glibc/time/alt_digit.c

182 lines
4.5 KiB
C

/* Helper functions used by strftime/strptime to handle alternate digits.
Copyright (C) 1995-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include "../locale/localeinfo.h"
#include <libc-lock.h>
#include <stdlib.h>
#include <wchar.h>
#include <string.h>
#include <stdint.h>
/* Some of the functions here must not be used while setlocale is called. */
__libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)
#define CURRENT(item) (current->values[_NL_ITEM_INDEX (item)].string)
#define CURRENT_WSTR(item) \
((wchar_t *) current->values[_NL_ITEM_INDEX (item)].wstr)
static struct lc_time_data *
_nl_init_alt_digit (struct __locale_data *current)
{
struct lc_time_data *data = current->private;
if (data == NULL)
{
data = calloc (sizeof *data, 1);
if (data == NULL)
return NULL;
current->private = data;
}
if (! data->alt_digits_initialized)
{
const char *ptr = CURRENT (ALT_DIGITS);
size_t cnt;
data->alt_digits_initialized = 1;
if (ptr != NULL)
{
data->alt_digits = malloc (100 * sizeof (const char *));
if (data->alt_digits != NULL)
for (cnt = 0; cnt < 100; ++cnt)
{
data->alt_digits[cnt] = ptr;
/* Skip digit format. */
ptr = strchr (ptr, '\0') + 1;
}
}
}
return data;
}
const char *
_nl_get_alt_digit (unsigned int number, struct __locale_data *current)
{
const char *result;
if (number >= 100 || CURRENT (ALT_DIGITS)[0] == '\0')
return NULL;
__libc_rwlock_wrlock (__libc_setlocale_lock);
struct lc_time_data *data = _nl_init_alt_digit (current);
result = ((data != NULL
&& data->alt_digits != NULL)
? data->alt_digits[number]
: NULL);
__libc_rwlock_unlock (__libc_setlocale_lock);
return result;
}
const wchar_t *
_nl_get_walt_digit (unsigned int number, struct __locale_data *current)
{
const wchar_t *result = NULL;
if (number >= 100 || CURRENT_WSTR (_NL_WALT_DIGITS)[0] == L'\0')
return NULL;
__libc_rwlock_wrlock (__libc_setlocale_lock);
struct lc_time_data *data = current->private;
if (data == NULL)
{
data = calloc (sizeof *data, 1);
if (data == NULL)
goto out;
current->private = data;
}
if (! data->walt_digits_initialized)
{
const wchar_t *ptr = CURRENT_WSTR (_NL_WALT_DIGITS);
size_t cnt;
data->walt_digits_initialized = 1;
if (ptr != NULL)
{
data->walt_digits = malloc (100 * sizeof (const uint32_t *));
if (data->walt_digits != NULL)
for (cnt = 0; cnt < 100; ++cnt)
{
data->walt_digits[cnt] = ptr;
/* Skip digit format. */
ptr = __wcschr (ptr, L'\0') + 1;
}
}
}
if (data->walt_digits != NULL)
result = data->walt_digits[number];
out:
__libc_rwlock_unlock (__libc_setlocale_lock);
return (wchar_t *) result;
}
int
_nl_parse_alt_digit (const char **strp, struct __locale_data *current)
{
const char *str = *strp;
int result = -1;
size_t cnt;
size_t maxlen = 0;
if (CURRENT_WSTR (_NL_WALT_DIGITS)[0] == L'\0')
return result;
__libc_rwlock_wrlock (__libc_setlocale_lock);
struct lc_time_data *data = _nl_init_alt_digit (current);
if (data != NULL && data->alt_digits != NULL)
/* Matching is not unambiguous. The alternative digits could be like
I, II, III, ... and the first one is a substring of the second
and third. Therefore we must keep on searching until we found
the longest possible match. Note that this is not specified in
the standard. */
for (cnt = 0; cnt < 100; ++cnt)
{
const char *const dig = data->alt_digits[cnt];
size_t len = strlen (dig);
if (len > maxlen && strncmp (dig, str, len) == 0)
{
maxlen = len;
result = (int) cnt;
}
}
__libc_rwlock_unlock (__libc_setlocale_lock);
if (result != -1)
*strp += maxlen;
return result;
}