usr/src/lib/libc/port/locale/strcoll.c

   1 /*
   2  * Copyright 2013 Garrett D'Amore <garrett@damore.org>
   3  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
   4  * Copyright (c) 1995 Alex Tatmanjants <alex@elvisti.kiev.ua>
   5  *              at Electronni Visti IA, Kiev, Ukraine.
   6  *                      All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include "lint.h"
  31 #include "file64.h"
  32 #include <alloca.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <errno.h>
  36 #include <wchar.h>
  37 #include <xlocale.h>
  38 #include "localeimpl.h"
  39 #include "collate.h"
  40
  41 #define ALLOCA_LIMIT    16
  42
  43 /*
  44  * In order to properly handle multibyte locales, its easiet to just
  45  * convert to wide characters and then use wcscoll.  However if an
  46  * error occurs, we gracefully fall back to simple strcmp.  Caller
  47  * should check errno.
  48  */
  49 int
  50 strcoll_l(const char *s1, const char *s2, locale_t loc)
  51 {
  52         int ret;
  53         wchar_t *t1 = NULL, *t2 = NULL;
  54         wchar_t *w1 = NULL, *w2 = NULL;
  55         size_t sz1, sz2;
  56         const struct lc_collate *lcc = loc->collate;
  57
  58         if (lcc->lc_is_posix)
  59                 return (strcmp(s1, s2));
  60
  61         sz1 = strlen(s1) + 1;
  62         sz2 = strlen(s2) + 1;
  63
  64         /*
  65          * Simple assumption: conversion to wide format is strictly
  66          * reducing, i.e. a single byte (or multibyte character)
  67          * cannot result in multiple wide characters.
  68          *
  69          * We gain a bit of performance by giving preference to alloca
  70          * for small string allocations.
  71          */
  72         if (sz1 > ALLOCA_LIMIT) {
  73                 if ((t1 = malloc(sz1 * sizeof (wchar_t))) == NULL)
  74                         goto error;
  75                 w1 = t1;
  76         } else {
  77                 if ((w1 = alloca(sz1 * sizeof (wchar_t))) == NULL)
  78                         goto error;
  79         }
  80         if (sz2 > ALLOCA_LIMIT) {
  81                 if ((t2 = malloc(sz2 * sizeof (wchar_t))) == NULL)
  82                         goto error;
  83                 w2 = t2;
  84         } else {
  85                 if ((w2 = alloca(sz2 * sizeof (wchar_t))) == NULL)
  86                         goto error;
  87         }
  88
  89         if ((mbstowcs_l(w1, s1, sz1, loc)) == (size_t)-1)
  90                 goto error;
  91
  92         if ((mbstowcs_l(w2, s2, sz2, loc)) == (size_t)-1)
  93                 goto error;
  94
  95         ret = wcscoll_l(w1, w2, loc);
  96         if (t1)
  97                 free(t1);
  98         if (t2)
  99                 free(t2);
 100
 101         return (ret);
 102
 103 error:
 104         if (t1)
 105                 free(t1);
 106         if (t2)
 107                 free(t2);
 108         return (strcmp(s1, s2));
 109 }
 110
 111 int
 112 strcoll(const char *s1, const char *s2)
 113 {
 114         return (strcoll_l(s1, s2, uselocale(NULL)));
 115 }