Replaces JavaSerializableCodec with DynamicCodec as the default

* Skylark serialization was previously dropping location in error, which this fixes.
* Deletes a lot of codecs with fidelity issues (DynamicCodec has full fidelity).
* Deletes EnumRuntimeCodec which can now be replaced with the superior EnumCodec.
* This should eventually allow us to delete Serializable from all Blaze. The remaining blocker is NoSuchPackageExceptionCodec.

PiperOrigin-RevId: 191603929

37 files changed, 266 insertions, 240 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java
index e6e6e9c637..5ad5007e96 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java
@@ -71,7 +71,6 @@ import com.google.devtools.build.lib.packages.SkylarkProvider;
 import com.google.devtools.build.lib.packages.TargetUtils;
 import com.google.devtools.build.lib.packages.TestSize;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.ParamType;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
@@ -879,7 +878,6 @@ public class SkylarkRuleClassFunctions {
    *
    * <p>Exactly one of {@link #builder} or {@link #ruleClass} is null except inside {@link #export}.
    */
-  @AutoCodec
   public static final class SkylarkRuleFunction extends BaseFunction
       implements SkylarkExportable, RuleFunction {
     private RuleClass.Builder builder;
@@ -903,14 +901,8 @@ public class SkylarkRuleClassFunctions {
     }
 
     /** This is for post-export reconstruction for serialization. */
-    @VisibleForSerialization
-    @AutoCodec.Instantiator
-    SkylarkRuleFunction(
-        RuleClass ruleClass,
-        RuleClassType type,
-        Location definitionLocation,
-        Label skylarkLabel
-    ) {
+    private SkylarkRuleFunction(
+        RuleClass ruleClass, RuleClassType type, Location definitionLocation, Label skylarkLabel) {
       super("rule", FunctionSignature.KWARGS);
       Preconditions.checkNotNull(
           ruleClass,
diff --git a/src/main/java/com/google/devtools/build/lib/packages/SkylarkProvider.java b/src/main/java/com/google/devtools/build/lib/packages/SkylarkProvider.java
index 0de9e682e7..95e64d9c7a 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/SkylarkProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/SkylarkProvider.java
@@ -44,7 +44,6 @@ import javax.annotation.Nullable;
  * pre-exported provider directly. Exported providers use only their key for {@link #equals} and
  * {@link #hashCode}.
  */
-@AutoCodec
 public class SkylarkProvider extends Provider implements SkylarkExportable {
 
   private static final FunctionSignature.WithValues<Object, SkylarkType> SCHEMALESS_SIGNATURE =
@@ -126,9 +125,7 @@ public class SkylarkProvider extends Provider implements SkylarkExportable {
    * <p>If {@code key} is null, the provider is unexported. If {@code fields} is null, the provider
    * is schemaless.
    */
-  @AutoCodec.Instantiator
-  @AutoCodec.VisibleForSerialization
-  SkylarkProvider(
+  private SkylarkProvider(
       @Nullable SkylarkKey key, @Nullable ImmutableList<String> fields, Location location) {
     // We override getName() in order to use the name that is assigned when export() is called.
     // Hence BaseFunction's constructor gets a null name.
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java
index 3533ce071d..18dd2de19d 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java
@@ -85,7 +85,6 @@ import java.util.UUID;
 import javax.annotation.Nullable;
 
 /** Action that represents some kind of C++ compilation step. */
-@AutoCodec
 @ThreadCompatible
 public class CppCompileAction extends AbstractAction
     implements IncludeScannable, ExecutionInfoSpecifier, CommandAction {
@@ -346,7 +345,6 @@ public class CppCompileAction extends AbstractAction
     Preconditions.checkArgument(!shouldPruneModules || shouldScanIncludes);
   }
 
-  @AutoCodec.Instantiator
   @VisibleForSerialization
   CppCompileAction(
       ActionOwner owner,
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/AutoRegistry.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/AutoRegistry.java
index bf11b86e69..4af9f532f0 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/AutoRegistry.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/AutoRegistry.java
@@ -14,8 +14,10 @@
 
 package com.google.devtools.build.lib.skyframe.serialization;
 
+import com.google.common.base.Predicates;
 import com.google.common.base.Supplier;
 import com.google.common.base.Suppliers;
+import com.google.common.collect.ImmutableList;
 import java.io.IOException;
 
 /**
@@ -29,15 +31,35 @@ public class AutoRegistry {
   private static final Supplier<ObjectCodecRegistry> SUPPLIER =
       Suppliers.memoize(AutoRegistry::create);
 
+  /* Common ancestor of common.google.devtools.build and com.google.devtools.common.options,
+   * where Tristate lives. */
+  private static final String PACKAGE_PREFIX = "com.google.devtools";
+
+  /** Classes outside {@link AutoRegistry#PACKAGE_PREFIX} that need to be serialized. */
+  private static final ImmutableList<String> EXTERNAL_CLASS_NAMES_TO_REGISTER =
+      ImmutableList.of("java.io.FileNotFoundException", "java.io.IOException");
+
+  private static final ImmutableList<Object> CONSTANTS_TO_REGISTER =
+      ImmutableList.of(
+          Predicates.alwaysTrue(),
+          Predicates.alwaysFalse(),
+          Predicates.isNull(),
+          Predicates.notNull());
+
   public static ObjectCodecRegistry get() {
     return SUPPLIER.get();
   }
 
   private static ObjectCodecRegistry create() {
     try {
-      return CodecScanner.initializeCodecRegistry("com.google.devtools.build")
-          .setAllowDefaultCodec(false)
-          .build();
+      ObjectCodecRegistry.Builder registry = CodecScanner.initializeCodecRegistry(PACKAGE_PREFIX);
+      for (String className : EXTERNAL_CLASS_NAMES_TO_REGISTER) {
+        registry.addClassName(className);
+      }
+      for (Object constant : CONSTANTS_TO_REGISTER) {
+        registry.addConstant(constant);
+      }
+      return registry.build();
     } catch (IOException | ReflectiveOperationException e) {
       throw new IllegalStateException(e);
     }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/CodecScanner.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/CodecScanner.java
index 635b5ad755..319e0c1152 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/CodecScanner.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/CodecScanner.java
@@ -27,11 +27,8 @@ import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashSet;
-import java.util.List;
-import java.util.function.Predicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 /**
@@ -59,62 +56,73 @@ public class CodecScanner {
     log.info("Building ObjectCodecRegistry");
     ArrayList<Class<? extends ObjectCodec<?>>> codecs = new ArrayList<>();
     ArrayList<Class<? extends CodecRegisterer<?>>> registerers = new ArrayList<>();
-    List<ClassInfo> classInfos = getClassInfos(packagePrefix).collect(Collectors.toList());
-    getCodecs(classInfos)
-        .forEach(
-            type -> {
-              if (!ObjectCodec.class.equals(type)
-                  && ObjectCodec.class.isAssignableFrom(type)
-                  && !Modifier.isAbstract(type.getModifiers())) {
-                codecs.add((Class<? extends ObjectCodec<?>>) type);
-              } else if (!CodecRegisterer.class.equals(type)
-                  && CodecRegisterer.class.isAssignableFrom(type)) {
-                registerers.add((Class<? extends CodecRegisterer<?>>) type);
-              }
-            });
     ObjectCodecRegistry.Builder builder = ObjectCodecRegistry.newBuilder();
-    getMatchingClasses(
-            classInfos,
-            classInfo ->
-                classInfo
-                    .getSimpleName()
-                    .endsWith(CodecScanningConstants.REGISTERED_SINGLETON_SUFFIX))
+    getClassInfos(packagePrefix)
         .forEach(
-            type -> {
-              if (!RegisteredSingletonDoNotUse.class.isAssignableFrom(type)) {
-                return;
-              }
-              Field field;
-              try {
-                field =
-                    type.getDeclaredField(
-                        CodecScanningConstants.REGISTERED_SINGLETON_INSTANCE_VAR_NAME);
-              } catch (NoSuchFieldException e) {
-                throw new IllegalStateException(
-                    type
-                        + " inherits from "
-                        + RegisteredSingletonDoNotUse.class
-                        + " but does not have a field "
-                        + CodecScanningConstants.REGISTERED_SINGLETON_INSTANCE_VAR_NAME,
-                    e);
-              }
-              try {
-                builder.addConstant(
-                    Preconditions.checkNotNull(field.get(null), "%s %s", field, type));
-              } catch (IllegalAccessException e) {
-                throw new IllegalStateException(
-                    "Could not access field " + field + " for " + type, e);
+            classInfo -> {
+              if (classInfo.getName().endsWith("Codec")) {
+                processLikelyCodec(classInfo.load(), codecs);
+              } else if (classInfo.getName().endsWith("CodecRegisterer")) {
+                processLikelyRegisterer(classInfo.load(), registerers);
+              } else if (classInfo
+                  .getName()
+                  .endsWith(CodecScanningConstants.REGISTERED_SINGLETON_SUFFIX)) {
+                processLikelyConstant(classInfo.load(), builder);
+              } else {
+                // Assumes that anything with a class name matching the above won't need to be
+                // serialized.
+                builder.addClassName(classInfo.getName().intern());
               }
             });
 
     HashSet<Class<? extends ObjectCodec<?>>> alreadyRegistered =
         runRegisterers(builder, registerers);
-
     applyDefaultRegistration(builder, alreadyRegistered, codecs);
     return builder;
   }
 
   @SuppressWarnings("unchecked")
+  private static void processLikelyCodec(
+      Class<?> type, ArrayList<Class<? extends ObjectCodec<?>>> codecs) {
+    if (!ObjectCodec.class.equals(type)
+        && ObjectCodec.class.isAssignableFrom(type)
+        && !Modifier.isAbstract(type.getModifiers())) {
+      codecs.add((Class<? extends ObjectCodec<?>>) type);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  private static void processLikelyRegisterer(
+      Class<?> type, ArrayList<Class<? extends CodecRegisterer<?>>> registerers) {
+    if (!CodecRegisterer.class.equals(type) && CodecRegisterer.class.isAssignableFrom(type)) {
+      registerers.add((Class<? extends CodecRegisterer<?>>) type);
+    }
+  }
+
+  private static void processLikelyConstant(Class<?> type, ObjectCodecRegistry.Builder builder) {
+    if (!RegisteredSingletonDoNotUse.class.isAssignableFrom(type)) {
+      return;
+    }
+    Field field;
+    try {
+      field = type.getDeclaredField(CodecScanningConstants.REGISTERED_SINGLETON_INSTANCE_VAR_NAME);
+    } catch (NoSuchFieldException e) {
+      throw new IllegalStateException(
+          type
+              + " inherits from "
+              + RegisteredSingletonDoNotUse.class
+              + " but does not have a field "
+              + CodecScanningConstants.REGISTERED_SINGLETON_INSTANCE_VAR_NAME,
+          e);
+    }
+    try {
+      builder.addConstant(Preconditions.checkNotNull(field.get(null), "%s %s", field, type));
+    } catch (IllegalAccessException e) {
+      throw new IllegalStateException("Could not access field " + field + " for " + type, e);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
   private static HashSet<Class<? extends ObjectCodec<?>>> runRegisterers(
       ObjectCodecRegistry.Builder builder,
       ArrayList<Class<? extends CodecRegisterer<?>>> registerers)
@@ -195,19 +203,4 @@ public class CodecScanner {
         .filter(c -> c.getPackageName().startsWith(packagePrefix))
         .sorted(Comparator.comparing(ClassInfo::getName));
   }
-
-  /**
-   * Returns a stream of likely codec and registerer implementations.
-   *
-   * <p>Caller should do additional checks as this method only performs string matching.
-   */
-  private static Stream<Class<?>> getCodecs(List<ClassInfo> classInfos) {
-    return getMatchingClasses(
-        classInfos, c -> c.getName().endsWith("Codec") || c.getName().endsWith("CodecRegisterer"));
-  }
-
-  private static Stream<Class<?>> getMatchingClasses(
-      List<ClassInfo> classInfos, Predicate<ClassInfo> predicate) {
-    return classInfos.stream().filter(predicate).map(ClassInfo::load);
-  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/EnumRuntimeCodec.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/EnumRuntimeCodec.java
deleted file mode 100644
index 0d67591077..0000000000
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/EnumRuntimeCodec.java
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright 2018 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.skyframe.serialization;
-
-import com.google.protobuf.CodedInputStream;
-import com.google.protobuf.CodedOutputStream;
-import java.io.IOException;
-
-@SuppressWarnings("rawtypes")
-class EnumRuntimeCodec implements ObjectCodec<Enum> {
-
-  @Override
-  public Class<Enum> getEncodedClass() {
-    return Enum.class;
-  }
-
-  @Override
-  public void serialize(SerializationContext context, Enum value, CodedOutputStream codedOut)
-      throws IOException, SerializationException {
-    context.serialize(value.getDeclaringClass(), codedOut);
-    codedOut.writeInt32NoTag(value.ordinal());
-  }
-
-  @Override
-  public Enum deserialize(DeserializationContext context, CodedInputStream codedIn)
-      throws SerializationException, IOException {
-    Class<? extends Enum> enumType = context.deserialize(codedIn);
-    return enumType.getEnumConstants()[codedIn.readInt32()];
-  }
-}
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/ObjectCodecRegistry.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/ObjectCodecRegistry.java
index 95590143db..c963172e9f 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/ObjectCodecRegistry.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/ObjectCodecRegistry.java
@@ -16,15 +16,18 @@ package com.google.devtools.build.lib.skyframe.serialization;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
+import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSortedSet;
 import com.google.protobuf.CodedInputStream;
 import com.google.protobuf.CodedOutputStream;
 import java.io.IOException;
 import java.util.Comparator;
 import java.util.IdentityHashMap;
 import java.util.Map;
+import java.util.function.Supplier;
 import javax.annotation.Nullable;
 
 /**
@@ -38,19 +41,27 @@ public class ObjectCodecRegistry {
     return new Builder();
   }
 
+  private final boolean allowDefaultCodec;
+
   private final ImmutableMap<Class<?>, CodecDescriptor> classMappedCodecs;
   private final ImmutableList<CodecDescriptor> tagMappedCodecs;
-  @Nullable
-  private final CodecDescriptor defaultCodecDescriptor;
 
+  private final int constantsStartTag;
   private final IdentityHashMap<Object, Integer> constantsMap;
   private final ImmutableList<Object> constants;
-  private final int constantsStartTag;
+
+  /** This is sorted, but we need index-based access. */
+  private final ImmutableList<String> classNames;
+
+  private final IdentityHashMap<String, Supplier<CodecDescriptor>> dynamicCodecs;
 
   private ObjectCodecRegistry(
       ImmutableSet<ObjectCodec<?>> memoizingCodecs,
       ImmutableList<Object> constants,
+      ImmutableSortedSet<String> classNames,
       boolean allowDefaultCodec) {
+    this.allowDefaultCodec = allowDefaultCodec;
+
     int nextTag = 1; // 0 is reserved for null.
     ImmutableMap.Builder<Class<?>, CodecDescriptor> memoizingCodecsBuilder =
         ImmutableMap.builderWithExpectedSize(memoizingCodecs.size());
@@ -60,14 +71,6 @@ public class ObjectCodecRegistry {
         processCodecs(
             memoizingCodecs, nextTag, tagMappedMemoizingCodecsBuilder, memoizingCodecsBuilder);
 
-    this.defaultCodecDescriptor =
-        allowDefaultCodec
-            ? new TypedCodecDescriptor<>(nextTag++, new JavaSerializableCodec())
-            : null;
-    if (allowDefaultCodec) {
-      tagMappedMemoizingCodecsBuilder.add(defaultCodecDescriptor);
-    }
-
     this.classMappedCodecs = memoizingCodecsBuilder.build();
     this.tagMappedCodecs = tagMappedMemoizingCodecsBuilder.build();
 
@@ -77,16 +80,35 @@ public class ObjectCodecRegistry {
       constantsMap.put(constant, nextTag++);
     }
     this.constants = constants;
+
+    this.classNames = classNames.asList();
+    this.dynamicCodecs = createDynamicCodecs(classNames, nextTag);
+  }
+
+  public CodecDescriptor getCodecDescriptorForObject(Object obj)
+      throws SerializationException.NoCodecException {
+    Class<?> type = obj.getClass();
+    CodecDescriptor descriptor = getCodecDescriptor(type);
+    if (descriptor != null) {
+      return descriptor;
+    }
+    if (!allowDefaultCodec) {
+      throw new SerializationException.NoCodecException(
+          "No codec available for " + type + " and default fallback disabled");
+    }
+    if (obj instanceof Enum) {
+      // Enums must be serialized using declaring class.
+      type = ((Enum) obj).getDeclaringClass();
+    }
+    return getDynamicCodecDescriptor(type.getName());
   }
 
   /**
-   * Returns a {@link CodecDescriptor} for the given type.
+   * Returns a {@link CodecDescriptor} for the given type or null if none found.
    *
-   * <p>Falls back to a codec for the nearest super type of type. Failing that, may fall back to the
-   * registry's default codec.
+   * <p>Also checks if there are codecs for a superclass of the given type.
    */
-  public CodecDescriptor getCodecDescriptor(Class<?> type)
-      throws SerializationException.NoCodecException {
+  private @Nullable CodecDescriptor getCodecDescriptor(Class<?> type) {
     // TODO(blaze-team): consider caching this traversal.
     for (Class<?> nextType = type; nextType != null; nextType = nextType.getSuperclass()) {
       CodecDescriptor result = classMappedCodecs.get(nextType);
@@ -94,11 +116,7 @@ public class ObjectCodecRegistry {
         return result;
       }
     }
-    if (defaultCodecDescriptor == null) {
-      throw new SerializationException.NoCodecException(
-          "No codec available for " + type + " and default fallback disabled");
-    }
-    return defaultCodecDescriptor;
+    return null;
   }
 
   @Nullable
@@ -116,17 +134,20 @@ public class ObjectCodecRegistry {
   /** Returns the {@link CodecDescriptor} associated with the supplied tag. */
   public CodecDescriptor getCodecDescriptorByTag(int tag)
       throws SerializationException.NoCodecException {
-    int tagOffset = tag - 1;
-    if (tagOffset < 0 || tagOffset > tagMappedCodecs.size()) {
+    int tagOffset = tag - 1; // 0 reserved for null
+    if (tagOffset < 0) {
       throw new SerializationException.NoCodecException("No codec available for tag " + tag);
     }
+    if (tagOffset < tagMappedCodecs.size()) {
+      return tagMappedCodecs.get(tagOffset);
+    }
 
-    CodecDescriptor result = tagMappedCodecs.get(tagOffset);
-    if (result != null) {
-      return result;
-    } else {
+    tagOffset -= tagMappedCodecs.size();
+    tagOffset -= constants.size();
+    if (!allowDefaultCodec || tagOffset < 0 || tagOffset >= classNames.size()) {
       throw new SerializationException.NoCodecException("No codec available for tag " + tag);
     }
+    return getDynamicCodecDescriptor(classNames.get(tagOffset));
   }
 
   /**
@@ -137,7 +158,7 @@ public class ObjectCodecRegistry {
   @VisibleForTesting
   public Builder getBuilder() {
     Builder builder = newBuilder();
-    builder.setAllowDefaultCodec(defaultCodecDescriptor != null);
+    builder.setAllowDefaultCodec(allowDefaultCodec);
     for (Map.Entry<Class<?>, CodecDescriptor> entry : classMappedCodecs.entrySet()) {
       builder.add(entry.getValue().getCodec());
     }
@@ -145,9 +166,17 @@ public class ObjectCodecRegistry {
     for (Object constant : constants) {
       builder.addConstant(constant);
     }
+
+    for (String className : classNames) {
+      builder.addClassName(className);
+    }
     return builder;
   }
 
+  ImmutableList<String> classNames() {
+    return classNames;
+  }
+
   /** Describes encoding logic. */
   interface CodecDescriptor {
     void serialize(SerializationContext context, Object obj, CodedOutputStream codedOut)
@@ -157,7 +186,7 @@ public class ObjectCodecRegistry {
         throws IOException, SerializationException;
 
     /**
-     * Unique identifier identifying the associated codec.
+     * Unique identifier for the associated codec.
      *
      * <p>Intended to be used as a compact on-the-wire representation of an encoded object's type.
      *
@@ -214,6 +243,7 @@ public class ObjectCodecRegistry {
   public static class Builder {
     private final ImmutableSet.Builder<ObjectCodec<?>> codecBuilder = ImmutableSet.builder();
     private final ImmutableList.Builder<Object> constantsBuilder = ImmutableList.builder();
+    private final ImmutableSortedSet.Builder<String> classNames = ImmutableSortedSet.naturalOrder();
     private boolean allowDefaultCodec = true;
 
     public Builder add(ObjectCodec<?> codec) {
@@ -234,9 +264,14 @@ public class ObjectCodecRegistry {
       return this;
     }
 
+    public Builder addClassName(String className) {
+      classNames.add(className);
+      return this;
+    }
+
     public ObjectCodecRegistry build() {
       return new ObjectCodecRegistry(
-          codecBuilder.build(), constantsBuilder.build(), allowDefaultCodec);
+          codecBuilder.build(), constantsBuilder.build(), classNames.build(), allowDefaultCodec);
     }
   }
 
@@ -257,4 +292,51 @@ public class ObjectCodecRegistry {
     }
     return nextTag;
   }
+
+  private static IdentityHashMap<String, Supplier<CodecDescriptor>> createDynamicCodecs(
+      ImmutableSortedSet<String> classNames, int nextTag) {
+    IdentityHashMap<String, Supplier<CodecDescriptor>> dynamicCodecs =
+        new IdentityHashMap<>(classNames.size());
+    for (String className : classNames) {
+      int tag = nextTag++;
+      dynamicCodecs.put(
+          className, Suppliers.memoize(() -> createDynamicCodecDescriptor(tag, className)));
+    }
+    return dynamicCodecs;
+  }
+
+  /** For enums, this method must only be called for the declaring class. */
+  private static CodecDescriptor createDynamicCodecDescriptor(int tag, String className) {
+    try {
+      Class<?> type = Class.forName(className);
+      if (type.isEnum()) {
+        return createCodecDescriptorForEnum(tag, type);
+      }
+      return new TypedCodecDescriptor<>(tag, new DynamicCodec(Class.forName(className)));
+    } catch (ReflectiveOperationException e) {
+      new SerializationException("Could not create codec for type: " + className, e)
+          .printStackTrace();
+      return null;
+    }
+  }
+
+  @SuppressWarnings({"unchecked", "rawtypes"})
+  private static CodecDescriptor createCodecDescriptorForEnum(int tag, Class<?> enumType) {
+    return new TypedCodecDescriptor(tag, new EnumCodec(enumType));
+  }
+
+  private CodecDescriptor getDynamicCodecDescriptor(String className)
+      throws SerializationException.NoCodecException {
+    Supplier<CodecDescriptor> supplier = dynamicCodecs.get(className);
+    if (supplier == null) {
+      throw new SerializationException.NoCodecException(
+          "No default codec available for " + className);
+    }
+    CodecDescriptor descriptor = supplier.get();
+    if (descriptor == null) {
+      throw new SerializationException.NoCodecException(
+          "There was a problem creating a codec for " + className + " check logs for details.");
+    }
+    return descriptor;
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/SerializationContext.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/SerializationContext.java
index e06d6dba45..ba5b696128 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/SerializationContext.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/SerializationContext.java
@@ -118,7 +118,7 @@ public class SerializationContext {
     if (writeNullOrConstant(object, codedOut)) {
       return null;
     }
-    ObjectCodecRegistry.CodecDescriptor descriptor = registry.getCodecDescriptor(object.getClass());
+    ObjectCodecRegistry.CodecDescriptor descriptor = registry.getCodecDescriptorForObject(object);
     codedOut.writeSInt32NoTag(descriptor.getTag());
     return descriptor;
   }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/testutils/NotSerializableCodec.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/testutils/NotSerializableCodec.java
new file mode 100644
index 0000000000..f8b5617670
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/testutils/NotSerializableCodec.java
@@ -0,0 +1,49 @@
+// Copyright 2018 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.skyframe.serialization.testutils;
+
+import com.google.devtools.build.lib.skyframe.serialization.DeserializationContext;
+import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec;
+import com.google.devtools.build.lib.skyframe.serialization.SerializationContext;
+import com.google.protobuf.CodedInputStream;
+import com.google.protobuf.CodedOutputStream;
+import java.io.NotSerializableException;
+
+/** A testing helper to force serialization errors. */
+public class NotSerializableCodec implements ObjectCodec<Object> {
+  private final Class<?> type;
+
+  public NotSerializableCodec(Class<?> type) {
+    this.type = type;
+  }
+
+  @Override
+  public Class<?> getEncodedClass() {
+    return type;
+  }
+
+  @Override
+  public void serialize(
+      SerializationContext unusedContext, Object unusedObj, CodedOutputStream unusedCodedOut)
+      throws NotSerializableException {
+    throw new NotSerializableException(type + " marked not serializable");
+  }
+
+  @Override
+  public Object deserialize(DeserializationContext unusedContext, CodedInputStream unusedCodedIn)
+      throws NotSerializableException {
+    throw new NotSerializableException(type + " marked not serializable");
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Argument.java b/src/main/java/com/google/devtools/build/lib/syntax/Argument.java
index 141f763e50..a4d782a44f 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Argument.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Argument.java
@@ -14,7 +14,6 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.common.base.Preconditions;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.List;
 import javax.annotation.Nullable;
@@ -75,7 +74,6 @@ public abstract class Argument extends ASTNode {
   }
 
   /** positional argument: Expression */
-  @AutoCodec
   public static final class Positional extends Passed {
 
     public Positional(Expression value) {
@@ -94,7 +92,6 @@ public abstract class Argument extends ASTNode {
   }
 
   /** keyword argument: K = Expression */
-  @AutoCodec
   public static final class Keyword extends Passed {
 
     final String name;
@@ -123,7 +120,6 @@ public abstract class Argument extends ASTNode {
   }
 
   /** positional rest (starred) argument: *Expression */
-  @AutoCodec
   public static final class Star extends Passed {
 
     public Star(Expression value) {
@@ -143,7 +139,6 @@ public abstract class Argument extends ASTNode {
   }
 
   /** keyword rest (star_starred) parameter: **Expression */
-  @AutoCodec
   public static final class StarStar extends Passed {
 
     public StarStar(Expression value) {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java
index 2286f44d2a..4545b7cc81 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java
@@ -14,11 +14,9 @@
 
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for an assignment statement. */
-@AutoCodec
 public final class AssignmentStatement extends Statement {
 
   private final LValue lvalue;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java
index d23d78467c..ec23b20f86 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java
@@ -14,11 +14,9 @@
 
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for an augmented assignment statement. */
-@AutoCodec
 public final class AugmentedAssignmentStatement extends Statement {
 
   private final Operator operator;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BinaryOperatorExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/BinaryOperatorExpression.java
index b56c9ebc90..b1f835ce63 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BinaryOperatorExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BinaryOperatorExpression.java
@@ -15,7 +15,6 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.base.Strings;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.syntax.Concatable.Concatter;
 import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
 import com.google.devtools.build.lib.syntax.SkylarkList.Tuple;
@@ -23,7 +22,6 @@ import java.io.IOException;
 import java.util.IllegalFormatException;
 
 /** Syntax node for a binary operator expression. */
-@AutoCodec
 public final class BinaryOperatorExpression extends Expression {
 
   private final Expression lhs;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java
index 0f016b9c58..769762895e 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java
@@ -13,11 +13,9 @@
 // limitations under the License.
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for an if/else expression. */
-@AutoCodec
 public final class ConditionalExpression extends Expression {
 
   // Python conditional expressions: $thenCase if $condition else $elseCase
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java b/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java
index f1125568e3..f47b80020b 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java
@@ -15,13 +15,11 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.base.Preconditions;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
 
 /** Syntax node for dictionary comprehension expressions. */
-@AutoCodec
 public final class DictComprehension extends AbstractComprehension {
   private final Expression keyExpression;
   private final Expression valueExpression;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/DictionaryLiteral.java b/src/main/java/com/google/devtools/build/lib/syntax/DictionaryLiteral.java
index 410408c060..76512d855b 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/DictionaryLiteral.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/DictionaryLiteral.java
@@ -15,16 +15,13 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.List;
 
 /** Syntax node for dictionary literals. */
-@AutoCodec
 public final class DictionaryLiteral extends Expression {
 
   /** Node for an individual key-value pair in a dictionary literal. */
-  @AutoCodec
   public static final class DictionaryEntryLiteral extends ASTNode {
 
     private final Expression key;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/DotExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/DotExpression.java
index 5b1045f4d4..86313c132c 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/DotExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/DotExpression.java
@@ -15,14 +15,12 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.collect.Streams;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.syntax.FuncallExpression.MethodDescriptor;
 import com.google.devtools.build.lib.util.SpellChecker;
 import java.io.IOException;
 import java.util.Optional;
 
 /** Syntax node for a dot expression. e.g. obj.field, but not obj.method() */
-@AutoCodec
 public final class DotExpression extends Expression {
 
   private final Expression object;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java
index 971e72dd40..d0d2c22609 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java
@@ -14,11 +14,9 @@
 
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for a function call statement. Used for build rules. */
-@AutoCodec
 public final class ExpressionStatement extends Statement {
 
   private final Expression expression;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java
index 71ffe661ca..b060b78c31 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java
@@ -13,11 +13,9 @@
 // limitations under the License.
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** A class for flow statements (e.g. break and continue) */
-@AutoCodec
 public final class FlowStatement extends Statement {
   // TODO(laurentlb): This conflicts with Statement.Kind, maybe remove it?
   public enum Kind {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java
index d2e06a033d..cdf23d7340 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java
@@ -15,12 +15,10 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.List;
 
 /** Syntax node for a for loop statement. */
-@AutoCodec
 public final class ForStatement extends Statement {
 
   private final LValue variable;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
index ff81eade53..7a807f5e20 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
@@ -26,7 +26,6 @@ import com.google.common.collect.ImmutableSortedMap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skylarkinterface.Param;
 import com.google.devtools.build.lib.skylarkinterface.ParamType;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
@@ -54,7 +53,6 @@ import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 
 /** Syntax node for a function call expression. */
-@AutoCodec
 public final class FuncallExpression extends Expression {
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java
index 5d856ede75..0c78eaf1e5 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java
@@ -14,11 +14,9 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for a function definition. */
-@AutoCodec
 public final class FunctionDefStatement extends Statement {
 
   private final Identifier identifier;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Identifier.java b/src/main/java/com/google/devtools/build/lib/syntax/Identifier.java
index 419cc99621..db4a62dab0 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Identifier.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Identifier.java
@@ -14,7 +14,6 @@
 
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.util.SpellChecker;
 import java.io.IOException;
 import java.util.Set;
@@ -34,7 +33,6 @@ import javax.annotation.Nullable;
  * Object#hashCode} (but note that these methods ignore location information). They are needed
  * because {@code Identifier}s are stored in maps when constructing {@link LoadStatement}.
  */
-@AutoCodec
 public final class Identifier extends Expression {
 
   private final String name;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java
index b4377d0531..15e0087843 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java
@@ -15,12 +15,10 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.List;
 
 /** Syntax node for an if/else statement. */
-@AutoCodec
 public final class IfStatement extends Statement {
 
   /**
@@ -29,7 +27,6 @@ public final class IfStatement extends Statement {
    * <p>This extends Statement, but it is not actually an independent statement in the grammar. We
    * should probably eliminate it in favor of a recursive representation of if/else chains.
    */
-  @AutoCodec
   public static final class ConditionalStatements extends Statement {
 
     private final Expression condition;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/IndexExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/IndexExpression.java
index 0c4a7f628c..efb1a64edf 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/IndexExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/IndexExpression.java
@@ -14,7 +14,6 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /**
@@ -22,7 +21,6 @@ import java.io.IOException;
  * obj[from:to]}). The object may be either a sequence or an associative mapping (most commonly
  * lists and dictionaries).
  */
-@AutoCodec
 public final class IndexExpression extends Expression {
 
   private final Expression object;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/IntegerLiteral.java b/src/main/java/com/google/devtools/build/lib/syntax/IntegerLiteral.java
index b642dd8649..3f2653caf6 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/IntegerLiteral.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/IntegerLiteral.java
@@ -13,11 +13,9 @@
 // limitations under the License.
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for an integer literal. */
-@AutoCodec
 public final class IntegerLiteral extends Expression {
   private final int value;
 
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/LValue.java b/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
index 34ccaa8b36..eb3c685063 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
@@ -17,7 +17,6 @@ package com.google.devtools.build.lib.syntax;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
 import java.io.IOException;
 import java.util.Collection;
@@ -45,7 +44,6 @@ import java.util.Collection;
  * cannot appear in {@code LValue}s.
  */
 // TODO(bazel-team): Add support for assigning to slices (e.g. a[2:6] = [3]).
-@AutoCodec
 public final class LValue extends ASTNode {
 
   private final Expression expr;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java b/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java
index 8141bd9cd9..7a7e0c59b4 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java
@@ -15,14 +15,12 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.base.Preconditions;
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
 /** Syntax node for lists comprehension expressions. */
-@AutoCodec
 public final class ListComprehension extends AbstractComprehension {
   private final Expression outputExpression;
 
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ListLiteral.java b/src/main/java/com/google/devtools/build/lib/syntax/ListLiteral.java
index ac367201e8..e18d419ecd 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ListLiteral.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ListLiteral.java
@@ -13,7 +13,6 @@
 // limitations under the License.
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
 import com.google.devtools.build.lib.syntax.SkylarkList.Tuple;
 import java.io.IOException;
@@ -27,7 +26,6 @@ import java.util.List;
  * <p>(Note that during evaluation, both list and tuple values are represented by java.util.List
  * objects, the only difference between them being whether or not they are mutable.)
  */
-@AutoCodec
 public final class ListLiteral extends Expression {
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java
index c9669fcd56..087333cdd5 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java
@@ -15,12 +15,10 @@ package com.google.devtools.build.lib.syntax;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.Map;
 
 /** Syntax node for an import statement. */
-@AutoCodec
 public final class LoadStatement extends Statement {
 
   private final ImmutableMap<Identifier, String> symbolMap;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/PassStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/PassStatement.java
index f7854e8dda..e0351002ef 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/PassStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/PassStatement.java
@@ -14,11 +14,9 @@
 
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for a `pass` statement. */
-@AutoCodec
 public class PassStatement extends Statement {
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java
index 37d462964b..4d9c2ad20c 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java
@@ -14,12 +14,10 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import javax.annotation.Nullable;
 
 /** A wrapper Statement class for return expressions. */
-@AutoCodec
 public final class ReturnStatement extends Statement {
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkType.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkType.java
index b4729ace56..9e394d977d 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkType.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkType.java
@@ -146,64 +146,62 @@ public abstract class SkylarkType implements Serializable {
   // Notable types
 
   /** A singleton for the TOP type, that at analysis time means that any type is possible. */
-  public static final Simple TOP = new Top();
+  @AutoCodec public static final Simple TOP = new Top();
 
   /** A singleton for the BOTTOM type, that contains no element */
-  public static final Simple BOTTOM = new Bottom();
+  @AutoCodec public static final Simple BOTTOM = new Bottom();
 
   /** NONE, the Unit type, isomorphic to Void, except its unique element prints as None */
   // Note that we currently consider at validation time that None is in every type,
   // by declaring its type as TOP instead of NONE, even though at runtime,
   // we reject None from all types but NONE, and in particular from e.g. lists of Files.
   // TODO(bazel-team): resolve this inconsistency, one way or the other.
-  public static final Simple NONE = Simple.forClass(Runtime.NoneType.class);
+  @AutoCodec public static final Simple NONE = Simple.forClass(Runtime.NoneType.class);
 
   /** The STRING type, for strings */
-  public static final Simple STRING = Simple.forClass(String.class);
+  @AutoCodec public static final Simple STRING = Simple.forClass(String.class);
 
   /** The INTEGER type, for 32-bit signed integers */
-  public static final Simple INT = Simple.forClass(Integer.class);
+  @AutoCodec public static final Simple INT = Simple.forClass(Integer.class);
 
   /** The BOOLEAN type, that contains TRUE and FALSE */
-  public static final Simple BOOL = Simple.forClass(Boolean.class);
+  @AutoCodec public static final Simple BOOL = Simple.forClass(Boolean.class);
 
   /** The FUNCTION type, that contains all functions, otherwise dynamically typed at call-time */
+  @AutoCodec
   public static final SkylarkFunctionType FUNCTION = new SkylarkFunctionType("unknown", TOP);
 
   /** The DICT type, that contains SkylarkDict */
-  public static final Simple DICT = Simple.forClass(SkylarkDict.class);
+  @AutoCodec public static final Simple DICT = Simple.forClass(SkylarkDict.class);
 
   /** The SEQUENCE type, that contains lists and tuples */
   // TODO(bazel-team): this was added for backward compatibility with the BUILD language,
   // that doesn't make a difference between list and tuple, so that functions can be declared
   // that keep not making the difference. Going forward, though, we should investigate whether
   // we ever want to use this type, and if not, make sure no existing client code uses it.
-  public static final Simple SEQUENCE = Simple.forClass(SkylarkList.class);
+  @AutoCodec public static final Simple SEQUENCE = Simple.forClass(SkylarkList.class);
 
   /** The LIST type, that contains all MutableList-s */
-  public static final Simple LIST = Simple.forClass(MutableList.class);
+  @AutoCodec public static final Simple LIST = Simple.forClass(MutableList.class);
 
   /** The TUPLE type, that contains all Tuple-s */
-  public static final Simple TUPLE = Simple.forClass(Tuple.class);
+  @AutoCodec public static final Simple TUPLE = Simple.forClass(Tuple.class);
 
   /** The STRING_LIST type, a MutableList of strings */
-  public static final SkylarkType STRING_LIST = Combination.of(LIST, STRING);
+  @AutoCodec public static final SkylarkType STRING_LIST = Combination.of(LIST, STRING);
 
   /** The INT_LIST type, a MutableList of integers */
-  public static final SkylarkType INT_LIST = Combination.of(LIST, INT);
+  @AutoCodec public static final SkylarkType INT_LIST = Combination.of(LIST, INT);
 
   /** The SET type, that contains all SkylarkNestedSet-s, and the generic combinator for them */
-  public static final Simple SET = Simple.forClass(SkylarkNestedSet.class);
+  @AutoCodec public static final Simple SET = Simple.forClass(SkylarkNestedSet.class);
 
   // Common subclasses of SkylarkType
 
   /** the Top type contains all objects */
-  @AutoCodec
-  @VisibleForSerialization
-  static class Top extends Simple {
+  private static class Top extends Simple {
 
-    @VisibleForSerialization
-    Top() {
+    private Top() {
       super(Object.class);
     }
 
@@ -219,12 +217,9 @@ public abstract class SkylarkType implements Serializable {
   }
 
   /** the Bottom type contains no element */
-  @AutoCodec
-  @VisibleForSerialization
-  static class Bottom extends Simple {
+  private static class Bottom extends Simple {
 
-    @VisibleForSerialization
-    Bottom() {
+    private Bottom() {
       super(Empty.class);
     }
 
@@ -237,12 +232,11 @@ public abstract class SkylarkType implements Serializable {
   }
 
   /** a Simple type contains the instance of a Java class */
-  @AutoCodec
-  public static class Simple extends SkylarkType {
+  @VisibleForSerialization
+  static class Simple extends SkylarkType {
     private final Class<?> type;
 
-    @VisibleForSerialization
-    Simple(Class<?> type) {
+    private Simple(Class<?> type) {
       this.type = type;
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SliceExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/SliceExpression.java
index f4074e9499..54c194a021 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SliceExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SliceExpression.java
@@ -14,13 +14,11 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 import java.util.List;
 import javax.annotation.Nullable;
 
 /** Syntax node for a slice expression, e.g. obj[:len(obj):2]. */
-@AutoCodec
 public final class SliceExpression extends Expression {
 
   private final Expression object;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/StringLiteral.java b/src/main/java/com/google/devtools/build/lib/syntax/StringLiteral.java
index db1c23a289..b88bbb1e0d 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/StringLiteral.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/StringLiteral.java
@@ -13,11 +13,9 @@
 // limitations under the License.
 package com.google.devtools.build.lib.syntax;
 
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for a string literal. */
-@AutoCodec
 public final class StringLiteral extends Expression {
   String value;
 
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/UnaryOperatorExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/UnaryOperatorExpression.java
index 08fcf457b9..824333a9d8 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/UnaryOperatorExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/UnaryOperatorExpression.java
@@ -14,11 +14,9 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.devtools.build.lib.events.Location;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import java.io.IOException;
 
 /** Syntax node for a unary operator expression. */
-@AutoCodec
 public final class UnaryOperatorExpression extends Expression {
 
   private final UnaryOperator operator;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/UserDefinedFunction.java b/src/main/java/com/google/devtools/build/lib/syntax/UserDefinedFunction.java
index fb60ca6df0..eda6c3d0b8 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/UserDefinedFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/UserDefinedFunction.java
@@ -18,7 +18,6 @@ import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.profiler.Profiler;
 import com.google.devtools.build.lib.profiler.ProfilerTask;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
 import com.google.devtools.build.lib.syntax.Environment.LexicalFrame;
 
@@ -26,7 +25,6 @@ import com.google.devtools.build.lib.syntax.Environment.LexicalFrame;
  * The actual function registered in the environment. This function is defined in the parsed code
  * using {@link FunctionDefStatement}.
  */
-@AutoCodec
 public class UserDefinedFunction extends BaseFunction {
 
   private final ImmutableList<Statement> statements;