Mac 15.3.1 (24D70), error: void value not ignored as it ought to be (MEGH-6407)

[dzungpv]

Answers checklist.

• I have read the Rainmaker documentation and the issue is not addressed there.
• I have updated my IDF branch (release/vX.Y) to the latest version and checked that the issue is present there. This is not applicable if you are using Rainmaker with Arduino.
• I have searched the Rainmaker forum and issue tracker for a similar issue and not found a similar issue.

IDF / ESP32-Arduino version.

v5.3

Operating System used.

macOS

How did you build your project?

Command line with idf.py

Development Kit.

ESP32 DEV

What is the expected behavior?

Build error on the MacOs

/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_node_config.c: In function '__esp_rmaker_get_node_config':
/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_node_config.c:271:12: error: void value not ignored as it ought to be
  271 |     return json_gen_str_end(&jstr);
      |            ^~~~~~~~~~~~~~~~~~~~~~~
/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_node_config.c:272:1: error: control reaches end of non-void function [-Werror=return-type]
  272 | }
      | ^

2, I try to fix 1 error show this error

/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_param.c: In function 'esp_rmaker_populate_params':
/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_param.c:165:14: error: void value not ignored as it ought to be
  165 |     *buf_len = json_gen_str_end(&jstr);
      |              ^

On the previous version of Mac it working fine, code is latest from this repo

What is the actual behavior?

Build should work

Steps to reproduce.

Build sample homekit_switch

Build Logs.

1.

/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_node_config.c: In function '__esp_rmaker_get_node_config':
/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_node_config.c:271:12: error: void value not ignored as it ought to be
  271 |     return json_gen_str_end(&jstr);
      |            ^~~~~~~~~~~~~~~~~~~~~~~
/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_node_config.c:272:1: error: control reaches end of non-void function [-Werror=return-type]
  272 | }
      | ^


2, I try to fix 1 error show this error

/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_param.c: In function 'esp_rmaker_populate_params':
/Users/vietdzung/dev/projects/esp32/sdks/5.3.2/esp-rainmaker/components/esp_rainmaker/src/core/esp_rmaker_param.c:165:14: error: void value not ignored as it ought to be
  165 |     *buf_len = json_gen_str_end(&jstr);
      |              ^

More Information.

No response

[vikramdattu]

@dzungpv the error means, the compiler thinks json_gen_str_end returns no value (i.e., void) but we are catching the return value. This is of course, wrong as the API returns the length of the json string.

Q: Did you modify the above said API's return value to be void?

[dzungpv]

No, it is original code. Strange that it only show error with MacOSx 15.3.1 I have other Mac with 15.3.0 and not error with same code. May be gcc on 15.3.1 change. I try on Windows 11 it build ok too. I forgot to mention that I also using Arduino as IDF component with the sample.

[vikramdattu]

Thanks for the confirmation! Strange behaviour indeed. If you are already using the IDF build system, using Arduino in the mix seems an odd choice. I am not sure, how and why you are putting it all together.

Few suggestions:

• Please do a grep for json_gen_str_end in all of your example sources and see if you hit something useful?
• Can you try your project with just the ESP-IDF (no Arduino) or would that be too much of a change?

[dzungpv]

Thanks for the confirmation! Strange behaviour indeed. If you are already using the IDF build system, using Arduino in the mix seems an odd choice. I am not sure, how and why you are putting it all together.

Few suggestions:

* Please do a grep for `json_gen_str_end` in all of your example sources and see if you hit something useful?

* Can you try your project with just the ESP-IDF (no Arduino) or would that be too much of a change?

This is output of : grep -r -n "json_gen_str_end" . command

% grep -r -n "json_gen_str_end" .
./build/log/idf_py_stdout_output_4937:1791:  165 |     *buf_len = json_gen_str_end(&jstr);
./build/log/idf_py_stdout_output_4937:1798:  271 |     return json_gen_str_end(&jstr);
./build/log/idf_py_stdout_output_4937:1816:  901 |     *buf_size = json_gen_str_end(&jstr);
Binary file ./build/esp-idf/esp_hap_core/CMakeFiles/__idf_esp_hap_core.dir/src/esp_hap_ip_services.c.obj matches
Binary file ./build/esp-idf/esp_rainmaker/CMakeFiles/__idf_esp_rainmaker.dir/src/core/esp_rmaker_user_mapping.c.obj matches
Binary file ./build/esp-idf/json_generator/libjson_generator.a matches
Binary file ./build/esp-idf/json_generator/CMakeFiles/__idf_json_generator.dir/upstream/json_generator.c.obj matches

I use Arduino component because I using some libs, it writing in Arduino. I have use it for years without any issue, it is just a component lime esp-rainmaker. https://components.espressif.com/components/espressif/arduino-esp32/versions/3.1.2?language=en
https://docs.espressif.com/projects/arduino-esp32/en/latest/esp-idf_component.html