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 * $FreeBSD: src/sys/ddb/db_lex.c,v 1.18 1999/08/28 00:41:08 peter Exp $ 27 * $DragonFly: src/sys/ddb/db_lex.c,v 1.3 2003/08/27 10:47:13 rob Exp $ 28 */ 29 30 /* 31 * Author: David B. Golub, Carnegie Mellon University 32 * Date: 7/90 33 */ 34 /* 35 * Lexical analyzer. 36 */ 37 #include <sys/param.h> 38 39 #include <ddb/ddb.h> 40 #include <ddb/db_lex.h> 41 42 static char db_line[120]; 43 static char * db_lp, *db_endlp; 44 45 static int db_lex (void); 46 static void db_flush_line (void); 47 static int db_read_char (void); 48 static void db_unread_char (int); 49 50 int 51 db_read_line() 52 { 53 int i; 54 55 i = db_readline(db_line, sizeof(db_line)); 56 if (i == 0) 57 return (0); /* EOI */ 58 db_lp = db_line; 59 db_endlp = db_lp + i; 60 return (i); 61 } 62 63 static void 64 db_flush_line() 65 { 66 db_lp = db_line; 67 db_endlp = db_line; 68 } 69 70 static int db_look_char = 0; 71 72 static int 73 db_read_char() 74 { 75 int c; 76 77 if (db_look_char != 0) { 78 c = db_look_char; 79 db_look_char = 0; 80 } 81 else if (db_lp >= db_endlp) 82 c = -1; 83 else 84 c = *db_lp++; 85 return (c); 86 } 87 88 static void 89 db_unread_char(c) 90 int c; 91 { 92 db_look_char = c; 93 } 94 95 static int db_look_token = 0; 96 97 void 98 db_unread_token(t) 99 int t; 100 { 101 db_look_token = t; 102 } 103 104 int 105 db_read_token() 106 { 107 int t; 108 109 if (db_look_token) { 110 t = db_look_token; 111 db_look_token = 0; 112 } 113 else 114 t = db_lex(); 115 return (t); 116 } 117 118 db_expr_t db_tok_number; 119 char db_tok_string[TOK_STRING_SIZE]; 120 121 db_expr_t db_radix = 16; 122 123 void 124 db_flush_lex() 125 { 126 db_flush_line(); 127 db_look_char = 0; 128 db_look_token = 0; 129 } 130 131 static int 132 db_lex() 133 { 134 int c; 135 136 c = db_read_char(); 137 while (c <= ' ' || c > '~') { 138 if (c == '\n' || c == -1) 139 return (tEOL); 140 c = db_read_char(); 141 } 142 143 if (c >= '0' && c <= '9') { 144 /* number */ 145 int r, digit = 0; 146 147 if (c > '0') 148 r = db_radix; 149 else { 150 c = db_read_char(); 151 if (c == 'O' || c == 'o') 152 r = 8; 153 else if (c == 'T' || c == 't') 154 r = 10; 155 else if (c == 'X' || c == 'x') 156 r = 16; 157 else { 158 r = db_radix; 159 db_unread_char(c); 160 } 161 c = db_read_char(); 162 } 163 db_tok_number = 0; 164 for (;;) { 165 if (c >= '0' && c <= ((r == 8) ? '7' : '9')) 166 digit = c - '0'; 167 else if (r == 16 && ((c >= 'A' && c <= 'F') || 168 (c >= 'a' && c <= 'f'))) { 169 if (c >= 'a') 170 digit = c - 'a' + 10; 171 else if (c >= 'A') 172 digit = c - 'A' + 10; 173 } 174 else 175 break; 176 db_tok_number = db_tok_number * r + digit; 177 c = db_read_char(); 178 } 179 if ((c >= '0' && c <= '9') || 180 (c >= 'A' && c <= 'Z') || 181 (c >= 'a' && c <= 'z') || 182 (c == '_')) 183 { 184 db_error("Bad character in number\n"); 185 db_flush_lex(); 186 return (tEOF); 187 } 188 db_unread_char(c); 189 return (tNUMBER); 190 } 191 if ((c >= 'A' && c <= 'Z') || 192 (c >= 'a' && c <= 'z') || 193 c == '_' || c == '\\') 194 { 195 /* string */ 196 char *cp; 197 198 cp = db_tok_string; 199 if (c == '\\') { 200 c = db_read_char(); 201 if (c == '\n' || c == -1) 202 db_error("Bad escape\n"); 203 } 204 *cp++ = c; 205 while (1) { 206 c = db_read_char(); 207 if ((c >= 'A' && c <= 'Z') || 208 (c >= 'a' && c <= 'z') || 209 (c >= '0' && c <= '9') || 210 c == '_' || c == '\\' || c == ':') 211 { 212 if (c == '\\') { 213 c = db_read_char(); 214 if (c == '\n' || c == -1) 215 db_error("Bad escape\n"); 216 } 217 *cp++ = c; 218 if (cp == db_tok_string+sizeof(db_tok_string)) { 219 db_error("String too long\n"); 220 db_flush_lex(); 221 return (tEOF); 222 } 223 continue; 224 } 225 else { 226 *cp = '\0'; 227 break; 228 } 229 } 230 db_unread_char(c); 231 return (tIDENT); 232 } 233 234 switch (c) { 235 case '+': 236 return (tPLUS); 237 case '-': 238 return (tMINUS); 239 case '.': 240 c = db_read_char(); 241 if (c == '.') 242 return (tDOTDOT); 243 db_unread_char(c); 244 return (tDOT); 245 case '*': 246 return (tSTAR); 247 case '/': 248 return (tSLASH); 249 case '=': 250 return (tEQ); 251 case '%': 252 return (tPCT); 253 case '#': 254 return (tHASH); 255 case '(': 256 return (tLPAREN); 257 case ')': 258 return (tRPAREN); 259 case ',': 260 return (tCOMMA); 261 case '"': 262 return (tDITTO); 263 case '$': 264 return (tDOLLAR); 265 case '!': 266 return (tEXCL); 267 case '<': 268 c = db_read_char(); 269 if (c == '<') 270 return (tSHIFT_L); 271 db_unread_char(c); 272 break; 273 case '>': 274 c = db_read_char(); 275 if (c == '>') 276 return (tSHIFT_R); 277 db_unread_char(c); 278 break; 279 case -1: 280 return (tEOF); 281 } 282 db_printf("Bad character\n"); 283 db_flush_lex(); 284 return (tEOF); 285 } 286