db_output.c revision 13446 
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_output.c,v 1.15 1995/12/10 19:08:03 bde Exp $
27 */
28
29/*
30 * 	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33
34/*
35 * Printf and character output for debugger.
36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40
41#include <machine/cons.h>
42#include <machine/stdarg.h>
43
44#include <ddb/ddb.h>
45#include <ddb/db_output.h>
46
47/*
48 *	Character output - tracks position in line.
49 *	To do this correctly, we should know how wide
50 *	the output device is - then we could zero
51 *	the line position when the output device wraps
52 *	around to the start of the next line.
53 *
54 *	Instead, we count the number of spaces printed
55 *	since the last printing character so that we
56 *	don't print trailing spaces.  This avoids most
57 *	of the wraparounds.
58 */
59static int	db_output_position = 0;		/* output column */
60static int	db_last_non_space = 0;		/* last non-space character */
61int	db_tab_stop_width = 8;		/* how wide are tab stops? */
62#define	NEXT_TAB(i) \
63	((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
64int	db_max_width = 80;		/* output line width */
65
66static char	*db_ksprintn __P((u_long ul, int base, int *lenp));
67static void	db_printf_guts __P((const char *, va_list));
68
69/*
70 * Force pending whitespace.
71 */
72void
73db_force_whitespace()
74{
75	register int last_print, next_tab;
76
77	last_print = db_last_non_space;
78	while (last_print < db_output_position) {
79	    next_tab = NEXT_TAB(last_print);
80	    if (next_tab <= db_output_position) {
81		while (last_print < next_tab) { /* DON'T send a tab!!! */
82			cnputc(' ');
83			last_print++;
84		}
85	    }
86	    else {
87		cnputc(' ');
88		last_print++;
89	    }
90	}
91	db_last_non_space = db_output_position;
92}
93
94/*
95 * Output character.  Buffer whitespace.
96 */
97void
98db_putchar(c)
99	int	c;		/* character to output */
100{
101	if (c > ' ' && c <= '~') {
102	    /*
103	     * Printing character.
104	     * If we have spaces to print, print them first.
105	     * Use tabs if possible.
106	     */
107	    db_force_whitespace();
108	    cnputc(c);
109	    db_output_position++;
110	    db_last_non_space = db_output_position;
111	}
112	else if (c == '\n') {
113	    /* Newline */
114	    cnputc(c);
115	    db_output_position = 0;
116	    db_last_non_space = 0;
117	    db_check_interrupt();
118	}
119	else if (c == '\r') {
120	    /* Return */
121	    cnputc(c);
122	    db_output_position = 0;
123	    db_last_non_space = 0;
124	    db_check_interrupt();
125	}
126	else if (c == '\t') {
127	    /* assume tabs every 8 positions */
128	    db_output_position = NEXT_TAB(db_output_position);
129	}
130	else if (c == ' ') {
131	    /* space */
132	    db_output_position++;
133	}
134	else if (c == '\007') {
135	    /* bell */
136	    cnputc(c);
137	}
138	/* other characters are assumed non-printing */
139}
140
141/*
142 * Return output position
143 */
144int
145db_print_position()
146{
147	return (db_output_position);
148}
149
150/*
151 * Printing
152 */
153void
154db_printf(const char *fmt, ...)
155{
156	va_list	listp;
157	va_start(listp, fmt);
158	kvprintf (fmt, db_putchar, NULL, db_radix, listp);
159	va_end(listp);
160}
161
162/*
163 * End line if too long.
164 */
165void
166db_end_line()
167{
168	if (db_output_position >= db_max_width)
169	    db_printf("\n");
170}
171
172/*
173 * Put a number (base <= 16) in a buffer in reverse order; return an
174 * optional length and a pointer to the NULL terminated (preceded?)
175 * buffer.
176 */
177static char *
178db_ksprintn(ul, base, lenp)
179	register u_long ul;
180	register int base, *lenp;
181{					/* A long in base 8, plus NULL. */
182	static char buf[sizeof(long) * NBBY / 3 + 2];
183	register char *p;
184
185	p = buf;
186	do {
187		*++p = "0123456789abcdef"[ul % base];
188	} while (ul /= base);
189	if (lenp)
190		*lenp = p - buf;
191	return (p);
192}
193