db_variables.c revision 8876 
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 1.6 1994/09/27 03:34:58 phk 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 void db_write_variable(struct db_variable *, db_expr_t *);
43
44struct db_variable db_vars[] = {
45	{ "radix",	&db_radix, FCN_NULL },
46	{ "maxoff",	(int *)&db_maxoff, FCN_NULL },
47	{ "maxwidth",	&db_max_width, FCN_NULL },
48	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
49};
50struct db_variable *db_evars = db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
51
52int
53db_find_variable(varp)
54	struct db_variable	**varp;
55{
56	int	t;
57	struct db_variable *vp;
58
59	t = db_read_token();
60	if (t == tIDENT) {
61	    for (vp = db_vars; vp < db_evars; vp++) {
62		if (!strcmp(db_tok_string, vp->name)) {
63		    *varp = vp;
64		    return (1);
65		}
66	    }
67	    for (vp = db_regs; vp < db_eregs; vp++) {
68		if (!strcmp(db_tok_string, vp->name)) {
69		    *varp = vp;
70		    return (1);
71		}
72	    }
73	}
74	db_error("Unknown variable\n");
75	return (0);
76}
77
78int
79db_get_variable(valuep)
80	db_expr_t	*valuep;
81{
82	struct db_variable *vp;
83
84	if (!db_find_variable(&vp))
85	    return (0);
86
87	db_read_variable(vp, valuep);
88
89	return (1);
90}
91
92int
93db_set_variable(value)
94	db_expr_t	value;
95{
96	struct db_variable *vp;
97
98	if (!db_find_variable(&vp))
99	    return (0);
100
101	db_write_variable(vp, &value);
102
103	return (1);
104}
105
106
107void
108db_read_variable(vp, valuep)
109	struct db_variable *vp;
110	db_expr_t	*valuep;
111{
112	int	(*func)() = vp->fcn;
113
114	if (func == FCN_NULL)
115	    *valuep = *(vp->valuep);
116	else
117	    (*func)(vp, valuep, DB_VAR_GET);
118}
119
120static void
121db_write_variable(vp, valuep)
122	struct db_variable *vp;
123	db_expr_t	*valuep;
124{
125	int	(*func)() = vp->fcn;
126
127	if (func == FCN_NULL)
128	    *(vp->valuep) = *valuep;
129	else
130	    (*func)(vp, valuep, DB_VAR_SET);
131}
132
133void
134db_set_cmd(db_expr_t dummy1, int dummy2, db_expr_t dummy3, char *dummy4)
135{
136	db_expr_t	value;
137	struct db_variable *vp;
138	int	t;
139
140	t = db_read_token();
141	if (t != tDOLLAR) {
142	    db_error("Unknown variable\n");
143	    return;
144	}
145	if (!db_find_variable(&vp)) {
146	    db_error("Unknown variable\n");
147	    return;
148	}
149
150	t = db_read_token();
151	if (t != tEQ)
152	    db_unread_token(t);
153
154	if (!db_expression(&value)) {
155	    db_error("No value\n");
156	    return;
157	}
158	if (db_read_token() != tEOL) {
159	    db_error("?\n");
160	}
161
162	db_write_variable(vp, &value);
163}
164