Use FieldDescriptor.cpp_string_type() instead of CType directly.

PiperOrigin-RevId: 692198493

src/google/protobuf/compiler/rust/accessors/accessors.cc

@@ -27,14 +27,14 @@ namespace {
 
 std::unique_ptr<AccessorGenerator> AccessorGeneratorFor(
     Context& ctx, const FieldDescriptor& field) {
-  // TODO: We do not support ctype=CORD fields or repeated
-  // ctype=STRING_PIECE fields on cpp kernel yet (upb doesn't care about ctype).
-  auto ctype = field.options().ctype();
-  if (ctx.is_cpp() &&
-      (ctype == FieldOptions::CORD || ctype == FieldOptions::STRING_PIECE) &&
-      field.is_repeated()) {
+  // TODO: We do not support repeated strings on C++ kernel if
+  // they are not string_view or string type.
+  if (ctx.is_cpp() && field.is_repeated() &&
+      field.cpp_type() == FieldDescriptor::CPPTYPE_STRING &&
+      field.cpp_string_type() != FieldDescriptor::CppStringType::kView &&
+      field.cpp_string_type() != FieldDescriptor::CppStringType::kString) {
     return std::make_unique<UnsupportedField>(
-        "fields has an unsupported ctype");
+        "unsupported repeated string type");
   }
 
   if (field.is_map()) {
@@ -57,7 +57,8 @@ std::unique_ptr<AccessorGenerator> AccessorGeneratorFor(
       return std::make_unique<SingularScalar>();
     case RustFieldType::BYTES:
     case RustFieldType::STRING:
-      if (ctype == FieldOptions::CORD) {
+      if (ctx.is_cpp() &&
+          field.cpp_string_type() == FieldDescriptor::CppStringType::kCord) {
         return std::make_unique<SingularCord>();
       }
       return std::make_unique<SingularString>();

src/google/protobuf/compiler/rust/accessors/with_presence.cc

@@ -83,7 +83,12 @@ void WithPresenceAccessorsInMsgImpl(Context& ctx, const FieldDescriptor& field,
        {"opt_getter",
         [&] {
           // Cord fields don't support the _opt getter.
-          if (field.options().ctype() == FieldOptions::CORD) return;
+          if (ctx.is_cpp() &&
+              field.cpp_type() == FieldDescriptor::CPPTYPE_STRING &&
+              field.cpp_string_type() ==
+                  FieldDescriptor::CppStringType::kCord) {
+            return;
+          }
           ctx.Emit(
               R"rs(
               pub fn $raw_field_name$_opt($view_self$) -> $pb$::Optional<$view_type$> {

src/google/protobuf/compiler/rust/oneof.cc

@@ -83,7 +83,9 @@ namespace rust {
 namespace {
 // A user-friendly rust type for a view of this field with lifetime 'msg.
 std::string RsTypeNameView(Context& ctx, const FieldDescriptor& field) {
-  if (field.options().has_ctype()) {
+  if (ctx.is_cpp() && field.cpp_type() == FieldDescriptor::CPPTYPE_STRING &&
+      field.cpp_string_type() != FieldDescriptor::CppStringType::kView &&
+      field.cpp_string_type() != FieldDescriptor::CppStringType::kString) {
     return "";  // TODO: b/308792377 - ctype fields not supported yet.
   }
   switch (GetRustFieldType(field.type())) {