db_variables.c revision 12473 
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 *	$Id: db_variables.c,v 1.7 1995/05/30 07:57:17 rgrimes Exp $
27 */
28
29/*
30 * 	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/proc.h>
37#include <ddb/ddb.h>
38
39#include <ddb/db_lex.h>
40#include <ddb/db_variables.h>
41
42extern int	db_find_variable __P((struct db_variable **varp));
43extern int	db_set_variable __P((db_expr_t value));
44static void	db_write_variable __P((struct db_variable *, db_expr_t *));
45
46struct db_variable db_vars[] = {
47	{ "radix",	&db_radix, FCN_NULL },
48	{ "maxoff",	(int *)&db_maxoff, FCN_NULL },
49	{ "maxwidth",	&db_max_width, FCN_NULL },
50	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
51};
52struct db_variable *db_evars = db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
53
54int
55db_find_variable(varp)
56	struct db_variable	**varp;
57{
58	int	t;
59	struct db_variable *vp;
60
61	t = db_read_token();
62	if (t == tIDENT) {
63	    for (vp = db_vars; vp < db_evars; vp++) {
64		if (!strcmp(db_tok_string, vp->name)) {
65		    *varp = vp;
66		    return (1);
67		}
68	    }
69	    for (vp = db_regs; vp < db_eregs; vp++) {
70		if (!strcmp(db_tok_string, vp->name)) {
71		    *varp = vp;
72		    return (1);
73		}
74	    }
75	}
76	db_error("Unknown variable\n");
77	return (0);
78}
79
80int
81db_get_variable(valuep)
82	db_expr_t	*valuep;
83{
84	struct db_variable *vp;
85
86	if (!db_find_variable(&vp))
87	    return (0);
88
89	db_read_variable(vp, valuep);
90
91	return (1);
92}
93
94int
95db_set_variable(value)
96	db_expr_t	value;
97{
98	struct db_variable *vp;
99
100	if (!db_find_variable(&vp))
101	    return (0);
102
103	db_write_variable(vp, &value);
104
105	return (1);
106}
107
108
109void
110db_read_variable(vp, valuep)
111	struct db_variable *vp;
112	db_expr_t	*valuep;
113{
114	db_varfcn_t	*func = vp->fcn;
115
116	if (func == FCN_NULL)
117	    *valuep = *(vp->valuep);
118	else
119	    (*func)(vp, valuep, DB_VAR_GET);
120}
121
122static void
123db_write_variable(vp, valuep)
124	struct db_variable *vp;
125	db_expr_t	*valuep;
126{
127	db_varfcn_t	*func = vp->fcn;
128
129	if (func == FCN_NULL)
130	    *(vp->valuep) = *valuep;
131	else
132	    (*func)(vp, valuep, DB_VAR_SET);
133}
134
135void
136db_set_cmd(dummy1, dummy2, dummy3, dummy4)
137	db_expr_t	dummy1;
138	boolean_t	dummy2;
139	db_expr_t	dummy3;
140	char *		dummy4;
141{
142	db_expr_t	value;
143	struct db_variable *vp;
144	int	t;
145
146	t = db_read_token();
147	if (t != tDOLLAR) {
148	    db_error("Unknown variable\n");
149	    return;
150	}
151	if (!db_find_variable(&vp)) {
152	    db_error("Unknown variable\n");
153	    return;
154	}
155
156	t = db_read_token();
157	if (t != tEQ)
158	    db_unread_token(t);
159
160	if (!db_expression(&value)) {
161	    db_error("No value\n");
162	    return;
163	}
164	if (db_read_token() != tEOL) {
165	    db_error("?\n");
166	}
167
168	db_write_variable(vp, &value);
169}
170