FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_output.c
1 /* $NetBSD: db_output.c,v 1.36 2020/01/26 01:42:55 uwe Exp $ */
2
3 /*
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 */
28
29 /*
30 * Printf and character output for debugger.
31 */
32
33 #ifdef _KERNEL_OPT
34 #include "opt_ddbparam.h"
35 #endif
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: db_output.c,v 1.36 2020/01/26 01:42:55 uwe Exp $");
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/stdarg.h>
43
44 #include <dev/cons.h>
45
46 #include <ddb/ddb.h>
47
48 /*
49 * Character output - tracks position in line.
50 * To do this correctly, we should know how wide
51 * the output device is - then we could zero
52 * the line position when the output device wraps
53 * around to the start of the next line.
54 *
55 * Instead, we count the number of spaces printed
56 * since the last printing character so that we
57 * don't print trailing spaces. This avoids most
58 * of the wraparounds.
59 */
60
61 #ifndef DB_MAX_LINE
62 #define DB_MAX_LINE 24 /* maximum line */
63 #endif /* DB_MAX_LINE */
64 #ifndef DB_MAX_WIDTH
65 #define DB_MAX_WIDTH 80 /* maximum width */
66 #endif /* DB_MAX_WIDTH */
67
68 #define DB_MIN_MAX_WIDTH 20 /* minimum max width */
69 #define DB_MIN_MAX_LINE 3 /* minimum max line */
70 #define CTRL(c) ((c) & 0xff)
71
72 int db_output_line = 0; /* output line number */
73 int db_tab_stop_width = 8; /* how wide are tab stops? */
74 int db_max_line = DB_MAX_LINE; /* output max lines */
75 int db_max_width = DB_MAX_WIDTH; /* output line width */
76
77 static int db_output_position = 0; /* output column */
78 static int db_last_non_space = 0; /* last non-space character */
79
80 static void db_more(void);
81
82 /*
83 * Force pending whitespace.
84 */
85 void
86 db_force_whitespace(void)
87 {
88 int last_print, next_tab;
89
90 last_print = db_last_non_space;
91 while (last_print < db_output_position) {
92 next_tab = DB_NEXT_TAB(last_print);
93 if (next_tab <= db_output_position) {
94 while (last_print < next_tab) { /* DON'T send a tab!! */
95 cnputc(' ');
96 last_print++;
97 }
98 } else {
99 cnputc(' ');
100 last_print++;
101 }
102 }
103 db_last_non_space = db_output_position;
104 }
105
106
107 /*
108 * End the current line if it exceeds $maxwidth
109 */
110 static void
111 db_check_wrap(void)
112 {
113
114 if (db_max_width >= DB_MIN_MAX_WIDTH
115 && db_output_position >= db_max_width) {
116 cnputc('\n');
117 db_output_position = 0;
118 db_last_non_space = 0;
119 db_output_line++;
120 }
121 }
122
123
124 static void
125 db_more(void)
126 {
127 const char *p;
128 int quit_output = 0;
129
130 for (p = "--db_more--"; *p; p++)
131 cnputc(*p);
132 switch (cngetc()) {
133 case ' ':
134 db_output_line = 0;
135 break;
136 case 'q':
137 case CTRL('c'):
138 db_output_line = 0;
139 quit_output = 1;
140 break;
141 default:
142 db_output_line--;
143 break;
144 }
145 p = "\b\b\b\b\b\b\b\b\b\b\b \b\b\b\b\b\b\b\b\b\b\b";
146 while (*p)
147 cnputc(*p++);
148 if (quit_output) {
149 db_error(0);
150 /* NOTREACHED */
151 }
152 }
153
154 /*
155 * Output character. Buffer whitespace.
156 */
157 void
158 db_putchar(int c)
159 {
160 if (db_max_line >= DB_MIN_MAX_LINE && db_output_line >= db_max_line-1)
161 db_more();
162 if (c > ' ' && c <= '~') {
163 /*
164 * Printing character.
165 * If we have spaces to print, print them first.
166 * Use tabs if possible.
167 */
168 db_force_whitespace();
169 db_check_wrap();
170 cnputc(c);
171 db_output_position++;
172 db_check_wrap();
173 db_last_non_space = db_output_position;
174 } else if (c == '\n') {
175 /* Return */
176 cnputc(c);
177 db_output_position = 0;
178 db_last_non_space = 0;
179 db_output_line++;
180 db_check_interrupt();
181 } else if (c == '\t') {
182 /* assume tabs every 8 positions */
183 db_output_position = DB_NEXT_TAB(db_output_position);
184 } else if (c == ' ') {
185 /* space */
186 db_output_position++;
187 } else if (c == '\007') {
188 /* bell */
189 cnputc(c);
190 }
191 /* other characters are assumed non-printing */
192 }
193
194 /*
195 * Return output position
196 */
197 int
198 db_print_position(void)
199 {
200
201 return (db_output_position);
202 }
203
204 /*
205 * End line if too long.
206 */
207 void
208 db_end_line(void)
209 {
210
211 if (db_output_position >= db_max_width)
212 db_printf("\n");
213 }
214
215 /*
216 * Replacement for old '%r' kprintf format.
217 */
218 void
219 db_format_radix(char *buf, size_t bufsiz, quad_t val, int altflag)
220 {
221 const char *fmt;
222
223 if (db_radix == 16) {
224 db_format_hex(buf, bufsiz, val, altflag);
225 return;
226 }
227
228 if (db_radix == 8)
229 fmt = altflag ? "-%#qo" : "-%qo";
230 else
231 fmt = altflag ? "-%#qu" : "-%qu";
232
233 if (val < 0)
234 val = -val;
235 else
236 ++fmt;
237
238 snprintf(buf, bufsiz, fmt, val);
239 }
240
241 /*
242 * Replacement for old '%z' kprintf format.
243 */
244 void
245 db_format_hex(char *buf, size_t bufsiz, quad_t val, int altflag)
246 {
247 /* Only use alternate form if val is nonzero. */
248 const char *fmt = (altflag && val) ? "-%#qx" : "-%qx";
249
250 if (val < 0)
251 val = -val;
252 else
253 ++fmt;
254
255 snprintf(buf, bufsiz, fmt, val);
256 }
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