utf8.con commit utf8: pick_one_utf8_char() (396ccf1)
   1#include "git-compat-util.h"
   2#include "utf8.h"
   3
   4/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
   5
   6struct interval {
   7  int first;
   8  int last;
   9};
  10
  11/* auxiliary function for binary search in interval table */
  12static int bisearch(ucs_char_t ucs, const struct interval *table, int max)
  13{
  14        int min = 0;
  15        int mid;
  16
  17        if (ucs < table[0].first || ucs > table[max].last)
  18                return 0;
  19        while (max >= min) {
  20                mid = (min + max) / 2;
  21                if (ucs > table[mid].last)
  22                        min = mid + 1;
  23                else if (ucs < table[mid].first)
  24                        max = mid - 1;
  25                else
  26                        return 1;
  27        }
  28
  29        return 0;
  30}
  31
  32/* The following two functions define the column width of an ISO 10646
  33 * character as follows:
  34 *
  35 *    - The null character (U+0000) has a column width of 0.
  36 *
  37 *    - Other C0/C1 control characters and DEL will lead to a return
  38 *      value of -1.
  39 *
  40 *    - Non-spacing and enclosing combining characters (general
  41 *      category code Mn or Me in the Unicode database) have a
  42 *      column width of 0.
  43 *
  44 *    - SOFT HYPHEN (U+00AD) has a column width of 1.
  45 *
  46 *    - Other format characters (general category code Cf in the Unicode
  47 *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
  48 *
  49 *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
  50 *      have a column width of 0.
  51 *
  52 *    - Spacing characters in the East Asian Wide (W) or East Asian
  53 *      Full-width (F) category as defined in Unicode Technical
  54 *      Report #11 have a column width of 2.
  55 *
  56 *    - All remaining characters (including all printable
  57 *      ISO 8859-1 and WGL4 characters, Unicode control characters,
  58 *      etc.) have a column width of 1.
  59 *
  60 * This implementation assumes that ucs_char_t characters are encoded
  61 * in ISO 10646.
  62 */
  63
  64static int git_wcwidth(ucs_char_t ch)
  65{
  66        /*
  67         * Sorted list of non-overlapping intervals of non-spacing characters,
  68         * generated by
  69         *   "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
  70         */
  71        static const struct interval combining[] = {
  72                { 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
  73                { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
  74                { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
  75                { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
  76                { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
  77                { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
  78                { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
  79                { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
  80                { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
  81                { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
  82                { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
  83                { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
  84                { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
  85                { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
  86                { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
  87                { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
  88                { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
  89                { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
  90                { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
  91                { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
  92                { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
  93                { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
  94                { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
  95                { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
  96                { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
  97                { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
  98                { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
  99                { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
 100                { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
 101                { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
 102                { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
 103                { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
 104                { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
 105                { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
 106                { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
 107                { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
 108                { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
 109                { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
 110                { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
 111                { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
 112                { 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
 113                { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
 114        };
 115
 116        /* test for 8-bit control characters */
 117        if (ch == 0)
 118                return 0;
 119        if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
 120                return -1;
 121
 122        /* binary search in table of non-spacing characters */
 123        if (bisearch(ch, combining, sizeof(combining)
 124                                / sizeof(struct interval) - 1))
 125                return 0;
 126
 127        /*
 128         * If we arrive here, ch is neither a combining nor a C0/C1
 129         * control character.
 130         */
 131
 132        return 1 +
 133                (ch >= 0x1100 &&
 134                    /* Hangul Jamo init. consonants */
 135                 (ch <= 0x115f ||
 136                  ch == 0x2329 || ch == 0x232a ||
 137                  /* CJK ... Yi */
 138                  (ch >= 0x2e80 && ch <= 0xa4cf &&
 139                   ch != 0x303f) ||
 140                  /* Hangul Syllables */
 141                  (ch >= 0xac00 && ch <= 0xd7a3) ||
 142                  /* CJK Compatibility Ideographs */
 143                  (ch >= 0xf900 && ch <= 0xfaff) ||
 144                  /* CJK Compatibility Forms */
 145                  (ch >= 0xfe30 && ch <= 0xfe6f) ||
 146                  /* Fullwidth Forms */
 147                  (ch >= 0xff00 && ch <= 0xff60) ||
 148                  (ch >= 0xffe0 && ch <= 0xffe6) ||
 149                  (ch >= 0x20000 && ch <= 0x2fffd) ||
 150                  (ch >= 0x30000 && ch <= 0x3fffd)));
 151}
 152
 153/*
 154 * Pick one ucs character starting from the location *start points at,
 155 * and return it, while updating the *start pointer to point at the
 156 * end of that character.
 157 *
 158 * If the string was not a valid UTF-8, *start pointer is set to NULL
 159 * and the return value is undefined.
 160 */
 161ucs_char_t pick_one_utf8_char(const char **start)
 162{
 163        unsigned char *s = (unsigned char *)*start;
 164        ucs_char_t ch;
 165
 166        if (*s < 0x80) {
 167                /* 0xxxxxxx */
 168                ch = *s;
 169                *start += 1;
 170        } else if ((s[0] & 0xe0) == 0xc0) {
 171                /* 110XXXXx 10xxxxxx */
 172                if ((s[1] & 0xc0) != 0x80 ||
 173                                /* overlong? */
 174                                (s[0] & 0xfe) == 0xc0)
 175                        goto invalid;
 176                ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
 177                *start += 2;
 178        } else if ((s[0] & 0xf0) == 0xe0) {
 179                /* 1110XXXX 10Xxxxxx 10xxxxxx */
 180                if ((s[1] & 0xc0) != 0x80 ||
 181                                (s[2] & 0xc0) != 0x80 ||
 182                                /* overlong? */
 183                                (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
 184                                /* surrogate? */
 185                                (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
 186                                /* U+FFFE or U+FFFF? */
 187                                (s[0] == 0xef && s[1] == 0xbf &&
 188                                 (s[2] & 0xfe) == 0xbe))
 189                        goto invalid;
 190                ch = ((s[0] & 0x0f) << 12) |
 191                        ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
 192                *start += 3;
 193        } else if ((s[0] & 0xf8) == 0xf0) {
 194                /* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
 195                if ((s[1] & 0xc0) != 0x80 ||
 196                                (s[2] & 0xc0) != 0x80 ||
 197                                (s[3] & 0xc0) != 0x80 ||
 198                                /* overlong? */
 199                                (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
 200                                /* > U+10FFFF? */
 201                                (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
 202                        goto invalid;
 203                ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
 204                        ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
 205                *start += 4;
 206        } else {
 207invalid:
 208                *start = NULL;
 209                return 0;
 210        }
 211
 212        return ch;
 213}
 214
 215/*
 216 * This function returns the number of columns occupied by the character
 217 * pointed to by the variable start. The pointer is updated to point at
 218 * the next character.  If it was not valid UTF-8, the pointer is set to
 219 * NULL.
 220 */
 221int utf8_width(const char **start)
 222{
 223        ucs_char_t ch = pick_one_utf8_char(start);
 224        if (!*start)
 225                return 0;
 226        return git_wcwidth(ch);
 227}
 228
 229int is_utf8(const char *text)
 230{
 231        while (*text) {
 232                if (*text == '\n' || *text == '\t' || *text == '\r') {
 233                        text++;
 234                        continue;
 235                }
 236                utf8_width(&text);
 237                if (!text)
 238                        return 0;
 239        }
 240        return 1;
 241}
 242
 243static void print_spaces(int count)
 244{
 245        static const char s[] = "                    ";
 246        while (count >= sizeof(s)) {
 247                fwrite(s, sizeof(s) - 1, 1, stdout);
 248                count -= sizeof(s) - 1;
 249        }
 250        fwrite(s, count, 1, stdout);
 251}
 252
 253/*
 254 * Wrap the text, if necessary. The variable indent is the indent for the
 255 * first line, indent2 is the indent for all other lines.
 256 * If indent is negative, assume that already -indent columns have been
 257 * consumed (and no extra indent is necessary for the first line).
 258 */
 259int print_wrapped_text(const char *text, int indent, int indent2, int width)
 260{
 261        int w = indent, assume_utf8 = is_utf8(text);
 262        const char *bol = text, *space = NULL;
 263
 264        if (indent < 0) {
 265                w = -indent;
 266                space = text;
 267        }
 268
 269        for (;;) {
 270                char c = *text;
 271                if (!c || isspace(c)) {
 272                        if (w < width || !space) {
 273                                const char *start = bol;
 274                                if (space)
 275                                        start = space;
 276                                else
 277                                        print_spaces(indent);
 278                                fwrite(start, text - start, 1, stdout);
 279                                if (!c)
 280                                        return w;
 281                                else if (c == '\t')
 282                                        w |= 0x07;
 283                                space = text;
 284                                w++;
 285                                text++;
 286                        }
 287                        else {
 288                                putchar('\n');
 289                                text = bol = space + isspace(*space);
 290                                space = NULL;
 291                                w = indent = indent2;
 292                        }
 293                        continue;
 294                }
 295                if (assume_utf8)
 296                        w += utf8_width(&text);
 297                else {
 298                        w++;
 299                        text++;
 300                }
 301        }
 302}
 303
 304int is_encoding_utf8(const char *name)
 305{
 306        if (!name)
 307                return 1;
 308        if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
 309                return 1;
 310        return 0;
 311}
 312
 313/*
 314 * Given a buffer and its encoding, return it re-encoded
 315 * with iconv.  If the conversion fails, returns NULL.
 316 */
 317#ifndef NO_ICONV
 318#ifdef OLD_ICONV
 319        typedef const char * iconv_ibp;
 320#else
 321        typedef char * iconv_ibp;
 322#endif
 323char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
 324{
 325        iconv_t conv;
 326        size_t insz, outsz, outalloc;
 327        char *out, *outpos;
 328        iconv_ibp cp;
 329
 330        if (!in_encoding)
 331                return NULL;
 332        conv = iconv_open(out_encoding, in_encoding);
 333        if (conv == (iconv_t) -1)
 334                return NULL;
 335        insz = strlen(in);
 336        outsz = insz;
 337        outalloc = outsz + 1; /* for terminating NUL */
 338        out = xmalloc(outalloc);
 339        outpos = out;
 340        cp = (iconv_ibp)in;
 341
 342        while (1) {
 343                size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
 344
 345                if (cnt == -1) {
 346                        size_t sofar;
 347                        if (errno != E2BIG) {
 348                                free(out);
 349                                iconv_close(conv);
 350                                return NULL;
 351                        }
 352                        /* insz has remaining number of bytes.
 353                         * since we started outsz the same as insz,
 354                         * it is likely that insz is not enough for
 355                         * converting the rest.
 356                         */
 357                        sofar = outpos - out;
 358                        outalloc = sofar + insz * 2 + 32;
 359                        out = xrealloc(out, outalloc);
 360                        outpos = out + sofar;
 361                        outsz = outalloc - sofar - 1;
 362                }
 363                else {
 364                        *outpos = '\0';
 365                        break;
 366                }
 367        }
 368        iconv_close(conv);
 369        return out;
 370}
 371#endif