db_variables.c revision 259065 
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/*
27 * 	Author: David B. Golub, Carnegie Mellon University
28 *	Date:	7/90
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/9/sys/ddb/db_variables.c 195699 2009-07-14 22:48:30Z rwatson $");
33
34#include <sys/param.h>
35#include <sys/systm.h>
36
37#include <ddb/ddb.h>
38#include <ddb/db_lex.h>
39#include <ddb/db_variables.h>
40
41static int	db_find_variable(struct db_variable **varp);
42
43static struct db_variable db_vars[] = {
44	{ "radix",	&db_radix, FCN_NULL },
45	{ "maxoff",	&db_maxoff, FCN_NULL },
46	{ "maxwidth",	&db_max_width, FCN_NULL },
47	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
48	{ "lines",	&db_lines_per_page, FCN_NULL },
49	{ "curcpu",	NULL, db_var_curcpu },
50	{ "db_cpu",	NULL, db_var_db_cpu },
51#ifdef VIMAGE
52	{ "curvnet",	NULL, db_var_curvnet },
53	{ "db_vnet",	NULL, db_var_db_vnet },
54#endif
55};
56static struct db_variable *db_evars =
57	db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
58
59static int
60db_find_variable(struct db_variable **varp)
61{
62	struct db_variable *vp;
63	int t;
64
65	t = db_read_token();
66	if (t == tIDENT) {
67		for (vp = db_vars; vp < db_evars; vp++) {
68			if (!strcmp(db_tok_string, vp->name)) {
69				*varp = vp;
70				return (1);
71			}
72		}
73		for (vp = db_regs; vp < db_eregs; vp++) {
74			if (!strcmp(db_tok_string, vp->name)) {
75				*varp = vp;
76				return (1);
77			}
78		}
79	}
80	db_error("Unknown variable\n");
81	return (0);
82}
83
84int
85db_get_variable(db_expr_t *valuep)
86{
87	struct db_variable *vp;
88
89	if (!db_find_variable(&vp))
90		return (0);
91
92	return (db_read_variable(vp, valuep));
93}
94
95int
96db_set_variable(db_expr_t value)
97{
98	struct db_variable *vp;
99
100	if (!db_find_variable(&vp))
101		return (0);
102
103	return (db_write_variable(vp, value));
104}
105
106int
107db_read_variable(struct db_variable *vp, db_expr_t *valuep)
108{
109	db_varfcn_t *func = vp->fcn;
110
111	if (func == FCN_NULL) {
112		*valuep = *(vp->valuep);
113		return (1);
114	}
115	return ((*func)(vp, valuep, DB_VAR_GET));
116}
117
118int
119db_write_variable(struct db_variable *vp, db_expr_t value)
120{
121	db_varfcn_t *func = vp->fcn;
122
123	if (func == FCN_NULL) {
124		*(vp->valuep) = value;
125		return (1);
126	}
127	return ((*func)(vp, &value, DB_VAR_SET));
128}
129
130void
131db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
132{
133	struct db_variable *vp;
134	db_expr_t value;
135	int t;
136
137	t = db_read_token();
138	if (t != tDOLLAR) {
139		db_error("Unknown variable\n");
140		return;
141	}
142	if (!db_find_variable(&vp)) {
143		db_error("Unknown variable\n");
144		return;
145	}
146
147	t = db_read_token();
148	if (t != tEQ)
149		db_unread_token(t);
150
151	if (!db_expression(&value)) {
152		db_error("No value\n");
153		return;
154	}
155	if (db_read_token() != tEOL)
156		db_error("?\n");
157
158	db_write_variable(vp, value);
159}
160