maint/gnulib/lib/unistr/u8-strrchr.c

/* */
This source file includes following definitions.
u8_strrchr
   1 /* Search character in UTF-8 string.
   2    Copyright (C) 1999, 2002, 2006-2007, 2009-2021 Free Software Foundation,
   3    Inc.
   4    Written by Bruno Haible <bruno@clisp.org>, 2002.
   5 
   6    This file is free software.
   7    It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
   8    You can redistribute it and/or modify it under either
   9      - the terms of the GNU Lesser General Public License as published
  10        by the Free Software Foundation; either version 3, or (at your
  11        option) any later version, or
  12      - the terms of the GNU General Public License as published by the
  13        Free Software Foundation; either version 2, or (at your option)
  14        any later version, or
  15      - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
  16 
  17    This file is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20    Lesser General Public License and the GNU General Public License
  21    for more details.
  22 
  23    You should have received a copy of the GNU Lesser General Public
  24    License and of the GNU General Public License along with this
  25    program.  If not, see <https://www.gnu.org/licenses/>.  */
  26 
  27 #include <config.h>
  28 
  29 /* Specification.  */
  30 #include "unistr.h"
  31 
  32 uint8_t *
  33 u8_strrchr (const uint8_t *s, ucs4_t uc)
     /*  */
  34 {
  35   /* Calling u8_strlen and then searching from the other end would cause more
  36      memory accesses. Avoid that, at the cost of a few more comparisons.  */
  37   uint8_t *result = NULL;
  38   uint8_t c[6];
  39 
  40   if (uc < 0x80)
  41     {
  42       uint8_t c0 = uc;
  43 
  44       for (;; s++)
  45         {
  46           if (*s == c0)
  47             result = (uint8_t *) s;
  48           if (*s == 0)
  49             break;
  50         }
  51     }
  52   else
  53     switch (u8_uctomb_aux (c, uc, 6))
  54       {
  55       case 2:
  56         if (*s)
  57           {
  58             uint8_t c0 = c[0];
  59             uint8_t c1 = c[1];
  60 
  61             /* FIXME: Maybe walking the string via u8_mblen is a win?  */
  62             for (;; s++)
  63               {
  64                 if (s[1] == 0)
  65                   break;
  66                 if (*s == c0 && s[1] == c1)
  67                   result = (uint8_t *) s;
  68               }
  69           }
  70         break;
  71 
  72       case 3:
  73         if (*s && s[1])
  74           {
  75             uint8_t c0 = c[0];
  76             uint8_t c1 = c[1];
  77             uint8_t c2 = c[2];
  78 
  79             /* FIXME: Maybe walking the string via u8_mblen is a win?  */
  80             for (;; s++)
  81               {
  82                 if (s[2] == 0)
  83                   break;
  84                 if (*s == c0 && s[1] == c1 && s[2] == c2)
  85                   result = (uint8_t *) s;
  86               }
  87           }
  88         break;
  89 
  90       case 4:
  91         if (*s && s[1] && s[2])
  92           {
  93             uint8_t c0 = c[0];
  94             uint8_t c1 = c[1];
  95             uint8_t c2 = c[2];
  96             uint8_t c3 = c[3];
  97 
  98             /* FIXME: Maybe walking the string via u8_mblen is a win?  */
  99             for (;; s++)
 100               {
 101                 if (s[3] == 0)
 102                   break;
 103                 if (*s == c0 && s[1] == c1 && s[2] == c2 && s[3] == c3)
 104                   result = (uint8_t *) s;
 105               }
 106           }
 107         break;
 108       }
 109   return result;
 110 }
/* */
root/maint/gnulib/lib/unistr/u8-strrchr.c

DEFINITIONS
