multiple components, seperated by periods, such as "
-      + "1.2.3.4."
+  category = SkylarkModuleCategory.NONE,
+  doc =
+      "A value representing a version with multiple components, seperated by periods, such as "
+          + "1.2.3.4."
 )
 public final class DottedVersion implements Comparable<DottedVersion> {
   private static final Splitter DOT_SPLITTER = Splitter.on('.');
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/Platform.java b/src/main/java/com/google/devtools/build/lib/rules/apple/Platform.java
index 7a8b1d1990..987c4fd0ef 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/Platform.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/Platform.java
@@ -17,6 +17,7 @@ package com.google.devtools.build.lib.rules.apple;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 
 import java.util.Locale;
@@ -24,10 +25,12 @@ import java.util.Set;
 
 import javax.annotation.Nullable;
 
-/**
- * An enum that can be used to distinguish between various apple platforms.
- */
-@SkylarkModule(name = "platform", doc = "Distinguishes between various apple platforms.")
+/** An enum that can be used to distinguish between various apple platforms. */
+@SkylarkModule(
+  name = "platform",
+  category = SkylarkModuleCategory.NONE,
+  doc = "Distinguishes between various apple platforms."
+)
 public enum Platform {
 
   IOS_DEVICE("iPhoneOS", PlatformType.IOS),
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcSkylarkApiProvider.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcSkylarkApiProvider.java
index 4f250b7b18..cd5f64282b 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcSkylarkApiProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcSkylarkApiProvider.java
@@ -21,16 +21,21 @@ import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.rules.SkylarkApiProvider;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.vfs.PathFragment;
 
 /**
- * A class that exposes the C++ providers to Skylark. It is intended to provide a
- * simple and stable interface for Skylark users.
+ * A class that exposes the C++ providers to Skylark. It is intended to provide a simple and stable
+ * interface for Skylark users.
  */
 @SkylarkModule(
-    name = "CcSkylarkApiProvider", doc = "Provides access to information about C++ rules.  "
-    + "Every C++-related target provides this struct, accessible as a 'cc' field on "
-    + "a Target struct.")
+  name = "CcSkylarkApiProvider",
+  category = SkylarkModuleCategory.PROVIDER,
+  doc =
+      "Provides access to information about C++ rules.  "
+          + "Every C++-related target provides this struct, accessible as a 'cc' field on "
+          + "a Target struct."
+)
 public final class CcSkylarkApiProvider extends SkylarkApiProvider {
   /** The name of the field in Skylark used to access this class. */
   public static final String NAME = "cc";
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
index 9889401014..0d5d16430a 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
@@ -40,6 +40,7 @@ import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.rules.cpp.CppConfigurationLoader.CppConfigurationParameters;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
@@ -60,12 +61,15 @@ import java.util.Map;
 import java.util.Set;
 
 /**
- * This class represents the C/C++ parts of the {@link BuildConfiguration},
- * including the host architecture, target architecture, compiler version, and
- * a standard library version. It has information about the tools locations and
- * the flags required for compiling.
+ * This class represents the C/C++ parts of the {@link BuildConfiguration}, including the host
+ * architecture, target architecture, compiler version, and a standard library version. It has
+ * information about the tools locations and the flags required for compiling.
  */
-@SkylarkModule(name = "cpp", doc = "A configuration fragment for C++")
+@SkylarkModule(
+  name = "cpp",
+  doc = "A configuration fragment for C++",
+  category = SkylarkModuleCategory.CONFIGURATION_FRAGMENT
+)
 @Immutable
 public class CppConfiguration extends BuildConfiguration.Fragment {
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationInfoProvider.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationInfoProvider.java
index 76750e72ea..7a577eca27 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationInfoProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationInfoProvider.java
@@ -21,12 +21,14 @@ import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 /**
  * A class that provides compilation information in Java rules, for perusal of aspects and tools.
  */
 @SkylarkModule(
-  name = "JavaCompilationInfo",
+  name = "java_compilation_info",
+  category = SkylarkModuleCategory.NONE,
   doc = "Provides access to compilation information for Java rules"
 )
 @Immutable
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaConfiguration.java
index 8036b9cd2b..27f7d52443 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaConfiguration.java
@@ -28,17 +28,20 @@ import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.common.options.TriState;
 
 import java.util.List;
 
 import javax.annotation.Nullable;
 
-/**
- * A java compiler configuration containing the flags required for compilation.
- */
+/** A java compiler configuration containing the flags required for compilation. */
 @Immutable
-@SkylarkModule(name = "java", doc = "A java compiler configuration")
+@SkylarkModule(
+  name = "java",
+  doc = "A java compiler configuration",
+  category = SkylarkModuleCategory.CONFIGURATION_FRAGMENT
+)
 public final class JavaConfiguration extends Fragment {
   /**
    * Values for the --experimental_java_classpath option
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaGenJarsProvider.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaGenJarsProvider.java
index c676b2243f..12cd42f15f 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaGenJarsProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaGenJarsProvider.java
@@ -20,15 +20,15 @@ import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 import javax.annotation.Nullable;
 
-/**
- * The collection of gen jars from the transitive closure.
- */
+/** The collection of gen jars from the transitive closure. */
 @Immutable
 @SkylarkModule(
-  name = "JavaAnnotationProcessing",
+  name = "java_annotation-processing",
+  category = SkylarkModuleCategory.NONE,
   doc = "Information about jars that are a result of annotation processing for a Java rule."
 )
 public final class JavaGenJarsProvider implements TransitiveInfoProvider {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuleOutputJarsProvider.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuleOutputJarsProvider.java
index 11d16fd2e8..3cbcf252fc 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuleOutputJarsProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuleOutputJarsProvider.java
@@ -20,25 +20,27 @@ import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 
 import javax.annotation.Nullable;
 
-/**
- * Provides information about jar files produced by a Java rule.
- */
+/** Provides information about jar files produced by a Java rule. */
 @Immutable
-@SkylarkModule(name = "JavaOutputJars", doc = "Information about outputs of a Java rule")
+@SkylarkModule(
+  name = "java_output_jars",
+  category = SkylarkModuleCategory.NONE,
+  doc = "Information about outputs of a Java rule"
+)
 public final class JavaRuleOutputJarsProvider implements TransitiveInfoProvider {
 
   public static final JavaRuleOutputJarsProvider EMPTY =
       new JavaRuleOutputJarsProvider(ImmutableList.<OutputJar>of(), null);
 
-  /**
-   * A collection of artifacts associated with a jar output.
-   */
+  /** A collection of artifacts associated with a jar output. */
   @SkylarkModule(
-    name = "JavaOutput",
+    name = "java_output",
+    category = SkylarkModuleCategory.NONE,
     doc = "Java classes jar, together with their associated source and interface archives"
   )
   @Immutable
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiProvider.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiProvider.java
index eb6e7fa89e..6d5f353646 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiProvider.java
@@ -22,15 +22,20 @@ import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.rules.SkylarkApiProvider;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 
 /**
- * A class that exposes the Java providers to Skylark. It is intended to provide a
- * simple and stable interface for Skylark users.
+ * A class that exposes the Java providers to Skylark. It is intended to provide a simple and stable
+ * interface for Skylark users.
  */
 @SkylarkModule(
-    name = "JavaSkylarkApiProvider",
-    doc = "Provides access to information about Java rules. Every Java-related target provides "
-    + "this struct, accessible as a 'java' field on a Target struct.")
+  name = "JavaSkylarkApiProvider",
+  title = "java",
+  category = SkylarkModuleCategory.PROVIDER,
+  doc =
+      "Provides access to information about Java rules. Every Java-related target provides "
+          + "this struct, accessible as a 'java' field on a Target struct."
+)
 public final class JavaSkylarkApiProvider extends SkylarkApiProvider {
   /** The name of the field in Skylark used to access this class. */
   public static final String NAME = "java";
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java b/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java
index edecece6aa..37271b8b48 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java
@@ -20,17 +20,21 @@ import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.OsUtils;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.PathFragment;
 
 /**
- * This class represents a Java virtual machine with a host system and a path.
- * If the JVM comes from the client, it can optionally also contain a label
- * pointing to a target that contains all the necessary files.
+ * This class represents a Java virtual machine with a host system and a path. If the JVM comes from
+ * the client, it can optionally also contain a label pointing to a target that contains all the
+ * necessary files.
  */
-@SkylarkModule(name = "jvm",
-    doc = "A configuration fragment representing the Java virtual machine.")
+@SkylarkModule(
+  name = "jvm",
+  category = SkylarkModuleCategory.CONFIGURATION_FRAGMENT,
+  doc = "A configuration fragment representing the Java virtual machine."
+)
 @Immutable
 public final class Jvm extends BuildConfiguration.Fragment {
   private final PathFragment javaHome;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
index 69596dd723..8da579bde8 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
@@ -24,15 +24,18 @@ import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.rules.apple.DottedVersion;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.Path;
 
 import javax.annotation.Nullable;
 
-/**
- * A compiler configuration containing flags required for Objective-C compilation.
- */
-@SkylarkModule(name = "objc", doc = "A configuration fragment for Objective-C")
+/** A compiler configuration containing flags required for Objective-C compilation. */
+@SkylarkModule(
+  name = "objc",
+  category = SkylarkModuleCategory.CONFIGURATION_FRAGMENT,
+  doc = "A configuration fragment for Objective-C"
+)
 @Immutable
 public class ObjcConfiguration extends BuildConfiguration.Fragment {
   @VisibleForTesting
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
index d16f80bf64..7bf91b8353 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
@@ -29,6 +29,7 @@ import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.rules.cpp.CppModuleMap;
 import com.google.devtools.build.lib.rules.cpp.LinkerInputs;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.syntax.EvalUtils;
 import com.google.devtools.build.lib.util.Preconditions;
@@ -43,7 +44,11 @@ import java.util.Map;
  * deps that are needed for building Objective-C rules.
  */
 @Immutable
-@SkylarkModule(name = "ObjcProvider", doc = "A provider for compilation and linking of objc.")
+@SkylarkModule(
+  name = "ObjcProvider",
+  category = SkylarkModuleCategory.PROVIDER,
+  doc = "A provider for compilation and linking of objc."
+)
 public final class ObjcProvider extends SkylarkClassObject implements TransitiveInfoProvider {
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModule.java b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModule.java
index 0d9d63d1ac..d6ff2351f6 100644
--- a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModule.java
+++ b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModule.java
@@ -30,12 +30,16 @@ public @interface SkylarkModule {
 
   String name();
 
+  String title() default "";
+
   String doc();
 
   boolean documented() default true;
 
   boolean namespace() default false;
 
+  SkylarkModuleCategory category() default SkylarkModuleCategory.TOP_LEVEL_TYPE;
+
   /** Helper method to quickly get the SkylarkModule name of a class (if present). */
   public static final class Resolver {
     /**
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModuleCategory.java b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModuleCategory.java
new file mode 100644
index 0000000000..9602556ad7
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkModuleCategory.java
@@ -0,0 +1,64 @@
+// Copyright 2016 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.skylarkinterface;
+
+/** A category of a Java type exposed to Skylark */
+public enum SkylarkModuleCategory {
+  CONFIGURATION_FRAGMENT("Configuration Fragments",
+      "Configuration fragments give rules access to "
+      + "language-specific parts of <a href=\"/docs/skylark/lib/configuration.html\">"
+      + "configuration</a>. "
+      + "<p>Rule implementations can get them using "
+      + "<code><a href=\"/docs/skylark/lib/ctx.html\">ctx</a>."
+      + "fragments.<i>[fragment name]</i></code>"),
+
+  PROVIDER("Providers",
+      "<a href=\"/docs/skylark/rules.html#providers\">Providers</a> give rules access "
+      + " to information from their dependencies. "
+      + " <p>This section lists providers available on built-in rules. Rule implementation "
+      + " functions can access them via "
+      + "<code><a href=\"/docs/skylark/lib/ctx.html\">target</a>.<i>[provider name]</i></code>."
+  ),
+
+  BUILTIN("Built-in Types and Modules", ""),
+
+  TOP_LEVEL_TYPE,
+  NONE;
+
+  private final String title;
+  private final String description;
+
+
+  SkylarkModuleCategory(String title, String description) {
+    this.title = title;
+    this.description = description;
+  }
+
+  SkylarkModuleCategory() {
+    this.title = null;
+    this.description = null;
+  }
+
+  public String getTemplateIdentifier() {
+    return name().toLowerCase().replace("_", "-");
+  }
+
+  public String getTitle() {
+    return title;
+  }
+
+  public String getDescription() {
+    return description;
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ClassObject.java b/src/main/java/com/google/devtools/build/lib/syntax/ClassObject.java
index cb13c65a30..638936d9c3 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ClassObject.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ClassObject.java
@@ -22,6 +22,7 @@ import com.google.common.collect.Sets.SetView;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.util.Preconditions;
 
 import java.io.Serializable;
@@ -53,15 +54,17 @@ public interface ClassObject {
    */
   @Nullable String errorMessage(String name);
 
-  /**
-   * An implementation class of ClassObject for structs created in Skylark code.
-   */
+  /** An implementation class of ClassObject for structs created in Skylark code. */
   // TODO(bazel-team): maybe move the SkylarkModule annotation to the ClassObject interface?
   @Immutable
-  @SkylarkModule(name = "struct",
-      doc = "A special language element to support structs (i.e. simple value objects). "
-          + "See the global <a href=\"globals.html#struct\">struct</a> function "
-          + "for more details.")
+  @SkylarkModule(
+    name = "struct",
+    category = SkylarkModuleCategory.BUILTIN,
+    doc =
+        "A special language element to support structs (i.e. simple value objects). "
+            + "See the global <a href=\"globals.html#struct\">struct</a> function "
+            + "for more details."
+  )
   public class SkylarkClassObject implements ClassObject, Serializable {
     /** Error message to use when errorMessage argument is null. */
     private static final String DEFAULT_ERROR_MESSAGE = "'struct' object has no attribute '%s'";
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/MethodLibrary.java b/src/main/java/com/google/devtools/build/lib/syntax/MethodLibrary.java
index 37d489f892..ad525347ca 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/MethodLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/MethodLibrary.java
@@ -26,6 +26,7 @@ import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
@@ -2227,11 +2228,10 @@ public class MethodLibrary {
     }
   };
 
-  /**
-   * Skylark String module.
-   */
+  /** Skylark String module. */
   @SkylarkModule(
     name = "string",
+    category = SkylarkModuleCategory.BUILTIN,
     doc =
         "A language built-in type to support strings. "
             + "Examples of string literals:<br>"
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java
index 8cb1926bb5..254264ea49 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.SkylarkMutable.MutableMap;
 
 import java.util.Map;
@@ -26,8 +27,9 @@ import javax.annotation.Nullable;
 /**
  * Skylark Dict module.
  */
-@SkylarkModule(name = "dict", doc =
-    "A language built-in type to support dicts. "
+@SkylarkModule(name = "dict",
+    category = SkylarkModuleCategory.BUILTIN,
+    doc = "A language built-in type to support dicts. "
     + "Example of dict literal:<br>"
     + "<pre class=\"language-python\">d = {\"a\": 2, \"b\": 5}</pre>"
     + "Use brackets to access elements:<br>"
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkList.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkList.java
index 5855824bb1..890d16c46e 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkList.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkList.java
@@ -19,6 +19,7 @@ import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.SkylarkMutable.MutableCollection;
 
 import java.util.ArrayList;
@@ -30,13 +31,14 @@ import java.util.RandomAccess;
 
 import javax.annotation.Nullable;
 
-/**
- * A class to handle lists and tuples in Skylark.
- */
-@SkylarkModule(name = "sequence", documented = false,
-    doc = "common type of lists and tuples")
-  public abstract class SkylarkList<E>
-    extends MutableCollection<E> implements List<E>, RandomAccess {
+/** A class to handle lists and tuples in Skylark. */
+@SkylarkModule(
+  name = "sequence",
+  documented = false,
+  category = SkylarkModuleCategory.BUILTIN,
+  doc = "common type of lists and tuples"
+)
+public abstract class SkylarkList<E> extends MutableCollection<E> implements List<E>, RandomAccess {
 
   /**
    * Returns an ImmutableList object with the current underlying contents of this SkylarkList.
@@ -192,11 +194,10 @@ import javax.annotation.Nullable;
     return castList(getContentsUnsafe(), type, description);
   }
 
-  /**
-   * A class for mutable lists.
-   */
+  /** A class for mutable lists. */
   @SkylarkModule(
     name = "list",
+    category = SkylarkModuleCategory.BUILTIN,
     doc =
         "A language built-in type to support lists. Example of list literal:<br>"
             + "<pre class=language-python>x = [1, 2, 3]</pre>"
@@ -406,11 +407,10 @@ import javax.annotation.Nullable;
     public static final MutableList EMPTY = new MutableList(Tuple.EMPTY);
   }
 
-  /**
-   * An immutable tuple, e.g. in (1, 2, 3)
-   */
+  /** An immutable tuple, e.g. in (1, 2, 3) */
   @SkylarkModule(
     name = "tuple",
+    category = SkylarkModuleCategory.BUILTIN,
     doc =
         "A language built-in type to support tuples. Example of tuple literal:<br>"
             + "<pre class=language-python>x = (1, 2, 3)</pre>"
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkNestedSet.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkNestedSet.java
index 25ef2865e7..bd4be21685 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkNestedSet.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkNestedSet.java
@@ -21,6 +21,7 @@ import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.util.Preconditions;
 
@@ -32,50 +33,52 @@ import java.util.Set;
 
 import javax.annotation.Nullable;
 
-/**
- * A generic type safe NestedSet wrapper for Skylark.
- */
-@SkylarkModule(name = "set",
-    doc = "A language built-in type that supports sets. "
-        + "Sets can be created using the <a href=\"globals.html#set\">set</a> function, and "
-        + "they support the <code>|</code> operator to extend the set with more elements or "
-        + "to nest other sets inside of it. Examples:<br>"
-        + "<pre class=language-python>s = set([1, 2])\n"
-        + "s = s | [3]           # s == {1, 2, 3}\n"
-        + "s = s | set([4, 5])   # s == {1, 2, 3, {4, 5}}\n"
-        + "other = set([\"a\", \"b\", \"c\"], order=\"compile\")</pre>"
-        + "Note that in these examples <code>{..}</code> is not a valid literal to create sets. "
-        + "Sets have a fixed generic type, so <code>set([1]) + [\"a\"]</code> or "
-        + "<code>set([1]) + set([\"a\"])</code> results in an error.<br>"
-        + "Elements in a set can neither be mutable or be of type <code>list</code>, "
-        + "<code>struct</code> or <code>dict</code>.<br>"
-        + "When aggregating data from providers, sets can take significantly less memory than "
-        + "other types as they support nesting, that is, their subsets are shared in memory.<br>"
-        + "Every set has an <code>order</code> parameter which determines the iteration order. "
-        + "There are four possible values:"
-        + "<ul><li><code>compile</code>: Defines a left-to-right post-ordering where child "
-        + "elements come after those of nested sets (parent-last). For example, "
-        + "<code>{1, 2, 3, {4, 5}}</code> leads to <code>4 5 1 2 3</code>. Left-to-right order "
-        + "is preserved for both the child elements and the references to nested sets.</li>"
-        + "<li><code>stable</code>: Same behavior as <code>compile</code>.</li>"
-        + "<li><code>link</code>: Defines a variation of left-to-right pre-ordering, i.e. "
-        + "<code>{1, 2, 3, {4, 5}}</code> leads to <code>1 2 3 4 5</code>. "
-        + "This ordering enforces that elements of the set always come before elements of "
-        + "nested sets (parent-first), which may lead to situations where left-to-right "
-        + "order cannot be preserved (<a href=\"https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/collect/nestedset/LinkOrderExpander.java#L56\">Example</a>)."
-        + "</li>"
-        + "<li><code>naive_link</code>: Defines \"naive\" left-to-right pre-ordering "
-        + "(parent-first), i.e. <code>{1, 2, 3, {4, 5}}</code> leads to <code>1 2 3 4 5</code>. "
-        + "Unlike <code>link</code> ordering, it will sacrifice the parent-first property in "
-        + "order to uphold left-to-right order in cases where both properties cannot be "
-        + "guaranteed (<a href=\"https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/collect/nestedset/NaiveLinkOrderExpander.java#L26\">Example</a>)."
-        + "</li></ul>"
-        + "Except for <code>stable</code>, the above values are incompatible with each other. "
-        + "Consequently, two sets can only be merged via the <code>|</code> operator or via "
-        + "<code>union()</code> if either both sets have the same <code>order</code> or one of "
-        + "the sets has <code>stable</code> order. In the latter case the iteration order will be "
-        + "determined by the outer set, thus ignoring the <code>order</code> parameter of "
-        + "nested sets.")
+/** A generic type safe NestedSet wrapper for Skylark. */
+@SkylarkModule(
+  name = "set",
+  category = SkylarkModuleCategory.BUILTIN,
+  doc =
+      "A language built-in type that supports sets. "
+      + "Sets can be created using the <a href=\"globals.html#set\">set</a> function, and "
+      + "they support the <code>|</code> operator to extend the set with more elements or "
+      + "to nest other sets inside of it. Examples:<br>"
+      + "<pre class=language-python>s = set([1, 2])\n"
+      + "s = s | [3]           # s == {1, 2, 3}\n"
+      + "s = s | set([4, 5])   # s == {1, 2, 3, {4, 5}}\n"
+      + "other = set([\"a\", \"b\", \"c\"], order=\"compile\")</pre>"
+      + "Note that in these examples <code>{..}</code> is not a valid literal to create sets. "
+      + "Sets have a fixed generic type, so <code>set([1]) + [\"a\"]</code> or "
+      + "<code>set([1]) + set([\"a\"])</code> results in an error.<br>"
+      + "Elements in a set can neither be mutable or be of type <code>list</code>, "
+      + "<code>struct</code> or <code>dict</code>.<br>"
+      + "When aggregating data from providers, sets can take significantly less memory than "
+      + "other types as they support nesting, that is, their subsets are shared in memory.<br>"
+      + "Every set has an <code>order</code> parameter which determines the iteration order. "
+      + "There are four possible values:"
+      + "<ul><li><code>compile</code>: Defines a left-to-right post-ordering where child "
+      + "elements come after those of nested sets (parent-last). For example, "
+      + "<code>{1, 2, 3, {4, 5}}</code> leads to <code>4 5 1 2 3</code>. Left-to-right order "
+      + "is preserved for both the child elements and the references to nested sets.</li>"
+      + "<li><code>stable</code>: Same behavior as <code>compile</code>.</li>"
+      + "<li><code>link</code>: Defines a variation of left-to-right pre-ordering, i.e. "
+      + "<code>{1, 2, 3, {4, 5}}</code> leads to <code>1 2 3 4 5</code>. "
+      + "This ordering enforces that elements of the set always come before elements of "
+      + "nested sets (parent-first), which may lead to situations where left-to-right "
+      + "order cannot be preserved (<a href=\"https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/collect/nestedset/LinkOrderExpander.java#L56\">Example</a>)."
+      + "</li>"
+      + "<li><code>naive_link</code>: Defines \"naive\" left-to-right pre-ordering "
+      + "(parent-first), i.e. <code>{1, 2, 3, {4, 5}}</code> leads to <code>1 2 3 4 5</code>. "
+      + "Unlike <code>link</code> ordering, it will sacrifice the parent-first property in "
+      + "order to uphold left-to-right order in cases where both properties cannot be "
+      + "guaranteed (<a href=\"https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/collect/nestedset/NaiveLinkOrderExpander.java#L26\">Example</a>)."
+      + "</li></ul>"
+      + "Except for <code>stable</code>, the above values are incompatible with each other. "
+      + "Consequently, two sets can only be merged via the <code>|</code> operator or via "
+      + "<code>union()</code> if either both sets have the same <code>order</code> or one of "
+      + "the sets has <code>stable</code> order. In the latter case the iteration order will be "
+      + "determined by the outer set, thus ignoring the <code>order</code> parameter of "
+      + "nested sets."
+)
 @Immutable
 public final class SkylarkNestedSet implements Iterable<Object>, SkylarkValue {