#ifndef ERROR_H
#define ERROR_H
/*
* Error-handling functions
*/
#include <errno.h>
/*
* Type used for error codes is an explicitly *unsigned* int, meaning that error codes themselves are positive.
* Negative error codes also exist in some places, and they are just a negative err_t.
*/
typedef unsigned int err_t;
/*
* List of defined error codes, organized mostly by function name
*/
enum error_code {
ERR_CALLOC = 0x000100,
// network resolver errors
ERR_GETADDRINFO = 0x000200,
ERR_GETADDRINFO_EMPTY = 0x000201, /* No valid results */
// low-level network errors
ERR_SOCKET = 0x000301,
ERR_CONNECT = 0x000302,
// low-level IO errors
ERR_READ = 0x000401,
ERR_WRITE = 0x000402,
};
/*
* An error code and associated extra infos
*/
struct error_info {
/* The base error code */
err_t code;
/* Additional detail info, usually some third-part error code */
unsigned int extra;
};
/** No error, evaulates as logical false */
#define SUCCESS (0)
/* Evaulates to error_info.code as lvalue */
#define ERROR_CODE(err_info) ((err_info).code)
/* Evaulates to error_info.extra as lvalue */
#define ERROR_EXTRA(err_info) ((err_info).extra)
/* Set error_info.code to SUCCESS, evaulates as zero */
#define RESET_ERROR(err_info) ((err_info).code = SUCCESS)
/* Compare error_info.code != 0 */
#define IS_ERROR(err_info) (!!(err_info).code)
/* Set error_info.code, but leave err_extra as-is. Evaluates to err_code */
#define SET_ERROR(err_info, err_code) ((err_info).code = (err_code))
/* Set error_info.code/extra. XXX: should evaluate to err_code */
#define _SET_ERROR_EXTRA(err_info, err_code, err_extra) (err_info).code = (err_code); err_info.extra = (err_extra)
#define SET_ERROR_EXTRA(err_info, err_code, err_extra) do { _SET_ERROR_EXTRA(err_info, err_code, err_extra); } while (0)
/* Set error.info.code to err_code, and .extra to errno. XXX: should evaulate to err_code */
#define _SET_ERROR_ERRNO(err_info, err_code) _SET_ERROR_EXTRA(err_info, err_code, errno);
#define SET_ERROR_ERRNO(err_info, err_code) SET_ERROR_EXTRA(err_info, err_code, errno);
/* Ss above, but also return err_code from func. XXX: use 'return SET_ERROR...' instead */
#define RETURN_SET_ERROR(err_info, err_code) do { _SET_ERROR(err_info, err_code); return (err_code); } while (0)
#define RETURN_SET_ERROR_EXTRA(err_info, err_code, err_extra) do { _SET_ERROR_EXTRA(err_info, err_code, err_extra); return (err_code); } while (0)
#define RETURN_SET_ERROR_ERRNO(err_info, err_code) do { _SET_ERROR_ERRNO(err_info, err_code); return (err_code); } while (0)
#endif