xref: /freebsd/sys/ddb/db_variables.c (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
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 1.5 1994/08/18 22:34:27 wollman 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 
42 static void db_write_variable(struct db_variable *, db_expr_t *);
43 
44 struct 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 };
50 struct db_variable *db_evars = db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
51 
52 int
53 db_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 
78 int
79 db_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 
92 int
93 db_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 
107 void
108 db_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 
120 static void
121 db_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 
133 void
134 db_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