/* See LICENSE file for copyright and license details. */
#ifndef LIBERROR_H
#define LIBERROR_H
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
/**
* Opaque backtrace structure
*/
struct liberror_backtrace;
/**
* Value that specifies which feild in a
* `union liberror_details` that is used
*/
enum liberror_details_type {
/**
* No details
*/
LIBERROR_DETAILS_NONE,
/**
* User-specific details
*/
LIBERROR_DETAILS_USER,
/**
* Details for function that operates
* on a single file
*/
LIBERROR_DETAILS_ONE_FILE,
/**
* Details for function that operates
* on two files
*/
LIBERROR_DETAILS_TWO_FILES
};
/**
* Error details
*/
union liberror_details {
/**
* For `LIBERROR_DETAILS_USER`
*/
struct {
/**
* The library that defines the data
*/
const char *library;
/**
* The data for the details
*/
void *data;
/**
* Function that is used to deallocate `.data`
*
* @param data The pointer `.data`
*/
void (*free_data)(void *);
/**
* Function that is used to copy `.data`
*
* @param data The pointer `.data`
* @return Copy of `data`, `NULL` on failure
*/
void *(*copy_data)(void *);
/**
* Function that is used to print `.data`
*
* @param data The pointer `.data`, may be `NULL`
* @param fp File to print the details to, may not be `NULL`
* @param prefix Text to print at the beginning of each line,
* may not be `NULL`
*/
void (*print_data)(void *, FILE *, const char *);
} user;
/**
* For `LIBERROR_DETAILS_ONE_FILE`
*/
struct {
/**
* The specified file descriptor,
* negative if none
*/
int fd;
/**
* The filename or other string that
* identifies the file, `NULL` if
* none
*/
char *name;
/**
* Description of the file's role in the
* function call, for example "Directory"
* for the mkdir(3) function
*/
const char *role;
} one_file;
/**
* For `LIBERROR_DETAILS_TWO_FILES`
*/
struct {
/**
* The first specified file descriptor,
* negative if none
*/
int fd1;
/**
* The second specified file descriptor,
* negative if none
*/
int fd2;
/**
* The filename or other string that
* identifies the first file, `NULL` if
* none
*/
char *name1;
/**
* The filename or other string that
* identifies the second file, `NULL`
* if none
*/
char *name2;
/**
* Description of the role of the first
* file in the function call, for example
* "Target" for the symlink(3) function
*/
const char *role1;
/**
* Description of the role of the first
* file in the function call, for example
* "Link" for the symlink(3) function
*/
const char *role2;
} two_files;
};
/**
* Error structure
*/
struct liberror_error {
/**
* Backtrace for the error, `NULL` if the it could
* not be allocated or if the program is not linked
* with `-lerror-backtrace`
*/
struct liberror_backtrace *backtrace;
/**
* Description of the error
*/
char description[256];
/**
* The function that failed
*/
char source[64];
/**
* Name of error code group, for normal `errno`
* errors this is "error", for getaddrinfo(3) errors
* this is "addrinfo", for custom errors it is the
* name of the library or application
*/
char code_group[64];
/**
* The error code
*/
long long int code;
/**
* The error that caused this error, `NULL` if
* none or it could not be allocated (if and only
* if so, `.failed_to_allocate_cause` will be set
* to a non-zero value, specifically 1)
*/
struct liberror_error *cause;
/**
* Whether allocation of `.cause` failed
*/
int failed_to_allocate_cause;
/**
* Whether the error is physically allocated
*/
int dynamically_allocated;
/**
* Which value in `.details` that is used
*/
enum liberror_details_type details_type;
/**
* Error detail
*/
union liberror_details details;
};
/**
* Saved error state for a thread
*
* This structure shall be regardes as opaque
*/
struct liberror_state {
/**
* The backtrace for the next error
*/
struct liberror_backtrace *backtrace;
/**
* The thread's error
*/
struct liberror_error error;
/**
* Whether the thread hade an error
*/
int have_error;
/**
* The thread's value of `errno`
*/
int errnum;
};
/**
* Get the current error for the thread
*
* @return The current error, `NULL` if none
*/
struct liberror_error *liberror_get_error(void);
/**
* Create a copy of an error
*
* This function will only fail of enough memory
* cannot be allocated, however `errno` will not
* be changed
*
* @param error The error to copy
* @return Copy of the error, `NULL` on failure
*/
struct liberror_error *liberror_copy_error(struct liberror_error *);
/**
* Deallocate the error and the error stored as
* its cause (recursively)
*
* @param error The error to deallocate
*/
void liberror_free_error(struct liberror_error *);
/**
* Deallocate the current error for the thread
* and reset the error for the thread
*
* This function shall be called after handling
* the error
*/
void liberror_reset_error(void);
/**
* Print the backtrace of an error
*
* If the backtrace could not be allocated,
* nothing will be printed
*
* This function will never change `errno`
*
* Note: this library does not actually save
* a backtrace, `-lerror-backtrace` is needed
* for that functionallity (it will replace
* some things in this library, so no other
* action is required)
*
* @param error The error
* @param fp The file to print the backtrace to
* @param indent Text to print at the beginning of each line
*/
void liberror_print_backtrace(struct liberror_error *, FILE *, const char *);
/**
* Get backtrace and save backtrace
*
* This function will never change `errno`
*
* Note: this library does not actually save
* a backtrace, `-lerror-backtrace` is needed
* for that functionallity (it will replace
* some things in this library, so no other
* action is required)
*
* @param error The error the backtrace shall be stored in,
* if `NULL`, the backtrafe is saved for the
* next error in the thread
* @return 0 on success, -1 on failure
*/
int liberror_save_backtrace(struct liberror_error *);
/**
* Set the current error for the thread
*
* If the thread already has an error saved,
* it will be stored as the cause of the new
* error
*
* @param description Description of the error, empty for default description
* @param source The function that failed
* @param code_group Name of error code group, for normal `errno` errors
* this shall be "error", for getaddrinfo(3) errors
* this shall be "addrinfo", for custom errors it shall
* be the name of the library or application
* @param code The error code
*/
void liberror_set_error(const char[256], const char[64], const char[64], long long int);
/**
* Set the current error for the thread
*
* This function can be used as an alternative
* to `liberror_set_error` for `errno` errors
*
* If the thread already has an error saved,
* it will be stored as the cause of the new
* error
*
* @param description Description of the error, empty for default description
* @param source The function that failed
* @param code The `errno` value
*/
void liberror_set_error_errno(const char[256], const char[64], int);
/**
* The an error, its backtrace, and its
* cause (recursively)
*
* If `error` is `NULL` and the thread does
* not have any error set, this function
* will not do anything
*
* @param error The error, the thread's current error if `NULL`
* @param fp Output stream, standard error if `NULL`
* @param reset Whether `error` shall be deallocated, `error`
* is null and `reset` is non-zero, the thread's
* error will be reset
* @param prefix Prefix for each printed line, ": " will be
* appended to this prefix; if `NULL` or empty,
* no prefix is used; this should normally be
* `argv[0]` from the main() function
*/
void liberror_print_error(struct liberror_error *, FILE *, int, const char *);
/**
* Save the thread's liberror error, pending backtrace,
* and `errno`, and then reset the error information
* for the thread
*
* Asynchronously called functions such as signal handlers
* should call this function the first thing they do
*
* @param state Output parameter for the error state
*/
void liberror_start(struct liberror_state *);
/**
* Restore the thread's liberror error, pending backtrace,
* and `errno`
*
* Asynchronously called functions such as signal handlers
* should call this function the last thing they do before
* returning
*
* @param state The saved error state to restore
*/
void liberror_end(const struct liberror_state *);
#endif
