db_variables.c revision 50477 
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 * $FreeBSD: head/sys/ddb/db_variables.c 50477 1999-08-28 01:08:13Z peter $
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
37#include <ddb/ddb.h>
38#include <ddb/db_lex.h>
39#include <ddb/db_variables.h>
40
41static int	db_find_variable __P((struct db_variable **varp));
42static void	db_write_variable __P((struct db_variable *, db_expr_t *));
43
44#ifdef notused
45static int	db_set_variable __P((db_expr_t value));
46#endif
47
48static struct db_variable db_vars[] = {
49	{ "radix",	&db_radix, FCN_NULL },
50	{ "maxoff",	&db_maxoff, FCN_NULL },
51	{ "maxwidth",	&db_max_width, FCN_NULL },
52	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
53};
54static struct db_variable *db_evars =
55		db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
56
57static int
58db_find_variable(varp)
59	struct db_variable	**varp;
60{
61	int	t;
62	struct db_variable *vp;
63
64	t = db_read_token();
65	if (t == tIDENT) {
66	    for (vp = db_vars; vp < db_evars; vp++) {
67		if (!strcmp(db_tok_string, vp->name)) {
68		    *varp = vp;
69		    return (1);
70		}
71	    }
72	    for (vp = db_regs; vp < db_eregs; vp++) {
73		if (!strcmp(db_tok_string, vp->name)) {
74		    *varp = vp;
75		    return (1);
76		}
77	    }
78	}
79	db_error("Unknown variable\n");
80	return (0);
81}
82
83int
84db_get_variable(valuep)
85	db_expr_t	*valuep;
86{
87	struct db_variable *vp;
88
89	if (!db_find_variable(&vp))
90	    return (0);
91
92	db_read_variable(vp, valuep);
93
94	return (1);
95}
96
97#ifdef notused
98static int
99db_set_variable(value)
100	db_expr_t	value;
101{
102	struct db_variable *vp;
103
104	if (!db_find_variable(&vp))
105	    return (0);
106
107	db_write_variable(vp, &value);
108
109	return (1);
110}
111#endif
112
113void
114db_read_variable(vp, valuep)
115	struct db_variable *vp;
116	db_expr_t	*valuep;
117{
118	db_varfcn_t	*func = vp->fcn;
119
120	if (func == FCN_NULL)
121	    *valuep = *(vp->valuep);
122	else
123	    (*func)(vp, valuep, DB_VAR_GET);
124}
125
126static void
127db_write_variable(vp, valuep)
128	struct db_variable *vp;
129	db_expr_t	*valuep;
130{
131	db_varfcn_t	*func = vp->fcn;
132
133	if (func == FCN_NULL)
134	    *(vp->valuep) = *valuep;
135	else
136	    (*func)(vp, valuep, DB_VAR_SET);
137}
138
139void
140db_set_cmd(dummy1, dummy2, dummy3, dummy4)
141	db_expr_t	dummy1;
142	boolean_t	dummy2;
143	db_expr_t	dummy3;
144	char *		dummy4;
145{
146	db_expr_t	value;
147	struct db_variable *vp;
148	int	t;
149
150	t = db_read_token();
151	if (t != tDOLLAR) {
152	    db_error("Unknown variable\n");
153	    return;
154	}
155	if (!db_find_variable(&vp)) {
156	    db_error("Unknown variable\n");
157	    return;
158	}
159
160	t = db_read_token();
161	if (t != tEQ)
162	    db_unread_token(t);
163
164	if (!db_expression(&value)) {
165	    db_error("No value\n");
166	    return;
167	}
168	if (db_read_token() != tEOL) {
169	    db_error("?\n");
170	}
171
172	db_write_variable(vp, &value);
173}
174