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 } 222 223