xref: /openbsd-src/usr.bin/tmux/utf8.c (revision 4b70baf6e17fc8b27fc1f7fa7929335753fa94c3)
1 /* $OpenBSD: utf8.c,v 1.40 2019/03/18 20:53:33 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 <errno.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <vis.h>
25 #include <wchar.h>
26 
27 #include "tmux.h"
28 
29 static int	utf8_width(wchar_t);
30 
31 /* Set a single character. */
32 void
33 utf8_set(struct utf8_data *ud, u_char ch)
34 {
35 	static const struct utf8_data empty = { { 0 }, 1, 1, 1 };
36 
37 	memcpy(ud, &empty, sizeof *ud);
38 	*ud->data = ch;
39 }
40 
41 /* Copy UTF-8 character. */
42 void
43 utf8_copy(struct utf8_data *to, const struct utf8_data *from)
44 {
45 	u_int	i;
46 
47 	memcpy(to, from, sizeof *to);
48 
49 	for (i = to->size; i < sizeof to->data; i++)
50 		to->data[i] = '\0';
51 }
52 
53 /*
54  * Open UTF-8 sequence.
55  *
56  * 11000010-11011111 C2-DF start of 2-byte sequence
57  * 11100000-11101111 E0-EF start of 3-byte sequence
58  * 11110000-11110100 F0-F4 start of 4-byte sequence
59  */
60 enum utf8_state
61 utf8_open(struct utf8_data *ud, u_char ch)
62 {
63 	memset(ud, 0, sizeof *ud);
64 	if (ch >= 0xc2 && ch <= 0xdf)
65 		ud->size = 2;
66 	else if (ch >= 0xe0 && ch <= 0xef)
67 		ud->size = 3;
68 	else if (ch >= 0xf0 && ch <= 0xf4)
69 		ud->size = 4;
70 	else
71 		return (UTF8_ERROR);
72 	utf8_append(ud, ch);
73 	return (UTF8_MORE);
74 }
75 
76 /* Append character to UTF-8, closing if finished. */
77 enum utf8_state
78 utf8_append(struct utf8_data *ud, u_char ch)
79 {
80 	wchar_t	wc;
81 	int	width;
82 
83 	if (ud->have >= ud->size)
84 		fatalx("UTF-8 character overflow");
85 	if (ud->size > sizeof ud->data)
86 		fatalx("UTF-8 character size too large");
87 
88 	if (ud->have != 0 && (ch & 0xc0) != 0x80)
89 		ud->width = 0xff;
90 
91 	ud->data[ud->have++] = ch;
92 	if (ud->have != ud->size)
93 		return (UTF8_MORE);
94 
95 	if (ud->width == 0xff)
96 		return (UTF8_ERROR);
97 
98 	if (utf8_combine(ud, &wc) != UTF8_DONE)
99 		return (UTF8_ERROR);
100 	if ((width = utf8_width(wc)) < 0)
101 		return (UTF8_ERROR);
102 	ud->width = width;
103 
104 	return (UTF8_DONE);
105 }
106 
107 /* Get width of Unicode character. */
108 static int
109 utf8_width(wchar_t wc)
110 {
111 	int	width;
112 
113 	width = wcwidth(wc);
114 	if (width < 0 || width > 0xff) {
115 		log_debug("Unicode %04lx, wcwidth() %d", (long)wc, width);
116 		return (-1);
117 	}
118 	return (width);
119 }
120 
121 /* Combine UTF-8 into Unicode. */
122 enum utf8_state
123 utf8_combine(const struct utf8_data *ud, wchar_t *wc)
124 {
125 	switch (mbtowc(wc, ud->data, ud->size)) {
126 	case -1:
127 		log_debug("UTF-8 %.*s, mbtowc() %d", (int)ud->size, ud->data,
128 		    errno);
129 		mbtowc(NULL, NULL, MB_CUR_MAX);
130 		return (UTF8_ERROR);
131 	case 0:
132 		return (UTF8_ERROR);
133 	default:
134 		return (UTF8_DONE);
135 	}
136 }
137 
138 /* Split Unicode into UTF-8. */
139 enum utf8_state
140 utf8_split(wchar_t wc, struct utf8_data *ud)
141 {
142 	char	s[MB_LEN_MAX];
143 	int	slen;
144 
145 	slen = wctomb(s, wc);
146 	if (slen <= 0 || slen > (int)sizeof ud->data)
147 		return (UTF8_ERROR);
148 
149 	memcpy(ud->data, s, slen);
150 	ud->size = slen;
151 
152 	ud->width = utf8_width(wc);
153 	return (UTF8_DONE);
154 }
155 
156 /*
157  * Encode len characters from src into dst, which is guaranteed to have four
158  * bytes available for each character from src (for \abc or UTF-8) plus space
159  * for \0.
160  */
161 int
162 utf8_strvis(char *dst, const char *src, size_t len, int flag)
163 {
164 	struct utf8_data	 ud;
165 	const char		*start, *end;
166 	enum utf8_state		 more;
167 	size_t			 i;
168 
169 	start = dst;
170 	end = src + len;
171 
172 	while (src < end) {
173 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
174 			while (++src < end && more == UTF8_MORE)
175 				more = utf8_append(&ud, *src);
176 			if (more == UTF8_DONE) {
177 				/* UTF-8 character finished. */
178 				for (i = 0; i < ud.size; i++)
179 					*dst++ = ud.data[i];
180 				continue;
181 			}
182 			/* Not a complete, valid UTF-8 character. */
183 			src -= ud.have;
184 		}
185 		if (src < end - 1)
186 			dst = vis(dst, src[0], flag, src[1]);
187 		else if (src < end)
188 			dst = vis(dst, src[0], flag, '\0');
189 		src++;
190 	}
191 
192 	*dst = '\0';
193 	return (dst - start);
194 }
195 
196 /* Same as utf8_strvis but allocate the buffer. */
197 int
198 utf8_stravis(char **dst, const char *src, int flag)
199 {
200 	char	*buf;
201 	int	 len;
202 
203 	buf = xreallocarray(NULL, 4, strlen(src) + 1);
204 	len = utf8_strvis(buf, src, strlen(src), flag);
205 
206 	*dst = xrealloc(buf, len + 1);
207 	return (len);
208 }
209 
210 /* Does this string contain anything that isn't valid UTF-8? */
211 int
212 utf8_isvalid(const char *s)
213 {
214 	struct utf8_data	 ud;
215 	const char		*end;
216 	enum utf8_state		 more;
217 
218 	end = s + strlen(s);
219 	while (s < end) {
220 		if ((more = utf8_open(&ud, *s)) == UTF8_MORE) {
221 			while (++s < end && more == UTF8_MORE)
222 				more = utf8_append(&ud, *s);
223 			if (more == UTF8_DONE)
224 				continue;
225 			return (0);
226 		}
227 		if (*s < 0x20 || *s > 0x7e)
228 			return (0);
229 		s++;
230 	}
231 	return (1);
232 }
233 
234 /*
235  * Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
236  * the returned string. Anything not valid printable ASCII or UTF-8 is
237  * stripped.
238  */
239 char *
240 utf8_sanitize(const char *src)
241 {
242 	char			*dst;
243 	size_t			 n;
244 	enum utf8_state		 more;
245 	struct utf8_data	 ud;
246 	u_int			 i;
247 
248 	dst = NULL;
249 
250 	n = 0;
251 	while (*src != '\0') {
252 		dst = xreallocarray(dst, n + 1, sizeof *dst);
253 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
254 			while (*++src != '\0' && more == UTF8_MORE)
255 				more = utf8_append(&ud, *src);
256 			if (more == UTF8_DONE) {
257 				dst = xreallocarray(dst, n + ud.width,
258 				    sizeof *dst);
259 				for (i = 0; i < ud.width; i++)
260 					dst[n++] = '_';
261 				continue;
262 			}
263 			src -= ud.have;
264 		}
265 		if (*src > 0x1f && *src < 0x7f)
266 			dst[n++] = *src;
267 		else
268 			dst[n++] = '_';
269 		src++;
270 	}
271 
272 	dst = xreallocarray(dst, n + 1, sizeof *dst);
273 	dst[n] = '\0';
274 	return (dst);
275 }
276 
277 /* Get UTF-8 buffer length. */
278 size_t
279 utf8_strlen(const struct utf8_data *s)
280 {
281 	size_t	i;
282 
283 	for (i = 0; s[i].size != 0; i++)
284 		/* nothing */;
285 	return (i);
286 }
287 
288 /* Get UTF-8 string width. */
289 u_int
290 utf8_strwidth(const struct utf8_data *s, ssize_t n)
291 {
292 	ssize_t	i;
293 	u_int	width;
294 
295 	width = 0;
296 	for (i = 0; s[i].size != 0; i++) {
297 		if (n != -1 && n == i)
298 			break;
299 		width += s[i].width;
300 	}
301 	return (width);
302 }
303 
304 /*
305  * Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
306  * Caller frees.
307  */
308 struct utf8_data *
309 utf8_fromcstr(const char *src)
310 {
311 	struct utf8_data	*dst;
312 	size_t			 n;
313 	enum utf8_state		 more;
314 
315 	dst = NULL;
316 
317 	n = 0;
318 	while (*src != '\0') {
319 		dst = xreallocarray(dst, n + 1, sizeof *dst);
320 		if ((more = utf8_open(&dst[n], *src)) == UTF8_MORE) {
321 			while (*++src != '\0' && more == UTF8_MORE)
322 				more = utf8_append(&dst[n], *src);
323 			if (more == UTF8_DONE) {
324 				n++;
325 				continue;
326 			}
327 			src -= dst[n].have;
328 		}
329 		utf8_set(&dst[n], *src);
330 		n++;
331 		src++;
332 	}
333 
334 	dst = xreallocarray(dst, n + 1, sizeof *dst);
335 	dst[n].size = 0;
336 	return (dst);
337 }
338 
339 /* Convert from a buffer of UTF-8 characters into a string. Caller frees. */
340 char *
341 utf8_tocstr(struct utf8_data *src)
342 {
343 	char	*dst;
344 	size_t	 n;
345 
346 	dst = NULL;
347 
348 	n = 0;
349 	for(; src->size != 0; src++) {
350 		dst = xreallocarray(dst, n + src->size, 1);
351 		memcpy(dst + n, src->data, src->size);
352 		n += src->size;
353 	}
354 
355 	dst = xreallocarray(dst, n + 1, 1);
356 	dst[n] = '\0';
357 	return (dst);
358 }
359 
360 /* Get width of UTF-8 string. */
361 u_int
362 utf8_cstrwidth(const char *s)
363 {
364 	struct utf8_data	tmp;
365 	u_int			width;
366 	enum utf8_state		more;
367 
368 	width = 0;
369 	while (*s != '\0') {
370 		if ((more = utf8_open(&tmp, *s)) == UTF8_MORE) {
371 			while (*++s != '\0' && more == UTF8_MORE)
372 				more = utf8_append(&tmp, *s);
373 			if (more == UTF8_DONE) {
374 				width += tmp.width;
375 				continue;
376 			}
377 			s -= tmp.have;
378 		}
379 		if (*s > 0x1f && *s != 0x7f)
380 			width++;
381 		s++;
382 	}
383 	return (width);
384 }
385 
386 /* Pad UTF-8 string to width. Caller frees. */
387 char *
388 utf8_padcstr(const char *s, u_int width)
389 {
390 	size_t	 slen;
391 	char	*out;
392 	u_int	  n, i;
393 
394 	n = utf8_cstrwidth(s);
395 	if (n >= width)
396 		return (xstrdup(s));
397 
398 	slen = strlen(s);
399 	out = xmalloc(slen + 1 + (width - n));
400 	memcpy(out, s, slen);
401 	for (i = n; i < width; i++)
402 		out[slen++] = ' ';
403 	out[slen] = '\0';
404 	return (out);
405 }
406