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 /*
27 * Author: David B. Golub, Carnegie Mellon University
28 * Date: 7/90
29 */
30
31 /*
32 * Printf and character output for debugger.
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/cons.h>
41 #include <sys/kdb.h>
42 #include <sys/kernel.h>
43 #include <sys/sysctl.h>
44
45 #include <machine/stdarg.h>
46
47 #include <ddb/ddb.h>
48 #include <ddb/db_output.h>
49
50 /*
51 * Character output - tracks position in line.
52 * To do this correctly, we should know how wide
53 * the output device is - then we could zero
54 * the line position when the output device wraps
55 * around to the start of the next line.
56 *
57 * Instead, we count the number of spaces printed
58 * since the last printing character so that we
59 * don't print trailing spaces. This avoids most
60 * of the wraparounds.
61 */
62 static int db_output_position = 0; /* output column */
63 static int db_last_non_space = 0; /* last non-space character */
64 db_expr_t db_tab_stop_width = 8; /* how wide are tab stops? */
65 #define NEXT_TAB(i) \
66 ((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
67 db_expr_t db_max_width = 79; /* output line width */
68 db_expr_t db_lines_per_page = 20; /* lines per page */
69 volatile int db_pager_quit; /* user requested quit */
70 static int db_newlines; /* # lines this page */
71 static int db_maxlines; /* max lines/page when paging */
72 static int ddb_use_printf = 0;
73 SYSCTL_INT(_debug, OID_AUTO, ddb_use_printf, CTLFLAG_RW, &ddb_use_printf, 0,
74 "use printf for all ddb output");
75
76 static void db_putchar(int c, void *arg);
77 static void db_pager(void);
78
79 /*
80 * Force pending whitespace.
81 */
82 void
83 db_force_whitespace()
84 {
85 register int last_print, next_tab;
86
87 last_print = db_last_non_space;
88 while (last_print < db_output_position) {
89 next_tab = NEXT_TAB(last_print);
90 if (next_tab <= db_output_position) {
91 while (last_print < next_tab) { /* DON'T send a tab!!! */
92 cnputc(' ');
93 db_capture_writech(' ');
94 last_print++;
95 }
96 }
97 else {
98 cnputc(' ');
99 db_capture_writech(' ');
100 last_print++;
101 }
102 }
103 db_last_non_space = db_output_position;
104 }
105
106 /*
107 * Output character. Buffer whitespace.
108 */
109 static void
110 db_putchar(c, arg)
111 int c; /* character to output */
112 void * arg;
113 {
114
115 /*
116 * If not in the debugger or the user requests it, output data to
117 * both the console and the message buffer.
118 */
119 if (!kdb_active || ddb_use_printf) {
120 printf("%c", c);
121 if (!kdb_active)
122 return;
123 if (c == '\r' || c == '\n')
124 db_check_interrupt();
125 if (c == '\n' && db_maxlines > 0) {
126 db_newlines++;
127 if (db_newlines >= db_maxlines)
128 db_pager();
129 }
130 return;
131 }
132
133 /* Otherwise, output data directly to the console. */
134 if (c > ' ' && c <= '~') {
135 /*
136 * Printing character.
137 * If we have spaces to print, print them first.
138 * Use tabs if possible.
139 */
140 db_force_whitespace();
141 cnputc(c);
142 db_capture_writech(c);
143 db_output_position++;
144 db_last_non_space = db_output_position;
145 }
146 else if (c == '\n') {
147 /* Newline */
148 cnputc(c);
149 db_capture_writech(c);
150 db_output_position = 0;
151 db_last_non_space = 0;
152 db_check_interrupt();
153 if (db_maxlines > 0) {
154 db_newlines++;
155 if (db_newlines >= db_maxlines)
156 db_pager();
157 }
158 }
159 else if (c == '\r') {
160 /* Return */
161 cnputc(c);
162 db_capture_writech(c);
163 db_output_position = 0;
164 db_last_non_space = 0;
165 db_check_interrupt();
166 }
167 else if (c == '\t') {
168 /* assume tabs every 8 positions */
169 db_output_position = NEXT_TAB(db_output_position);
170 }
171 else if (c == ' ') {
172 /* space */
173 db_output_position++;
174 }
175 else if (c == '\007') {
176 /* bell */
177 cnputc(c);
178 /* No need to beep in a log: db_capture_writech(c); */
179 }
180 /* other characters are assumed non-printing */
181 }
182
183 /*
184 * Turn on the pager.
185 */
186 void
187 db_enable_pager(void)
188 {
189 if (db_maxlines == 0) {
190 db_maxlines = db_lines_per_page;
191 db_newlines = 0;
192 db_pager_quit = 0;
193 }
194 }
195
196 /*
197 * Turn off the pager.
198 */
199 void
200 db_disable_pager(void)
201 {
202 db_maxlines = 0;
203 }
204
205 /*
206 * A simple paging callout function. It supports several simple more(1)-like
207 * commands as well as a quit command that sets db_pager_quit which db
208 * commands can poll to see if they should terminate early.
209 */
210 void
211 db_pager(void)
212 {
213 int c, done;
214
215 db_capture_enterpager();
216 db_printf("--More--\r");
217 done = 0;
218 while (!done) {
219 c = cngetc();
220 switch (c) {
221 case 'e':
222 case 'j':
223 case '\n':
224 /* Just one more line. */
225 db_maxlines = 1;
226 done++;
227 break;
228 case 'd':
229 /* Half a page. */
230 db_maxlines = db_lines_per_page / 2;
231 done++;
232 break;
233 case 'f':
234 case ' ':
235 /* Another page. */
236 db_maxlines = db_lines_per_page;
237 done++;
238 break;
239 case 'q':
240 case 'Q':
241 case 'x':
242 case 'X':
243 /* Quit */
244 db_maxlines = 0;
245 db_pager_quit = 1;
246 done++;
247 break;
248 #if 0
249 /* FALLTHROUGH */
250 default:
251 cnputc('\007');
252 #endif
253 }
254 }
255 db_printf(" ");
256 db_force_whitespace();
257 db_printf("\r");
258 db_newlines = 0;
259 db_capture_exitpager();
260 }
261
262 /*
263 * Return output position
264 */
265 int
266 db_print_position()
267 {
268 return (db_output_position);
269 }
270
271 /*
272 * Printing
273 */
274 void
275 #if __STDC__
276 db_printf(const char *fmt, ...)
277 #else
278 db_printf(fmt)
279 const char *fmt;
280 #endif
281 {
282 va_list listp;
283
284 va_start(listp, fmt);
285 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
286 va_end(listp);
287 }
288
289 int db_indent;
290
291 void
292 #if __STDC__
293 db_iprintf(const char *fmt,...)
294 #else
295 db_iprintf(fmt)
296 const char *fmt;
297 #endif
298 {
299 register int i;
300 va_list listp;
301
302 for (i = db_indent; i >= 8; i -= 8)
303 db_printf("\t");
304 while (--i >= 0)
305 db_printf(" ");
306 va_start(listp, fmt);
307 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
308 va_end(listp);
309 }
310
311 /*
312 * End line if too long.
313 */
314 void
315 db_end_line(int field_width)
316 {
317 if (db_output_position + field_width > db_max_width)
318 db_printf("\n");
319 }
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