Merge branch 'esr/maint-doc-fast-import'
[git.git] / utf8.c
blob5c61bbe1131e7bbdd939c8b815bd5222b872e3fb
1 #include "git-compat-util.h"
2 #include "strbuf.h"
3 #include "utf8.h"
5 /* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
7 struct interval {
8 int first;
9 int last;
12 /* auxiliary function for binary search in interval table */
13 static int bisearch(ucs_char_t ucs, const struct interval *table, int max)
15 int min = 0;
16 int mid;
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;
30 return 0;
33 /* The following two functions define the column width of an ISO 10646
34 * character as follows:
36 * - The null character (U+0000) has a column width of 0.
38 * - Other C0/C1 control characters and DEL will lead to a return
39 * value of -1.
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.
45 * - SOFT HYPHEN (U+00AD) has a column width of 1.
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.
50 * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
51 * have a column width of 0.
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.
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.
61 * This implementation assumes that ucs_char_t characters are encoded
62 * in ISO 10646.
65 static int git_wcwidth(ucs_char_t ch)
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".
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 }
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;
123 /* binary search in table of non-spacing characters */
124 if (bisearch(ch, combining, sizeof(combining)
125 / sizeof(struct interval) - 1))
126 return 0;
129 * If we arrive here, ch is neither a combining nor a C0/C1
130 * control character.
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)));
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.
163 * If the string was not a valid UTF-8, *start pointer is set to NULL
164 * and the return value is undefined.
166 static ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
168 unsigned char *s = (unsigned char *)*start;
169 ucs_char_t ch;
170 size_t remainder, incr;
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.
177 remainder = (remainder_p ? *remainder_p : 999);
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 {
224 invalid:
225 *start = NULL;
226 return 0;
229 *start += incr;
230 if (remainder_p)
231 *remainder_p = remainder - incr;
232 return ch;
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).
242 int utf8_width(const char **start, size_t *remainder_p)
244 ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
245 if (!*start)
246 return 0;
247 return git_wcwidth(ch);
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.
255 int utf8_strwidth(const char *string)
257 int width = 0;
258 const char *orig = string;
260 while (1) {
261 if (!string)
262 return strlen(orig);
263 if (!*string)
264 return width;
265 width += utf8_width(&string, NULL);
269 int is_utf8(const char *text)
271 while (*text) {
272 if (*text == '\n' || *text == '\t' || *text == '\r') {
273 text++;
274 continue;
276 utf8_width(&text, NULL);
277 if (!text)
278 return 0;
280 return 1;
283 static void strbuf_addchars(struct strbuf *sb, int c, size_t n)
285 strbuf_grow(sb, n);
286 memset(sb->buf + sb->len, c, n);
287 strbuf_setlen(sb, sb->len + n);
290 static void strbuf_add_indented_text(struct strbuf *buf, const char *text,
291 int indent, int indent2)
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;
306 static size_t display_mode_esc_sequence_len(const char *s)
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;
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).
326 int strbuf_add_wrapped_text(struct strbuf *buf,
327 const char *text, int indent1, int indent2, int width)
329 int indent, w, assume_utf8 = 1;
330 const char *bol, *space, *start = text;
331 size_t orig_len = buf->len;
333 if (width <= 0) {
334 strbuf_add_indented_text(buf, text, indent1, indent2);
335 return 1;
338 retry:
339 bol = text;
340 w = indent = indent1;
341 space = NULL;
342 if (indent < 0) {
343 w = -indent;
344 space = text;
347 for (;;) {
348 char c;
349 size_t skip;
351 while ((skip = display_mode_esc_sequence_len(text)))
352 text += skip;
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;
376 else if (!isalnum(*space))
377 goto new_line;
378 else
379 strbuf_addch(buf, ' ');
381 w++;
382 text++;
384 else {
385 new_line:
386 strbuf_addch(buf, '\n');
387 text = bol = space + isspace(*space);
388 space = NULL;
389 w = indent = indent2;
391 continue;
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;
401 } else {
402 w++;
403 text++;
408 int strbuf_add_wrapped_bytes(struct strbuf *buf, const char *data, int len,
409 int indent, int indent2, int width)
411 char *tmp = xstrndup(data, len);
412 int r = strbuf_add_wrapped_text(buf, tmp, indent, indent2, width);
413 free(tmp);
414 return r;
417 int is_encoding_utf8(const char *name)
419 if (!name)
420 return 1;
421 if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
422 return 1;
423 return 0;
426 int same_encoding(const char *src, const char *dst)
428 if (is_encoding_utf8(src) && is_encoding_utf8(dst))
429 return 1;
430 return !strcasecmp(src, dst);
434 * Given a buffer and its encoding, return it re-encoded
435 * with iconv. If the conversion fails, returns NULL.
437 #ifndef NO_ICONV
438 #if defined(OLD_ICONV) || (defined(__sun__) && !defined(_XPG6))
439 typedef const char * iconv_ibp;
440 #else
441 typedef char * iconv_ibp;
442 #endif
443 char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv)
445 size_t outsz, outalloc;
446 char *out, *outpos;
447 iconv_ibp cp;
449 outsz = insz;
450 outalloc = outsz + 1; /* for terminating NUL */
451 out = xmalloc(outalloc);
452 outpos = out;
453 cp = (iconv_ibp)in;
455 while (1) {
456 size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
458 if (cnt == -1) {
459 size_t sofar;
460 if (errno != E2BIG) {
461 free(out);
462 return NULL;
464 /* insz has remaining number of bytes.
465 * since we started outsz the same as insz,
466 * it is likely that insz is not enough for
467 * converting the rest.
469 sofar = outpos - out;
470 outalloc = sofar + insz * 2 + 32;
471 out = xrealloc(out, outalloc);
472 outpos = out + sofar;
473 outsz = outalloc - sofar - 1;
475 else {
476 *outpos = '\0';
477 break;
480 return out;
483 char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
485 iconv_t conv;
486 char *out;
488 if (!in_encoding)
489 return NULL;
490 conv = iconv_open(out_encoding, in_encoding);
491 if (conv == (iconv_t) -1)
492 return NULL;
493 out = reencode_string_iconv(in, strlen(in), conv);
494 iconv_close(conv);
495 return out;
497 #endif