utf8.con commit Merge branch 'jh/notes' (2949151)
   1#include "git-compat-util.h"
   2#include "strbuf.h"
   3#include "utf8.h"
   4
   5/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
   6
   7struct interval {
   8  int first;
   9  int last;
  10};
  11
  12/* auxiliary function for binary search in interval table */
  13static int bisearch(ucs_char_t ucs, const struct interval *table, int max)
  14{
  15        int min = 0;
  16        int mid;
  17
  18        if (ucs < table[0].first || ucs > table[max].last)
  19                return 0;
  20        while (max >= min) {
  21                mid = (min + max) / 2;
  22                if (ucs > table[mid].last)
  23                        min = mid + 1;
  24                else if (ucs < table[mid].first)
  25                        max = mid - 1;
  26                else
  27                        return 1;
  28        }
  29
  30        return 0;
  31}
  32
  33/* The following two functions define the column width of an ISO 10646
  34 * character as follows:
  35 *
  36 *    - The null character (U+0000) has a column width of 0.
  37 *
  38 *    - Other C0/C1 control characters and DEL will lead to a return
  39 *      value of -1.
  40 *
  41 *    - Non-spacing and enclosing combining characters (general
  42 *      category code Mn or Me in the Unicode database) have a
  43 *      column width of 0.
  44 *
  45 *    - SOFT HYPHEN (U+00AD) has a column width of 1.
  46 *
  47 *    - Other format characters (general category code Cf in the Unicode
  48 *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
  49 *
  50 *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
  51 *      have a column width of 0.
  52 *
  53 *    - Spacing characters in the East Asian Wide (W) or East Asian
  54 *      Full-width (F) category as defined in Unicode Technical
  55 *      Report #11 have a column width of 2.
  56 *
  57 *    - All remaining characters (including all printable
  58 *      ISO 8859-1 and WGL4 characters, Unicode control characters,
  59 *      etc.) have a column width of 1.
  60 *
  61 * This implementation assumes that ucs_char_t characters are encoded
  62 * in ISO 10646.
  63 */
  64
  65static int git_wcwidth(ucs_char_t ch)
  66{
  67        /*
  68         * Sorted list of non-overlapping intervals of non-spacing characters,
  69         * generated by
  70         *   "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
  71         */
  72        static const struct interval combining[] = {
  73                { 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
  74                { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
  75                { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
  76                { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
  77                { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
  78                { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
  79                { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
  80                { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
  81                { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
  82                { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
  83                { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
  84                { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
  85                { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
  86                { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
  87                { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
  88                { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
  89                { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
  90                { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
  91                { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
  92                { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
  93                { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
  94                { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
  95                { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
  96                { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
  97                { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
  98                { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
  99                { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
 100                { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
 101                { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
 102                { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
 103                { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
 104                { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
 105                { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
 106                { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
 107                { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
 108                { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
 109                { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
 110                { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
 111                { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
 112                { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
 113                { 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
 114                { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
 115        };
 116
 117        /* test for 8-bit control characters */
 118        if (ch == 0)
 119                return 0;
 120        if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
 121                return -1;
 122
 123        /* binary search in table of non-spacing characters */
 124        if (bisearch(ch, combining, sizeof(combining)
 125                                / sizeof(struct interval) - 1))
 126                return 0;
 127
 128        /*
 129         * If we arrive here, ch is neither a combining nor a C0/C1
 130         * control character.
 131         */
 132
 133        return 1 +
 134                (ch >= 0x1100 &&
 135                    /* Hangul Jamo init. consonants */
 136                 (ch <= 0x115f ||
 137                  ch == 0x2329 || ch == 0x232a ||
 138                  /* CJK ... Yi */
 139                  (ch >= 0x2e80 && ch <= 0xa4cf &&
 140                   ch != 0x303f) ||
 141                  /* Hangul Syllables */
 142                  (ch >= 0xac00 && ch <= 0xd7a3) ||
 143                  /* CJK Compatibility Ideographs */
 144                  (ch >= 0xf900 && ch <= 0xfaff) ||
 145                  /* CJK Compatibility Forms */
 146                  (ch >= 0xfe30 && ch <= 0xfe6f) ||
 147                  /* Fullwidth Forms */
 148                  (ch >= 0xff00 && ch <= 0xff60) ||
 149                  (ch >= 0xffe0 && ch <= 0xffe6) ||
 150                  (ch >= 0x20000 && ch <= 0x2fffd) ||
 151                  (ch >= 0x30000 && ch <= 0x3fffd)));
 152}
 153
 154/*
 155 * Pick one ucs character starting from the location *start points at,
 156 * and return it, while updating the *start pointer to point at the
 157 * end of that character.  When remainder_p is not NULL, the location
 158 * holds the number of bytes remaining in the string that we are allowed
 159 * to pick from.  Otherwise we are allowed to pick up to the NUL that
 160 * would eventually appear in the string.  *remainder_p is also reduced
 161 * by the number of bytes we have consumed.
 162 *
 163 * If the string was not a valid UTF-8, *start pointer is set to NULL
 164 * and the return value is undefined.
 165 */
 166static ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
 167{
 168        unsigned char *s = (unsigned char *)*start;
 169        ucs_char_t ch;
 170        size_t remainder, incr;
 171
 172        /*
 173         * A caller that assumes NUL terminated text can choose
 174         * not to bother with the remainder length.  We will
 175         * stop at the first NUL.
 176         */
 177        remainder = (remainder_p ? *remainder_p : 999);
 178
 179        if (remainder < 1) {
 180                goto invalid;
 181        } else if (*s < 0x80) {
 182                /* 0xxxxxxx */
 183                ch = *s;
 184                incr = 1;
 185        } else if ((s[0] & 0xe0) == 0xc0) {
 186                /* 110XXXXx 10xxxxxx */
 187                if (remainder < 2 ||
 188                    (s[1] & 0xc0) != 0x80 ||
 189                    (s[0] & 0xfe) == 0xc0)
 190                        goto invalid;
 191                ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
 192                incr = 2;
 193        } else if ((s[0] & 0xf0) == 0xe0) {
 194                /* 1110XXXX 10Xxxxxx 10xxxxxx */
 195                if (remainder < 3 ||
 196                    (s[1] & 0xc0) != 0x80 ||
 197                    (s[2] & 0xc0) != 0x80 ||
 198                    /* overlong? */
 199                    (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
 200                    /* surrogate? */
 201                    (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
 202                    /* U+FFFE or U+FFFF? */
 203                    (s[0] == 0xef && s[1] == 0xbf &&
 204                     (s[2] & 0xfe) == 0xbe))
 205                        goto invalid;
 206                ch = ((s[0] & 0x0f) << 12) |
 207                        ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
 208                incr = 3;
 209        } else if ((s[0] & 0xf8) == 0xf0) {
 210                /* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
 211                if (remainder < 4 ||
 212                    (s[1] & 0xc0) != 0x80 ||
 213                    (s[2] & 0xc0) != 0x80 ||
 214                    (s[3] & 0xc0) != 0x80 ||
 215                    /* overlong? */
 216                    (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
 217                    /* > U+10FFFF? */
 218                    (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
 219                        goto invalid;
 220                ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
 221                        ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
 222                incr = 4;
 223        } else {
 224invalid:
 225                *start = NULL;
 226                return 0;
 227        }
 228
 229        *start += incr;
 230        if (remainder_p)
 231                *remainder_p = remainder - incr;
 232        return ch;
 233}
 234
 235/*
 236 * This function returns the number of columns occupied by the character
 237 * pointed to by the variable start. The pointer is updated to point at
 238 * the next character. When remainder_p is not NULL, it points at the
 239 * location that stores the number of remaining bytes we can use to pick
 240 * a character (see pick_one_utf8_char() above).
 241 */
 242int utf8_width(const char **start, size_t *remainder_p)
 243{
 244        ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
 245        if (!*start)
 246                return 0;
 247        return git_wcwidth(ch);
 248}
 249
 250/*
 251 * Returns the total number of columns required by a null-terminated
 252 * string, assuming that the string is utf8.  Returns strlen() instead
 253 * if the string does not look like a valid utf8 string.
 254 */
 255int utf8_strwidth(const char *string)
 256{
 257        int width = 0;
 258        const char *orig = string;
 259
 260        while (1) {
 261                if (!string)
 262                        return strlen(orig);
 263                if (!*string)
 264                        return width;
 265                width += utf8_width(&string, NULL);
 266        }
 267}
 268
 269int is_utf8(const char *text)
 270{
 271        while (*text) {
 272                if (*text == '\n' || *text == '\t' || *text == '\r') {
 273                        text++;
 274                        continue;
 275                }
 276                utf8_width(&text, NULL);
 277                if (!text)
 278                        return 0;
 279        }
 280        return 1;
 281}
 282
 283static void strbuf_addchars(struct strbuf *sb, int c, size_t n)
 284{
 285        strbuf_grow(sb, n);
 286        memset(sb->buf + sb->len, c, n);
 287        strbuf_setlen(sb, sb->len + n);
 288}
 289
 290static void strbuf_add_indented_text(struct strbuf *buf, const char *text,
 291                                     int indent, int indent2)
 292{
 293        if (indent < 0)
 294                indent = 0;
 295        while (*text) {
 296                const char *eol = strchrnul(text, '\n');
 297                if (*eol == '\n')
 298                        eol++;
 299                strbuf_addchars(buf, ' ', indent);
 300                strbuf_add(buf, text, eol - text);
 301                text = eol;
 302                indent = indent2;
 303        }
 304}
 305
 306static size_t display_mode_esc_sequence_len(const char *s)
 307{
 308        const char *p = s;
 309        if (*p++ != '\033')
 310                return 0;
 311        if (*p++ != '[')
 312                return 0;
 313        while (isdigit(*p) || *p == ';')
 314                p++;
 315        if (*p++ != 'm')
 316                return 0;
 317        return p - s;
 318}
 319
 320/*
 321 * Wrap the text, if necessary. The variable indent is the indent for the
 322 * first line, indent2 is the indent for all other lines.
 323 * If indent is negative, assume that already -indent columns have been
 324 * consumed (and no extra indent is necessary for the first line).
 325 */
 326int strbuf_add_wrapped_text(struct strbuf *buf,
 327                const char *text, int indent1, int indent2, int width)
 328{
 329        int indent, w, assume_utf8 = 1;
 330        const char *bol, *space, *start = text;
 331        size_t orig_len = buf->len;
 332
 333        if (width <= 0) {
 334                strbuf_add_indented_text(buf, text, indent1, indent2);
 335                return 1;
 336        }
 337
 338retry:
 339        bol = text;
 340        w = indent = indent1;
 341        space = NULL;
 342        if (indent < 0) {
 343                w = -indent;
 344                space = text;
 345        }
 346
 347        for (;;) {
 348                char c;
 349                size_t skip;
 350
 351                while ((skip = display_mode_esc_sequence_len(text)))
 352                        text += skip;
 353
 354                c = *text;
 355                if (!c || isspace(c)) {
 356                        if (w < width || !space) {
 357                                const char *start = bol;
 358                                if (!c && text == start)
 359                                        return w;
 360                                if (space)
 361                                        start = space;
 362                                else
 363                                        strbuf_addchars(buf, ' ', indent);
 364                                strbuf_add(buf, start, text - start);
 365                                if (!c)
 366                                        return w;
 367                                space = text;
 368                                if (c == '\t')
 369                                        w |= 0x07;
 370                                else if (c == '\n') {
 371                                        space++;
 372                                        if (*space == '\n') {
 373                                                strbuf_addch(buf, '\n');
 374                                                goto new_line;
 375                                        }
 376                                        else if (!isalnum(*space))
 377                                                goto new_line;
 378                                        else
 379                                                strbuf_addch(buf, ' ');
 380                                }
 381                                w++;
 382                                text++;
 383                        }
 384                        else {
 385new_line:
 386                                strbuf_addch(buf, '\n');
 387                                text = bol = space + isspace(*space);
 388                                space = NULL;
 389                                w = indent = indent2;
 390                        }
 391                        continue;
 392                }
 393                if (assume_utf8) {
 394                        w += utf8_width(&text, NULL);
 395                        if (!text) {
 396                                assume_utf8 = 0;
 397                                text = start;
 398                                strbuf_setlen(buf, orig_len);
 399                                goto retry;
 400                        }
 401                } else {
 402                        w++;
 403                        text++;
 404                }
 405        }
 406}
 407
 408int is_encoding_utf8(const char *name)
 409{
 410        if (!name)
 411                return 1;
 412        if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
 413                return 1;
 414        return 0;
 415}
 416
 417/*
 418 * Given a buffer and its encoding, return it re-encoded
 419 * with iconv.  If the conversion fails, returns NULL.
 420 */
 421#ifndef NO_ICONV
 422#if defined(OLD_ICONV) || (defined(__sun__) && !defined(_XPG6))
 423        typedef const char * iconv_ibp;
 424#else
 425        typedef char * iconv_ibp;
 426#endif
 427char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
 428{
 429        iconv_t conv;
 430        size_t insz, outsz, outalloc;
 431        char *out, *outpos;
 432        iconv_ibp cp;
 433
 434        if (!in_encoding)
 435                return NULL;
 436        conv = iconv_open(out_encoding, in_encoding);
 437        if (conv == (iconv_t) -1)
 438                return NULL;
 439        insz = strlen(in);
 440        outsz = insz;
 441        outalloc = outsz + 1; /* for terminating NUL */
 442        out = xmalloc(outalloc);
 443        outpos = out;
 444        cp = (iconv_ibp)in;
 445
 446        while (1) {
 447                size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
 448
 449                if (cnt == -1) {
 450                        size_t sofar;
 451                        if (errno != E2BIG) {
 452                                free(out);
 453                                iconv_close(conv);
 454                                return NULL;
 455                        }
 456                        /* insz has remaining number of bytes.
 457                         * since we started outsz the same as insz,
 458                         * it is likely that insz is not enough for
 459                         * converting the rest.
 460                         */
 461                        sofar = outpos - out;
 462                        outalloc = sofar + insz * 2 + 32;
 463                        out = xrealloc(out, outalloc);
 464                        outpos = out + sofar;
 465                        outsz = outalloc - sofar - 1;
 466                }
 467                else {
 468                        *outpos = '\0';
 469                        break;
 470                }
 471        }
 472        iconv_close(conv);
 473        return out;
 474}
 475#endif