2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
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.
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.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
27 * Author: David B. Golub, Carnegie Mellon University
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
37 #include <ddb/db_lex.h>
38 #include <ddb/db_access.h>
39 #include <ddb/db_command.h>
41 static boolean_t db_add_expr(db_expr_t *valuep);
42 static boolean_t db_mult_expr(db_expr_t *valuep);
43 static boolean_t db_shift_expr(db_expr_t *valuep);
44 static boolean_t db_term(db_expr_t *valuep);
45 static boolean_t db_unary(db_expr_t *valuep);
48 db_term(db_expr_t *valuep)
54 if (!db_value_of_name(db_tok_string, valuep) &&
55 !db_value_of_name_pcpu(db_tok_string, valuep) &&
56 !db_value_of_name_vnet(db_tok_string, valuep)) {
57 db_error("Symbol not found\n");
63 *valuep = (db_expr_t)db_tok_number;
67 *valuep = (db_expr_t)db_dot;
71 *valuep = (db_expr_t)db_prev;
75 *valuep = (db_expr_t) db_next;
79 *valuep = (db_expr_t)db_last_addr;
83 if (!db_get_variable(valuep))
88 if (!db_expression(valuep)) {
89 db_error("Syntax error\n");
94 db_error("Syntax error\n");
104 db_unary(db_expr_t *valuep)
110 if (!db_unary(valuep)) {
111 db_error("Syntax error\n");
119 if (!db_unary(valuep)) {
120 db_error("Syntax error\n");
123 *valuep = db_get_value((db_addr_t)*valuep, sizeof(void *), FALSE);
127 return (db_term(valuep));
131 db_mult_expr(db_expr_t *valuep)
140 while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH) {
141 if (!db_term(&rhs)) {
142 db_error("Syntax error\n");
149 db_error("Divide by 0\n");
157 lhs = ((lhs+rhs-1)/rhs)*rhs;
167 db_add_expr(db_expr_t *valuep)
172 if (!db_mult_expr(&lhs))
176 while (t == tPLUS || t == tMINUS) {
177 if (!db_mult_expr(&rhs)) {
178 db_error("Syntax error\n");
193 db_shift_expr(db_expr_t *valuep)
198 if (!db_add_expr(&lhs))
202 while (t == tSHIFT_L || t == tSHIFT_R) {
203 if (!db_add_expr(&rhs)) {
204 db_error("Syntax error\n");
208 db_error("Negative shift amount\n");
214 /* Shift right is unsigned */
215 lhs = (unsigned) lhs >> rhs;
225 db_expression(db_expr_t *valuep)
227 return (db_shift_expr(valuep));