xref: /dragonfly/contrib/less/charset.c (revision e0f238eda64c20d98364903e0c003825fd0b66dd)
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