Editions: Migrate string_field_validation to a C++ feature

Every language has very different handling of utf8 validation.  Any with proto2/proto3 differences will receive language-specific features for edition zero to better model these subtle differences.

PiperOrigin-RevId: 557258923

src/google/protobuf/compiler/command_line_interface_unittest.cc

@@ -1560,7 +1560,6 @@ TEST_F(CommandLineInterfaceTest, Plugin_RuntimeFeatures) {
       EqualsProto(R"pb(field_presence: IMPLICIT
                        enum_type: OPEN
                        repeated_field_encoding: PACKED
-                       string_field_validation: MANDATORY
                        message_encoding: LENGTH_PREFIXED
                        json_format: ALLOW
                        raw_features { field_presence: IMPLICIT }
@@ -1577,7 +1576,6 @@ TEST_F(CommandLineInterfaceTest, Plugin_RuntimeFeatures) {
               EqualsProto(R"pb(field_presence: IMPLICIT
                                enum_type: OPEN
                                repeated_field_encoding: PACKED
-                               string_field_validation: MANDATORY
                                message_encoding: LENGTH_PREFIXED
                                json_format: ALLOW
                                raw_features { field_presence: IMPLICIT }

src/google/protobuf/compiler/cpp/generator.cc

@@ -101,6 +101,17 @@ absl::flat_hash_map<absl::string_view, std::string> CommonVars(
   };
 }
 
+static bool IsStringMapType(const FieldDescriptor& field) {
+  if (!field.is_map()) return false;
+  for (int i = 0; i < field.message_type()->field_count(); ++i) {
+    if (field.message_type()->field(i)->type() ==
+        FieldDescriptor::TYPE_STRING) {
+      return true;
+    }
+  }
+  return false;
+}
+
 }  // namespace
 
 bool CppGenerator::Generate(const FileDescriptor* file,
@@ -356,12 +367,6 @@ absl::Status CppGenerator::ValidateFeatures(const FileDescriptor* file) const {
   google::protobuf::internal::VisitDescriptors(*file, [&](const FieldDescriptor& field) {
     const FeatureSet& source_features = GetSourceFeatures(field);
     const FeatureSet& raw_features = GetSourceRawFeatures(field);
-    if (raw_features.GetExtension(::pb::cpp).has_legacy_closed_enum() &&
-        field.cpp_type() != FieldDescriptor::CPPTYPE_ENUM) {
-      status = absl::FailedPreconditionError(absl::StrCat(
-          "Field ", field.full_name(),
-          " specifies the legacy_closed_enum feature but has non-enum type."));
-    }
     if (field.enum_type() != nullptr &&
         source_features.GetExtension(::pb::cpp).legacy_closed_enum() &&
         source_features.field_presence() == FeatureSet::IMPLICIT) {
@@ -369,6 +374,37 @@ absl::Status CppGenerator::ValidateFeatures(const FileDescriptor* file) const {
           absl::StrCat("Field ", field.full_name(),
                        " has a closed enum type with implicit presence."));
     }
+    if (source_features.GetExtension(::pb::cpp).utf8_validation() ==
+        pb::CppFeatures::UTF8_VALIDATION_UNKNOWN) {
+      status = absl::FailedPreconditionError(absl::StrCat(
+          "Field ", field.full_name(),
+          " has an unknown value for the utf8_validation feature. ",
+          source_features.DebugString(), "\nRawFeatures: ", raw_features));
+    }
+
+    if (field.containing_type() == nullptr ||
+        !field.containing_type()->options().map_entry()) {
+      // Skip validation of explicit features on generated map fields.  These
+      // will be blindly propagated from the original map field, and may violate
+      // a lot of these conditions.  Note: we do still validate the
+      // user-specified map field.
+      if (raw_features.GetExtension(::pb::cpp).has_legacy_closed_enum() &&
+          field.cpp_type() != FieldDescriptor::CPPTYPE_ENUM) {
+        status = absl::FailedPreconditionError(
+            absl::StrCat("Field ", field.full_name(),
+                         " specifies the legacy_closed_enum feature but has "
+                         "non-enum type."));
+      }
+      if (field.type() != FieldDescriptor::TYPE_STRING &&
+          !IsStringMapType(field) &&
+          raw_features.GetExtension(::pb::cpp).has_utf8_validation()) {
+        status = absl::FailedPreconditionError(
+            absl::StrCat("Field ", field.full_name(),
+                         " specifies the utf8_validation feature but is not of "
+                         "string type."));
+      }
+    }
+
 #ifdef PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE
     if (field.options().has_ctype()) {
       if (field.cpp_type() != FieldDescriptor::CPPTYPE_STRING) {

src/google/protobuf/compiler/cpp/generator_unittest.cc

@@ -87,7 +87,6 @@ TEST_F(CppGeneratorTest, BasicError) {
       "foo.proto:4:7: Expected \"required\", \"optional\", or \"repeated\"");
 }
 
-
 TEST_F(CppGeneratorTest, LegacyClosedEnumOnNonEnumField) {
   CreateTempFile("foo.proto",
                  R"schema(
@@ -150,8 +149,7 @@ TEST_F(CppGeneratorTest, LegacyClosedEnumInherited) {
 }
 
 TEST_F(CppGeneratorTest, LegacyClosedEnumImplicit) {
-  CreateTempFile("foo.proto",
+  CreateTempFile("foo.proto", R"schema(
-                 R"schema(
     edition = "2023";
     import "google/protobuf/cpp_features.proto";
     option features.(pb.cpp).legacy_closed_enum = true;
@@ -162,7 +160,8 @@ TEST_F(CppGeneratorTest, LegacyClosedEnumImplicit) {
     message Foo {
       TestEnum bar = 1 [features.field_presence = IMPLICIT];
       int32 baz = 2;
-    })schema");
+    }
+  )schema");
 
   RunProtoc(
       "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir "
@@ -172,6 +171,88 @@ TEST_F(CppGeneratorTest, LegacyClosedEnumImplicit) {
       "Field Foo.bar has a closed enum type with implicit presence.");
 }
 
+TEST_F(CppGeneratorTest, Utf8ValidationMap) {
+  CreateTempFile("foo.proto", R"schema(
+    edition = "2023";
+    import "google/protobuf/cpp_features.proto";
+
+    message Foo {
+      map<string, string> map_field = 1 [
+        features.(pb.cpp).utf8_validation = NONE
+      ];
+      map<int32, string> map_field_value = 2 [
+        features.(pb.cpp).utf8_validation = VERIFY_PARSE
+      ];
+      map<string, int32> map_field_key = 3 [
+        features.(pb.cpp).utf8_validation = VERIFY_DLOG
+      ];
+    }
+  )schema");
+
+  RunProtoc(
+      "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir "
+      "--experimental_editions foo.proto");
+
+  ExpectNoErrors();
+}
+
+TEST_F(CppGeneratorTest, Utf8ValidationNonString) {
+  CreateTempFile("foo.proto", R"schema(
+    edition = "2023";
+    import "google/protobuf/cpp_features.proto";
+
+    message Foo {
+      int64 bar = 1 [
+        features.(pb.cpp).utf8_validation = NONE
+      ];
+    }
+  )schema");
+
+  RunProtoc(
+      "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir "
+      "--experimental_editions foo.proto");
+
+  ExpectErrorSubstring("Field Foo.bar specifies the utf8_validation feature");
+}
+
+TEST_F(CppGeneratorTest, Utf8ValidationNonStringMap) {
+  CreateTempFile("foo.proto", R"schema(
+    edition = "2023";
+    import "google/protobuf/cpp_features.proto";
+
+    message Foo {
+      map<int64, int64> bar = 1 [
+        features.(pb.cpp).utf8_validation = VERIFY_PARSE
+      ];
+    }
+  )schema");
+
+  RunProtoc(
+      "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir "
+      "--experimental_editions foo.proto");
+
+  ExpectErrorSubstring("Field Foo.bar specifies the utf8_validation feature");
+}
+
+TEST_F(CppGeneratorTest, Utf8ValidationUnknownValue) {
+  CreateTempFile("foo.proto", R"schema(
+    edition = "2023";
+    import "google/protobuf/cpp_features.proto";
+
+    message Foo {
+      string bar = 1 [
+        features.(pb.cpp).utf8_validation = UTF8_VALIDATION_UNKNOWN
+      ];
+    }
+  )schema");
+
+  RunProtoc(
+      "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir "
+      "--experimental_editions foo.proto");
+
+  ExpectErrorSubstring(
+      "Field Foo.bar has an unknown value for the utf8_validation feature.");
+}
 #ifdef PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE
 TEST_F(CppGeneratorTest, CtypeOnNoneStringFieldTest) {
   CreateTempFile("foo.proto",

src/google/protobuf/compiler/parser_unittest.cc

@@ -4243,7 +4243,7 @@ TEST_F(ParseEditionsTest, InvalidMerge) {
           string foo = 1 [
             default = "hello",
             features.field_presence = FIELD_PRESENCE_UNKNOWN,
-            features.string_field_validation = STRING_FIELD_VALIDATION_UNKNOWN
+            features.enum_type = ENUM_TYPE_UNKNOWN
           ];
         })schema",
       "5:17: Feature field google.protobuf.FeatureSet.field_presence must resolve to a "

src/google/protobuf/descriptor.cc

@@ -1117,10 +1117,11 @@ FeatureSet* CreateProto2DefaultFeatures() {
   features->set_field_presence(FeatureSet::EXPLICIT);
   features->set_enum_type(FeatureSet::CLOSED);
   features->set_repeated_field_encoding(FeatureSet::EXPANDED);
-  features->set_string_field_validation(FeatureSet::HINT);
   features->set_message_encoding(FeatureSet::LENGTH_PREFIXED);
   features->set_json_format(FeatureSet::LEGACY_BEST_EFFORT);
   features->MutableExtension(pb::cpp)->set_legacy_closed_enum(true);
+  features->MutableExtension(pb::cpp)->set_utf8_validation(
+      pb::CppFeatures::VERIFY_DLOG);
 
   return features;
 }
@@ -1145,9 +1146,11 @@ const FeatureSet& GetProto3Features() {
     features->set_field_presence(FeatureSet::IMPLICIT);
     features->set_enum_type(FeatureSet::OPEN);
     features->set_repeated_field_encoding(FeatureSet::PACKED);
-    features->set_string_field_validation(FeatureSet::MANDATORY);
     features->set_message_encoding(FeatureSet::LENGTH_PREFIXED);
     features->set_json_format(FeatureSet::ALLOW);
+    features->MutableExtension(pb::cpp)->set_legacy_closed_enum(false);
+    features->MutableExtension(pb::cpp)->set_utf8_validation(
+        pb::CppFeatures::VERIFY_PARSE);
     return features;
   }();
   return *kProto3Features;
@@ -3817,7 +3820,8 @@ bool FieldDescriptor::is_packed() const {
 
 static bool IsStrictUtf8(const FieldDescriptor* field) {
   return internal::InternalFeatureHelper::GetFeatures(*field)
-             .string_field_validation() == FeatureSet::MANDATORY;
+             .GetExtension(pb::cpp)
+             .utf8_validation() == pb::CppFeatures::VERIFY_PARSE;
 }
 
 bool FieldDescriptor::requires_utf8_validation() const {
@@ -7838,17 +7842,6 @@ void DescriptorBuilder::ValidateOptions(const FieldDescriptor* field,
 
 }
 
-static bool IsStringMapType(const FieldDescriptor* field) {
-  if (!field->is_map()) return false;
-  for (int i = 0; i < field->message_type()->field_count(); ++i) {
-    if (field->message_type()->field(i)->type() ==
-        FieldDescriptor::TYPE_STRING) {
-      return true;
-    }
-  }
-  return false;
-}
-
 void DescriptorBuilder::ValidateFieldFeatures(
     const FieldDescriptor* field, const FieldDescriptorProto& proto) {
   // Rely on our legacy validation for proto2/proto3 files.
@@ -7895,12 +7888,6 @@ void DescriptorBuilder::ValidateFieldFeatures(
         field->full_name(), proto, DescriptorPool::ErrorCollector::NAME,
         "Only singular scalar fields can specify required field presence.");
   }
-  if (field->type() != FieldDescriptor::TYPE_STRING &&
-      !IsStringMapType(field) &&
-      field->proto_features_->has_string_field_validation()) {
-    AddError(field->full_name(), proto, DescriptorPool::ErrorCollector::NAME,
-             "Only string fields can specify `string_field_validation`.");
-  }
   if (!field->is_repeated() &&
       field->proto_features_->has_repeated_field_encoding()) {
     AddError(field->full_name(), proto, DescriptorPool::ErrorCollector::NAME,

src/google/protobuf/descriptor_unittest.cc

@@ -63,8 +63,11 @@
 #include "absl/strings/str_format.h"
 #include "absl/strings/string_view.h"
 #include "absl/strings/substitute.h"
+#include "google/protobuf/compiler/parser.h"
 #include "google/protobuf/cpp_features.pb.h"
 #include "google/protobuf/descriptor_legacy.h"
+#include "google/protobuf/io/tokenizer.h"
+#include "google/protobuf/io/zero_copy_stream_impl_lite.h"
 #include "google/protobuf/test_textproto.h"
 #include "google/protobuf/unittest.pb.h"
 #include "google/protobuf/unittest_custom_options.pb.h"
@@ -7254,26 +7257,32 @@ TEST_F(FeaturesTest, Proto2Features) {
                 field_presence: EXPLICIT
                 enum_type: CLOSED
                 repeated_field_encoding: EXPANDED
-                string_field_validation: HINT
                 message_encoding: LENGTH_PREFIXED
                 json_format: LEGACY_BEST_EFFORT
-                [pb.cpp] { legacy_closed_enum: true })pb"));
+                [pb.cpp] {
+                  legacy_closed_enum: true
+                  utf8_validation: VERIFY_DLOG
+                })pb"));
   EXPECT_THAT(GetFeatures(field), EqualsProto(R"pb(
                 field_presence: EXPLICIT
                 enum_type: CLOSED
                 repeated_field_encoding: EXPANDED
-                string_field_validation: HINT
                 message_encoding: LENGTH_PREFIXED
                 json_format: LEGACY_BEST_EFFORT
-                [pb.cpp] { legacy_closed_enum: true })pb"));
+                [pb.cpp] {
+                  legacy_closed_enum: true
+                  utf8_validation: VERIFY_DLOG
+                })pb"));
   EXPECT_THAT(GetFeatures(group), EqualsProto(R"pb(
                 field_presence: EXPLICIT
                 enum_type: CLOSED
                 repeated_field_encoding: EXPANDED
-                string_field_validation: HINT
                 message_encoding: DELIMITED
                 json_format: LEGACY_BEST_EFFORT
-                [pb.cpp] { legacy_closed_enum: true })pb"));
+                [pb.cpp] {
+                  legacy_closed_enum: true
+                  utf8_validation: VERIFY_DLOG
+                })pb"));
   EXPECT_TRUE(field->has_presence());
   EXPECT_FALSE(field->requires_utf8_validation());
   EXPECT_FALSE(field->is_packed());
@@ -7324,16 +7333,22 @@ TEST_F(FeaturesTest, Proto3Features) {
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
-                json_format: ALLOW)pb"));
+                json_format: ALLOW
+                [pb.cpp] {
+                  legacy_closed_enum: false
+                  utf8_validation: VERIFY_PARSE
+                })pb"));
   EXPECT_THAT(GetFeatures(field), EqualsProto(R"pb(
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
-                json_format: ALLOW)pb"));
+                json_format: ALLOW
+                [pb.cpp] {
+                  legacy_closed_enum: false
+                  utf8_validation: VERIFY_PARSE
+                })pb"));
   EXPECT_FALSE(field->has_presence());
   EXPECT_FALSE(field->requires_utf8_validation());
   EXPECT_FALSE(field->is_packed());
@@ -7463,7 +7478,6 @@ TEST_F(FeaturesTest, Edition2023Defaults) {
         field_presence: EXPLICIT
         enum_type: OPEN
         repeated_field_encoding: PACKED
-        string_field_validation: MANDATORY
         message_encoding: LENGTH_PREFIXED
         json_format: ALLOW
         [pb.cpp] { legacy_closed_enum: false utf8_validation: VERIFY_PARSE }
@@ -7491,7 +7505,6 @@ TEST_F(FeaturesTest, ClearsOptions) {
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -7754,7 +7767,6 @@ TEST_F(FeaturesTest, NoOptions) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -7787,7 +7799,6 @@ TEST_F(FeaturesTest, FileFeatures) {
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -7865,7 +7876,6 @@ TEST_F(FeaturesTest, MessageFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -7973,7 +7983,6 @@ TEST_F(FeaturesTest, FieldFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8211,52 +8220,6 @@ TEST_F(FeaturesTest, MapFieldFeaturesOverride) {
   validate(value);
 }
 
-TEST_F(FeaturesTest, MapFieldFeaturesStringValidation) {
-  constexpr absl::string_view kProtoFile = R"schema(
-    edition = "2023";
-
-    message Foo {
-      map<string, string> map_field = 1 [
-        features.string_field_validation = HINT
-      ];
-      map<int32, string> map_field_value = 2 [
-        features.string_field_validation = HINT
-      ];
-      map<string, int32> map_field_key = 3 [
-        features.string_field_validation = HINT
-      ];
-    }
-  )schema";
-  io::ArrayInputStream input_stream(kProtoFile.data(), kProtoFile.size());
-  SimpleErrorCollector error_collector;
-  io::Tokenizer tokenizer(&input_stream, &error_collector);
-  compiler::Parser parser;
-  parser.RecordErrorsTo(&error_collector);
-  FileDescriptorProto proto;
-  ASSERT_TRUE(parser.Parse(&tokenizer, &proto))
-      << error_collector.last_error() << "\n"
-      << kProtoFile;
-  ASSERT_EQ("", error_collector.last_error());
-  proto.set_name("foo.proto");
-
-  BuildDescriptorMessagesInTestPool();
-  const FileDescriptor* file = pool_.BuildFile(proto);
-  ASSERT_THAT(file, NotNull());
-
-  auto validate_map_field = [](const FieldDescriptor* field) {
-    const FieldDescriptor* key = field->message_type()->field(0);
-    const FieldDescriptor* value = field->message_type()->field(1);
-
-    EXPECT_FALSE(field->requires_utf8_validation()) << field->DebugString();
-    EXPECT_FALSE(key->requires_utf8_validation()) << field->DebugString();
-    EXPECT_FALSE(value->requires_utf8_validation()) << field->DebugString();
-  };
-
-  validate_map_field(file->message_type(0)->field(0));
-  validate_map_field(file->message_type(0)->field(1));
-  validate_map_field(file->message_type(0)->field(2));
-}
-
 TEST_F(FeaturesTest, RootExtensionFeaturesOverride) {
   BuildDescriptorMessagesInTestPool();
   BuildFileInTestPool(pb::TestFeatures::descriptor()->file());
@@ -8364,7 +8327,6 @@ TEST_F(FeaturesTest, EnumFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8474,7 +8436,6 @@ TEST_F(FeaturesTest, EnumValueFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8569,7 +8530,6 @@ TEST_F(FeaturesTest, OneofFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8671,7 +8631,6 @@ TEST_F(FeaturesTest, ExtensionRangeFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8758,7 +8717,6 @@ TEST_F(FeaturesTest, ServiceFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8827,7 +8785,6 @@ TEST_F(FeaturesTest, MethodFeaturesDefault) {
                 field_presence: EXPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -8908,9 +8865,11 @@ TEST_F(FeaturesTest, MethodFeaturesOverride) {
 
 TEST_F(FeaturesTest, FieldFeatureHelpers) {
   BuildDescriptorMessagesInTestPool();
+  BuildFileInTestPool(pb::CppFeatures::GetDescriptor()->file());
   const FileDescriptor* file = BuildFile(R"pb(
     name: "foo.proto"
     syntax: "editions"
+    dependency: "google/protobuf/cpp_features.proto"
     edition: "2023"
     message_type {
       name: "Foo"
@@ -8950,14 +8909,22 @@ TEST_F(FeaturesTest, FieldFeatureHelpers) {
         number: 7
         label: LABEL_REPEATED
         type: TYPE_STRING
-        options { features { string_field_validation: HINT } }
+        options {
+          features {
+            [pb.cpp] { utf8_validation: VERIFY_DLOG }
+          }
+        }
       }
       field {
         name: "utf8_none_field"
         number: 8
         label: LABEL_REPEATED
         type: TYPE_STRING
-        options { features { string_field_validation: NONE } }
+        options {
+          features {
+            [pb.cpp] { utf8_validation: NONE }
+          }
+        }
       }
     }
   )pb");
@@ -9243,6 +9210,35 @@ TEST_F(FeaturesTest, InvalidFieldRepeatedImplicit) {
       "implicit field presence.\n");
 }
 
+TEST_F(FeaturesTest, InvalidFieldMapImplicit) {
+  constexpr absl::string_view kProtoFile = R"schema(
+    edition = "2023";
+
+    message Foo {
+      map<string, Foo> bar = 1 [
+        features.field_presence = IMPLICIT
+      ];
+    }
+  )schema";
+  io::ArrayInputStream input_stream(kProtoFile.data(), kProtoFile.size());
+  SimpleErrorCollector error_collector;
+  io::Tokenizer tokenizer(&input_stream, &error_collector);
+  compiler::Parser parser;
+  parser.RecordErrorsTo(&error_collector);
+  FileDescriptorProto proto;
+  ASSERT_TRUE(parser.Parse(&tokenizer, &proto))
+      << error_collector.last_error() << "\n"
+      << kProtoFile;
+  ASSERT_EQ("", error_collector.last_error());
+  proto.set_name("foo.proto");
+
+  BuildDescriptorMessagesInTestPool();
+  BuildFileWithErrors(
+      proto.DebugString(),
+      "foo.proto: Foo.bar: NAME: Only singular scalar fields can specify "
+      "implicit field presence.\n");
+}
+
 TEST_F(FeaturesTest, InvalidFieldOneofImplicit) {
   BuildDescriptorMessagesInTestPool();
   BuildFileWithErrors(
@@ -9313,95 +9309,6 @@ TEST_F(FeaturesTest, InvalidFieldOneofRequired) {
       "required field presence.\n");
 }
 
-TEST_F(FeaturesTest, InvalidFieldNonStringWithStringValidation) {
-  BuildDescriptorMessagesInTestPool();
-  BuildFileWithErrors(
-      R"pb(
-        name: "foo.proto"
-        syntax: "editions"
-        edition: "2023"
-        message_type {
-          name: "Foo"
-          field {
-            name: "bar"
-            number: 1
-            label: LABEL_OPTIONAL
-            type: TYPE_INT64
-            options { features { string_field_validation: MANDATORY } }
-          }
-        }
-      )pb",
-      "foo.proto: Foo.bar: NAME: Only string fields can specify "
-      "`string_field_validation`.\n");
-}
-
-TEST_F(FeaturesTest, InvalidFieldNonStringMapWithStringValidation) {
-  BuildDescriptorMessagesInTestPool();
-  BuildFileWithErrors(
-      R"pb(
-        name: "foo.proto"
-        syntax: "editions"
-        edition: "2023"
-        message_type {
-          name: "Foo"
-          nested_type {
-            name: "MapFieldEntry"
-            field {
-              name: "key"
-              number: 1
-              label: LABEL_OPTIONAL
-              type: TYPE_INT32
-              options {
-                uninterpreted_option {
-                  name { name_part: "features" is_extension: false }
-                  name {
-                    name_part: "string_field_validation"
-                    is_extension: false
-                  }
-                  identifier_value: "HINT"
-                }
-              }
-            }
-            field {
-              name: "value"
-              number: 2
-              label: LABEL_OPTIONAL
-              type: TYPE_INT32
-              options {
-                uninterpreted_option {
-                  name { name_part: "features" is_extension: false }
-                  name {
-                    name_part: "string_field_validation"
-                    is_extension: false
-                  }
-                  identifier_value: "HINT"
-                }
-              }
-            }
-            options { map_entry: true }
-          }
-          field {
-            name: "map_field"
-            number: 1
-            label: LABEL_REPEATED
-            type_name: "MapFieldEntry"
-            options {
-              uninterpreted_option {
-                name { name_part: "features" is_extension: false }
-                name {
-                  name_part: "string_field_validation"
-                  is_extension: false
-                }
-                identifier_value: "HINT"
-              }
-            }
-          }
-        }
-      )pb",
-      "foo.proto: Foo.map_field: NAME: Only string fields can specify "
-      "`string_field_validation`.\n");
-}
-
 TEST_F(FeaturesTest, InvalidFieldNonRepeatedWithRepeatedEncoding) {
   BuildDescriptorMessagesInTestPool();
   BuildFileWithErrors(
@@ -9519,7 +9426,6 @@ TEST_F(FeaturesTest, UninterpretedOptions) {
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -9647,7 +9553,6 @@ TEST_F(FeaturesTest, RawFeatures) {
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {
@@ -9674,7 +9579,6 @@ TEST_F(FeaturesTest, RawFeaturesConflict) {
                 field_presence: IMPLICIT
                 enum_type: OPEN
                 repeated_field_encoding: PACKED
-                string_field_validation: MANDATORY
                 message_encoding: LENGTH_PREFIXED
                 json_format: ALLOW
                 [pb.cpp] {

src/google/protobuf/editions/BUILD

@@ -2,6 +2,7 @@ load("@rules_cc//cc:defs.bzl", "cc_proto_library")
 
 proto_library(
     name = "test_messages_proto2_proto",
+    testonly = True,
     srcs = ["golden/test_messages_proto2.proto"],
     strip_import_prefix = "/src",
     deps = ["//src/google/protobuf:cpp_features_proto"],
@@ -9,11 +10,13 @@ proto_library(
 
 cc_proto_library(
     name = "test_messages_proto2_cc_proto",
+    testonly = True,
     deps = [":test_messages_proto2_proto"],
 )
 
 proto_library(
     name = "test_messages_proto3_proto",
+    testonly = True,
     srcs = ["golden/test_messages_proto3.proto"],
     strip_import_prefix = "/src",
     deps = [
@@ -29,25 +32,28 @@ proto_library(
 
 cc_proto_library(
     name = "test_messages_proto3_cc_proto",
+    testonly = True,
     deps = [":test_messages_proto3_proto"],
 )
 
 proto_library(
-    name = "editions_default_features_proto",
+    name = "test_editions_default_features_proto",
-    srcs = ["proto/editions_default_features.proto"],
+    testonly = True,
+    srcs = ["proto/test_editions_default_features.proto"],
     strip_import_prefix = "/src",
 )
 
 cc_proto_library(
-    name = "editions_default_features_cc_proto",
+    name = "test_editions_default_features_cc_proto",
-    deps = [":editions_default_features_proto"],
+    testonly = True,
+    deps = [":test_editions_default_features_proto"],
 )
 
 cc_test(
     name = "generated_files_test",
     srcs = ["generated_files_test.cc"],
     deps = [
-        ":editions_default_features_cc_proto",
+        ":test_editions_default_features_cc_proto",
         ":test_messages_proto2_cc_proto",
         ":test_messages_proto3_cc_proto",
         "//src/google/protobuf",

src/google/protobuf/editions/generated_files_test.cc

@@ -33,7 +33,7 @@
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/editions/golden/test_messages_proto2.pb.h"
 #include "google/protobuf/editions/golden/test_messages_proto3.pb.h"
-#include "google/protobuf/editions/proto/editions_default_features.pb.h"
+#include "google/protobuf/editions/proto/test_editions_default_features.pb.h"
 #include "google/protobuf/test_textproto.h"
 
 // These tests provide some basic minimal coverage that protos work as expected.
@@ -166,7 +166,6 @@ TEST(Generated, EditionDefaults2023InternalFeatures) {
         field_presence: EXPLICIT
         enum_type: OPEN
         repeated_field_encoding: PACKED
-        string_field_validation: MANDATORY
         message_encoding: LENGTH_PREFIXED
         json_format: ALLOW
         [pb.cpp] { legacy_closed_enum: false utf8_validation: VERIFY_PARSE }

src/google/protobuf/editions/golden/compare_cpp_codegen_failure.txt

@@ -35,6 +35,14 @@
      total_size += ::_pbi::WireFormatLite::Int32SizePlusOne(
 [  FAILED  ] third_party/protobuf/editions/golden/simple_proto3.pb.cc
 [ RUN      ] third_party/protobuf/editions/golden/simple_proto3.pb.h
+@@ @@
+ #include "third_party/protobuf/generated_message_util.h"
+ #include "third_party/protobuf/metadata_lite.h"
+ #include "third_party/protobuf/message_lite.h"
++#include "third_party/protobuf/cpp_features.pb.h"
+ // @@protoc_insertion_point(includes)
+ 
+ // Must be included last.
 @@ @@
    enum : int {
      kInt32FieldFieldNumber = 1,

src/google/protobuf/editions/golden/compare_cpp_codegen_failure.xml

@@ -5,7 +5,7 @@
 <failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.cc&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#include &quot;third_party/protobuf/editions/golden/simple_proto3.pb.h&quot;&#x0A;&#x0A;#include &lt;algorithm&gt;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/extension_set.h&quot;&#x0A;#include &quot;third_party/protobuf/wire_format_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/io/zero_copy_stream_impl_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_impl.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;, with the difference:&#x0A;@@ @@&#x0A;     &amp;_SimpleProto3_default_instance_._instance,&#x0A;     ::_pbi::TcParser::GenericFallbackLite,  // fallback&#x0A;   }, {{&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1 [features = {&#x0A;     {::_pbi::TcParser::FastV32S1,&#x0A;      {8, 0, 0, PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_)}},&#x0A;   }}, {{&#x0A;     65535, 65535&#x0A;   }}, {{&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1 [features = {&#x0A;     {PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_), _Internal::kHasBitsOffset + 0, 0,&#x0A;     (0 | ::_fl::kFcOptional | ::_fl::kInt32)},&#x0A;   }},&#x0A;@@ @@&#x0A;   (void)cached_has_bits;&#x0A; &#x0A;   cached_has_bits = _impl_._has_bits_[0];&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1 [features = {&#x0A;   if (cached_has_bits &amp; 0x00000001u) {&#x0A;     target = ::proto2::internal::WireFormatLite::&#x0A;         WriteInt32ToArrayWithField&lt;1&gt;(&#x0A;@@ @@&#x0A;   // Prevent compiler warnings about cached_has_bits being unused&#x0A;   (void) cached_has_bits;&#x0A; &#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1 [features = {&#x0A;   cached_has_bits = _impl_._has_bits_[0];&#x0A;   if (cached_has_bits &amp; 0x00000001u) {&#x0A;     total_size += ::_pbi::WireFormatLite::Int32SizePlusOne(" type=""></failure>
 </testcase>
 <testcase name="third_party/protobuf/editions/golden/simple_proto3.pb.h" status="run" result="completed" classname="DiffTest">
-<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.h&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#ifndef GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;#define GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;&#x0A;#include &lt;limits&gt;&#x0A;#include &lt;string&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;&#x0A;#include &quot;third_party/protobuf/wire_format_verify.h&quot;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/arena.h&quot;&#x0A;#include &quot;third_party/protobuf/arenastring.h&quot;&#x0A;#include &quot;third_party/protobuf/inlined_string_field.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_decl.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/metadata_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/message_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;&#x0A;#endif  // GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;, with the difference:&#x0A;@@ @@&#x0A;   enum : int {&#x0A;     kInt32FieldFieldNumber = 1,&#x0A;   };&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1 [features = {&#x0A;   bool has_int32_field() const;&#x0A;   void clear_int32_field() ;&#x0A;   ::int32_t int32_field() const;&#x0A;@@ @@&#x0A; &#x0A; // SimpleProto3&#x0A; &#x0A;-// optional int32 int32_field = 1;&#x0A;+// int32 int32_field = 1 [features = {&#x0A; inline bool SimpleProto3::has_int32_field() const {&#x0A;   bool value = (_impl_._has_bits_[0] &amp; 0x00000001u) != 0;&#x0A;   return value;" type=""></failure>
+<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.h&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#ifndef GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;#define GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;&#x0A;#include &lt;limits&gt;&#x0A;#include &lt;string&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;&#x0A;#include &quot;third_party/protobuf/wire_format_verify.h&quot;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/arena.h&quot;&#x0A;#include &quot;third_party/protobuf/arenastring.h&quot;&#x0A;#include &quot;third_party/protobuf/inlined_string_field.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_decl.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/metadata_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/message_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;&#x0A;#endif  // GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;, with the difference:&#x0A;@@ @@&#x0A; #include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A; #include &quot;third_party/protobuf/metadata_lite.h&quot;&#x0A; #include &quot;third_party/protobuf/message_lite.h&quot;&#x0A;+#include &quot;third_party/protobuf/cpp_features.pb.h&quot;&#x0A; // @@protoc_insertion_point(includes)&#x0A; &#x0A; // Must be included last.&#x0A;@@ @@&#x0A;   enum : int {&#x0A;     kInt32FieldFieldNumber = 1,&#x0A;   };&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1 [features = {&#x0A;   bool has_int32_field() const;&#x0A;   void clear_int32_field() ;&#x0A;   ::int32_t int32_field() const;&#x0A;@@ @@&#x0A; &#x0A; // SimpleProto3&#x0A; &#x0A;-// optional int32 int32_field = 1;&#x0A;+// int32 int32_field = 1 [features = {&#x0A; inline bool SimpleProto3::has_int32_field() const {&#x0A;   bool value = (_impl_._has_bits_[0] &amp; 0x00000001u) != 0;&#x0A;   return value;" type=""></failure>
 </testcase>
 <testcase name="third_party/protobuf/editions/golden/simple_proto3.proto.static_reflection.h" status="run" result="completed" classname="DiffTest">
 </testcase>

src/google/protobuf/editions/golden/editions_transform_proto2.proto

@@ -32,9 +32,9 @@ edition = "2023";
 import "google/protobuf/cpp_features.proto";
 option features.enum_type = CLOSED;
 option features.repeated_field_encoding = EXPANDED;
-option features.string_field_validation = HINT;
 option features.json_format = LEGACY_BEST_EFFORT;
 option features.(pb.cpp).legacy_closed_enum = true;
+option features.(pb.cpp).utf8_validation = VERIFY_DLOG;
 
 // This file contains various edge cases we've collected from migrating real
 // protos in order to lock down the transformations.

src/google/protobuf/editions/golden/editions_transform_proto2_lite.proto

@@ -32,9 +32,9 @@ edition = "2023";
 import "google/protobuf/cpp_features.proto";
 option features.enum_type = CLOSED;
 option features.repeated_field_encoding = EXPANDED;
-option features.string_field_validation = HINT;
 option features.json_format = LEGACY_BEST_EFFORT;
 option features.(pb.cpp).legacy_closed_enum = true;
+option features.(pb.cpp).utf8_validation = VERIFY_DLOG;
 
 package protobuf_editions_test;
 

src/google/protobuf/editions/golden/editions_transform_proto2_utf8_disabled.proto

@@ -32,19 +32,19 @@ edition = "2023";
 import "google/protobuf/cpp_features.proto";
 option features.enum_type = CLOSED;
 option features.repeated_field_encoding = EXPANDED;
-option features.string_field_validation = HINT;
 option features.json_format = LEGACY_BEST_EFFORT;
 option features.(pb.cpp).legacy_closed_enum = true;
+option features.(pb.cpp).utf8_validation = VERIFY_DLOG;
 
 package protobuf_editions_test;
 
 
 message TestMessageUtf8Disabled {
-  string string_field = 1 [features.string_field_validation = NONE];
+  string string_field = 1 [features.(pb.cpp).utf8_validation = NONE];
-  string string_field_utf = 2 [features.string_field_validation = NONE];
+  string string_field_utf = 2 [features.(pb.cpp).utf8_validation = NONE];
-  string string_field_noutf = 3 [features.string_field_validation = NONE];
+  string string_field_noutf = 3 [features.(pb.cpp).utf8_validation = NONE];
 
-  map<string, string> string_map_field = 4 [features.string_field_validation = NONE];
+  map<string, string> string_map_field = 4 [features.(pb.cpp).utf8_validation = NONE];
 
   int32 int_field = 5;
 }

src/google/protobuf/editions/golden/editions_transform_proto3.proto

@@ -29,18 +29,20 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 edition = "2023";
+import "google/protobuf/cpp_features.proto";
 option features.field_presence = IMPLICIT;
+option features.(pb.cpp).utf8_validation = VERIFY_PARSE;
 
 package protobuf_editions_test;
 
 message TestMessageProto3 {
   string string_field = 1;
   string string_field_utf = 2;
-  string string_field_noutf = 3 [features.string_field_validation = HINT];
+  string string_field_noutf = 3 [features.(pb.cpp).utf8_validation = VERIFY_DLOG];
 
   map<string, string> string_map_field = 4;
   map<string, string> string_map_field_utf = 5;
-  map<string, string> string_map_field_noutf = 6 [features.string_field_validation = HINT];
+  map<string, string> string_map_field_noutf = 6 [features.(pb.cpp).utf8_validation = VERIFY_DLOG];
 
   repeated int32 int_field = 7;
   repeated int32 int_field_packed = 8;

src/google/protobuf/editions/golden/editions_transform_proto3_utf8_disabled.proto

@@ -29,17 +29,19 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 edition = "2023";
+import "google/protobuf/cpp_features.proto";
 option features.field_presence = IMPLICIT;
+option features.(pb.cpp).utf8_validation = VERIFY_PARSE;
 
 package protobuf_editions_test;
 
 
 message TestMessageProto3 {
-  string string_field = 1 [features.string_field_validation = NONE];
+  string string_field = 1 [features.(pb.cpp).utf8_validation = NONE];
-  string string_field_utf = 2 [features.string_field_validation = NONE];
+  string string_field_utf = 2 [features.(pb.cpp).utf8_validation = NONE];
-  string string_field_noutf = 3 [features.string_field_validation = NONE];
+  string string_field_noutf = 3 [features.(pb.cpp).utf8_validation = NONE];
 
-  map<string, string> string_map_field = 4 [features.string_field_validation = NONE];
+  map<string, string> string_map_field = 4 [features.(pb.cpp).utf8_validation = NONE];
 
   repeated int32 int_field = 7;
 }

src/google/protobuf/editions/golden/test_messages_proto2.proto

@@ -39,9 +39,9 @@ edition = "2023";
 import "google/protobuf/cpp_features.proto";
 option features.enum_type = CLOSED;
 option features.repeated_field_encoding = EXPANDED;
-option features.string_field_validation = HINT;
 option features.json_format = LEGACY_BEST_EFFORT;
 option features.(pb.cpp).legacy_closed_enum = true;
+option features.(pb.cpp).utf8_validation = VERIFY_DLOG;
 
 package protobuf_test_messages.proto2;
 

src/google/protobuf/editions/golden/test_messages_proto3.proto

@@ -36,7 +36,9 @@
 //
 
 edition = "2023";
+import "google/protobuf/cpp_features.proto";
 option features.field_presence = IMPLICIT;
+option features.(pb.cpp).utf8_validation = VERIFY_PARSE;
 
 package protobuf_test_messages.proto3;
 

src/google/protobuf/editions/transform.awk

@@ -78,15 +78,15 @@ function transform_field(field)
       options[++num_options] = "features.field_presence = LEGACY_REQUIRED"
     }
     if (disable_utf8 && match(field_def, /^\s*(string|repeated\s*string|map<string,\s*string>)/)) {
-      options[++num_options] = "features.string_field_validation = NONE"
+      options[++num_options] = "features.(pb.cpp).utf8_validation = NONE"
     }
   }
 
   if(syntax == 3) {
     if (disable_utf8 && match(field_def, /^\s*(string|repeated\s*string|map<string,\s*string>)/)) {
-      options[++num_options] = "features.string_field_validation = NONE"
+      options[++num_options] = "features.(pb.cpp).utf8_validation = NONE"
     } else {
-      sub(/\<enforce_utf8 = false\>/, "features.string_field_validation = HINT", existing_options)
+      sub(/\<enforce_utf8 = false\>/, "features.(pb.cpp).utf8_validation = VERIFY_DLOG", existing_options)
     }
     sub(/\<packed = false\>/, "features.repeated_field_encoding = EXPANDED", existing_options)
     existing_options = strip_option("packed = true", existing_options)
@@ -121,16 +121,18 @@ function transform_field(field)
   print "import \"third_party/protobuf/cpp_features.proto\";"
   print "option features.enum_type = CLOSED;"
   print "option features.repeated_field_encoding = EXPANDED;"
-  print "option features.string_field_validation = HINT;"
   print "option features.json_format = LEGACY_BEST_EFFORT;"
   print "option features.(pb.cpp).legacy_closed_enum = true;"
+  print "option features.(pb.cpp).utf8_validation = VERIFY_DLOG;"
   syntax = 2
   next
 }
 
 /syntax = "proto3"/ {
   print "edition = \"2023\";"
+  print "import \"third_party/protobuf/cpp_features.proto\";"
   print "option features.field_presence = IMPLICIT;"
+  print "option features.(pb.cpp).utf8_validation = VERIFY_PARSE;"
   syntax = 3
   next
 }

src/google/protobuf/feature_resolver.cc

@@ -74,7 +74,8 @@ absl::Status Error(Args... args) {
 bool IsNonFeatureField(const FieldDescriptor& field) {
   return field.containing_type() &&
          field.containing_type()->full_name() == "google.protobuf.FeatureSet" &&
-         field.name() == "raw_features";
+         (field.name() == "raw_features" ||
+          field.name() == "string_field_validation");
 }
 
 bool EditionsLessThan(absl::string_view a, absl::string_view b) {
@@ -197,6 +198,7 @@ absl::Status ValidateMergedFeatures(const Message& msg) {
   const Reflection& reflection = *msg.GetReflection();
   for (int i = 0; i < descriptor.field_count(); ++i) {
     const FieldDescriptor& field = *descriptor.field(i);
+    if (IsNonFeatureField(field)) continue;
     // Validate enum features.
     if (field.enum_type() != nullptr) {
       ABSL_DCHECK(reflection.HasField(msg, &field));

src/google/protobuf/feature_resolver_test.cc

@@ -144,7 +144,6 @@ TEST(FeatureResolverTest, DefaultsCore2023) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::EXPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::PACKED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::MANDATORY);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
   EXPECT_FALSE(merged->HasExtension(pb::test));
 }
@@ -156,7 +155,6 @@ TEST(FeatureResolverTest, DefaultsTest2023) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::EXPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::PACKED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::MANDATORY);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
 
   const pb::TestFeatures& ext = merged->GetExtension(pb::test);
@@ -185,7 +183,6 @@ TEST(FeatureResolverTest, DefaultsTestMessageExtension) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::EXPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::PACKED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::MANDATORY);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
 
   const pb::TestFeatures& ext = merged->GetExtension(pb::test);
@@ -214,7 +211,6 @@ TEST(FeatureResolverTest, DefaultsTestNestedExtension) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::EXPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::PACKED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::MANDATORY);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
 
   const pb::TestFeatures& ext = merged->GetExtension(pb::test);
@@ -370,7 +366,6 @@ TEST(FeatureResolverTest, MergeFeaturesChildOverrideCore) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::IMPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::EXPANDED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::MANDATORY);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
 }
 
@@ -394,7 +389,6 @@ TEST(FeatureResolverTest, MergeFeaturesChildOverrideComplex) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::IMPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::EXPANDED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::MANDATORY);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
 
   pb::TestFeatures ext = merged->GetExtension(pb::test);
@@ -421,7 +415,6 @@ TEST(FeatureResolverTest, MergeFeaturesParentOverrides) {
     }
   )pb");
   FeatureSet child = ParseTextOrDie(R"pb(
-    string_field_validation: NONE
     repeated_field_encoding: PACKED
     [pb.test] {
       int_field_feature: 9
@@ -434,7 +427,6 @@ TEST(FeatureResolverTest, MergeFeaturesParentOverrides) {
   EXPECT_EQ(merged->field_presence(), FeatureSet::IMPLICIT);
   EXPECT_EQ(merged->enum_type(), FeatureSet::OPEN);
   EXPECT_EQ(merged->repeated_field_encoding(), FeatureSet::PACKED);
-  EXPECT_EQ(merged->string_field_validation(), FeatureSet::NONE);
   EXPECT_EQ(merged->message_encoding(), FeatureSet::LENGTH_PREFIXED);
 
   pb::TestFeatures ext = merged->GetExtension(pb::test);
@@ -490,18 +482,6 @@ TEST(FeatureResolverTest, MergeFeaturesRepeatedFieldEncodingUnknown) {
                   HasSubstr("REPEATED_FIELD_ENCODING_UNKNOWN"))));
 }
 
-TEST(FeatureResolverTest, MergeFeaturesStringFieldValidationUnknown) {
-  absl::StatusOr<FeatureResolver> resolver = SetupFeatureResolver("2023");
-  ASSERT_OK(resolver);
-  FeatureSet child = ParseTextOrDie(R"pb(
-    string_field_validation: STRING_FIELD_VALIDATION_UNKNOWN
-  )pb");
-  EXPECT_THAT(resolver->MergeFeatures(FeatureSet(), child),
-              HasError(AllOf(
-                  HasSubstr("field google.protobuf.FeatureSet.string_field_validation"),
-                  HasSubstr("STRING_FIELD_VALIDATION_UNKNOWN"))));
-}
-
 TEST(FeatureResolverTest, MergeFeaturesMessageEncodingUnknown) {
   absl::StatusOr<FeatureResolver> resolver = SetupFeatureResolver("2023");
   ASSERT_OK(resolver);