db_lex.c revision 1.24
1 /* $NetBSD: db_lex.c,v 1.24 2019/10/02 09:36:30 rin 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 (at) 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 1.24 2019/10/02 09:36:30 rin Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/cpu.h> 42 43 #include <ddb/ddb.h> 44 45 db_expr_t db_tok_number; 46 char db_tok_string[TOK_STRING_SIZE]; 47 48 static char db_line[DB_LINE_MAXLEN]; 49 static const char *db_lp; 50 static const char *db_endlp; 51 52 static int db_look_char = 0; 53 static int db_look_token = 0; 54 55 static void db_flush_line(void); 56 static int db_read_char(void); 57 static void db_unread_char(int); 58 static int db_lex(void); 59 60 int 61 db_read_line(void) 62 { 63 int i; 64 65 #ifdef MULTIPROCESSOR 66 db_printf("db{%ld}> ", (long)cpu_number()); 67 #else 68 db_printf("db> "); 69 #endif 70 i = db_readline(db_line, sizeof(db_line)); 71 if (i == 0) 72 return (0); /* EOI */ 73 db_set_line(db_line, db_line + i); 74 return (i); 75 } 76 77 void 78 db_set_line(const char *sp, const char *ep) 79 { 80 81 db_lp = sp; 82 db_endlp = ep; 83 } 84 85 static void 86 db_flush_line(void) 87 { 88 89 db_lp = db_line; 90 db_endlp = db_line; 91 } 92 93 static int 94 db_read_char(void) 95 { 96 int c; 97 98 if (db_look_char != 0) { 99 c = db_look_char; 100 db_look_char = 0; 101 } 102 else if (db_lp >= db_endlp) 103 c = -1; 104 else 105 c = *db_lp++; 106 return (c); 107 } 108 109 static void 110 db_unread_char(int c) 111 { 112 113 db_look_char = c; 114 } 115 116 void 117 db_unread_token(int t) 118 { 119 120 db_look_token = t; 121 } 122 123 int 124 db_read_token(void) 125 { 126 int t; 127 128 if (db_look_token) { 129 t = db_look_token; 130 db_look_token = 0; 131 } 132 else 133 t = db_lex(); 134 return (t); 135 } 136 137 int db_radix = 16; 138 139 /* 140 * Convert the number to a string in the current radix. 141 * This replaces the non-standard %n printf() format. 142 */ 143 144 char * 145 db_num_to_str(db_expr_t val) 146 { 147 148 /* 149 * 2 chars for "0x", 1 for a sign ("-") 150 * up to 21 chars for a 64-bit number: 151 * % echo 2^64 | bc | wc -c 152 * 21 153 * and 1 char for a terminal NUL 154 * 2+1+21+1 => 25 155 */ 156 static char buf[25]; 157 158 if (db_radix == 16) 159 snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "x", val); 160 else if (db_radix == 8) 161 snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "o", val); 162 else 163 snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "u", val); 164 165 return (buf); 166 } 167 168 void 169 db_flush_lex(void) 170 { 171 172 db_flush_line(); 173 db_look_char = 0; 174 db_look_token = 0; 175 } 176 177 static int 178 db_lex(void) 179 { 180 int c; 181 182 c = db_read_char(); 183 while (c <= ' ' || c > '~') { 184 if (c == '\n' || c == -1) 185 return (tEOL); 186 c = db_read_char(); 187 } 188 189 if (c >= '0' && c <= '9') { 190 /* number */ 191 db_expr_t r, digit = 0; 192 193 if (c > '0') 194 r = db_radix; 195 else { 196 c = db_read_char(); 197 if (c == 'O' || c == 'o') 198 r = 8; 199 else if (c == 'T' || c == 't') 200 r = 10; 201 else if (c == 'X' || c == 'x') 202 r = 16; 203 else { 204 r = db_radix; 205 db_unread_char(c); 206 } 207 c = db_read_char(); 208 } 209 db_tok_number = 0; 210 for (;;) { 211 if (c >= '0' && c <= ((r == 8) ? '7' : '9')) 212 digit = c - '0'; 213 else if (r == 16) { 214 if (c >= 'A' && c <= 'F') 215 digit = c - 'A' + 10; 216 else if (c >= 'a' && c <= 'f') 217 digit = c - 'a' + 10; 218 else 219 break; 220 } else 221 break; 222 db_tok_number = db_tok_number * r + digit; 223 c = db_read_char(); 224 } 225 if ((c >= '0' && c <= '9') || 226 (c >= 'A' && c <= 'Z') || 227 (c >= 'a' && c <= 'z') || 228 (c == '_')) { 229 db_error("Bad character in number\n"); 230 /*NOTREACHED*/ 231 } 232 db_unread_char(c); 233 return (tNUMBER); 234 } 235 if ((c >= 'A' && c <= 'Z') || 236 (c >= 'a' && c <= 'z') || 237 c == '_' || c == '\\') { 238 /* string */ 239 char *cp; 240 241 cp = db_tok_string; 242 if (c == '\\') { 243 c = db_read_char(); 244 if (c == '\n' || c == -1) { 245 db_error("Bad escape\n"); 246 /*NOTREACHED*/ 247 } 248 } 249 *cp++ = c; 250 while (1) { 251 c = db_read_char(); 252 if ((c >= 'A' && c <= 'Z') || 253 (c >= 'a' && c <= 'z') || 254 (c >= '0' && c <= '9') || 255 c == '_' || c == '\\' || c == ':') { 256 if (c == '\\') { 257 c = db_read_char(); 258 if (c == '\n' || c == -1) { 259 db_error("Bad escape\n"); 260 /*NOTREACHED*/ 261 } 262 } 263 *cp++ = c; 264 if (cp == db_tok_string+sizeof(db_tok_string)) { 265 db_error("String too long\n"); 266 /*NOTREACHED*/ 267 } 268 continue; 269 } else { 270 *cp = '\0'; 271 break; 272 } 273 } 274 db_unread_char(c); 275 return (tIDENT); 276 } 277 278 switch (c) { 279 case '+': 280 return (tPLUS); 281 case '-': 282 return (tMINUS); 283 case '.': 284 c = db_read_char(); 285 if (c == '.') 286 return (tDOTDOT); 287 db_unread_char(c); 288 return (tDOT); 289 case '*': 290 return (tSTAR); 291 case '/': 292 return (tSLASH); 293 case '=': 294 return (tEQ); 295 case '%': 296 return (tPCT); 297 case '#': 298 return (tHASH); 299 case '(': 300 return (tLPAREN); 301 case ')': 302 return (tRPAREN); 303 case ',': 304 return (tCOMMA); 305 case '"': 306 return (tDITTO); 307 case '$': 308 return (tDOLLAR); 309 case '!': 310 return (tEXCL); 311 case '<': 312 c = db_read_char(); 313 if (c == '<') 314 return (tSHIFT_L); 315 db_unread_char(c); 316 break; 317 case '>': 318 c = db_read_char(); 319 if (c == '>') 320 return (tSHIFT_R); 321 db_unread_char(c); 322 break; 323 case -1: 324 return (tEOF); 325 } 326 db_printf("Bad character\n"); 327 db_flush_lex(); 328 return (tEOF); 329 } 330 331 /* 332 * Utility routine - discard tokens through end-of-line. 333 */ 334 void 335 db_skip_to_eol(void) 336 { 337 int t; 338 339 do { 340 t = db_read_token(); 341 } while (t != tEOL); 342 } 343 344 void 345 db_error(const char *s) 346 { 347 348 if (s) 349 db_printf("%s", s); 350 db_flush_lex(); 351 longjmp(db_recover); 352 } 353
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