FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_output.c
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 * $FreeBSD: releng/5.1/sys/ddb/db_output.c 92756 2002-03-20 05:14:42Z alfred $
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 #include <sys/cons.h>
41
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 */
59 static int db_output_position = 0; /* output column */
60 static int db_last_non_space = 0; /* last non-space character */
61 db_expr_t 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)
64 db_expr_t db_max_width = 79; /* output line width */
65
66 static void db_putchar(int c, void *arg);
67
68 /*
69 * Force pending whitespace.
70 */
71 void
72 db_force_whitespace()
73 {
74 register int last_print, next_tab;
75
76 last_print = db_last_non_space;
77 while (last_print < db_output_position) {
78 next_tab = NEXT_TAB(last_print);
79 if (next_tab <= db_output_position) {
80 while (last_print < next_tab) { /* DON'T send a tab!!! */
81 cnputc(' ');
82 last_print++;
83 }
84 }
85 else {
86 cnputc(' ');
87 last_print++;
88 }
89 }
90 db_last_non_space = db_output_position;
91 }
92
93 /*
94 * Output character. Buffer whitespace.
95 */
96 static void
97 db_putchar(c, arg)
98 int c; /* character to output */
99 void * arg;
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 */
144 int
145 db_print_position()
146 {
147 return (db_output_position);
148 }
149
150 /*
151 * Printing
152 */
153 void
154 #if __STDC__
155 db_printf(const char *fmt, ...)
156 #else
157 db_printf(fmt)
158 const char *fmt;
159 #endif
160 {
161 va_list listp;
162
163 va_start(listp, fmt);
164 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
165 va_end(listp);
166 }
167
168 int db_indent;
169
170 void
171 #if __STDC__
172 db_iprintf(const char *fmt,...)
173 #else
174 db_iprintf(fmt)
175 const char *fmt;
176 #endif
177 {
178 register int i;
179 va_list listp;
180
181 for (i = db_indent; i >= 8; i -= 8)
182 db_printf("\t");
183 while (--i >= 0)
184 db_printf(" ");
185 va_start(listp, fmt);
186 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
187 va_end(listp);
188 }
189
190 /*
191 * End line if too long.
192 */
193 void
194 db_end_line()
195 {
196 if (db_output_position >= db_max_width)
197 db_printf("\n");
198 }
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