1/* 2 * This is an implementation of wcwidth() and wcswidth() (defined in 3 * IEEE Std 1002.1-2001) for Unicode. 4 * 5 * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html 6 * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html 7 * 8 * In fixed-width output devices, Latin characters all occupy a single 9 * "cell" position of equal width, whereas ideographic CJK characters 10 * occupy two such cells. Interoperability between terminal-line 11 * applications and (teletype-style) character terminals using the 12 * UTF-8 encoding requires agreement on which character should advance 13 * the cursor by how many cell positions. No established formal 14 * standards exist at present on which Unicode character shall occupy 15 * how many cell positions on character terminals. These routines are 16 * a first attempt of defining such behavior based on simple rules 17 * applied to data provided by the Unicode Consortium. 18 * 19 * For some graphical characters, the Unicode standard explicitly 20 * defines a character-cell width via the definition of the East Asian 21 * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes. 22 * In all these cases, there is no ambiguity about which width a 23 * terminal shall use. For characters in the East Asian Ambiguous (A) 24 * class, the width choice depends purely on a preference of backward 25 * compatibility with either historic CJK or Western practice. 26 * Choosing single-width for these characters is easy to justify as 27 * the appropriate long-term solution, as the CJK practice of 28 * displaying these characters as double-width comes from historic 29 * implementation simplicity (8-bit encoded characters were displayed 30 * single-width and 16-bit ones double-width, even for Greek, 31 * Cyrillic, etc.) and not any typographic considerations. 32 * 33 * Much less clear is the choice of width for the Not East Asian 34 * (Neutral) class. Existing practice does not dictate a width for any 35 * of these characters. It would nevertheless make sense 36 * typographically to allocate two character cells to characters such 37 * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be 38 * represented adequately with a single-width glyph. The following 39 * routines at present merely assign a single-cell width to all 40 * neutral characters, in the interest of simplicity. This is not 41 * entirely satisfactory and should be reconsidered before 42 * establishing a formal standard in this area. At the moment, the 43 * decision which Not East Asian (Neutral) characters should be 44 * represented by double-width glyphs cannot yet be answered by 45 * applying a simple rule from the Unicode database content. Setting 46 * up a proper standard for the behavior of UTF-8 character terminals 47 * will require a careful analysis not only of each Unicode character, 48 * but also of each presentation form, something the author of these 49 * routines has avoided to do so far. 50 * 51 * http://www.unicode.org/unicode/reports/tr11/ 52 * 53 * Markus Kuhn -- 2007-05-26 (Unicode 5.0) 54 * 55 * Permission to use, copy, modify, and distribute this software 56 * for any purpose and without fee is hereby granted. The author 57 * disclaims all warranties with regard to this software. 58 * 59 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c 60 */ 61 62#include <apr_lib.h> 63 64#include "svn_utf.h" 65#include "private/svn_utf_private.h" 66 67#include "svn_private_config.h" 68 69struct interval { 70 apr_uint32_t first; 71 apr_uint32_t last; 72}; 73 74/* auxiliary function for binary search in interval table */ 75static int 76bisearch(apr_uint32_t ucs, const struct interval *table, apr_uint32_t max) 77{ 78 apr_uint32_t min = 0; 79 apr_uint32_t mid; 80 81 if (ucs < table[0].first || ucs > table[max].last) 82 return 0; 83 while (max >= min) { 84 mid = (min + max) / 2; 85 if (ucs > table[mid].last) 86 min = mid + 1; 87 else if (ucs < table[mid].first) 88 max = mid - 1; /* this is safe because ucs >= table[0].first */ 89 else 90 return 1; 91 } 92 93 return 0; 94} 95 96 97/* The following two functions define the column width of an ISO 10646 98 * character as follows: 99 * 100 * - The null character (U+0000) has a column width of 0. 101 * 102 * - Other C0/C1 control characters and DEL will lead to a return 103 * value of -1. 104 * 105 * - Non-spacing and enclosing combining characters (general 106 * category code Mn or Me in the Unicode database) have a 107 * column width of 0. 108 * 109 * - SOFT HYPHEN (U+00AD) has a column width of 1. 110 * 111 * - Other format characters (general category code Cf in the Unicode 112 * database) and ZERO WIDTH SPACE (U+200B) have a column width of 0. 113 * 114 * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF) 115 * have a column width of 0. 116 * 117 * - Spacing characters in the East Asian Wide (W) or East Asian 118 * Full-width (F) category as defined in Unicode Technical 119 * Report #11 have a column width of 2. 120 * 121 * - All remaining characters (including all printable 122 * ISO 8859-1 and WGL4 characters, Unicode control characters, 123 * etc.) have a column width of 1. 124 * 125 * This implementation assumes that wchar_t characters are encoded 126 * in ISO 10646. 127 */ 128 129static int 130mk_wcwidth(apr_uint32_t ucs) 131{ 132 /* sorted list of non-overlapping intervals of non-spacing characters */ 133 /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */ 134 static const struct interval combining[] = { 135 { 0x0300, 0x036F }, { 0x0483, 0x0486 }, { 0x0488, 0x0489 }, 136 { 0x0591, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 }, 137 { 0x05C4, 0x05C5 }, { 0x05C7, 0x05C7 }, { 0x0600, 0x0603 }, 138 { 0x0610, 0x0615 }, { 0x064B, 0x065E }, { 0x0670, 0x0670 }, 139 { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, 140 { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A }, 141 { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 }, { 0x0901, 0x0902 }, 142 { 0x093C, 0x093C }, { 0x0941, 0x0948 }, { 0x094D, 0x094D }, 143 { 0x0951, 0x0954 }, { 0x0962, 0x0963 }, { 0x0981, 0x0981 }, 144 { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD }, 145 { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C }, 146 { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D }, 147 { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC }, 148 { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD }, 149 { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 }, { 0x0B3C, 0x0B3C }, 150 { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 }, { 0x0B4D, 0x0B4D }, 151 { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 }, 152 { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 }, 153 { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 }, { 0x0CBC, 0x0CBC }, 154 { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD }, 155 { 0x0CE2, 0x0CE3 }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D }, 156 { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 }, 157 { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E }, 158 { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC }, 159 { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 }, 160 { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E }, 161 { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 }, 162 { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 }, 163 { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 }, 164 { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x135F, 0x135F }, 165 { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, 166 { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, 167 { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, 168 { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, 169 { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, { 0x1939, 0x193B }, 170 { 0x1A17, 0x1A18 }, { 0x1B00, 0x1B03 }, { 0x1B34, 0x1B34 }, 171 { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C }, { 0x1B42, 0x1B42 }, 172 { 0x1B6B, 0x1B73 }, { 0x1DC0, 0x1DCA }, { 0x1DFE, 0x1DFF }, 173 { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x2063 }, 174 { 0x206A, 0x206F }, { 0x20D0, 0x20EF }, { 0x302A, 0x302F }, 175 { 0x3099, 0x309A }, { 0xA806, 0xA806 }, { 0xA80B, 0xA80B }, 176 { 0xA825, 0xA826 }, { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, 177 { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, 178 { 0x10A01, 0x10A03 }, { 0x10A05, 0x10A06 }, { 0x10A0C, 0x10A0F }, 179 { 0x10A38, 0x10A3A }, { 0x10A3F, 0x10A3F }, { 0x1D167, 0x1D169 }, 180 { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD }, 181 { 0x1D242, 0x1D244 }, { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F }, 182 { 0xE0100, 0xE01EF } 183 }; 184 185 /* test for 8-bit control characters */ 186 if (ucs == 0) 187 return 0; 188 if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0)) 189 return -1; 190 191 /* binary search in table of non-spacing characters */ 192 if (bisearch(ucs, combining, 193 sizeof(combining) / sizeof(struct interval) - 1)) 194 return 0; 195 196 /* if we arrive here, ucs is not a combining or C0/C1 control character */ 197 198 return 1 + 199 (ucs >= 0x1100 && 200 (ucs <= 0x115f || /* Hangul Jamo init. consonants */ 201 ucs == 0x2329 || ucs == 0x232a || 202 (ucs >= 0x2e80 && ucs <= 0xa4cf && 203 ucs != 0x303f) || /* CJK ... Yi */ 204 (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */ 205 (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */ 206 (ucs >= 0xfe10 && ucs <= 0xfe19) || /* Vertical forms */ 207 (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */ 208 (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */ 209 (ucs >= 0xffe0 && ucs <= 0xffe6) || 210 (ucs >= 0x20000 && ucs <= 0x2fffd) || 211 (ucs >= 0x30000 && ucs <= 0x3fffd))); 212} 213 214int 215svn_utf_cstring_utf8_width(const char *cstr) 216{ 217 int width = 0; 218 219 if (*cstr == '\0') 220 return 0; 221 222 /* Ensure the conversion below doesn't fail because of encoding errors. */ 223 if (!svn_utf__cstring_is_valid(cstr)) 224 return -1; 225 226 /* Convert the UTF-8 string to UTF-32 (UCS4) which is the format 227 * mk_wcwidth() expects, and get the width of each character. 228 * We don't need much error checking since the input is valid UTF-8. */ 229 while (*cstr) 230 { 231 apr_uint32_t ucs; 232 int nbytes; 233 int lead_mask; 234 int w; 235 int i; 236 237 if ((*cstr & 0x80) == 0) 238 { 239 nbytes = 1; 240 lead_mask = 0x7f; 241 } 242 else if ((*cstr & 0xe0) == 0xc0) 243 { 244 nbytes = 2; 245 lead_mask = 0x1f; 246 } 247 else if ((*cstr & 0xf0) == 0xe0) 248 { 249 nbytes = 3; 250 lead_mask = 0x0f; 251 } 252 else if ((*cstr & 0xf8) == 0xf0) 253 { 254 nbytes = 4; 255 lead_mask = 0x07; 256 } 257 else 258 { 259 /* RFC 3629 restricts UTF-8 to max 4 bytes per character. */ 260 return -1; 261 } 262 263 /* Parse character data from leading byte. */ 264 ucs = (apr_uint32_t)(*cstr & lead_mask); 265 266 /* Parse character data from continuation bytes. */ 267 for (i = 1; i < nbytes; i++) 268 { 269 ucs <<= 6; 270 ucs |= (cstr[i] & 0x3f); 271 } 272 273 cstr += nbytes; 274 275 /* Determine the width of this character and add it to the total. */ 276 w = mk_wcwidth(ucs); 277 if (w == -1) 278 return -1; 279 width += w; 280 } 281 282 return width; 283} 284