1 /*
   2  * Copyright (c) 1997, 2004, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 # include "incls/_precompiled.incl"
  26 # include "incls/_utf8.cpp.incl"
  27 
  28 // Assume the utf8 string is in legal form and has been
  29 // checked in the class file parser/format checker.
  30 char* UTF8::next(const char* str, jchar* value) {
  31   unsigned const char *ptr = (const unsigned char *)str;
  32   unsigned char ch, ch2, ch3;
  33   int length = -1;              /* bad length */
  34   jchar result;
  35   switch ((ch = ptr[0]) >> 4) {
  36     default:
  37     result = ch;
  38     length = 1;
  39     break;
  40 
  41   case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:
  42     /* Shouldn't happen. */
  43     break;
  44 
  45   case 0xC: case 0xD:
  46     /* 110xxxxx  10xxxxxx */
  47     if (((ch2 = ptr[1]) & 0xC0) == 0x80) {
  48       unsigned char high_five = ch & 0x1F;
  49       unsigned char low_six = ch2 & 0x3F;
  50       result = (high_five << 6) + low_six;
  51       length = 2;
  52       break;
  53     }
  54     break;
  55 
  56   case 0xE:
  57     /* 1110xxxx 10xxxxxx 10xxxxxx */
  58     if (((ch2 = ptr[1]) & 0xC0) == 0x80) {
  59       if (((ch3 = ptr[2]) & 0xC0) == 0x80) {
  60         unsigned char high_four = ch & 0x0f;
  61         unsigned char mid_six = ch2 & 0x3f;
  62         unsigned char low_six = ch3 & 0x3f;
  63         result = (((high_four << 6) + mid_six) << 6) + low_six;
  64         length = 3;
  65       }
  66     }
  67     break;
  68   } /* end of switch */
  69 
  70   if (length <= 0) {
  71     *value = ptr[0];    /* default bad result; */
  72     return (char*)(ptr + 1); // make progress somehow
  73   }
  74 
  75   *value = result;
  76 
  77   // The assert is correct but the .class file is wrong
  78   // assert(UNICODE::utf8_size(result) == length, "checking reverse computation");
  79   return (char *)(ptr + length);
  80 }
  81 
  82 char* UTF8::next_character(const char* str, jint* value) {
  83   unsigned const char *ptr = (const unsigned char *)str;
  84   /* See if it's legal supplementary character:
  85      11101101 1010xxxx 10xxxxxx 11101101 1011xxxx 10xxxxxx */
  86   if (is_supplementary_character(ptr)) {
  87     *value = get_supplementary_character(ptr);
  88     return (char *)(ptr + 6);
  89   }
  90   jchar result;
  91   char* next_ch = next(str, &result);
  92   *value = result;
  93   return next_ch;
  94 }
  95 
  96 // Count bytes of the form 10xxxxxx and deduct this count
  97 // from the total byte count.  The utf8 string must be in
  98 // legal form which has been verified in the format checker.
  99 int UTF8::unicode_length(const char* str, int len) {
 100   int num_chars = len;
 101   for (int i = 0; i < len; i++) {
 102     if ((str[i] & 0xC0) == 0x80) {
 103       --num_chars;
 104     }
 105   }
 106   return num_chars;
 107 }
 108 
 109 // Count bytes of the utf8 string except those in form
 110 // 10xxxxxx which only appear in multibyte characters.
 111 // The utf8 string must be in legal form and has been
 112 // verified in the format checker.
 113 int UTF8::unicode_length(const char* str) {
 114   int num_chars = 0;
 115   for (const char* p = str; *p; p++) {
 116     if (((*p) & 0xC0) != 0x80) {
 117       num_chars++;
 118     }
 119   }
 120   return num_chars;
 121 }
 122 
 123 // Writes a jchar a utf8 and returns the end
 124 static u_char* utf8_write(u_char* base, jchar ch) {
 125   if ((ch != 0) && (ch <=0x7f)) {
 126     base[0] = (u_char) ch;
 127     return base + 1;
 128   }
 129 
 130   if (ch <= 0x7FF) {
 131     /* 11 bits or less. */
 132     unsigned char high_five = ch >> 6;
 133     unsigned char low_six = ch & 0x3F;
 134     base[0] = high_five | 0xC0; /* 110xxxxx */
 135     base[1] = low_six | 0x80;   /* 10xxxxxx */
 136     return base + 2;
 137   }
 138   /* possibly full 16 bits. */
 139   char high_four = ch >> 12;
 140   char mid_six = (ch >> 6) & 0x3F;
 141   char low_six = ch & 0x3f;
 142   base[0] = high_four | 0xE0; /* 1110xxxx */
 143   base[1] = mid_six | 0x80;   /* 10xxxxxx */
 144   base[2] = low_six | 0x80;   /* 10xxxxxx */
 145   return base + 3;
 146 }
 147 
 148 void UTF8::convert_to_unicode(const char* utf8_str, jchar* unicode_str, int unicode_length) {
 149   unsigned char ch;
 150   const char *ptr = (const char *)utf8_str;
 151   int index = 0;
 152 
 153   /* ASCII case loop optimization */
 154   for (; index < unicode_length; index++) {
 155     if((ch = ptr[0]) > 0x7F) { break; }
 156     unicode_str[index] = ch;
 157     ptr = (const char *)(ptr + 1);
 158   }
 159 
 160   for (; index < unicode_length; index++) {
 161     ptr = UTF8::next(ptr, &unicode_str[index]);
 162   }
 163 }
 164 
 165 // Returns NULL if 'c' it not found. This only works as long
 166 // as 'c' is an ASCII character
 167 jbyte* UTF8::strrchr(jbyte* base, int length, jbyte c) {
 168   assert(length >= 0, "sanity check");
 169   assert(c >= 0, "does not work for non-ASCII characters");
 170   // Skip backwards in string until 'c' is found or end is reached
 171   while(--length >= 0 && base[length] != c);
 172   return (length < 0) ? NULL : &base[length];
 173 }
 174 
 175 bool UTF8::equal(jbyte* base1, int length1, jbyte* base2, int length2) {
 176   // Length must be the same
 177   if (length1 != length2) return false;
 178   for (int i = 0; i < length1; i++) {
 179     if (base1[i] != base2[i]) return false;
 180   }
 181   return true;
 182 }
 183 
 184 bool UTF8::is_supplementary_character(const unsigned char* str) {
 185   return ((str[0] & 0xFF) == 0xED) && ((str[1] & 0xF0) == 0xA0) && ((str[2] & 0xC0) == 0x80)
 186       && ((str[3] & 0xFF) == 0xED) && ((str[4] & 0xF0) == 0xB0) && ((str[5] & 0xC0) == 0x80);
 187 }
 188 
 189 jint UTF8::get_supplementary_character(const unsigned char* str) {
 190   return 0x10000 + ((str[1] & 0x0f) << 16) + ((str[2] & 0x3f) << 10)
 191                  + ((str[4] & 0x0f) << 6)  + (str[5] & 0x3f);
 192 }
 193 
 194 
 195 //-------------------------------------------------------------------------------------
 196 
 197 
 198 int UNICODE::utf8_size(jchar c) {
 199   if ((0x0001 <= c) && (c <= 0x007F)) return 1;
 200   if (c <= 0x07FF) return 2;
 201   return 3;
 202 }
 203 
 204 int UNICODE::utf8_length(jchar* base, int length) {
 205   int result = 0;
 206   for (int index = 0; index < length; index++) {
 207     jchar c = base[index];
 208     if ((0x0001 <= c) && (c <= 0x007F)) result += 1;
 209     else if (c <= 0x07FF) result += 2;
 210     else result += 3;
 211   }
 212   return result;
 213 }
 214 
 215 char* UNICODE::as_utf8(jchar* base, int length) {
 216   int utf8_len = utf8_length(base, length);
 217   u_char* result = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);
 218   u_char* p = result;
 219   for (int index = 0; index < length; index++) {
 220     p = utf8_write(p, base[index]);
 221   }
 222   *p = '\0';
 223   assert(p == &result[utf8_len], "length prediction must be correct");
 224   return (char*) result;
 225 }
 226 
 227 char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {
 228   u_char* p = (u_char*)buf;
 229   u_char* end = (u_char*)buf + buflen;
 230   for (int index = 0; index < length; index++) {
 231     jchar c = base[index];
 232     if (p + utf8_size(c) >= end) break;      // string is truncated
 233     p = utf8_write(p, base[index]);
 234   }
 235   *p = '\0';
 236   return buf;
 237 }
 238 
 239 void UNICODE::convert_to_utf8(const jchar* base, int length, char* utf8_buffer) {
 240   for(int index = 0; index < length; index++) {
 241     utf8_buffer = (char*)utf8_write((u_char*)utf8_buffer, base[index]);
 242   }
 243   *utf8_buffer = '\0';
 244 }