1 /* $NetBSD: db_output.c,v 1.36 2020/01/26 01:42:55 uwe Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 */ 28 29 /* 30 * Printf and character output for debugger. 31 */ 32 33 #ifdef _KERNEL_OPT 34 #include "opt_ddbparam.h" 35 #endif 36 37 #include <sys/cdefs.h> 38 __KERNEL_RCSID(0, "$NetBSD: db_output.c,v 1.36 2020/01/26 01:42:55 uwe Exp $"); 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/stdarg.h> 43 44 #include <dev/cons.h> 45 46 #include <ddb/ddb.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 61 #ifndef DB_MAX_LINE 62 #define DB_MAX_LINE 24 /* maximum line */ 63 #endif /* DB_MAX_LINE */ 64 #ifndef DB_MAX_WIDTH 65 #define DB_MAX_WIDTH 80 /* maximum width */ 66 #endif /* DB_MAX_WIDTH */ 67 68 #define DB_MIN_MAX_WIDTH 20 /* minimum max width */ 69 #define DB_MIN_MAX_LINE 3 /* minimum max line */ 70 #define CTRL(c) ((c) & 0xff) 71 72 int db_output_line = 0; /* output line number */ 73 int db_tab_stop_width = 8; /* how wide are tab stops? */ 74 int db_max_line = DB_MAX_LINE; /* output max lines */ 75 int db_max_width = DB_MAX_WIDTH; /* output line width */ 76 77 static int db_output_position = 0; /* output column */ 78 static int db_last_non_space = 0; /* last non-space character */ 79 80 static void db_more(void); 81 82 /* 83 * Force pending whitespace. 84 */ 85 void 86 db_force_whitespace(void) 87 { 88 int last_print, next_tab; 89 90 last_print = db_last_non_space; 91 while (last_print < db_output_position) { 92 next_tab = DB_NEXT_TAB(last_print); 93 if (next_tab <= db_output_position) { 94 while (last_print < next_tab) { /* DON'T send a tab!! */ 95 cnputc(' '); 96 last_print++; 97 } 98 } else { 99 cnputc(' '); 100 last_print++; 101 } 102 } 103 db_last_non_space = db_output_position; 104 } 105 106 107 /* 108 * End the current line if it exceeds $maxwidth 109 */ 110 static void 111 db_check_wrap(void) 112 { 113 114 if (db_max_width >= DB_MIN_MAX_WIDTH 115 && db_output_position >= db_max_width) { 116 cnputc('\n'); 117 db_output_position = 0; 118 db_last_non_space = 0; 119 db_output_line++; 120 } 121 } 122 123 124 static void 125 db_more(void) 126 { 127 const char *p; 128 int quit_output = 0; 129 130 for (p = "--db_more--"; *p; p++) 131 cnputc(*p); 132 switch (cngetc()) { 133 case ' ': 134 db_output_line = 0; 135 break; 136 case 'q': 137 case CTRL('c'): 138 db_output_line = 0; 139 quit_output = 1; 140 break; 141 default: 142 db_output_line--; 143 break; 144 } 145 p = "\b\b\b\b\b\b\b\b\b\b\b \b\b\b\b\b\b\b\b\b\b\b"; 146 while (*p) 147 cnputc(*p++); 148 if (quit_output) { 149 db_error(0); 150 /* NOTREACHED */ 151 } 152 } 153 154 /* 155 * Output character. Buffer whitespace. 156 */ 157 void 158 db_putchar(int c) 159 { 160 if (db_max_line >= DB_MIN_MAX_LINE && db_output_line >= db_max_line-1) 161 db_more(); 162 if (c > ' ' && c <= '~') { 163 /* 164 * Printing character. 165 * If we have spaces to print, print them first. 166 * Use tabs if possible. 167 */ 168 db_force_whitespace(); 169 db_check_wrap(); 170 cnputc(c); 171 db_output_position++; 172 db_check_wrap(); 173 db_last_non_space = db_output_position; 174 } else if (c == '\n') { 175 /* Return */ 176 cnputc(c); 177 db_output_position = 0; 178 db_last_non_space = 0; 179 db_output_line++; 180 db_check_interrupt(); 181 } else if (c == '\t') { 182 /* assume tabs every 8 positions */ 183 db_output_position = DB_NEXT_TAB(db_output_position); 184 } else if (c == ' ') { 185 /* space */ 186 db_output_position++; 187 } else if (c == '\007') { 188 /* bell */ 189 cnputc(c); 190 } 191 /* other characters are assumed non-printing */ 192 } 193 194 /* 195 * Return output position 196 */ 197 int 198 db_print_position(void) 199 { 200 201 return (db_output_position); 202 } 203 204 /* 205 * End line if too long. 206 */ 207 void 208 db_end_line(void) 209 { 210 211 if (db_output_position >= db_max_width) 212 db_printf("\n"); 213 } 214 215 /* 216 * Replacement for old '%r' kprintf format. 217 */ 218 void 219 db_format_radix(char *buf, size_t bufsiz, quad_t val, int altflag) 220 { 221 const char *fmt; 222 223 if (db_radix == 16) { 224 db_format_hex(buf, bufsiz, val, altflag); 225 return; 226 } 227 228 if (db_radix == 8) 229 fmt = altflag ? "-%#qo" : "-%qo"; 230 else 231 fmt = altflag ? "-%#qu" : "-%qu"; 232 233 if (val < 0) 234 val = -val; 235 else 236 ++fmt; 237 238 snprintf(buf, bufsiz, fmt, val); 239 } 240 241 /* 242 * Replacement for old '%z' kprintf format. 243 */ 244 void 245 db_format_hex(char *buf, size_t bufsiz, quad_t val, int altflag) 246 { 247 /* Only use alternate form if val is nonzero. */ 248 const char *fmt = (altflag && val) ? "-%#qx" : "-%qx"; 249 250 if (val < 0) 251 val = -val; 252 else 253 ++fmt; 254 255 snprintf(buf, bufsiz, fmt, val); 256 } 257