包含子目录以在 ESP-IDF for ESP32 中组织代码

Question

I'm using ESP-IDF 4.3.2 to create an ESP32 project with the following command:

idf.py create-project --path test test

I then modify main/main.c to contain the following code:

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

void app_main(void)
{
    int i = 0;
    while (1) {
        printf("[%d] Hello world!\n", i);
        i++;
        vTaskDelay(5000 / portTICK_PERIOD_MS);
    }
}

This compiles and runs just fine, but if I try to create a subdirectory of main to organise my code I seem to hit an error. I'll add dosomething/printsomething.h and dosomething/printsomething.c with the following contents:

dosomething/printsomething.h :

void printsomething(void);

dosomething/printsomething.c :

#include <stdio.h>

void printsomething(void)
{
    printf("something\n");
}

I then modify main.c as follows:

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#include "dosomething/printsomething.h"

void app_main(void)
{
    int i = 0;
    while (1) {
        printf("[%d] Hello world!\n", i);
        printsomething();
        i++;
        vTaskDelay(5000 / portTICK_PERIOD_MS);
    }
}

The code fails to build and I see an "undefined reference to `printsomething'" error.

/home/builduser/.espressif/tools/xtensa-esp32-elf/esp-2021r2-8.4.0/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld: esp-idf/main/libmain.a(test.c.obj):(.literal.app_main+0x4): undefined reference to `printsomething'
/home/builduser/.espressif/tools/xtensa-esp32-elf/esp-2021r2-8.4.0/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld: esp-idf/main/libmain.a(test.c.obj): in function `app_main':
/home/builduser/Documents/code/esp/esp/test/build/../main/test.c:11: undefined reference to `printsomething'
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.
ninja failed with exit code 1

I can see that the main\CMakeLists.txt file contains the following:

idf_component_register(SRCS "test.c"
                    INCLUDE_DIRS ".")

But I can't find the right syntax for INCLUDE_DIRS which will allow me to specify the directories where the C and Header files are.

Answer 1

Im not exactly familiar with cmake and ESP-IDF . I use platformio in nvim and make . But try create in root directory CMakeLists.txt contains:

PROJECT(test)

SET(DIRS dosomething main)
SUBDIRS(${DIRS})
INCLUDE_DIRECTORIES(${DIRS})

In main directory CMakeLists.txt contains:

ADD_EXECUTABLE(test main.c)
TARGET_LINK_EXECUTABLE(test something)

And in dosomething dir CMakeLists.txt contains:

ADD_LIBRARY(something printsomething.c)

Answer 2

There is a default folder for this. Create a folder called components and place the dosomething folder inside it. The components folder should not be created inside main , but in the same directory as main . So you can use #include "printsomething.h" and everything will work. You don't need to modify your CMakeLists.txt , as components is a default directory. See more here .