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 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) {
124 db_newlines++;
125 if (db_newlines >= db_maxlines)
126 db_pager();
127 }
128 return;
129 }
130
131 /* Otherwise, output data directly to the console. */
132 if (c > ' ' && c <= '~') {
133 /*
134 * Printing character.
135 * If we have spaces to print, print them first.
136 * Use tabs if possible.
137 */
138 db_force_whitespace();
139 cnputc(c);
140 db_output_position++;
141 db_last_non_space = db_output_position;
142 }
143 else if (c == '\n') {
144 /* Newline */
145 cnputc(c);
146 db_output_position = 0;
147 db_last_non_space = 0;
148 db_check_interrupt();
149 if (db_maxlines > 0) {
150 db_newlines++;
151 if (db_newlines >= db_maxlines)
152 db_pager();
153 }
154 }
155 else if (c == '\r') {
156 /* Return */
157 cnputc(c);
158 db_output_position = 0;
159 db_last_non_space = 0;
160 db_check_interrupt();
161 }
162 else if (c == '\t') {
163 /* assume tabs every 8 positions */
164 db_output_position = NEXT_TAB(db_output_position);
165 }
166 else if (c == ' ') {
167 /* space */
168 db_output_position++;
169 }
170 else if (c == '\007') {
171 /* bell */
172 cnputc(c);
173 }
174 /* other characters are assumed non-printing */
175 }
176
177 /*
178 * Turn on the pager.
179 */
180 void
181 db_enable_pager(void)
182 {
183 if (db_maxlines == 0) {
184 db_maxlines = db_lines_per_page;
185 db_newlines = 0;
186 db_pager_quit = 0;
187 }
188 }
189
190 /*
191 * Turn off the pager.
192 */
193 void
194 db_disable_pager(void)
195 {
196 db_maxlines = 0;
197 }
198
199 /*
200 * A simple paging callout function. It supports several simple more(1)-like
201 * commands as well as a quit command that sets db_pager_quit which db
202 * commands can poll to see if they should terminate early.
203 */
204 void
205 db_pager(void)
206 {
207 int c, done;
208
209 db_printf("--More--\r");
210 done = 0;
211 while (!done) {
212 c = cngetc();
213 switch (c) {
214 case 'e':
215 case 'j':
216 case '\n':
217 /* Just one more line. */
218 db_maxlines = 1;
219 done++;
220 break;
221 case 'd':
222 /* Half a page. */
223 db_maxlines = db_lines_per_page / 2;
224 done++;
225 break;
226 case 'f':
227 case ' ':
228 /* Another page. */
229 db_maxlines = db_lines_per_page;
230 done++;
231 break;
232 case 'q':
233 case 'Q':
234 case 'x':
235 case 'X':
236 /* Quit */
237 db_maxlines = 0;
238 db_pager_quit = 1;
239 done++;
240 break;
241 #if 0
242 /* FALLTHROUGH */
243 default:
244 cnputc('\007');
245 #endif
246 }
247 }
248 db_printf(" ");
249 db_force_whitespace();
250 db_printf("\r");
251 db_newlines = 0;
252 }
253
254 /*
255 * Return output position
256 */
257 int
258 db_print_position()
259 {
260 return (db_output_position);
261 }
262
263 /*
264 * Printing
265 */
266 void
267 #if __STDC__
268 db_printf(const char *fmt, ...)
269 #else
270 db_printf(fmt)
271 const char *fmt;
272 #endif
273 {
274 va_list listp;
275
276 va_start(listp, fmt);
277 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
278 va_end(listp);
279 }
280
281 int db_indent;
282
283 void
284 #if __STDC__
285 db_iprintf(const char *fmt,...)
286 #else
287 db_iprintf(fmt)
288 const char *fmt;
289 #endif
290 {
291 register int i;
292 va_list listp;
293
294 for (i = db_indent; i >= 8; i -= 8)
295 db_printf("\t");
296 while (--i >= 0)
297 db_printf(" ");
298 va_start(listp, fmt);
299 kvprintf (fmt, db_putchar, NULL, db_radix, listp);
300 va_end(listp);
301 }
302
303 /*
304 * End line if too long.
305 */
306 void
307 db_end_line(int field_width)
308 {
309 if (db_output_position + field_width > db_max_width)
310 db_printf("\n");
311 }
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