1 /* ccl - routines for character classes */ 2 3 /* Copyright (c) 1990 The Regents of the University of California. */ 4 /* All rights reserved. */ 5 6 /* This code is derived from software contributed to Berkeley by */ 7 /* Vern Paxson. */ 8 9 /* The United States Government has rights in this work pursuant */ 10 /* to contract no. DE-AC03-76SF00098 between the United States */ 11 /* Department of Energy and the University of California. */ 12 13 /* This file is part of flex. */ 14 15 /* Redistribution and use in source and binary forms, with or without */ 16 /* modification, are permitted provided that the following conditions */ 17 /* are met: */ 18 19 /* 1. Redistributions of source code must retain the above copyright */ 20 /* notice, this list of conditions and the following disclaimer. */ 21 /* 2. Redistributions in binary form must reproduce the above copyright */ 22 /* notice, this list of conditions and the following disclaimer in the */ 23 /* documentation and/or other materials provided with the distribution. */ 24 25 /* Neither the name of the University nor the names of its contributors */ 26 /* may be used to endorse or promote products derived from this software */ 27 /* without specific prior written permission. */ 28 29 /* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */ 30 /* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */ 31 /* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */ 32 /* PURPOSE. */ 33 #include "flexdef.h" 34 __RCSID("$NetBSD: ccl.c,v 1.3 2017/01/02 17:45:27 christos Exp $"); 35 36 37 /* return true if the chr is in the ccl. Takes negation into account. */ 38 static bool 39 ccl_contains (const int cclp, const int ch) 40 { 41 int ind, len, i; 42 43 len = ccllen[cclp]; 44 ind = cclmap[cclp]; 45 46 for (i = 0; i < len; ++i) 47 if (ccltbl[ind + i] == ch) 48 return !cclng[cclp]; 49 50 return cclng[cclp]; 51 } 52 53 54 /* ccladd - add a single character to a ccl */ 55 56 void ccladd (int cclp, int ch) 57 { 58 int ind, len, newpos, i; 59 60 check_char (ch); 61 62 len = ccllen[cclp]; 63 ind = cclmap[cclp]; 64 65 /* check to see if the character is already in the ccl */ 66 67 for (i = 0; i < len; ++i) 68 if (ccltbl[ind + i] == ch) 69 return; 70 71 /* mark newlines */ 72 if (ch == nlch) 73 ccl_has_nl[cclp] = true; 74 75 newpos = ind + len; 76 77 if (newpos >= current_max_ccl_tbl_size) { 78 current_max_ccl_tbl_size += MAX_CCL_TBL_SIZE_INCREMENT; 79 80 ++num_reallocs; 81 82 ccltbl = reallocate_Character_array (ccltbl, 83 current_max_ccl_tbl_size); 84 } 85 86 ccllen[cclp] = len + 1; 87 ccltbl[newpos] = (unsigned char) ch; 88 } 89 90 /* dump_cclp - same thing as list_character_set, but for cclps. */ 91 92 static void dump_cclp (FILE* file, int cclp) 93 { 94 int i; 95 96 putc ('[', file); 97 98 for (i = 0; i < csize; ++i) { 99 if (ccl_contains(cclp, i)){ 100 int start_char = i; 101 102 putc (' ', file); 103 104 fputs (readable_form (i), file); 105 106 while (++i < csize && ccl_contains(cclp,i)) ; 107 108 if (i - 1 > start_char) 109 /* this was a run */ 110 fprintf (file, "-%s", 111 readable_form (i - 1)); 112 113 putc (' ', file); 114 } 115 } 116 117 putc (']', file); 118 } 119 120 121 122 /* ccl_set_diff - create a new ccl as the set difference of the two given ccls. */ 123 int 124 ccl_set_diff (int a, int b) 125 { 126 int d, ch; 127 128 /* create new class */ 129 d = cclinit(); 130 131 /* In order to handle negation, we spin through all possible chars, 132 * addding each char in a that is not in b. 133 * (This could be O(n^2), but n is small and bounded.) 134 */ 135 for ( ch = 0; ch < csize; ++ch ) 136 if (ccl_contains (a, ch) && !ccl_contains(b, ch)) 137 ccladd (d, ch); 138 139 /* debug */ 140 if (0){ 141 fprintf(stderr, "ccl_set_diff ("); 142 fprintf(stderr, "\n "); 143 dump_cclp (stderr, a); 144 fprintf(stderr, "\n "); 145 dump_cclp (stderr, b); 146 fprintf(stderr, "\n "); 147 dump_cclp (stderr, d); 148 fprintf(stderr, "\n)\n"); 149 } 150 return d; 151 } 152 153 /* ccl_set_union - create a new ccl as the set union of the two given ccls. */ 154 int 155 ccl_set_union (int a, int b) 156 { 157 int d, i; 158 159 /* create new class */ 160 d = cclinit(); 161 162 /* Add all of a */ 163 for (i = 0; i < ccllen[a]; ++i) 164 ccladd (d, ccltbl[cclmap[a] + i]); 165 166 /* Add all of b */ 167 for (i = 0; i < ccllen[b]; ++i) 168 ccladd (d, ccltbl[cclmap[b] + i]); 169 170 /* debug */ 171 if (0){ 172 fprintf(stderr, "ccl_set_union (%d + %d = %d", a, b, d); 173 fprintf(stderr, "\n "); 174 dump_cclp (stderr, a); 175 fprintf(stderr, "\n "); 176 dump_cclp (stderr, b); 177 fprintf(stderr, "\n "); 178 dump_cclp (stderr, d); 179 fprintf(stderr, "\n)\n"); 180 } 181 return d; 182 } 183 184 185 /* cclinit - return an empty ccl */ 186 187 int cclinit (void) 188 { 189 if (++lastccl >= current_maxccls) { 190 current_maxccls += MAX_CCLS_INCREMENT; 191 192 ++num_reallocs; 193 194 cclmap = 195 reallocate_integer_array (cclmap, current_maxccls); 196 ccllen = 197 reallocate_integer_array (ccllen, current_maxccls); 198 cclng = reallocate_integer_array (cclng, current_maxccls); 199 ccl_has_nl = 200 reallocate_bool_array (ccl_has_nl, 201 current_maxccls); 202 } 203 204 if (lastccl == 1) 205 /* we're making the first ccl */ 206 cclmap[lastccl] = 0; 207 208 else 209 /* The new pointer is just past the end of the last ccl. 210 * Since the cclmap points to the \first/ character of a 211 * ccl, adding the length of the ccl to the cclmap pointer 212 * will produce a cursor to the first free space. 213 */ 214 cclmap[lastccl] = 215 cclmap[lastccl - 1] + ccllen[lastccl - 1]; 216 217 ccllen[lastccl] = 0; 218 cclng[lastccl] = 0; /* ccl's start out life un-negated */ 219 ccl_has_nl[lastccl] = false; 220 221 return lastccl; 222 } 223 224 225 /* cclnegate - negate the given ccl */ 226 227 void cclnegate (int cclp) 228 { 229 cclng[cclp] = 1; 230 ccl_has_nl[cclp] = !ccl_has_nl[cclp]; 231 } 232 233 234 /* list_character_set - list the members of a set of characters in CCL form 235 * 236 * Writes to the given file a character-class representation of those 237 * characters present in the given CCL. A character is present if it 238 * has a non-zero value in the cset array. 239 */ 240 241 void list_character_set (FILE *file, int cset[]) 242 { 243 int i; 244 245 putc ('[', file); 246 247 for (i = 0; i < csize; ++i) { 248 if (cset[i]) { 249 int start_char = i; 250 251 putc (' ', file); 252 253 fputs (readable_form (i), file); 254 255 while (++i < csize && cset[i]) ; 256 257 if (i - 1 > start_char) 258 /* this was a run */ 259 fprintf (file, "-%s", 260 readable_form (i - 1)); 261 262 putc (' ', file); 263 } 264 } 265 266 putc (']', file); 267 } 268 269 /** Determines if the range [c1-c2] is unambiguous in a case-insensitive 270 * scanner. Specifically, if a lowercase or uppercase character, x, is in the 271 * range [c1-c2], then we require that UPPERCASE(x) and LOWERCASE(x) must also 272 * be in the range. If not, then this range is ambiguous, and the function 273 * returns false. For example, [@-_] spans [a-z] but not [A-Z]. Beware that 274 * [a-z] will be labeled ambiguous because it does not include [A-Z]. 275 * 276 * @param c1 the lower end of the range 277 * @param c2 the upper end of the range 278 * @return true if [c1-c2] is not ambiguous for a caseless scanner. 279 */ 280 bool range_covers_case (int c1, int c2) 281 { 282 int i, o; 283 284 for (i = c1; i <= c2; i++) { 285 if (has_case (i)) { 286 o = reverse_case (i); 287 if (o < c1 || c2 < o) 288 return false; 289 } 290 } 291 return true; 292 } 293 294 /** Reverse the case of a character, if possible. 295 * @return c if case-reversal does not apply. 296 */ 297 int reverse_case (int c) 298 { 299 return isupper (c) ? tolower (c) : (islower (c) ? toupper (c) : c); 300 } 301 302 /** Return true if c is uppercase or lowercase. */ 303 bool has_case (int c) 304 { 305 return (isupper (c) || islower (c)) ? true : false; 306 } 307