1 files changed, 26 insertions, 27 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
index 38cbb7c35f..4bec1c6012 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
@@ -29,12 +29,12 @@ import com.google.devtools.build.lib.util.Pair;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.util.SpellChecker;
 import com.google.devtools.common.options.Options;
-import java.io.Serializable;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.TreeSet;
 import javax.annotation.Nullable;
@@ -295,38 +295,20 @@ public final class Environment implements Freezable {
     }
   }
 
-  // TODO(bazel-team): Eliminate this hack around Java serialization. The bindings are currently
-  // factored out into BaseExtension, which is non-Serializable, and which has a default constructor
-  // that does not initialize any bindings. This means that when Extension is Java-serialized, all
-  // the bindings are simply lost.
-  private static class BaseExtension {
-
-    protected final ImmutableMap<String, Object> bindings;
-
-    BaseExtension(Map<String, Object> bindings) {
-      this.bindings = ImmutableMap.copyOf(bindings);
-    }
-
-    // Hack to "allow" java serialization.
-    BaseExtension() {
-      this.bindings = ImmutableMap.of();
-    }
-  }
-
   /** An Extension to be imported with load() into a BUILD or .bzl file. */
   @Immutable
-  public static final class Extension extends BaseExtension implements Serializable {
+  public static final class Extension {
+
+    private final ImmutableMap<String, Object> bindings;
 
     /**
      * Cached hash code for the transitive content of this {@code Extension} and its dependencies.
      */
     private final String transitiveContentHashCode;
 
-    /**
-     * Constructs with the given hash code and bindings.
-     */
-    public Extension(Map<String, Object> bindings, String transitiveContentHashCode) {
-      super(bindings);
+    /** Constructs with the given hash code and bindings. */
+    public Extension(ImmutableMap<String, Object> bindings, String transitiveContentHashCode) {
+      this.bindings = bindings;
       this.transitiveContentHashCode = transitiveContentHashCode;
     }
 
@@ -335,8 +317,7 @@ public final class Environment implements Freezable {
      * and that {@code Environment}'s transitive hash code.
      */
     public Extension(Environment env) {
-      super(env.globalFrame.bindings);
-      this.transitiveContentHashCode = env.getTransitiveContentHashCode();
+      this(ImmutableMap.copyOf(env.globalFrame.bindings), env.getTransitiveContentHashCode());
     }
 
     public String getTransitiveContentHashCode() {
@@ -346,6 +327,24 @@ public final class Environment implements Freezable {
     public ImmutableMap<String, Object> getBindings() {
       return bindings;
     }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (this == obj) {
+        return true;
+      }
+      if (!(obj instanceof Extension)) {
+        return false;
+      }
+      Extension other = (Extension) obj;
+      return transitiveContentHashCode.equals(other.getTransitiveContentHashCode())
+          && bindings.equals(other.getBindings());
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(bindings, transitiveContentHashCode);
+    }
   }
 
   /**