Prepare methods in RuntimeVersion for Protobuf Java cross-domain version validation. No changes to Protobuf Java gencode yet.

PiperOrigin-RevId: 587025016

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

@@ -7,6 +7,8 @@
 
 package com.google.protobuf;
 
+import java.util.logging.Logger;
+
 /**
  * Provides the version of this Protobuf Java runtime, and methods for Protobuf Java gencode to
  * validate that versions are compatible. Fields and methods in this class should be only accessed
@@ -29,6 +31,31 @@ public final class RuntimeVersion {
   public static final String SUFFIX = "-dev";
   private static final String VERSION_STRING = versionString(MAJOR, MINOR, PATCH, SUFFIX);
 
+  /**
+   * Validates that the gencode is in the same domain as the runtime.
+   *
+   * <p>This method will be directly called by the google-internal gencode to verify no cross-domain
+   * usages.
+   *
+   * @param gencodeDomain the domain where Protobuf Java code was generated.
+   * @throws ProtobufRuntimeVersionException if gencodeDomain is not the same as DOMAIN.
+   */
+  public static void validateProtobufGencodeDomain(RuntimeDomain gencodeDomain) {
+    // Check the environmental variable, and temporarily disable validation if it's set to true.
+    String disableFlag = java.lang.System.getenv("TEMORARILY_DISABLE_PROTOBUF_VERSION_CHECK");
+    if ((disableFlag != null && disableFlag.equals("true"))) {
+      return;
+    }
+
+    if (gencodeDomain != DOMAIN) {
+      throw new ProtobufRuntimeVersionException(
+          String.format(
+              "Mismatched Protobuf Gencode/Runtime domains: gencode %s, runtime %s. Cross-domain"
+                  + " usage of Protobuf is not supported.",
+              gencodeDomain, DOMAIN));
+    }
+  }
+
   /**
    * Validates that the gencode version is compatible with this runtime version according to
    * https://protobuf.dev/support/cross-version-runtime-guarantee/.
@@ -37,7 +64,7 @@ public final class RuntimeVersion {
    *
    * <p>This method is only for Protobuf Java gencode; do not call it elsewhere.
    *
-   * @param domain the domain where Protobuf Java code was generated. Currently ignored.
+   * @param domain the domain where Protobuf Java code was generated.
    * @param major the major version of Protobuf Java gencode.
    * @param minor the minor version of Protobuf Java gencode.
    * @param patch the micro/patch version of Protobuf Java gencode.
@@ -47,18 +74,14 @@ public final class RuntimeVersion {
   public static void validateProtobufGencodeVersion(
       RuntimeDomain domain, int major, int minor, int patch, String suffix) {
 
-    // Check the environmental variable, and temporarily disable poison pills if it's set to true.
-    String disableFlag = java.lang.System.getenv("TEMORARILY_DISABLE_PROTOBUF_VERSION_CHECK");
-    if (disableFlag != null && disableFlag.equals("true")) {
-      return;
-    }
-
     // Check that version numbers are valid.
     if (major < 0 || minor < 0 || patch < 0) {
       throw new ProtobufRuntimeVersionException(
           "Invalid gencode version: " + versionString(major, minor, patch, suffix));
     }
 
+    validateProtobufGencodeDomain(domain);
+
     String gencodeVersionString = versionString(major, minor, patch, suffix);
     // Check that runtime major version is the same as the gencode major version.
     if (major != MAJOR) {

java/core/src/test/java/com/google/protobuf/RuntimeVersionTest.java

@@ -24,12 +24,26 @@ public final class RuntimeVersionTest {
             RuntimeVersion.ProtobufRuntimeVersionException.class,
             () ->
                 RuntimeVersion.validateProtobufGencodeVersion(
-                    RuntimeVersion.DOMAIN,
-                    -1,
-                    RuntimeVersion.MINOR,
-                    RuntimeVersion.PATCH,
-                    RuntimeVersion.SUFFIX));
-    assertThat(thrown).hasMessageThat().contains("Invalid gencode version: -1");
+                    RuntimeVersion.DOMAIN, 1, -2, -3, ""));
+    assertThat(thrown).hasMessageThat().contains("Invalid gencode version: 1.-2.-3");
+  }
+
+  @Test
+  public void versionValidation_crossDomainDisallowed() {
+
+    RuntimeVersion.RuntimeDomain gencodeDomain = RuntimeVersion.RuntimeDomain.GOOGLE_INTERNAL;
+    RuntimeVersion.ProtobufRuntimeVersionException thrown =
+        assertThrows(
+            RuntimeVersion.ProtobufRuntimeVersionException.class,
+            () -> RuntimeVersion.validateProtobufGencodeDomain(gencodeDomain));
+    assertThat(thrown).hasMessageThat().contains("Mismatched Protobuf Gencode/Runtime domains");
+  }
+
+  @Test
+  public void versionValidation_sameDomainAllowed() {
+
+    RuntimeVersion.RuntimeDomain gencodeDomain = RuntimeVersion.RuntimeDomain.PUBLIC;
+    RuntimeVersion.validateProtobufGencodeDomain(gencodeDomain);
   }
 
   @Test