2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
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7 * documentation is hereby granted, provided that both the copyright
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12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
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14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
16 * Carnegie Mellon requests users of this software to return to
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19 * School of Computer Science
20 * Carnegie Mellon University
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23 * any improvements or extensions that they make and grant Carnegie the
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26 * $FreeBSD: src/sys/ddb/db_expr.c,v 1.13 1999/08/28 00:41:07 peter Exp $
30 * Author: David B. Golub, Carnegie Mellon University
33 #include <sys/param.h>
36 #include <ddb/db_lex.h>
37 #include <ddb/db_access.h>
38 #include <ddb/db_command.h>
40 static boolean_t db_add_expr (db_expr_t *valuep);
41 static boolean_t db_mult_expr (db_expr_t *valuep);
42 static boolean_t db_shift_expr (db_expr_t *valuep);
43 static boolean_t db_term (db_expr_t *valuep);
44 static boolean_t db_unary (db_expr_t *valuep);
47 db_term(db_expr_t *valuep)
53 if (!db_value_of_name(db_tok_string, valuep)) {
54 db_error("Symbol not found\n");
60 *valuep = (db_expr_t)db_tok_number;
64 *valuep = (db_expr_t)db_dot;
68 *valuep = (db_expr_t)db_prev;
72 *valuep = (db_expr_t) db_next;
76 *valuep = (db_expr_t)db_last_addr;
80 if (!db_get_variable(valuep))
85 if (!db_expression(valuep)) {
86 db_error("Syntax error\n");
91 db_error("Syntax error\n");
101 db_unary(db_expr_t *valuep)
107 if (!db_unary(valuep)) {
108 db_error("Syntax error\n");
116 if (!db_unary(valuep)) {
117 db_error("Syntax error\n");
120 *valuep = db_get_value((db_addr_t)*valuep, sizeof(int), FALSE);
124 return (db_term(valuep));
128 db_mult_expr(db_expr_t *valuep)
133 *valuep = 0; /* silence gcc */
139 while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH) {
140 if (!db_term(&rhs)) {
141 db_error("Syntax error\n");
148 db_error("Divide by 0\n");
156 lhs = roundup(lhs, rhs);
166 db_add_expr(db_expr_t *valuep)
171 *valuep = 0; /* silence gcc */
173 if (!db_mult_expr(&lhs))
177 while (t == tPLUS || t == tMINUS) {
178 if (!db_mult_expr(&rhs)) {
179 db_error("Syntax error\n");
194 db_shift_expr(db_expr_t *valuep)
199 if (!db_add_expr(&lhs))
203 while (t == tSHIFT_L || t == tSHIFT_R) {
204 if (!db_add_expr(&rhs)) {
205 db_error("Syntax error\n");
209 db_error("Negative shift amount\n");
215 /* Shift right is unsigned */
216 lhs = (unsigned) lhs >> rhs;
226 db_expression(db_expr_t *valuep)
228 return (db_shift_expr(valuep));