1 /*- 2 * Mach Operating System 3 * Copyright (c) 1991,1990 Carnegie Mellon University 4 * All Rights Reserved. 5 * 6 * Permission to use, copy, modify and distribute this software and its 7 * documentation is hereby granted, provided that both the copyright 8 * notice and this permission notice appear in all copies of the 9 * software, derivative works or modified versions, and any portions 10 * thereof, and that both notices appear in supporting documentation. 11 * 12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 15 * 16 * Carnegie Mellon requests users of this software to return to 17 * 18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 19 * School of Computer Science 20 * Carnegie Mellon University 21 * Pittsburgh PA 15213-3890 22 * 23 * any improvements or extensions that they make and grant Carnegie the 24 * rights to redistribute these changes. 25 */ 26 /* 27 * Author: David B. Golub, Carnegie Mellon University 28 * Date: 7/90 29 */ 30 /* 31 * Lexical analyzer. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include <sys/param.h> 38 #include <sys/libkern.h> 39 40 #include <ddb/ddb.h> 41 #include <ddb/db_lex.h> 42 43 static char db_line[DB_MAXLINE]; 44 static char * db_lp, *db_endlp; 45 46 static int db_lex(void); 47 static void db_flush_line(void); 48 static int db_read_char(void); 49 static void db_unread_char(int); 50 51 int 52 db_read_line() 53 { 54 int i; 55 56 i = db_readline(db_line, sizeof(db_line)); 57 if (i == 0) 58 return (0); /* EOI */ 59 db_lp = db_line; 60 db_endlp = db_lp + i; 61 return (i); 62 } 63 64 /* 65 * Simulate a line of input into DDB. 66 */ 67 void 68 db_inject_line(const char *command) 69 { 70 71 strlcpy(db_line, command, sizeof(db_line)); 72 db_lp = db_line; 73 db_endlp = db_lp + strlen(command); 74 } 75 76 /* 77 * In rare cases, we may want to pull the remainder of the line input 78 * verbatim, rather than lexing it. For example, when assigning literal 79 * values associated with scripts. In that case, return a static pointer to 80 * the current location in the input buffer. The caller must be aware that 81 * the contents are not stable if other lex/input calls are made. 82 */ 83 char * 84 db_get_line(void) 85 { 86 87 return (db_lp); 88 } 89 90 static void 91 db_flush_line() 92 { 93 db_lp = db_line; 94 db_endlp = db_line; 95 } 96 97 static int db_look_char = 0; 98 99 static int 100 db_read_char() 101 { 102 int c; 103 104 if (db_look_char != 0) { 105 c = db_look_char; 106 db_look_char = 0; 107 } 108 else if (db_lp >= db_endlp) 109 c = -1; 110 else 111 c = *db_lp++; 112 return (c); 113 } 114 115 static void 116 db_unread_char(c) 117 int c; 118 { 119 db_look_char = c; 120 } 121 122 static int db_look_token = 0; 123 124 void 125 db_unread_token(t) 126 int t; 127 { 128 db_look_token = t; 129 } 130 131 int 132 db_read_token() 133 { 134 int t; 135 136 if (db_look_token) { 137 t = db_look_token; 138 db_look_token = 0; 139 } 140 else 141 t = db_lex(); 142 return (t); 143 } 144 145 db_expr_t db_tok_number; 146 char db_tok_string[TOK_STRING_SIZE]; 147 148 db_expr_t db_radix = 16; 149 150 void 151 db_flush_lex() 152 { 153 db_flush_line(); 154 db_look_char = 0; 155 db_look_token = 0; 156 } 157 158 static int 159 db_lex() 160 { 161 int c; 162 163 c = db_read_char(); 164 while (c <= ' ' || c > '~') { 165 if (c == '\n' || c == -1) 166 return (tEOL); 167 c = db_read_char(); 168 } 169 170 if (c >= '0' && c <= '9') { 171 /* number */ 172 int r, digit = 0; 173 174 if (c > '0') 175 r = db_radix; 176 else { 177 c = db_read_char(); 178 if (c == 'O' || c == 'o') 179 r = 8; 180 else if (c == 'T' || c == 't') 181 r = 10; 182 else if (c == 'X' || c == 'x') 183 r = 16; 184 else { 185 r = db_radix; 186 db_unread_char(c); 187 } 188 c = db_read_char(); 189 } 190 db_tok_number = 0; 191 for (;;) { 192 if (c >= '0' && c <= ((r == 8) ? '7' : '9')) 193 digit = c - '0'; 194 else if (r == 16 && ((c >= 'A' && c <= 'F') || 195 (c >= 'a' && c <= 'f'))) { 196 if (c >= 'a') 197 digit = c - 'a' + 10; 198 else if (c >= 'A') 199 digit = c - 'A' + 10; 200 } 201 else 202 break; 203 db_tok_number = db_tok_number * r + digit; 204 c = db_read_char(); 205 } 206 if ((c >= '0' && c <= '9') || 207 (c >= 'A' && c <= 'Z') || 208 (c >= 'a' && c <= 'z') || 209 (c == '_')) 210 { 211 db_error("Bad character in number\n"); 212 db_flush_lex(); 213 return (tEOF); 214 } 215 db_unread_char(c); 216 return (tNUMBER); 217 } 218 if ((c >= 'A' && c <= 'Z') || 219 (c >= 'a' && c <= 'z') || 220 c == '_' || c == '\\') 221 { 222 /* string */ 223 char *cp; 224 225 cp = db_tok_string; 226 if (c == '\\') { 227 c = db_read_char(); 228 if (c == '\n' || c == -1) 229 db_error("Bad escape\n"); 230 } 231 *cp++ = c; 232 while (1) { 233 c = db_read_char(); 234 if ((c >= 'A' && c <= 'Z') || 235 (c >= 'a' && c <= 'z') || 236 (c >= '0' && c <= '9') || 237 c == '_' || c == '\\' || c == ':' || c == '.') 238 { 239 if (c == '\\') { 240 c = db_read_char(); 241 if (c == '\n' || c == -1) 242 db_error("Bad escape\n"); 243 } 244 *cp++ = c; 245 if (cp == db_tok_string+sizeof(db_tok_string)) { 246 db_error("String too long\n"); 247 db_flush_lex(); 248 return (tEOF); 249 } 250 continue; 251 } 252 else { 253 *cp = '\0'; 254 break; 255 } 256 } 257 db_unread_char(c); 258 return (tIDENT); 259 } 260 261 switch (c) { 262 case '+': 263 return (tPLUS); 264 case '-': 265 return (tMINUS); 266 case '.': 267 c = db_read_char(); 268 if (c == '.') 269 return (tDOTDOT); 270 db_unread_char(c); 271 return (tDOT); 272 case '*': 273 return (tSTAR); 274 case '/': 275 return (tSLASH); 276 case '=': 277 return (tEQ); 278 case '%': 279 return (tPCT); 280 case '#': 281 return (tHASH); 282 case '(': 283 return (tLPAREN); 284 case ')': 285 return (tRPAREN); 286 case ',': 287 return (tCOMMA); 288 case '"': 289 return (tDITTO); 290 case '$': 291 return (tDOLLAR); 292 case '!': 293 return (tEXCL); 294 case ';': 295 return (tSEMI); 296 case '<': 297 c = db_read_char(); 298 if (c == '<') 299 return (tSHIFT_L); 300 db_unread_char(c); 301 break; 302 case '>': 303 c = db_read_char(); 304 if (c == '>') 305 return (tSHIFT_R); 306 db_unread_char(c); 307 break; 308 case -1: 309 return (tEOF); 310 } 311 db_printf("Bad character\n"); 312 db_flush_lex(); 313 return (tEOF); 314 } 315