xref: /freebsd/contrib/nvi/ex/ex_cscope.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*-
2  * Copyright (c) 1994, 1996
3  *	Rob Mayoff.  All rights reserved.
4  * Copyright (c) 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "@(#)ex_cscope.c	10.13 (Berkeley) 9/15/96";
14 #endif /* not lint */
15 
16 #include <sys/param.h>
17 #include <sys/types.h>		/* XXX: param.h may not have included types.h */
18 #include <sys/queue.h>
19 #include <sys/stat.h>
20 #include <sys/time.h>
21 #include <sys/wait.h>
22 
23 #include <bitstring.h>
24 #include <ctype.h>
25 #include <errno.h>
26 #include <fcntl.h>
27 #include <limits.h>
28 #include <stddef.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <termios.h>
33 #include <unistd.h>
34 
35 #include "../common/common.h"
36 #include "pathnames.h"
37 #include "tag.h"
38 
39 #define	CSCOPE_DBFILE		"cscope.out"
40 #define	CSCOPE_PATHS		"cscope.tpath"
41 
42 /*
43  * 0name	find all uses of name
44  * 1name	find definition of name
45  * 2name	find all function calls made from name
46  * 3name	find callers of name
47  * 4string	find text string (cscope 12.9)
48  * 4name	find assignments to name (cscope 13.3)
49  * 5pattern	change pattern -- NOT USED
50  * 6pattern	find pattern
51  * 7name	find files with name as substring
52  * 8name	find files #including name
53  */
54 #define	FINDHELP "\
55 find c|d|e|f|g|i|s|t buffer|pattern\n\
56       c: find callers of name\n\
57       d: find all function calls made from name\n\
58       e: find pattern\n\
59       f: find files with name as substring\n\
60       g: find definition of name\n\
61       i: find files #including name\n\
62       s: find all uses of name\n\
63       t: find assignments to name"
64 
65 static int cscope_add __P((SCR *, EXCMD *, char *));
66 static int cscope_find __P((SCR *, EXCMD*, char *));
67 static int cscope_help __P((SCR *, EXCMD *, char *));
68 static int cscope_kill __P((SCR *, EXCMD *, char *));
69 static int cscope_reset __P((SCR *, EXCMD *, char *));
70 
71 typedef struct _cc {
72 	char	 *name;
73 	int	(*function) __P((SCR *, EXCMD *, char *));
74 	char	 *help_msg;
75 	char	 *usage_msg;
76 } CC;
77 
78 static CC const cscope_cmds[] = {
79 	{ "add",   cscope_add,
80 	  "Add a new cscope database", "add file | directory" },
81 	{ "find",  cscope_find,
82 	  "Query the databases for a pattern", FINDHELP },
83 	{ "help",  cscope_help,
84 	  "Show help for cscope commands", "help [command]" },
85 	{ "kill",  cscope_kill,
86 	  "Kill a cscope connection", "kill number" },
87 	{ "reset", cscope_reset,
88 	  "Discard all current cscope connections", "reset" },
89 	{ NULL }
90 };
91 
92 static TAGQ	*create_cs_cmd __P((SCR *, char *, size_t *));
93 static int	 csc_help __P((SCR *, char *));
94 static void	 csc_file __P((SCR *,
95 		    CSC *, char *, char **, size_t *, int *));
96 static int	 get_paths __P((SCR *, CSC *));
97 static CC const	*lookup_ccmd __P((char *));
98 static int	 parse __P((SCR *, CSC *, TAGQ *, int *));
99 static int	 read_prompt __P((SCR *, CSC *));
100 static int	 run_cscope __P((SCR *, CSC *, char *));
101 static int	 start_cscopes __P((SCR *, EXCMD *));
102 static int	 terminate __P((SCR *, CSC *, int));
103 
104 /*
105  * ex_cscope --
106  *	Perform an ex cscope.
107  *
108  * PUBLIC: int ex_cscope __P((SCR *, EXCMD *));
109  */
110 int
111 ex_cscope(sp, cmdp)
112 	SCR *sp;
113 	EXCMD *cmdp;
114 {
115 	CC const *ccp;
116 	EX_PRIVATE *exp;
117 	int i;
118 	char *cmd, *p;
119 
120 	/* Initialize the default cscope directories. */
121 	exp = EXP(sp);
122 	if (!F_ISSET(exp, EXP_CSCINIT) && start_cscopes(sp, cmdp))
123 		return (1);
124 	F_SET(exp, EXP_CSCINIT);
125 
126 	/* Skip leading whitespace. */
127 	for (p = cmdp->argv[0]->bp, i = cmdp->argv[0]->len; i > 0; --i, ++p)
128 		if (!isspace(*p))
129 			break;
130 	if (i == 0)
131 		goto usage;
132 
133 	/* Skip the command to any arguments. */
134 	for (cmd = p; i > 0; --i, ++p)
135 		if (isspace(*p))
136 			break;
137 	if (*p != '\0') {
138 		*p++ = '\0';
139 		for (; *p && isspace(*p); ++p);
140 	}
141 
142 	if ((ccp = lookup_ccmd(cmd)) == NULL) {
143 usage:		msgq(sp, M_ERR, "309|Use \"cscope help\" for help");
144 		return (1);
145 	}
146 
147 	/* Call the underlying function. */
148 	return (ccp->function(sp, cmdp, p));
149 }
150 
151 /*
152  * start_cscopes --
153  *	Initialize the cscope package.
154  */
155 static int
156 start_cscopes(sp, cmdp)
157 	SCR *sp;
158 	EXCMD *cmdp;
159 {
160 	size_t blen, len;
161 	char *bp, *cscopes, *p, *t;
162 
163 	/*
164 	 * EXTENSION #1:
165 	 *
166 	 * If the CSCOPE_DIRS environment variable is set, we treat it as a
167 	 * list of cscope directories that we're using, similar to the tags
168 	 * edit option.
169 	 *
170 	 * XXX
171 	 * This should probably be an edit option, although that implies that
172 	 * we start/stop cscope processes periodically, instead of once when
173 	 * the editor starts.
174 	 */
175 	if ((cscopes = getenv("CSCOPE_DIRS")) == NULL)
176 		return (0);
177 	len = strlen(cscopes);
178 	GET_SPACE_RET(sp, bp, blen, len);
179 	memcpy(bp, cscopes, len + 1);
180 
181 	for (cscopes = t = bp; (p = strsep(&t, "\t :")) != NULL;)
182 		if (*p != '\0')
183 			(void)cscope_add(sp, cmdp, p);
184 
185 	FREE_SPACE(sp, bp, blen);
186 	return (0);
187 }
188 
189 /*
190  * cscope_add --
191  *	The cscope add command.
192  */
193 static int
194 cscope_add(sp, cmdp, dname)
195 	SCR *sp;
196 	EXCMD *cmdp;
197 	char *dname;
198 {
199 	struct stat sb;
200 	EX_PRIVATE *exp;
201 	CSC *csc;
202 	size_t len;
203 	int cur_argc;
204 	char *dbname, path[MAXPATHLEN];
205 
206 	exp = EXP(sp);
207 
208 	/*
209 	 *  0 additional args: usage.
210 	 *  1 additional args: matched a file.
211 	 * >1 additional args: object, too many args.
212 	 */
213 	cur_argc = cmdp->argc;
214 	if (argv_exp2(sp, cmdp, dname, strlen(dname)))
215 		return (1);
216 	if (cmdp->argc == cur_argc) {
217 		(void)csc_help(sp, "add");
218 		return (1);
219 	}
220 	if (cmdp->argc == cur_argc + 1)
221 		dname = cmdp->argv[cur_argc]->bp;
222 	else {
223 		ex_emsg(sp, dname, EXM_FILECOUNT);
224 		return (1);
225 	}
226 
227 	/*
228 	 * The user can specify a specific file (so they can have multiple
229 	 * Cscope databases in a single directory) or a directory.  If the
230 	 * file doesn't exist, we're done.  If it's a directory, append the
231 	 * standard database file name and try again.  Store the directory
232 	 * name regardless so that we can use it as a base for searches.
233 	 */
234 	if (stat(dname, &sb)) {
235 		msgq(sp, M_SYSERR, dname);
236 		return (1);
237 	}
238 	if (S_ISDIR(sb.st_mode)) {
239 		(void)snprintf(path, sizeof(path),
240 		    "%s/%s", dname, CSCOPE_DBFILE);
241 		if (stat(path, &sb)) {
242 			msgq(sp, M_SYSERR, path);
243 			return (1);
244 		}
245 		dbname = CSCOPE_DBFILE;
246 	} else if ((dbname = strrchr(dname, '/')) != NULL)
247 		*dbname++ = '\0';
248 
249 	/* Allocate a cscope connection structure and initialize its fields. */
250 	len = strlen(dname);
251 	CALLOC_RET(sp, csc, CSC *, 1, sizeof(CSC) + len);
252 	csc->dname = csc->buf;
253 	csc->dlen = len;
254 	memcpy(csc->dname, dname, len);
255 	csc->mtime = sb.st_mtime;
256 
257 	/* Get the search paths for the cscope. */
258 	if (get_paths(sp, csc))
259 		goto err;
260 
261 	/* Start the cscope process. */
262 	if (run_cscope(sp, csc, dbname))
263 		goto err;
264 
265 	/*
266 	 * Add the cscope connection to the screen's list.  From now on,
267 	 * on error, we have to call terminate, which expects the csc to
268 	 * be on the chain.
269 	 */
270 	LIST_INSERT_HEAD(&exp->cscq, csc, q);
271 
272 	/* Read the initial prompt from the cscope to make sure it's okay. */
273 	if (read_prompt(sp, csc)) {
274 		terminate(sp, csc, 0);
275 		return (1);
276 	}
277 
278 	return (0);
279 
280 err:	free(csc);
281 	return (1);
282 }
283 
284 /*
285  * get_paths --
286  *	Get the directories to search for the files associated with this
287  *	cscope database.
288  */
289 static int
290 get_paths(sp, csc)
291 	SCR *sp;
292 	CSC *csc;
293 {
294 	struct stat sb;
295 	int fd, nentries;
296 	size_t len;
297 	char *p, **pathp, buf[MAXPATHLEN * 2];
298 
299 	/*
300 	 * EXTENSION #2:
301 	 *
302 	 * If there's a cscope directory with a file named CSCOPE_PATHS, it
303 	 * contains a colon-separated list of paths in which to search for
304 	 * files returned by cscope.
305 	 *
306 	 * XXX
307 	 * These paths are absolute paths, and not relative to the cscope
308 	 * directory.  To fix this, rewrite the each path using the cscope
309 	 * directory as a prefix.
310 	 */
311 	(void)snprintf(buf, sizeof(buf), "%s/%s", csc->dname, CSCOPE_PATHS);
312 	if (stat(buf, &sb) == 0) {
313 		/* Read in the CSCOPE_PATHS file. */
314 		len = sb.st_size;
315 		MALLOC_RET(sp, csc->pbuf, char *, len + 1);
316 		if ((fd = open(buf, O_RDONLY, 0)) < 0 ||
317 		    read(fd, csc->pbuf, len) != len) {
318 			 msgq_str(sp, M_SYSERR, buf, "%s");
319 			 if (fd >= 0)
320 				(void)close(fd);
321 			 return (1);
322 		}
323 		(void)close(fd);
324 		csc->pbuf[len] = '\0';
325 
326 		/* Count up the entries. */
327 		for (nentries = 0, p = csc->pbuf; *p != '\0'; ++p)
328 			if (p[0] == ':' && p[1] != '\0')
329 				++nentries;
330 
331 		/* Build an array of pointers to the paths. */
332 		CALLOC_GOTO(sp,
333 		    csc->paths, char **, nentries + 1, sizeof(char **));
334 		for (pathp = csc->paths, p = strtok(csc->pbuf, ":");
335 		    p != NULL; p = strtok(NULL, ":"))
336 			*pathp++ = p;
337 		return (0);
338 	}
339 
340 	/*
341 	 * If the CSCOPE_PATHS file doesn't exist, we look for files
342 	 * relative to the cscope directory.
343 	 */
344 	if ((csc->pbuf = strdup(csc->dname)) == NULL) {
345 		msgq(sp, M_SYSERR, NULL);
346 		return (1);
347 	}
348 	CALLOC_GOTO(sp, csc->paths, char **, 2, sizeof(char *));
349 	csc->paths[0] = csc->pbuf;
350 	return (0);
351 
352 alloc_err:
353 	if (csc->pbuf != NULL) {
354 		free(csc->pbuf);
355 		csc->pbuf = NULL;
356 	}
357 	return (1);
358 }
359 
360 /*
361  * run_cscope --
362  *	Fork off the cscope process.
363  */
364 static int
365 run_cscope(sp, csc, dbname)
366 	SCR *sp;
367 	CSC *csc;
368 	char *dbname;
369 {
370 	int to_cs[2], from_cs[2];
371 	char cmd[MAXPATHLEN * 2];
372 
373 	/*
374 	 * Cscope reads from to_cs[0] and writes to from_cs[1]; vi reads from
375 	 * from_cs[0] and writes to to_cs[1].
376 	 */
377 	to_cs[0] = to_cs[1] = from_cs[0] = from_cs[0] = -1;
378 	if (pipe(to_cs) < 0 || pipe(from_cs) < 0) {
379 		msgq(sp, M_SYSERR, "pipe");
380 		goto err;
381 	}
382 	switch (csc->pid = vfork()) {
383 	case -1:
384 		msgq(sp, M_SYSERR, "vfork");
385 err:		if (to_cs[0] != -1)
386 			(void)close(to_cs[0]);
387 		if (to_cs[1] != -1)
388 			(void)close(to_cs[1]);
389 		if (from_cs[0] != -1)
390 			(void)close(from_cs[0]);
391 		if (from_cs[1] != -1)
392 			(void)close(from_cs[1]);
393 		return (1);
394 	case 0:				/* child: run cscope. */
395 		(void)dup2(to_cs[0], STDIN_FILENO);
396 		(void)dup2(from_cs[1], STDOUT_FILENO);
397 		(void)dup2(from_cs[1], STDERR_FILENO);
398 
399 		/* Close unused file descriptors. */
400 		(void)close(to_cs[1]);
401 		(void)close(from_cs[0]);
402 
403 		/* Run the cscope command. */
404 #define	CSCOPE_CMD_FMT		"cd '%s' && exec cscope -dl -f %s"
405 		(void)snprintf(cmd, sizeof(cmd),
406 		    CSCOPE_CMD_FMT, csc->dname, dbname);
407 		(void)execl(_PATH_BSHELL, "sh", "-c", cmd, NULL);
408 		msgq_str(sp, M_SYSERR, cmd, "execl: %s");
409 		_exit (127);
410 		/* NOTREACHED */
411 	default:			/* parent. */
412 		/* Close unused file descriptors. */
413 		(void)close(to_cs[0]);
414 		(void)close(from_cs[1]);
415 
416 		/*
417 		 * Save the file descriptors for later duplication, and
418 		 * reopen as streams.
419 		 */
420 		csc->to_fd = to_cs[1];
421 		csc->to_fp = fdopen(to_cs[1], "w");
422 		csc->from_fd = from_cs[0];
423 		csc->from_fp = fdopen(from_cs[0], "r");
424 		break;
425 	}
426 	return (0);
427 }
428 
429 /*
430  * cscope_find --
431  *	The cscope find command.
432  */
433 static int
434 cscope_find(sp, cmdp, pattern)
435 	SCR *sp;
436 	EXCMD *cmdp;
437 	char *pattern;
438 {
439 	CSC *csc, *csc_next;
440 	EX_PRIVATE *exp;
441 	FREF *frp;
442 	TAGQ *rtqp, *tqp;
443 	TAG *rtp;
444 	recno_t lno;
445 	size_t cno, search;
446 	int force, istmp, matches;
447 
448 	exp = EXP(sp);
449 
450 	/* Check for connections. */
451 	if (exp->cscq.lh_first == NULL) {
452 		msgq(sp, M_ERR, "310|No cscope connections running");
453 		return (1);
454 	}
455 
456 	/*
457 	 * Allocate all necessary memory before doing anything hard.  If the
458 	 * tags stack is empty, we'll need the `local context' TAGQ structure
459 	 * later.
460 	 */
461 	rtp = NULL;
462 	rtqp = NULL;
463 	if (exp->tq.cqh_first == (void *)&exp->tq) {
464 		/* Initialize the `local context' tag queue structure. */
465 		CALLOC_GOTO(sp, rtqp, TAGQ *, 1, sizeof(TAGQ));
466 		CIRCLEQ_INIT(&rtqp->tagq);
467 
468 		/* Initialize and link in its tag structure. */
469 		CALLOC_GOTO(sp, rtp, TAG *, 1, sizeof(TAG));
470 		CIRCLEQ_INSERT_HEAD(&rtqp->tagq, rtp, q);
471 		rtqp->current = rtp;
472 	}
473 
474 	/* Create the cscope command. */
475 	if ((tqp = create_cs_cmd(sp, pattern, &search)) == NULL)
476 		goto err;
477 
478 	/*
479 	 * Stick the current context in a convenient place, we'll lose it
480 	 * when we switch files.
481 	 */
482 	frp = sp->frp;
483 	lno = sp->lno;
484 	cno = sp->cno;
485 	istmp = F_ISSET(sp->frp, FR_TMPFILE) && !F_ISSET(cmdp, E_NEWSCREEN);
486 
487 	/* Search all open connections for a match. */
488 	matches = 0;
489 	for (csc = exp->cscq.lh_first; csc != NULL; csc = csc_next) {
490 		/* Copy csc->q.lh_next here in case csc is killed. */
491 		csc_next = csc->q.le_next;
492 
493 		/*
494 		 * Send the command to the cscope program.  (We skip the
495 		 * first two bytes of the command, because we stored the
496 		 * search cscope command character and a leading space
497 		 * there.)
498 		 */
499 		(void)fprintf(csc->to_fp, "%d%s\n", search, tqp->tag + 2);
500 		(void)fflush(csc->to_fp);
501 
502 		/* Read the output. */
503 		if (parse(sp, csc, tqp, &matches)) {
504 			if (rtqp != NULL)
505 				free(rtqp);
506 			tagq_free(sp, tqp);
507 			return (1);
508 		}
509 	}
510 
511 	if (matches == 0) {
512 		msgq(sp, M_INFO, "278|No matches for query");
513 		return (0);
514 	}
515 
516 	tqp->current = tqp->tagq.cqh_first;
517 
518 	/* Try to switch to the first tag. */
519 	force = FL_ISSET(cmdp->iflags, E_C_FORCE);
520 	if (F_ISSET(cmdp, E_NEWSCREEN)) {
521 		if (ex_tag_Nswitch(sp, tqp->current, force))
522 			goto err;
523 
524 		/* Everything else gets done in the new screen. */
525 		sp = sp->nextdisp;
526 		exp = EXP(sp);
527 	} else
528 		if (ex_tag_nswitch(sp, tqp->current, force))
529 			goto err;
530 
531 	/*
532 	 * If this is the first tag, put a `current location' queue entry
533 	 * in place, so we can pop all the way back to the current mark.
534 	 * Note, it doesn't point to much of anything, it's a placeholder.
535 	 */
536 	if (exp->tq.cqh_first == (void *)&exp->tq) {
537 		CIRCLEQ_INSERT_HEAD(&exp->tq, rtqp, q);
538 	} else
539 		rtqp = exp->tq.cqh_first;
540 
541 	/* Link the current TAGQ structure into place. */
542 	CIRCLEQ_INSERT_HEAD(&exp->tq, tqp, q);
543 
544 	(void)cscope_search(sp, tqp, tqp->current);
545 
546 	/*
547 	 * Move the current context from the temporary save area into the
548 	 * right structure.
549 	 *
550 	 * If we were in a temporary file, we don't have a context to which
551 	 * we can return, so just make it be the same as what we're moving
552 	 * to.  It will be a little odd that ^T doesn't change anything, but
553 	 * I don't think it's a big deal.
554 	 */
555 	if (istmp) {
556 		rtqp->current->frp = sp->frp;
557 		rtqp->current->lno = sp->lno;
558 		rtqp->current->cno = sp->cno;
559 	} else {
560 		rtqp->current->frp = frp;
561 		rtqp->current->lno = lno;
562 		rtqp->current->cno = cno;
563 	}
564 
565 	return (0);
566 
567 err:
568 alloc_err:
569 	if (rtqp != NULL)
570 		free(rtqp);
571 	if (rtp != NULL)
572 		free(rtp);
573 	return (1);
574 }
575 
576 /*
577  * create_cs_cmd --
578  *	Build a cscope command, creating and initializing the base TAGQ.
579  */
580 static TAGQ *
581 create_cs_cmd(sp, pattern, searchp)
582 	SCR *sp;
583 	char *pattern;
584 	size_t *searchp;
585 {
586 	CB *cbp;
587 	TAGQ *tqp;
588 	size_t tlen;
589 	char *p;
590 
591 	/*
592 	 * Cscope supports a "change pattern" command which we never use,
593 	 * cscope command 5.  Set CSCOPE_QUERIES[5] to " " since the user
594 	 * can't pass " " as the first character of pattern.  That way the
595 	 * user can't ask for pattern 5 so we don't need any special-case
596 	 * code.
597 	 */
598 #define	CSCOPE_QUERIES		"sgdct efi"
599 
600 	if (pattern == NULL)
601 		goto usage;
602 
603 	/* Skip leading blanks, check for command character. */
604 	for (; isblank(pattern[0]); ++pattern);
605 	if (pattern[0] == '\0' || !isblank(pattern[1]))
606 		goto usage;
607 	for (*searchp = 0, p = CSCOPE_QUERIES;
608 	    *p != '\0' && *p != pattern[0]; ++*searchp, ++p);
609 	if (*p == '\0') {
610 		msgq(sp, M_ERR,
611 		    "311|%s: unknown search type: use one of %s",
612 		    KEY_NAME(sp, pattern[0]), CSCOPE_QUERIES);
613 		return (NULL);
614 	}
615 
616 	/* Skip <blank> characters to the pattern. */
617 	for (p = pattern + 1; *p != '\0' && isblank(*p); ++p);
618 	if (*p == '\0') {
619 usage:		(void)csc_help(sp, "find");
620 		return (NULL);
621 	}
622 
623 	/* The user can specify the contents of a buffer as the pattern. */
624 	cbp = NULL;
625 	if (p[0] == '"' && p[1] != '\0' && p[2] == '\0')
626 		CBNAME(sp, cbp, p[1]);
627 	if (cbp != NULL) {
628 		p = cbp->textq.cqh_first->lb;
629 		tlen = cbp->textq.cqh_first->len;
630 	} else
631 		tlen = strlen(p);
632 
633 	/* Allocate and initialize the TAGQ structure. */
634 	CALLOC(sp, tqp, TAGQ *, 1, sizeof(TAGQ) + tlen + 3);
635 	if (tqp == NULL)
636 		return (NULL);
637 	CIRCLEQ_INIT(&tqp->tagq);
638 	tqp->tag = tqp->buf;
639 	tqp->tag[0] = pattern[0];
640 	tqp->tag[1] = ' ';
641 	tqp->tlen = tlen + 2;
642 	memcpy(tqp->tag + 2, p, tlen);
643 	tqp->tag[tlen + 2] = '\0';
644 	F_SET(tqp, TAG_CSCOPE);
645 
646 	return (tqp);
647 }
648 
649 /*
650  * parse --
651  *	Parse the cscope output.
652  */
653 static int
654 parse(sp, csc, tqp, matchesp)
655 	SCR *sp;
656 	CSC *csc;
657 	TAGQ *tqp;
658 	int *matchesp;
659 {
660 	TAG *tp;
661 	recno_t slno;
662 	size_t dlen, nlen, slen;
663 	int ch, i, isolder, nlines;
664 	char *dname, *name, *search, *p, *t, dummy[2], buf[2048];
665 
666 	for (;;) {
667 		if (!fgets(buf, sizeof(buf), csc->from_fp))
668 			goto io_err;
669 
670 		/*
671 		 * If the database is out of date, or there's some other
672 		 * problem, cscope will output error messages before the
673 		 * number-of-lines output.  Display/discard any output
674 		 * that doesn't match what we want.
675 		 */
676 #define	CSCOPE_NLINES_FMT	"cscope: %d lines%1[\n]"
677 		if (sscanf(buf, CSCOPE_NLINES_FMT, &nlines, dummy) == 2)
678 			break;
679 		if ((p = strchr(buf, '\n')) != NULL)
680 			*p = '\0';
681 		msgq(sp, M_ERR, "%s: \"%s\"", csc->dname, buf);
682 	}
683 
684 	while (nlines--) {
685 		if (fgets(buf, sizeof(buf), csc->from_fp) == NULL)
686 			goto io_err;
687 
688 		/* If the line's too long for the buffer, discard it. */
689 		if ((p = strchr(buf, '\n')) == NULL) {
690 			while ((ch = getc(csc->from_fp)) != EOF && ch != '\n');
691 			continue;
692 		}
693 		*p = '\0';
694 
695 		/*
696 		 * The cscope output is in the following format:
697 		 *
698 		 *	<filename> <context> <line number> <pattern>
699 		 *
700 		 * Figure out how long everything is so we can allocate in one
701 		 * swell foop, but discard anything that looks wrong.
702 		 */
703 		for (p = buf, i = 0;
704 		    i < 3 && (t = strsep(&p, "\t ")) != NULL; ++i)
705 			switch (i) {
706 			case 0:			/* Filename. */
707 				name = t;
708 				nlen = strlen(name);
709 				break;
710 			case 1:			/* Context. */
711 				break;
712 			case 2:			/* Line number. */
713 				slno = (recno_t)atol(t);
714 				break;
715 			}
716 		if (i != 3 || p == NULL || t == NULL)
717 			continue;
718 
719 		/* The rest of the string is the search pattern. */
720 		search = p;
721 		slen = strlen(p);
722 
723 		/* Resolve the file name. */
724 		csc_file(sp, csc, name, &dname, &dlen, &isolder);
725 
726 		/*
727 		 * If the file is older than the cscope database, that is,
728 		 * the database was built since the file was last modified,
729 		 * or there wasn't a search string, use the line number.
730 		 */
731 		if (isolder || strcmp(search, "<unknown>") == 0) {
732 			search = NULL;
733 			slen = 0;
734 		}
735 
736 		/*
737 		 * Allocate and initialize a tag structure plus the variable
738 		 * length cscope information that follows it.
739 		 */
740 		CALLOC_RET(sp, tp,
741 		    TAG *, 1, sizeof(TAG) + dlen + 2 + nlen + 1 + slen + 1);
742 		tp->fname = tp->buf;
743 		if (dlen != 0) {
744 			memcpy(tp->fname, dname, dlen);
745 			tp->fname[dlen] = '/';
746 			++dlen;
747 		}
748 		memcpy(tp->fname + dlen, name, nlen + 1);
749 		tp->fnlen = dlen + nlen;
750 		tp->slno = slno;
751 		if (slen != 0) {
752 			tp->search = tp->fname + tp->fnlen + 1;
753 			memcpy(tp->search, search, (tp->slen = slen) + 1);
754 		}
755 		CIRCLEQ_INSERT_TAIL(&tqp->tagq, tp, q);
756 
757 		++*matchesp;
758 	}
759 
760 	(void)read_prompt(sp, csc);
761 	return (0);
762 
763 io_err:	if (feof(csc->from_fp))
764 		errno = EIO;
765 	msgq_str(sp, M_SYSERR, "%s", csc->dname);
766 	terminate(sp, csc, 0);
767 	return (1);
768 }
769 
770 /*
771  * csc_file --
772  *	Search for the right path to this file.
773  */
774 static void
775 csc_file(sp, csc, name, dirp, dlenp, isolderp)
776 	SCR *sp;
777 	CSC *csc;
778 	char *name, **dirp;
779 	size_t *dlenp;
780 	int *isolderp;
781 {
782 	struct stat sb;
783 	char **pp, buf[MAXPATHLEN];
784 
785 	/*
786 	 * Check for the file in all of the listed paths.  If we don't
787 	 * find it, we simply return it unchanged.  We have to do this
788 	 * now, even though it's expensive, because if the user changes
789 	 * directories, we can't change our minds as to where the file
790 	 * lives.
791 	 */
792 	for (pp = csc->paths; *pp != NULL; ++pp) {
793 		(void)snprintf(buf, sizeof(buf), "%s/%s", *pp, name);
794 		if (stat(buf, &sb) == 0) {
795 			*dirp = *pp;
796 			*dlenp = strlen(*pp);
797 			*isolderp = sb.st_mtime < csc->mtime;
798 			return;
799 		}
800 	}
801 	*dlenp = 0;
802 }
803 
804 /*
805  * cscope_help --
806  *	The cscope help command.
807  */
808 static int
809 cscope_help(sp, cmdp, subcmd)
810 	SCR *sp;
811 	EXCMD *cmdp;
812 	char *subcmd;
813 {
814 	return (csc_help(sp, subcmd));
815 }
816 
817 /*
818  * csc_help --
819  *	Display help/usage messages.
820  */
821 static int
822 csc_help(sp, cmd)
823 	SCR *sp;
824 	char *cmd;
825 {
826 	CC const *ccp;
827 
828 	if (cmd != NULL && *cmd != '\0')
829 		if ((ccp = lookup_ccmd(cmd)) == NULL) {
830 			ex_printf(sp,
831 			    "%s doesn't match any cscope command\n", cmd);
832 			return (1);
833 		} else {
834 			ex_printf(sp,
835 		          "Command: %s (%s)\n", ccp->name, ccp->help_msg);
836 			ex_printf(sp, "  Usage: %s\n", ccp->usage_msg);
837 			return (0);
838 		}
839 
840 	ex_printf(sp, "cscope commands:\n");
841 	for (ccp = cscope_cmds; ccp->name != NULL; ++ccp)
842 		ex_printf(sp, "  %*s: %s\n", 5, ccp->name, ccp->help_msg);
843 	return (0);
844 }
845 
846 /*
847  * cscope_kill --
848  *	The cscope kill command.
849  */
850 static int
851 cscope_kill(sp, cmdp, cn)
852 	SCR *sp;
853 	EXCMD *cmdp;
854 	char *cn;
855 {
856 	return (terminate(sp, NULL, atoi(cn)));
857 }
858 
859 /*
860  * terminate --
861  *	Detach from a cscope process.
862  */
863 static int
864 terminate(sp, csc, n)
865 	SCR *sp;
866 	CSC *csc;
867 	int n;
868 {
869 	EX_PRIVATE *exp;
870 	int i, pstat;
871 
872 	exp = EXP(sp);
873 
874 	/*
875 	 * We either get a csc structure or a number.  If not provided a
876 	 * csc structure, find the right one.
877 	 */
878 	if (csc == NULL) {
879 		if (n < 1)
880 			goto badno;
881 		for (i = 1, csc = exp->cscq.lh_first;
882 		    csc != NULL; csc = csc->q.le_next, i++)
883 			if (i == n)
884 				break;
885 		if (csc == NULL) {
886 badno:			msgq(sp, M_ERR, "312|%d: no such cscope session", n);
887 			return (1);
888 		}
889 	}
890 
891 	/*
892 	 * XXX
893 	 * Theoretically, we have the only file descriptors to the process,
894 	 * so closing them should let it exit gracefully, deleting temporary
895 	 * files, etc.  The original vi cscope integration sent the cscope
896 	 * connection a SIGTERM signal, so I'm not sure if closing the file
897 	 * descriptors is sufficient.
898 	 */
899 	if (csc->from_fp != NULL)
900 		(void)fclose(csc->from_fp);
901 	if (csc->to_fp != NULL)
902 		(void)fclose(csc->to_fp);
903 	(void)waitpid(csc->pid, &pstat, 0);
904 
905 	/* Discard cscope connection information. */
906 	LIST_REMOVE(csc, q);
907 	if (csc->pbuf != NULL)
908 		free(csc->pbuf);
909 	if (csc->paths != NULL)
910 		free(csc->paths);
911 	free(csc);
912 	return (0);
913 }
914 
915 /*
916  * cscope_reset --
917  *	The cscope reset command.
918  */
919 static int
920 cscope_reset(sp, cmdp, notusedp)
921 	SCR *sp;
922 	EXCMD *cmdp;
923 	char *notusedp;
924 {
925 	EX_PRIVATE *exp;
926 
927 	for (exp = EXP(sp); exp->cscq.lh_first != NULL;)
928 		if (cscope_kill(sp, cmdp, "1"))
929 			return (1);
930 	return (0);
931 }
932 
933 /*
934  * cscope_display --
935  *	Display current connections.
936  *
937  * PUBLIC: int cscope_display __P((SCR *));
938  */
939 int
940 cscope_display(sp)
941 	SCR *sp;
942 {
943 	EX_PRIVATE *exp;
944 	CSC *csc;
945 	int i;
946 
947 	exp = EXP(sp);
948 	if (exp->cscq.lh_first == NULL) {
949 		ex_printf(sp, "No cscope connections.\n");
950 		return (0);
951 	}
952 	for (i = 1,
953 	    csc = exp->cscq.lh_first; csc != NULL; ++i, csc = csc->q.le_next)
954 		ex_printf(sp,
955 		    "%2d %s (process %lu)\n", i, csc->dname, (u_long)csc->pid);
956 	return (0);
957 }
958 
959 /*
960  * cscope_search --
961  *	Search a file for a cscope entry.
962  *
963  * PUBLIC: int cscope_search __P((SCR *, TAGQ *, TAG *));
964  */
965 int
966 cscope_search(sp, tqp, tp)
967 	SCR *sp;
968 	TAGQ *tqp;
969 	TAG *tp;
970 {
971 	MARK m;
972 
973 	/* If we don't have a search pattern, use the line number. */
974 	if (tp->search == NULL) {
975 		if (!db_exist(sp, tp->slno)) {
976 			tag_msg(sp, TAG_BADLNO, tqp->tag);
977 			return (1);
978 		}
979 		m.lno = tp->slno;
980 	} else {
981 		/*
982 		 * Search for the tag; cheap fallback for C functions
983 		 * if the name is the same but the arguments have changed.
984 		 */
985 		m.lno = 1;
986 		m.cno = 0;
987 		if (f_search(sp, &m, &m,
988 		    tp->search, tp->slen, NULL, SEARCH_CSCOPE | SEARCH_FILE)) {
989 			tag_msg(sp, TAG_SEARCH, tqp->tag);
990 			return (1);
991 		}
992 
993 		/*
994 		 * !!!
995 		 * Historically, tags set the search direction if it wasn't
996 		 * already set.
997 		 */
998 		if (sp->searchdir == NOTSET)
999 			sp->searchdir = FORWARD;
1000 	}
1001 
1002 	/*
1003 	 * !!!
1004 	 * Tags move to the first non-blank, NOT the search pattern start.
1005 	 */
1006 	sp->lno = m.lno;
1007 	sp->cno = 0;
1008 	(void)nonblank(sp, sp->lno, &sp->cno);
1009 	return (0);
1010 }
1011 
1012 
1013 /*
1014  * lookup_ccmd --
1015  *	Return a pointer to the command structure.
1016  */
1017 static CC const *
1018 lookup_ccmd(name)
1019 	char *name;
1020 {
1021 	CC const *ccp;
1022 	size_t len;
1023 
1024 	len = strlen(name);
1025 	for (ccp = cscope_cmds; ccp->name != NULL; ++ccp)
1026 		if (strncmp(name, ccp->name, len) == 0)
1027 			return (ccp);
1028 	return (NULL);
1029 }
1030 
1031 /*
1032  * read_prompt --
1033  *	Read a prompt from cscope.
1034  */
1035 static int
1036 read_prompt(sp, csc)
1037 	SCR *sp;
1038 	CSC *csc;
1039 {
1040 	int ch;
1041 
1042 #define	CSCOPE_PROMPT		">> "
1043 	for (;;) {
1044 		while ((ch =
1045 		    getc(csc->from_fp)) != EOF && ch != CSCOPE_PROMPT[0]);
1046 		if (ch == EOF) {
1047 			terminate(sp, csc, 0);
1048 			return (1);
1049 		}
1050 		if (getc(csc->from_fp) != CSCOPE_PROMPT[1])
1051 			continue;
1052 		if (getc(csc->from_fp) != CSCOPE_PROMPT[2])
1053 			continue;
1054 		break;
1055 	}
1056 	return (0);
1057 }
1058