xref: /openbsd-src/usr.bin/tmux/utf8.c (revision 505ee9ea3b177e2387d907a91ca7da069f3f14d8) 
1 /* $OpenBSD: utf8.c,v 1.55 2020/06/09 10:37:00 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(flags) (((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 		log_debug("%s: found %.*s = %u", __func__, (int)size, data,
105 		    *index);
106 		*index = ui->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 	log_debug("%s: added %.*s = %u", __func__, (int)size, data, *index);
122 	*index = ui->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 	*width = wcwidth(wc);
230 	if (*width < 0 || *width > 0xff) {
231 		log_debug("UTF-8 %.*s, wcwidth() %d", (int)ud->size, ud->data,
232 		    *width);
233 		return (UTF8_ERROR);
234 	}
235 	return (UTF8_DONE);
236 }
237 
238 /*
239  * Open UTF-8 sequence.
240  *
241  * 11000010-11011111 C2-DF start of 2-byte sequence
242  * 11100000-11101111 E0-EF start of 3-byte sequence
243  * 11110000-11110100 F0-F4 start of 4-byte sequence
244  */
245 enum utf8_state
246 utf8_open(struct utf8_data *ud, u_char ch)
247 {
248 	memset(ud, 0, sizeof *ud);
249 	if (ch >= 0xc2 && ch <= 0xdf)
250 		ud->size = 2;
251 	else if (ch >= 0xe0 && ch <= 0xef)
252 		ud->size = 3;
253 	else if (ch >= 0xf0 && ch <= 0xf4)
254 		ud->size = 4;
255 	else
256 		return (UTF8_ERROR);
257 	utf8_append(ud, ch);
258 	return (UTF8_MORE);
259 }
260 
261 /* Append character to UTF-8, closing if finished. */
262 enum utf8_state
263 utf8_append(struct utf8_data *ud, u_char ch)
264 {
265 	int	width;
266 
267 	if (ud->have >= ud->size)
268 		fatalx("UTF-8 character overflow");
269 	if (ud->size > sizeof ud->data)
270 		fatalx("UTF-8 character size too large");
271 
272 	if (ud->have != 0 && (ch & 0xc0) != 0x80)
273 		ud->width = 0xff;
274 
275 	ud->data[ud->have++] = ch;
276 	if (ud->have != ud->size)
277 		return (UTF8_MORE);
278 
279 	if (ud->width == 0xff)
280 		return (UTF8_ERROR);
281 	if (utf8_width(ud, &width) != UTF8_DONE)
282 		return (UTF8_ERROR);
283 	ud->width = width;
284 
285 	return (UTF8_DONE);
286 }
287 
288 /*
289  * Encode len characters from src into dst, which is guaranteed to have four
290  * bytes available for each character from src (for \abc or UTF-8) plus space
291  * for \0.
292  */
293 int
294 utf8_strvis(char *dst, const char *src, size_t len, int flag)
295 {
296 	struct utf8_data	 ud;
297 	const char		*start = dst, *end = src + len;
298 	enum utf8_state		 more;
299 	size_t			 i;
300 
301 	while (src < end) {
302 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
303 			while (++src < end && more == UTF8_MORE)
304 				more = utf8_append(&ud, *src);
305 			if (more == UTF8_DONE) {
306 				/* UTF-8 character finished. */
307 				for (i = 0; i < ud.size; i++)
308 					*dst++ = ud.data[i];
309 				continue;
310 			}
311 			/* Not a complete, valid UTF-8 character. */
312 			src -= ud.have;
313 		}
314 		if (src[0] == '$' && src < end - 1) {
315 			if (isalpha((u_char)src[1]) ||
316 			    src[1] == '_' ||
317 			    src[1] == '{')
318 				*dst++ = '\\';
319 			*dst++ = '$';
320 		} else if (src < end - 1)
321 			dst = vis(dst, src[0], flag, src[1]);
322 		else if (src < end)
323 			dst = vis(dst, src[0], flag, '\0');
324 		src++;
325 	}
326 	*dst = '\0';
327 	return (dst - start);
328 }
329 
330 /* Same as utf8_strvis but allocate the buffer. */
331 int
332 utf8_stravis(char **dst, const char *src, int flag)
333 {
334 	char	*buf;
335 	int	 len;
336 
337 	buf = xreallocarray(NULL, 4, strlen(src) + 1);
338 	len = utf8_strvis(buf, src, strlen(src), flag);
339 
340 	*dst = xrealloc(buf, len + 1);
341 	return (len);
342 }
343 
344 /* Does this string contain anything that isn't valid UTF-8? */
345 int
346 utf8_isvalid(const char *s)
347 {
348 	struct utf8_data ud;
349 	const char	*end;
350 	enum utf8_state	 more;
351 
352 	end = s + strlen(s);
353 	while (s < end) {
354 		if ((more = utf8_open(&ud, *s)) == UTF8_MORE) {
355 			while (++s < end && more == UTF8_MORE)
356 				more = utf8_append(&ud, *s);
357 			if (more == UTF8_DONE)
358 				continue;
359 			return (0);
360 		}
361 		if (*s < 0x20 || *s > 0x7e)
362 			return (0);
363 		s++;
364 	}
365 	return (1);
366 }
367 
368 /*
369  * Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
370  * the returned string. Anything not valid printable ASCII or UTF-8 is
371  * stripped.
372  */
373 char *
374 utf8_sanitize(const char *src)
375 {
376 	char		*dst = NULL;
377 	size_t		 n = 0;
378 	enum utf8_state	 more;
379 	struct utf8_data ud;
380 	u_int		 i;
381 
382 	while (*src != '\0') {
383 		dst = xreallocarray(dst, n + 1, sizeof *dst);
384 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
385 			while (*++src != '\0' && more == UTF8_MORE)
386 				more = utf8_append(&ud, *src);
387 			if (more == UTF8_DONE) {
388 				dst = xreallocarray(dst, n + ud.width,
389 				    sizeof *dst);
390 				for (i = 0; i < ud.width; i++)
391 					dst[n++] = '_';
392 				continue;
393 			}
394 			src -= ud.have;
395 		}
396 		if (*src > 0x1f && *src < 0x7f)
397 			dst[n++] = *src;
398 		else
399 			dst[n++] = '_';
400 		src++;
401 	}
402 	dst = xreallocarray(dst, n + 1, sizeof *dst);
403 	dst[n] = '\0';
404 	return (dst);
405 }
406 
407 /* Get UTF-8 buffer length. */
408 size_t
409 utf8_strlen(const struct utf8_data *s)
410 {
411 	size_t	i;
412 
413 	for (i = 0; s[i].size != 0; i++)
414 		/* nothing */;
415 	return (i);
416 }
417 
418 /* Get UTF-8 string width. */
419 u_int
420 utf8_strwidth(const struct utf8_data *s, ssize_t n)
421 {
422 	ssize_t	i;
423 	u_int	width = 0;
424 
425 	for (i = 0; s[i].size != 0; i++) {
426 		if (n != -1 && n == i)
427 			break;
428 		width += s[i].width;
429 	}
430 	return (width);
431 }
432 
433 /*
434  * Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
435  * Caller frees.
436  */
437 struct utf8_data *
438 utf8_fromcstr(const char *src)
439 {
440 	struct utf8_data	*dst = NULL;
441 	size_t			 n = 0;
442 	enum utf8_state		 more;
443 
444 	while (*src != '\0') {
445 		dst = xreallocarray(dst, n + 1, sizeof *dst);
446 		if ((more = utf8_open(&dst[n], *src)) == UTF8_MORE) {
447 			while (*++src != '\0' && more == UTF8_MORE)
448 				more = utf8_append(&dst[n], *src);
449 			if (more == UTF8_DONE) {
450 				n++;
451 				continue;
452 			}
453 			src -= dst[n].have;
454 		}
455 		utf8_set(&dst[n], *src);
456 		n++;
457 		src++;
458 	}
459 	dst = xreallocarray(dst, n + 1, sizeof *dst);
460 	dst[n].size = 0;
461 	return (dst);
462 }
463 
464 /* Convert from a buffer of UTF-8 characters into a string. Caller frees. */
465 char *
466 utf8_tocstr(struct utf8_data *src)
467 {
468 	char	*dst = NULL;
469 	size_t	 n = 0;
470 
471 	for(; src->size != 0; src++) {
472 		dst = xreallocarray(dst, n + src->size, 1);
473 		memcpy(dst + n, src->data, src->size);
474 		n += src->size;
475 	}
476 	dst = xreallocarray(dst, n + 1, 1);
477 	dst[n] = '\0';
478 	return (dst);
479 }
480 
481 /* Get width of UTF-8 string. */
482 u_int
483 utf8_cstrwidth(const char *s)
484 {
485 	struct utf8_data	tmp;
486 	u_int			width;
487 	enum utf8_state		more;
488 
489 	width = 0;
490 	while (*s != '\0') {
491 		if ((more = utf8_open(&tmp, *s)) == UTF8_MORE) {
492 			while (*++s != '\0' && more == UTF8_MORE)
493 				more = utf8_append(&tmp, *s);
494 			if (more == UTF8_DONE) {
495 				width += tmp.width;
496 				continue;
497 			}
498 			s -= tmp.have;
499 		}
500 		if (*s > 0x1f && *s != 0x7f)
501 			width++;
502 		s++;
503 	}
504 	return (width);
505 }
506 
507 /* Pad UTF-8 string to width on the left. Caller frees. */
508 char *
509 utf8_padcstr(const char *s, u_int width)
510 {
511 	size_t	 slen;
512 	char	*out;
513 	u_int	 n, i;
514 
515 	n = utf8_cstrwidth(s);
516 	if (n >= width)
517 		return (xstrdup(s));
518 
519 	slen = strlen(s);
520 	out = xmalloc(slen + 1 + (width - n));
521 	memcpy(out, s, slen);
522 	for (i = n; i < width; i++)
523 		out[slen++] = ' ';
524 	out[slen] = '\0';
525 	return (out);
526 }
527 
528 /* Pad UTF-8 string to width on the right. Caller frees. */
529 char *
530 utf8_rpadcstr(const char *s, u_int width)
531 {
532 	size_t	 slen;
533 	char	*out;
534 	u_int	 n, i;
535 
536 	n = utf8_cstrwidth(s);
537 	if (n >= width)
538 		return (xstrdup(s));
539 
540 	slen = strlen(s);
541 	out = xmalloc(slen + 1 + (width - n));
542 	for (i = 0; i < width - n; i++)
543 		out[i] = ' ';
544 	memcpy(out + i, s, slen);
545 	out[i + slen] = '\0';
546 	return (out);
547 }
548 
549 int
550 utf8_cstrhas(const char *s, const struct utf8_data *ud)
551 {
552 	struct utf8_data	*copy, *loop;
553 	int			 found = 0;
554 
555 	copy = utf8_fromcstr(s);
556 	for (loop = copy; loop->size != 0; loop++) {
557 		if (loop->size != ud->size)
558 			continue;
559 		if (memcmp(loop->data, ud->data, loop->size) == 0) {
560 			found = 1;
561 			break;
562 		}
563 	}
564 	free(copy);
565 
566 	return (found);
567 }
568