xref: /freebsd/sys/ddb/db_output.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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 }
320