sys/ddb/db_output.c

   1 /*
   2  * Mach Operating System
   3  * Copyright (c) 1991,1990 Carnegie Mellon University
   4  * All Rights Reserved.
   5  *
   6  * Permission to use, copy, modify and distribute this software and its
   7  * documentation is hereby granted, provided that both the copyright
   8  * notice and this permission notice appear in all copies of the
   9  * software, derivative works or modified versions, and any portions
  10  * thereof, and that both notices appear in supporting documentation.
  11  *
  12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
  13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  15  *
  16  * Carnegie Mellon requests users of this software to return to
  17  *
  18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  19  *  School of Computer Science
  20  *  Carnegie Mellon University
  21  *  Pittsburgh PA 15213-3890
  22  *
  23  * any improvements or extensions that they make and grant Carnegie the
  24  * rights to redistribute these changes.
  25  *
  26  * $FreeBSD: src/sys/ddb/db_output.c,v 1.26 1999/08/28 00:41:09 peter Exp $
  27  * $DragonFly: src/sys/ddb/db_output.c,v 1.8 2006/12/18 20:41:01 dillon Exp $
  28  */
  29
  30 /*
  31  *      Author: David B. Golub, Carnegie Mellon University
  32  *      Date:   7/90
  33  */
  34
  35 /*
  36  * Printf and character output for debugger.
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/systm.h>
  41 #include <sys/cons.h>
  42
  43 #include <machine/stdarg.h>
  44
  45 #include <ddb/ddb.h>
  46 #include <ddb/db_output.h>
  47
  48 /*
  49  *      Character output - tracks position in line.
  50  *      To do this correctly, we should know how wide
  51  *      the output device is - then we could zero
  52  *      the line position when the output device wraps
  53  *      around to the start of the next line.
  54  *
  55  *      Instead, we count the number of spaces printed
  56  *      since the last printing character so that we
  57  *      don't print trailing spaces.  This avoids most
  58  *      of the wraparounds.
  59  */
  60 static int      db_output_position = 0;         /* output column */
  61 static int      db_last_non_space = 0;          /* last non-space character */
  62 db_expr_t       db_tab_stop_width = 8;          /* how wide are tab stops? */
  63 #define NEXT_TAB(i) \
  64         ((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
  65 db_expr_t       db_max_width = 79;              /* output line width */
  66
  67 static void db_putchar (int c, void *arg);
  68
  69 /*
  70  * Force pending whitespace.
  71  */
  72 void
  73 db_force_whitespace(void)
  74 {
  75         int last_print, next_tab;
  76
  77         last_print = db_last_non_space;
  78         while (last_print < db_output_position) {
  79             next_tab = NEXT_TAB(last_print);
  80             if (next_tab <= db_output_position) {
  81                 while (last_print < next_tab) { /* DON'T send a tab!!! */
  82                         cnputc(' ');
  83                         last_print++;
  84                 }
  85             }
  86             else {
  87                 cnputc(' ');
  88                 last_print++;
  89             }
  90         }
  91         db_last_non_space = db_output_position;
  92 }
  93
  94 /*
  95  * Output character.  Buffer whitespace.
  96  *
  97  * Parameters:
  98  *     arg:     character to output
  99  */
 100 static void
 101 db_putchar(int c, void *arg)
 102 {
 103         if (c > ' ' && c <= '~') {
 104             /*
 105              * Printing character.
 106              * If we have spaces to print, print them first.
 107              * Use tabs if possible.
 108              */
 109             db_force_whitespace();
 110             cnputc(c);
 111             db_output_position++;
 112             db_last_non_space = db_output_position;
 113         }
 114         else if (c == '\n') {
 115             /* Newline */
 116             cnputc(c);
 117             db_output_position = 0;
 118             db_last_non_space = 0;
 119             db_check_interrupt();
 120         }
 121         else if (c == '\r') {
 122             /* Return */
 123             cnputc(c);
 124             db_output_position = 0;
 125             db_last_non_space = 0;
 126             db_check_interrupt();
 127         }
 128         else if (c == '\t') {
 129             /* assume tabs every 8 positions */
 130             db_output_position = NEXT_TAB(db_output_position);
 131         }
 132         else if (c == ' ') {
 133             /* space */
 134             db_output_position++;
 135         }
 136         else if (c == '\007') {
 137             /* bell */
 138             cnputc(c);
 139         }
 140         /* other characters are assumed non-printing */
 141 }
 142
 143 /*
 144  * Return output position
 145  */
 146 int
 147 db_print_position(void)
 148 {
 149         return (db_output_position);
 150 }
 151
 152 /*
 153  * Printing
 154  */
 155 void
 156 db_printf(const char *fmt, ...)
 157 {
 158         __va_list listp;
 159
 160         __va_start(listp, fmt);
 161         kvcprintf (fmt, db_putchar, NULL, db_radix, listp);
 162         __va_end(listp);
 163 }
 164
 165 int db_indent;
 166
 167 void
 168 db_iprintf(const char *fmt,...)
 169 {
 170         int i;
 171         __va_list listp;
 172
 173         for (i = db_indent; i >= 8; i -= 8)
 174                 db_printf("\t");
 175         while (--i >= 0)
 176                 db_printf(" ");
 177         __va_start(listp, fmt);
 178         kvcprintf (fmt, db_putchar, NULL, db_radix, listp);
 179         __va_end(listp);
 180 }
 181
 182 /*
 183  * End line if too long.
 184  */
 185 void
 186 db_end_line(void)
 187 {
 188         if (db_output_position >= db_max_width)
 189             db_printf("\n");
 190 }
 191
 192 /*
 193  * Simple pager
 194  */
 195 int
 196 db_more(int *nl)
 197 {
 198         ++*nl;
 199         if (*nl == 20) {
 200                 int c;
 201
 202                 db_printf("--More--");
 203                 c = cngetc();
 204                 db_printf("\r");
 205                 /*
 206                  * A whole screenfull or just one line?
 207                  */
 208                 switch (c) {
 209                 case '\n':              /* just one line */
 210                         *nl = 19;
 211                         break;
 212                 case ' ':
 213                         *nl = 0;        /* another screenfull */
 214                         break;
 215                 default:                /* exit */
 216                         db_printf("\n");
 217                         return(-1);
 218                 }
 219         }
 220         return(0);
 221 }
 222