xref: /netbsd-src/sbin/rcorder/rcorder.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: rcorder.c,v 1.13 2004/09/21 15:47:32 rumble Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 1999 Matthew R. Green
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 /*
31  * Copyright (c) 1998
32  * 	Perry E. Metzger.  All rights reserved.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  * 3. All advertising materials mentioning features or use of this software
43  *    must display the following acknowledgement:
44  *	This product includes software developed for the NetBSD Project
45  *	by Perry E. Metzger.
46  * 4. The name of the author may not be used to endorse or promote products
47  *    derived from this software without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59  */
60 
61 #include <sys/types.h>
62 #include <sys/stat.h>
63 
64 #include <err.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 
70 #include "ealloc.h"
71 #include "hash.h"
72 
73 #ifdef DEBUG
74 int debug = 0;
75 # define	DPRINTF(args) if (debug) { fflush(stdout); fprintf args; }
76 #else
77 # define	DPRINTF(args)
78 #endif
79 
80 #define REQUIRE_STR	"# REQUIRE:"
81 #define REQUIRE_LEN	(sizeof(REQUIRE_STR) - 1)
82 #define REQUIRES_STR	"# REQUIRES:"
83 #define REQUIRES_LEN	(sizeof(REQUIRES_STR) - 1)
84 #define PROVIDE_STR	"# PROVIDE:"
85 #define PROVIDE_LEN	(sizeof(PROVIDE_STR) - 1)
86 #define PROVIDES_STR	"# PROVIDES:"
87 #define PROVIDES_LEN	(sizeof(PROVIDES_STR) - 1)
88 #define BEFORE_STR	"# BEFORE:"
89 #define BEFORE_LEN	(sizeof(BEFORE_STR) - 1)
90 #define KEYWORD_STR	"# KEYWORD:"
91 #define KEYWORD_LEN	(sizeof(KEYWORD_STR) - 1)
92 #define KEYWORDS_STR	"# KEYWORDS:"
93 #define KEYWORDS_LEN	(sizeof(KEYWORDS_STR) - 1)
94 
95 int exit_code;
96 int file_count;
97 char **file_list;
98 
99 enum {
100 	RESET	= 0,
101 	SET	= 1,
102 };
103 
104 Hash_Table provide_hash_s, *provide_hash;
105 
106 typedef struct provnode provnode;
107 typedef struct filenode filenode;
108 typedef struct f_provnode f_provnode;
109 typedef struct f_reqnode f_reqnode;
110 typedef struct strnodelist strnodelist;
111 
112 struct provnode {
113 	int		head;
114 	int		in_progress;
115 	filenode	*fnode;
116 	provnode	*next, *last;
117 };
118 
119 struct f_provnode {
120 	provnode	*pnode;
121 	f_provnode	*next;
122 };
123 
124 struct f_reqnode {
125 	Hash_Entry	*entry;
126 	f_reqnode	*next;
127 };
128 
129 struct strnodelist {
130 	filenode	*node;
131 	strnodelist	*next;
132 	char		s[1];
133 };
134 
135 struct filenode {
136 	char		*filename;
137 	int		in_progress;
138 	filenode	*next, *last;
139 	f_reqnode	*req_list;
140 	f_provnode	*prov_list;
141 	strnodelist	*keyword_list;
142 };
143 
144 filenode fn_head_s, *fn_head;
145 
146 strnodelist *bl_list;
147 strnodelist *keep_list;
148 strnodelist *skip_list;
149 
150 void do_file(filenode *fnode);
151 void strnode_add(strnodelist **, char *, filenode *);
152 int skip_ok(filenode *fnode);
153 int keep_ok(filenode *fnode);
154 void satisfy_req(f_reqnode *rnode, char *);
155 void crunch_file(char *);
156 void parse_line(filenode *, char *, void (*)(filenode *, char *));
157 filenode *filenode_new(char *);
158 void add_require(filenode *, char *);
159 void add_provide(filenode *, char *);
160 void add_before(filenode *, char *);
161 void add_keyword(filenode *, char *);
162 void insert_before(void);
163 Hash_Entry *make_fake_provision(filenode *);
164 void crunch_all_files(void);
165 void initialize(void);
166 void generate_ordering(void);
167 int main(int, char *[]);
168 
169 int
170 main(int argc, char *argv[])
171 {
172 	int ch;
173 
174 	while ((ch = getopt(argc, argv, "dk:s:")) != -1)
175 		switch (ch) {
176 		case 'd':
177 #ifdef DEBUG
178 			debug = 1;
179 #else
180 			warnx("debugging not compiled in, -d ignored");
181 #endif
182 			break;
183 		case 'k':
184 			strnode_add(&keep_list, optarg, 0);
185 			break;
186 		case 's':
187 			strnode_add(&skip_list, optarg, 0);
188 			break;
189 		default:
190 			/* XXX should crunch it? */
191 			break;
192 		}
193 	argc -= optind;
194 	argv += optind;
195 
196 	file_count = argc;
197 	file_list = argv;
198 
199 	DPRINTF((stderr, "parse_args\n"));
200 	initialize();
201 	DPRINTF((stderr, "initialize\n"));
202 	crunch_all_files();
203 	DPRINTF((stderr, "crunch_all_files\n"));
204 	generate_ordering();
205 	DPRINTF((stderr, "generate_ordering\n"));
206 
207 	exit(exit_code);
208 }
209 
210 /*
211  * initialise various variables.
212  */
213 void
214 initialize(void)
215 {
216 
217 	fn_head = &fn_head_s;
218 
219 	provide_hash = &provide_hash_s;
220 	Hash_InitTable(provide_hash, file_count);
221 }
222 
223 /* generic function to insert a new strnodelist element */
224 void
225 strnode_add(strnodelist **listp, char *s, filenode *fnode)
226 {
227 	strnodelist *ent;
228 
229 	ent = emalloc(sizeof *ent + strlen(s));
230 	ent->node = fnode;
231 	strcpy(ent->s, s);
232 	ent->next = *listp;
233 	*listp = ent;
234 }
235 
236 /*
237  * below are the functions that deal with creating the lists
238  * from the filename's given and the dependancies and provisions
239  * in each of these files.  no ordering or checking is done here.
240  */
241 
242 /*
243  * we have a new filename, create a new filenode structure.
244  * fill in the bits, and put it in the filenode linked list
245  */
246 filenode *
247 filenode_new(char *filename)
248 {
249 	filenode *temp;
250 
251 	temp = emalloc(sizeof(*temp));
252 	memset(temp, 0, sizeof(*temp));
253 	temp->filename = estrdup(filename);
254 	temp->req_list = NULL;
255 	temp->prov_list = NULL;
256 	temp->keyword_list = NULL;
257 	temp->in_progress = RESET;
258 	/*
259 	 * link the filenode into the list of filenodes.
260 	 * note that the double linking means we can delete a
261 	 * filenode without searching for where it belongs.
262 	 */
263 	temp->next = fn_head->next;
264 	if (temp->next != NULL)
265 		temp->next->last = temp;
266 	temp->last = fn_head;
267 	fn_head->next = temp;
268 	return (temp);
269 }
270 
271 /*
272  * add a requirement to a filenode.
273  */
274 void
275 add_require(filenode *fnode, char *s)
276 {
277 	Hash_Entry *entry;
278 	f_reqnode *rnode;
279 	int new;
280 
281 	entry = Hash_CreateEntry(provide_hash, s, &new);
282 	if (new)
283 		Hash_SetValue(entry, NULL);
284 	rnode = emalloc(sizeof(*rnode));
285 	rnode->entry = entry;
286 	rnode->next = fnode->req_list;
287 	fnode->req_list = rnode;
288 }
289 
290 /*
291  * add a provision to a filenode.  if this provision doesn't
292  * have a head node, create one here.
293  */
294 void
295 add_provide(filenode *fnode, char *s)
296 {
297 	Hash_Entry *entry;
298 	f_provnode *f_pnode;
299 	provnode *pnode, *head;
300 	int new;
301 
302 	entry = Hash_CreateEntry(provide_hash, s, &new);
303 	head = Hash_GetValue(entry);
304 
305 	/* create a head node if necessary. */
306 	if (head == NULL) {
307 		head = emalloc(sizeof(*head));
308 		head->head = SET;
309 		head->in_progress = RESET;
310 		head->fnode = NULL;
311 		head->last = head->next = NULL;
312 		Hash_SetValue(entry, head);
313 	}
314 #if 0
315 	/*
316 	 * Don't warn about this.  We want to be able to support
317 	 * scripts that do two complex things:
318 	 *
319 	 *	- Two independent scripts which both provide the
320 	 *	  same thing.  Both scripts must be executed in
321 	 *	  any order to meet the barrier.  An example:
322 	 *
323 	 *		Script 1:
324 	 *
325 	 *			PROVIDE: mail
326 	 *			REQUIRE: LOGIN
327 	 *
328 	 *		Script 2:
329 	 *
330 	 *			PROVIDE: mail
331 	 *			REQUIRE: LOGIN
332 	 *
333 	 * 	- Two interdependent scripts which both provide the
334 	 *	  same thing.  Both scripts must be executed in
335 	 *	  graph order to meet the barrier.  An example:
336 	 *
337 	 *		Script 1:
338 	 *
339 	 *			PROVIDE: nameservice dnscache
340 	 *			REQUIRE: SERVERS
341 	 *
342 	 *		Script 2:
343 	 *
344 	 *			PROVIDE: nameservice nscd
345 	 *			REQUIRE: dnscache
346 	 */
347 	else if (new == 0) {
348 		warnx("file `%s' provides `%s'.", fnode->filename, s);
349 		warnx("\tpreviously seen in `%s'.",
350 		    head->next->fnode->filename);
351 	}
352 #endif
353 
354 	pnode = emalloc(sizeof(*pnode));
355 	pnode->head = RESET;
356 	pnode->in_progress = RESET;
357 	pnode->fnode = fnode;
358 	pnode->next = head->next;
359 	pnode->last = head;
360 	head->next = pnode;
361 	if (pnode->next != NULL)
362 		pnode->next->last = pnode;
363 
364 	f_pnode = emalloc(sizeof(*f_pnode));
365 	f_pnode->pnode = pnode;
366 	f_pnode->next = fnode->prov_list;
367 	fnode->prov_list = f_pnode;
368 }
369 
370 /*
371  * put the BEFORE: lines to a list and handle them later.
372  */
373 void
374 add_before(filenode *fnode, char *s)
375 {
376 
377 	strnode_add(&bl_list, s, fnode);
378 }
379 
380 /*
381  * add a key to a filenode.
382  */
383 void
384 add_keyword(filenode *fnode, char *s)
385 {
386 
387 	strnode_add(&fnode->keyword_list, s, fnode);
388 }
389 
390 /*
391  * loop over the rest of a line, giving each word to
392  * add_func() to do the real work.
393  */
394 void
395 parse_line(filenode *node, char *buffer, void (*add_func)(filenode *, char *))
396 {
397 	char *s;
398 
399 	while ((s = strsep(&buffer, " \t\n")) != NULL)
400 		if (*s != '\0')
401 			(*add_func)(node, s);
402 }
403 
404 /*
405  * given a file name, create a filenode for it, read in lines looking
406  * for provision and requirement lines, building the graphs as needed.
407  */
408 void
409 crunch_file(char *filename)
410 {
411 	FILE *fp;
412 	char *buf;
413 	int require_flag, provide_flag, before_flag, keyword_flag;
414 	enum { BEFORE_PARSING, PARSING, PARSING_DONE } state;
415 	filenode *node;
416 	char delims[3] = { '\\', '\\', '\0' };
417 	struct stat st;
418 
419 	if ((fp = fopen(filename, "r")) == NULL) {
420 		warn("could not open %s", filename);
421 		return;
422 	}
423 
424 	if (fstat(fileno(fp), &st) == -1) {
425 		warn("could not stat %s", filename);
426 		fclose(fp);
427 		return;
428 	}
429 
430 	if (!S_ISREG(st.st_mode)) {
431 #if 0
432 		warnx("%s is not a file", filename);
433 #endif
434 		fclose(fp);
435 		return;
436 	}
437 
438 	node = filenode_new(filename);
439 
440 	/*
441 	 * we don't care about length, line number, don't want # for comments,
442 	 * and have no flags.
443 	 */
444 	for (state = BEFORE_PARSING; state != PARSING_DONE &&
445 	    (buf = fparseln(fp, NULL, NULL, delims, 0)) != NULL; free(buf)) {
446 		require_flag = provide_flag = before_flag = keyword_flag = 0;
447 		if (strncmp(REQUIRE_STR, buf, REQUIRE_LEN) == 0)
448 			require_flag = REQUIRE_LEN;
449 		else if (strncmp(REQUIRES_STR, buf, REQUIRES_LEN) == 0)
450 			require_flag = REQUIRES_LEN;
451 		else if (strncmp(PROVIDE_STR, buf, PROVIDE_LEN) == 0)
452 			provide_flag = PROVIDE_LEN;
453 		else if (strncmp(PROVIDES_STR, buf, PROVIDES_LEN) == 0)
454 			provide_flag = PROVIDES_LEN;
455 		else if (strncmp(BEFORE_STR, buf, BEFORE_LEN) == 0)
456 			before_flag = BEFORE_LEN;
457 		else if (strncmp(KEYWORD_STR, buf, KEYWORD_LEN) == 0)
458 			keyword_flag = KEYWORD_LEN;
459 		else if (strncmp(KEYWORDS_STR, buf, KEYWORDS_LEN) == 0)
460 			keyword_flag = KEYWORDS_LEN;
461 		else {
462 			if (state == PARSING)
463 				state = PARSING_DONE;
464 			continue;
465 		}
466 
467 		state = PARSING;
468 		if (require_flag)
469 			parse_line(node, buf + require_flag, add_require);
470 		else if (provide_flag)
471 			parse_line(node, buf + provide_flag, add_provide);
472 		else if (before_flag)
473 			parse_line(node, buf + before_flag,  add_before);
474 		else if (keyword_flag)
475 			parse_line(node, buf + keyword_flag, add_keyword);
476 	}
477 	fclose(fp);
478 }
479 
480 Hash_Entry *
481 make_fake_provision(filenode *node)
482 {
483 	Hash_Entry *entry;
484 	f_provnode *f_pnode;
485 	provnode *head, *pnode;
486 	static	int i = 0;
487 	int	new;
488 	char buffer[30];
489 
490 	do {
491 		snprintf(buffer, sizeof buffer, "fake_prov_%08d", i++);
492 		entry = Hash_CreateEntry(provide_hash, buffer, &new);
493 	} while (new == 0);
494 	head = emalloc(sizeof(*head));
495 	head->head = SET;
496 	head->in_progress = RESET;
497 	head->fnode = NULL;
498 	head->last = head->next = NULL;
499 	Hash_SetValue(entry, head);
500 
501 	pnode = emalloc(sizeof(*pnode));
502 	pnode->head = RESET;
503 	pnode->in_progress = RESET;
504 	pnode->fnode = node;
505 	pnode->next = head->next;
506 	pnode->last = head;
507 	head->next = pnode;
508 	if (pnode->next != NULL)
509 		pnode->next->last = pnode;
510 
511 	f_pnode = emalloc(sizeof(*f_pnode));
512 	f_pnode->pnode = pnode;
513 	f_pnode->next = node->prov_list;
514 	node->prov_list = f_pnode;
515 
516 	return (entry);
517 }
518 
519 /*
520  * go through the BEFORE list, inserting requirements into the graph(s)
521  * as required.  in the before list, for each entry B, we have a file F
522  * and a string S.  we create a "fake" provision (P) that F provides.
523  * for each entry in the provision list for S, add a requirement to
524  * that provisions filenode for P.
525  */
526 void
527 insert_before(void)
528 {
529 	Hash_Entry *entry, *fake_prov_entry;
530 	provnode *pnode;
531 	f_reqnode *rnode;
532 	strnodelist *bl;
533 	int new;
534 
535 	while (bl_list != NULL) {
536 		bl = bl_list->next;
537 
538 		fake_prov_entry = make_fake_provision(bl_list->node);
539 
540 		entry = Hash_CreateEntry(provide_hash, bl_list->s, &new);
541 		if (new == 1)
542 			warnx("file `%s' is before unknown provision `%s'",
543 			    bl_list->node->filename, bl_list->s);
544 
545 		for (pnode = Hash_GetValue(entry); pnode; pnode = pnode->next) {
546 			if (pnode->head)
547 				continue;
548 
549 			rnode = emalloc(sizeof(*rnode));
550 			rnode->entry = fake_prov_entry;
551 			rnode->next = pnode->fnode->req_list;
552 			pnode->fnode->req_list = rnode;
553 		}
554 
555 		free(bl_list);
556 		bl_list = bl;
557 	}
558 }
559 
560 /*
561  * loop over all the files calling crunch_file() on them to do the
562  * real work.  after we have built all the nodes, insert the BEFORE:
563  * lines into graph(s).
564  */
565 void
566 crunch_all_files(void)
567 {
568 	int i;
569 
570 	for (i = 0; i < file_count; i++)
571 		crunch_file(file_list[i]);
572 	insert_before();
573 }
574 
575 /*
576  * below are the functions that traverse the graphs we have built
577  * finding out the desired ordering, printing each file in turn.
578  * if missing requirements, or cyclic graphs are detected, a
579  * warning will be issued, and we will continue on..
580  */
581 
582 /*
583  * given a requirement node (in a filename) we attempt to satisfy it.
584  * we do some sanity checking first, to ensure that we have providers,
585  * aren't already satisfied and aren't already being satisfied (ie,
586  * cyclic).  if we pass all this, we loop over the provision list
587  * calling do_file() (enter recursion) for each filenode in this
588  * provision.
589  */
590 void
591 satisfy_req(f_reqnode *rnode, char *filename)
592 {
593 	Hash_Entry *entry;
594 	provnode *head;
595 
596 	entry = rnode->entry;
597 	head = Hash_GetValue(entry);
598 
599 	if (head == NULL) {
600 		warnx("requirement `%s' in file `%s' has no providers.",
601 		    Hash_GetKey(entry), filename);
602 		exit_code = 1;
603 		return;
604 	}
605 
606 	/* return if the requirement is already satisfied. */
607 	if (head->next == NULL)
608 		return;
609 
610 	/*
611 	 * if list is marked as in progress,
612 	 *	print that there is a circular dependency on it and abort
613 	 */
614 	if (head->in_progress == SET) {
615 		warnx("Circular dependency on provision `%s' in file `%s'.",
616 		    Hash_GetKey(entry), filename);
617 		exit_code = 1;
618 		return;
619 	}
620 
621 	head->in_progress = SET;
622 
623 	/*
624 	 * while provision_list is not empty
625 	 *	do_file(first_member_of(provision_list));
626 	 */
627 	while (head->next != NULL)
628 		do_file(head->next->fnode);
629 }
630 
631 int
632 skip_ok(filenode *fnode)
633 {
634 	strnodelist *s;
635 	strnodelist *k;
636 
637 	for (s = skip_list; s; s = s->next)
638 		for (k = fnode->keyword_list; k; k = k->next)
639 			if (strcmp(k->s, s->s) == 0)
640 				return (0);
641 
642 	return (1);
643 }
644 
645 int
646 keep_ok(filenode *fnode)
647 {
648 	strnodelist *s;
649 	strnodelist *k;
650 
651 	for (s = keep_list; s; s = s->next)
652 		for (k = fnode->keyword_list; k; k = k->next)
653 			if (strcmp(k->s, s->s) == 0)
654 				return (1);
655 
656 	/* an empty keep_list means every one */
657 	return (!keep_list);
658 }
659 
660 /*
661  * given a filenode, we ensure we are not a cyclic graph.  if this
662  * is ok, we loop over the filenodes requirements, calling satisfy_req()
663  * for each of them.. once we have done this, remove this filenode
664  * from each provision table, as we are now done.
665  */
666 void
667 do_file(filenode *fnode)
668 {
669 	f_reqnode *r, *r_tmp;
670 	f_provnode *p, *p_tmp;
671 	provnode *pnode;
672 	int was_set;
673 
674 	DPRINTF((stderr, "do_file on %s.\n", fnode->filename));
675 
676 	/*
677 	 * if fnode is marked as in progress,
678 	 *	 print that fnode; is circularly depended upon and abort.
679 	 */
680 	if (fnode->in_progress == SET) {
681 		warnx("Circular dependency on file `%s'.",
682 			fnode->filename);
683 		was_set = exit_code = 1;
684 	} else
685 		was_set = 0;
686 
687 	/* mark fnode */
688 	fnode->in_progress = SET;
689 
690 	/*
691 	 * for each requirement of fnode -> r
692 	 *	satisfy_req(r, filename)
693 	 */
694 	r = fnode->req_list;
695 	while (r != NULL) {
696 		r_tmp = r;
697 		satisfy_req(r, fnode->filename);
698 		r = r->next;
699 		free(r_tmp);
700 	}
701 	fnode->req_list = NULL;
702 
703 	/*
704 	 * for each provision of fnode -> p
705 	 *	remove fnode from provision list for p in hash table
706 	 */
707 	p = fnode->prov_list;
708 	while (p != NULL) {
709 		p_tmp = p;
710 		pnode = p->pnode;
711 		if (pnode->next != NULL) {
712 			pnode->next->last = pnode->last;
713 		}
714 		if (pnode->last != NULL) {
715 			pnode->last->next = pnode->next;
716 		}
717 		free(pnode);
718 		p = p->next;
719 		free(p_tmp);
720 	}
721 	fnode->prov_list = NULL;
722 
723 	/* do_it(fnode) */
724 	DPRINTF((stderr, "next do: "));
725 
726 	/* if we were already in progress, don't print again */
727 	if (was_set == 0 && skip_ok(fnode) && keep_ok(fnode))
728 		printf("%s\n", fnode->filename);
729 
730 	if (fnode->next != NULL) {
731 		fnode->next->last = fnode->last;
732 	}
733 	if (fnode->last != NULL) {
734 		fnode->last->next = fnode->next;
735 	}
736 
737 	DPRINTF((stderr, "nuking %s\n", fnode->filename));
738 	free(fnode->filename);
739 	free(fnode);
740 }
741 
742 void
743 generate_ordering(void)
744 {
745 
746 	/*
747 	 * while there remain undone files{f},
748 	 *	pick an arbitrary f, and do_file(f)
749 	 * Note that the first file in the file list is perfectly
750 	 * arbitrary, and easy to find, so we use that.
751 	 */
752 
753 	/*
754 	 * N.B.: the file nodes "self delete" after they execute, so
755 	 * after each iteration of the loop, the head will be pointing
756 	 * to something totally different. The loop ends up being
757 	 * executed only once for every strongly connected set of
758 	 * nodes.
759 	 */
760 	while (fn_head->next != NULL) {
761 		DPRINTF((stderr, "generate on %s\n", fn_head->next->filename));
762 		do_file(fn_head->next);
763 	}
764 }
765