Add to_proto to descriptor classes (protocolbuffers#19971)

Some APIs (e.g. [BigQuery Storage](https://github.com/googleapis/googleapis/blob/ab61c52324b39d1c8619a96ab19cc6c173b13f2c/google/cloud/bigquery/storage/v1/protobuf.proto#L39)) use DescriptorProto for schema descriptions. But,  in Ruby, there are no methods for that so far.

This PR implements the method for that(`to_proto`) to descriptor classes.

Fixes protocolbuffers#12044.

Closes protocolbuffers#19971

PiperOrigin-RevId: 723149905

Author: y-yagi

php/ext/google/protobuf/php-upb.c

@@ -15420,7 +15420,7 @@ bool upb_FileDef_Resolves(const upb_FileDef* f, const char* path) {
   return false;
 }
 
-static char* strviewdup(upb_DefBuilder* ctx, upb_StringView view) {
+static char* _strviewdup(upb_DefBuilder* ctx, upb_StringView view) {
   char* ret = upb_strdup2(view.data, view.size, _upb_DefBuilder_Arena(ctx));
   if (!ret) _upb_DefBuilder_OomErr(ctx);
   return ret;
@@ -15549,7 +15549,7 @@ void _upb_FileDef_Create(upb_DefBuilder* ctx,
   }
 
   upb_StringView name = UPB_DESC(FileDescriptorProto_name)(file_proto);
-  file->name = strviewdup(ctx, name);
+  file->name = _strviewdup(ctx, name);
   if (strlen(file->name) != name.size) {
     _upb_DefBuilder_Errf(ctx, "File name contained embedded NULL");
   }
@@ -15558,7 +15558,7 @@ void _upb_FileDef_Create(upb_DefBuilder* ctx,
 
   if (package.size) {
     _upb_DefBuilder_CheckIdentFull(ctx, package);
-    file->package = strviewdup(ctx, package);
+    file->package = _strviewdup(ctx, package);
   } else {
     file->package = NULL;
   }

ruby/ext/google/protobuf_c/defs.c

@@ -451,6 +451,27 @@ static VALUE Descriptor_options(VALUE _self) {
   return message_options;
 }
 
+/*
+ * call-seq:
+ *     Descriptor.to_proto => DescriptorProto
+ *
+ * Returns the `DescriptorProto` of this `Descriptor`.
+ */
+static VALUE Descriptor_to_proto(VALUE _self) {
+  Descriptor* self = ruby_to_Descriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_DescriptorProto* proto =
+      upb_MessageDef_ToProto(self->msgdef, arena);
+  size_t size;
+  const char* serialized =
+      google_protobuf_DescriptorProto_serialize(proto, arena, &size);
+  VALUE proto_class = rb_path2class("Google::Protobuf::DescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 static void Descriptor_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "Descriptor", rb_cObject);
   rb_define_alloc_func(klass, Descriptor_alloc);
@@ -463,6 +484,7 @@ static void Descriptor_register(VALUE module) {
   rb_define_method(klass, "name", Descriptor_name, 0);
   rb_define_method(klass, "file_descriptor", Descriptor_file_descriptor, 0);
   rb_define_method(klass, "options", Descriptor_options, 0);
+  rb_define_method(klass, "to_proto", Descriptor_to_proto, 0);
   rb_include_module(klass, rb_mEnumerable);
   rb_gc_register_address(&cDescriptor);
   cDescriptor = klass;
@@ -558,12 +580,37 @@ static VALUE FileDescriptor_options(VALUE _self) {
   return file_options;
 }
 
+/*
+ * call-seq:
+ *     FileDescriptor.to_proto => FileDescriptorProto
+ *
+ * Returns the `FileDescriptorProto` of this `FileDescriptor`.
+ */
+static VALUE FileDescriptor_to_proto(VALUE _self) {
+  FileDescriptor* self = ruby_to_FileDescriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_FileDescriptorProto* file_proto =
+      upb_FileDef_ToProto(self->filedef, arena);
+
+  size_t size;
+  const char* serialized =
+      google_protobuf_FileDescriptorProto_serialize(file_proto, arena, &size);
+
+  VALUE file_proto_class =
+      rb_path2class("Google::Protobuf::FileDescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, file_proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 static void FileDescriptor_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "FileDescriptor", rb_cObject);
   rb_define_alloc_func(klass, FileDescriptor_alloc);
   rb_define_method(klass, "initialize", FileDescriptor_initialize, 3);
   rb_define_method(klass, "name", FileDescriptor_name, 0);
   rb_define_method(klass, "options", FileDescriptor_options, 0);
+  rb_define_method(klass, "to_proto", FileDescriptor_to_proto, 0);
   rb_gc_register_address(&cFileDescriptor);
   cFileDescriptor = klass;
 }
@@ -956,6 +1003,27 @@ static VALUE FieldDescriptor_options(VALUE _self) {
   return field_options;
 }
 
+/*
+ * call-seq:
+ *     FieldDescriptor.to_proto => FieldDescriptorProto
+ *
+ * Returns the `FieldDescriptorProto` of this `FieldDescriptor`.
+ */
+static VALUE FieldDescriptor_to_proto(VALUE _self) {
+  FieldDescriptor* self = ruby_to_FieldDescriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_FieldDescriptorProto* proto =
+      upb_FieldDef_ToProto(self->fielddef, arena);
+  size_t size;
+  const char* serialized =
+      google_protobuf_FieldDescriptorProto_serialize(proto, arena, &size);
+  VALUE proto_class = rb_path2class("Google::Protobuf::FieldDescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 static void FieldDescriptor_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "FieldDescriptor", rb_cObject);
   rb_define_alloc_func(klass, FieldDescriptor_alloc);
@@ -975,6 +1043,7 @@ static void FieldDescriptor_register(VALUE module) {
   rb_define_method(klass, "get", FieldDescriptor_get, 1);
   rb_define_method(klass, "set", FieldDescriptor_set, 2);
   rb_define_method(klass, "options", FieldDescriptor_options, 0);
+  rb_define_method(klass, "to_proto", FieldDescriptor_to_proto, 0);
   rb_gc_register_address(&cFieldDescriptor);
   cFieldDescriptor = klass;
 }
@@ -1093,13 +1162,35 @@ static VALUE OneOfDescriptor_options(VALUE _self) {
   return oneof_options;
 }
 
+/*
+ * call-seq:
+ *     OneofDescriptor.to_proto => OneofDescriptorProto
+ *
+ * Returns the `OneofDescriptorProto` of this `OneofDescriptor`.
+ */
+static VALUE OneOfDescriptor_to_proto(VALUE _self) {
+  OneofDescriptor* self = ruby_to_OneofDescriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_OneofDescriptorProto* proto =
+      upb_OneofDef_ToProto(self->oneofdef, arena);
+  size_t size;
+  const char* serialized =
+      google_protobuf_OneofDescriptorProto_serialize(proto, arena, &size);
+  VALUE proto_class = rb_path2class("Google::Protobuf::OneofDescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 static void OneofDescriptor_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "OneofDescriptor", rb_cObject);
   rb_define_alloc_func(klass, OneofDescriptor_alloc);
   rb_define_method(klass, "initialize", OneofDescriptor_initialize, 3);
   rb_define_method(klass, "name", OneofDescriptor_name, 0);
   rb_define_method(klass, "each", OneofDescriptor_each, 0);
   rb_define_method(klass, "options", OneOfDescriptor_options, 0);
+  rb_define_method(klass, "to_proto", OneOfDescriptor_to_proto, 0);
   rb_include_module(klass, rb_mEnumerable);
   rb_gc_register_address(&cOneofDescriptor);
   cOneofDescriptor = klass;
@@ -1298,6 +1389,29 @@ static VALUE EnumDescriptor_options(VALUE _self) {
   return enum_options;
 }
 
+/*
+ * call-seq:
+ *     EnumDescriptor.to_proto => EnumDescriptorProto
+ *
+ * Returns the `EnumDescriptorProto` of this `EnumDescriptor`.
+ */
+static VALUE EnumDescriptor_to_proto(VALUE _self) {
+  EnumDescriptor* self = ruby_to_EnumDescriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_EnumDescriptorProto* proto =
+      upb_EnumDef_ToProto(self->enumdef, arena);
+
+  size_t size;
+  const char* serialized =
+      google_protobuf_EnumDescriptorProto_serialize(proto, arena, &size);
+
+  VALUE proto_class = rb_path2class("Google::Protobuf::EnumDescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 static void EnumDescriptor_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "EnumDescriptor", rb_cObject);
   rb_define_alloc_func(klass, EnumDescriptor_alloc);
@@ -1310,6 +1424,7 @@ static void EnumDescriptor_register(VALUE module) {
   rb_define_method(klass, "file_descriptor", EnumDescriptor_file_descriptor, 0);
   rb_define_method(klass, "is_closed?", EnumDescriptor_is_closed, 0);
   rb_define_method(klass, "options", EnumDescriptor_options, 0);
+  rb_define_method(klass, "to_proto", EnumDescriptor_to_proto, 0);
   rb_include_module(klass, rb_mEnumerable);
   rb_gc_register_address(&cEnumDescriptor);
   cEnumDescriptor = klass;
@@ -1438,6 +1553,27 @@ static VALUE ServiceDescriptor_options(VALUE _self) {
   return service_options;
 }
 
+/*
+ * call-seq:
+ *     ServiceDescriptor.to_proto => ServiceDescriptorProto
+ *
+ * Returns the `ServiceDescriptorProto` of this `ServiceDescriptor`.
+ */
+static VALUE ServiceDescriptor_to_proto(VALUE _self) {
+  ServiceDescriptor* self = ruby_to_ServiceDescriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_ServiceDescriptorProto* proto =
+      upb_ServiceDef_ToProto(self->servicedef, arena);
+  size_t size;
+  const char* serialized =
+      google_protobuf_ServiceDescriptorProto_serialize(proto, arena, &size);
+  VALUE proto_class = rb_path2class("Google::Protobuf::ServiceDescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 static void ServiceDescriptor_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "ServiceDescriptor", rb_cObject);
   rb_define_alloc_func(klass, ServiceDescriptor_alloc);
@@ -1447,6 +1583,7 @@ static void ServiceDescriptor_register(VALUE module) {
   rb_define_method(klass, "file_descriptor", ServiceDescriptor_file_descriptor,
                    0);
   rb_define_method(klass, "options", ServiceDescriptor_options, 0);
+  rb_define_method(klass, "to_proto", ServiceDescriptor_to_proto, 0);
   rb_include_module(klass, rb_mEnumerable);
   rb_gc_register_address(&cServiceDescriptor);
   cServiceDescriptor = klass;
@@ -1580,6 +1717,27 @@ static VALUE MethodDescriptor_client_streaming(VALUE _self) {
   return upb_MethodDef_ClientStreaming(self->methoddef) ? Qtrue : Qfalse;
 }
 
+/*
+ * call-seq:
+ *     MethodDescriptor.to_proto => MethodDescriptorProto
+ *
+ * Returns the `MethodDescriptorProto` of this `MethodDescriptor`.
+ */
+static VALUE MethodDescriptor_to_proto(VALUE _self) {
+  MethodDescriptor* self = ruby_to_MethodDescriptor(_self);
+  upb_Arena* arena = upb_Arena_New();
+  google_protobuf_MethodDescriptorProto* proto =
+      upb_MethodDef_ToProto(self->methoddef, arena);
+  size_t size;
+  const char* serialized =
+      google_protobuf_MethodDescriptorProto_serialize(proto, arena, &size);
+  VALUE proto_class = rb_path2class("Google::Protobuf::MethodDescriptorProto");
+  VALUE proto_rb =
+      Message_decode_bytes(size, serialized, 0, proto_class, false);
+  upb_Arena_Free(arena);
+  return proto_rb;
+}
+
 /*
  * call-seq:
  *      MethodDescriptor.server_streaming => bool
@@ -1603,6 +1761,7 @@ static void MethodDescriptor_register(VALUE module) {
                    0);
   rb_define_method(klass, "server_streaming", MethodDescriptor_server_streaming,
                    0);
+  rb_define_method(klass, "to_proto", MethodDescriptor_to_proto, 0);
   rb_gc_register_address(&cMethodDescriptor);
   cMethodDescriptor = klass;
 }

ruby/ext/google/protobuf_c/glue.c

@@ -26,13 +26,31 @@ char* EnumDescriptor_serialized_options(const upb_EnumDef* enumdef,
   return serialized;
 }
 
+char* EnumDescriptor_serialized_to_proto(const upb_EnumDef* enumdef,
+                                         size_t* size, upb_Arena* arena) {
+  const google_protobuf_EnumDescriptorProto* file_proto =
+      upb_EnumDef_ToProto(enumdef, arena);
+  char* serialized =
+      google_protobuf_EnumDescriptorProto_serialize(file_proto, arena, size);
+  return serialized;
+}
+
 char* FileDescriptor_serialized_options(const upb_FileDef* filedef,
                                         size_t* size, upb_Arena* arena) {
   const google_protobuf_FileOptions* opts = upb_FileDef_Options(filedef);
   char* serialized = google_protobuf_FileOptions_serialize(opts, arena, size);
   return serialized;
 }
 
+char* FileDescriptor_serialized_to_proto(const upb_FileDef* filedef,
+                                         size_t* size, upb_Arena* arena) {
+  const google_protobuf_FileDescriptorProto* file_proto =
+      upb_FileDef_ToProto(filedef, arena);
+  char* serialized =
+      google_protobuf_FileDescriptorProto_serialize(file_proto, arena, size);
+  return serialized;
+}
+
 char* Descriptor_serialized_options(const upb_MessageDef* msgdef, size_t* size,
                                     upb_Arena* arena) {
   const google_protobuf_MessageOptions* opts = upb_MessageDef_Options(msgdef);
@@ -41,20 +59,47 @@ char* Descriptor_serialized_options(const upb_MessageDef* msgdef, size_t* size,
   return serialized;
 }
 
+char* Descriptor_serialized_to_proto(const upb_MessageDef* msgdef, size_t* size,
+                                     upb_Arena* arena) {
+  const google_protobuf_DescriptorProto* proto =
+      upb_MessageDef_ToProto(msgdef, arena);
+  char* serialized =
+      google_protobuf_DescriptorProto_serialize(proto, arena, size);
+  return serialized;
+}
+
 char* OneOfDescriptor_serialized_options(const upb_OneofDef* oneofdef,
                                          size_t* size, upb_Arena* arena) {
   const google_protobuf_OneofOptions* opts = upb_OneofDef_Options(oneofdef);
   char* serialized = google_protobuf_OneofOptions_serialize(opts, arena, size);
   return serialized;
 }
 
+char* OneOfDescriptor_serialized_to_proto(const upb_OneofDef* oneofdef,
+                                          size_t* size, upb_Arena* arena) {
+  const google_protobuf_OneofDescriptorProto* proto =
+      upb_OneofDef_ToProto(oneofdef, arena);
+  char* serialized =
+      google_protobuf_OneofDescriptorProto_serialize(proto, arena, size);
+  return serialized;
+}
+
 char* FieldDescriptor_serialized_options(const upb_FieldDef* fielddef,
                                          size_t* size, upb_Arena* arena) {
   const google_protobuf_FieldOptions* opts = upb_FieldDef_Options(fielddef);
   char* serialized = google_protobuf_FieldOptions_serialize(opts, arena, size);
   return serialized;
 }
 
+char* FieldDescriptor_serialized_to_proto(const upb_FieldDef* fieldef,
+                                          size_t* size, upb_Arena* arena) {
+  const google_protobuf_FieldDescriptorProto* proto =
+      upb_FieldDef_ToProto(fieldef, arena);
+  char* serialized =
+      google_protobuf_FieldDescriptorProto_serialize(proto, arena, size);
+  return serialized;
+}
+
 char* ServiceDescriptor_serialized_options(const upb_ServiceDef* servicedef,
                                            size_t* size, upb_Arena* arena) {
   const google_protobuf_ServiceOptions* opts =
@@ -64,9 +109,27 @@ char* ServiceDescriptor_serialized_options(const upb_ServiceDef* servicedef,
   return serialized;
 }
 
+char* ServiceDescriptor_serialized_to_proto(const upb_ServiceDef* servicedef,
+                                            size_t* size, upb_Arena* arena) {
+  const google_protobuf_ServiceDescriptorProto* proto =
+      upb_ServiceDef_ToProto(servicedef, arena);
+  char* serialized =
+      google_protobuf_ServiceDescriptorProto_serialize(proto, arena, size);
+  return serialized;
+}
+
 char* MethodDescriptor_serialized_options(const upb_MethodDef* methoddef,
                                           size_t* size, upb_Arena* arena) {
   const google_protobuf_MethodOptions* opts = upb_MethodDef_Options(methoddef);
   char* serialized = google_protobuf_MethodOptions_serialize(opts, arena, size);
   return serialized;
 }
+
+char* MethodDescriptor_serialized_to_proto(const upb_MethodDef* methodef,
+                                           size_t* size, upb_Arena* arena) {
+  const google_protobuf_MethodDescriptorProto* proto =
+      upb_MethodDef_ToProto(methodef, arena);
+  char* serialized =
+      google_protobuf_MethodDescriptorProto_serialize(proto, arena, size);
+  return serialized;
+}