utf8.con commit Merge git://repo.or.cz/git-gui (731ab1f)
   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.  When remainder_p is not NULL, the location
 157 * holds the number of bytes remaining in the string that we are allowed
 158 * to pick from.  Otherwise we are allowed to pick up to the NUL that
 159 * would eventually appear in the string.  *remainder_p is also reduced
 160 * by the number of bytes we have consumed.
 161 *
 162 * If the string was not a valid UTF-8, *start pointer is set to NULL
 163 * and the return value is undefined.
 164 */
 165ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
 166{
 167        unsigned char *s = (unsigned char *)*start;
 168        ucs_char_t ch;
 169        size_t remainder, incr;
 170
 171        /*
 172         * A caller that assumes NUL terminated text can choose
 173         * not to bother with the remainder length.  We will
 174         * stop at the first NUL.
 175         */
 176        remainder = (remainder_p ? *remainder_p : 999);
 177
 178        if (remainder < 1) {
 179                goto invalid;
 180        } else if (*s < 0x80) {
 181                /* 0xxxxxxx */
 182                ch = *s;
 183                incr = 1;
 184        } else if ((s[0] & 0xe0) == 0xc0) {
 185                /* 110XXXXx 10xxxxxx */
 186                if (remainder < 2 ||
 187                    (s[1] & 0xc0) != 0x80 ||
 188                    (s[0] & 0xfe) == 0xc0)
 189                        goto invalid;
 190                ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
 191                incr = 2;
 192        } else if ((s[0] & 0xf0) == 0xe0) {
 193                /* 1110XXXX 10Xxxxxx 10xxxxxx */
 194                if (remainder < 3 ||
 195                    (s[1] & 0xc0) != 0x80 ||
 196                    (s[2] & 0xc0) != 0x80 ||
 197                    /* overlong? */
 198                    (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
 199                    /* surrogate? */
 200                    (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
 201                    /* U+FFFE or U+FFFF? */
 202                    (s[0] == 0xef && s[1] == 0xbf &&
 203                     (s[2] & 0xfe) == 0xbe))
 204                        goto invalid;
 205                ch = ((s[0] & 0x0f) << 12) |
 206                        ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
 207                incr = 3;
 208        } else if ((s[0] & 0xf8) == 0xf0) {
 209                /* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
 210                if (remainder < 4 ||
 211                    (s[1] & 0xc0) != 0x80 ||
 212                    (s[2] & 0xc0) != 0x80 ||
 213                    (s[3] & 0xc0) != 0x80 ||
 214                    /* overlong? */
 215                    (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
 216                    /* > U+10FFFF? */
 217                    (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
 218                        goto invalid;
 219                ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
 220                        ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
 221                incr = 4;
 222        } else {
 223invalid:
 224                *start = NULL;
 225                return 0;
 226        }
 227
 228        *start += incr;
 229        if (remainder_p)
 230                *remainder_p = remainder - incr;
 231        return ch;
 232}
 233
 234/*
 235 * This function returns the number of columns occupied by the character
 236 * pointed to by the variable start. The pointer is updated to point at
 237 * the next character. When remainder_p is not NULL, it points at the
 238 * location that stores the number of remaining bytes we can use to pick
 239 * a character (see pick_one_utf8_char() above).
 240 */
 241int utf8_width(const char **start, size_t *remainder_p)
 242{
 243        ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
 244        if (!*start)
 245                return 0;
 246        return git_wcwidth(ch);
 247}
 248
 249int is_utf8(const char *text)
 250{
 251        while (*text) {
 252                if (*text == '\n' || *text == '\t' || *text == '\r') {
 253                        text++;
 254                        continue;
 255                }
 256                utf8_width(&text, NULL);
 257                if (!text)
 258                        return 0;
 259        }
 260        return 1;
 261}
 262
 263static void print_spaces(int count)
 264{
 265        static const char s[] = "                    ";
 266        while (count >= sizeof(s)) {
 267                fwrite(s, sizeof(s) - 1, 1, stdout);
 268                count -= sizeof(s) - 1;
 269        }
 270        fwrite(s, count, 1, stdout);
 271}
 272
 273/*
 274 * Wrap the text, if necessary. The variable indent is the indent for the
 275 * first line, indent2 is the indent for all other lines.
 276 * If indent is negative, assume that already -indent columns have been
 277 * consumed (and no extra indent is necessary for the first line).
 278 */
 279int print_wrapped_text(const char *text, int indent, int indent2, int width)
 280{
 281        int w = indent, assume_utf8 = is_utf8(text);
 282        const char *bol = text, *space = NULL;
 283
 284        if (indent < 0) {
 285                w = -indent;
 286                space = text;
 287        }
 288
 289        for (;;) {
 290                char c = *text;
 291                if (!c || isspace(c)) {
 292                        if (w < width || !space) {
 293                                const char *start = bol;
 294                                if (space)
 295                                        start = space;
 296                                else
 297                                        print_spaces(indent);
 298                                fwrite(start, text - start, 1, stdout);
 299                                if (!c)
 300                                        return w;
 301                                else if (c == '\t')
 302                                        w |= 0x07;
 303                                space = text;
 304                                w++;
 305                                text++;
 306                        }
 307                        else {
 308                                putchar('\n');
 309                                text = bol = space + isspace(*space);
 310                                space = NULL;
 311                                w = indent = indent2;
 312                        }
 313                        continue;
 314                }
 315                if (assume_utf8)
 316                        w += utf8_width(&text, NULL);
 317                else {
 318                        w++;
 319                        text++;
 320                }
 321        }
 322}
 323
 324int is_encoding_utf8(const char *name)
 325{
 326        if (!name)
 327                return 1;
 328        if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
 329                return 1;
 330        return 0;
 331}
 332
 333/*
 334 * Given a buffer and its encoding, return it re-encoded
 335 * with iconv.  If the conversion fails, returns NULL.
 336 */
 337#ifndef NO_ICONV
 338#ifdef OLD_ICONV
 339        typedef const char * iconv_ibp;
 340#else
 341        typedef char * iconv_ibp;
 342#endif
 343char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
 344{
 345        iconv_t conv;
 346        size_t insz, outsz, outalloc;
 347        char *out, *outpos;
 348        iconv_ibp cp;
 349
 350        if (!in_encoding)
 351                return NULL;
 352        conv = iconv_open(out_encoding, in_encoding);
 353        if (conv == (iconv_t) -1)
 354                return NULL;
 355        insz = strlen(in);
 356        outsz = insz;
 357        outalloc = outsz + 1; /* for terminating NUL */
 358        out = xmalloc(outalloc);
 359        outpos = out;
 360        cp = (iconv_ibp)in;
 361
 362        while (1) {
 363                size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
 364
 365                if (cnt == -1) {
 366                        size_t sofar;
 367                        if (errno != E2BIG) {
 368                                free(out);
 369                                iconv_close(conv);
 370                                return NULL;
 371                        }
 372                        /* insz has remaining number of bytes.
 373                         * since we started outsz the same as insz,
 374                         * it is likely that insz is not enough for
 375                         * converting the rest.
 376                         */
 377                        sofar = outpos - out;
 378                        outalloc = sofar + insz * 2 + 32;
 379                        out = xrealloc(out, outalloc);
 380                        outpos = out + sofar;
 381                        outsz = outalloc - sofar - 1;
 382                }
 383                else {
 384                        *outpos = '\0';
 385                        break;
 386                }
 387        }
 388        iconv_close(conv);
 389        return out;
 390}
 391#endif