xref: /freebsd/sbin/rcorder/rcorder.c (revision ae83180158c4c937f170e31eff311b18c0286a93)
1 /*	$NetBSD: rcorder.c,v 1.7 2000/08/04 07:33:55 enami Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 1999 Matthew R. Green
5  * All rights reserved.
6  * Copyright (c) 1998
7  * 	Perry E. Metzger.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project
20  *	by Perry E. Metzger.
21  * 4. The name of the author may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 
39 #include <err.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include <util.h>
45 
46 #include "ealloc.h"
47 #include "sprite.h"
48 #include "hash.h"
49 
50 #ifdef DEBUG
51 int debug = 0;
52 # define	DPRINTF(args) if (debug) { fflush(stdout); fprintf args; }
53 #else
54 # define	DPRINTF(args)
55 #endif
56 
57 #define REQUIRE_STR	"# REQUIRE:"
58 #define REQUIRE_LEN	(sizeof(REQUIRE_STR) - 1)
59 #define REQUIRES_STR	"# REQUIRES:"
60 #define REQUIRES_LEN	(sizeof(REQUIRES_STR) - 1)
61 #define PROVIDE_STR	"# PROVIDE:"
62 #define PROVIDE_LEN	(sizeof(PROVIDE_STR) - 1)
63 #define PROVIDES_STR	"# PROVIDES:"
64 #define PROVIDES_LEN	(sizeof(PROVIDES_STR) - 1)
65 #define BEFORE_STR	"# BEFORE:"
66 #define BEFORE_LEN	(sizeof(BEFORE_STR) - 1)
67 #define KEYWORD_STR	"# KEYWORD:"
68 #define KEYWORD_LEN	(sizeof(KEYWORD_STR) - 1)
69 #define KEYWORDS_STR	"# KEYWORDS:"
70 #define KEYWORDS_LEN	(sizeof(KEYWORDS_STR) - 1)
71 
72 int exit_code;
73 int file_count;
74 char **file_list;
75 
76 typedef int bool;
77 #define TRUE 1
78 #define FALSE 0
79 typedef bool flag;
80 #define SET TRUE
81 #define RESET FALSE
82 
83 Hash_Table provide_hash_s, *provide_hash;
84 
85 typedef struct provnode provnode;
86 typedef struct filenode filenode;
87 typedef struct f_provnode f_provnode;
88 typedef struct f_reqnode f_reqnode;
89 typedef struct strnodelist strnodelist;
90 
91 struct provnode {
92 	flag		head;
93 	flag		in_progress;
94 	filenode	*fnode;
95 	provnode	*next, *last;
96 };
97 
98 struct f_provnode {
99 	provnode	*pnode;
100 	f_provnode	*next;
101 };
102 
103 struct f_reqnode {
104 	Hash_Entry	*entry;
105 	f_reqnode	*next;
106 };
107 
108 struct strnodelist {
109 	filenode	*node;
110 	strnodelist	*next;
111 	char		s[1];
112 };
113 
114 struct filenode {
115 	char		*filename;
116 	flag		in_progress;
117 	filenode	*next, *last;
118 	f_reqnode	*req_list;
119 	f_provnode	*prov_list;
120 	strnodelist	*keyword_list;
121 };
122 
123 filenode fn_head_s, *fn_head;
124 
125 strnodelist *bl_list;
126 strnodelist *keep_list;
127 strnodelist *skip_list;
128 
129 void do_file __P((filenode *fnode));
130 void strnode_add __P((strnodelist **, char *, filenode *));
131 int skip_ok __P((filenode *fnode));
132 int keep_ok __P((filenode *fnode));
133 void satisfy_req __P((f_reqnode *rnode, char *filename));
134 void crunch_file __P((char *));
135 void parse_require __P((filenode *, char *));
136 void parse_provide __P((filenode *, char *));
137 void parse_before __P((filenode *, char *));
138 void parse_keywords __P((filenode *, char *));
139 filenode *filenode_new __P((char *));
140 void add_require __P((filenode *, char *));
141 void add_provide __P((filenode *, char *));
142 void add_before __P((filenode *, char *));
143 void add_keyword __P((filenode *, char *));
144 void insert_before __P((void));
145 Hash_Entry *make_fake_provision __P((filenode *));
146 void crunch_all_files __P((void));
147 void initialize __P((void));
148 void generate_ordering __P((void));
149 int main __P((int, char *[]));
150 
151 int
152 main(argc, argv)
153 	int argc;
154 	char *argv[];
155 {
156 	int ch;
157 
158 	while ((ch = getopt(argc, argv, "dk:s:")) != -1)
159 		switch (ch) {
160 		case 'd':
161 #ifdef DEBUG
162 			debug = 1;
163 #else
164 			warnx("debugging not compiled in, -d ignored");
165 #endif
166 			break;
167 		case 'k':
168 			strnode_add(&keep_list, optarg, 0);
169 			break;
170 		case 's':
171 			strnode_add(&skip_list, optarg, 0);
172 			break;
173 		default:
174 			/* XXX should crunch it? */
175 			break;
176 		}
177 	argc -= optind;
178 	argv += optind;
179 
180 	file_count = argc;
181 	file_list = argv;
182 
183 	DPRINTF((stderr, "parse_args\n"));
184 	initialize();
185 	DPRINTF((stderr, "initialize\n"));
186 	crunch_all_files();
187 	DPRINTF((stderr, "crunch_all_files\n"));
188 	generate_ordering();
189 	DPRINTF((stderr, "generate_ordering\n"));
190 
191 	exit(exit_code);
192 }
193 
194 /*
195  * initialise various variables.
196  */
197 void
198 initialize()
199 {
200 
201 	fn_head = &fn_head_s;
202 
203 	provide_hash = &provide_hash_s;
204 	Hash_InitTable(provide_hash, file_count);
205 }
206 
207 /* generic function to insert a new strnodelist element */
208 void
209 strnode_add(listp, s, fnode)
210 	strnodelist **listp;
211 	char *s;
212 	filenode *fnode;
213 {
214 	strnodelist *ent;
215 
216 	ent = emalloc(sizeof *ent + strlen(s));
217 	ent->node = fnode;
218 	strcpy(ent->s, s);
219 	ent->next = *listp;
220 	*listp = ent;
221 }
222 
223 /*
224  * below are the functions that deal with creating the lists
225  * from the filename's given and the dependancies and provisions
226  * in each of these files.  no ordering or checking is done here.
227  */
228 
229 /*
230  * we have a new filename, create a new filenode structure.
231  * fill in the bits, and put it in the filenode linked list
232  */
233 filenode *
234 filenode_new(filename)
235 	char *filename;
236 {
237 	filenode *temp;
238 
239 	temp = emalloc(sizeof(*temp));
240 	memset(temp, 0, sizeof(*temp));
241 	temp->filename = estrdup(filename);
242 	temp->req_list = NULL;
243 	temp->prov_list = NULL;
244 	temp->keyword_list = NULL;
245 	temp->in_progress = RESET;
246 	/*
247 	 * link the filenode into the list of filenodes.
248 	 * note that the double linking means we can delete a
249 	 * filenode without searching for where it belongs.
250 	 */
251 	temp->next = fn_head->next;
252 	if (temp->next != NULL)
253 		temp->next->last = temp;
254 	temp->last = fn_head;
255 	fn_head->next = temp;
256 	return (temp);
257 }
258 
259 /*
260  * add a requirement to a filenode.
261  */
262 void
263 add_require(fnode, s)
264 	filenode *fnode;
265 	char *s;
266 {
267 	Hash_Entry *entry;
268 	f_reqnode *rnode;
269 	int new;
270 
271 	entry = Hash_CreateEntry(provide_hash, s, &new);
272 	if (new)
273 		Hash_SetValue(entry, NULL);
274 	rnode = emalloc(sizeof(*rnode));
275 	rnode->entry = entry;
276 	rnode->next = fnode->req_list;
277 	fnode->req_list = rnode;
278 }
279 
280 /*
281  * add a provision to a filenode.  if this provision doesn't
282  * have a head node, create one here.
283  */
284 void
285 add_provide(fnode, s)
286 	filenode *fnode;
287 	char *s;
288 {
289 	Hash_Entry *entry;
290 	f_provnode *f_pnode;
291 	provnode *pnode, *head;
292 	int new;
293 
294 	entry = Hash_CreateEntry(provide_hash, s, &new);
295 	head = Hash_GetValue(entry);
296 
297 	/* create a head node if necessary. */
298 	if (head == NULL) {
299 		head = emalloc(sizeof(*head));
300 		head->head = SET;
301 		head->in_progress = RESET;
302 		head->fnode = NULL;
303 		head->last = head->next = NULL;
304 		Hash_SetValue(entry, head);
305 	}
306 #if 0
307 	/*
308 	 * Don't warn about this.  We want to be able to support
309 	 * scripts that do two complex things:
310 	 *
311 	 *	- Two independent scripts which both provide the
312 	 *	  same thing.  Both scripts must be executed in
313 	 *	  any order to meet the barrier.  An example:
314 	 *
315 	 *		Script 1:
316 	 *
317 	 *			PROVIDE: mail
318 	 *			REQUIRE: LOGIN
319 	 *
320 	 *		Script 2:
321 	 *
322 	 *			PROVIDE: mail
323 	 *			REQUIRE: LOGIN
324 	 *
325 	 * 	- Two interdependent scripts which both provide the
326 	 *	  same thing.  Both scripts must be executed in
327 	 *	  graph order to meet the barrier.  An example:
328 	 *
329 	 *		Script 1:
330 	 *
331 	 *			PROVIDE: nameservice dnscache
332 	 *			REQUIRE: SERVERS
333 	 *
334 	 *		Script 2:
335 	 *
336 	 *			PROVIDE: nameservice nscd
337 	 *			REQUIRE: dnscache
338 	 */
339 	else if (new == 0) {
340 		warnx("file `%s' provides `%s'.", fnode->filename, s);
341 		warnx("\tpreviously seen in `%s'.",
342 		    head->next->fnode->filename);
343 	}
344 #endif
345 
346 	pnode = emalloc(sizeof(*pnode));
347 	pnode->head = RESET;
348 	pnode->in_progress = RESET;
349 	pnode->fnode = fnode;
350 	pnode->next = head->next;
351 	pnode->last = head;
352 	head->next = pnode;
353 	if (pnode->next != NULL)
354 		pnode->next->last = pnode;
355 
356 	f_pnode = emalloc(sizeof(*f_pnode));
357 	f_pnode->pnode = pnode;
358 	f_pnode->next = fnode->prov_list;
359 	fnode->prov_list = f_pnode;
360 }
361 
362 /*
363  * put the BEFORE: lines to a list and handle them later.
364  */
365 void
366 add_before(fnode, s)
367 	filenode *fnode;
368 	char *s;
369 {
370 	strnodelist *bf_ent;
371 
372 	bf_ent = emalloc(sizeof *bf_ent + strlen(s));
373 	bf_ent->node = fnode;
374 	strcpy(bf_ent->s, s);
375 	bf_ent->next = bl_list;
376 	bl_list = bf_ent;
377 }
378 
379 /*
380  * add a key to a filenode.
381  */
382 void
383 add_keyword(fnode, s)
384 	filenode *fnode;
385 	char *s;
386 {
387 
388 	strnode_add(&fnode->keyword_list, s, fnode);
389 }
390 
391 /*
392  * loop over the rest of a REQUIRE line, giving each word to
393  * add_require() to do the real work.
394  */
395 void
396 parse_require(node, buffer)
397 	filenode *node;
398 	char *buffer;
399 {
400 	char *s;
401 
402 	while ((s = strsep(&buffer, " \t\n")) != NULL)
403 		if (*s != '\0')
404 			add_require(node, s);
405 }
406 
407 /*
408  * loop over the rest of a PROVIDE line, giving each word to
409  * add_provide() to do the real work.
410  */
411 void
412 parse_provide(node, buffer)
413 	filenode *node;
414 	char *buffer;
415 {
416 	char *s;
417 
418 	while ((s = strsep(&buffer, " \t\n")) != NULL)
419 		if (*s != '\0')
420 			add_provide(node, s);
421 }
422 
423 /*
424  * loop over the rest of a BEFORE line, giving each word to
425  * add_before() to do the real work.
426  */
427 void
428 parse_before(node, buffer)
429 	filenode *node;
430 	char *buffer;
431 {
432 	char *s;
433 
434 	while ((s = strsep(&buffer, " \t\n")) != NULL)
435 		if (*s != '\0')
436 			add_before(node, s);
437 }
438 
439 /*
440  * loop over the rest of a KEYWORD line, giving each word to
441  * add_keyword() to do the real work.
442  */
443 void
444 parse_keywords(node, buffer)
445 	filenode *node;
446 	char *buffer;
447 {
448 	char *s;
449 
450 	while ((s = strsep(&buffer, " \t\n")) != NULL)
451 		if (*s != '\0')
452 			add_keyword(node, s);
453 }
454 
455 /*
456  * given a file name, create a filenode for it, read in lines looking
457  * for provision and requirement lines, building the graphs as needed.
458  */
459 void
460 crunch_file(filename)
461 	char *filename;
462 {
463 	FILE *fp;
464 	char *buf;
465 	int require_flag, provide_flag, before_flag, keywords_flag;
466 	enum { BEFORE_PARSING, PARSING, PARSING_DONE } state;
467 	filenode *node;
468 	char delims[3] = { '\\', '\\', '\0' };
469 	struct stat st;
470 
471 	if ((fp = fopen(filename, "r")) == NULL) {
472 		warn("could not open %s", filename);
473 		return;
474 	}
475 
476 	if (fstat(fileno(fp), &st) == -1) {
477 		warn("could not stat %s", filename);
478 		fclose(fp);
479 		return;
480 	}
481 
482 	if (!S_ISREG(st.st_mode)) {
483 #if 0
484 		warnx("%s is not a file", filename);
485 #endif
486 		fclose(fp);
487 		return;
488 	}
489 
490 	node = filenode_new(filename);
491 
492 	/*
493 	 * we don't care about length, line number, don't want # for comments,
494 	 * and have no flags.
495 	 */
496 	for (state = BEFORE_PARSING; state != PARSING_DONE &&
497 	    (buf = fparseln(fp, NULL, NULL, delims, 0)) != NULL; free(buf)) {
498 		require_flag = provide_flag = before_flag = keywords_flag = 0;
499 		if (strncmp(REQUIRE_STR, buf, REQUIRE_LEN) == 0)
500 			require_flag = REQUIRE_LEN;
501 		else if (strncmp(REQUIRES_STR, buf, REQUIRES_LEN) == 0)
502 			require_flag = REQUIRES_LEN;
503 		else if (strncmp(PROVIDE_STR, buf, PROVIDE_LEN) == 0)
504 			provide_flag = PROVIDE_LEN;
505 		else if (strncmp(PROVIDES_STR, buf, PROVIDES_LEN) == 0)
506 			provide_flag = PROVIDES_LEN;
507 		else if (strncmp(BEFORE_STR, buf, BEFORE_LEN) == 0)
508 			before_flag = BEFORE_LEN;
509 		else if (strncmp(KEYWORD_STR, buf, KEYWORD_LEN) == 0)
510 			keywords_flag = KEYWORD_LEN;
511 		else if (strncmp(KEYWORDS_STR, buf, KEYWORDS_LEN) == 0)
512 			keywords_flag = KEYWORDS_LEN;
513 		else {
514 			if (state == PARSING)
515 				state = PARSING_DONE;
516 			continue;
517 		}
518 
519 		state = PARSING;
520 		if (require_flag)
521 			parse_require(node, buf + require_flag);
522 		else if (provide_flag)
523 			parse_provide(node, buf + provide_flag);
524 		else if (before_flag)
525 			parse_before(node, buf + before_flag);
526 		else if (keywords_flag)
527 			parse_keywords(node, buf + keywords_flag);
528 	}
529 	fclose(fp);
530 }
531 
532 Hash_Entry *
533 make_fake_provision(node)
534 	filenode *node;
535 {
536 	Hash_Entry *entry;
537 	f_provnode *f_pnode;
538 	provnode *head, *pnode;
539 	static	int i = 0;
540 	int	new;
541 	char buffer[30];
542 
543 	do {
544 		snprintf(buffer, sizeof buffer, "fake_prov_%08d", i++);
545 		entry = Hash_CreateEntry(provide_hash, buffer, &new);
546 	} while (new == 0);
547 	head = emalloc(sizeof(*head));
548 	head->head = SET;
549 	head->in_progress = RESET;
550 	head->fnode = NULL;
551 	head->last = head->next = NULL;
552 	Hash_SetValue(entry, head);
553 
554 	pnode = emalloc(sizeof(*pnode));
555 	pnode->head = RESET;
556 	pnode->in_progress = RESET;
557 	pnode->fnode = node;
558 	pnode->next = head->next;
559 	pnode->last = head;
560 	head->next = pnode;
561 	if (pnode->next != NULL)
562 		pnode->next->last = pnode;
563 
564 	f_pnode = emalloc(sizeof(*f_pnode));
565 	f_pnode->pnode = pnode;
566 	f_pnode->next = node->prov_list;
567 	node->prov_list = f_pnode;
568 
569 	return (entry);
570 }
571 
572 /*
573  * go through the BEFORE list, inserting requirements into the graph(s)
574  * as required.  in the before list, for each entry B, we have a file F
575  * and a string S.  we create a "fake" provision (P) that F provides.
576  * for each entry in the provision list for S, add a requirement to
577  * that provisions filenode for P.
578  */
579 void
580 insert_before()
581 {
582 	Hash_Entry *entry, *fake_prov_entry;
583 	provnode *pnode;
584 	f_reqnode *rnode;
585 	strnodelist *bl;
586 	int new;
587 
588 	while (bl_list != NULL) {
589 		bl = bl_list->next;
590 
591 		fake_prov_entry = make_fake_provision(bl_list->node);
592 
593 		entry = Hash_CreateEntry(provide_hash, bl_list->s, &new);
594 		if (new == 1)
595 			warnx("file `%s' is before unknown provision `%s'", bl_list->node->filename, bl_list->s);
596 
597 		for (pnode = Hash_GetValue(entry); pnode; pnode = pnode->next) {
598 			if (pnode->head)
599 				continue;
600 
601 			rnode = emalloc(sizeof(*rnode));
602 			rnode->entry = fake_prov_entry;
603 			rnode->next = pnode->fnode->req_list;
604 			pnode->fnode->req_list = rnode;
605 		}
606 
607 		free(bl_list);
608 		bl_list = bl;
609 	}
610 }
611 
612 /*
613  * loop over all the files calling crunch_file() on them to do the
614  * real work.  after we have built all the nodes, insert the BEFORE:
615  * lines into graph(s).
616  */
617 void
618 crunch_all_files()
619 {
620 	int i;
621 
622 	for (i = 0; i < file_count; i++)
623 		crunch_file(file_list[i]);
624 	insert_before();
625 }
626 
627 /*
628  * below are the functions that traverse the graphs we have built
629  * finding out the desired ordering, printing each file in turn.
630  * if missing requirements, or cyclic graphs are detected, a
631  * warning will be issued, and we will continue on..
632  */
633 
634 /*
635  * given a requirement node (in a filename) we attempt to satisfy it.
636  * we do some sanity checking first, to ensure that we have providers,
637  * aren't already satisfied and aren't already being satisfied (ie,
638  * cyclic).  if we pass all this, we loop over the provision list
639  * calling do_file() (enter recursion) for each filenode in this
640  * provision.
641  */
642 void
643 satisfy_req(rnode, filename)
644 	f_reqnode *rnode;
645 	char *filename;
646 {
647 	Hash_Entry *entry;
648 	provnode *head;
649 
650 	entry = rnode->entry;
651 	head = Hash_GetValue(entry);
652 
653 	if (head == NULL) {
654 		warnx("requirement `%s' in file `%s' has no providers.",
655 		    Hash_GetKey(entry), filename);
656 		exit_code = 1;
657 		return;
658 	}
659 
660 	/* return if the requirement is already satisfied. */
661 	if (head->next == NULL)
662 		return;
663 
664 	/*
665 	 * if list is marked as in progress,
666 	 *	print that there is a circular dependency on it and abort
667 	 */
668 	if (head->in_progress == SET) {
669 		warnx("Circular dependency on provision `%s' in file `%s'.",
670 		    Hash_GetKey(entry), filename);
671 		exit_code = 1;
672 		return;
673 	}
674 
675 	head->in_progress = SET;
676 
677 	/*
678 	 * while provision_list is not empty
679 	 *	do_file(first_member_of(provision_list));
680 	 */
681 	while (head->next != NULL)
682 		do_file(head->next->fnode);
683 }
684 
685 int
686 skip_ok(fnode)
687 	filenode *fnode;
688 {
689 	strnodelist *s;
690 	strnodelist *k;
691 
692 	for (s = skip_list; s; s = s->next)
693 		for (k = fnode->keyword_list; k; k = k->next)
694 			if (strcmp(k->s, s->s) == 0)
695 				return (0);
696 
697 	return (1);
698 }
699 
700 int
701 keep_ok(fnode)
702 	filenode *fnode;
703 {
704 	strnodelist *s;
705 	strnodelist *k;
706 
707 	for (s = keep_list; s; s = s->next)
708 		for (k = fnode->keyword_list; k; k = k->next)
709 			if (strcmp(k->s, s->s) == 0)
710 				return (1);
711 
712 	/* an empty keep_list means every one */
713 	return (!keep_list);
714 }
715 
716 /*
717  * given a filenode, we ensure we are not a cyclic graph.  if this
718  * is ok, we loop over the filenodes requirements, calling satisfy_req()
719  * for each of them.. once we have done this, remove this filenode
720  * from each provision table, as we are now done.
721  */
722 void
723 do_file(fnode)
724 	filenode *fnode;
725 {
726 	f_reqnode *r, *r_tmp;
727 	f_provnode *p, *p_tmp;
728 	provnode *pnode;
729 	int was_set;
730 
731 	DPRINTF((stderr, "do_file on %s.\n", fnode->filename));
732 
733 	/*
734 	 * if fnode is marked as in progress,
735 	 *	 print that fnode; is circularly depended upon and abort.
736 	 */
737 	if (fnode->in_progress == SET) {
738 		warnx("Circular dependency on file `%s'.",
739 			fnode->filename);
740 		was_set = exit_code = 1;
741 	} else
742 		was_set = 0;
743 
744 	/* mark fnode */
745 	fnode->in_progress = SET;
746 
747 	/*
748 	 * for each requirement of fnode -> r
749 	 *	satisfy_req(r, filename)
750 	 */
751 	r = fnode->req_list;
752 	while (r != NULL) {
753 		r_tmp = r;
754 		satisfy_req(r, fnode->filename);
755 		r = r->next;
756 		free(r_tmp);
757 	}
758 	fnode->req_list = NULL;
759 
760 	/*
761 	 * for each provision of fnode -> p
762 	 *	remove fnode from provision list for p in hash table
763 	 */
764 	p = fnode->prov_list;
765 	while (p != NULL) {
766 		p_tmp = p;
767 		pnode = p->pnode;
768 		if (pnode->next != NULL) {
769 			pnode->next->last = pnode->last;
770 		}
771 		if (pnode->last != NULL) {
772 			pnode->last->next = pnode->next;
773 		}
774 		free(pnode);
775 		p = p->next;
776 		free(p_tmp);
777 	}
778 	fnode->prov_list = NULL;
779 
780 	/* do_it(fnode) */
781 	DPRINTF((stderr, "next do: "));
782 
783 	/* if we were already in progress, don't print again */
784 	if (was_set == 0 && skip_ok(fnode) && keep_ok(fnode))
785 		printf("%s\n", fnode->filename);
786 
787 	if (fnode->next != NULL) {
788 		fnode->next->last = fnode->last;
789 	}
790 	if (fnode->last != NULL) {
791 		fnode->last->next = fnode->next;
792 	}
793 
794 	DPRINTF((stderr, "nuking %s\n", fnode->filename));
795 	free(fnode->filename);
796 	free(fnode);
797 }
798 
799 void
800 generate_ordering()
801 {
802 
803 	/*
804 	 * while there remain undone files{f},
805 	 *	pick an arbitrary f, and do_file(f)
806 	 * Note that the first file in the file list is perfectly
807 	 * arbitrary, and easy to find, so we use that.
808 	 */
809 
810 	/*
811 	 * N.B.: the file nodes "self delete" after they execute, so
812 	 * after each iteration of the loop, the head will be pointing
813 	 * to something totally different. The loop ends up being
814 	 * executed only once for every strongly connected set of
815 	 * nodes.
816 	 */
817 	while (fn_head->next != NULL) {
818 		DPRINTF((stderr, "generate on %s\n", fn_head->next->filename));
819 		do_file(fn_head->next);
820 	}
821 }
822