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.
26 * $FreeBSD: src/sys/ddb/db_expr.c,v 1.13 1999/08/28 00:41:07 peter Exp $
27 * $DragonFly: src/sys/ddb/db_expr.c,v 1.4 2005/12/23 21:35:44 swildner Exp $
31 * Author: David B. Golub, Carnegie Mellon University
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_error("Symbol not found\n");
61 *valuep = (db_expr_t)db_tok_number;
65 *valuep = (db_expr_t)db_dot;
69 *valuep = (db_expr_t)db_prev;
73 *valuep = (db_expr_t) db_next;
77 *valuep = (db_expr_t)db_last_addr;
81 if (!db_get_variable(valuep))
86 if (!db_expression(valuep)) {
87 db_error("Syntax error\n");
92 db_error("Syntax error\n");
102 db_unary(db_expr_t *valuep)
108 if (!db_unary(valuep)) {
109 db_error("Syntax error\n");
117 if (!db_unary(valuep)) {
118 db_error("Syntax error\n");
121 *valuep = db_get_value((db_addr_t)*valuep, sizeof(int), FALSE);
125 return (db_term(valuep));
129 db_mult_expr(db_expr_t *valuep)
138 while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH) {
139 if (!db_term(&rhs)) {
140 db_error("Syntax error\n");
147 db_error("Divide by 0\n");
155 lhs = ((lhs+rhs-1)/rhs)*rhs;
165 db_add_expr(db_expr_t *valuep)
170 if (!db_mult_expr(&lhs))
174 while (t == tPLUS || t == tMINUS) {
175 if (!db_mult_expr(&rhs)) {
176 db_error("Syntax error\n");
191 db_shift_expr(db_expr_t *valuep)
196 if (!db_add_expr(&lhs))
200 while (t == tSHIFT_L || t == tSHIFT_R) {
201 if (!db_add_expr(&rhs)) {
202 db_error("Syntax error\n");
206 db_error("Negative shift amount\n");
212 /* Shift right is unsigned */
213 lhs = (unsigned) lhs >> rhs;
223 db_expression(db_expr_t *valuep)
225 return (db_shift_expr(valuep));