db_variables.c revision 37504 
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 1.15 1998/06/07 17:09:38 dfr Exp $
27 */
28
29/*
30 * 	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33
34#include <sys/param.h>
35
36#include <ddb/ddb.h>
37#include <ddb/db_lex.h>
38#include <ddb/db_variables.h>
39
40static int	db_find_variable __P((struct db_variable **varp));
41static void	db_write_variable __P((struct db_variable *, db_expr_t *));
42
43#ifdef notused
44static int	db_set_variable __P((db_expr_t value));
45#endif
46
47static struct db_variable db_vars[] = {
48	{ "radix",	&db_radix, FCN_NULL },
49	{ "maxoff",	&db_maxoff, FCN_NULL },
50	{ "maxwidth",	&db_max_width, FCN_NULL },
51	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
52};
53static struct db_variable *db_evars =
54		db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
55
56static int
57db_find_variable(varp)
58	struct db_variable	**varp;
59{
60	int	t;
61	struct db_variable *vp;
62
63	t = db_read_token();
64	if (t == tIDENT) {
65	    for (vp = db_vars; vp < db_evars; vp++) {
66		if (!strcmp(db_tok_string, vp->name)) {
67		    *varp = vp;
68		    return (1);
69		}
70	    }
71	    for (vp = db_regs; vp < db_eregs; vp++) {
72		if (!strcmp(db_tok_string, vp->name)) {
73		    *varp = vp;
74		    return (1);
75		}
76	    }
77	}
78	db_error("Unknown variable\n");
79	return (0);
80}
81
82int
83db_get_variable(valuep)
84	db_expr_t	*valuep;
85{
86	struct db_variable *vp;
87
88	if (!db_find_variable(&vp))
89	    return (0);
90
91	db_read_variable(vp, valuep);
92
93	return (1);
94}
95
96#ifdef notused
97static int
98db_set_variable(value)
99	db_expr_t	value;
100{
101	struct db_variable *vp;
102
103	if (!db_find_variable(&vp))
104	    return (0);
105
106	db_write_variable(vp, &value);
107
108	return (1);
109}
110#endif
111
112void
113db_read_variable(vp, valuep)
114	struct db_variable *vp;
115	db_expr_t	*valuep;
116{
117	db_varfcn_t	*func = vp->fcn;
118
119	if (func == FCN_NULL)
120	    *valuep = *(vp->valuep);
121	else
122	    (*func)(vp, valuep, DB_VAR_GET);
123}
124
125static void
126db_write_variable(vp, valuep)
127	struct db_variable *vp;
128	db_expr_t	*valuep;
129{
130	db_varfcn_t	*func = vp->fcn;
131
132	if (func == FCN_NULL)
133	    *(vp->valuep) = *valuep;
134	else
135	    (*func)(vp, valuep, DB_VAR_SET);
136}
137
138void
139db_set_cmd(dummy1, dummy2, dummy3, dummy4)
140	db_expr_t	dummy1;
141	boolean_t	dummy2;
142	db_expr_t	dummy3;
143	char *		dummy4;
144{
145	db_expr_t	value;
146	struct db_variable *vp;
147	int	t;
148
149	t = db_read_token();
150	if (t != tDOLLAR) {
151	    db_error("Unknown variable\n");
152	    return;
153	}
154	if (!db_find_variable(&vp)) {
155	    db_error("Unknown variable\n");
156	    return;
157	}
158
159	t = db_read_token();
160	if (t != tEQ)
161	    db_unread_token(t);
162
163	if (!db_expression(&value)) {
164	    db_error("No value\n");
165	    return;
166	}
167	if (db_read_token() != tEOL) {
168	    db_error("?\n");
169	}
170
171	db_write_variable(vp, &value);
172}
173