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: releng/5.4/sys/ddb/db_output.c 141016 2005-01-30 01:00:13Z imp $");
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 static int db_newlines; /* # lines this page */
70 static int db_maxlines = -1; /* max lines/page when paging */
71 static db_page_calloutfcn_t *db_page_callout = NULL;
72 static void *db_page_callout_arg = NULL;
73 static int ddb_use_printf = 0;
74 SYSCTL_INT(_debug, OID_AUTO, ddb_use_printf, CTLFLAG_RW, &ddb_use_printf, 0,
75 "use printf for all ddb output");
76
77 static void db_putchar(int c, void *arg);
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 last_print++;
94 }
95 }
96 else {
97 cnputc(' ');
98 last_print++;
99 }
100 }
101 db_last_non_space = db_output_position;
102 }
103
104 /*
105 * Output character. Buffer whitespace.
106 */
107 static void
108 db_putchar(c, arg)
109 int c; /* character to output */
110 void * arg;
111 {
112
113 /*
114 * If not in the debugger or the user requests it, output data to
115 * both the console and the message buffer.
116 */
117 if (!kdb_active || ddb_use_printf) {
118 printf("%c", c);
119 if (!kdb_active)
120 return;
121 if (c == '\r' || c == '\n')
122 db_check_interrupt();
123 if (c == '\n' && db_maxlines > 0 && db_page_callout != NULL) {
124 db_newlines++;
125 if (db_newlines >= db_maxlines) {
126 db_maxlines = -1;
127 db_page_callout(db_page_callout_arg);
128 }
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_output_position++;
143 db_last_non_space = db_output_position;
144 }
145 else if (c == '\n') {
146 /* Newline */
147 db_force_whitespace();
148 cnputc(c);
149 db_output_position = 0;
150 db_last_non_space = 0;
151 db_check_interrupt();
152 if (db_maxlines > 0 && db_page_callout != NULL) {
153 db_newlines++;
154 if (db_newlines >= db_maxlines) {
155 db_maxlines = -1;
156 db_page_callout(db_page_callout_arg);
157 }
158 }
159 }
160 else if (c == '\r') {
161 /* Return */
162 db_force_whitespace();
163 cnputc(c);
164 db_output_position = 0;
165 db_last_non_space = 0;
166 db_check_interrupt();
167 }
168 else if (c == '\t') {
169 /* assume tabs every 8 positions */
170 db_output_position = NEXT_TAB(db_output_position);
171 }
172 else if (c == ' ') {
173 /* space */
174 db_output_position++;
175 }
176 else if (c == '\007') {
177 /* bell */
178 cnputc(c);
179 }
180 /* other characters are assumed non-printing */
181 }
182
183 /*
184 * Register callout for providing a pager for output.
185 */
186 void
187 db_setup_paging(db_page_calloutfcn_t *callout, void *arg, int maxlines)
188 {
189
190 db_page_callout = callout;
191 db_page_callout_arg = arg;
192 db_maxlines = maxlines;
193 db_newlines = 0;
194 }
195
196 /*
197 * A simple paging callout function. If the argument is not null, it
198 * points to an integer that will be set to 1 if the user asks to quit.
199 */
200 void
201 db_simple_pager(void *arg)
202 {
203 int c, done;
204
205 db_printf("--More--\r");
206 done = 0;
207 while (!done) {
208 c = cngetc();
209 switch (c) {
210 case 'e':
211 case 'j':
212 case '\n':
213 /* Just one more line. */
214 db_setup_paging(db_simple_pager, arg, 1);
215 done++;
216 break;
217 case 'd':
218 /* Half a page. */
219 db_setup_paging(db_simple_pager, arg,
220 db_lines_per_page / 2);
221 done++;
222 break;
223 case 'f':
224 case ' ':
225 /* Another page. */
226 db_setup_paging(db_simple_pager, arg,
227 db_lines_per_page);
228 done++;
229 break;
230 case 'q':
231 case 'Q':
232 case 'x':
233 case 'X':
234 /* Quit */
235 if (arg != NULL) {
236 *(int *)arg = 1;
237 done++;
238 break;
239 }
240 #if 0
241 /* FALLTHROUGH */
242 default:
243 cnputc('\007');
244 #endif
245 }
246 }
247 db_printf(" \r");
248 }
249
250 /*
251 * Return output position
252 */
253 int
254 db_print_position()
255 {
256 return (db_output_position);
257 }
258
259 /*
260 * Printing
261 */
262 void
263 #if __STDC__
264 db_printf(const char *fmt, ...)
265 #else
266 db_printf(fmt)
267 const char *fmt;
268 #endif
269 {
270 va_list listp;
271
272 va_start(listp, fmt);
273 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
274 va_end(listp);
275 }
276
277 int db_indent;
278
279 void
280 #if __STDC__
281 db_iprintf(const char *fmt,...)
282 #else
283 db_iprintf(fmt)
284 const char *fmt;
285 #endif
286 {
287 register int i;
288 va_list listp;
289
290 for (i = db_indent; i >= 8; i -= 8)
291 db_printf("\t");
292 while (--i >= 0)
293 db_printf(" ");
294 va_start(listp, fmt);
295 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
296 va_end(listp);
297 }
298
299 /*
300 * End line if too long.
301 */
302 void
303 db_end_line()
304 {
305 if (db_output_position >= db_max_width)
306 db_printf("\n");
307 }
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