ESP32 Forum

Posted: **Fri Feb 01, 2019 5:04 am**

Hi guys.

When I tried to compile my source, it failed saying

undefined reference to `test_func'

.

Here is my directory structure.

- esp-idf
- my_lib
---- test_func.h
---- test_func.c
- my_project
---- main
-------- main.c

Here is main.c source code.

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_log.h"
#include "sdkconfig.h"
#include "../../my_lib/test_func.h"

void app_main()
{
	test_func();
}

Here is test_func.h source code.

Code: Select all

void test_func(void);

Here is test_func.c source code.

Code: Select all

#include "esp_log.h"
#include "test_func.h"

void test_func() {
	ESP_LOGI("TEST", "TEST");
}

What is wrong?
Sorry for such a beginner question, but I'm not used to c programming.

Posted: **Fri Feb 01, 2019 7:07 am**

my_lib is not 'seen' by the make system. Either put test_func.* in the main/ folder, or make my_lib into a proper component that's either placed under your my_project/components/ folder, or use EXTRA_COMPONENT_DIRS to refer to it. In general, I'd suggest you give https://docs.espressif.com/projects/esp ... ystem.html a good read-through, as it tells you exactly what the build system expects.

Posted: **Fri Feb 08, 2019 7:18 am**

Dear ESP Sprite, Thank you for your reply.

I learnt the build system and I put files in my project folder.

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