freebsd-src/sys/ddb/db_output.c
Nate Lawson 5de6c5b5a5 If not in the debugger or if the user requests it with the
debug.ddb_use_printf sysctl, output kernel debugger data to both the
console and kernel message buffer via printf.  This fixes the case where
backtrace() went directly to the console and should help debugging greatly.
Thanks to Ian Dowse for the work, minor edits or any bugs are by myself.

Submitted by:	iedowse
2004-01-28 06:51:18 +00:00

291 lines
6.3 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.
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
/*
* Printf and character output for debugger.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cons.h>
#include <sys/kernel.h>
#include <sys/sysctl.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 */
db_expr_t 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)
db_expr_t db_max_width = 79; /* output line width */
static int db_newlines; /* # lines this page */
static int db_maxlines = -1; /* max lines per page */
static db_page_calloutfcn_t *db_page_callout = NULL;
static void *db_page_callout_arg = NULL;
static int ddb_use_printf = 0;
SYSCTL_INT(_debug, OID_AUTO, ddb_use_printf, CTLFLAG_RW, &ddb_use_printf, 0,
"use printf for all ddb output");
static void db_putchar(int c, void *arg);
/*
* 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.
*/
static void
db_putchar(c, arg)
int c; /* character to output */
void * arg;
{
/*
* If not in the debugger or the user requests it, output data to
* both the console and the message buffer.
*/
if (!db_active || ddb_use_printf) {
printf("%c", c);
if (!db_active)
return;
if (c == '\r' || c == '\n')
db_check_interrupt();
if (c == '\n' && db_maxlines > 0 && db_page_callout != NULL) {
db_newlines++;
if (db_newlines >= db_maxlines) {
db_maxlines = -1;
db_page_callout(db_page_callout_arg);
}
}
return;
}
/* Otherwise, output data directly to the console. */
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();
if (db_maxlines > 0 && db_page_callout != NULL) {
db_newlines++;
if (db_newlines >= db_maxlines) {
db_maxlines = -1;
db_page_callout(db_page_callout_arg);
}
}
}
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 */
}
/*
* Register callout for providing a pager for output.
*/
void
db_setup_paging(db_page_calloutfcn_t *callout, void *arg, int maxlines)
{
db_page_callout = callout;
db_page_callout_arg = arg;
db_maxlines = maxlines;
db_newlines = 0;
}
/*
* A simple paging callout function. If the argument is not null, it
* points to an integer that will be set to 1 if the user asks to quit.
*/
void
db_simple_pager(void *arg)
{
int c;
db_printf("--More--\r");
for (;;) {
c = cngetc();
switch (c) {
case '\n':
/* Just one more line. */
db_setup_paging(db_simple_pager, arg, 1);
return;
case ' ':
/* Another page. */
db_setup_paging(db_simple_pager, arg,
DB_LINES_PER_PAGE);
return;
case 'q':
case 'Q':
case 'x':
case 'X':
/* Quit */
if (arg != NULL) {
*(int *)arg = 1;
db_printf("\n");
return;
}
#if 0
/* FALLTHROUGH */
default:
cnputc('\007');
#endif
}
}
}
/*
* Return output position
*/
int
db_print_position()
{
return (db_output_position);
}
/*
* Printing
*/
void
#if __STDC__
db_printf(const char *fmt, ...)
#else
db_printf(fmt)
const char *fmt;
#endif
{
va_list listp;
va_start(listp, fmt);
kvprintf (fmt, db_putchar, NULL, db_radix, listp);
va_end(listp);
}
int db_indent;
void
#if __STDC__
db_iprintf(const char *fmt,...)
#else
db_iprintf(fmt)
const char *fmt;
#endif
{
register int i;
va_list listp;
for (i = db_indent; i >= 8; i -= 8)
db_printf("\t");
while (--i >= 0)
db_printf(" ");
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");
}