xref: /dragonfly/contrib/less/charset.c (revision e433da38)
1 /*
2  * Copyright (C) 1984-2024  Mark Nudelman
3  *
4  * You may distribute under the terms of either the GNU General Public
5  * License or the Less License, as specified in the README file.
6  *
7  * For more information, see the README file.
8  */
9 
10 
11 /*
12  * Functions to define the character set
13  * and do things specific to the character set.
14  */
15 
16 #include "less.h"
17 #if HAVE_LOCALE
18 #include <locale.h>
19 #include <ctype.h>
20 #include <langinfo.h>
21 #endif
22 
23 #include "charset.h"
24 #include "xbuf.h"
25 
26 #if MSDOS_COMPILER==WIN32C
27 #define WIN32_LEAN_AND_MEAN
28 #include <windows.h>
29 #endif
30 
31 extern int bs_mode;
32 
33 public int utf_mode = 0;
34 
35 /*
36  * Predefined character sets,
37  * selected by the LESSCHARSET environment variable.
38  */
39 struct charset {
40 	char *name;
41 	int *p_flag;
42 	char *desc;
43 } charsets[] = {
44 		{ "ascii",              NULL,       "8bcccbcc18b95.b" },
45 		{ "utf-8",              &utf_mode,  "8bcccbcc18b95.b126.bb" },
46 		{ "iso8859",            NULL,       "8bcccbcc18b95.33b." },
47 		{ "latin3",             NULL,       "8bcccbcc18b95.33b5.b8.b15.b4.b12.b18.b12.b." },
48 		{ "arabic",             NULL,       "8bcccbcc18b95.33b.3b.7b2.13b.3b.b26.5b19.b" },
49 		{ "greek",              NULL,       "8bcccbcc18b95.33b4.2b4.b3.b35.b44.b" },
50 		{ "greek2005",          NULL,       "8bcccbcc18b95.33b14.b35.b44.b" },
51 		{ "hebrew",             NULL,       "8bcccbcc18b95.33b.b29.32b28.2b2.b" },
52 		{ "koi8-r",             NULL,       "8bcccbcc18b95.b." },
53 		{ "KOI8-T",             NULL,       "8bcccbcc18b95.b8.b6.b8.b.b.5b7.3b4.b4.b3.b.b.3b." },
54 		{ "georgianps",         NULL,       "8bcccbcc18b95.3b11.4b12.2b." },
55 		{ "tcvn",               NULL,       "b..b...bcccbccbbb7.8b95.b48.5b." },
56 		{ "TIS-620",            NULL,       "8bcccbcc18b95.b.4b.11b7.8b." },
57 		{ "next",               NULL,       "8bcccbcc18b95.bb125.bb" },
58 		{ "dos",                NULL,       "8bcccbcc12bc5b95.b." },
59 		{ "windows-1251",       NULL,       "8bcccbcc12bc5b95.b24.b." },
60 		{ "windows-1252",       NULL,       "8bcccbcc12bc5b95.b.b11.b.2b12.b." },
61 		{ "windows-1255",       NULL,       "8bcccbcc12bc5b95.b.b8.b.5b9.b.4b." },
62 		{ "ebcdic",             NULL,       "5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b." },
63 		{ "IBM-1047",           NULL,       "4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc191.b" },
64 		{ NULL, NULL, NULL }
65 };
66 
67 /*
68  * Support "locale charmap"/nl_langinfo(CODESET) values, as well as others.
69  */
70 struct cs_alias {
71 	char *name;
72 	char *oname;
73 } cs_aliases[] = {
74 	{ "UTF-8",              "utf-8" },
75 	{ "utf8",               "utf-8" },
76 	{ "UTF8",               "utf-8" },
77 	{ "ANSI_X3.4-1968",     "ascii" },
78 	{ "US-ASCII",           "ascii" },
79 	{ "latin1",             "iso8859" },
80 	{ "ISO-8859-1",         "iso8859" },
81 	{ "latin9",             "iso8859" },
82 	{ "ISO-8859-15",        "iso8859" },
83 	{ "latin2",             "iso8859" },
84 	{ "ISO-8859-2",         "iso8859" },
85 	{ "ISO-8859-3",         "latin3" },
86 	{ "latin4",             "iso8859" },
87 	{ "ISO-8859-4",         "iso8859" },
88 	{ "cyrillic",           "iso8859" },
89 	{ "ISO-8859-5",         "iso8859" },
90 	{ "ISO-8859-6",         "arabic" },
91 	{ "ISO-8859-7",         "greek" },
92 	{ "IBM9005",            "greek2005" },
93 	{ "ISO-8859-8",         "hebrew" },
94 	{ "latin5",             "iso8859" },
95 	{ "ISO-8859-9",         "iso8859" },
96 	{ "latin6",             "iso8859" },
97 	{ "ISO-8859-10",        "iso8859" },
98 	{ "latin7",             "iso8859" },
99 	{ "ISO-8859-13",        "iso8859" },
100 	{ "latin8",             "iso8859" },
101 	{ "ISO-8859-14",        "iso8859" },
102 	{ "latin10",            "iso8859" },
103 	{ "ISO-8859-16",        "iso8859" },
104 	{ "IBM437",             "dos" },
105 	{ "EBCDIC-US",          "ebcdic" },
106 	{ "IBM1047",            "IBM-1047" },
107 	{ "KOI8-R",             "koi8-r" },
108 	{ "KOI8-U",             "koi8-r" },
109 	{ "GEORGIAN-PS",        "georgianps" },
110 	{ "TCVN5712-1",         "tcvn" },
111 	{ "NEXTSTEP",           "next" },
112 	{ "windows",            "windows-1252" }, /* backward compatibility */
113 	{ "CP1251",             "windows-1251" },
114 	{ "CP1252",             "windows-1252" },
115 	{ "CP1255",             "windows-1255" },
116 	{ NULL, NULL }
117 };
118 
119 #define IS_BINARY_CHAR  01
120 #define IS_CONTROL_CHAR 02
121 
122 static char chardef[256];
123 static constant char *binfmt = NULL;
124 static constant char *utfbinfmt = NULL;
125 public int binattr = AT_STANDOUT|AT_COLOR_BIN;
126 
127 static struct xbuffer user_wide_array;
128 static struct xbuffer user_ubin_array;
129 static struct xbuffer user_compose_array;
130 static struct xbuffer user_prt_array;
131 static struct wchar_range_table user_wide_table;
132 static struct wchar_range_table user_ubin_table;
133 static struct wchar_range_table user_compose_table;
134 static struct wchar_range_table user_prt_table;
135 
136 /*
137  * Set a wchar_range_table to the table in an xbuffer.
138  */
wchar_range_table_set(struct wchar_range_table * tbl,struct xbuffer * arr)139 static void wchar_range_table_set(struct wchar_range_table *tbl, struct xbuffer *arr)
140 {
141 	tbl->table = (struct wchar_range *) arr->data;
142 	tbl->count = (unsigned int) (arr->end / sizeof(struct wchar_range));
143 }
144 
145 /*
146  * Skip over a "U" or "U+" prefix before a hex codepoint.
147  */
skip_uprefix(constant char * s)148 static constant char * skip_uprefix(constant char *s)
149 {
150 	if (*s == 'U' || *s == 'u')
151 		if (*++s == '+') ++s;
152 	return s;
153 }
154 
155 /*
156  * Parse a dash-separated range of hex values.
157  */
wchar_range_get(constant char ** ss,struct wchar_range * range)158 static void wchar_range_get(constant char **ss, struct wchar_range *range)
159 {
160 	constant char *s = skip_uprefix(*ss);
161 	range->first = lstrtoulc(s, &s, 16);
162 	if (s[0] == '-')
163 	{
164 		s = skip_uprefix(&s[1]);
165 		range->last = lstrtoulc(s, &s, 16);
166 	} else
167 	{
168 		range->last = range->first;
169 	}
170 	*ss = s;
171 }
172 
173 /*
174  * Parse the LESSUTFCHARDEF variable.
175  */
ichardef_utf(constant char * s)176 static void ichardef_utf(constant char *s)
177 {
178 	xbuf_init(&user_wide_array);
179 	xbuf_init(&user_ubin_array);
180 	xbuf_init(&user_compose_array);
181 	xbuf_init(&user_prt_array);
182 
183 	if (s != NULL)
184 	{
185 		while (s[0] != '\0')
186 		{
187 			struct wchar_range range;
188 			wchar_range_get(&s, &range);
189 			if (range.last == 0)
190 			{
191 				error("invalid hex number(s) in LESSUTFCHARDEF", NULL_PARG);
192 				quit(QUIT_ERROR);
193 			}
194 			if (*s++ != ':')
195 			{
196 				error("missing colon in LESSUTFCHARDEF", NULL_PARG);
197 				quit(QUIT_ERROR);
198 			}
199 			switch (*s++)
200 			{
201 			case 'b':
202 				xbuf_add_data(&user_ubin_array, (unsigned char *) &range, sizeof(range));
203 				break;
204 			case 'c':
205 				xbuf_add_data(&user_compose_array, (unsigned char *) &range, sizeof(range));
206 				break;
207 			case 'w':
208 				xbuf_add_data(&user_wide_array, (unsigned char *) &range, sizeof(range));
209 				xbuf_add_data(&user_prt_array, (unsigned char *) &range, sizeof(range));
210 				break;
211 			case 'p': case '.':
212 				xbuf_add_data(&user_prt_array, (unsigned char *) &range, sizeof(range));
213 				break;
214 			case '\0':
215 				s--;
216 				break;
217 			default:
218 				/* Ignore unknown character attribute. */
219 				break;
220 			}
221 			if (s[0] == ',') ++s;
222 		}
223 	}
224 	wchar_range_table_set(&user_wide_table, &user_wide_array);
225 	wchar_range_table_set(&user_ubin_table, &user_ubin_array);
226 	wchar_range_table_set(&user_compose_table, &user_compose_array);
227 	wchar_range_table_set(&user_prt_table, &user_prt_array);
228 }
229 
230 /*
231  * Define a charset, given a description string.
232  * The string consists of 256 letters,
233  * one for each character in the charset.
234  * If the string is shorter than 256 letters, missing letters
235  * are taken to be identical to the last one.
236  * A decimal number followed by a letter is taken to be a
237  * repetition of the letter.
238  *
239  * Each letter is one of:
240  *      . normal character
241  *      b binary character
242  *      c control character
243  */
ichardef(constant char * s)244 static void ichardef(constant char *s)
245 {
246 	char *cp;
247 	int n;
248 	char v;
249 
250 	n = 0;
251 	v = 0;
252 	cp = chardef;
253 	while (*s != '\0')
254 	{
255 		switch (*s++)
256 		{
257 		case '.':
258 			v = 0;
259 			break;
260 		case 'c':
261 			v = IS_CONTROL_CHAR;
262 			break;
263 		case 'b':
264 			v = IS_BINARY_CHAR|IS_CONTROL_CHAR;
265 			break;
266 
267 		case '0': case '1': case '2': case '3': case '4':
268 		case '5': case '6': case '7': case '8': case '9':
269 			if (ckd_mul(&n, n, 10) || ckd_add(&n, n, s[-1] - '0'))
270 				goto invalid_chardef;
271 			continue;
272 
273 		default:
274 		invalid_chardef:
275 			error("invalid chardef", NULL_PARG);
276 			quit(QUIT_ERROR);
277 			/*NOTREACHED*/
278 		}
279 
280 		do
281 		{
282 			if (cp >= chardef + sizeof(chardef))
283 			{
284 				error("chardef longer than 256", NULL_PARG);
285 				quit(QUIT_ERROR);
286 				/*NOTREACHED*/
287 			}
288 			*cp++ = v;
289 		} while (--n > 0);
290 		n = 0;
291 	}
292 
293 	while (cp < chardef + sizeof(chardef))
294 		*cp++ = v;
295 }
296 
297 /*
298  * Define a charset, given a charset name.
299  * The valid charset names are listed in the "charsets" array.
300  */
icharset(constant char * name,int no_error)301 static int icharset(constant char *name, int no_error)
302 {
303 	struct charset *p;
304 	struct cs_alias *a;
305 
306 	if (name == NULL || *name == '\0')
307 		return (0);
308 
309 	/* First see if the name is an alias. */
310 	for (a = cs_aliases;  a->name != NULL;  a++)
311 	{
312 		if (strcmp(name, a->name) == 0)
313 		{
314 			name = a->oname;
315 			break;
316 		}
317 	}
318 
319 	for (p = charsets;  p->name != NULL;  p++)
320 	{
321 		if (strcmp(name, p->name) == 0)
322 		{
323 			ichardef(p->desc);
324 			if (p->p_flag != NULL)
325 			{
326 #if MSDOS_COMPILER==WIN32C
327 				*(p->p_flag) = 1 + (GetConsoleOutputCP() != CP_UTF8);
328 #else
329 				*(p->p_flag) = 1;
330 #endif
331 			}
332 			return (1);
333 		}
334 	}
335 
336 	if (!no_error) {
337 		error("invalid charset name", NULL_PARG);
338 		quit(QUIT_ERROR);
339 	}
340 	return (0);
341 }
342 
343 #if HAVE_LOCALE
344 /*
345  * Define a charset, given a locale name.
346  */
ilocale(void)347 static void ilocale(void)
348 {
349 	int c;
350 
351 	for (c = 0;  c < (int) sizeof(chardef);  c++)
352 	{
353 		if (isprint(c))
354 			chardef[c] = 0;
355 		else if (iscntrl(c))
356 			chardef[c] = IS_CONTROL_CHAR;
357 		else
358 			chardef[c] = IS_BINARY_CHAR|IS_CONTROL_CHAR;
359 	}
360 }
361 #endif
362 
363 /*
364  * Define the printing format for control (or binary utf) chars.
365  */
setfmt(constant char * s,constant char ** fmtvarptr,int * attrptr,constant char * default_fmt,lbool for_printf)366 public void setfmt(constant char *s, constant char **fmtvarptr, int *attrptr, constant char *default_fmt, lbool for_printf)
367 {
368 	if (s == NULL || *s == '\0')
369 		s = default_fmt;
370 	else if (for_printf &&
371 	    ((*s == '*' && (s[1] == '\0' || s[2] == '\0' || strchr(s + 2, 'n'))) ||
372 	     (*s != '*' && strchr(s, 'n'))))
373 		/* %n is evil */
374 		s = default_fmt;
375 
376 	/*
377 	 * Select the attributes if it starts with "*".
378 	 */
379 	if (*s == '*' && s[1] != '\0')
380 	{
381 		switch (s[1])
382 		{
383 		case 'd':  *attrptr = AT_BOLD;      break;
384 		case 'k':  *attrptr = AT_BLINK;     break;
385 		case 's':  *attrptr = AT_STANDOUT;  break;
386 		case 'u':  *attrptr = AT_UNDERLINE; break;
387 		default:   *attrptr = AT_NORMAL;    break;
388 		}
389 		s += 2;
390 	}
391 	*fmtvarptr = s;
392 }
393 
394 /*
395  *
396  */
set_charset(void)397 static void set_charset(void)
398 {
399 	constant char *s;
400 
401 	ichardef_utf(lgetenv("LESSUTFCHARDEF"));
402 
403 	/*
404 	 * See if environment variable LESSCHARSET is defined.
405 	 */
406 	s = lgetenv("LESSCHARSET");
407 	if (icharset(s, 0))
408 		return;
409 
410 	/*
411 	 * LESSCHARSET is not defined: try LESSCHARDEF.
412 	 */
413 	s = lgetenv("LESSCHARDEF");
414 	if (!isnullenv(s))
415 	{
416 		ichardef(s);
417 		return;
418 	}
419 
420 #if HAVE_LOCALE
421 #ifdef CODESET
422 	/*
423 	 * Try using the codeset name as the charset name.
424 	 */
425 	s = nl_langinfo(CODESET);
426 	if (icharset(s, 1))
427 		return;
428 #endif
429 #endif
430 
431 #if HAVE_STRSTR
432 	/*
433 	 * Check whether LC_ALL, LC_CTYPE or LANG look like UTF-8 is used.
434 	 */
435 	if ((s = lgetenv("LC_ALL")) != NULL ||
436 	    (s = lgetenv("LC_CTYPE")) != NULL ||
437 	    (s = lgetenv("LANG")) != NULL)
438 	{
439 		if (   strstr(s, "UTF-8") != NULL || strstr(s, "utf-8") != NULL
440 		    || strstr(s, "UTF8")  != NULL || strstr(s, "utf8")  != NULL)
441 			if (icharset("utf-8", 1))
442 				return;
443 	}
444 #endif
445 
446 #if HAVE_LOCALE
447 	/*
448 	 * Get character definitions from locale functions,
449 	 * rather than from predefined charset entry.
450 	 */
451 	ilocale();
452 #else
453 #if MSDOS_COMPILER
454 #if MSDOS_COMPILER==WIN32C
455 	(void) icharset("utf-8", 1);
456 #else
457 	(void) icharset("dos", 1);
458 #endif
459 #else
460 	(void) icharset("utf-8", 1);
461 #endif
462 #endif
463 }
464 
465 /*
466  * Initialize charset data structures.
467  */
init_charset(void)468 public void init_charset(void)
469 {
470 	constant char *s;
471 
472 #if HAVE_LOCALE
473 	setlocale(LC_ALL, "");
474 #endif
475 
476 	set_charset();
477 
478 	s = lgetenv("LESSBINFMT");
479 	setfmt(s, &binfmt, &binattr, "*s<%02X>", TRUE);
480 
481 	s = lgetenv("LESSUTFBINFMT");
482 	setfmt(s, &utfbinfmt, &binattr, "<U+%04lX>", TRUE);
483 }
484 
485 /*
486  * Is a given character a "binary" character?
487  */
binary_char(LWCHAR c)488 public lbool binary_char(LWCHAR c)
489 {
490 	if (utf_mode)
491 		return (is_ubin_char(c));
492 	if (c >= sizeof(chardef))
493 		return TRUE;
494 	return ((chardef[c] & IS_BINARY_CHAR) != 0);
495 }
496 
497 /*
498  * Is a given character a "control" character?
499  */
control_char(LWCHAR c)500 public lbool control_char(LWCHAR c)
501 {
502 	if (c >= sizeof(chardef))
503 		return TRUE;
504 	return (chardef[c] & IS_CONTROL_CHAR);
505 }
506 
507 /*
508  * Return the printable form of a character.
509  * For example, in the "ascii" charset '\3' is printed as "^C".
510  */
prchar(LWCHAR c)511 public constant char * prchar(LWCHAR c)
512 {
513 	/* {{ Fixed buffer size means LESSBINFMT etc can be truncated. }} */
514 	static char buf[MAX_PRCHAR_LEN+1];
515 
516 	c &= 0377; /*{{type-issue}}*/
517 	if ((c < 128 || !utf_mode) && !control_char(c))
518 		SNPRINTF1(buf, sizeof(buf), "%c", (int) c);
519 	else if (c == ESC)
520 		strcpy(buf, "ESC");
521 #if IS_EBCDIC_HOST
522 	else if (!binary_char(c) && c < 64)
523 		SNPRINTF1(buf, sizeof(buf), "^%c",
524 		/*
525 		 * This array roughly inverts CONTROL() #defined in less.h,
526 		 * and should be kept in sync with CONTROL() and IBM-1047.
527 		 */
528 		"@ABC.I.?...KLMNO"
529 		"PQRS.JH.XY.."
530 		"\\]^_"
531 		"......W[.....EFG"
532 		"..V....D....TU.Z"[c]);
533 #else
534 	else if (c < 128 && !control_char(c ^ 0100))
535 		SNPRINTF1(buf, sizeof(buf), "^%c", (int) (c ^ 0100));
536 #endif
537 	else
538 		SNPRINTF1(buf, sizeof(buf), binfmt, c);
539 	return (buf);
540 }
541 
542 /*
543  * Return the printable form of a UTF-8 character.
544  */
prutfchar(LWCHAR ch)545 public constant char * prutfchar(LWCHAR ch)
546 {
547 	static char buf[MAX_PRCHAR_LEN+1];
548 
549 	if (ch == ESC)
550 		strcpy(buf, "ESC");
551 	else if (ch < 128 && control_char(ch))
552 	{
553 		if (!control_char(ch ^ 0100))
554 			SNPRINTF1(buf, sizeof(buf), "^%c", ((char) ch) ^ 0100);
555 		else
556 			SNPRINTF1(buf, sizeof(buf), binfmt, (char) ch);
557 	} else if (is_ubin_char(ch))
558 	{
559 		SNPRINTF1(buf, sizeof(buf), utfbinfmt, ch);
560 	} else
561 	{
562 		char *p = buf;
563 		if (ch >= 0x80000000)
564 			ch = 0xFFFD; /* REPLACEMENT CHARACTER */
565 		put_wchar(&p, ch);
566 		*p = '\0';
567 	}
568 	return (buf);
569 }
570 
571 /*
572  * Get the length of a UTF-8 character in bytes.
573  */
utf_len(char ch)574 public int utf_len(char ch)
575 {
576 	if ((ch & 0x80) == 0)
577 		return 1;
578 	if ((ch & 0xE0) == 0xC0)
579 		return 2;
580 	if ((ch & 0xF0) == 0xE0)
581 		return 3;
582 	if ((ch & 0xF8) == 0xF0)
583 		return 4;
584 #if 0
585 	if ((ch & 0xFC) == 0xF8)
586 		return 5;
587 	if ((ch & 0xFE) == 0xFC)
588 		return 6;
589 #endif
590 	/* Invalid UTF-8 encoding. */
591 	return 1;
592 }
593 
594 /*
595  * Does the parameter point to the lead byte of a well-formed UTF-8 character?
596  */
is_utf8_well_formed(constant char * ss,int slen)597 public lbool is_utf8_well_formed(constant char *ss, int slen)
598 {
599 	int i;
600 	int len;
601 	unsigned char s0 = (unsigned char) ss[0];
602 
603 	if (IS_UTF8_INVALID(s0))
604 		return (FALSE);
605 
606 	len = utf_len(ss[0]);
607 	if (len > slen)
608 		return (FALSE);
609 	if (len == 1)
610 		return (TRUE);
611 	if (len == 2)
612 	{
613 		if (s0 < 0xC2)
614 			return (FALSE);
615 	} else
616 	{
617 		unsigned char mask = (unsigned char) (~((1 << (8-len)) - 1));
618 		if (s0 == mask && (ss[1] & mask) == 0x80)
619 			return (FALSE);
620 	}
621 
622 	for (i = 1;  i < len;  i++)
623 		if (!IS_UTF8_TRAIL(ss[i]))
624 			return (FALSE);
625 	return (TRUE);
626 }
627 
628 /*
629  * Skip bytes until a UTF-8 lead byte (11xxxxxx) or ASCII byte (0xxxxxxx) is found.
630  */
utf_skip_to_lead(constant char ** pp,constant char * limit)631 public void utf_skip_to_lead(constant char **pp, constant char *limit)
632 {
633 	do {
634 		++(*pp);
635 	} while (*pp < limit && !IS_UTF8_LEAD((*pp)[0] & 0377) && !IS_ASCII_OCTET((*pp)[0]));
636 }
637 
638 
639 /*
640  * Get the value of a UTF-8 character.
641  */
get_wchar(constant char * sp)642 public LWCHAR get_wchar(constant char *sp)
643 {
644 	constant unsigned char *p = (constant unsigned char *) sp;
645 	switch (utf_len(sp[0]))
646 	{
647 	case 1:
648 	default:
649 		/* 0xxxxxxx */
650 		return (LWCHAR)
651 			(p[0] & 0xFF);
652 	case 2:
653 		/* 110xxxxx 10xxxxxx */
654 		return (LWCHAR) (
655 			((p[0] & 0x1F) << 6) |
656 			(p[1] & 0x3F));
657 	case 3:
658 		/* 1110xxxx 10xxxxxx 10xxxxxx */
659 		return (LWCHAR) (
660 			((p[0] & 0x0F) << 12) |
661 			((p[1] & 0x3F) << 6) |
662 			(p[2] & 0x3F));
663 	case 4:
664 		/* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
665 		return (LWCHAR) (
666 			((p[0] & 0x07) << 18) |
667 			((p[1] & 0x3F) << 12) |
668 			((p[2] & 0x3F) << 6) |
669 			(p[3] & 0x3F));
670 #if 0
671 	case 5:
672 		/* 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */
673 		return (LWCHAR) (
674 			((p[0] & 0x03) << 24) |
675 			((p[1] & 0x3F) << 18) |
676 			((p[2] & 0x3F) << 12) |
677 			((p[3] & 0x3F) << 6) |
678 			(p[4] & 0x3F));
679 	case 6:
680 		/* 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */
681 		return (LWCHAR) (
682 			((p[0] & 0x01) << 30) |
683 			((p[1] & 0x3F) << 24) |
684 			((p[2] & 0x3F) << 18) |
685 			((p[3] & 0x3F) << 12) |
686 			((p[4] & 0x3F) << 6) |
687 			(p[5] & 0x3F));
688 #endif
689 	}
690 }
691 
692 /*
693  * Store a character into a UTF-8 string.
694  */
put_wchar(mutable char ** pp,LWCHAR ch)695 public void put_wchar(mutable char **pp, LWCHAR ch)
696 {
697 	if (!utf_mode || ch < 0x80)
698 	{
699 		/* 0xxxxxxx */
700 		*(*pp)++ = (char) ch;
701 	} else if (ch < 0x800)
702 	{
703 		/* 110xxxxx 10xxxxxx */
704 		*(*pp)++ = (char) (0xC0 | ((ch >> 6) & 0x1F));
705 		*(*pp)++ = (char) (0x80 | (ch & 0x3F));
706 	} else if (ch < 0x10000)
707 	{
708 		/* 1110xxxx 10xxxxxx 10xxxxxx */
709 		*(*pp)++ = (char) (0xE0 | ((ch >> 12) & 0x0F));
710 		*(*pp)++ = (char) (0x80 | ((ch >> 6) & 0x3F));
711 		*(*pp)++ = (char) (0x80 | (ch & 0x3F));
712 	} else if (ch < 0x200000)
713 	{
714 		/* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
715 		*(*pp)++ = (char) (0xF0 | ((ch >> 18) & 0x07));
716 		*(*pp)++ = (char) (0x80 | ((ch >> 12) & 0x3F));
717 		*(*pp)++ = (char) (0x80 | ((ch >> 6) & 0x3F));
718 		*(*pp)++ = (char) (0x80 | (ch & 0x3F));
719 #if 0
720 	} else if (ch < 0x4000000)
721 	{
722 		/* 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */
723 		*(*pp)++ = (char) (0xF0 | ((ch >> 24) & 0x03));
724 		*(*pp)++ = (char) (0x80 | ((ch >> 18) & 0x3F));
725 		*(*pp)++ = (char) (0x80 | ((ch >> 12) & 0x3F));
726 		*(*pp)++ = (char) (0x80 | ((ch >> 6) & 0x3F));
727 		*(*pp)++ = (char) (0x80 | (ch & 0x3F));
728 	} else
729 	{
730 		/* 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */
731 		*(*pp)++ = (char) (0xF0 | ((ch >> 30) & 0x01));
732 		*(*pp)++ = (char) (0x80 | ((ch >> 24) & 0x3F));
733 		*(*pp)++ = (char) (0x80 | ((ch >> 18) & 0x3F));
734 		*(*pp)++ = (char) (0x80 | ((ch >> 12) & 0x3F));
735 		*(*pp)++ = (char) (0x80 | ((ch >> 6) & 0x3F));
736 		*(*pp)++ = (char) (0x80 | (ch & 0x3F));
737 #endif
738 	}
739 }
740 
741 /*
742  * Step forward or backward one character in a string.
743  */
step_charc(constant char ** pp,signed int dir,constant char * limit)744 public LWCHAR step_charc(constant char **pp, signed int dir, constant char *limit)
745 {
746 	LWCHAR ch;
747 	int len;
748 	constant char *p = *pp;
749 
750 	if (!utf_mode)
751 	{
752 		/* It's easy if chars are one byte. */
753 		if (dir > 0)
754 			ch = (LWCHAR) (unsigned char) ((p < limit) ? *p++ : 0);
755 		else
756 			ch = (LWCHAR) (unsigned char) ((p > limit) ? *--p : 0);
757 	} else if (dir > 0)
758 	{
759 		len = utf_len(*p);
760 		if (p + len > limit)
761 		{
762 			ch = 0;
763 			p = (char *) limit;
764 		} else
765 		{
766 			ch = get_wchar(p);
767 			p += len;
768 		}
769 	} else
770 	{
771 		while (p > limit && IS_UTF8_TRAIL(p[-1]))
772 			p--;
773 		if (p > limit)
774 			ch = get_wchar(--p);
775 		else
776 			ch = 0;
777 	}
778 	*pp = p;
779 	return ch;
780 }
781 
step_char(char ** pp,signed int dir,constant char * limit)782 public LWCHAR step_char(char **pp, signed int dir, constant char *limit)
783 {
784 	constant char *p = (constant char *) *pp;
785 	LWCHAR ch = step_charc(&p, dir, limit);
786 	*pp = (char *) p;
787 	return ch;
788 }
789 
790 /*
791  * Unicode characters data
792  * Actual data is in the generated *.uni files.
793  */
794 
795 #define DECLARE_RANGE_TABLE_START(name) \
796 	static struct wchar_range name##_array[] = {
797 #define DECLARE_RANGE_TABLE_END(name) \
798 	}; struct wchar_range_table name##_table = { name##_array, countof(name##_array) };
799 
800 DECLARE_RANGE_TABLE_START(compose)
801 #include "compose.uni"
802 DECLARE_RANGE_TABLE_END(compose)
803 
804 DECLARE_RANGE_TABLE_START(ubin)
805 #include "ubin.uni"
806 DECLARE_RANGE_TABLE_END(ubin)
807 
808 DECLARE_RANGE_TABLE_START(wide)
809 #include "wide.uni"
810 DECLARE_RANGE_TABLE_END(wide)
811 
812 DECLARE_RANGE_TABLE_START(fmt)
813 #include "fmt.uni"
814 DECLARE_RANGE_TABLE_END(fmt)
815 
816 /* comb_table is special pairs, not ranges. */
817 static struct wchar_range comb_table[] = {
818 	{0x0644,0x0622}, {0x0644,0x0623}, {0x0644,0x0625}, {0x0644,0x0627},
819 };
820 
821 
is_in_table(LWCHAR ch,struct wchar_range_table * table)822 static lbool is_in_table(LWCHAR ch, struct wchar_range_table *table)
823 {
824 	unsigned int hi;
825 	unsigned int lo;
826 
827 	/* Binary search in the table. */
828 	if (table->table == NULL || table->count == 0 || ch < table->table[0].first)
829 		return FALSE;
830 	lo = 0;
831 	hi = table->count - 1;
832 	while (lo <= hi)
833 	{
834 		unsigned int mid = (lo + hi) / 2;
835 		if (ch > table->table[mid].last)
836 			lo = mid + 1;
837 		else if (ch < table->table[mid].first)
838 			hi = mid - 1;
839 		else
840 			return TRUE;
841 	}
842 	return FALSE;
843 }
844 
845 /*
846  * Is a character a UTF-8 composing character?
847  * If a composing character follows any char, the two combine into one glyph.
848  */
is_composing_char(LWCHAR ch)849 public lbool is_composing_char(LWCHAR ch)
850 {
851 	if (is_in_table(ch, &user_prt_table)) return FALSE;
852 	return is_in_table(ch, &user_compose_table) ||
853 	       is_in_table(ch, &compose_table) ||
854 	       (bs_mode != BS_CONTROL && is_in_table(ch, &fmt_table));
855 }
856 
857 /*
858  * Should this UTF-8 character be treated as binary?
859  */
is_ubin_char(LWCHAR ch)860 public lbool is_ubin_char(LWCHAR ch)
861 {
862 	if (is_in_table(ch, &user_prt_table)) return FALSE;
863 	return is_in_table(ch, &user_ubin_table) ||
864 	       is_in_table(ch, &ubin_table) ||
865 	       (bs_mode == BS_CONTROL && is_in_table(ch, &fmt_table));
866 }
867 
868 /*
869  * Is this a double width UTF-8 character?
870  */
is_wide_char(LWCHAR ch)871 public lbool is_wide_char(LWCHAR ch)
872 {
873 	return is_in_table(ch, &user_wide_table) ||
874 	       is_in_table(ch, &wide_table);
875 }
876 
877 /*
878  * Is a character a UTF-8 combining character?
879  * A combining char acts like an ordinary char, but if it follows
880  * a specific char (not any char), the two combine into one glyph.
881  */
is_combining_char(LWCHAR ch1,LWCHAR ch2)882 public lbool is_combining_char(LWCHAR ch1, LWCHAR ch2)
883 {
884 	/* The table is small; use linear search. */
885 	int i;
886 	for (i = 0;  i < countof(comb_table);  i++)
887 	{
888 		if (ch1 == comb_table[i].first &&
889 		    ch2 == comb_table[i].last)
890 			return TRUE;
891 	}
892 	return FALSE;
893 }
894 
895