1/* $NetBSD: db_input.c,v 1.26 2010/08/31 07:48:23 enami 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 * Author: David B. Golub, Carnegie Mellon University
29 * Date: 7/90
30 */
31
32#include <sys/cdefs.h>
33__KERNEL_RCSID(0, "$NetBSD: db_input.c,v 1.26 2010/08/31 07:48:23 enami Exp $");
34
35#ifdef _KERNEL_OPT
36#include "opt_ddbparam.h"
37#endif
38
39#include <sys/param.h>
40#include <sys/proc.h>
41#include <sys/cpu.h>
42
43#include <ddb/ddb.h>
44
45#include <dev/cons.h>
46
47#ifndef DDB_HISTORY_SIZE
48#define DDB_HISTORY_SIZE 0
49#endif /* DDB_HISTORY_SIZE */
50
51/*
52 * Character input and editing.
53 */
54
55/*
56 * We don't track output position while editing input,
57 * since input always ends with a new-line. We just
58 * reset the line position at the end.
59 */
60static char *db_lbuf_start; /* start of input line buffer */
61static char *db_lbuf_end; /* end of input line buffer */
62static char *db_lc; /* current character */
63static char *db_le; /* one past last character */
64#if DDB_HISTORY_SIZE != 0
65static char db_history[DDB_HISTORY_SIZE]; /* start of history buffer */
66static char *db_history_curr = db_history; /* start of current line */
67static char *db_history_last = db_history; /* start of last line */
68static char *db_history_prev = (char *) 0; /* start of previous line */
69#endif
70
71
72#define CTRL(c) ((c) & 0x1f)
73#define isspace(c) ((c) == ' ' || (c) == '\t')
74#define BLANK ' '
75#define BACKUP '\b'
76
77static int cnmaygetc(void);
78static void db_putstring(const char *, int);
79static void db_putnchars(int, int);
80static void db_delete(int, int);
81static void db_delete_line(void);
82static int db_inputchar(int);
83
84static void
85db_putstring(const char *s, int count)
86{
87
88 while (--count >= 0)
89 cnputc(*s++);
90}
91
92static void
93db_putnchars(int c, int count)
94{
95
96 while (--count >= 0)
97 cnputc(c);
98}
99
100/*
101 * Delete N characters, forward or backward
102 */
103#define DEL_FWD 0
104#define DEL_BWD 1
105static void
106db_delete(int n, int bwd)
107{
108 char *p;
109
110 if (bwd) {
111 db_lc -= n;
112 db_putnchars(BACKUP, n);
113 }
114 for (p = db_lc; p < db_le-n; p++) {
115 *p = *(p+n);
116 cnputc(*p);
117 }
118 db_putnchars(BLANK, n);
119 db_putnchars(BACKUP, db_le - db_lc);
120 db_le -= n;
121}
122
123static void
124db_delete_line(void)
125{
126
127 db_delete(db_le - db_lc, DEL_FWD);
128 db_delete(db_lc - db_lbuf_start, DEL_BWD);
129 db_le = db_lc = db_lbuf_start;
130}
131
132#if DDB_HISTORY_SIZE != 0
133
134#define INC_DB_CURR() do { \
135 ++db_history_curr; \
136 if (db_history_curr > db_history + DDB_HISTORY_SIZE - 1) \
137 db_history_curr = db_history; \
138 } while (0)
139#define DEC_DB_CURR() do { \
140 --db_history_curr; \
141 if (db_history_curr < db_history) \
142 db_history_curr = db_history + DDB_HISTORY_SIZE - 1; \
143 } while (0)
144
145static inline void
146db_hist_put(int c)
147{
148 KASSERT(&db_history[0] <= db_history_last);
149 KASSERT(db_history_last <= &db_history[DDB_HISTORY_SIZE-1]);
150
151 *db_history_last++ = c;
152
153 if (db_history_last > &db_history[DDB_HISTORY_SIZE-1])
154 db_history_last = db_history;
155}
156#endif
157
158
159/* returns true at end-of-line */
160static int
161db_inputchar(int c)
162{
163 switch (c) {
164 case CTRL('b'):
165 /* back up one character */
166 if (db_lc > db_lbuf_start) {
167 cnputc(BACKUP);
168 db_lc--;
169 }
170 break;
171 case CTRL('f'):
172 /* forward one character */
173 if (db_lc < db_le) {
174 cnputc(*db_lc);
175 db_lc++;
176 }
177 break;
178 case CTRL('a'):
179 /* beginning of line */
180 while (db_lc > db_lbuf_start) {
181 cnputc(BACKUP);
182 db_lc--;
183 }
184 break;
185 case CTRL('e'):
186 /* end of line */
187 while (db_lc < db_le) {
188 cnputc(*db_lc);
189 db_lc++;
190 }
191 break;
192 case CTRL('h'):
193 case 0177:
194 /* erase previous character */
195 if (db_lc > db_lbuf_start)
196 db_delete(1, DEL_BWD);
197 break;
198 case CTRL('d'):
199 /* erase next character */
200 if (db_lc < db_le)
201 db_delete(1, DEL_FWD);
202 break;
203 case CTRL('k'):
204 /* delete to end of line */
205 if (db_lc < db_le)
206 db_delete(db_le - db_lc, DEL_FWD);
207 break;
208 case CTRL('u'):
209 /* delete line */
210 db_delete_line();
211 break;
212 case CTRL('t'):
213 /* twiddle last 2 characters */
214 if (db_lc >= db_lbuf_start + 1) {
215 if (db_lc < db_le) {
216 c = db_lc[-1];
217 db_lc[-1] = db_lc[0];
218 db_lc[0] = c;
219 cnputc(BACKUP);
220 cnputc(db_lc[-1]);
221 cnputc(db_lc[0]);
222 db_lc++;
223 } else if (db_lc >= db_lbuf_start + 2) {
224 c = db_lc[-2];
225 db_lc[-2] = db_lc[-1];
226 db_lc[-1] = c;
227 cnputc(BACKUP);
228 cnputc(BACKUP);
229 cnputc(db_lc[-2]);
230 cnputc(db_lc[-1]);
231 }
232 }
233 break;
234#if DDB_HISTORY_SIZE != 0
235 case CTRL('p'):
236 DEC_DB_CURR();
237 while (db_history_curr != db_history_last) {
238 DEC_DB_CURR();
239 if (*db_history_curr == '\0')
240 break;
241 }
242 db_delete_line();
243 if (db_history_curr == db_history_last) {
244 INC_DB_CURR();
245 db_le = db_lc = db_lbuf_start;
246 } else {
247 char *p;
248 INC_DB_CURR();
249 for (p = db_history_curr, db_le = db_lbuf_start;
250 *p; ) {
251 *db_le++ = *p++;
252 if (p >= db_history + DDB_HISTORY_SIZE) {
253 p = db_history;
254 }
255 }
256 db_lc = db_le;
257 }
258 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
259 break;
260 case CTRL('n'):
261 while (db_history_curr != db_history_last) {
262 if (*db_history_curr == '\0')
263 break;
264 INC_DB_CURR();
265 }
266 if (db_history_curr != db_history_last) {
267 INC_DB_CURR();
268 db_delete_line();
269 if (db_history_curr != db_history_last) {
270 char *p;
271 for (p = db_history_curr,
272 db_le = db_lbuf_start; *p;) {
273 *db_le++ = *p++;
274 if (p >= db_history + DDB_HISTORY_SIZE) {
275 p = db_history;
276 }
277 }
278 db_lc = db_le;
279 }
280 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
281 }
282 break;
283#endif
284 case CTRL('r'):
285 db_putstring("^R\n", 3);
286 if (db_le > db_lbuf_start) {
287 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
288 db_putnchars(BACKUP, db_le - db_lc);
289 }
290 break;
291 case '\n':
292 case '\r':
293#if DDB_HISTORY_SIZE != 0
294 /* Check if it same than previous line */
295 if (db_history_curr == db_history_prev) {
296 char *pp, *pc;
297
298 /* Is it unmodified */
299 for (pp = db_history_prev, pc = db_lbuf_start;
300 pc != db_le && *pp; pp++, pc++) {
301 if (*pp != *pc)
302 break;
303 if (++pp >= db_history + DDB_HISTORY_SIZE) {
304 pp = db_history;
305 }
306 if (++pc >= db_history + DDB_HISTORY_SIZE) {
307 pc = db_history;
308 }
309 }
310 if (!*pp && pc == db_le) {
311 /* Repeted previous line, not saved */
312 db_history_curr = db_history_last;
313 *db_le++ = c;
314 return (true);
315 }
316 }
317 if (db_le != db_lbuf_start) {
318 char *p;
319
320 db_history_prev = db_history_last;
321
322 for (p = db_lbuf_start; p != db_le; ) {
323 db_hist_put(*p++);
324 }
325 db_hist_put(0);
326 }
327 db_history_curr = db_history_last;
328#endif
329 *db_le++ = c;
330 return (1);
331 default:
332 if (db_le == db_lbuf_end) {
333 cnputc('\007');
334 }
335 else if (c >= ' ' && c <= '~') {
336 char *p;
337
338 for (p = db_le; p > db_lc; p--)
339 *p = *(p-1);
340 *db_lc++ = c;
341 db_le++;
342 cnputc(c);
343 db_putstring(db_lc, db_le - db_lc);
344 db_putnchars(BACKUP, db_le - db_lc);
345 }
346 break;
347 }
348 return (0);
349}
350
351int
352db_readline(char *lstart, int lsize)
353{
354
355# ifdef MULTIPROCESSOR
356 db_printf("db{%ld}> ", (long)cpu_number());
357# else
358 db_printf("db> ");
359# endif
360 db_force_whitespace(); /* synch output position */
361
362 db_lbuf_start = lstart;
363 db_lbuf_end = lstart + lsize;
364 db_lc = lstart;
365 db_le = lstart;
366
367 while (!db_inputchar(cngetc()))
368 continue;
369
370 db_putchar('\n'); /* synch output position */
371
372 *db_le = 0;
373 return (db_le - db_lbuf_start);
374}
375
376void
377db_check_interrupt(void)
378{
379 int c;
380
381 c = cnmaygetc();
382 switch (c) {
383 case -1: /* no character */
384 return;
385
386 case CTRL('c'):
387 db_error((char *)0);
388 /*NOTREACHED*/
389
390 case CTRL('s'):
391 do {
392 c = cnmaygetc();
393 if (c == CTRL('c')) {
394 db_error((char *)0);
395 /*NOTREACHED*/
396 }
397 } while (c != CTRL('q'));
398 break;
399
400 default:
401 /* drop on floor */
402 break;
403 }
404}
405
406static int
407cnmaygetc(void)
408{
409
410 return (-1);
411}
412