db_variables.c revision 131952 
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: head/sys/ddb/db_variables.c 131952 2004-07-10 23:47:20Z marcel $");
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};
49static struct db_variable *db_evars =
50	db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
51
52static int
53db_find_variable(struct db_variable **varp)
54{
55	struct db_variable *vp;
56	int t;
57
58	t = db_read_token();
59	if (t == tIDENT) {
60		for (vp = db_vars; vp < db_evars; vp++) {
61			if (!strcmp(db_tok_string, vp->name)) {
62				*varp = vp;
63				return (1);
64			}
65		}
66		for (vp = db_regs; vp < db_eregs; vp++) {
67			if (!strcmp(db_tok_string, vp->name)) {
68				*varp = vp;
69				return (1);
70			}
71		}
72	}
73	db_error("Unknown variable\n");
74	return (0);
75}
76
77int
78db_get_variable(db_expr_t *valuep)
79{
80	struct db_variable *vp;
81
82	if (!db_find_variable(&vp))
83		return (0);
84
85	return (db_read_variable(vp, valuep));
86}
87
88int
89db_set_variable(db_expr_t value)
90{
91	struct db_variable *vp;
92
93	if (!db_find_variable(&vp))
94		return (0);
95
96	return (db_write_variable(vp, value));
97}
98
99int
100db_read_variable(struct db_variable *vp, db_expr_t *valuep)
101{
102	db_varfcn_t *func = vp->fcn;
103
104	if (func == FCN_NULL) {
105		*valuep = *(vp->valuep);
106		return (1);
107	}
108	return ((*func)(vp, valuep, DB_VAR_GET));
109}
110
111int
112db_write_variable(struct db_variable *vp, db_expr_t value)
113{
114	db_varfcn_t *func = vp->fcn;
115
116	if (func == FCN_NULL) {
117		*(vp->valuep) = value;
118		return (1);
119	}
120	return ((*func)(vp, &value, DB_VAR_SET));
121}
122
123void
124db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
125{
126	struct db_variable *vp;
127	db_expr_t value;
128	int t;
129
130	t = db_read_token();
131	if (t != tDOLLAR) {
132		db_error("Unknown variable\n");
133		return;
134	}
135	if (!db_find_variable(&vp)) {
136		db_error("Unknown variable\n");
137		return;
138	}
139
140	t = db_read_token();
141	if (t != tEQ)
142		db_unread_token(t);
143
144	if (!db_expression(&value)) {
145		db_error("No value\n");
146		return;
147	}
148	if (db_read_token() != tEOL)
149		db_error("?\n");
150
151	db_write_variable(vp, value);
152}
153