Enum generation is not supported correctly

[VishalDevnale]

Hi,
I have enum defined inside module and same enum is used inside a struct.

My IDL file looks like this:

module std_msgs { module msg { 

enum Number{
  ONE,
  TWO,
  THREE, 
  FOURTH,   
  FIFTH 
};
 
struct Header {
    std_msgs::msg::Number VariableSpeedSign_element;
    std_msgs::msg::Time stamp; 
    string frame_id; 
}; 
 
}; };  // module msg::std_msgs

Generated code looks like:

typedef enum Number
{
    ONE,
    TWO,
    THREE,
    FOURTH,
    FIFTH
} Number;

typedef uint32_t Number_cdr;
typedef struct std_msgs_msg_Header
{
    std_msgs::msg::Number_cdr VariableSpeedSign_element;
    std_msgs_msg_Time stamp;
    char frame_id[255];

} std_msgs_msg_Header;

struct ucdrBuffer;

bool std_msgs_msg_Header_serialize_topic(struct ucdrBuffer* writer, const std_msgs_msg_Header* topic);
bool std_msgs_msg_Header_deserialize_topic(struct ucdrBuffer* reader, std_msgs_msg_Header* topic);
uint32_t std_msgs_msg_Header_size_of_topic(const std_msgs_msg_Header* topic, uint32_t size);

In the above code struct element VariableSpeedSign_element type is generated wrongly. Could you please take a look at it?
Let me know if I am doing anything wrong.

[pablogs9]

I have added a commit fixing this here: #74

Could you test and confirm that it fixes your issue?

[Ryanf55]

Does this also fix the issue that defaults aren't used? The generated goemetry_msgs/msg/Quaternion is therefore not normalized and breaks other tooling. You have to manually set the fields to the defaults already specified in the IDL because it's unititialized.

See /opt/ros/humble/include/geometry_msgs/geometry_msgs/msg/detail/quaternion__struct.hpp in ros:humble docker image:
docker run -it ros:humble cat cat /opt/ros/humble/include/geometry_msgs/geometry_msgs/msg/detail/quaternion__struct.hpp

And, compare it to the generated type from MicroXRCEDDSGen:

// Copyright 2016 Proyectos y Sistemas de Mantenimiento SL (eProsima).
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/*!
 * @file Quaternion.h
 * This header file contains the declaration of the described types in the IDL file.
 *
 * This file was generated by the tool microxrceddsgen.
 */

#ifndef _Quaternion_H_
#define _Quaternion_H_

#ifdef __cplusplus
extern "C"
{
#endif

#include <stdint.h>
#include <stdbool.h>

typedef struct geometry_msgs_msg_Quaternion
{
    double x;

    double y;

    double z;

    double w;

} geometry_msgs_msg_Quaternion;

struct ucdrBuffer;
bool geometry_msgs_msg_Quaternion_serialize_topic(struct ucdrBuffer* writer, const geometry_msgs_msg_Quaternion* topic);
bool geometry_msgs_msg_Quaternion_deserialize_topic(struct ucdrBuffer* reader, geometry_msgs_msg_Quaternion* topic);
uint32_t geometry_msgs_msg_Quaternion_size_of_topic(const geometry_msgs_msg_Quaternion* topic, uint32_t size);

#ifdef __cplusplus
}
#endif

#endif // _Quaternion_H_

[pablogs9]

You have to manually set the fields to the defaults already specified in the IDL because it's unititialized.

Since this generator targets C99 code generation, at most we can create a utility that fills the struct members with defaults values. As far as I see it is not possible to have something like inherent initialization in a C struct.