xref: /openbsd-src/sys/ddb/db_output.c (revision 1a8dbaac879b9f3335ad7fb25429ce63ac1d6bac)
1 /*	$OpenBSD: db_output.c,v 1.35 2020/10/15 03:14:00 deraadt Exp $	*/
2 /*	$NetBSD: db_output.c,v 1.13 1996/04/01 17:27:14 christos Exp $	*/
3 
4 /*
5  * Mach Operating System
6  * Copyright (c) 1993,1992,1991,1990 Carnegie Mellon University
7  * All Rights Reserved.
8  *
9  * Permission to use, copy, modify and distribute this software and its
10  * documentation is hereby granted, provided that both the copyright
11  * notice and this permission notice appear in all copies of the
12  * software, derivative works or modified versions, and any portions
13  * thereof, and that both notices appear in supporting documentation.
14  *
15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
17  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18  *
19  * Carnegie Mellon requests users of this software to return to
20  *
21  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
22  *  School of Computer Science
23  *  Carnegie Mellon University
24  *  Pittsburgh PA 15213-3890
25  *
26  * any improvements or extensions that they make and grant Carnegie Mellon
27  * the rights to redistribute these changes.
28  */
29 
30 /*
31  * Printf and character output for debugger.
32  */
33 #include <sys/param.h>
34 #include <sys/stdarg.h>
35 #include <sys/systm.h>
36 #include <sys/stacktrace.h>
37 
38 #include <dev/cons.h>
39 
40 #include <machine/db_machdep.h>
41 
42 #include <ddb/db_command.h>
43 #include <ddb/db_output.h>
44 #include <ddb/db_access.h>
45 #include <ddb/db_interface.h>
46 #include <ddb/db_sym.h>
47 #include <ddb/db_var.h>
48 
49 /*
50  *	Character output - tracks position in line.
51  *	To do this correctly, we should know how wide
52  *	the output device is - then we could zero
53  *	the line position when the output device wraps
54  *	around to the start of the next line.
55  *
56  *	Instead, we count the number of spaces printed
57  *	since the last printing character so that we
58  *	don't print trailing spaces.  This avoids most
59  *	of the wraparounds.
60  */
61 
62 #ifndef	DB_MAX_LINE
63 #define	DB_MAX_LINE		24	/* maximum line */
64 #define DB_MAX_WIDTH		80	/* maximum width */
65 #endif	/* DB_MAX_LINE */
66 
67 #define DB_MIN_MAX_WIDTH	20	/* minimum max width */
68 #define DB_MIN_MAX_LINE		3	/* minimum max line */
69 #define CTRL(c)			((c) & 0xff)
70 
71 int	db_output_position = 0;		/* output column */
72 int	db_output_line = 0;		/* output line number */
73 int	db_last_non_space = 0;		/* last non-space character */
74 int	db_tab_stop_width = 8;		/* how wide are tab stops? */
75 #define	NEXT_TAB(i) \
76 	((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
77 int	db_max_line = DB_MAX_LINE;	/* output max lines */
78 int	db_max_width = DB_MAX_WIDTH;	/* output line width */
79 int	db_radix = 16;			/* output numbers radix */
80 
81 static void db_more(void);
82 
83 /*
84  * Force pending whitespace.
85  */
86 void
87 db_force_whitespace(void)
88 {
89 	int last_print, next_tab;
90 
91 	last_print = db_last_non_space;
92 	while (last_print < db_output_position) {
93 		next_tab = NEXT_TAB(last_print);
94 		if (next_tab <= db_output_position) {
95 			while (last_print < next_tab) { /* DON'T send a tab!!! */
96 				cnputc(' ');
97 				last_print++;
98 			}
99 		} else {
100 			cnputc(' ');
101 			last_print++;
102 		}
103 	}
104 	db_last_non_space = db_output_position;
105 }
106 
107 static void
108 db_more(void)
109 {
110 	char *p;
111 	int quit_output = 0;
112 
113 	for (p = "--db_more--"; *p; p++)
114 		cnputc(*p);
115 	switch(cngetc()) {
116 	case ' ':
117 		db_output_line = 0;
118 		break;
119 	case 'q':
120 	case CTRL('c'):
121 		db_output_line = 0;
122 		quit_output = 1;
123 		break;
124 	default:
125 		db_output_line--;
126 		break;
127 	}
128 	p = "\b\b\b\b\b\b\b\b\b\b\b           \b\b\b\b\b\b\b\b\b\b\b";
129 	while (*p)
130 		cnputc(*p++);
131 	if (quit_output) {
132 		db_error(0);
133 		/* NOTREACHED */
134 	}
135 }
136 
137 /*
138  * Output character.  Buffer whitespace.
139  */
140 void
141 db_putchar(int c)
142 {
143 	if (db_max_line >= DB_MIN_MAX_LINE && db_output_line >= db_max_line-1)
144 		db_more();
145 
146 	if (c > ' ' && c <= '~') {
147 		/*
148 		 * Printing character.
149 		 * If we have spaces to print, print them first.
150 		 * Use tabs if possible.
151 		 */
152 		db_force_whitespace();
153 		cnputc(c);
154 		db_output_position++;
155 		if (db_max_width >= DB_MIN_MAX_WIDTH &&
156 		    db_output_position >= db_max_width-1) {
157 			/* auto new line */
158 			cnputc('\n');
159 			db_output_position = 0;
160 			db_last_non_space = 0;
161 			db_output_line++;
162 		}
163 		db_last_non_space = db_output_position;
164 	} else if (c == '\n') {
165 		/* Return */
166 		cnputc(c);
167 		db_output_position = 0;
168 		db_last_non_space = 0;
169 		db_output_line++;
170 	} else if (c == '\t') {
171 		/* assume tabs every 8 positions */
172 		db_output_position = NEXT_TAB(db_output_position);
173 	} else if (c == ' ') {
174 		/* space */
175 		db_output_position++;
176 	} else if (c == '\007') {
177 		/* bell */
178 		cnputc(c);
179 	}
180 	/* other characters are assumed non-printing */
181 }
182 
183 /*
184  * Return output position
185  */
186 int
187 db_print_position(void)
188 {
189 	return (db_output_position);
190 }
191 
192 /*
193  * End line if too long.
194  */
195 void
196 db_end_line(int space)
197 {
198 	if (db_output_position >= db_max_width - space)
199 		db_printf("\n");
200 }
201 
202 char *
203 db_format(char *buf, size_t bufsize, long val, int format, int alt, int width)
204 {
205 	const char *fmt;
206 
207 	if (format == DB_FORMAT_Z || db_radix == 16)
208 		fmt = alt ? "-%#*lx" : "-%*lx";
209 	else if (db_radix == 8)
210 		fmt = alt ? "-%#*lo" : "-%*lo";
211 	else
212 		fmt = alt ? "-%#*lu" : "-%*lu";
213 
214 	/* The leading '-' is a nasty (and beautiful) idea from NetBSD */
215 	if (val < 0 && format != DB_FORMAT_N)
216 		val = -val;
217 	else
218 		fmt++;
219 
220 	snprintf(buf, bufsize, fmt, width, val);
221 	return (buf);
222 }
223 
224 void
225 db_stack_dump(void)
226 {
227 	static volatile int intrace;
228 
229 	if (intrace) {
230 		printf("Faulted in traceback, aborting...\n");
231 		return;
232 	}
233 
234 	intrace = 1;
235 	printf("Starting stack trace...\n");
236 	db_stack_trace_print((db_expr_t)__builtin_frame_address(0), 1,
237 	    256 /* low limit */, "", printf);
238 	printf("End of stack trace.\n");
239 	intrace = 0;
240 }
241 
242 void
243 stacktrace_print(struct stacktrace *st, int (*pr)(const char *, ...))
244 {
245 	unsigned int i;
246 
247 	for (i = 0; i < st->st_count; i++) {
248 		(*pr)("#%-2u ", i);
249 		db_printsym(st->st_pc[i], DB_STGY_PROC, pr);
250 		(*pr)("\n");
251 	}
252 	if (st->st_count == 0)
253 		(*pr)("<empty stack trace>\n");
254 }
255