1 /* $NetBSD: db_lex.c,v 1.22 2011/05/26 15:34:14 joerg Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: David B. Golub, Carnegie Mellon University 29 * Date: 7/90 30 */ 31 32 /* 33 * Lexical analyzer. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: db_lex.c,v 1.22 2011/05/26 15:34:14 joerg Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 42 #include <ddb/ddb.h> 43 44 db_expr_t db_tok_number; 45 char db_tok_string[TOK_STRING_SIZE]; 46 47 static char db_line[DB_LINE_MAXLEN]; 48 static const char *db_lp; 49 static const char *db_endlp; 50 51 static int db_look_char = 0; 52 static int db_look_token = 0; 53 54 static void db_flush_line(void); 55 static int db_read_char(void); 56 static void db_unread_char(int); 57 static int db_lex(void); 58 59 int 60 db_read_line(void) 61 { 62 int i; 63 64 i = db_readline(db_line, sizeof(db_line)); 65 if (i == 0) 66 return (0); /* EOI */ 67 db_set_line(db_line, db_line + i); 68 return (i); 69 } 70 71 void 72 db_set_line(const char *sp, const char *ep) 73 { 74 75 db_lp = sp; 76 db_endlp = ep; 77 } 78 79 static void 80 db_flush_line(void) 81 { 82 83 db_lp = db_line; 84 db_endlp = db_line; 85 } 86 87 static int 88 db_read_char(void) 89 { 90 int c; 91 92 if (db_look_char != 0) { 93 c = db_look_char; 94 db_look_char = 0; 95 } 96 else if (db_lp >= db_endlp) 97 c = -1; 98 else 99 c = *db_lp++; 100 return (c); 101 } 102 103 static void 104 db_unread_char(int c) 105 { 106 107 db_look_char = c; 108 } 109 110 void 111 db_unread_token(int t) 112 { 113 114 db_look_token = t; 115 } 116 117 int 118 db_read_token(void) 119 { 120 int t; 121 122 if (db_look_token) { 123 t = db_look_token; 124 db_look_token = 0; 125 } 126 else 127 t = db_lex(); 128 return (t); 129 } 130 131 int db_radix = 16; 132 133 /* 134 * Convert the number to a string in the current radix. 135 * This replaces the non-standard %n printf() format. 136 */ 137 138 char * 139 db_num_to_str(db_expr_t val) 140 { 141 142 /* 143 * 2 chars for "0x", 1 for a sign ("-") 144 * up to 21 chars for a 64-bit number: 145 * % echo 2^64 | bc | wc -c 146 * 21 147 * and 1 char for a terminal NUL 148 * 2+1+21+1 => 25 149 */ 150 static char buf[25]; 151 152 if (db_radix == 16) 153 snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "x", val); 154 else if (db_radix == 8) 155 snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "o", val); 156 else 157 snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "u", val); 158 159 return (buf); 160 } 161 162 void 163 db_flush_lex(void) 164 { 165 166 db_flush_line(); 167 db_look_char = 0; 168 db_look_token = 0; 169 } 170 171 static int 172 db_lex(void) 173 { 174 int c; 175 176 c = db_read_char(); 177 while (c <= ' ' || c > '~') { 178 if (c == '\n' || c == -1) 179 return (tEOL); 180 c = db_read_char(); 181 } 182 183 if (c >= '0' && c <= '9') { 184 /* number */ 185 db_expr_t r, digit = 0; 186 187 if (c > '0') 188 r = db_radix; 189 else { 190 c = db_read_char(); 191 if (c == 'O' || c == 'o') 192 r = 8; 193 else if (c == 'T' || c == 't') 194 r = 10; 195 else if (c == 'X' || c == 'x') 196 r = 16; 197 else { 198 r = db_radix; 199 db_unread_char(c); 200 } 201 c = db_read_char(); 202 } 203 db_tok_number = 0; 204 for (;;) { 205 if (c >= '0' && c <= ((r == 8) ? '7' : '9')) 206 digit = c - '0'; 207 else if (r == 16 && ((c >= 'A' && c <= 'F') || 208 (c >= 'a' && c <= 'f'))) { 209 if (c >= 'a') 210 digit = c - 'a' + 10; 211 else if (c >= 'A') 212 digit = c - 'A' + 10; 213 } 214 else 215 break; 216 db_tok_number = db_tok_number * r + digit; 217 c = db_read_char(); 218 } 219 if ((c >= '0' && c <= '9') || 220 (c >= 'A' && c <= 'Z') || 221 (c >= 'a' && c <= 'z') || 222 (c == '_')) { 223 db_error("Bad character in number\n"); 224 /*NOTREACHED*/ 225 } 226 db_unread_char(c); 227 return (tNUMBER); 228 } 229 if ((c >= 'A' && c <= 'Z') || 230 (c >= 'a' && c <= 'z') || 231 c == '_' || c == '\\') { 232 /* string */ 233 char *cp; 234 235 cp = db_tok_string; 236 if (c == '\\') { 237 c = db_read_char(); 238 if (c == '\n' || c == -1) { 239 db_error("Bad escape\n"); 240 /*NOTREACHED*/ 241 } 242 } 243 *cp++ = c; 244 while (1) { 245 c = db_read_char(); 246 if ((c >= 'A' && c <= 'Z') || 247 (c >= 'a' && c <= 'z') || 248 (c >= '0' && c <= '9') || 249 c == '_' || c == '\\' || c == ':') { 250 if (c == '\\') { 251 c = db_read_char(); 252 if (c == '\n' || c == -1) { 253 db_error("Bad escape\n"); 254 /*NOTREACHED*/ 255 } 256 } 257 *cp++ = c; 258 if (cp == db_tok_string+sizeof(db_tok_string)) { 259 db_error("String too long\n"); 260 /*NOTREACHED*/ 261 } 262 continue; 263 } else { 264 *cp = '\0'; 265 break; 266 } 267 } 268 db_unread_char(c); 269 return (tIDENT); 270 } 271 272 switch (c) { 273 case '+': 274 return (tPLUS); 275 case '-': 276 return (tMINUS); 277 case '.': 278 c = db_read_char(); 279 if (c == '.') 280 return (tDOTDOT); 281 db_unread_char(c); 282 return (tDOT); 283 case '*': 284 return (tSTAR); 285 case '/': 286 return (tSLASH); 287 case '=': 288 return (tEQ); 289 case '%': 290 return (tPCT); 291 case '#': 292 return (tHASH); 293 case '(': 294 return (tLPAREN); 295 case ')': 296 return (tRPAREN); 297 case ',': 298 return (tCOMMA); 299 case '"': 300 return (tDITTO); 301 case '$': 302 return (tDOLLAR); 303 case '!': 304 return (tEXCL); 305 case '<': 306 c = db_read_char(); 307 if (c == '<') 308 return (tSHIFT_L); 309 db_unread_char(c); 310 break; 311 case '>': 312 c = db_read_char(); 313 if (c == '>') 314 return (tSHIFT_R); 315 db_unread_char(c); 316 break; 317 case -1: 318 return (tEOF); 319 } 320 db_printf("Bad character\n"); 321 db_flush_lex(); 322 return (tEOF); 323 } 324 325 /* 326 * Utility routine - discard tokens through end-of-line. 327 */ 328 void 329 db_skip_to_eol(void) 330 { 331 int t; 332 333 do { 334 t = db_read_token(); 335 } while (t != tEOL); 336 } 337 338 void 339 db_error(const char *s) 340 { 341 342 if (s) 343 db_printf("%s", s); 344 db_flush_lex(); 345 longjmp(db_recover); 346 } 347