db_input.c revision 1.17 
1/*	$NetBSD: db_input.c,v 1.17 2002/02/15 07:33:51 simonb 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 1.17 2002/02/15 07:33:51 simonb Exp $");
34
35#include "opt_ddb.h"
36
37#include <sys/param.h>
38#include <sys/proc.h>
39
40#include <machine/db_machdep.h>
41
42#include <ddb/db_output.h>
43#include <ddb/db_command.h>
44#include <ddb/db_sym.h>
45#include <ddb/db_extern.h>
46
47#include <dev/cons.h>
48
49#ifndef DDB_HISTORY_SIZE
50#define DDB_HISTORY_SIZE 0
51#endif /* DDB_HISTORY_SIZE */
52
53/*
54 * Character input and editing.
55 */
56
57/*
58 * We don't track output position while editing input,
59 * since input always ends with a new-line.  We just
60 * reset the line position at the end.
61 */
62static char    *db_lbuf_start;	/* start of input line buffer */
63static char    *db_lbuf_end;	/* end of input line buffer */
64static char    *db_lc;		/* current character */
65static char    *db_le;		/* one past last character */
66#if DDB_HISTORY_SIZE != 0
67static char	db_history[DDB_HISTORY_SIZE];	/* start of history buffer */
68static int	db_history_size = DDB_HISTORY_SIZE;/* size of history buffer */
69static char    *db_history_curr = db_history;	/* start of current line */
70static char    *db_history_last = db_history;	/* start of last line */
71static char    *db_history_prev = (char *) 0;	/* start of previous line */
72#endif
73
74
75#define	CTRL(c)		((c) & 0x1f)
76#define	isspace(c)	((c) == ' ' || (c) == '\t')
77#define	BLANK		' '
78#define	BACKUP		'\b'
79
80static int	cnmaygetc(void);
81static void	db_putstring(char *, int);
82static void	db_putnchars(int, int);
83static void	db_delete(int, int);
84static void	db_delete_line(void);
85static int	db_inputchar(int);
86
87static void
88db_putstring(char *s, int count)
89{
90
91	while (--count >= 0)
92		cnputc(*s++);
93}
94
95static void
96db_putnchars(int c, int count)
97{
98
99	while (--count >= 0)
100		cnputc(c);
101}
102
103/*
104 * Delete N characters, forward or backward
105 */
106#define	DEL_FWD		0
107#define	DEL_BWD		1
108static void
109db_delete(int n, int bwd)
110{
111	char *p;
112
113	if (bwd) {
114		db_lc -= n;
115		db_putnchars(BACKUP, n);
116	}
117	for (p = db_lc; p < db_le-n; p++) {
118		*p = *(p+n);
119		cnputc(*p);
120	}
121	db_putnchars(BLANK, n);
122	db_putnchars(BACKUP, db_le - db_lc);
123	db_le -= n;
124}
125
126static void
127db_delete_line(void)
128{
129
130	db_delete(db_le - db_lc, DEL_FWD);
131	db_delete(db_lc - db_lbuf_start, DEL_BWD);
132	db_le = db_lc = db_lbuf_start;
133}
134
135#if DDB_HISTORY_SIZE != 0
136#define INC_DB_CURR() \
137	do { \
138		 db_history_curr++; \
139		 if (db_history_curr > db_history + db_history_size - 1) \
140			 db_history_curr = db_history; \
141	} while (0)
142#define DEC_DB_CURR() \
143	do { \
144		 db_history_curr--; \
145		 if (db_history_curr < db_history) \
146		     db_history_curr = db_history + \
147		     db_history_size - 1; \
148	} while (0)
149#endif
150
151/* returns TRUE at end-of-line */
152static int
153db_inputchar(int c)
154{
155	switch (c) {
156	case CTRL('b'):
157		/* back up one character */
158		if (db_lc > db_lbuf_start) {
159			cnputc(BACKUP);
160			db_lc--;
161		}
162		break;
163	case CTRL('f'):
164		/* forward one character */
165		if (db_lc < db_le) {
166			cnputc(*db_lc);
167			db_lc++;
168		}
169		break;
170	case CTRL('a'):
171		/* beginning of line */
172		while (db_lc > db_lbuf_start) {
173			cnputc(BACKUP);
174			db_lc--;
175		}
176		break;
177	case CTRL('e'):
178		/* end of line */
179		while (db_lc < db_le) {
180			cnputc(*db_lc);
181			db_lc++;
182		}
183		break;
184	case CTRL('h'):
185	case 0177:
186		/* erase previous character */
187		if (db_lc > db_lbuf_start)
188			db_delete(1, DEL_BWD);
189		break;
190	case CTRL('d'):
191		/* erase next character */
192		if (db_lc < db_le)
193			db_delete(1, DEL_FWD);
194		break;
195	case CTRL('k'):
196		/* delete to end of line */
197		if (db_lc < db_le)
198			db_delete(db_le - db_lc, DEL_FWD);
199		break;
200	case CTRL('u'):
201		/* delete line */
202		db_delete_line();
203		break;
204	case CTRL('t'):
205		/* twiddle last 2 characters */
206		if (db_lc >= db_lbuf_start + 1) {
207			if (db_lc < db_le) {
208				c = db_lc[-1];
209				db_lc[-1] = db_lc[0];
210				db_lc[0] = c;
211				cnputc(BACKUP);
212				cnputc(db_lc[-1]);
213				cnputc(db_lc[0]);
214				db_lc++;
215			} else if (db_lc >= db_lbuf_start + 2) {
216				c = db_lc[-2];
217				db_lc[-2] = db_lc[-1];
218				db_lc[-1] = c;
219				cnputc(BACKUP);
220				cnputc(BACKUP);
221				cnputc(db_lc[-2]);
222				cnputc(db_lc[-1]);
223			}
224		}
225		break;
226#if DDB_HISTORY_SIZE != 0
227	case CTRL('p'):
228		DEC_DB_CURR();
229		while (db_history_curr != db_history_last) {
230			DEC_DB_CURR();
231			if (*db_history_curr == '\0')
232				break;
233		}
234		db_delete_line();
235		if (db_history_curr == db_history_last) {
236			INC_DB_CURR();
237			db_le = db_lc = db_lbuf_start;
238		} else {
239			char *p;
240			INC_DB_CURR();
241			for (p = db_history_curr, db_le = db_lbuf_start;
242			     *p; ) {
243				*db_le++ = *p++;
244				if (p == db_history + db_history_size) {
245					p = db_history;
246				}
247			}
248			db_lc = db_le;
249		}
250		db_putstring(db_lbuf_start, db_le - db_lbuf_start);
251		break;
252	case CTRL('n'):
253		while (db_history_curr != db_history_last) {
254			if (*db_history_curr == '\0')
255				break;
256			INC_DB_CURR();
257		}
258		if (db_history_curr != db_history_last) {
259			INC_DB_CURR();
260			db_delete_line();
261			if (db_history_curr != db_history_last) {
262				char *p;
263				for (p = db_history_curr,
264				     db_le = db_lbuf_start; *p;) {
265					*db_le++ = *p++;
266					if (p == db_history +
267					    db_history_size) {
268						p = db_history;
269					}
270				}
271				db_lc = db_le;
272			}
273			db_putstring(db_lbuf_start, db_le - db_lbuf_start);
274		}
275		break;
276#endif
277	case CTRL('r'):
278		db_putstring("^R\n", 3);
279		if (db_le > db_lbuf_start) {
280			db_putstring(db_lbuf_start, db_le - db_lbuf_start);
281			db_putnchars(BACKUP, db_le - db_lc);
282		}
283		break;
284	case '\n':
285	case '\r':
286#if DDB_HISTORY_SIZE != 0
287		/* Check if it same than previous line */
288		if (db_history_curr == db_history_prev) {
289			char *pp, *pc;
290
291			/* Is it unmodified */
292			for (pp = db_history_prev, pc = db_lbuf_start;
293			     pc != db_le && *pp; pp++, pc++) {
294				if (*pp != *pc)
295					break;
296				if (++pp == db_history + db_history_size) {
297					pp = db_history;
298				}
299				if (++pc == db_history + db_history_size) {
300					pc = db_history;
301				}
302			}
303			if (!*pp && pc == db_le) {
304				/* Repeted previous line, not saved */
305				db_history_curr = db_history_last;
306				*db_le++ = c;
307				return (TRUE);
308			}
309		}
310		if (db_le != db_lbuf_start) {
311			char *p;
312			db_history_prev = db_history_last;
313			for (p = db_lbuf_start; p != db_le; p++) {
314				*db_history_last++ = *p;
315				if (db_history_last == db_history +
316				    db_history_size) {
317					db_history_last = db_history;
318				}
319			}
320			*db_history_last++ = '\0';
321		}
322		db_history_curr = db_history_last;
323#endif
324		*db_le++ = c;
325		return (1);
326	default:
327		if (db_le == db_lbuf_end) {
328			cnputc('\007');
329		}
330		else if (c >= ' ' && c <= '~') {
331			char *p;
332
333			for (p = db_le; p > db_lc; p--)
334				*p = *(p-1);
335			*db_lc++ = c;
336			db_le++;
337			cnputc(c);
338			db_putstring(db_lc, db_le - db_lc);
339			db_putnchars(BACKUP, db_le - db_lc);
340		}
341		break;
342	}
343	return (0);
344}
345
346int
347db_readline(char *lstart, int lsize)
348{
349	db_force_whitespace();	/* synch output position */
350
351	db_lbuf_start = lstart;
352	db_lbuf_end   = lstart + lsize;
353	db_lc = lstart;
354	db_le = lstart;
355
356	while (!db_inputchar(cngetc()))
357		continue;
358
359	db_putchar('\n');	/* synch output position */
360
361	*db_le = 0;
362	return (db_le - db_lbuf_start);
363}
364
365void
366db_check_interrupt(void)
367{
368	int	c;
369
370	c = cnmaygetc();
371	switch (c) {
372	case -1:		/* no character */
373		return;
374
375	case CTRL('c'):
376		db_error((char *)0);
377		/*NOTREACHED*/
378
379	case CTRL('s'):
380		do {
381			c = cnmaygetc();
382			if (c == CTRL('c')) {
383				db_error((char *)0);
384				/*NOTREACHED*/
385			}
386		} while (c != CTRL('q'));
387		break;
388
389	default:
390		/* drop on floor */
391		break;
392	}
393}
394
395static int
396cnmaygetc(void)
397{
398
399	return (-1);
400}
401