xref: /freebsd/sys/ddb/db_variables.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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("$FreeBSD$");
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