chars.c

   1 /*      $Id: chars.c,v 1.41 2011/05/14 17:54:42 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
   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 USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include "mandoc.h"
  29
  30 #define PRINT_HI         126
  31 #define PRINT_LO         32
  32
  33 struct  ln {
  34         struct ln        *next;
  35         const char       *code;
  36         const char       *ascii;
  37         int               unicode;
  38         int               type;
  39 #define CHARS_CHAR       (1 << 0)
  40 #define CHARS_STRING     (1 << 1)
  41 #define CHARS_BOTH       (CHARS_CHAR | CHARS_STRING)
  42 };
  43
  44 #define LINES_MAX         353
  45
  46 #define CHAR(in, ch, code) \
  47         { NULL, (in), (ch), (code), CHARS_CHAR },
  48 #define STRING(in, ch, code) \
  49         { NULL, (in), (ch), (code), CHARS_STRING },
  50 #define BOTH(in, ch, code) \
  51         { NULL, (in), (ch), (code), CHARS_BOTH },
  52
  53 #define CHAR_TBL_START    static struct ln lines[LINES_MAX] = {
  54 #define CHAR_TBL_END      };
  55
  56 #include "chars.in"
  57
  58 struct  mchars {
  59         struct ln       **htab;
  60 };
  61
  62 static  inline int        match(const struct ln *,
  63                                 const char *, size_t, int);
  64 static  const struct ln  *find(struct mchars *, const char *, size_t, int);
  65
  66 void
  67 mchars_free(struct mchars *arg)
  68 {
  69
  70         free(arg->htab);
  71         free(arg);
  72 }
  73
  74 struct mchars *
  75 mchars_alloc(void)
  76 {
  77         struct mchars    *tab;
  78         struct ln       **htab;
  79         struct ln        *pp;
  80         int               i, hash;
  81
  82         /*
  83          * Constructs a very basic chaining hashtable.  The hash routine
  84          * is simply the integral value of the first character.
  85          * Subsequent entries are chained in the order they're processed
  86          * (they're in-line re-ordered during lookup).
  87          */
  88
  89         tab = mandoc_malloc(sizeof(struct mchars));
  90         htab = mandoc_calloc(PRINT_HI - PRINT_LO + 1, sizeof(struct ln **));
  91
  92         for (i = 0; i < LINES_MAX; i++) {
  93                 hash = (int)lines[i].code[0] - PRINT_LO;
  94
  95                 if (NULL == (pp = htab[hash])) {
  96                         htab[hash] = &lines[i];
  97                         continue;
  98                 }
  99
 100                 for ( ; pp->next; pp = pp->next)
 101                         /* Scan ahead. */ ;
 102                 pp->next = &lines[i];
 103         }
 104
 105         tab->htab = htab;
 106         return(tab);
 107 }
 108
 109
 110 /*
 111  * Special character to Unicode codepoint.
 112  */
 113 int
 114 mchars_spec2cp(struct mchars *arg, const char *p, size_t sz)
 115 {
 116         const struct ln *ln;
 117
 118         ln = find(arg, p, sz, CHARS_CHAR);
 119         if (NULL == ln)
 120                 return(-1);
 121         return(ln->unicode);
 122 }
 123
 124
 125 /*
 126  * Reserved word to Unicode codepoint.
 127  */
 128 int
 129 mchars_res2cp(struct mchars *arg, const char *p, size_t sz)
 130 {
 131         const struct ln *ln;
 132
 133         ln = find(arg, p, sz, CHARS_STRING);
 134         if (NULL == ln)
 135                 return(-1);
 136         return(ln->unicode);
 137 }
 138
 139 /*
 140  * Numbered character to literal character.
 141  * This can only be a printable character (i.e., alnum, punct, space) so
 142  * prevent the character from ruining our state (backspace, newline, and
 143  * so on).
 144  */
 145 char
 146 mchars_num2char(const char *p, size_t sz)
 147 {
 148         int               i;
 149
 150         if (sz > 3)
 151                 return('\0');
 152
 153         i = atoi(p);
 154         /* LINTED */
 155         return(isprint(i) ? i : '\0');
 156 }
 157
 158 /*
 159  * Special character to string array.
 160  */
 161 const char *
 162 mchars_spec2str(struct mchars *arg, const char *p, size_t sz, size_t *rsz)
 163 {
 164         const struct ln *ln;
 165
 166         ln = find(arg, p, sz, CHARS_CHAR);
 167         if (NULL == ln)
 168                 return(NULL);
 169
 170         *rsz = strlen(ln->ascii);
 171         return(ln->ascii);
 172 }
 173
 174 /*
 175  * Reserved word to string array.
 176  */
 177 const char *
 178 mchars_res2str(struct mchars *arg, const char *p, size_t sz, size_t *rsz)
 179 {
 180         const struct ln *ln;
 181
 182         ln = find(arg, p, sz, CHARS_STRING);
 183         if (NULL == ln)
 184                 return(NULL);
 185
 186         *rsz = strlen(ln->ascii);
 187         return(ln->ascii);
 188 }
 189
 190 static const struct ln *
 191 find(struct mchars *tab, const char *p, size_t sz, int type)
 192 {
 193         struct ln        *pp, *prev;
 194         struct ln       **htab;
 195         int               hash;
 196
 197         assert(p);
 198         if (0 == sz)
 199                 return(NULL);
 200
 201         if (p[0] < PRINT_LO || p[0] > PRINT_HI)
 202                 return(NULL);
 203
 204         /*
 205          * Lookup the symbol in the symbol hash.  See ascii2htab for the
 206          * hashtable specs.  This dynamically re-orders the hash chain
 207          * to optimise for repeat hits.
 208          */
 209
 210         hash = (int)p[0] - PRINT_LO;
 211         htab = tab->htab;
 212
 213         if (NULL == (pp = htab[hash]))
 214                 return(NULL);
 215
 216         for (prev = NULL; pp; pp = pp->next) {
 217                 if ( ! match(pp, p, sz, type)) {
 218                         prev = pp;
 219                         continue;
 220                 }
 221
 222                 if (prev) {
 223                         prev->next = pp->next;
 224                         pp->next = htab[hash];
 225                         htab[hash] = pp;
 226                 }
 227
 228                 return(pp);
 229         }
 230
 231         return(NULL);
 232 }
 233
 234 static inline int
 235 match(const struct ln *ln, const char *p, size_t sz, int type)
 236 {
 237
 238         if ( ! (ln->type & type))
 239                 return(0);
 240         if (strncmp(ln->code, p, sz))
 241                 return(0);
 242         return('\0' == ln->code[(int)sz]);
 243 }