third_party/ulib/musl/src/locale/locale_map.c

#include "locale_impl.h"
#include <locale.h>
#include <string.h>
#include <threads.h>

const char* __lctrans(const char* msg, const struct __locale_map* lm) {
    const char* trans = 0;
    if (lm)
        trans = __mo_lookup(lm->map, lm->map_size, msg);
    return trans ? trans : msg;
}

const unsigned char* __map_file(const char*, size_t*);
int __munmap(void*, size_t);
char* __strchrnul(const char*, int);

static const char envvars[][12] = {
    "LC_CTYPE", "LC_NUMERIC", "LC_TIME", "LC_COLLATE", "LC_MONETARY", "LC_MESSAGES",
};

const struct __locale_map* __get_locale(int cat, const char* val) {
    static mtx_t lock;
    static void* volatile loc_head;
    const struct __locale_map* p;
    struct __locale_map* new = 0;
    const char* z;
    char buf[256];
    size_t l, n;

    if (!*val) {
        ((val = getenv("LC_ALL")) && *val) || ((val = getenv(envvars[cat])) && *val) ||
            ((val = getenv("LANG")) && *val) || (val = "C.UTF-8");
    }

    /* Limit name length and forbid leading dot or any slashes. */
    for (n = 0; n < LOCALE_NAME_MAX && val[n] && val[n] != '/'; n++)
        ;
    if (val[0] == '.' || val[n])
        val = "C.UTF-8";
    int builtin = (val[0] == 'C' && !val[1]) || !strcmp(val, "C.UTF-8") || !strcmp(val, "POSIX");

    if (builtin) {
        if (cat == LC_CTYPE && val[1] == '.')
            return (void*)&__c_dot_utf8;
        return 0;
    }

    for (p = loc_head; p; p = p->next)
        if (!strcmp(val, p->name))
            return p;

    mtx_lock(&lock);

    for (p = loc_head; p; p = p->next)
        if (!strcmp(val, p->name)) {
            mtx_unlock(&lock);
            return p;
        }

    const char* path = getenv("MUSL_LOCPATH");
    /* FIXME: add a default path? */

    if (path)
        for (; *path; path = z + !!*z) {
            z = __strchrnul(path, ':');
            l = z - path - !!*z;
            if (l >= sizeof buf - n - 2)
                continue;
            memcpy(buf, path, l);
            buf[l] = '/';
            memcpy(buf + l + 1, val, n);
            buf[l + 1 + n] = 0;
            size_t map_size;
            const void* map = __map_file(buf, &map_size);
            if (map) {
                new = malloc(sizeof *new);
                if (!new) {
                    __munmap((void*)map, map_size);
                    break;
                }
                new->map = map;
                new->map_size = map_size;
                memcpy(new->name, val, n);
                new->name[n] = 0;
                new->next = loc_head;
                loc_head = new;
                break;
            }
        }

    /* If no locale definition was found, make a locale map
     * object anyway to store the name, which is kept for the
     * sake of being able to do message translations at the
     * application level. */
    if (!new && (new = malloc(sizeof *new))) {
        new->map = __c_dot_utf8.map;
        new->map_size = __c_dot_utf8.map_size;
        memcpy(new->name, val, n);
        new->name[n] = 0;
        new->next = loc_head;
        loc_head = new;
    }

    /* For LC_CTYPE, never return a null pointer unless the
     * requested name was "C" or "POSIX". */
    if (!new&& cat == LC_CTYPE)
        new = (void*)&__c_dot_utf8;

    mtx_unlock(&lock);
    return new;
}