xref: /openbsd-src/usr.bin/tmux/utf8.c (revision ff0e7be1ebbcc809ea8ad2b6dafe215824da9e46)
1 /* $OpenBSD: utf8.c,v 1.60 2023/01/08 22:15:30 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 
21 #include <ctype.h>
22 #include <errno.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <vis.h>
26 #include <wchar.h>
27 
28 #include "tmux.h"
29 
30 struct utf8_item {
31 	RB_ENTRY(utf8_item)	index_entry;
32 	u_int			index;
33 
34 	RB_ENTRY(utf8_item)	data_entry;
35 	char			data[UTF8_SIZE];
36 	u_char			size;
37 };
38 
39 static int
40 utf8_data_cmp(struct utf8_item *ui1, struct utf8_item *ui2)
41 {
42 	if (ui1->size < ui2->size)
43 		return (-1);
44 	if (ui1->size > ui2->size)
45 		return (1);
46 	return (memcmp(ui1->data, ui2->data, ui1->size));
47 }
48 RB_HEAD(utf8_data_tree, utf8_item);
49 RB_GENERATE_STATIC(utf8_data_tree, utf8_item, data_entry, utf8_data_cmp);
50 static struct utf8_data_tree utf8_data_tree = RB_INITIALIZER(utf8_data_tree);
51 
52 static int
53 utf8_index_cmp(struct utf8_item *ui1, struct utf8_item *ui2)
54 {
55 	if (ui1->index < ui2->index)
56 		return (-1);
57 	if (ui1->index > ui2->index)
58 		return (1);
59 	return (0);
60 }
61 RB_HEAD(utf8_index_tree, utf8_item);
62 RB_GENERATE_STATIC(utf8_index_tree, utf8_item, index_entry, utf8_index_cmp);
63 static struct utf8_index_tree utf8_index_tree = RB_INITIALIZER(utf8_index_tree);
64 
65 static u_int utf8_next_index;
66 
67 #define UTF8_GET_SIZE(uc) (((uc) >> 24) & 0x1f)
68 #define UTF8_GET_WIDTH(uc) (((uc) >> 29) - 1)
69 
70 #define UTF8_SET_SIZE(size) (((utf8_char)(size)) << 24)
71 #define UTF8_SET_WIDTH(width) ((((utf8_char)(width)) + 1) << 29)
72 
73 /* Get a UTF-8 item from data. */
74 static struct utf8_item *
75 utf8_item_by_data(const char *data, size_t size)
76 {
77 	struct utf8_item	ui;
78 
79 	memcpy(ui.data, data, size);
80 	ui.size = size;
81 
82 	return (RB_FIND(utf8_data_tree, &utf8_data_tree, &ui));
83 }
84 
85 /* Get a UTF-8 item from data. */
86 static struct utf8_item *
87 utf8_item_by_index(u_int index)
88 {
89 	struct utf8_item	ui;
90 
91 	ui.index = index;
92 
93 	return (RB_FIND(utf8_index_tree, &utf8_index_tree, &ui));
94 }
95 
96 /* Add a UTF-8 item. */
97 static int
98 utf8_put_item(const char *data, size_t size, u_int *index)
99 {
100 	struct utf8_item	*ui;
101 
102 	ui = utf8_item_by_data(data, size);
103 	if (ui != NULL) {
104 		*index = ui->index;
105 		log_debug("%s: found %.*s = %u", __func__, (int)size, data,
106 		    *index);
107 		return (0);
108 	}
109 
110 	if (utf8_next_index == 0xffffff + 1)
111 		return (-1);
112 
113 	ui = xcalloc(1, sizeof *ui);
114 	ui->index = utf8_next_index++;
115 	RB_INSERT(utf8_index_tree, &utf8_index_tree, ui);
116 
117 	memcpy(ui->data, data, size);
118 	ui->size = size;
119 	RB_INSERT(utf8_data_tree, &utf8_data_tree, ui);
120 
121 	*index = ui->index;
122 	log_debug("%s: added %.*s = %u", __func__, (int)size, data, *index);
123 	return (0);
124 }
125 
126 /* Get UTF-8 character from data. */
127 enum utf8_state
128 utf8_from_data(const struct utf8_data *ud, utf8_char *uc)
129 {
130 	u_int	index;
131 
132 	if (ud->width > 2)
133 		fatalx("invalid UTF-8 width: %u", ud->width);
134 
135 	if (ud->size > UTF8_SIZE)
136 		goto fail;
137 	if (ud->size <= 3) {
138 		index = (((utf8_char)ud->data[2] << 16)|
139 		          ((utf8_char)ud->data[1] << 8)|
140 		          ((utf8_char)ud->data[0]));
141 	} else if (utf8_put_item(ud->data, ud->size, &index) != 0)
142 		goto fail;
143 	*uc = UTF8_SET_SIZE(ud->size)|UTF8_SET_WIDTH(ud->width)|index;
144 	log_debug("%s: (%d %d %.*s) -> %08x", __func__, ud->width, ud->size,
145 	    (int)ud->size, ud->data, *uc);
146 	return (UTF8_DONE);
147 
148 fail:
149 	if (ud->width == 0)
150 		*uc = UTF8_SET_SIZE(0)|UTF8_SET_WIDTH(0);
151 	else if (ud->width == 1)
152 		*uc = UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|0x20;
153 	else
154 		*uc = UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|0x2020;
155 	return (UTF8_ERROR);
156 }
157 
158 /* Get UTF-8 data from character. */
159 void
160 utf8_to_data(utf8_char uc, struct utf8_data *ud)
161 {
162 	struct utf8_item	*ui;
163 	u_int			 index;
164 
165 	memset(ud, 0, sizeof *ud);
166 	ud->size = ud->have = UTF8_GET_SIZE(uc);
167 	ud->width = UTF8_GET_WIDTH(uc);
168 
169 	if (ud->size <= 3) {
170 		ud->data[2] = (uc >> 16);
171 		ud->data[1] = ((uc >> 8) & 0xff);
172 		ud->data[0] = (uc & 0xff);
173 	} else {
174 		index = (uc & 0xffffff);
175 		if ((ui = utf8_item_by_index(index)) == NULL)
176 			memset(ud->data, ' ', ud->size);
177 		else
178 			memcpy(ud->data, ui->data, ud->size);
179 	}
180 
181 	log_debug("%s: %08x -> (%d %d %.*s)", __func__, uc, ud->width, ud->size,
182 	    (int)ud->size, ud->data);
183 }
184 
185 /* Get UTF-8 character from a single ASCII character. */
186 u_int
187 utf8_build_one(u_char ch)
188 {
189 	return (UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|ch);
190 }
191 
192 /* Set a single character. */
193 void
194 utf8_set(struct utf8_data *ud, u_char ch)
195 {
196 	static const struct utf8_data empty = { { 0 }, 1, 1, 1 };
197 
198 	memcpy(ud, &empty, sizeof *ud);
199 	*ud->data = ch;
200 }
201 
202 /* Copy UTF-8 character. */
203 void
204 utf8_copy(struct utf8_data *to, const struct utf8_data *from)
205 {
206 	u_int	i;
207 
208 	memcpy(to, from, sizeof *to);
209 
210 	for (i = to->size; i < sizeof to->data; i++)
211 		to->data[i] = '\0';
212 }
213 
214 /* Get width of Unicode character. */
215 static enum utf8_state
216 utf8_width(struct utf8_data *ud, int *width)
217 {
218 	wchar_t	wc;
219 
220 	switch (mbtowc(&wc, ud->data, ud->size)) {
221 	case -1:
222 		log_debug("UTF-8 %.*s, mbtowc() %d", (int)ud->size, ud->data,
223 		    errno);
224 		mbtowc(NULL, NULL, MB_CUR_MAX);
225 		return (UTF8_ERROR);
226 	case 0:
227 		return (UTF8_ERROR);
228 	}
229 	log_debug("UTF-8 %.*s is %08X", (int)ud->size, ud->data, (u_int)wc);
230 	*width = wcwidth(wc);
231 	log_debug("wcwidth(%08X) returned %d", (u_int)wc, *width);
232 	if (*width < 0) {
233 		/*
234 		 * C1 control characters are nonprintable, so they are always
235 		 * zero width.
236 		 */
237 		*width = (wc >= 0x80 && wc <= 0x9f) ? 0 : 1;
238 	}
239 	if (*width >= 0 && *width <= 0xff)
240 		return (UTF8_DONE);
241 	return (UTF8_ERROR);
242 }
243 
244 /*
245  * Open UTF-8 sequence.
246  *
247  * 11000010-11011111 C2-DF start of 2-byte sequence
248  * 11100000-11101111 E0-EF start of 3-byte sequence
249  * 11110000-11110100 F0-F4 start of 4-byte sequence
250  */
251 enum utf8_state
252 utf8_open(struct utf8_data *ud, u_char ch)
253 {
254 	memset(ud, 0, sizeof *ud);
255 	if (ch >= 0xc2 && ch <= 0xdf)
256 		ud->size = 2;
257 	else if (ch >= 0xe0 && ch <= 0xef)
258 		ud->size = 3;
259 	else if (ch >= 0xf0 && ch <= 0xf4)
260 		ud->size = 4;
261 	else
262 		return (UTF8_ERROR);
263 	utf8_append(ud, ch);
264 	return (UTF8_MORE);
265 }
266 
267 /* Append character to UTF-8, closing if finished. */
268 enum utf8_state
269 utf8_append(struct utf8_data *ud, u_char ch)
270 {
271 	int	width;
272 
273 	if (ud->have >= ud->size)
274 		fatalx("UTF-8 character overflow");
275 	if (ud->size > sizeof ud->data)
276 		fatalx("UTF-8 character size too large");
277 
278 	if (ud->have != 0 && (ch & 0xc0) != 0x80)
279 		ud->width = 0xff;
280 
281 	ud->data[ud->have++] = ch;
282 	if (ud->have != ud->size)
283 		return (UTF8_MORE);
284 
285 	if (ud->width == 0xff)
286 		return (UTF8_ERROR);
287 	if (utf8_width(ud, &width) != UTF8_DONE)
288 		return (UTF8_ERROR);
289 	ud->width = width;
290 
291 	return (UTF8_DONE);
292 }
293 
294 /*
295  * Encode len characters from src into dst, which is guaranteed to have four
296  * bytes available for each character from src (for \abc or UTF-8) plus space
297  * for \0.
298  */
299 int
300 utf8_strvis(char *dst, const char *src, size_t len, int flag)
301 {
302 	struct utf8_data	 ud;
303 	const char		*start = dst, *end = src + len;
304 	enum utf8_state		 more;
305 	size_t			 i;
306 
307 	while (src < end) {
308 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
309 			while (++src < end && more == UTF8_MORE)
310 				more = utf8_append(&ud, *src);
311 			if (more == UTF8_DONE) {
312 				/* UTF-8 character finished. */
313 				for (i = 0; i < ud.size; i++)
314 					*dst++ = ud.data[i];
315 				continue;
316 			}
317 			/* Not a complete, valid UTF-8 character. */
318 			src -= ud.have;
319 		}
320 		if (src[0] == '$' && src < end - 1) {
321 			if (isalpha((u_char)src[1]) ||
322 			    src[1] == '_' ||
323 			    src[1] == '{')
324 				*dst++ = '\\';
325 			*dst++ = '$';
326 		} else if (src < end - 1)
327 			dst = vis(dst, src[0], flag, src[1]);
328 		else if (src < end)
329 			dst = vis(dst, src[0], flag, '\0');
330 		src++;
331 	}
332 	*dst = '\0';
333 	return (dst - start);
334 }
335 
336 /* Same as utf8_strvis but allocate the buffer. */
337 int
338 utf8_stravis(char **dst, const char *src, int flag)
339 {
340 	char	*buf;
341 	int	 len;
342 
343 	buf = xreallocarray(NULL, 4, strlen(src) + 1);
344 	len = utf8_strvis(buf, src, strlen(src), flag);
345 
346 	*dst = xrealloc(buf, len + 1);
347 	return (len);
348 }
349 
350 /* Same as utf8_strvis but allocate the buffer. */
351 int
352 utf8_stravisx(char **dst, const char *src, size_t srclen, int flag)
353 {
354 	char	*buf;
355 	int	 len;
356 
357 	buf = xreallocarray(NULL, 4, srclen + 1);
358 	len = utf8_strvis(buf, src, srclen, flag);
359 
360 	*dst = xrealloc(buf, len + 1);
361 	return (len);
362 }
363 
364 /* Does this string contain anything that isn't valid UTF-8? */
365 int
366 utf8_isvalid(const char *s)
367 {
368 	struct utf8_data ud;
369 	const char	*end;
370 	enum utf8_state	 more;
371 
372 	end = s + strlen(s);
373 	while (s < end) {
374 		if ((more = utf8_open(&ud, *s)) == UTF8_MORE) {
375 			while (++s < end && more == UTF8_MORE)
376 				more = utf8_append(&ud, *s);
377 			if (more == UTF8_DONE)
378 				continue;
379 			return (0);
380 		}
381 		if (*s < 0x20 || *s > 0x7e)
382 			return (0);
383 		s++;
384 	}
385 	return (1);
386 }
387 
388 /*
389  * Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
390  * the returned string. Anything not valid printable ASCII or UTF-8 is
391  * stripped.
392  */
393 char *
394 utf8_sanitize(const char *src)
395 {
396 	char		*dst = NULL;
397 	size_t		 n = 0;
398 	enum utf8_state	 more;
399 	struct utf8_data ud;
400 	u_int		 i;
401 
402 	while (*src != '\0') {
403 		dst = xreallocarray(dst, n + 1, sizeof *dst);
404 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
405 			while (*++src != '\0' && more == UTF8_MORE)
406 				more = utf8_append(&ud, *src);
407 			if (more == UTF8_DONE) {
408 				dst = xreallocarray(dst, n + ud.width,
409 				    sizeof *dst);
410 				for (i = 0; i < ud.width; i++)
411 					dst[n++] = '_';
412 				continue;
413 			}
414 			src -= ud.have;
415 		}
416 		if (*src > 0x1f && *src < 0x7f)
417 			dst[n++] = *src;
418 		else
419 			dst[n++] = '_';
420 		src++;
421 	}
422 	dst = xreallocarray(dst, n + 1, sizeof *dst);
423 	dst[n] = '\0';
424 	return (dst);
425 }
426 
427 /* Get UTF-8 buffer length. */
428 size_t
429 utf8_strlen(const struct utf8_data *s)
430 {
431 	size_t	i;
432 
433 	for (i = 0; s[i].size != 0; i++)
434 		/* nothing */;
435 	return (i);
436 }
437 
438 /* Get UTF-8 string width. */
439 u_int
440 utf8_strwidth(const struct utf8_data *s, ssize_t n)
441 {
442 	ssize_t	i;
443 	u_int	width = 0;
444 
445 	for (i = 0; s[i].size != 0; i++) {
446 		if (n != -1 && n == i)
447 			break;
448 		width += s[i].width;
449 	}
450 	return (width);
451 }
452 
453 /*
454  * Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
455  * Caller frees.
456  */
457 struct utf8_data *
458 utf8_fromcstr(const char *src)
459 {
460 	struct utf8_data	*dst = NULL;
461 	size_t			 n = 0;
462 	enum utf8_state		 more;
463 
464 	while (*src != '\0') {
465 		dst = xreallocarray(dst, n + 1, sizeof *dst);
466 		if ((more = utf8_open(&dst[n], *src)) == UTF8_MORE) {
467 			while (*++src != '\0' && more == UTF8_MORE)
468 				more = utf8_append(&dst[n], *src);
469 			if (more == UTF8_DONE) {
470 				n++;
471 				continue;
472 			}
473 			src -= dst[n].have;
474 		}
475 		utf8_set(&dst[n], *src);
476 		n++;
477 		src++;
478 	}
479 	dst = xreallocarray(dst, n + 1, sizeof *dst);
480 	dst[n].size = 0;
481 	return (dst);
482 }
483 
484 /* Convert from a buffer of UTF-8 characters into a string. Caller frees. */
485 char *
486 utf8_tocstr(struct utf8_data *src)
487 {
488 	char	*dst = NULL;
489 	size_t	 n = 0;
490 
491 	for(; src->size != 0; src++) {
492 		dst = xreallocarray(dst, n + src->size, 1);
493 		memcpy(dst + n, src->data, src->size);
494 		n += src->size;
495 	}
496 	dst = xreallocarray(dst, n + 1, 1);
497 	dst[n] = '\0';
498 	return (dst);
499 }
500 
501 /* Get width of UTF-8 string. */
502 u_int
503 utf8_cstrwidth(const char *s)
504 {
505 	struct utf8_data	tmp;
506 	u_int			width;
507 	enum utf8_state		more;
508 
509 	width = 0;
510 	while (*s != '\0') {
511 		if ((more = utf8_open(&tmp, *s)) == UTF8_MORE) {
512 			while (*++s != '\0' && more == UTF8_MORE)
513 				more = utf8_append(&tmp, *s);
514 			if (more == UTF8_DONE) {
515 				width += tmp.width;
516 				continue;
517 			}
518 			s -= tmp.have;
519 		}
520 		if (*s > 0x1f && *s != 0x7f)
521 			width++;
522 		s++;
523 	}
524 	return (width);
525 }
526 
527 /* Pad UTF-8 string to width on the left. Caller frees. */
528 char *
529 utf8_padcstr(const char *s, u_int width)
530 {
531 	size_t	 slen;
532 	char	*out;
533 	u_int	 n, i;
534 
535 	n = utf8_cstrwidth(s);
536 	if (n >= width)
537 		return (xstrdup(s));
538 
539 	slen = strlen(s);
540 	out = xmalloc(slen + 1 + (width - n));
541 	memcpy(out, s, slen);
542 	for (i = n; i < width; i++)
543 		out[slen++] = ' ';
544 	out[slen] = '\0';
545 	return (out);
546 }
547 
548 /* Pad UTF-8 string to width on the right. Caller frees. */
549 char *
550 utf8_rpadcstr(const char *s, u_int width)
551 {
552 	size_t	 slen;
553 	char	*out;
554 	u_int	 n, i;
555 
556 	n = utf8_cstrwidth(s);
557 	if (n >= width)
558 		return (xstrdup(s));
559 
560 	slen = strlen(s);
561 	out = xmalloc(slen + 1 + (width - n));
562 	for (i = 0; i < width - n; i++)
563 		out[i] = ' ';
564 	memcpy(out + i, s, slen);
565 	out[i + slen] = '\0';
566 	return (out);
567 }
568 
569 int
570 utf8_cstrhas(const char *s, const struct utf8_data *ud)
571 {
572 	struct utf8_data	*copy, *loop;
573 	int			 found = 0;
574 
575 	copy = utf8_fromcstr(s);
576 	for (loop = copy; loop->size != 0; loop++) {
577 		if (loop->size != ud->size)
578 			continue;
579 		if (memcmp(loop->data, ud->data, loop->size) == 0) {
580 			found = 1;
581 			break;
582 		}
583 	}
584 	free(copy);
585 
586 	return (found);
587 }
588