Error Code and Helper Functions

[中文]

This section lists definitions of common ESP-IDF error codes and several helper functions related to error handling.

For general information about error codes in ESP-IDF, see Error Handling.

For the full list of error codes defined in ESP-IDF, see Error Codes Reference.

Registering Error Codes

ESP-IDF uses a composable error code registration system that automatically collects error code definitions from all components at build time. This allows esp_err_to_name() and esp_err_to_name_r() to look up error codes defined across the entire project without requiring manual maintenance of a central registry.

How It Works

Error codes are registered at link time using a linker section called .esp_err_msg_tbl. When you define error codes in your component's header files, you need to register those headers with the build system, which will:

  1. Extract the error code definitions during the build

  2. Generate C code that places them into the .esp_err_msg_tbl section

  3. Link them into your application automatically

The linker collects all error code entries from all components into a single array that esp_err_to_name() searches at runtime.

Registering Your Component's Error Codes

To register error codes from your component, add the following line to your component's CMakeLists.txt:

idf_define_esp_err_codes(HEADERS include/my_component.h)

Replace include/my_component.h with the path to your header file(s) that contain error code definitions. You can specify multiple headers:

idf_define_esp_err_codes(HEADERS
    include/my_api.h
    include/my_driver.h
)

The build system will automatically process these headers and register any #define directives that match the error code pattern (typically starting with ESP_ERR_ or similar).

Example

In your component's header file include/my_component.h:

#pragma once

#include "esp_err.h"

#define ESP_ERR_MY_COMPONENT_BASE    0x7000
#define ESP_ERR_MY_COMPONENT_INIT    (ESP_ERR_MY_COMPONENT_BASE + 1)  /*!< Component initialization failed */
#define ESP_ERR_MY_COMPONENT_BUSY    (ESP_ERR_MY_COMPONENT_BASE + 2)  /*!< Component is busy */

In your component's CMakeLists.txt:

idf_component_register(SRCS "my_component.c"
                      INCLUDE_DIRS "include"
                      PRIV_REQUIRES esp_common)

# Register error codes
idf_define_esp_err_codes(HEADERS include/my_component.h)

After building your project, calls to esp_err_to_name(ESP_ERR_MY_COMPONENT_INIT) will return the string "ESP_ERR_MY_COMPONENT_INIT".

Note

Most ESP-IDF components already have their error codes registered. You only need to add idf_define_esp_err_codes() for your own custom components or when adding new error codes to existing components.

API Reference

Header File

Macros

ESP_RETURN_ON_ERROR(x, log_tag, format, ...)

Macro which can be used to check the error code. If the code is not ESP_OK, it prints the message and returns. In the future, we want to switch to C++20. We also want to become compatible with clang. Hence, we provide two versions of the following macros. The first one is using the GNU extension ##__VA_ARGS__. The second one is using the C++20 feature VA_OPT(,). This allows users to compile their code with standard C++20 enabled instead of the GNU extension. Below C++20, we haven't found any good alternative to using ##__VA_ARGS__. Macro which can be used to check the error code. If the code is not ESP_OK, it prints the message and returns.

ESP_RETURN_ON_ERROR_ISR(x, log_tag, format, ...)

A version of ESP_RETURN_ON_ERROR() macro that can be called from ISR.

ESP_RETURN_VOID_ON_ERROR(x, log_tag, format, ...)

Macro which can be used to check the error code. If the code is not ESP_OK, it prints the message and returns. This macro is used when the function returns void.

ESP_RETURN_VOID_ON_ERROR_ISR(x, log_tag, format, ...)

A version of ESP_RETURN_VOID_ON_ERROR() macro that can be called from ISR.

ESP_GOTO_ON_ERROR(x, goto_tag, log_tag, format, ...)

Macro which can be used to check the error code. If the code is not ESP_OK, it prints the message, sets the local variable 'ret' to the code, and then exits by jumping to 'goto_tag'.

ESP_GOTO_ON_ERROR_ISR(x, goto_tag, log_tag, format, ...)

A version of ESP_GOTO_ON_ERROR() macro that can be called from ISR.

ESP_RETURN_ON_FALSE(a, err_code, log_tag, format, ...)

Macro which can be used to check the condition. If the condition is not 'true', it prints the message and returns with the supplied 'err_code'.

ESP_RETURN_ON_FALSE_ISR(a, err_code, log_tag, format, ...)

A version of ESP_RETURN_ON_FALSE() macro that can be called from ISR.

ESP_RETURN_VOID_ON_FALSE(a, log_tag, format, ...)

Macro which can be used to check the condition. If the condition is not 'true', it prints the message and returns without a value.

ESP_RETURN_VOID_ON_FALSE_ISR(a, log_tag, format, ...)

A version of ESP_RETURN_VOID_ON_FALSE() macro that can be called from ISR.

ESP_GOTO_ON_FALSE(a, err_code, goto_tag, log_tag, format, ...)

Macro which can be used to check the condition. If the condition is not 'true', it prints the message, sets the local variable 'ret' to the supplied 'err_code', and then exits by jumping to 'goto_tag'.

ESP_GOTO_ON_FALSE_ISR(a, err_code, goto_tag, log_tag, format, ...)

A version of ESP_GOTO_ON_FALSE() macro that can be called from ISR.

ESP_RETURN_ON_ERROR_CLEANUP(x, ...)

Evaluate an esp_err_t expression, run cleanup on error, and return.

Evaluates x once and stores the result in a local variable err_rc_. If the result is not ESP_OK, the macro:

  • executes the code passed in __VA_ARGS__ (e.g., cleanup functions or logging),

  • returns err_rc_ from the current function. The cleanup code can freely use err_rc_.

Example: 

esp_err_t initialize_device(void)
{
// Simple case: single cleanup action
    ESP_RETURN_ON_ERROR_CLEANUP(open_device("/dev/adc0"), close_device());

// Multiple cleanup actions
    ESP_RETURN_ON_ERROR_CLEANUP(
        allocate_buffer(4096),
        free_buffer(),
        close_device(),
        printf("Failed to initialize sensor: %s\n", esp_err_to_name(err_rc_))
    );

// Complex cleanup with conditional logic and ESP_LOG logging
    ESP_RETURN_ON_ERROR_CLEANUP(
        calibrate_sensor(),
do {
if (err_rc_ == ESP_ERR_INVALID_STATE) {
               ESP_LOGE(TAG, "Sensor in invalid state during calibration");}
            }
            free_buffer();
            close_device();
            ESP_LOGE(TAG, "Drop connection");
        } while (0)
    );

return ESP_OK;
}

Header File

Functions

const char *esp_err_to_name(esp_err_t code)

Returns string for esp_err_t error codes.

This function finds the error code in a lookup-table populated at link time and returns its string representation.

Components register their error codes by calling idf_define_esp_err_codes() in their CMakeLists.txt. The build system extracts error codes from the specified headers and generates entries placed in the .esp_err_msg_tbl linker section.

Parameters:

code -- esp_err_t error code

Returns:

string error message

const char *esp_err_to_name_r(esp_err_t code, char *buf, size_t buflen)

Returns string for esp_err_t and system error codes.

This function finds the error code in a lookup-table populated at link time and returns its string representation. If the error code is not found then it is attempted to be found among system errors.

Components register their error codes by calling idf_define_esp_err_codes() in their CMakeLists.txt.

Parameters:

  • code -- esp_err_t error code

  • buf -- [out] buffer where the error message should be written

  • buflen -- Size of buffer buf. At most buflen bytes are written into the buf buffer (including the terminating null byte).

Returns:

buf containing the string error message

Macros

ESP_OK

esp_err_t value indicating success (no error)

ESP_FAIL

Generic esp_err_t code indicating failure

ESP_ERR_NO_MEM

Out of memory

ESP_ERR_INVALID_ARG

Invalid argument

ESP_ERR_INVALID_STATE

Invalid state

ESP_ERR_INVALID_SIZE

Invalid size

ESP_ERR_NOT_FOUND

Requested resource not found

ESP_ERR_NOT_SUPPORTED

Operation or feature not supported

ESP_ERR_TIMEOUT

Operation timed out

ESP_ERR_INVALID_RESPONSE

Received response was invalid

ESP_ERR_INVALID_CRC

CRC or checksum was invalid

ESP_ERR_INVALID_VERSION

Version was invalid

ESP_ERR_INVALID_MAC

MAC address was invalid

ESP_ERR_NOT_FINISHED

Operation has not fully completed

ESP_ERR_NOT_ALLOWED

Operation is not allowed

ESP_ERR_WIFI_BASE

Starting number of WiFi error codes

ESP_ERR_MESH_BASE

Starting number of MESH error codes

ESP_ERR_FLASH_BASE

Starting number of flash error codes

ESP_ERR_HW_CRYPTO_BASE

Starting number of HW cryptography module error codes

ESP_ERR_MEMPROT_BASE

Starting number of Memory Protection API error codes

ESP_ERROR_CHECK(x)

Macro which can be used to check the error code, and terminate the program in case the code is not ESP_OK. Prints the error code, error location, and the failed statement to serial output.

Disabled if assertions are disabled.

ESP_ERROR_CHECK_WITHOUT_ABORT(x)

Macro which can be used to check the error code. Prints the error code, error location, and the failed statement to serial output. In comparison with ESP_ERROR_CHECK(), this prints the same error message but isn't terminating the program.

Type Definitions

typedef int esp_err_t

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