xref: /netbsd-src/sys/ddb/db_output.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: db_output.c,v 1.17 1997/10/24 18:20:23 chuck Exp $	*/
2 
3 /*
4  * Mach Operating System
5  * Copyright (c) 1991,1990 Carnegie Mellon University
6  * All Rights Reserved.
7  *
8  * Permission to use, copy, modify and distribute this software and its
9  * documentation is hereby granted, provided that both the copyright
10  * notice and this permission notice appear in all copies of the
11  * software, derivative works or modified versions, and any portions
12  * thereof, and that both notices appear in supporting documentation.
13  *
14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17  *
18  * Carnegie Mellon requests users of this software to return to
19  *
20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
21  *  School of Computer Science
22  *  Carnegie Mellon University
23  *  Pittsburgh PA 15213-3890
24  *
25  * any improvements or extensions that they make and grant Carnegie the
26  * rights to redistribute these changes.
27  */
28 
29 /*
30  * Printf and character output for debugger.
31  */
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 
35 #include <machine/stdarg.h>
36 
37 #include <dev/cons.h>
38 
39 #include <machine/db_machdep.h>
40 
41 #include <ddb/db_command.h>
42 #include <ddb/db_output.h>
43 #include <ddb/db_interface.h>
44 #include <ddb/db_sym.h>
45 #include <ddb/db_extern.h>
46 
47 /*
48  *	Character output - tracks position in line.
49  *	To do this correctly, we should know how wide
50  *	the output device is - then we could zero
51  *	the line position when the output device wraps
52  *	around to the start of the next line.
53  *
54  *	Instead, we count the number of spaces printed
55  *	since the last printing character so that we
56  *	don't print trailing spaces.  This avoids most
57  *	of the wraparounds.
58  */
59 
60 #ifndef	DB_MAX_LINE
61 #define	DB_MAX_LINE		24	/* maximum line */
62 #define DB_MAX_WIDTH		80	/* maximum width */
63 #endif	DB_MAX_LINE
64 
65 #define DB_MIN_MAX_WIDTH	20	/* minimum max width */
66 #define DB_MIN_MAX_LINE		3	/* minimum max line */
67 #define CTRL(c)			((c) & 0xff)
68 
69 int	db_output_position = 0;		/* output column */
70 int	db_output_line = 0;		/* output line number */
71 int	db_last_non_space = 0;		/* last non-space character */
72 int	db_tab_stop_width = 8;		/* how wide are tab stops? */
73 #define	NEXT_TAB(i) \
74 	((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
75 int	db_max_line = DB_MAX_LINE;	/* output max lines */
76 int	db_max_width = DB_MAX_WIDTH;	/* output line width */
77 
78 static void db_more __P((void));
79 
80 /*
81  * Force pending whitespace.
82  */
83 void
84 db_force_whitespace()
85 {
86 	register int last_print, next_tab;
87 
88 	last_print = db_last_non_space;
89 	while (last_print < db_output_position) {
90 	    next_tab = NEXT_TAB(last_print);
91 	    if (next_tab <= db_output_position) {
92 		while (last_print < next_tab) { /* DON'T send a tab!!! */
93 			cnputc(' ');
94 			last_print++;
95 		}
96 	    }
97 	    else {
98 		cnputc(' ');
99 		last_print++;
100 	    }
101 	}
102 	db_last_non_space = db_output_position;
103 }
104 
105 static void
106 db_more()
107 {
108 	register  char *p;
109 	int quit_output = 0;
110 
111 	for (p = "--db_more--"; *p; p++)
112 	    cnputc(*p);
113 	switch(cngetc()) {
114 	case ' ':
115 	    db_output_line = 0;
116 	    break;
117 	case 'q':
118 	case CTRL('c'):
119 	    db_output_line = 0;
120 	    quit_output = 1;
121 	    break;
122 	default:
123 	    db_output_line--;
124 	    break;
125 	}
126 	p = "\b\b\b\b\b\b\b\b\b\b\b           \b\b\b\b\b\b\b\b\b\b\b";
127 	while (*p)
128 	    cnputc(*p++);
129 	if (quit_output) {
130 	    db_error(0);
131 	    /* NOTREACHED */
132 	}
133 }
134 
135 /*
136  * Output character.  Buffer whitespace.
137  */
138 void
139 db_putchar(c)
140 	int	c;		/* character to output */
141 {
142 	if (db_max_line >= DB_MIN_MAX_LINE && db_output_line >= db_max_line-1)
143 	    db_more();
144 	if (c > ' ' && c <= '~') {
145 	    /*
146 	     * Printing character.
147 	     * If we have spaces to print, print them first.
148 	     * Use tabs if possible.
149 	     */
150 	    db_force_whitespace();
151 	    cnputc(c);
152 	    db_output_position++;
153 	    if (db_max_width >= DB_MIN_MAX_WIDTH
154 		&& db_output_position >= db_max_width-1) {
155 		/* auto new line */
156 		cnputc('\n');
157 		db_output_position = 0;
158 		db_last_non_space = 0;
159 		db_output_line++;
160 	    }
161 	    db_last_non_space = db_output_position;
162 	}
163 	else if (c == '\n') {
164 	    /* Return */
165 	    cnputc(c);
166 	    db_output_position = 0;
167 	    db_last_non_space = 0;
168 	    db_output_line++;
169 	    db_check_interrupt();
170 	}
171 	else if (c == '\t') {
172 	    /* assume tabs every 8 positions */
173 	    db_output_position = NEXT_TAB(db_output_position);
174 	}
175 	else if (c == ' ') {
176 	    /* space */
177 	    db_output_position++;
178 	}
179 	else if (c == '\007') {
180 	    /* bell */
181 	    cnputc(c);
182 	}
183 	/* other characters are assumed non-printing */
184 }
185 
186 /*
187  * Return output position
188  */
189 int
190 db_print_position()
191 {
192 	return (db_output_position);
193 }
194 
195 /*
196  * End line if too long.
197  */
198 void
199 db_end_line()
200 {
201 	if (db_output_position >= db_max_width)
202 	    db_printf("\n");
203 }
204