1 /* $NetBSD: db_expr.c,v 1.12 2001/11/12 22:54:05 lukem 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 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: db_expr.c,v 1.12 2001/11/12 22:54:05 lukem Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/proc.h> 37 38 #include <machine/db_machdep.h> 39 40 #include <ddb/db_lex.h> 41 #include <ddb/db_access.h> 42 #include <ddb/db_command.h> 43 #include <ddb/db_sym.h> 44 #include <ddb/db_extern.h> 45 #include <ddb/db_variables.h> 46 47 boolean_t 48 db_term(valuep) 49 db_expr_t *valuep; 50 { 51 int t; 52 53 t = db_read_token(); 54 if (t == tIDENT) { 55 if (!db_value_of_name(db_tok_string, valuep)) { 56 extern int db_radix; 57 db_expr_t v = 0; 58 int i, c, byte; 59 60 /* See if we can make a number out of all of it */ 61 for (i = 0; (c = db_tok_string[i]) != '\0'; i++) { 62 byte = 0; 63 if (c >= '0' && c <= '9') 64 byte = c - '0'; 65 else if (db_radix == 16 && c >= 'a' && c <= 'f') 66 byte = c - 'a' + 10; 67 else if (db_radix == 16 && c >= 'A' && c <= 'F') 68 byte = c - 'A' + 10; 69 else 70 db_error("Symbol not found\n"); 71 /*NOTREACHED*/ 72 v = v * db_radix + byte; 73 } 74 *valuep = (db_expr_t)v; 75 } 76 return (TRUE); 77 } 78 if (t == tNUMBER) { 79 *valuep = (db_expr_t)db_tok_number; 80 return (TRUE); 81 } 82 if (t == tDOT) { 83 *valuep = (db_expr_t)db_dot; 84 return (TRUE); 85 } 86 if (t == tDOTDOT) { 87 *valuep = (db_expr_t)db_prev; 88 return (TRUE); 89 } 90 if (t == tPLUS) { 91 *valuep = (db_expr_t) db_next; 92 return (TRUE); 93 } 94 if (t == tDITTO) { 95 *valuep = (db_expr_t)db_last_addr; 96 return (TRUE); 97 } 98 if (t == tDOLLAR) { 99 if (!db_get_variable(valuep)) 100 return (FALSE); 101 return (TRUE); 102 } 103 if (t == tLPAREN) { 104 if (!db_expression(valuep)) { 105 db_error("Syntax error\n"); 106 /*NOTREACHED*/ 107 } 108 t = db_read_token(); 109 if (t != tRPAREN) { 110 db_error("Syntax error\n"); 111 /*NOTREACHED*/ 112 } 113 return (TRUE); 114 } 115 db_unread_token(t); 116 return (FALSE); 117 } 118 119 boolean_t 120 db_unary(valuep) 121 db_expr_t *valuep; 122 { 123 int t; 124 125 t = db_read_token(); 126 if (t == tMINUS) { 127 if (!db_unary(valuep)) { 128 db_error("Syntax error\n"); 129 /*NOTREACHED*/ 130 } 131 *valuep = -*valuep; 132 return (TRUE); 133 } 134 if (t == tSTAR) { 135 /* indirection */ 136 if (!db_unary(valuep)) { 137 db_error("Syntax error\n"); 138 /*NOTREACHED*/ 139 } 140 *valuep = db_get_value((db_addr_t)*valuep, sizeof(db_expr_t), 141 FALSE); 142 return (TRUE); 143 } 144 db_unread_token(t); 145 return (db_term(valuep)); 146 } 147 148 boolean_t 149 db_mult_expr(valuep) 150 db_expr_t *valuep; 151 { 152 db_expr_t lhs, rhs; 153 int t; 154 155 if (!db_unary(&lhs)) 156 return (FALSE); 157 158 t = db_read_token(); 159 while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH) { 160 if (!db_term(&rhs)) { 161 db_error("Syntax error\n"); 162 /*NOTREACHED*/ 163 } 164 if (t == tSTAR) 165 lhs *= rhs; 166 else { 167 if (rhs == 0) { 168 db_error("Divide by 0\n"); 169 /*NOTREACHED*/ 170 } 171 if (t == tSLASH) 172 lhs /= rhs; 173 else if (t == tPCT) 174 lhs %= rhs; 175 else 176 lhs = ((lhs+rhs-1)/rhs)*rhs; 177 } 178 t = db_read_token(); 179 } 180 db_unread_token(t); 181 *valuep = lhs; 182 return (TRUE); 183 } 184 185 boolean_t 186 db_add_expr(valuep) 187 db_expr_t *valuep; 188 { 189 db_expr_t lhs, rhs; 190 int t; 191 192 if (!db_mult_expr(&lhs)) 193 return (FALSE); 194 195 t = db_read_token(); 196 while (t == tPLUS || t == tMINUS) { 197 if (!db_mult_expr(&rhs)) { 198 db_error("Syntax error\n"); 199 /*NOTREACHED*/ 200 } 201 if (t == tPLUS) 202 lhs += rhs; 203 else 204 lhs -= rhs; 205 t = db_read_token(); 206 } 207 db_unread_token(t); 208 *valuep = lhs; 209 return (TRUE); 210 } 211 212 boolean_t 213 db_shift_expr(valuep) 214 db_expr_t *valuep; 215 { 216 db_expr_t lhs, rhs; 217 int t; 218 219 if (!db_add_expr(&lhs)) 220 return (FALSE); 221 222 t = db_read_token(); 223 while (t == tSHIFT_L || t == tSHIFT_R) { 224 if (!db_add_expr(&rhs)) { 225 db_error("Syntax error\n"); 226 /*NOTREACHED*/ 227 } 228 if (rhs < 0) { 229 db_error("Negative shift amount\n"); 230 /*NOTREACHED*/ 231 } 232 if (t == tSHIFT_L) 233 lhs <<= rhs; 234 else { 235 /* Shift right is unsigned */ 236 lhs = (unsigned long) lhs >> rhs; 237 } 238 t = db_read_token(); 239 } 240 db_unread_token(t); 241 *valuep = lhs; 242 return (TRUE); 243 } 244 245 int 246 db_expression(valuep) 247 db_expr_t *valuep; 248 { 249 return (db_shift_expr(valuep)); 250 } 251