db_variables.c revision 4 
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 * HISTORY
28 * $Log: db_variables.c,v $
29 * Revision 1.1  1992/03/25  21:45:33  pace
30 * Initial revision
31 *
32 * Revision 2.3  91/02/05  17:07:19  mrt
33 * 	Changed to new Mach copyright
34 * 	[91/01/31  16:19:46  mrt]
35 *
36 * Revision 2.2  90/08/27  21:53:24  dbg
37 * 	New db_read/write_variable functions.  Should be used instead
38 * 	of dereferencing valuep directly, which might not be a true
39 * 	pointer if there is an fcn() access function.
40 * 	[90/08/20            af]
41 *
42 * 	Fix declarations.
43 * 	Check for trailing garbage after last expression on command line.
44 * 	[90/08/10  14:34:54  dbg]
45 *
46 * 	Created.
47 * 	[90/07/25            dbg]
48 *
49 */
50/*
51 * 	Author: David B. Golub, Carnegie Mellon University
52 *	Date:	7/90
53 */
54
55#include "param.h"
56#include "proc.h"
57#include <machine/db_machdep.h>
58
59#include <ddb/db_lex.h>
60#include <ddb/db_variables.h>
61
62extern unsigned int	db_maxoff;
63
64extern int	db_radix;
65extern int	db_max_width;
66extern int	db_tab_stop_width;
67
68struct db_variable db_vars[] = {
69	{ "radix",	&db_radix, FCN_NULL },
70	{ "maxoff",	(int *)&db_maxoff, FCN_NULL },
71	{ "maxwidth",	&db_max_width, FCN_NULL },
72	{ "tabstops",	&db_tab_stop_width, FCN_NULL },
73};
74struct db_variable *db_evars = db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
75
76int
77db_find_variable(varp)
78	struct db_variable	**varp;
79{
80	int	t;
81	struct db_variable *vp;
82
83	t = db_read_token();
84	if (t == tIDENT) {
85	    for (vp = db_vars; vp < db_evars; vp++) {
86		if (!strcmp(db_tok_string, vp->name)) {
87		    *varp = vp;
88		    return (1);
89		}
90	    }
91	    for (vp = db_regs; vp < db_eregs; vp++) {
92		if (!strcmp(db_tok_string, vp->name)) {
93		    *varp = vp;
94		    return (1);
95		}
96	    }
97	}
98	db_error("Unknown variable\n");
99	return (0);
100}
101
102int
103db_get_variable(valuep)
104	db_expr_t	*valuep;
105{
106	struct db_variable *vp;
107
108	if (!db_find_variable(&vp))
109	    return (0);
110
111	db_read_variable(vp, valuep);
112
113	return (1);
114}
115
116int
117db_set_variable(value)
118	db_expr_t	value;
119{
120	struct db_variable *vp;
121
122	if (!db_find_variable(&vp))
123	    return (0);
124
125	db_write_variable(vp, &value);
126
127	return (1);
128}
129
130
131db_read_variable(vp, valuep)
132	struct db_variable *vp;
133	db_expr_t	*valuep;
134{
135	int	(*func)() = vp->fcn;
136
137	if (func == FCN_NULL)
138	    *valuep = *(vp->valuep);
139	else
140	    (*func)(vp, valuep, DB_VAR_GET);
141}
142
143db_write_variable(vp, valuep)
144	struct db_variable *vp;
145	db_expr_t	*valuep;
146{
147	int	(*func)() = vp->fcn;
148
149	if (func == FCN_NULL)
150	    *(vp->valuep) = *valuep;
151	else
152	    (*func)(vp, valuep, DB_VAR_SET);
153}
154
155void
156db_set_cmd()
157{
158	db_expr_t	value;
159	int	(*func)();
160	struct db_variable *vp;
161	int	t;
162
163	t = db_read_token();
164	if (t != tDOLLAR) {
165	    db_error("Unknown variable\n");
166	    return;
167	}
168	if (!db_find_variable(&vp)) {
169	    db_error("Unknown variable\n");
170	    return;
171	}
172
173	t = db_read_token();
174	if (t != tEQ)
175	    db_unread_token(t);
176
177	if (!db_expression(&value)) {
178	    db_error("No value\n");
179	    return;
180	}
181	if (db_read_token() != tEOL) {
182	    db_error("?\n");
183	}
184
185	db_write_variable(vp, &value);
186}
187