xref: /freebsd/sys/ddb/db_output.c (revision 7bd6fde3)
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 }
312