diff --git a/src/main/java/com/google/devtools/build/docgen/ApiExporter.java b/src/main/java/com/google/devtools/build/docgen/ApiExporter.java
index c9743ba..427baf69 100644
--- a/src/main/java/com/google/devtools/build/docgen/ApiExporter.java
+++ b/src/main/java/com/google/devtools/build/docgen/ApiExporter.java
@@ -151,8 +151,7 @@
 
   private static Value.Builder valueFromMethodDescriptor(MethodDescriptor descriptor) {
     SkylarkSignatureProcessor.SignatureInfo info =
-        SkylarkSignatureProcessor.getSignatureForCallable(
-            descriptor.getName(), descriptor, null, null);
+        SkylarkSignatureProcessor.getSignatureForCallable(descriptor);
     return collectFunctionInfo(descriptor.getName(), info.signature, info.defaultValues);
   }
 
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 a876bec..8cad380 100644
--- a/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
+++ b/src/main/java/com/google/devtools/build/docgen/SkylarkDocumentationCollector.java
@@ -15,7 +15,6 @@
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
-import com.google.devtools.build.docgen.skylark.SkylarkBuiltinMethodDoc;
 import com.google.devtools.build.docgen.skylark.SkylarkConstructorMethodDoc;
 import com.google.devtools.build.docgen.skylark.SkylarkJavaMethodDoc;
 import com.google.devtools.build.docgen.skylark.SkylarkModuleDoc;
@@ -24,10 +23,8 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkGlobalLibrary;
 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.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.syntax.CallUtils;
-import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Map;
 import java.util.TreeMap;
@@ -80,8 +77,6 @@
       if (candidateClass.isAnnotationPresent(SkylarkGlobalLibrary.class)) {
         collectGlobalLibraryMethods(candidateClass, modules);
       }
-      // Use of SkylarkSignature fields is deprecated, but not all uses have been migrated.
-      collectSkylarkSignatureFunctions(candidateClass, modules);
     }
 
     // 3. Add all constructors.
@@ -218,31 +213,6 @@
     }
   }
 
-  /**
-   * Adds {@link SkylarkBuiltinMethodDoc} entries to the top level module, one for
-   * each @SkylarkSignature-annotated field defined in the given {@code moduleClass}.
-   *
-   * <p>Note that use of SkylarkSignature fields is deprecated, but not all uses have been migrated.
-   */
-  private static void collectSkylarkSignatureFunctions(
-      Class<?> moduleClass, Map<String, SkylarkModuleDoc> modules) {
-
-    SkylarkModuleDoc topLevelModuleDoc = getTopLevelModuleDoc(modules);
-
-    // Collect any fields annotated with @SkylarkSignature, even if the class isn't
-    // annotated.
-    for (Field field : moduleClass.getDeclaredFields()) {
-      if (field.isAnnotationPresent(SkylarkSignature.class)) {
-        SkylarkSignature skylarkSignature = field.getAnnotation(SkylarkSignature.class);
-        Preconditions.checkState(skylarkSignature.objectType() == Object.class);
-
-        topLevelModuleDoc.addMethod(
-            new SkylarkBuiltinMethodDoc(
-                getTopLevelModuleDoc(modules), skylarkSignature, field.getType()));
-      }
-    }
-  }
-
   private static void collectConstructor(
       Map<String, SkylarkModuleDoc> modules,
       Class<?> moduleClass,
diff --git a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkBuiltinMethodDoc.java b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkBuiltinMethodDoc.java
deleted file mode 100644
index 5c0ba8e..0000000
--- a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkBuiltinMethodDoc.java
+++ /dev/null
@@ -1,98 +0,0 @@
-// Copyright 2014 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.docgen.skylark;
-
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
-import com.google.devtools.build.lib.syntax.BaseFunction;
-import com.google.devtools.build.lib.syntax.EvalUtils;
-import java.util.List;
-
-/** A class representing a Skylark built-in object or method. */
-@Deprecated
-public final class SkylarkBuiltinMethodDoc extends SkylarkMethodDoc {
-  private final SkylarkModuleDoc module;
-  private final SkylarkSignature annotation;
-  private final Class<?> fieldClass;
-  private List<SkylarkParamDoc> params;
-
-  public SkylarkBuiltinMethodDoc(SkylarkModuleDoc module, SkylarkSignature annotation,
-      Class<?> fieldClass) {
-    this.module = module;
-    this.annotation = annotation;
-    this.fieldClass = fieldClass;
-    this.params =
-        SkylarkDocUtils.determineParams(
-            this,
-            withoutSelfParam(annotation),
-            annotation.extraPositionals(),
-            annotation.extraKeywords());
-  }
-
-  @Override
-  public boolean isDeprecated() {
-    return false;
-  }
-
-  public SkylarkSignature getAnnotation() {
-    return annotation;
-  }
-
-  @Override
-  public boolean documented() {
-    return annotation.documented();
-  }
-
-  @Override
-  public String getName() {
-    return annotation.name();
-  }
-
-  @Override
-  public String getDocumentation() {
-    return SkylarkDocUtils.substituteVariables(annotation.doc());
-  }
-
-  /**
-   * Returns a string representing the method signature with links to the types if
-   * available.
-   *
-   * <p>If the built-in method is a function, the construct the method signature. Otherwise,
-   * return a string containing the return type of the method.
-   */
-  @Override
-  public String getSignature() {
-    if (BaseFunction.class.isAssignableFrom(fieldClass)) {
-      return getSignature(module.getName(), annotation);
-    }
-    if (!annotation.returnType().equals(Object.class)) {
-      return getTypeAnchor(annotation.returnType());
-    }
-    return "";
-  }
-
-  @Override
-  public String getReturnType() {
-    return EvalUtils.getDataTypeNameFromClass(annotation.returnType());
-  }
-
-  @Override
-  public Boolean isCallable() {
-    return BaseFunction.class.isAssignableFrom(fieldClass);
-  }
-
-  @Override
-  public List<SkylarkParamDoc> getParams() {
-    return params;
-  }
-}
diff --git a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkDoc.java b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkDoc.java
index 12072d2..d2f8d39 100644
--- a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkDoc.java
+++ b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkDoc.java
@@ -19,8 +19,6 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkInterfaceUtils;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
-import com.google.devtools.build.lib.syntax.CallUtils;
 import com.google.devtools.build.lib.syntax.EvalUtils;
 import com.google.devtools.build.lib.syntax.Runtime.NoneType;
 import com.google.devtools.build.lib.syntax.SkylarkList;
@@ -83,22 +81,6 @@
   }
 
   // Omit self parameter from parameters in class methods.
-  protected static Param[] withoutSelfParam(SkylarkSignature annotation) {
-    Param[] params = annotation.parameters();
-    if (params.length > 0
-        && !params[0].named()
-        && (params[0].defaultValue() != null && params[0].defaultValue().isEmpty())
-        && params[0].positional()
-        && annotation.objectType() != Object.class
-        && !CallUtils.isNamespace(annotation.objectType())) {
-      // Skip the self parameter, which is the first mandatory positional parameter.
-      return Arrays.copyOfRange(params, 1, params.length);
-    } else {
-      return params;
-    }
-  }
-
-  // Omit self parameter from parameters in class methods.
   protected static Param[] withoutSelfParam(SkylarkCallable annotation, Method method) {
     Param[] params = annotation.parameters();
     if (params.length > 0) {
diff --git a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkMethodDoc.java b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkMethodDoc.java
index d7c2057..d40d643 100644
--- a/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkMethodDoc.java
+++ b/src/main/java/com/google/devtools/build/docgen/skylark/SkylarkMethodDoc.java
@@ -18,7 +18,6 @@
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkInterfaceUtils;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
@@ -115,37 +114,6 @@
         getTypeAnchor(method.getReturnType()), fullyQualifiedMethodName, args);
   }
 
-  protected String getSignature(String objectName, SkylarkSignature method) {
-    List<String> argList = new ArrayList<>();
-    boolean named = false;
-    for (Param param : withoutSelfParam(method)) {
-      if (param.named() && !param.positional() && !named) {
-        named = true;
-        if (!method.extraPositionals().name().isEmpty()) {
-          argList.add("*" + method.extraPositionals().name());
-        }
-        if (!argList.isEmpty()) {
-          argList.add("*");
-        }
-      }
-      argList.add(formatParameter(param));
-    }
-    if (!named && !method.extraPositionals().name().isEmpty()) {
-      argList.add("*" + method.extraPositionals().name());
-    }
-    if (!method.extraKeywords().name().isEmpty()) {
-      argList.add("**" + method.extraKeywords().name());
-    }
-    String args = "(" + Joiner.on(", ").join(argList) + ")";
-    if (!objectName.equals(TOP_LEVEL_ID)) {
-      return String.format("%s %s.%s%s\n",
-          getTypeAnchor(method.returnType()), objectName, method.name(), args);
-    } else {
-      return String.format("%s %s%s\n",
-          getTypeAnchor(method.returnType()), method.name(), args);
-    }
-  }
-
   private String formatParameter(Param param) {
     String defaultValue = param.defaultValue();
     String name = param.name();
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 999f583..4a59a17 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
@@ -20,24 +20,20 @@
 import com.google.common.collect.Multimap;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.skylarkinterface.StarlarkDeprecated;
 import java.text.Collator;
 import java.util.Collection;
 import java.util.Locale;
-import java.util.Map;
 import java.util.TreeMap;
 import javax.annotation.Nullable;
 
 /**
  * A class representing documentation for a Skylark built-in object with its {@link SkylarkModule}
- * annotation and with the {@link SkylarkCallable} methods and {@link SkylarkSignature} fields it
- * documents.
+ * annotation and with the {@link SkylarkCallable} methods it documents.
  */
 public final class SkylarkModuleDoc extends SkylarkDoc {
   private final SkylarkModule module;
   private final Class<?> classObject;
-  private final Map<String, SkylarkBuiltinMethodDoc> builtinMethodMap;
   private final Multimap<String, SkylarkJavaMethodDoc> javaMethods;
   private TreeMap<String, SkylarkMethodDoc> methodMap;
   private final String title;
@@ -48,7 +44,6 @@
     this.module = Preconditions.checkNotNull(
         module, "Class has to be annotated with SkylarkModule: %s", classObject);
     this.classObject = classObject;
-    this.builtinMethodMap = new TreeMap<>(Collator.getInstance(Locale.US));
     this.methodMap = new TreeMap<>(Collator.getInstance(Locale.US));
     this.javaMethods = HashMultimap.<String, SkylarkJavaMethodDoc>create();
     this.deprecated = classObject.isAnnotationPresent(StarlarkDeprecated.class);
@@ -91,11 +86,6 @@
     javaConstructor = method;
   }
 
-  public void addMethod(SkylarkBuiltinMethodDoc method) {
-    methodMap.put(method.getName(), method);
-    builtinMethodMap.put(method.getName(), method);
-  }
-
   public void addMethod(SkylarkJavaMethodDoc method) {
     if (!method.documented()) {
       return;
@@ -126,10 +116,6 @@
     return javaMethods.isEmpty();
   }
 
-  public Map<String, SkylarkBuiltinMethodDoc> getBuiltinMethods() {
-    return builtinMethodMap;
-  }
-
   public Collection<SkylarkMethodDoc> getJavaMethods() {
     ImmutableList.Builder<SkylarkMethodDoc> returnedMethods = ImmutableList.builder();
     if (javaConstructor != null) {
diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java b/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
index cc83cea..6d65a73 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
@@ -57,7 +57,6 @@
 import com.google.devtools.build.lib.syntax.NodeVisitor;
 import com.google.devtools.build.lib.syntax.ParserInput;
 import com.google.devtools.build.lib.syntax.Runtime;
-import com.google.devtools.build.lib.syntax.SkylarkSignatureProcessor;
 import com.google.devtools.build.lib.syntax.SkylarkUtils;
 import com.google.devtools.build.lib.syntax.SkylarkUtils.Phase;
 import com.google.devtools.build.lib.syntax.Starlark;
@@ -141,10 +140,8 @@
     /** Update the predeclared environment of WORKSPACE files. */
     void updateWorkspace(ImmutableMap.Builder<String, Object> env);
 
-    /**
-     * Returns the extra functions needed to be added to the Skylark native module.
-     */
-    ImmutableList<BaseFunction> nativeModuleFunctions();
+    /** Update the environment of the native module. */
+    void updateNative(ImmutableMap.Builder<String, Object> env);
 
     /**
      * Returns the extra arguments to the {@code package()} statement.
@@ -904,10 +901,8 @@
     builder.putAll(SkylarkNativeModule.BINDINGS_FOR_BUILD_FILES);
     builder.putAll(ruleFunctions);
     builder.put("package", newPackageFunction(packageArguments));
-    for (EnvironmentExtension extension : environmentExtensions) {
-      for (BaseFunction function : extension.nativeModuleFunctions()) {
-        builder.put(function.getName(), function);
-      }
+    for (EnvironmentExtension ext : environmentExtensions) {
+      ext.updateNative(builder);
     }
     return StructProvider.STRUCT.create(builder.build(), "no native function or rule '%s'");
   }
@@ -1148,10 +1143,6 @@
     return true;
   }
 
-  static {
-    SkylarkSignatureProcessor.configureSkylarkFunctions(PackageFactory.class);
-  }
-
   /**
    * checkBuildSyntax checks the syntax tree of a BUILD (not .bzl) file. If it discovers a 'def',
    * 'if', or 'for' statement, or a f(*args) or f(**kwargs) call, it reports an event to handler and
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index 1302309..2bbfd58 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -1319,10 +1319,6 @@
     CustomExitCodePublisher.setAbruptExitStatusFileDir(
         serverDirectories.getOutputBase().getPathString());
 
-    // Most static initializers for @SkylarkSignature-containing classes have already run by this
-    // point, but this will pick up the stragglers.
-    initSkylarkBuiltinsRegistry();
-
     AutoProfiler.setClock(runtime.getClock());
     BugReport.setRuntime(runtime);
     BlazeDirectories directories =
@@ -1341,38 +1337,6 @@
     return runtime;
   }
 
-  /**
-   * Configures the Skylark builtins registry.
-   *
-   * <p>Any class containing {@link SkylarkSignature}-annotated fields should call
-   * {@link SkylarkSignatureProcessor#configureSkylarkFunctions} on itself. This serves two
-   * purposes: 1) it initializes those fields for use, and 2) it registers them with the Skylark
-   * builtins registry object
-   * ({@link com.google.devtools.build.lib.syntax.Runtime#getBuiltinRegistry}). Unfortunately
-   * there's some technical debt here: The registry object is static and the registration occurs
-   * inside static initializer blocks.
-   *
-   * <p>The registry supports concurrent read/write access, but read access is not actually
-   * efficient (lockless) until write access is disallowed by calling its
-   * {@link com.google.devtools.build.lib.syntax.Runtime.BuiltinRegistry#freeze freeze} method.
-   * We want to freeze before the build begins, but not before all classes have had a chance to run
-   * their static initializers.
-   *
-   * <p>Therefore, this method first ensures that the initializers have run, and then explicitly
-   * freezes the registry. It ensures initialization by calling a no-op static method on the class.
-   * Only classes whose initializers have been observed to cause {@code BuiltinRegistry} to throw an
-   * exception need to be included here, since that indicates that their initialization did not
-   * happen by this point in time.
-   *
-   * <p>Unit tests don't need to worry about registry freeze exceptions, since the registry isn't
-   * frozen at all for them. They just pay the cost of extra synchronization on every access.
-   */
-  private static void initSkylarkBuiltinsRegistry() {
-    // Currently no classes need to be initialized here. The hook's still here because it's
-    // possible it may be needed again in the future.
-    com.google.devtools.build.lib.syntax.Runtime.getBuiltinRegistry().freeze();
-  }
-
   private static String maybeGetPidString() {
     Integer pid = maybeForceJNIByGettingPid(null);
     return pid == null ? "" : "pid " + pid + " and ";
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkinterface/Param.java b/src/main/java/com/google/devtools/build/lib/skylarkinterface/Param.java
index f44bcbf..c56be4b 100644
--- a/src/main/java/com/google/devtools/build/lib/skylarkinterface/Param.java
+++ b/src/main/java/com/google/devtools/build/lib/skylarkinterface/Param.java
@@ -106,11 +106,11 @@
   /**
    * If this true, {@link #named} should be treated as true.
    *
-   * <p>This indicates this parameter is part of a {@link SkylarkCallable} method which
-   * was migrated from {@link SkylarkSignature}. Due to a pre-migration bug, all parameters were
-   * treated as if {@link #named} was true, even if it was false. To prevent breakages during
-   * migration, the interpreter can continue to treat these parameters as named. This is distinct
-   * from {@link #named}, however, so that a bulk fix/cleanup will be easier later.
+   * <p>This indicates this parameter is part of a {@link SkylarkCallable} method which was migrated
+   * from {@code SkylarkSignature}. Due to a pre-migration bug, all parameters were treated as if
+   * {@link #named} was true, even if it was false. To prevent breakages during migration, the
+   * interpreter can continue to treat these parameters as named. This is distinct from {@link
+   * #named}, however, so that a bulk fix/cleanup will be easier later.
    */
   // TODO(b/77902276): Remove this after a bulk cleanup/fix.
   boolean legacyNamed() default false;
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkSignature.java b/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkSignature.java
deleted file mode 100644
index 5942b68..0000000
--- a/src/main/java/com/google/devtools/build/lib/skylarkinterface/SkylarkSignature.java
+++ /dev/null
@@ -1,120 +0,0 @@
-// Copyright 2014 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;
-
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-/**
- * An annotation to mark built-in keyword argument methods accessible from Skylark.
- *
- * <p>Use this annotation around a {@link com.google.devtools.build.lib.syntax.BuiltinFunction}. The
- * annotated function should expect the arguments described by {@link #parameters()}, {@link
- * #extraPositionals()}, and {@link #extraKeywords()}. It should also expect the following
- * extraneous arguments:
- *
- * <ul>
- *   <li>{@link com.google.devtools.build.lib.events.Location} if {@link #useLocation()} is true.
- *   <li>{@link com.google.devtools.build.lib.syntax.Node} if {@link #useAst()} is true.
- *   <li>{@link com.google.devtools.build.lib.syntax.StarlarkThread} if {@link #useStarlarkThread()}
- *       )} is true.
- * </ul>
- */
-@Target({ElementType.FIELD})
-@Retention(RetentionPolicy.RUNTIME)
-public @interface SkylarkSignature {
-
-  // TODO(bazel-team): parse most everything from single string specifying the signature
-  // in Skylark syntax, e.g.: signature = "foo(a: string, b: ListOf(int)) -> NoneType"
-  // String signature() default "";
-
-  /**
-   * Name of the method as exposed to Skylark.
-   */
-  String name();
-
-  /**
-   * General documentation block of the method. See the skylark documentation at
-   * http://www.bazel.build/docs/skylark/.
-   */
-  String doc() default "";
-
-  /**
-   * List of parameters for calling this method. Named only parameters are expected to be last.
-   */
-  Param[] parameters() default {};
-
-  /**
-   * Defines a catch all positional parameters. By default, it is an error to define more
-   * positional parameters that specified but by defining an extraPositionals argument, one can
-   * catch those. See python's <code>*args</code>
-   * (http://thepythonguru.com/python-args-and-kwargs/).
-   */
-  Param extraPositionals() default @Param(name = "");
-
-  /**
-   * Defines a catch all named parameters. By default, it is an error to define more
-   * named parameters that specified but by defining an extraKeywords argument, one can catch those.
-   * See python's <code>**kwargs</code> (http://thepythonguru.com/python-args-and-kwargs/).
-   */
-  Param extraKeywords() default @Param(name = "");
-
-  /**
-   * Set <code>documented</code> to <code>false</code> if this method should not be mentioned
-   * in the documentation of Skylark. This is generally used for experimental APIs or duplicate
-   * methods already documented on another call.
-   */
-  boolean documented() default true;
-
-  /**
-   * Type of the object associated to that function. If this field is
-   * <code>Object.class</code>, then the function will be considered as an object method.
-   * For example, to add a function to the string object, set it to <code>String.class</code>.
-   */
-  Class<?> objectType() default Object.class;
-
-  /**
-   * Return type of the function. Use {@link com.google.devtools.build.lib.syntax.Runtime.NoneType}
-   * for a void function.
-   */
-  Class<?> returnType() default Object.class;
-
-  /**
-   * Fake return type of the function. Used by the documentation generator for documenting
-   * deprecated functions (documentation for this type is generated, even if it's not the real
-   * return type).
-   */
-  Class<?> documentationReturnType() default Object.class;
-
-  // TODO(bazel-team): determine this way whether to accept mutable Lists
-  // boolean mutableLists() default false;
-
-  /**
-   * If true the location of the call site will be passed as an argument of the annotated function.
-   */
-  boolean useLocation() default false;
-
-  /**
-   * If true the AST of the call site will be passed as an argument of the annotated function.
-   */
-  boolean useAst() default false;
-
-  /**
-   * If true the ({@link com.google.devtools.build.lib.syntax.StarlarkThread}) will be passed as an
-   * argument of the annotated function.
-   */
-  boolean useStarlarkThread() default false;
-}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java b/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java
index 9b6db90..fb42720 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java
@@ -488,7 +488,8 @@
     // implementation, so this statement does not clobber the
     // enforcedArgumentTypes computed by getSignatureForCallable.
     // Still it is hard to explain what the configure method does.
-    // TODO(adonovan): eliminate SkylarkSignature then simplify.
+
+    // TODO(adonovan): simplify now that SkylarkSignature is gone.
     this.enforcedArgumentTypes = this.paramTypes;
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java b/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
index 39de391..74c91e4 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
@@ -21,12 +21,10 @@
 import com.google.devtools.build.lib.profiler.ProfilerTask;
 import com.google.devtools.build.lib.profiler.SilentCloseable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.SkylarkType.SkylarkFunctionType;
 import com.google.devtools.build.lib.syntax.StarlarkThread.LexicalFrame;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.NoSuchElementException;
@@ -169,28 +167,6 @@
   }
 
   /**
-   * Configure the reflection mechanism. Called by signature processor for BuiltinFunctions already
-   * created.
-   */
-  final void configureFromAnnotation(SkylarkSignature annotation) {
-    Preconditions.checkState(!isConfigured()); // must not be configured yet
-    this.enforcedArgumentTypes = new ArrayList<>();
-
-    this.returnType = annotation.returnType();
-
-    // Appends to getEnforcedArgumentTypes() and paramDoc as a side effect.
-    SkylarkSignatureProcessor.SignatureInfo info =
-        SkylarkSignatureProcessor.getSignatureForCallable(
-            getName(), annotation, /*paramDoc=*/ new ArrayList<>(), this.enforcedArgumentTypes);
-    this.signature = info.signature;
-    this.paramTypes = info.types;
-    this.defaultValues = info.defaultValues;
-
-    this.objectType = annotation.objectType() == Object.class ? null : annotation.objectType();
-    configure();
-  }
-
-  /**
    * Configure the reflection mechanism. Called directly by constructor for BuiltinFunctions created
    * with a signature, and called after annotation processing for other BuiltinFunctions.
    */
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/CallUtils.java b/src/main/java/com/google/devtools/build/lib/syntax/CallUtils.java
index c29a393..056231d 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/CallUtils.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/CallUtils.java
@@ -234,7 +234,8 @@
 
   /**
    * Returns a {@link BuiltinCallable} representing a {@link SkylarkCallable}-annotated instance
-   * method of a given object with the given Java method name.
+   * method of a given object with the given Starlark field name (not necessarily the same as the
+   * Java method name).
    */
   // TODO(adonovan): replace with EvalUtils.getAttr, once the latter doesn't require
   // a Thread and Location.
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FunctionSignature.java b/src/main/java/com/google/devtools/build/lib/syntax/FunctionSignature.java
index 705ad35..c00a452 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FunctionSignature.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FunctionSignature.java
@@ -410,7 +410,7 @@
     return of(0, 0, numMandatory, false, false, names);
   }
 
-  /** Invalid signature from Parser or from SkylarkSignature annotations */
+  /** Invalid signature from Parser or from SkylarkCallable annotation. */
   static class SignatureException extends Exception {
     private final Parameter parameter;
 
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java b/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java
index b17969b..7ef24e9 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java
@@ -23,7 +23,6 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkInterfaceUtils;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import java.util.HashMap;
 import java.util.Map;
@@ -36,14 +35,6 @@
 
   private Runtime() {}
 
-  // (for documentation only)
-  @SkylarkSignature(name = "True", returnType = Boolean.class, doc = "The Boolean true value.")
-  private static final Boolean TRUE = true;
-
-  // (for documentation only)
-  @SkylarkSignature(name = "False", returnType = Boolean.class, doc = "The Boolean false value.")
-  private static final Boolean FALSE = false;
-
   /** There should be only one instance of this type to allow "== None" tests. */
   @SkylarkModule(
     name = "NoneType",
@@ -75,6 +66,9 @@
     }
   }
 
+  /* The Starlark None value. */
+  public static final NoneType NONE = new NoneType();
+
   /** Marker for unbound variables in cases where neither Java null nor Skylark None is suitable. */
   @Immutable
   public static final class UnboundMarker implements SkylarkValue {
@@ -96,54 +90,8 @@
     }
   }
 
-  @SkylarkSignature(
-      name = "<unbound>",
-      returnType = UnboundMarker.class,
-      documented = false,
-      doc = "Marker for unbound values in cases where neither Starlark None nor Java null can do.")
   public static final UnboundMarker UNBOUND = new UnboundMarker();
 
-  @SkylarkSignature(name = "None", returnType = NoneType.class,
-      doc = "Literal for the None value.")
-  public static final NoneType NONE = new NoneType();
-
-  // (for documentation only)
-  @SkylarkSignature(
-      name = "PACKAGE_NAME",
-      returnType = String.class,
-      doc =
-          "<b>Deprecated. Use <a href=\"native.html#package_name\">package_name()</a> instead.</b>"
-              + " The name of the package being evaluated. For example, in the BUILD file"
-              + " <code>some/package/BUILD</code>, its value will be <code>some/package</code>. If"
-              + " the BUILD file calls a function defined in a .bzl file, PACKAGE_NAME will match"
-              + " the caller BUILD file package. In .bzl files, do not access PACKAGE_NAME at the"
-              + " file-level (outside of functions), either directly or by calling a function at"
-              + " the file-level that accesses PACKAGE_NAME (PACKAGE_NAME is only defined during"
-              + " BUILD file evaluation).Here is an example of a .bzl file:<br><pre"
-              + " class=language-python># a = PACKAGE_NAME  # not allowed outside functions\n"
-              + "def extension():\n"
-              + "  return PACKAGE_NAME</pre>In this case, <code>extension()</code> can be called"
-              + " from a BUILD file (even indirectly), but not in a file-level expression in the"
-              + " .bzl file. When implementing a rule, use <a"
-              + " href=\"ctx.html#label\">ctx.label</a> to know where the rule comes from. ")
-  private final String unusedPackageName = "PACKAGE_NAME";
-
-  // (for documentation only)
-  @SkylarkSignature(
-      name = "REPOSITORY_NAME",
-      returnType = String.class,
-      doc =
-          "<b>Deprecated. Use <a href=\"native.html#repository_name\">repository_name()</a> "
-              + "instead.</b> The name of the repository the rule or build extension is called "
-              + "from. "
-              + "For example, in packages that are called into existence by the WORKSPACE stanza "
-              + "<code>local_repository(name='local', path=...)</code> it will be set to "
-              + "<code>@local</code>. In packages in the main repository, it will be set to "
-              + "<code>@</code>. It can only be accessed in functions (transitively) called from "
-              + "BUILD files, i.e. it follows the same restrictions as "
-              + "<a href=\"#PACKAGE_NAME\">PACKAGE_NAME</a>.")
-  private final String unusedRepositoryName = "REPOSITORY_NAME";
-
   /**
    * Returns the canonical class representing the namespace associated with the given class, i.e.,
    * the class under which builtins should be registered.
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSignatureProcessor.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSignatureProcessor.java
index a974b32..d484339 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSignatureProcessor.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSignatureProcessor.java
@@ -17,8 +17,6 @@
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
-import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -27,8 +25,7 @@
 import javax.annotation.Nullable;
 
 /**
- * This class defines utilities to process @SkylarkSignature annotations
- * to configure a given field.
+ * This class defines utilities to process @SkylarkCallable annotations to configure a given field.
  */
 public class SkylarkSignatureProcessor {
 
@@ -55,71 +52,24 @@
     }
   }
 
-  /**
-   * Extracts signature information from a {@link SkylarkCallable}-annotated method.
-   *
-   * @param name the name of the function
-   * @param descriptor the method descriptor
-   * @param paramDoc an optional list into which to store documentation strings
-   * @param enforcedTypesList an optional list into which to store effective types to enforce
-   */
-  public static SignatureInfo getSignatureForCallable(
-      String name,
-      MethodDescriptor descriptor,
-      @Nullable List<String> paramDoc,
-      @Nullable List<SkylarkType> enforcedTypesList) {
-
+  /** Extracts signature information from a {@link SkylarkCallable}-annotated method descriptor. */
+  public static SignatureInfo getSignatureForCallable(MethodDescriptor descriptor) {
     SkylarkCallable annotation = descriptor.getAnnotation();
 
-    // TODO(cparsons): Validate these properties with the annotation processor instead.
-    Preconditions.checkArgument(name.equals(annotation.name()),
-        "%s != %s", name, annotation.name());
     boolean documented = annotation.documented();
     if (annotation.doc().isEmpty() && documented) {
-      throw new RuntimeException(String.format("function %s is undocumented", name));
+      throw new IllegalStateException(
+          String.format("function %s is undocumented", annotation.name()));
     }
 
     return getSignatureForCallableImpl(
-        name,
+        annotation.name(),
         documented,
         annotation.parameters(),
         annotation.extraPositionals(),
         annotation.extraKeywords(),
-        paramDoc,
-        enforcedTypesList);
-  }
-
-  /**
-   * Extracts signature information from a {@link SkylarkSignature} annotation.
-   *
-   * @param name the name of the function
-   * @param annotation the annotation
-   * @param paramDoc an optional list into which to store documentation strings
-   * @param enforcedTypesList an optional list into which to store effective types to enforce
-   */
-  // NB: the two arguments paramDoc and enforcedTypesList are used to "return" extra values via
-  // side-effects, and that's ugly
-  // TODO(bazel-team): use AutoValue to declare a value type to use as return value?
-  static SignatureInfo getSignatureForCallable(
-      String name,
-      SkylarkSignature annotation,
-      @Nullable List<String> paramDoc,
-      @Nullable List<SkylarkType> enforcedTypesList) {
-
-    Preconditions.checkArgument(name.equals(annotation.name()),
-        "%s != %s", name, annotation.name());
-    boolean documented = annotation.documented();
-    if (annotation.doc().isEmpty() && documented) {
-      throw new RuntimeException(String.format("function %s is undocumented", name));
-    }
-    return getSignatureForCallableImpl(
-        name,
-        documented,
-        annotation.parameters(),
-        annotation.extraPositionals(),
-        annotation.extraKeywords(),
-        paramDoc,
-        enforcedTypesList);
+        /*paramDoc=*/ null,
+        /*enforcedTypesList=*/ null);
   }
 
   private static boolean isParamNamed(Param param) {
@@ -336,60 +286,11 @@
       } catch (Exception e) {
         throw new RuntimeException(
             String.format(
-                "Exception while processing @SkylarkSignature.Param %s, default value %s",
+                "Exception while processing @Param %s, default value %s",
                 paramName, paramDefaultValue),
             e);
       }
     }
   }
 
-  /**
-   * Processes all {@link SkylarkSignature}-annotated fields in a class.
-   *
-   * <p>This includes registering these fields as builtins using {@link Runtime}, and for {@link
-   * BuiltinFunction} instances, calling {@link BuiltinFunction#configure(SkylarkSignature)}. The
-   * fields will be picked up by reflection even if they are not public.
-   *
-   * <p>This function should be called once per class, before the builtins registry is frozen. In
-   * practice, this is usually called from the class's own static initializer block. E.g., a class
-   * {@code Foo} containing {@code @SkylarkSignature} annotations would end with {@code static {
-   * SkylarkSignatureProcessor.configureSkylarkFunctions(Foo.class); }}.
-   *
-   * <p><b>If you see exceptions from {@link Runtime.BuiltinRegistry} here:</b> Be sure the class's
-   * static initializer has in fact been called before the registry was frozen. In Bazel, see {@link
-   * com.google.devtools.build.lib.runtime.BlazeRuntime#initSkylarkBuiltinsRegistry}.
-   */
-  public static void configureSkylarkFunctions(Class<?> type) {
-    Runtime.BuiltinRegistry builtins = Runtime.getBuiltinRegistry();
-    for (Field field : type.getDeclaredFields()) {
-      if (field.isAnnotationPresent(SkylarkSignature.class)) {
-        // The annotated fields are often private, but we need access them.
-        field.setAccessible(true);
-        SkylarkSignature annotation = field.getAnnotation(SkylarkSignature.class);
-        Object value = null;
-        try {
-          value =
-              Preconditions.checkNotNull(
-                  field.get(null),
-                  "Error while trying to configure %s.%s: its value is null",
-                  type,
-                  field);
-          builtins.registerBuiltin(type, field.getName(), value);
-          if (BuiltinFunction.class.isAssignableFrom(field.getType())) {
-            BuiltinFunction function = (BuiltinFunction) value;
-            if (!function.isConfigured()) {
-              function.configureFromAnnotation(annotation);
-            }
-            Class<?> nameSpace = function.getObjectType();
-            if (nameSpace != null) {
-              builtins.registerFunction(nameSpace, function);
-            }
-          }
-        } catch (IllegalAccessException e) {
-          throw new RuntimeException(String.format(
-              "Error while trying to configure %s.%s (value %s)", type, field, value), e);
-        }
-      }
-    }
-  }
 }
diff --git a/src/test/java/com/google/devtools/build/docgen/SkylarkDocumentationTest.java b/src/test/java/com/google/devtools/build/docgen/SkylarkDocumentationTest.java
index 2d89c1a..b789291 100644
--- a/src/test/java/com/google/devtools/build/docgen/SkylarkDocumentationTest.java
+++ b/src/test/java/com/google/devtools/build/docgen/SkylarkDocumentationTest.java
@@ -83,6 +83,14 @@
         undocumentedItems.add(varname);
       }
     }
+
+    // These constants are currently undocumented.
+    // If they need documentation, the easiest approach would be
+    // to hard-code it in SkylarkDocumentationCollector.
+    undocumentedItems.remove("True");
+    undocumentedItems.remove("False");
+    undocumentedItems.remove("None");
+
     assertWithMessage("Undocumented items: " + undocumentedItems)
         .that(undocumentedItems)
         .containsExactlyElementsIn(DEPRECATED_UNDOCUMENTED_TOP_LEVEL_SYMBOLS);
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/RuntimeTest.java b/src/test/java/com/google/devtools/build/lib/syntax/RuntimeTest.java
index 06e68ba..6f1fb52 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/RuntimeTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/RuntimeTest.java
@@ -28,14 +28,15 @@
 @RunWith(JUnit4.class)
 public final class RuntimeTest {
 
-  private static final BuiltinFunction DUMMY_FUNC = new BuiltinFunction("dummyFunc") {
-    // This would normally be done by @SkylarkSignature annotation and configure(), but a simple
-    // stub suffices.
-    @Override
-    public Class<?> getObjectType() {
-      return DummyType.class;
-    }
-  };
+  private static final BuiltinFunction DUMMY_FUNC =
+      new BuiltinFunction("dummyFunc") {
+        // This would normally be done by @SkylarkCallable annotation and configure(), but a simple
+        // stub suffices.
+        @Override
+        public Class<?> getObjectType() {
+          return DummyType.class;
+        }
+      };
 
   private static class DummyType implements SkylarkValue {
     @Override
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
index a7da512..ec4a25e 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
@@ -32,8 +32,8 @@
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.ParamType;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkGlobalLibrary;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
 import com.google.devtools.build.lib.syntax.StarlarkSemantics.FlagIdentifier;
@@ -48,6 +48,7 @@
 /** Tests of Starlark evaluation. */
 // This test uses 'extends' to make a copy of EvaluationTest whose
 // mode is overridden to SKYLARK, changing various environmental parameters.
+@SkylarkGlobalLibrary // required for @SkylarkCallable-annotated methods
 @RunWith(JUnit4.class)
 public final class SkylarkEvaluationTest extends EvaluationTest {
 
@@ -71,29 +72,21 @@
     }
   }
 
-  @SkylarkSignature(name = "foobar", returnType = String.class, documented = false)
-  static BuiltinFunction foobar = new BuiltinFunction("foobar") {
-    public String invoke() throws EvalException {
-      return "foobar";
-    }
-  };
+  @SkylarkCallable(name = "foobar", documented = false)
+  public String foobar() {
+    return "foobar";
+  }
 
-  @SkylarkSignature(
-      name = "interrupted_function",
-      returnType = Runtime.NoneType.class,
-      documented = false)
-  static BuiltinFunction interruptedFunction =
-      new BuiltinFunction("interrupted_function") {
-        public Runtime.NoneType invoke() throws InterruptedException {
-          throw new InterruptedException();
-        }
-      };
+  @SkylarkCallable(name = "interrupted_function", documented = false)
+  public Runtime.NoneType interruptedFunction() throws InterruptedException {
+    throw new InterruptedException();
+  }
+
+  private static final NativeProvider<NativeInfoMock> CONSTRUCTOR =
+      new NativeProvider<NativeInfoMock>(NativeInfoMock.class, "native_info_mock") {};
 
   @SkylarkModule(name = "Mock", doc = "")
-  static class NativeInfoMock extends NativeInfo {
-
-    private static final NativeProvider<NativeInfoMock> CONSTRUCTOR =
-        new NativeProvider<NativeInfoMock>(NativeInfoMock.class, "native_info_mock") {};
+  class NativeInfoMock extends NativeInfo {
 
     public NativeInfoMock() {
       super(CONSTRUCTOR);
@@ -110,8 +103,8 @@
     }
 
     @SkylarkCallable(name = "struct_field_callable", documented = false, structField = true)
-    public BuiltinFunction structFieldCallable() {
-      return foobar;
+    public BuiltinCallable structFieldCallable() {
+      return CallUtils.getBuiltinCallable(SkylarkEvaluationTest.this, "foobar");
     }
 
     @SkylarkCallable(
@@ -126,7 +119,7 @@
   }
 
   @SkylarkModule(name = "Mock", doc = "")
-  static class Mock implements SkylarkValue {
+  class Mock implements SkylarkValue {
     @SkylarkCallable(
         name = "MockFn",
         selfCall = true,
@@ -171,9 +164,10 @@
         + (sem != null)
         + ")";
     }
+
     @SkylarkCallable(name = "struct_field_callable", documented = false, structField = true)
-    public BuiltinFunction structFieldCallable() {
-      return foobar;
+    public Object structFieldCallable() {
+      return CallUtils.getBuiltinCallable(SkylarkEvaluationTest.this, "foobar");
     }
 
     @SkylarkCallable(name = "interrupted_struct_field", documented = false, structField = true)
@@ -521,7 +515,7 @@
   }
 
   @SkylarkModule(name = "MockSubClass", doc = "")
-  static final class MockSubClass extends Mock implements MockInterface {
+  final class MockSubClass extends Mock implements MockInterface {
     @Override
     public Boolean isEmpty(String str) {
       return str.isEmpty();
@@ -1298,8 +1292,6 @@
 
   @Test
   public void testStructAccessAsFuncall() throws Exception {
-    foobar.configureFromAnnotation(
-        getClass().getDeclaredField("foobar").getAnnotation(SkylarkSignature.class));
     new SkylarkTest()
         .update("mock", new Mock())
         .setUp("v = mock.struct_field_callable()")
@@ -1314,9 +1306,7 @@
 
   @Test
   public void testCallingInterruptedFunction() throws Exception {
-    interruptedFunction.configureFromAnnotation(
-        getClass().getDeclaredField("interruptedFunction").getAnnotation(SkylarkSignature.class));
-    update("interrupted_function", interruptedFunction);
+    update("interrupted_function", CallUtils.getBuiltinCallable(this, "interrupted_function"));
     assertThrows(InterruptedException.class, () -> eval("interrupted_function()"));
   }