xref: /freebsd/sbin/rcorder/rcorder.c (revision 2e3507c25e42292b45a5482e116d278f5515d04d)
1 # if 0
2 /*	$NetBSD: rcorder.c,v 1.7 2000/08/04 07:33:55 enami Exp $	*/
3 #endif
4 
5 /*-
6  * SPDX-License-Identifier: BSD-2-Clause
7  *
8  * Copyright (c) 1998, 1999 Matthew R. Green
9  * All rights reserved.
10  * Copyright (c) 1998
11  * 	Perry E. Metzger.  All rights reserved.
12  * Copyright (c) 2020
13  *     Boris N. Lytochkin. All rights reserved.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. All advertising materials mentioning features or use of this software
24  *    must display the following acknowledgement:
25  *	This product includes software developed for the NetBSD Project
26  *	by Perry E. Metzger.
27  * 4. The name of the author may not be used to endorse or promote products
28  *    derived from this software without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40  */
41 
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 
45 #include <err.h>
46 #include <stdio.h>
47 #include <libutil.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <libgen.h>
52 #include <stdbool.h>
53 
54 #include "ealloc.h"
55 #include "sprite.h"
56 #include "hash.h"
57 
58 #ifdef DEBUG
59 static int debug = 0;
60 # define	DPRINTF(args) if (debug) { fflush(stdout); fprintf args; }
61 #else
62 # define	DPRINTF(args)
63 #endif
64 
65 #define REQUIRE_STR	"# REQUIRE:"
66 #define REQUIRE_LEN	(sizeof(REQUIRE_STR) - 1)
67 #define REQUIRES_STR	"# REQUIRES:"
68 #define REQUIRES_LEN	(sizeof(REQUIRES_STR) - 1)
69 #define PROVIDE_STR	"# PROVIDE:"
70 #define PROVIDE_LEN	(sizeof(PROVIDE_STR) - 1)
71 #define PROVIDES_STR	"# PROVIDES:"
72 #define PROVIDES_LEN	(sizeof(PROVIDES_STR) - 1)
73 #define BEFORE_STR	"# BEFORE:"
74 #define BEFORE_LEN	(sizeof(BEFORE_STR) - 1)
75 #define KEYWORD_STR	"# KEYWORD:"
76 #define KEYWORD_LEN	(sizeof(KEYWORD_STR) - 1)
77 #define KEYWORDS_STR	"# KEYWORDS:"
78 #define KEYWORDS_LEN	(sizeof(KEYWORDS_STR) - 1)
79 
80 #define	FAKE_PROV_NAME	"fake_prov_"
81 
82 static int exit_code;
83 static int file_count;
84 static char **file_list;
85 
86 #define TRUE 1
87 #define FALSE 0
88 typedef bool flag;
89 #define SET TRUE
90 #define RESET FALSE
91 
92 static flag do_graphviz = false;
93 static flag do_parallel = false;
94 
95 static Hash_Table provide_hash_s, *provide_hash;
96 
97 typedef struct provnode provnode;
98 typedef struct filenode filenode;
99 typedef struct f_provnode f_provnode;
100 typedef struct f_reqnode f_reqnode;
101 typedef struct strnodelist strnodelist;
102 
103 struct provnode {
104 	flag		head;
105 	flag		in_progress;
106 	int		sequence;
107 	filenode	*fnode;
108 	provnode	*next, *last;
109 };
110 
111 struct f_provnode {
112 	provnode	*pnode;
113 	Hash_Entry	*entry;
114 	f_provnode	*next;
115 };
116 
117 struct f_reqnode {
118 	Hash_Entry	*entry;
119 	f_reqnode	*next;
120 };
121 
122 struct strnodelist {
123 	filenode	*node;
124 	strnodelist	*next;
125 	char		s[1];
126 };
127 
128 struct filenode {
129 	char		*filename;
130 	flag		in_progress;
131 	filenode	*next, *last;
132 	f_reqnode	*req_list;
133 	f_provnode	*prov_list;
134 	strnodelist	*keyword_list;
135 	int		issues_count;
136 	int		sequence;
137 };
138 
139 static filenode fn_head_s, *fn_head, **fn_seqlist;
140 static int max_sequence = 0;
141 
142 static strnodelist *bl_list;
143 static strnodelist *keep_list;
144 static strnodelist *skip_list;
145 
146 static void do_file(filenode *fnode, strnodelist *);
147 static void strnode_add(strnodelist **, char *, filenode *);
148 static int skip_ok(filenode *fnode);
149 static int keep_ok(filenode *fnode);
150 static char *generate_loop_for_req(strnodelist *, provnode *, filenode *);
151 static void satisfy_req(f_reqnode *rnode, filenode *fnode, strnodelist *);
152 static void crunch_file(char *);
153 static void parse_require(filenode *, char *);
154 static void parse_provide(filenode *, char *);
155 static void parse_before(filenode *, char *);
156 static void parse_keywords(filenode *, char *);
157 static filenode *filenode_new(char *);
158 static void add_require(filenode *, char *);
159 static void add_provide(filenode *, char *);
160 static void add_before(filenode *, char *);
161 static void add_keyword(filenode *, char *);
162 static void insert_before(void);
163 static Hash_Entry *make_fake_provision(filenode *);
164 static void crunch_all_files(void);
165 static void initialize(void);
166 static void generate_graphviz_header(void);
167 static void generate_graphviz_footer(void);
168 static void generate_graphviz_file_links(Hash_Entry *, filenode *);
169 static void generate_graphviz_providers(void);
170 static inline int is_fake_prov(const char *);
171 static int sequence_cmp(const void *, const void *);
172 static void generate_ordering(void);
173 
174 int
175 main(int argc, char *argv[])
176 {
177 	int ch;
178 
179 	while ((ch = getopt(argc, argv, "dgk:ps:")) != -1)
180 		switch (ch) {
181 		case 'd':
182 #ifdef DEBUG
183 			debug = 1;
184 #else
185 			warnx("debugging not compiled in, -d ignored");
186 #endif
187 			break;
188 		case 'g':
189 			do_graphviz = true;
190 			break;
191 		case 'k':
192 			strnode_add(&keep_list, optarg, 0);
193 			break;
194 		case 'p':
195 			do_parallel = true;
196 			break;
197 		case 's':
198 			strnode_add(&skip_list, optarg, 0);
199 			break;
200 		default:
201 			/* XXX should crunch it? */
202 			break;
203 		}
204 	argc -= optind;
205 	argv += optind;
206 
207 	file_count = argc;
208 	file_list = argv;
209 
210 	DPRINTF((stderr, "parse_args\n"));
211 	initialize();
212 	DPRINTF((stderr, "initialize\n"));
213 	generate_graphviz_header();
214 	crunch_all_files();
215 	DPRINTF((stderr, "crunch_all_files\n"));
216 	generate_graphviz_providers();
217 	generate_ordering();
218 	DPRINTF((stderr, "generate_ordering\n"));
219 	generate_graphviz_footer();
220 
221 	exit(exit_code);
222 }
223 
224 /*
225  * initialise various variables.
226  */
227 static void
228 initialize(void)
229 {
230 
231 	fn_head = &fn_head_s;
232 
233 	provide_hash = &provide_hash_s;
234 	Hash_InitTable(provide_hash, file_count);
235 }
236 
237 /* generic function to insert a new strnodelist element */
238 static void
239 strnode_add(strnodelist **listp, char *s, filenode *fnode)
240 {
241 	strnodelist *ent;
242 
243 	ent = emalloc(sizeof *ent + strlen(s));
244 	ent->node = fnode;
245 	strcpy(ent->s, s);
246 	ent->next = *listp;
247 	*listp = ent;
248 }
249 
250 /*
251  * below are the functions that deal with creating the lists
252  * from the filename's given dependencies and provisions
253  * in each of these files.  no ordering or checking is done here.
254  */
255 
256 /*
257  * we have a new filename, create a new filenode structure.
258  * fill in the bits, and put it in the filenode linked list
259  */
260 static filenode *
261 filenode_new(char *filename)
262 {
263 	filenode *temp;
264 
265 	temp = emalloc(sizeof(*temp));
266 	memset(temp, 0, sizeof(*temp));
267 	temp->filename = estrdup(filename);
268 	temp->req_list = NULL;
269 	temp->prov_list = NULL;
270 	temp->keyword_list = NULL;
271 	temp->in_progress = RESET;
272 	/*
273 	 * link the filenode into the list of filenodes.
274 	 * note that the double linking means we can delete a
275 	 * filenode without searching for where it belongs.
276 	 */
277 	temp->next = fn_head->next;
278 	if (temp->next != NULL)
279 		temp->next->last = temp;
280 	temp->last = fn_head;
281 	fn_head->next = temp;
282 	return (temp);
283 }
284 
285 /*
286  * add a requirement to a filenode.
287  */
288 static void
289 add_require(filenode *fnode, char *s)
290 {
291 	Hash_Entry *entry;
292 	f_reqnode *rnode;
293 	int new;
294 
295 	entry = Hash_CreateEntry(provide_hash, s, &new);
296 	if (new)
297 		Hash_SetValue(entry, NULL);
298 	rnode = emalloc(sizeof(*rnode));
299 	rnode->entry = entry;
300 	rnode->next = fnode->req_list;
301 	fnode->req_list = rnode;
302 }
303 
304 /*
305  * add a provision to a filenode.  if this provision doesn't
306  * have a head node, create one here.
307  */
308 static void
309 add_provide(filenode *fnode, char *s)
310 {
311 	Hash_Entry *entry;
312 	f_provnode *f_pnode;
313 	provnode *pnode, *head;
314 	int new;
315 
316 	entry = Hash_CreateEntry(provide_hash, s, &new);
317 	head = Hash_GetValue(entry);
318 
319 	/* create a head node if necessary. */
320 	if (head == NULL) {
321 		head = emalloc(sizeof(*head));
322 		head->head = SET;
323 		head->in_progress = RESET;
324 		head->fnode = NULL;
325 		head->sequence = 0;
326 		head->last = head->next = NULL;
327 		Hash_SetValue(entry, head);
328 	}
329 #if 0
330 	/*
331 	 * Don't warn about this.  We want to be able to support
332 	 * scripts that do two complex things:
333 	 *
334 	 *	- Two independent scripts which both provide the
335 	 *	  same thing.  Both scripts must be executed in
336 	 *	  any order to meet the barrier.  An example:
337 	 *
338 	 *		Script 1:
339 	 *
340 	 *			PROVIDE: mail
341 	 *			REQUIRE: LOGIN
342 	 *
343 	 *		Script 2:
344 	 *
345 	 *			PROVIDE: mail
346 	 *			REQUIRE: LOGIN
347 	 *
348 	 * 	- Two interdependent scripts which both provide the
349 	 *	  same thing.  Both scripts must be executed in
350 	 *	  graph order to meet the barrier.  An example:
351 	 *
352 	 *		Script 1:
353 	 *
354 	 *			PROVIDE: nameservice dnscache
355 	 *			REQUIRE: SERVERS
356 	 *
357 	 *		Script 2:
358 	 *
359 	 *			PROVIDE: nameservice nscd
360 	 *			REQUIRE: dnscache
361 	 */
362 	else if (new == 0) {
363 		warnx("file `%s' provides `%s'.", fnode->filename, s);
364 		warnx("\tpreviously seen in `%s'.",
365 		    head->next->fnode->filename);
366 	}
367 #endif
368 
369 	pnode = emalloc(sizeof(*pnode));
370 	pnode->head = RESET;
371 	pnode->in_progress = RESET;
372 	pnode->fnode = fnode;
373 	pnode->next = head->next;
374 	pnode->last = head;
375 	head->next = pnode;
376 	if (pnode->next != NULL)
377 		pnode->next->last = pnode;
378 
379 	f_pnode = emalloc(sizeof(*f_pnode));
380 	f_pnode->pnode = pnode;
381 	f_pnode->entry = entry;
382 	f_pnode->next = fnode->prov_list;
383 	fnode->prov_list = f_pnode;
384 }
385 
386 /*
387  * put the BEFORE: lines to a list and handle them later.
388  */
389 static void
390 add_before(filenode *fnode, char *s)
391 {
392 	strnodelist *bf_ent;
393 
394 	bf_ent = emalloc(sizeof *bf_ent + strlen(s));
395 	bf_ent->node = fnode;
396 	strcpy(bf_ent->s, s);
397 	bf_ent->next = bl_list;
398 	bl_list = bf_ent;
399 }
400 
401 /*
402  * add a key to a filenode.
403  */
404 static void
405 add_keyword(filenode *fnode, char *s)
406 {
407 
408 	strnode_add(&fnode->keyword_list, s, fnode);
409 }
410 
411 /*
412  * loop over the rest of a REQUIRE line, giving each word to
413  * add_require() to do the real work.
414  */
415 static void
416 parse_require(filenode *node, char *buffer)
417 {
418 	char *s;
419 
420 	while ((s = strsep(&buffer, " \t\n")) != NULL)
421 		if (*s != '\0')
422 			add_require(node, s);
423 }
424 
425 /*
426  * loop over the rest of a PROVIDE line, giving each word to
427  * add_provide() to do the real work.
428  */
429 static void
430 parse_provide(filenode *node, char *buffer)
431 {
432 	char *s;
433 
434 	while ((s = strsep(&buffer, " \t\n")) != NULL)
435 		if (*s != '\0')
436 			add_provide(node, s);
437 }
438 
439 /*
440  * loop over the rest of a BEFORE line, giving each word to
441  * add_before() to do the real work.
442  */
443 static void
444 parse_before(filenode *node, char *buffer)
445 {
446 	char *s;
447 
448 	while ((s = strsep(&buffer, " \t\n")) != NULL)
449 		if (*s != '\0')
450 			add_before(node, s);
451 }
452 
453 /*
454  * loop over the rest of a KEYWORD line, giving each word to
455  * add_keyword() to do the real work.
456  */
457 static void
458 parse_keywords(filenode *node, char *buffer)
459 {
460 	char *s;
461 
462 	while ((s = strsep(&buffer, " \t\n")) != NULL)
463 		if (*s != '\0')
464 			add_keyword(node, s);
465 }
466 
467 /*
468  * given a file name, create a filenode for it, read in lines looking
469  * for provision and requirement lines, building the graphs as needed.
470  */
471 static void
472 crunch_file(char *filename)
473 {
474 	FILE *fp;
475 	char *buf;
476 	int require_flag, provide_flag, before_flag, keywords_flag;
477 	enum { BEFORE_PARSING, PARSING, PARSING_DONE } state;
478 	filenode *node;
479 	char delims[3] = { '\\', '\\', '\0' };
480 	struct stat st;
481 
482 	if ((fp = fopen(filename, "r")) == NULL) {
483 		warn("could not open %s", filename);
484 		return;
485 	}
486 
487 	if (fstat(fileno(fp), &st) == -1) {
488 		warn("could not stat %s", filename);
489 		fclose(fp);
490 		return;
491 	}
492 
493 	if (!S_ISREG(st.st_mode)) {
494 #if 0
495 		warnx("%s is not a file", filename);
496 #endif
497 		fclose(fp);
498 		return;
499 	}
500 
501 	node = filenode_new(filename);
502 
503 	/*
504 	 * we don't care about length, line number, don't want # for comments,
505 	 * and have no flags.
506 	 */
507 	for (state = BEFORE_PARSING; state != PARSING_DONE &&
508 	    (buf = fparseln(fp, NULL, NULL, delims, 0)) != NULL; free(buf)) {
509 		require_flag = provide_flag = before_flag = keywords_flag = 0;
510 		if (strncmp(REQUIRE_STR, buf, REQUIRE_LEN) == 0)
511 			require_flag = REQUIRE_LEN;
512 		else if (strncmp(REQUIRES_STR, buf, REQUIRES_LEN) == 0)
513 			require_flag = REQUIRES_LEN;
514 		else if (strncmp(PROVIDE_STR, buf, PROVIDE_LEN) == 0)
515 			provide_flag = PROVIDE_LEN;
516 		else if (strncmp(PROVIDES_STR, buf, PROVIDES_LEN) == 0)
517 			provide_flag = PROVIDES_LEN;
518 		else if (strncmp(BEFORE_STR, buf, BEFORE_LEN) == 0)
519 			before_flag = BEFORE_LEN;
520 		else if (strncmp(KEYWORD_STR, buf, KEYWORD_LEN) == 0)
521 			keywords_flag = KEYWORD_LEN;
522 		else if (strncmp(KEYWORDS_STR, buf, KEYWORDS_LEN) == 0)
523 			keywords_flag = KEYWORDS_LEN;
524 		else {
525 			if (state == PARSING)
526 				state = PARSING_DONE;
527 			continue;
528 		}
529 
530 		state = PARSING;
531 		if (require_flag)
532 			parse_require(node, buf + require_flag);
533 		else if (provide_flag)
534 			parse_provide(node, buf + provide_flag);
535 		else if (before_flag)
536 			parse_before(node, buf + before_flag);
537 		else if (keywords_flag)
538 			parse_keywords(node, buf + keywords_flag);
539 	}
540 	fclose(fp);
541 }
542 
543 static Hash_Entry *
544 make_fake_provision(filenode *node)
545 {
546 	Hash_Entry *entry;
547 	f_provnode *f_pnode;
548 	provnode *head, *pnode;
549 	static	int i = 0;
550 	int	new;
551 	char buffer[30];
552 
553 	do {
554 		snprintf(buffer, sizeof buffer, FAKE_PROV_NAME "%08d", i++);
555 		entry = Hash_CreateEntry(provide_hash, buffer, &new);
556 	} while (new == 0);
557 	head = emalloc(sizeof(*head));
558 	head->head = SET;
559 	head->in_progress = RESET;
560 	head->fnode = NULL;
561 	head->last = head->next = NULL;
562 	Hash_SetValue(entry, head);
563 
564 	pnode = emalloc(sizeof(*pnode));
565 	pnode->head = RESET;
566 	pnode->in_progress = RESET;
567 	pnode->fnode = node;
568 	pnode->next = head->next;
569 	pnode->last = head;
570 	head->next = pnode;
571 	if (pnode->next != NULL)
572 		pnode->next->last = pnode;
573 
574 	f_pnode = emalloc(sizeof(*f_pnode));
575 	f_pnode->entry = entry;
576 	f_pnode->pnode = pnode;
577 	f_pnode->next = node->prov_list;
578 	node->prov_list = f_pnode;
579 
580 	return (entry);
581 }
582 
583 /*
584  * go through the BEFORE list, inserting requirements into the graph(s)
585  * as required.  in the before list, for each entry B, we have a file F
586  * and a string S.  we create a "fake" provision (P) that F provides.
587  * for each entry in the provision list for S, add a requirement to
588  * that provisions filenode for P.
589  */
590 static void
591 insert_before(void)
592 {
593 	Hash_Entry *entry, *fake_prov_entry;
594 	provnode *pnode;
595 	f_reqnode *rnode;
596 	strnodelist *bl;
597 	int new;
598 
599 	while (bl_list != NULL) {
600 		bl = bl_list->next;
601 
602 		fake_prov_entry = make_fake_provision(bl_list->node);
603 
604 		entry = Hash_CreateEntry(provide_hash, bl_list->s, &new);
605 		if (new == 1)
606 			warnx("file `%s' is before unknown provision `%s'", bl_list->node->filename, bl_list->s);
607 
608 		if (new == 1 && do_graphviz == true)
609 			generate_graphviz_file_links(
610 			    Hash_FindEntry(provide_hash, bl_list->s),
611 			    bl_list->node);
612 
613 		for (pnode = Hash_GetValue(entry); pnode; pnode = pnode->next) {
614 			if (pnode->head)
615 				continue;
616 
617 			rnode = emalloc(sizeof(*rnode));
618 			rnode->entry = fake_prov_entry;
619 			rnode->next = pnode->fnode->req_list;
620 			pnode->fnode->req_list = rnode;
621 		}
622 
623 		free(bl_list);
624 		bl_list = bl;
625 	}
626 }
627 
628 /*
629  * loop over all the files calling crunch_file() on them to do the
630  * real work.  after we have built all the nodes, insert the BEFORE:
631  * lines into graph(s).
632  */
633 static void
634 crunch_all_files(void)
635 {
636 	int i;
637 
638 	for (i = 0; i < file_count; i++)
639 		crunch_file(file_list[i]);
640 	insert_before();
641 }
642 
643 static inline int
644 is_fake_prov(const char *name)
645 {
646 
647 	return (name == strstr(name, FAKE_PROV_NAME));
648 }
649 
650 /* loop though provide list of vnode drawing all non-fake dependencies */
651 static void
652 generate_graphviz_file_links(Hash_Entry *entry, filenode *fnode)
653 {
654 	char *dep_name, *fname;
655 	provnode *head;
656 	f_provnode *fpnode, *rfpnode;
657 	int is_before = 0;
658 
659 	dep_name = Hash_GetKey(entry);
660 	if (is_fake_prov(dep_name))
661 		is_before = 1;
662 	head = Hash_GetValue(entry);
663 
664 	for (fpnode = fnode->prov_list; fpnode && fpnode->entry;
665 	    fpnode = fpnode->next) {
666 		fname = Hash_GetKey(fpnode->entry);
667 		if (is_fake_prov(fname))
668 			continue;
669 		rfpnode = NULL;
670 		do {
671 			if (rfpnode)
672 				dep_name = Hash_GetKey(rfpnode->entry);
673 			else
674 				dep_name = Hash_GetKey(entry);
675 
676 			if (!is_fake_prov(dep_name)) {
677 				printf("\"%s\" -> \"%s\" [%s%s];\n",
678 				    fname, dep_name,
679 				    /* edge style */
680 				    (is_before ? "style=dashed" : "style=solid"),
681 				    /* circular dep? */
682 				    ((head == NULL ||
683 				    (head->next && head->in_progress == SET)) ?
684 				    ", color=red, penwidth=4" : ""));
685 				if (rfpnode == NULL)
686 					break;
687 			}
688 			/* dependency is solved already */
689 			if (head == NULL || head->next == NULL)
690 				break;
691 
692 			if (rfpnode == NULL)
693 				rfpnode = head->next->fnode->prov_list;
694 			else
695 				rfpnode = rfpnode->next;
696 		} while (rfpnode);
697 	}
698 }
699 
700 /*
701  * Walk the stack, find the looping point and generate traceback.
702  * NULL is returned on failure, otherwize pointer to a buffer holding
703  * text representation is returned, caller must run free(3) for the
704  * pointer.
705  */
706 static char *
707 generate_loop_for_req(strnodelist *stack_tail, provnode *head,
708     filenode *fnode)
709 {
710 	provnode *pnode;
711 	strnodelist *stack_ptr, *loop_entry;
712 	char *buf, **revstack;
713 	size_t bufsize;
714 	int i, stack_depth;
715 
716 	loop_entry = NULL;
717 	/* fast forward stack to the component that is required now */
718 	for (pnode = head->next; pnode; pnode = pnode->next) {
719 		if (loop_entry)
720 			break;
721 		stack_depth = 0;
722 		for (stack_ptr = stack_tail; stack_ptr;
723 		    stack_ptr = stack_ptr->next) {
724 			stack_depth++;
725 			if (stack_ptr->node == pnode->fnode) {
726 				loop_entry = stack_ptr;
727 				break;
728 			}
729 		}
730 	}
731 
732 	if (loop_entry == NULL)
733 		return (NULL);
734 
735 	stack_depth += 2; /* fnode + loop_entry */
736 	revstack = emalloc(sizeof(char *) * stack_depth);
737 	bzero(revstack, (sizeof(char *) * stack_depth));
738 
739 	/* reverse stack and estimate buffer size to allocate */
740 	bufsize = 1; /* tralining \0 */
741 
742 	revstack[stack_depth - 1] = loop_entry->node->filename;
743 	bufsize += strlen(revstack[stack_depth - 1]);
744 
745 	revstack[stack_depth - 2] = fnode->filename;
746 	bufsize += strlen(revstack[stack_depth - 2]);
747 	fnode->issues_count++;
748 
749 	stack_ptr = stack_tail;
750 	for (i = stack_depth - 3; i >= 0; i--) {
751 		revstack[i] = stack_ptr->node->filename;
752 		stack_ptr->node->issues_count++;
753 		stack_ptr = stack_ptr->next;
754 		bufsize += strlen(revstack[i]);
755 	}
756 	bufsize += strlen(" -> ") * (stack_depth - 1);
757 
758 	buf = emalloc(bufsize);
759 	bzero(buf, bufsize);
760 
761 	for (i = 0; i < stack_depth; i++) {
762 		strlcat(buf, revstack[i], bufsize);
763 		if (i < stack_depth - 1)
764 			strlcat(buf, " -> ", bufsize);
765 	}
766 
767 	free(revstack);
768 	return (buf);
769 }
770 /*
771  * below are the functions that traverse the graphs we have built
772  * finding out the desired ordering, printing each file in turn.
773  * if missing requirements, or cyclic graphs are detected, a
774  * warning will be issued, and we will continue on..
775  */
776 
777 /*
778  * given a requirement node (in a filename) we attempt to satisfy it.
779  * we do some sanity checking first, to ensure that we have providers,
780  * aren't already satisfied and aren't already being satisfied (ie,
781  * cyclic).  if we pass all this, we loop over the provision list
782  * calling do_file() (enter recursion) for each filenode in this
783  * provision.
784  */
785 static void
786 satisfy_req(f_reqnode *rnode, filenode *fnode, strnodelist *stack_ptr)
787 {
788 	Hash_Entry *entry;
789 	provnode *head;
790 	strnodelist stack_item;
791 	char *buf;
792 
793 	entry = rnode->entry;
794 	head = Hash_GetValue(entry);
795 
796 	if (do_graphviz == true)
797 		generate_graphviz_file_links(entry, fnode);
798 
799 	if (head == NULL) {
800 		warnx("requirement `%s' in file `%s' has no providers.",
801 		    Hash_GetKey(entry), fnode->filename);
802 		exit_code = 1;
803 		return;
804 	}
805 
806 	/* return if the requirement is already satisfied. */
807 	if (head->next == NULL)
808 		return;
809 
810 	/*
811 	 * if list is marked as in progress,
812 	 *	print that there is a circular dependency on it and abort
813 	 */
814 	if (head->in_progress == SET) {
815 		exit_code = 1;
816 		buf = generate_loop_for_req(stack_ptr, head,
817 		    fnode);
818 
819 		if (buf == NULL) {
820 			warnx("Circular dependency on provision `%s' in "
821 			    "file `%s' (tracing has failed).",
822 			    Hash_GetKey(entry), fnode->filename);
823 			return;
824 		}
825 
826 		warnx("Circular dependency on provision `%s': %s.",
827 		    Hash_GetKey(entry), buf);
828 		free(buf);
829 		return;
830 	}
831 
832 	head->in_progress = SET;
833 
834 	stack_item.next = stack_ptr;
835 	stack_item.node = fnode;
836 
837 	/*
838 	 * while provision_list is not empty
839 	 *	do_file(first_member_of(provision_list));
840 	 */
841 	while (head->next != NULL)
842 		do_file(head->next->fnode, &stack_item);
843 }
844 
845 static int
846 skip_ok(filenode *fnode)
847 {
848 	strnodelist *s;
849 	strnodelist *k;
850 
851 	for (s = skip_list; s; s = s->next)
852 		for (k = fnode->keyword_list; k; k = k->next)
853 			if (strcmp(k->s, s->s) == 0)
854 				return (0);
855 
856 	return (1);
857 }
858 
859 static int
860 keep_ok(filenode *fnode)
861 {
862 	strnodelist *s;
863 	strnodelist *k;
864 
865 	for (s = keep_list; s; s = s->next)
866 		for (k = fnode->keyword_list; k; k = k->next)
867 			if (strcmp(k->s, s->s) == 0)
868 				return (1);
869 
870 	/* an empty keep_list means every one */
871 	return (!keep_list);
872 }
873 
874 /*
875  * given a filenode, we ensure we are not a cyclic graph.  if this
876  * is ok, we loop over the filenodes requirements, calling satisfy_req()
877  * for each of them.. once we have done this, remove this filenode
878  * from each provision table, as we are now done.
879  *
880  * NOTE: do_file() is called recursively from several places and cannot
881  * safely free() anything related to items that may be recursed on.
882  * Circular dependencies will cause problems if we do.
883  */
884 static void
885 do_file(filenode *fnode, strnodelist *stack_ptr)
886 {
887 	f_reqnode *r;
888 	f_provnode *p, *p_tmp;
889 	provnode *pnode, *head;
890 	int was_set;
891 	char *dep_name;
892 
893 	DPRINTF((stderr, "do_file on %s.\n", fnode->filename));
894 
895 	/*
896 	 * if fnode is marked as in progress,
897 	 *	 print that fnode; is circularly depended upon and abort.
898 	 */
899 	if (fnode->in_progress == SET) {
900 		warnx("Circular dependency on file `%s'.",
901 			fnode->filename);
902 		was_set = exit_code = 1;
903 	} else
904 		was_set = 0;
905 
906 	/* mark fnode */
907 	fnode->in_progress = SET;
908 
909 	/*
910 	 * for each requirement of fnode -> r
911 	 *	satisfy_req(r, filename)
912 	 */
913 	r = fnode->req_list;
914 	fnode->sequence = 0;
915 	while (r != NULL) {
916 		satisfy_req(r, fnode, stack_ptr);
917 		/* find sequence number where all requirements are satisfied */
918 		head = Hash_GetValue(r->entry);
919 		if (head && head->sequence > fnode->sequence)
920 			fnode->sequence = head->sequence;
921 		r = r->next;
922 	}
923 	fnode->req_list = NULL;
924 	fnode->sequence++;
925 
926 	/* if we've seen issues with this file - put it to the tail */
927 	if (fnode->issues_count)
928 		fnode->sequence = max_sequence + 1;
929 
930 	if (max_sequence < fnode->sequence)
931 		max_sequence = fnode->sequence;
932 
933 	/*
934 	 * for each provision of fnode -> p
935 	 *	remove fnode from provision list for p in hash table
936 	 */
937 	p = fnode->prov_list;
938 	while (p != NULL) {
939 		/* mark all troublemakers on graphviz */
940 		if (do_graphviz == true && fnode->issues_count) {
941 			dep_name = Hash_GetKey(p->entry);
942 			if (!is_fake_prov(dep_name))
943 				printf("\"%s\" [ color=red, penwidth=4 ];\n",
944 				    dep_name);
945 		}
946 
947 		/* update sequence when provided requirements are satisfied */
948 		head = Hash_GetValue(p->entry);
949 		if (head->sequence < fnode->sequence)
950 			head->sequence = fnode->sequence;
951 
952 		p_tmp = p;
953 		pnode = p->pnode;
954 		if (pnode->next != NULL) {
955 			pnode->next->last = pnode->last;
956 		}
957 		if (pnode->last != NULL) {
958 			pnode->last->next = pnode->next;
959 		}
960 		free(pnode);
961 		p = p->next;
962 		free(p_tmp);
963 	}
964 	fnode->prov_list = NULL;
965 
966 	/* do_it(fnode) */
967 	DPRINTF((stderr, "next do: "));
968 
969 	/* if we were already in progress, don't print again */
970 	if (do_graphviz != true && was_set == 0 && skip_ok(fnode) &&
971 	    keep_ok(fnode)) {
972 		*fn_seqlist = fnode;
973 		fn_seqlist++;
974 	}
975 
976 	if (fnode->next != NULL) {
977 		fnode->next->last = fnode->last;
978 	}
979 	if (fnode->last != NULL) {
980 		fnode->last->next = fnode->next;
981 	}
982 
983 	if (fnode->issues_count)
984 		warnx("`%s' was seen in circular dependencies for %d times.",
985 		    fnode->filename, fnode->issues_count);
986 
987 	DPRINTF((stderr, "nuking %s\n", fnode->filename));
988 }
989 
990 static void
991 generate_graphviz_header(void)
992 {
993 
994 	if (do_graphviz != true)
995 		return;
996 
997 	printf("digraph rcorder {\n"
998 	    "rankdir=\"BT\";\n"
999 	    "node [style=rounded, shape=record];\n"
1000 	    "graph [overlap = false];\n");
1001 }
1002 
1003 static void
1004 generate_graphviz_footer(void)
1005 {
1006 
1007 	if (do_graphviz == true)
1008 		printf("}\n");
1009 }
1010 
1011 static void
1012 generate_graphviz_providers(void)
1013 {
1014 	Hash_Entry *entry;
1015 	Hash_Search psearch;
1016 	provnode *head, *pnode;
1017 	char *dep_name;
1018 
1019 	if (do_graphviz != true)
1020 		return;
1021 
1022 	entry = Hash_EnumFirst(provide_hash, &psearch);
1023 	if (entry == NULL)
1024 		return;
1025 
1026 	do {
1027 		dep_name = Hash_GetKey(entry);
1028 		if (is_fake_prov(dep_name))
1029 			continue;
1030 		head = Hash_GetValue(entry);
1031 		/* no providers for this requirement */
1032 		if (head == NULL || head->next == NULL) {
1033 			printf("\"%s\" [label=\"{ %s | ENOENT }\", "
1034 			    "style=\"rounded,filled\", color=red];\n",
1035 			    dep_name, dep_name);
1036 			continue;
1037 		}
1038 		/* one PROVIDE word for one file that matches */
1039 		if (head->next->next == NULL &&
1040 		    strcmp(dep_name,
1041 		    basename(head->next->fnode->filename)) == 0) {
1042 		        continue;
1043 		}
1044 		printf("\"%s\" [label=\"{ %s | ", dep_name, dep_name);
1045 		for (pnode = head->next; pnode; pnode = pnode->next)
1046 			printf("%s\\n", basename(pnode->fnode->filename));
1047 
1048 		printf("}\"];\n");
1049 	} while (NULL != (entry = Hash_EnumNext(&psearch)));
1050 }
1051 
1052 static int
1053 sequence_cmp(const void *a, const void *b)
1054 {
1055 	const filenode *fna = *((const filenode * const *)a);
1056 	const filenode *fnb = *((const filenode * const *)b);
1057 	int left, right;
1058 
1059 	/* push phantom files to the end */
1060 	if (fna == NULL || fnb == NULL)
1061 		return ((fna < fnb) - (fna > fnb));
1062 
1063 	left =  fna->sequence;
1064 	right = fnb->sequence;
1065 
1066 	return ((left > right) - (left < right));
1067 }
1068 
1069 static void
1070 generate_ordering(void)
1071 {
1072 	filenode **seqlist, **psl;
1073 	int last_seq = 0;
1074 
1075 	/* Prepare order buffer, use an additional one as a list terminator */
1076 	seqlist = emalloc(sizeof(filenode *) * (file_count + 1));
1077 	bzero(seqlist, sizeof(filenode *) * (file_count + 1));
1078 	fn_seqlist = seqlist;
1079 
1080 	/*
1081 	 * while there remain undone files{f},
1082 	 *	pick an arbitrary f, and do_file(f)
1083 	 * Note that the first file in the file list is perfectly
1084 	 * arbitrary, and easy to find, so we use that.
1085 	 */
1086 
1087 	/*
1088 	 * N.B.: the file nodes "self delete" after they execute, so
1089 	 * after each iteration of the loop, the head will be pointing
1090 	 * to something totally different. The loop ends up being
1091 	 * executed only once for every strongly connected set of
1092 	 * nodes.
1093 	 */
1094 	while (fn_head->next != NULL) {
1095 		DPRINTF((stderr, "generate on %s\n", fn_head->next->filename));
1096 		do_file(fn_head->next, NULL);
1097 	}
1098 
1099 	/* Sort filenode list based on sequence */
1100 	qsort(seqlist, file_count, sizeof(filenode *), sequence_cmp);
1101 
1102 	for (psl = seqlist; *psl; psl++) {
1103 		printf("%s%s",
1104 		    (last_seq == 0 ? "" :
1105 		    (do_parallel != true || last_seq != (*psl)->sequence) ?
1106 		    "\n" : " "),
1107 		(*psl)->filename);
1108 		last_seq = (*psl)->sequence;
1109 		free((*psl)->filename);
1110 		free(*psl);
1111 	}
1112 	if (last_seq)
1113 		printf("\n");
1114 
1115 	free(seqlist);
1116 }
1117