/* -*- c -*- */
/**
* libgamma -- Display server abstraction layer for gamma ramp adjustments
* Copyright (C) 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "libgamma-error.h"
#include <stddef.h>
#include <sys/types.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
$>set -u
$>cd src/extract
$>export PATH=".:${PATH}"
/**
* Group that the user needs to be a member of if
* `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned.
*/
#ifndef __WIN32__
gid_t libgamma_group_gid = 0;
#else
short libgamma_group_gid = 0;
#endif
/**
* Group that the user needs to be a member of if
* `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned,
* `NULL` if the name of the group `libgamma_group_gid`
* cannot be determined.
*/
const char* libgamma_group_name = NULL;
/**
* Prints an error to stderr in a `perror` fashion,
* however this function will not translate the `libgamma`
* errors into human-readable strings, it will simply
* print the name of the error. If the value `error_code`
* is the value of `LIBGAMMA_ERRNO_SET`, `perror` will be
* used to print the current error stored in `errno`.
* If `error_code` is non-negative (an `errno` value`), that
* value will be stored in `errno` and `perror` will be
* used to print it. Additionally, if the `error_code` is
* the value of `LIBGAMMA_DEVICE_REQUIRE_GROUP` the
* required group will be printed with its numerical value
* and, if known, its name.
*
* @param name The text to add at the beginning.
* @param value The error code, may be an `errno` value.
*/
void libgamma_perror(const char* name, int error_code)
{
if (error_code >= 0)
{
/* Print the stored errno value. */
errno = error_code;
perror(name);
}
else if (error_code == LIBGAMMA_ERRNO_SET)
/* Print errno. */
perror(name);
else if (error_code == LIBGAMMA_DEVICE_REQUIRE_GROUP)
{
/* Print the error name and the required group membership. */
const char* error = libgamma_name_of_error(error_code);
long int gid = (long int)libgamma_group_gid;
if (libgamma_group_name == NULL)
/* Group name unknown. */
fprintf(stderr, "%s: %s: %ld\n", name, error, gid);
else
/* Group name known, ID is second class. */
fprintf(stderr, "%s: %s: %s (%ld)\n", name, error, libgamma_group_name, gid);
}
else if (error_code < LIBGAMMA_ERROR_MIN)
/* If the error code does not exist, print "(?)" */
fprintf(stderr, "%s: (?)\n", name);
else
/* Print the name of the error. */
fprintf(stderr, "%s: %s\n", name, libgamma_name_of_error(error_code));
}
/**
* Returns the name of the definition associated with a `libgamma` error code.
*
* @param value The error code.
* @return The name of the definition associated with the error code,
* `NULL` if the error code does not exist. The return string
* should not be `free`:d.
*/
const char* libgamma_name_of_error(int value)
{
/* Map from error codes to error names.
The output of $(libgamma-error-extract --list)
is sorted by error code in decreasing order. */
static const char* error_names[] =
{
$>for error in $(libgamma-error-extract --list); do
"${error}",
$>done
};
/* Return `NULL` if the error code is invalid. */
if ((value < LIBGAMMA_ERROR_MIN) || (value >= 0))
return NULL;
/* Convert error code from {-1, -2, -3, ...} to {0, 1, 2, ...}
and look up the error's name and return it. */
return error_names[-value - 1];
}
/**
* Return the value of a `libgamma` error definition refered to by name.
*
* @param name The name of the definition associated with the error code.
* @return The error code, zero if the name does is `NULL`
* or does not refer to a `libgamma` error.
*/
int libgamma_value_of_error(const char* name)
{
/* Return 0 (not a valid error code) if the error name is `NULL`. */
if (name == NULL)
return 0;
/* Test error names against `name` and return the value of the match error. */
$>for error in $(libgamma-error-extract --list); do
if (!strcmp(name, "${error}")) return ${error};
$>done
/* Return 0 (not a valid error code) if the error name is unknown. */
return 0;
}
