Fix unpacking any messages containing extension fields

PiperOrigin-RevId: 574248821

bundle/src/main/java/dev/cel/bundle/CelBuilder.java

@@ -20,6 +20,7 @@
 import com.google.protobuf.DescriptorProtos.FileDescriptorSet;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import dev.cel.checker.ProtoTypeMask;
 import dev.cel.checker.TypeProvider;
@@ -282,6 +283,13 @@ public interface CelBuilder {
   @CanIgnoreReturnValue
   CelBuilder addRuntimeLibraries(Iterable<CelRuntimeLibrary> libraries);
 
+  /**
+   * Sets a proto ExtensionRegistry to assist with unpacking Any messages containing a proto2
+   extension field.
+   */
+  @CanIgnoreReturnValue
+  CelBuilder setExtensionRegistry(ExtensionRegistry extensionRegistry);
+
   /** Construct a new {@code Cel} instance from the provided configuration. */
   Cel build();
 }

bundle/src/main/java/dev/cel/bundle/CelImpl.java

@@ -25,6 +25,7 @@
 import com.google.protobuf.DescriptorProtos.FileDescriptorSet;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import dev.cel.checker.CelCheckerBuilder;
 import dev.cel.checker.ProtoTypeMask;
@@ -339,6 +340,13 @@ public Builder addRuntimeLibraries(Iterable<CelRuntimeLibrary> libraries) {
       return this;
     }
 
+    @Override
+    public CelBuilder setExtensionRegistry(ExtensionRegistry extensionRegistry) {
+      checkNotNull(extensionRegistry);
+      runtimeBuilder.setExtensionRegistry(extensionRegistry);
+      return this;
+    }
+
     @Override
     public Cel build() {
       return new CelImpl(

common/src/main/java/dev/cel/common/internal/DefaultDescriptorPool.java

@@ -46,7 +46,10 @@ public final class DefaultDescriptorPool implements CelDescriptorPool {
 
   /** A DefaultDescriptorPool instance with just well known types loaded. */
   public static final DefaultDescriptorPool INSTANCE =
-      new DefaultDescriptorPool(WELL_KNOWN_TYPE_DESCRIPTORS, ImmutableMultimap.of());
+      new DefaultDescriptorPool(
+          WELL_KNOWN_TYPE_DESCRIPTORS,
+          ImmutableMultimap.of(),
+          ExtensionRegistry.getEmptyRegistry());
 
   // K: Fully qualified message type name, V: Message descriptor
   private final ImmutableMap<String, Descriptor> descriptorMap;
@@ -55,7 +58,15 @@ public final class DefaultDescriptorPool implements CelDescriptorPool {
   // V: Field descriptor for the extension message
   private final ImmutableMultimap<String, FieldDescriptor> extensionDescriptorMap;
 
+  @SuppressWarnings("Immutable") // ExtensionRegistry is immutable, just not marked as such.
+  private final ExtensionRegistry extensionRegistry;
+
   public static DefaultDescriptorPool create(CelDescriptors celDescriptors) {
+    return create(celDescriptors, ExtensionRegistry.getEmptyRegistry());
+  }
+
+  public static DefaultDescriptorPool create(
+      CelDescriptors celDescriptors, ExtensionRegistry extensionRegistry) {
     Map<String, Descriptor> descriptorMap = new HashMap<>(); // Using a hashmap to allow deduping
     stream(WellKnownProto.values()).forEach(d -> descriptorMap.put(d.typeName(), d.descriptor()));
 
@@ -64,7 +75,9 @@ public static DefaultDescriptorPool create(CelDescriptors celDescriptors) {
     }
 
     return new DefaultDescriptorPool(
-        ImmutableMap.copyOf(descriptorMap), celDescriptors.extensionDescriptors());
+        ImmutableMap.copyOf(descriptorMap),
+        celDescriptors.extensionDescriptors(),
+        extensionRegistry);
   }
 
   @Override
@@ -83,14 +96,15 @@ public Optional<FieldDescriptor> findExtensionDescriptor(
 
   @Override
   public ExtensionRegistry getExtensionRegistry() {
-    // TODO: Populate one from runtime builder.
-    return ExtensionRegistry.getEmptyRegistry();
+    return extensionRegistry;
   }
 
   private DefaultDescriptorPool(
       ImmutableMap<String, Descriptor> descriptorMap,
-      ImmutableMultimap<String, FieldDescriptor> extensionDescriptorMap) {
+      ImmutableMultimap<String, FieldDescriptor> extensionDescriptorMap,
+      ExtensionRegistry extensionRegistry) {
     this.descriptorMap = checkNotNull(descriptorMap);
     this.extensionDescriptorMap = checkNotNull(extensionDescriptorMap);
+    this.extensionRegistry = checkNotNull(extensionRegistry);
   }
 }

extensions/src/test/java/dev/cel/extensions/CelProtoExtensionsTest.java

@@ -19,10 +19,14 @@
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.protobuf.Any;
 import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.ExtensionRegistry;
 import com.google.testing.junit.testparameterinjector.TestParameter;
 import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import com.google.testing.junit.testparameterinjector.TestParameters;
+import dev.cel.bundle.Cel;
+import dev.cel.bundle.CelFactory;
 import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelFunctionDecl;
 import dev.cel.common.CelOverloadDecl;
@@ -277,6 +281,29 @@ public void getExt_nonProtoNamespace_success(String expr) throws Exception {
     assertThat(result).isTrue();
   }
 
+  @Test
+  public void getExt_onAnyPackedExtensionField_success() throws Exception {
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    MessagesProto2Extensions.registerAllExtensions(extensionRegistry);
+    Cel cel =
+        CelFactory.standardCelBuilder()
+            .addCompilerLibraries(CelExtensions.protos())
+            .addFileTypes(MessagesProto2Extensions.getDescriptor())
+            .setExtensionRegistry(extensionRegistry)
+            .addVar(
+                "msg", StructTypeReference.create("dev.cel.testing.testdata.proto2.Proto2Message"))
+            .build();
+    CelAbstractSyntaxTree ast =
+        cel.compile("proto.getExt(msg, dev.cel.testing.testdata.proto2.int32_ext)").getAst();
+    Any anyMsg =
+        Any.pack(
+            Proto2Message.newBuilder().setExtension(MessagesProto2Extensions.int32Ext, 1).build());
+
+    Long result = (Long) cel.createProgram(ast).eval(ImmutableMap.of("msg", anyMsg));
+
+    assertThat(result).isEqualTo(1);
+  }
+
   private enum ParseErrorTestCase {
     FIELD_NOT_FULLY_QUALIFIED(
         "proto.getExt(Proto2ExtensionScopedMessage{}, int64_ext)",

runtime/src/main/java/dev/cel/runtime/CelRuntimeBuilder.java

@@ -19,6 +19,7 @@
 import com.google.protobuf.DescriptorProtos.FileDescriptorSet;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import dev.cel.common.CelOptions;
 import java.util.function.Function;
@@ -149,6 +150,13 @@ public interface CelRuntimeBuilder {
   @CanIgnoreReturnValue
   CelRuntimeBuilder addLibraries(Iterable<? extends CelRuntimeLibrary> libraries);
 
+  /**
+   * Sets a proto ExtensionRegistry to assist with unpacking Any messages containing a proto2
+   extension field.
+   */
+  @CanIgnoreReturnValue
+  CelRuntimeBuilder setExtensionRegistry(ExtensionRegistry extensionRegistry);
+
   /** Build a new instance of the {@code CelRuntime}. */
   @CheckReturnValue
   CelRuntime build();

runtime/src/main/java/dev/cel/runtime/CelRuntimeLegacyImpl.java

@@ -25,6 +25,7 @@
 import com.google.protobuf.DescriptorProtos.FileDescriptorSet;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelDescriptorUtil;
@@ -79,6 +80,7 @@ public static final class Builder implements CelRuntimeBuilder {
 
     private boolean standardEnvironmentEnabled;
     private Function<String, Message.Builder> customTypeFactory;
+    private ExtensionRegistry extensionRegistry;
 
     @Override
     @CanIgnoreReturnValue
@@ -161,6 +163,14 @@ public Builder addLibraries(Iterable<? extends CelRuntimeLibrary> libraries) {
       return this;
     }
 
+    @Override
+    @CanIgnoreReturnValue
+    public Builder setExtensionRegistry(ExtensionRegistry extensionRegistry) {
+      checkNotNull(extensionRegistry);
+      this.extensionRegistry = extensionRegistry.getUnmodifiable();
+      return this;
+    }
+
     /** Build a new {@code CelRuntimeLegacyImpl} instance from the builder config. */
     @Override
     @CanIgnoreReturnValue
@@ -171,6 +181,7 @@ public CelRuntimeLegacyImpl build() {
       CelDescriptorPool celDescriptorPool =
           newDescriptorPool(
               fileTypes.build(),
+              extensionRegistry,
               options);
 
       @SuppressWarnings("Immutable")
@@ -214,14 +225,15 @@ public CelRuntimeLegacyImpl build() {
 
     private static CelDescriptorPool newDescriptorPool(
         ImmutableSet<FileDescriptor> fileTypeSet,
+        ExtensionRegistry extensionRegistry,
         CelOptions celOptions) {
       CelDescriptors celDescriptors =
           CelDescriptorUtil.getAllDescriptorsFromFileDescriptor(
               fileTypeSet, celOptions.resolveTypeDependencies());
 
       ImmutableList.Builder<CelDescriptorPool> descriptorPools = new ImmutableList.Builder<>();
 
-      descriptorPools.add(DefaultDescriptorPool.create(celDescriptors));
+      descriptorPools.add(DefaultDescriptorPool.create(celDescriptors, extensionRegistry));
 
       return CombinedDescriptorPool.create(descriptorPools.build());
     }
@@ -241,6 +253,7 @@ private Builder() {
       this.fileTypes = ImmutableSet.builder();
       this.functionBindings = ImmutableMap.builder();
       this.celRuntimeLibraries = ImmutableSet.builder();
+      this.extensionRegistry = ExtensionRegistry.getEmptyRegistry();
       this.customTypeFactory = null;
     }
   }