freebsd-src/sys/ddb/db_output.c
1996-01-23 21:17:59 +00:00

169 lines
3.8 KiB
C

/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: db_output.c,v 1.16 1996/01/15 22:39:35 phk Exp $
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
/*
* Printf and character output for debugger.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <machine/cons.h>
#include <machine/stdarg.h>
#include <ddb/ddb.h>
#include <ddb/db_output.h>
/*
* Character output - tracks position in line.
* To do this correctly, we should know how wide
* the output device is - then we could zero
* the line position when the output device wraps
* around to the start of the next line.
*
* Instead, we count the number of spaces printed
* since the last printing character so that we
* don't print trailing spaces. This avoids most
* of the wraparounds.
*/
static int db_output_position = 0; /* output column */
static int db_last_non_space = 0; /* last non-space character */
int db_tab_stop_width = 8; /* how wide are tab stops? */
#define NEXT_TAB(i) \
((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
int db_max_width = 80; /* output line width */
/*
* Force pending whitespace.
*/
void
db_force_whitespace()
{
register int last_print, next_tab;
last_print = db_last_non_space;
while (last_print < db_output_position) {
next_tab = NEXT_TAB(last_print);
if (next_tab <= db_output_position) {
while (last_print < next_tab) { /* DON'T send a tab!!! */
cnputc(' ');
last_print++;
}
}
else {
cnputc(' ');
last_print++;
}
}
db_last_non_space = db_output_position;
}
/*
* Output character. Buffer whitespace.
*/
void
db_putchar(c)
int c; /* character to output */
{
if (c > ' ' && c <= '~') {
/*
* Printing character.
* If we have spaces to print, print them first.
* Use tabs if possible.
*/
db_force_whitespace();
cnputc(c);
db_output_position++;
db_last_non_space = db_output_position;
}
else if (c == '\n') {
/* Newline */
cnputc(c);
db_output_position = 0;
db_last_non_space = 0;
db_check_interrupt();
}
else if (c == '\r') {
/* Return */
cnputc(c);
db_output_position = 0;
db_last_non_space = 0;
db_check_interrupt();
}
else if (c == '\t') {
/* assume tabs every 8 positions */
db_output_position = NEXT_TAB(db_output_position);
}
else if (c == ' ') {
/* space */
db_output_position++;
}
else if (c == '\007') {
/* bell */
cnputc(c);
}
/* other characters are assumed non-printing */
}
/*
* Return output position
*/
int
db_print_position()
{
return (db_output_position);
}
/*
* Printing
*/
void
db_printf(const char *fmt, ...)
{
va_list listp;
va_start(listp, fmt);
kvprintf (fmt, db_putchar, NULL, db_radix, listp);
va_end(listp);
}
/*
* End line if too long.
*/
void
db_end_line()
{
if (db_output_position >= db_max_width)
db_printf("\n");
}