Self Describing Error Code Enum Macro (Or other status tracking variables) V2

augmented_enum_macro_error_code.c

///usr/bin/env ccache gcc -Wall -Wextra -Werror -O3 -std=gnu17 "$0" -o /tmp/a -lm && /tmp/a "$@"; exit
#include <stdint.h>
#include <stdio.h>

/*
    Self Describing Error Code Enum Macro (Or other status tracking variables) V2
    Author: Brian Khuu (2024)

    This is an idea I got for easier management of error codes and other enums.
    The benefit of this approach is that it provides a way of having self
    documenting enumerated values which would be useful for debug loggers.

    Ergo, your debug log could print the meaning of an error or status message.

    This is my second approach using other macro tips suggested by peeps from 
    the redbean discord server.
 */

/******************************************************************************/

/*
  AUGMENTED ENUM MACROS
*/

// Augmented Enumerated List
#define DEFINE_AUG_ENUM_TYPE_ENTRY(CODE, NAME, DESC, ...) CODE,
#define DEFINE_AUG_ENUM_TYPE(ENUM_NAME, SET)                                   \
  typedef enum ENUM_NAME { SET(DEFINE_AUG_ENUM_TYPE_ENTRY) } ENUM_NAME

// Augmented Enum Retrieve String Name Function
#define DEFINE_AUG_ENUM_NAME_STRING_FUNC_ENTRY(CODE, NAME, DESC, ...)          \
  case CODE:                                                                   \
    return NAME ? NAME : "?";
#define DEFINE_AUG_ENUM_NAME_STRING_FUNC(FUNCNAME, ENUM_NAME, SET)             \
  const char *FUNCNAME(enum ENUM_NAME code) {                                  \
    switch (code) {                                                            \
      SET(DEFINE_AUG_ENUM_NAME_STRING_FUNC_ENTRY)                              \
    default:                                                                   \
      return "?";                                                              \
    }                                                                          \
  }

// Augmented Enum Retrieve String Description Function
#define DEFINE_AUG_ENUM_DESC_STRING_FUNC_ENTRY(CODE, NAME, DESC, ...)          \
  case CODE:                                                                   \
    return DESC ? DESC : "?";
#define DEFINE_AUG_ENUM_DESC_STRING_FUNC(FUNCNAME, ENUM_NAME, SET)             \
  const char *FUNCNAME(enum ENUM_NAME code) {                                  \
    switch (code) {                                                            \
      SET(DEFINE_AUG_ENUM_DESC_STRING_FUNC_ENTRY)                              \
    default:                                                                   \
      return "?";                                                              \
    }                                                                          \
  }

// Augmented Enum Retrieve Name and Description Function
#define GENERATE_AUG_ENUM_FUNC(ENUM_NAME, SET)                                 \
  DEFINE_AUG_ENUM_NAME_STRING_FUNC(ENUM_NAME##_name_to_str, ENUM_NAME, SET);   \
  DEFINE_AUG_ENUM_DESC_STRING_FUNC(ENUM_NAME##_desc_to_str, ENUM_NAME, SET);

// Augmented Enum Call Retrieve Name Function
#define augmented_enum_to_name_str(ENUM_NAME, value)                           \
  ENUM_NAME##_name_to_str(value)

// Augmented Enum Call Retrieve Description Function
#define augmented_enum_to_desc_str(ENUM_NAME, value)                           \
  ENUM_NAME##_desc_to_str(value)

/******************************************************************************/

/*
  AUGMENTED ENUM BASED ERROR CODE
*/

/* USER WOULD ADD NEW CONTEXT AND SUBSYSTEM CODES HERE */
#define ERROR_CODE_CONTEXT_SET(X)                                              \
  X(ERROR_CODE_CONTEXT_SUBSYS1, "C1", "Error Context Description 1")           \
  X(ERROR_CODE_CONTEXT_SUBSYS2, "C2", "Error Context Description 2")

#define ERROR_SUBSYS1_SET(X)                                                   \
  X(ERROR_SUBSYS1_TEST1, "T1", "Error Description C1T1")                       \
  X(ERROR_SUBSYS1_TEST2, "T2", "Error Description C1T2")                       \
  X(ERROR_SUBSYS1_TEST3, "T3", "Error Description C1T3")

#define ERROR_SUBSYS2_SET(X)                                                   \
  X(ERROR_SUBSYS2_TEST1, "T1", "Error Description C2T1")                       \
  X(ERROR_SUBSYS2_TEST2, "T2", "Error Description C2T2")                       \
  X(ERROR_SUBSYS2_TEST3, "T3", "Error Description C2T3")

/* Define Error Code Type */
#define ERROR_SUBCODE_SIZE (16) // Define the context vs subcode split
typedef uint32_t ErrorCode;
typedef uint16_t ErrorContext;
typedef uint16_t ErrorSubCode;

/* Define Error Code Enums */
DEFINE_AUG_ENUM_TYPE(ErrorCodeContext, ERROR_CODE_CONTEXT_SET);
DEFINE_AUG_ENUM_TYPE(ErrorSubsys1, ERROR_SUBSYS1_SET);
DEFINE_AUG_ENUM_TYPE(ErrorSubsys2, ERROR_SUBSYS2_SET);

/* Generate Error Code To String Functions */
GENERATE_AUG_ENUM_FUNC(ErrorCodeContext, ERROR_CODE_CONTEXT_SET);
GENERATE_AUG_ENUM_FUNC(ErrorSubsys1, ERROR_SUBSYS1_SET);
GENERATE_AUG_ENUM_FUNC(ErrorSubsys2, ERROR_SUBSYS2_SET);

/* Convert error context and error subcode to error code */
#define CREATE_ERROR_CODE(CONTEXT, SUBCODE)                                    \
  (((ErrorCode)(CONTEXT) << ERROR_SUBCODE_SIZE) | (ErrorCode)(SUBCODE))

/* Convert error code to error context or error subcode */
#define GET_ERROR_CONTEXT(CODE) (CODE >> ERROR_SUBCODE_SIZE)
#define GET_ERROR_SUBCODE(CODE) (CODE & ((1 << ERROR_SUBCODE_SIZE) - 1))

/******************************************************************************/

const char *error_code_to_context_str(const ErrorCode error_code) {
  return augmented_enum_to_name_str(ErrorCodeContext,
                                    GET_ERROR_CONTEXT(error_code));
}

const char *error_code_to_subcode_name_str(const ErrorCode error_code) {
  ErrorCodeContext context = GET_ERROR_CONTEXT(error_code);
  ErrorSubCode subcode = GET_ERROR_SUBCODE(error_code);
  switch (context) {
  case ERROR_CODE_CONTEXT_SUBSYS1:
    return augmented_enum_to_name_str(ErrorSubsys1, subcode);
  case ERROR_CODE_CONTEXT_SUBSYS2:
    return augmented_enum_to_name_str(ErrorSubsys2, subcode);
  default:
    return "?";
  }
}

const char *error_code_to_subcode_description_str(const ErrorCode error_code) {
  ErrorCodeContext context = GET_ERROR_CONTEXT(error_code);
  ErrorSubCode subcode = GET_ERROR_SUBCODE(error_code);
  switch (context) {
  case ERROR_CODE_CONTEXT_SUBSYS1:
    return augmented_enum_to_desc_str(ErrorSubsys1, subcode);
  case ERROR_CODE_CONTEXT_SUBSYS2:
    return augmented_enum_to_desc_str(ErrorSubsys2, subcode);
  default:
    return "?";
  }
}

/******************************************************************************/

/*
  Example Usage Of This Error Code based Augmented Enum
 */

const ErrorCodeContext error_context_list[] = {
#define ERROR_CODE_LIST(CODE, NAME, DESC) CODE,
    ERROR_CODE_CONTEXT_SET(ERROR_CODE_LIST)
#undef ERROR_CODE_LIST
};
#define ERROR_CONTEXT_LIST_SIZE (sizeof(error_context_list) / sizeof(error_context_list[0]))

const ErrorCode error_code_list[] = {
#define ERROR_CODE_LIST(CODE, NAME, DESC) CREATE_ERROR_CODE(ERROR_CODE_CONTEXT_SUBSYS1, CODE),
    ERROR_SUBSYS1_SET(ERROR_CODE_LIST)
#undef ERROR_CODE_LIST
#define ERROR_CODE_LIST(CODE, NAME, DESC) CREATE_ERROR_CODE(ERROR_CODE_CONTEXT_SUBSYS2, CODE),
        ERROR_SUBSYS2_SET(ERROR_CODE_LIST)
#undef ERROR_CODE_LIST
};
#define ERROR_CODE_LIST_SIZE (sizeof(error_code_list) / sizeof(error_code_list[0]))

int main(void) {

  printf("\n# Context Code List\n");
  for (size_t i = 0; i < ERROR_CONTEXT_LIST_SIZE; i++) {
    const ErrorContext context = error_context_list[i];
    printf("| context number: %d | context name: %s | context description: '%s' |\n", context, augmented_enum_to_name_str(ErrorCodeContext, context), augmented_enum_to_desc_str(ErrorCodeContext, context));
  }

  printf("\n# Error Code List\n");

  for (size_t i = 0; i < ERROR_CODE_LIST_SIZE; i++) {
    const ErrorCode error_code = error_code_list[i];
    const ErrorContext context = GET_ERROR_CONTEXT(error_code);
    const ErrorSubCode subcode = GET_ERROR_SUBCODE(error_code);
    printf("| %ld | Error Code 0x%08x | Error Code %d.%d | Error ID %s_%s | Error Description: '%s' |\n", i, error_code, context,
           subcode, error_code_to_context_str(error_code),
           error_code_to_subcode_name_str(error_code),
           error_code_to_subcode_description_str(error_code));
  }
}

/*

# Context Code List
| context number: 0 | context name: C1 | context description: 'Error Context Description 1' |
| context number: 1 | context name: C2 | context description: 'Error Context Description 2' |

# Error Code List
| 0 | Error Code 0x00000000 | Error Code 0.0 | Error ID C1_T1 | Error Description: 'Error Description C1T1' |
| 1 | Error Code 0x00000001 | Error Code 0.1 | Error ID C1_T2 | Error Description: 'Error Description C1T2' |
| 2 | Error Code 0x00000002 | Error Code 0.2 | Error ID C1_T3 | Error Description: 'Error Description C1T3' |
| 3 | Error Code 0x00010000 | Error Code 1.0 | Error ID C2_T1 | Error Description: 'Error Description C2T1' |
| 4 | Error Code 0x00010001 | Error Code 1.1 | Error ID C2_T2 | Error Description: 'Error Description C2T2' |
| 5 | Error Code 0x00010002 | Error Code 1.2 | Error ID C2_T3 | Error Description: 'Error Description C2T3' |
*/