/*      $NetBSD: db_output.c,v 1.38 2023/10/07 20:22:53 ad Exp $        */

/*
 * 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 "AS IS"
 * 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.
 */

/*
 * Printf and character output for debugger.
 */

#ifdef _KERNEL_OPT
#include "opt_ddbparam.h"
#endif

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_output.c,v 1.38 2023/10/07 20:22:53 ad Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/stdarg.h>
#include <sys/time.h>

#include <dev/cons.h>

#include <ddb/ddb.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.
 */

#ifndef DB_MAX_LINE
#define DB_MAX_LINE             24      /* maximum line */
#endif  /* DB_MAX_LINE */
#ifndef DB_MAX_WIDTH
#define DB_MAX_WIDTH            80      /* maximum width */
#endif  /* DB_MAX_WIDTH */

#define DB_MIN_MAX_WIDTH        20      /* minimum max width */
#define DB_MIN_MAX_LINE         3       /* minimum max line */
#define CTRL(c)                 ((c) & 0xff)

int     db_output_line = 0;                     /* output line number */
int     db_tab_stop_width = 8;                  /* how wide are tab stops? */
int     db_max_line = DB_MAX_LINE;              /* output max lines */
int     db_max_width = DB_MAX_WIDTH;            /* output line width */

static int      db_output_position = 0;         /* output column */
static int      db_last_non_space = 0;          /* last non-space character */

static void db_more(void);

/*
 * Force pending whitespace.
 */
void
db_force_whitespace(void)
{
        int last_print, next_tab;

        last_print = db_last_non_space;
        while (last_print < db_output_position) {
                next_tab = DB_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;
}


/*
 * End the current line if it exceeds $maxwidth
 */
static void
db_check_wrap(void)
{

        if (db_max_width >= DB_MIN_MAX_WIDTH
            && db_output_position >= db_max_width) {
                cnputc('\n');
                db_output_position = 0;
                db_last_non_space = 0;
                db_output_line++;
        }
}


static void
db_more(void)
{
        const char *p;
        int quit_output = 0;

        for (p = "--db_more--"; *p; p++)
                cnputc(*p);
        switch (cngetc()) {
        case ' ':
                db_output_line = 0;
                break;
        case 'q':
        case CTRL('c'):
                db_output_line = 0;
                quit_output = 1;
                break;
        default:
                db_output_line--;
                break;
        }
        p = "\b\b\b\b\b\b\b\b\b\b\b           \b\b\b\b\b\b\b\b\b\b\b";
        while (*p)
                cnputc(*p++);
        if (quit_output) {
                db_error(0);
                /* NOTREACHED */
        }
}

/*
 * Output character.  Buffer whitespace.
 */
void
db_putchar(int c)
{
        if (db_max_line >= DB_MIN_MAX_LINE && db_output_line >= db_max_line-1)
                db_more();
        if (c > ' ' && c <= '~') {
                /*
                 * Printing character.
                 * If we have spaces to print, print them first.
                 * Use tabs if possible.
                 */
                db_force_whitespace();
                db_check_wrap();
                cnputc(c);
                db_output_position++;
                db_check_wrap();
                db_last_non_space = db_output_position;
        } else if (c == '\n') {
                /* Return */
                cnputc(c);
                db_output_position = 0;
                db_last_non_space = 0;
                db_output_line++;
                db_check_interrupt();
        } else if (c == '\t') {
                /* assume tabs every 8 positions */
                db_output_position = DB_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(void)
{

        return (db_output_position);
}

/*
 * End line if too long.
 */
void
db_end_line(void)
{

        if (db_output_position >= db_max_width)
                db_printf("\n");
}

/*
 * Replacement for old '%r' kprintf format.
 */
void
db_format_radix(char *buf, size_t bufsiz, quad_t val, int altflag)
{
        const char *fmt;

        if (db_radix == 16) {
                db_format_hex(buf, bufsiz, val, altflag);
                return;
        }

        if (db_radix == 8)
                fmt = altflag ? "-%#qo" : "-%qo";
        else
                fmt = altflag ? "-%#qu" : "-%qu";

        if (val < 0)
                val = -val;
        else
                ++fmt;

        snprintf(buf, bufsiz, fmt, val);
}

/*
 * Replacement for old '%z' kprintf format.
 */
void
db_format_hex(char *buf, size_t bufsiz, quad_t val, int altflag)
{
        /* Only use alternate form if val is nonzero. */
        const char *fmt = (altflag && val) ? "-%#qx" : "-%qx";

        if (val < 0)
                val = -val;
        else
                ++fmt;

        snprintf(buf, bufsiz, fmt, val);
}

/*
 * Print out a timespec value.
 */
void
db_print_timespec(struct timespec *ts)
{

        db_printf("%" PRIu64 ".%09ld", (uint64_t)ts->tv_sec, ts->tv_nsec);
}