Add Kotlin class name helpers to names.h

protobuf-github-bot · copybara-github · commit 527b2ab41e78 · 2025-07-07T13:56:49.000-07:00
This change exposes helper functions to generate the fully qualified Kotlin factory name for a protobuf message.

PiperOrigin-RevId: 780246910
diff --git a/src/google/protobuf/compiler/java/name_resolver.cc b/src/google/protobuf/compiler/java/name_resolver.cc
@@ -354,6 +354,19 @@ std::string ClassNameResolver::GetKotlinFactoryName(
   return IsForbiddenKotlin(name) ? absl::StrCat(name, "_") : name;
 }
 
+std::string ClassNameResolver::GetFullyQualifiedKotlinFactoryName(
+    const Descriptor* descriptor) {
+  if (descriptor->containing_type() != nullptr) {
+    return absl::StrCat(
+        GetKotlinExtensionsClassName(descriptor->containing_type()), ".",
+        GetKotlinFactoryName(descriptor));
+  } else {
+    return absl::StrCat(
+        GetFileJavaPackage(descriptor->file(), /*immutable=*/true), ".",
+        GetKotlinFactoryName(descriptor));
+  }
+}
+
 std::string ClassNameResolver::GetJavaImmutableClassName(
     const Descriptor* descriptor) {
   return GetJavaClassFullName(ClassNameWithoutPackage(descriptor, true),
diff --git a/src/google/protobuf/compiler/java/name_resolver.h b/src/google/protobuf/compiler/java/name_resolver.h
@@ -99,6 +99,7 @@ class PROTOC_EXPORT ClassNameResolver {
   std::string GetJavaImmutableClassName(const EnumDescriptor* descriptor);
   std::string GetJavaImmutableClassName(const ServiceDescriptor* descriptor);
   std::string GetKotlinFactoryName(const Descriptor* descriptor);
+  std::string GetFullyQualifiedKotlinFactoryName(const Descriptor* descriptor);
   std::string GetKotlinExtensionsClassName(const Descriptor* descriptor);
   std::string GetKotlinExtensionsClassNameEscaped(const Descriptor* descriptor);
   std::string GetFileJavaPackage(const FileDescriptor* file, bool immutable);
diff --git a/src/google/protobuf/compiler/java/name_resolver_test.cc b/src/google/protobuf/compiler/java/name_resolver_test.cc
@@ -242,6 +242,8 @@ TEST_F(NameResolverTest, MultipleFilesMessageEdition2023) {
             PACKAGE_PREFIX "proto2_unittest.FooMessage");
   EXPECT_EQ(resolver.GetJavaImmutableClassName(message_descriptor),
             PACKAGE_PREFIX "proto2_unittest.FooMessage");
+  EXPECT_EQ(resolver.GetFullyQualifiedKotlinFactoryName(message_descriptor),
+            PACKAGE_PREFIX "proto2_unittest.fooMessage");
 }
 
 TEST_F(NameResolverTest, SingleFileMessageEdition2023) {
@@ -262,6 +264,8 @@ TEST_F(NameResolverTest, SingleFileMessageEdition2023) {
             PACKAGE_PREFIX "proto2_unittest.Foo.FooMessage");
   EXPECT_EQ(resolver.GetJavaImmutableClassName(message_descriptor),
             PACKAGE_PREFIX "proto2_unittest.Foo$FooMessage");
+  EXPECT_EQ(resolver.GetFullyQualifiedKotlinFactoryName(message_descriptor),
+            PACKAGE_PREFIX "proto2_unittest.fooMessage");
 }
 
 TEST_F(NameResolverTest, NestInFileClassMessageEdition2024) {
@@ -307,6 +311,14 @@ TEST_F(NameResolverTest, NestInFileClassMessageEdition2024) {
   EXPECT_EQ(resolver.GetJavaImmutableClassName(nested_in_unnested_message),
             PACKAGE_PREFIX
             "proto2_unittest.UnnestedMessage$NestedInUnnestedMessage");
+  EXPECT_EQ(resolver.GetFullyQualifiedKotlinFactoryName(unnested_message),
+            PACKAGE_PREFIX "proto2_unittest.unnestedMessage");
+  EXPECT_EQ(resolver.GetFullyQualifiedKotlinFactoryName(nested_in_file_message),
+            PACKAGE_PREFIX "proto2_unittest.nestedInFileClassMessage");
+  EXPECT_EQ(
+      resolver.GetFullyQualifiedKotlinFactoryName(nested_in_unnested_message),
+      PACKAGE_PREFIX
+      "proto2_unittest.UnnestedMessageKt.nestedInUnnestedMessage");
 }
 
 TEST_F(NameResolverTest, MultipleFilesEnumEdition2023) {
diff --git a/src/google/protobuf/compiler/java/names.cc b/src/google/protobuf/compiler/java/names.cc
@@ -160,6 +160,23 @@ std::string UnderscoresToCamelCaseCheckReserved(const FieldDescriptor* field) {
   return name;
 }
 
+PROTOC_EXPORT std::string KotlinFactoryName(const Descriptor* descriptor) {
+  ClassNameResolver name_resolver;
+  return name_resolver.GetKotlinFactoryName(descriptor);
+}
+
+PROTOC_EXPORT std::string FullyQualifiedKotlinFactoryName(
+    const Descriptor* descriptor) {
+  ClassNameResolver name_resolver;
+  return name_resolver.GetFullyQualifiedKotlinFactoryName(descriptor);
+}
+
+PROTOC_EXPORT std::string KotlinExtensionsClassName(
+    const Descriptor* descriptor) {
+  ClassNameResolver name_resolver;
+  return name_resolver.GetKotlinExtensionsClassName(descriptor);
+}
+
 
 }  // namespace java
 }  // namespace compiler
diff --git a/src/google/protobuf/compiler/java/names.h b/src/google/protobuf/compiler/java/names.h
@@ -132,6 +132,28 @@ PROTOC_EXPORT std::string UnderscoresToCamelCaseCheckReserved(
 PROTOC_EXPORT std::string UnderscoresToCapitalizedCamelCase(
     const FieldDescriptor* field);
 
+// Requires:
+//   descriptor != NULL
+// Returns:
+//   The unqualified Kotlin factory name.
+PROTOC_EXPORT std::string KotlinFactoryName(const Descriptor* descriptor);
+
+// Requires:
+//   descriptor != NULL
+// Returns:
+//   The fully qualified Kotlin factory name.
+PROTOC_EXPORT std::string FullyQualifiedKotlinFactoryName(
+    const Descriptor* descriptor);
+
+// Requires:
+//   descriptor != NULL
+// Returns:
+//   The fully qualified Kotlin extensions class name. "Extensions" in this case
+//   refers to "Extensions" the Kotlin concept, not "Extensions" the Protobuf
+//   concept
+PROTOC_EXPORT std::string KotlinExtensionsClassName(
+    const Descriptor* descriptor);
+
 
 }  // namespace java
 }  // namespace compiler
