db_variables.c revision 12515 
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 1.8 1995/11/24 14:13:41 bde 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
42static int	db_find_variable __P((struct db_variable **varp));
43static void	db_write_variable __P((struct db_variable *, db_expr_t *));
44
45#ifdef notused
46static int	db_set_variable __P((db_expr_t value));
47#endif
48
49static struct db_variable db_vars[] = {
50	{ "radix",	&db_radix, FCN_NULL },
51	{ "maxoff",	(int *)&db_maxoff, FCN_NULL },
52	{ "maxwidth",	&db_max_width, FCN_NULL },
53	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
54};
55static struct db_variable *db_evars =
56		db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
57
58static int
59db_find_variable(varp)
60	struct db_variable	**varp;
61{
62	int	t;
63	struct db_variable *vp;
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(valuep)
86	db_expr_t	*valuep;
87{
88	struct db_variable *vp;
89
90	if (!db_find_variable(&vp))
91	    return (0);
92
93	db_read_variable(vp, valuep);
94
95	return (1);
96}
97
98#ifdef notused
99static int
100db_set_variable(value)
101	db_expr_t	value;
102{
103	struct db_variable *vp;
104
105	if (!db_find_variable(&vp))
106	    return (0);
107
108	db_write_variable(vp, &value);
109
110	return (1);
111}
112#endif
113
114void
115db_read_variable(vp, valuep)
116	struct db_variable *vp;
117	db_expr_t	*valuep;
118{
119	db_varfcn_t	*func = vp->fcn;
120
121	if (func == FCN_NULL)
122	    *valuep = *(vp->valuep);
123	else
124	    (*func)(vp, valuep, DB_VAR_GET);
125}
126
127static void
128db_write_variable(vp, valuep)
129	struct db_variable *vp;
130	db_expr_t	*valuep;
131{
132	db_varfcn_t	*func = vp->fcn;
133
134	if (func == FCN_NULL)
135	    *(vp->valuep) = *valuep;
136	else
137	    (*func)(vp, valuep, DB_VAR_SET);
138}
139
140void
141db_set_cmd(dummy1, dummy2, dummy3, dummy4)
142	db_expr_t	dummy1;
143	boolean_t	dummy2;
144	db_expr_t	dummy3;
145	char *		dummy4;
146{
147	db_expr_t	value;
148	struct db_variable *vp;
149	int	t;
150
151	t = db_read_token();
152	if (t != tDOLLAR) {
153	    db_error("Unknown variable\n");
154	    return;
155	}
156	if (!db_find_variable(&vp)) {
157	    db_error("Unknown variable\n");
158	    return;
159	}
160
161	t = db_read_token();
162	if (t != tEQ)
163	    db_unread_token(t);
164
165	if (!db_expression(&value)) {
166	    db_error("No value\n");
167	    return;
168	}
169	if (db_read_token() != tEOL) {
170	    db_error("?\n");
171	}
172
173	db_write_variable(vp, &value);
174}
175