xref: /freebsd/sys/ddb/db_output.c (revision 37224cd3fcb911d440e40dd8e1f31652e2452537)
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 static int	db_newlines;			/* # lines this page */
69 static int	db_maxlines = -1;		/* max lines per page */
70 static db_page_calloutfcn_t *db_page_callout = NULL;
71 static void	*db_page_callout_arg = NULL;
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 
78 /*
79  * Force pending whitespace.
80  */
81 void
82 db_force_whitespace()
83 {
84 	register int last_print, next_tab;
85 
86 	last_print = db_last_non_space;
87 	while (last_print < db_output_position) {
88 	    next_tab = NEXT_TAB(last_print);
89 	    if (next_tab <= db_output_position) {
90 		while (last_print < next_tab) { /* DON'T send a tab!!! */
91 			cnputc(' ');
92 			last_print++;
93 		}
94 	    }
95 	    else {
96 		cnputc(' ');
97 		last_print++;
98 	    }
99 	}
100 	db_last_non_space = db_output_position;
101 }
102 
103 /*
104  * Output character.  Buffer whitespace.
105  */
106 static void
107 db_putchar(c, arg)
108 	int	c;		/* character to output */
109 	void *	arg;
110 {
111 
112 	/*
113 	 * If not in the debugger or the user requests it, output data to
114 	 * both the console and the message buffer.
115 	 */
116 	if (!kdb_active || ddb_use_printf) {
117 		printf("%c", c);
118 		if (!kdb_active)
119 			return;
120 		if (c == '\r' || c == '\n')
121 			db_check_interrupt();
122 		if (c == '\n' && db_maxlines > 0 && db_page_callout != NULL) {
123 			db_newlines++;
124 			if (db_newlines >= db_maxlines) {
125 				db_maxlines = -1;
126 				db_page_callout(db_page_callout_arg);
127 			}
128 		}
129 		return;
130 	}
131 
132 	/* Otherwise, output data directly to the console. */
133 	if (c > ' ' && c <= '~') {
134 	    /*
135 	     * Printing character.
136 	     * If we have spaces to print, print them first.
137 	     * Use tabs if possible.
138 	     */
139 	    db_force_whitespace();
140 	    cnputc(c);
141 	    db_output_position++;
142 	    db_last_non_space = db_output_position;
143 	}
144 	else if (c == '\n') {
145 	    /* Newline */
146 	    cnputc(c);
147 	    db_output_position = 0;
148 	    db_last_non_space = 0;
149 	    db_check_interrupt();
150 	    if (db_maxlines > 0 && db_page_callout != NULL) {
151 		    db_newlines++;
152 		    if (db_newlines >= db_maxlines) {
153 			    db_maxlines = -1;
154 			    db_page_callout(db_page_callout_arg);
155 		    }
156 	    }
157 	}
158 	else if (c == '\r') {
159 	    /* Return */
160 	    cnputc(c);
161 	    db_output_position = 0;
162 	    db_last_non_space = 0;
163 	    db_check_interrupt();
164 	}
165 	else if (c == '\t') {
166 	    /* assume tabs every 8 positions */
167 	    db_output_position = NEXT_TAB(db_output_position);
168 	}
169 	else if (c == ' ') {
170 	    /* space */
171 	    db_output_position++;
172 	}
173 	else if (c == '\007') {
174 	    /* bell */
175 	    cnputc(c);
176 	}
177 	/* other characters are assumed non-printing */
178 }
179 
180 /*
181  * Register callout for providing a pager for output.
182  */
183 void
184 db_setup_paging(db_page_calloutfcn_t *callout, void *arg, int maxlines)
185 {
186 
187 	db_page_callout = callout;
188 	db_page_callout_arg = arg;
189 	db_maxlines = maxlines;
190 	db_newlines = 0;
191 }
192 
193 /*
194  * A simple paging callout function.  If the argument is not null, it
195  * points to an integer that will be set to 1 if the user asks to quit.
196  */
197 void
198 db_simple_pager(void *arg)
199 {
200 	int c;
201 
202 	db_printf("--More--\r");
203 	for (;;) {
204 		c = cngetc();
205 		switch (c) {
206 		case '\n':
207 			/* Just one more line. */
208 			db_setup_paging(db_simple_pager, arg, 1);
209 			return;
210 		case ' ':
211 			/* Another page. */
212 			db_setup_paging(db_simple_pager, arg,
213 			    DB_LINES_PER_PAGE);
214 			return;
215 		case 'q':
216 		case 'Q':
217 		case 'x':
218 		case 'X':
219 			/* Quit */
220 			if (arg != NULL) {
221 				*(int *)arg = 1;
222 				db_printf("\n");
223 				return;
224 			}
225 #if 0
226 			/* FALLTHROUGH */
227 		default:
228 			cnputc('\007');
229 #endif
230 		}
231 	}
232 }
233 
234 /*
235  * Return output position
236  */
237 int
238 db_print_position()
239 {
240 	return (db_output_position);
241 }
242 
243 /*
244  * Printing
245  */
246 void
247 #if __STDC__
248 db_printf(const char *fmt, ...)
249 #else
250 db_printf(fmt)
251 	const char *fmt;
252 #endif
253 {
254 	va_list	listp;
255 
256 	va_start(listp, fmt);
257 	kvprintf (fmt, db_putchar, NULL, db_radix, listp);
258 	va_end(listp);
259 }
260 
261 int db_indent;
262 
263 void
264 #if __STDC__
265 db_iprintf(const char *fmt,...)
266 #else
267 db_iprintf(fmt)
268 	const char *fmt;
269 #endif
270 {
271 	register int i;
272 	va_list listp;
273 
274 	for (i = db_indent; i >= 8; i -= 8)
275 		db_printf("\t");
276 	while (--i >= 0)
277 		db_printf(" ");
278 	va_start(listp, fmt);
279 	kvprintf (fmt, db_putchar, NULL, db_radix, listp);
280 	va_end(listp);
281 }
282 
283 /*
284  * End line if too long.
285  */
286 void
287 db_end_line()
288 {
289 	if (db_output_position >= db_max_width)
290 	    db_printf("\n");
291 }
292