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: src/sys/ddb/db_variables.c,v 1.23 2005/01/06 01:34:41 imp Exp $");
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
41 static int db_find_variable(struct db_variable **varp);
42
43 static 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 { "lines", &db_lines_per_page, FCN_NULL },
49 };
50 static struct db_variable *db_evars =
51 db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
52
53 static int
54 db_find_variable(struct db_variable **varp)
55 {
56 struct db_variable *vp;
57 int t;
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
78 int
79 db_get_variable(db_expr_t *valuep)
80 {
81 struct db_variable *vp;
82
83 if (!db_find_variable(&vp))
84 return (0);
85
86 return (db_read_variable(vp, valuep));
87 }
88
89 int
90 db_set_variable(db_expr_t value)
91 {
92 struct db_variable *vp;
93
94 if (!db_find_variable(&vp))
95 return (0);
96
97 return (db_write_variable(vp, value));
98 }
99
100 int
101 db_read_variable(struct db_variable *vp, db_expr_t *valuep)
102 {
103 db_varfcn_t *func = vp->fcn;
104
105 if (func == FCN_NULL) {
106 *valuep = *(vp->valuep);
107 return (1);
108 }
109 return ((*func)(vp, valuep, DB_VAR_GET));
110 }
111
112 int
113 db_write_variable(struct db_variable *vp, db_expr_t value)
114 {
115 db_varfcn_t *func = vp->fcn;
116
117 if (func == FCN_NULL) {
118 *(vp->valuep) = value;
119 return (1);
120 }
121 return ((*func)(vp, &value, DB_VAR_SET));
122 }
123
124 void
125 db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
126 {
127 struct db_variable *vp;
128 db_expr_t value;
129 int t;
130
131 t = db_read_token();
132 if (t != tDOLLAR) {
133 db_error("Unknown variable\n");
134 return;
135 }
136 if (!db_find_variable(&vp)) {
137 db_error("Unknown variable\n");
138 return;
139 }
140
141 t = db_read_token();
142 if (t != tEQ)
143 db_unread_token(t);
144
145 if (!db_expression(&value)) {
146 db_error("No value\n");
147 return;
148 }
149 if (db_read_token() != tEOL)
150 db_error("?\n");
151
152 db_write_variable(vp, value);
153 }
154
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