Add stubs for GeneratedMessageV3, RepeatedFieldBuilderV3, SingleFieldBuilderV3 for compatibility with older <4.26.x gencode.

These classes are deprecated and will be removed in the next breaking change. Users should update gencode to >= 4.26.x which uses GeneratedMessage instead of GeneratedMessageV3.

Tested with //compatibility:java_conformance_v3.25.0 which builds the runtime against 3.25.0 gencode.

PiperOrigin-RevId: 644136172

Author: zhangskz

.github/workflows/test_java.yml

@@ -22,19 +22,19 @@ jobs:
             image: us-docker.pkg.dev/protobuf-build/containers/test/linux/java:8-1fdbb997433cb22c1e49ef75ad374a8d6bb88702
             # TODO: b/318555165 - enable the layering check. Currently it does
             # not work correctly with the toolchain in this Docker image.
-            targets: //java/... //java/internal:java_version --features=-layering_check
+            targets: //java/... //java/internal:java_version //compatibility/... --features=-layering_check
           - name: OpenJDK 11
             version: '11'
             image: us-docker.pkg.dev/protobuf-build/containers/test/linux/java:11-1fdbb997433cb22c1e49ef75ad374a8d6bb88702
-            targets: //java/... //java/internal:java_version
+            targets: //java/... //java/internal:java_version //compatibility/...
           - name: OpenJDK 17
             version: '17'
             image: us-docker.pkg.dev/protobuf-build/containers/test/linux/java:17-1fdbb997433cb22c1e49ef75ad374a8d6bb88702
-            targets: //java/... //java/internal:java_version
+            targets: //java/... //java/internal:java_version //compatibility/...
           - name: aarch64
             version: 'aarch64'
             image: us-docker.pkg.dev/protobuf-build/containers/test/linux/emulation:aarch64-63dd26c0c7a808d92673a3e52e848189d4ab0f17
-            targets: //java/... //src/google/protobuf/compiler:protoc_aarch64_test
+            targets: //java/... //compatibility/... //src/google/protobuf/compiler:protoc_aarch64_test
 
     name: Linux ${{ matrix.name }}
     runs-on: ubuntu-latest

compatibility/BUILD.bazel

@@ -16,5 +16,4 @@ java_runtime_conformance(
 java_runtime_conformance(
     name = "java_conformance_v3.25.0",
     gencode_version = "3.25.0",
-    tags = ["manual"],
 )

java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java

@@ -0,0 +1,86 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+package com.google.protobuf;
+
+import java.util.List;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.Extension.ExtensionType;
+import com.google.protobuf.GeneratedMessage.ExtendableMessageOrBuilder;
+import com.google.protobuf.GeneratedMessage.ExtensionDescriptorRetriever;
+import com.google.protobuf.GeneratedMessage.FieldAccessorTable;
+
+/**
+ * Stub for GeneratedMessageV3 wrapping GeneratedMessage for compatibility with older gencode.
+ *
+ * @deprecated This class is deprecated, and slated for removal in the next Java breaking change
+ *     (5.x in 2025 Q1). Users should update gencode to >= 4.26.x which uses GeneratedMessage
+ *     instead of GeneratedMessageV3.
+ */
+@Deprecated
+public abstract class GeneratedMessageV3 extends GeneratedMessage {
+  private static final long serialVersionUID = 1L;
+
+  protected GeneratedMessageV3() {
+    super();
+  }
+
+  protected GeneratedMessageV3(Builder<?> builder) {
+    super(builder);
+  }
+
+  /**
+   * Stub for GeneratedMessageV3.ExtendableBuilder wrapping GeneratedMessage.ExtendableBuilder for
+   * compatibility with older gencode.
+   *
+   * @deprecated This class is deprecated, and slated for removal in the next Java breaking change
+   *     (5.x in 2025 Q1). Users should update gencode to >= 4.26.x which uses
+   *     GeneratedMessage.ExtendableBuilder instead of GeneratedMessageV3.ExtendableBuilder.
+   */
+  @Deprecated
+  public abstract static class ExtendableBuilder<
+          MessageT extends ExtendableMessage<MessageT>,
+          BuilderT extends ExtendableBuilder<MessageT, BuilderT>>
+      extends GeneratedMessage.ExtendableBuilder<MessageT, BuilderT>
+      implements ExtendableMessageOrBuilder<MessageT> {
+    protected ExtendableBuilder() {
+      super();
+    }
+
+    protected ExtendableBuilder(BuilderParent parent) {
+      super(parent);
+    }
+
+    // Support old gencode override method removed in cl/597677225
+    public <T> BuilderT setExtension(
+        final GeneratedMessage.GeneratedExtension<MessageT, T> extension, final T value) {
+      return setExtension((ExtensionLite<MessageT, T>) extension, value);
+    }
+
+    // Support old gencode override method removed in cl/597677225
+    public <T> BuilderT setExtension(
+        final GeneratedMessage.GeneratedExtension<MessageT, List<T>> extension,
+        final int index,
+        final T value) {
+      return setExtension((ExtensionLite<MessageT, List<T>>) extension, index, value);
+    }
+
+    // Support old gencode override method removed in cl/597677225
+    public <T> BuilderT addExtension(
+        final GeneratedMessage.GeneratedExtension<MessageT, List<T>> extension, final T value) {
+      return addExtension((ExtensionLite<MessageT, List<T>>) extension, value);
+    }
+
+    // Support old gencode override method removed in cl/597677225
+    public <T> BuilderT clearExtension(
+        final GeneratedMessage.GeneratedExtension<MessageT, T> extension) {
+      return clearExtension((ExtensionLite<MessageT, T>) extension);
+    }
+  }
+}

java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilderV3.java

@@ -0,0 +1,34 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+package com.google.protobuf;
+
+import java.util.List;
+
+/**
+ * Stub for RepeatedFieldBuilderV3 wrapping RepeatedFieldBuilder for compatibility with older
+ * gencode.
+ *
+ * @deprecated This class is deprecated, and slated for removal in the next breaking change. Users
+ *     should update gencode to >= 4.26.x which replaces RepeatedFieldBuilderV3 with
+ *     RepeatedFieldBuilder.
+ */
+@Deprecated
+public class RepeatedFieldBuilderV3<
+        MType extends GeneratedMessage,
+        BType extends GeneratedMessage.Builder,
+        IType extends MessageOrBuilder>
+    extends RepeatedFieldBuilder<MType, BType, IType> {
+
+  public RepeatedFieldBuilderV3(
+      List<MType> messages,
+      boolean isMessagesListMutable,
+      GeneratedMessage.BuilderParent parent,
+      boolean isClean) {
+    super(messages, isMessagesListMutable, parent, isClean);
+  }
+}

java/core/src/main/java/com/google/protobuf/SingleFieldBuilderV3.java

@@ -0,0 +1,30 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+package com.google.protobuf;
+
+import static com.google.protobuf.Internal.checkNotNull;
+
+/**
+ * Stub for SingleFieldBuilderV3 wrapping SingleFieldBuilder for compatibility with older gencode.
+ *
+ * @deprecated This class is deprecated, and slated for removal in the next breaking change. Users
+ *     should update gencode to >= 4.26.x which replaces SingleFieldBuilderV3 with
+ *     SingleFieldBuilder.
+ */
+@Deprecated
+public class SingleFieldBuilderV3<
+        MType extends GeneratedMessage,
+        BType extends GeneratedMessage.Builder,
+        IType extends MessageOrBuilder>
+    extends SingleFieldBuilder<MType, BType, IType> {
+
+  public SingleFieldBuilderV3(
+      MType message, GeneratedMessage.BuilderParent parent, boolean isClean) {
+    super(message, parent, isClean);
+  }
+}