xref: /freebsd/sys/ddb/db_variables.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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 };
49 static struct db_variable *db_evars =
50 	db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
51 
52 static int
53 db_find_variable(struct db_variable **varp)
54 {
55 	struct db_variable *vp;
56 	int t;
57 
58 	t = db_read_token();
59 	if (t == tIDENT) {
60 		for (vp = db_vars; vp < db_evars; vp++) {
61 			if (!strcmp(db_tok_string, vp->name)) {
62 				*varp = vp;
63 				return (1);
64 			}
65 		}
66 		for (vp = db_regs; vp < db_eregs; vp++) {
67 			if (!strcmp(db_tok_string, vp->name)) {
68 				*varp = vp;
69 				return (1);
70 			}
71 		}
72 	}
73 	db_error("Unknown variable\n");
74 	return (0);
75 }
76 
77 int
78 db_get_variable(db_expr_t *valuep)
79 {
80 	struct db_variable *vp;
81 
82 	if (!db_find_variable(&vp))
83 		return (0);
84 
85 	return (db_read_variable(vp, valuep));
86 }
87 
88 int
89 db_set_variable(db_expr_t value)
90 {
91 	struct db_variable *vp;
92 
93 	if (!db_find_variable(&vp))
94 		return (0);
95 
96 	return (db_write_variable(vp, value));
97 }
98 
99 int
100 db_read_variable(struct db_variable *vp, db_expr_t *valuep)
101 {
102 	db_varfcn_t *func = vp->fcn;
103 
104 	if (func == FCN_NULL) {
105 		*valuep = *(vp->valuep);
106 		return (1);
107 	}
108 	return ((*func)(vp, valuep, DB_VAR_GET));
109 }
110 
111 int
112 db_write_variable(struct db_variable *vp, db_expr_t value)
113 {
114 	db_varfcn_t *func = vp->fcn;
115 
116 	if (func == FCN_NULL) {
117 		*(vp->valuep) = value;
118 		return (1);
119 	}
120 	return ((*func)(vp, &value, DB_VAR_SET));
121 }
122 
123 void
124 db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
125 {
126 	struct db_variable *vp;
127 	db_expr_t value;
128 	int t;
129 
130 	t = db_read_token();
131 	if (t != tDOLLAR) {
132 		db_error("Unknown variable\n");
133 		return;
134 	}
135 	if (!db_find_variable(&vp)) {
136 		db_error("Unknown variable\n");
137 		return;
138 	}
139 
140 	t = db_read_token();
141 	if (t != tEQ)
142 		db_unread_token(t);
143 
144 	if (!db_expression(&value)) {
145 		db_error("No value\n");
146 		return;
147 	}
148 	if (db_read_token() != tEOL)
149 		db_error("?\n");
150 
151 	db_write_variable(vp, value);
152 }
153