xref: /openbsd/usr.bin/make/dir.c (revision c9fc29cf)
1 /*	$OpenBSD: dir.c,v 1.69 2023/09/04 11:35:11 espie Exp $ */
2 /*	$NetBSD: dir.c,v 1.14 1997/03/29 16:51:26 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1999 Marc Espie.
6  *
7  * Extensive code changes for the OpenBSD project.
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  *
18  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
22  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 /*
31  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
32  * Copyright (c) 1988, 1989 by Adam de Boor
33  * Copyright (c) 1989 by Berkeley Softworks
34  * All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * Adam de Boor.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  */
63 
64 #include <sys/stat.h>
65 #include <dirent.h>
66 #include <limits.h>
67 #include <stddef.h>
68 #include <stdint.h>
69 #include <stdio.h>
70 #include <stdlib.h>
71 #include <string.h>
72 #include <ohash.h>
73 #include "defines.h"
74 #include "dir.h"
75 #include "lst.h"
76 #include "memory.h"
77 #include "buf.h"
78 #include "gnode.h"
79 #include "arch.h"
80 #include "targ.h"
81 #include "error.h"
82 #include "str.h"
83 #include "timestamp.h"
84 
85 
86 /*	A search path consists of a Lst of PathEntry structures. A Path
87  *	structure has in it the name of the directory and a hash table of all
88  *	the files in the directory. This is used to cut down on the number of
89  *	system calls necessary to find implicit dependents and their like.
90  *	Since these searches are made before any actions are taken, we need not
91  *	worry about the directory changing due to creation commands. If this
92  *	hampers the style of some makefiles, they must be changed.
93  *
94  *	A list of all previously-read directories is kept in the
95  *	knownDirectories cache.
96  *
97  *	The need for the caching of whole directories is brought about by
98  *	the multi-level transformation code in suff.c, which tends to search
99  *	for far more files than regular make does. In the initial
100  *	implementation, the amount of time spent performing "stat" calls was
101  *	truly astronomical. The problem with hashing at the start is,
102  *	of course, that pmake doesn't then detect changes to these directories
103  *	during the course of the make. Three possibilities suggest themselves:
104  *
105  *	    1) just use stat to test for a file's existence. As mentioned
106  *	       above, this is very inefficient due to the number of checks
107  *	       engendered by the multi-level transformation code.
108  *	    2) use readdir() and company to search the directories, keeping
109  *	       them open between checks. I have tried this and while it
110  *	       didn't slow down the process too much, it could severely
111  *	       affect the amount of parallelism available as each directory
112  *	       open would take another file descriptor out of play for
113  *	       handling I/O for another job. Given that it is only recently
114  *	       that UNIX OS's have taken to allowing more than 20 or 32
115  *	       file descriptors for a process, this doesn't seem acceptable
116  *	       to me.
117  *	    3) record the mtime of the directory in the PathEntry structure and
118  *	       verify the directory hasn't changed since the contents were
119  *	       hashed. This will catch the creation or deletion of files,
120  *	       but not the updating of files. However, since it is the
121  *	       creation and deletion that is the problem, this could be
122  *	       a good thing to do. Unfortunately, if the directory (say ".")
123  *	       were fairly large and changed fairly frequently, the constant
124  *	       rehashing could seriously degrade performance. It might be
125  *	       good in such cases to keep track of the number of rehashes
126  *	       and if the number goes over a (small) limit, resort to using
127  *	       stat in its place.
128  *
129  *	An additional thing to consider is that pmake is used primarily
130  *	to create C programs and until recently pcc-based compilers refused
131  *	to allow you to specify where the resulting object file should be
132  *	placed. This forced all objects to be created in the current
133  *	directory. This isn't meant as a full excuse, just an explanation of
134  *	some of the reasons for the caching used here.
135  *
136  *	One more note: the location of a target's file is only performed
137  *	on the downward traversal of the graph and then only for terminal
138  *	nodes in the graph. This could be construed as wrong in some cases,
139  *	but prevents inadvertent modification of files when the "installed"
140  *	directory for a file is provided in the search path.
141  *
142  *	Another data structure maintained by this module is an mtime
143  *	cache used when the searching of cached directories fails to find
144  *	a file. In the past, Dir_FindFile would simply perform an access()
145  *	call in such a case to determine if the file could be found using
146  *	just the name given. When this hit, however, all that was gained
147  *	was the knowledge that the file existed. Given that an access() is
148  *	essentially a stat() without the copyout() call, and that the same
149  *	filesystem overhead would have to be incurred in Dir_MTime, it made
150  *	sense to replace the access() with a stat() and record the mtime
151  *	in a cache for when Dir_MTime was actually called.  */
152 
153 
154 /* several data structures exist to handle caching of directory stuff.
155  *
156  * There is a global hash of directory names (knownDirectories), and each
157  * read directory is kept there as one PathEntry instance. Such a structure
158  * only contains the file names.
159  *
160  * There is a global hash of timestamps (modification times), so care must
161  * be taken of giving the right file names to that structure.
162  *
163  * XXX A set of similar structure should exist at the Target level to properly
164  * take care of VPATH issues.
165  */
166 
167 
168 /* each directory is cached into a PathEntry structure. */
169 struct PathEntry {
170 	int refCount;		/* ref-counted, can participate to
171 				 * several paths */
172 	struct ohash files;	/* hash of name of files in the directory */
173 	char name[1];		/* directory name */
174 };
175 
176 /* PathEntry kept on knownDirectories */
177 static struct ohash_info dir_info = {
178 	offsetof(struct PathEntry, name), NULL, hash_calloc, hash_free,
179 	element_alloc
180 };
181 
182 static struct ohash   knownDirectories;	/* cache all open directories */
183 
184 
185 /* file names kept in a path entry */
186 static struct ohash_info file_info = {
187 	0, NULL, hash_calloc, hash_free, element_alloc
188 };
189 
190 
191 /* Global structure used to cache mtimes.  XXX We don't cache an mtime
192  * before a caller actually looks up for the given time, because of the
193  * possibility a caller might update the file and invalidate the cache
194  * entry, and we don't look up in this cache except as a last resort.
195  */
196 struct file_stamp {
197 	struct timespec mtime;		/* time stamp... */
198 	char name[1];			/* ...for that file.  */
199 };
200 
201 static struct ohash mtimes;
202 
203 
204 static struct ohash_info stamp_info = {
205 	offsetof(struct file_stamp, name), NULL, hash_calloc, hash_free,
206 	element_alloc
207 };
208 
209 
210 
211 static LIST   theDefaultPath;		/* main search path */
212 Lst	      defaultPath= &theDefaultPath;
213 struct PathEntry *dot; 			/* contents of current directory */
214 
215 
216 
217 /* add_file(path, name): add a file name to a path hash structure. */
218 static void add_file(struct PathEntry *, const char *);
219 /* n = find_file_hashi(p, name, end, hv): retrieve name in a path hash
220  * 	structure. */
221 static char *find_file_hashi(struct PathEntry *, const char *, const char *,
222     uint32_t);
223 
224 /* stamp = find_stampi(name, end): look for (name, end) in the global
225  *	cache. */
226 static struct file_stamp *find_stampi(const char *, const char *);
227 /* record_stamp(name, timestamp): record timestamp for name in the global
228  * 	cache. */
229 static void record_stamp(const char *, struct timespec);
230 
231 static bool read_directory(struct PathEntry *);
232 /* p = DirReaddiri(name, end): read an actual directory, caching results
233  * 	as we go.  */
234 static struct PathEntry *create_PathEntry(const char *, const char *);
235 /* Debugging: show a dir name in a path. */
236 static void DirPrintDir(void *);
237 
238 /***
239  *** timestamp handling
240  ***/
241 
242 static void
record_stamp(const char * file,struct timespec t)243 record_stamp(const char *file, struct timespec t)
244 {
245 	unsigned int slot;
246 	const char *end = NULL;
247 	struct file_stamp *n;
248 
249 	slot = ohash_qlookupi(&mtimes, file, &end);
250 	n = ohash_find(&mtimes, slot);
251 	if (n)
252 		n->mtime = t;
253 	else {
254 		n = ohash_create_entry(&stamp_info, file, &end);
255 		n->mtime = t;
256 		ohash_insert(&mtimes, slot, n);
257 	}
258 }
259 
260 static struct file_stamp *
find_stampi(const char * file,const char * efile)261 find_stampi(const char *file, const char *efile)
262 {
263 	return ohash_find(&mtimes, ohash_qlookupi(&mtimes, file, &efile));
264 }
265 
266 /***
267  *** PathEntry handling
268  ***/
269 
270 static void
add_file(struct PathEntry * p,const char * file)271 add_file(struct PathEntry *p, const char *file)
272 {
273 	unsigned int	slot;
274 	const char	*end = NULL;
275 	char		*n;
276 	struct ohash 	*h = &p->files;
277 
278 	slot = ohash_qlookupi(h, file, &end);
279 	n = ohash_find(h, slot);
280 	if (n == NULL) {
281 		n = ohash_create_entry(&file_info, file, &end);
282 		ohash_insert(h, slot, n);
283 	}
284 }
285 
286 static char *
find_file_hashi(struct PathEntry * p,const char * file,const char * efile,uint32_t hv)287 find_file_hashi(struct PathEntry *p, const char *file, const char *efile,
288     uint32_t hv)
289 {
290 	struct ohash 	*h = &p->files;
291 
292 	return ohash_find(h, ohash_lookup_interval(h, file, efile, hv));
293 }
294 
295 static bool
read_directory(struct PathEntry * p)296 read_directory(struct PathEntry *p)
297 {
298 	DIR *d;
299 	struct dirent *dp;
300 
301 	if (DEBUG(DIR)) {
302 		printf("Caching %s...", p->name);
303 		fflush(stdout);
304 	}
305 
306 	if ((d = opendir(p->name)) == NULL)
307 		return false;
308 
309 	ohash_init(&p->files, 4, &file_info);
310 
311 	while ((dp = readdir(d)) != NULL) {
312 		if (dp->d_name[0] == '.' &&
313 		    (dp->d_name[1] == '\0' ||
314 		    (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
315 			continue;
316 		add_file(p, dp->d_name);
317 	}
318 	(void)closedir(d);
319 	if (DEBUG(DIR))
320 		printf("done\n");
321 	return true;
322 }
323 
324 /* Read a directory, either from the disk, or from the cache.  */
325 static struct PathEntry *
create_PathEntry(const char * name,const char * ename)326 create_PathEntry(const char *name, const char *ename)
327 {
328 	struct PathEntry *p;
329 	unsigned int slot;
330 
331 	slot = ohash_qlookupi(&knownDirectories, name, &ename);
332 	p = ohash_find(&knownDirectories, slot);
333 
334 	if (p == NULL) {
335 		p = ohash_create_entry(&dir_info, name, &ename);
336 		p->refCount = 0;
337 		if (!read_directory(p)) {
338 			free(p);
339 			return NULL;
340 		}
341 		ohash_insert(&knownDirectories, slot, p);
342 	}
343 	p->refCount++;
344 	return p;
345 }
346 
347 char *
PathEntry_name(struct PathEntry * p)348 PathEntry_name(struct PathEntry *p)
349 {
350 	return p->name;
351 }
352 
353 /* Side Effects: cache the current directory */
354 void
Dir_Init(void)355 Dir_Init(void)
356 {
357 	char *dotname = ".";
358 
359 	Static_Lst_Init(defaultPath);
360 	ohash_init(&knownDirectories, 4, &dir_info);
361 	ohash_init(&mtimes, 4, &stamp_info);
362 
363 
364 	dot = create_PathEntry(dotname, dotname+1);
365 
366 	if (!dot)
367 		Fatal("Can't access current directory");
368 }
369 
370 /*-
371  *-----------------------------------------------------------------------
372  * Dir_MatchFilesi --
373  *	Given a pattern and a PathEntry structure, see if any files
374  *	match the pattern and add their names to the 'expansions' list if
375  *	any do. This is incomplete -- it doesn't take care of patterns like
376  *	src / *src / *.c properly (just *.c on any of the directories), but it
377  *	will do for now.
378  *-----------------------------------------------------------------------
379  */
380 void
Dir_MatchFilesi(const char * word,const char * eword,struct PathEntry * p,Lst expansions)381 Dir_MatchFilesi(const char *word, const char *eword, struct PathEntry *p,
382     Lst expansions)
383 {
384 	unsigned int search; 	/* Index into the directory's table */
385 	const char *entry; 	/* Current entry in the table */
386 
387 	for (entry = ohash_first(&p->files, &search); entry != NULL;
388 	     entry = ohash_next(&p->files, &search)) {
389 		/* See if the file matches the given pattern. We follow the UNIX
390 		 * convention that dot files will only be found if the pattern
391 		 * begins with a dot (the hashing scheme doesn't hash . or ..,
392 		 * so they won't match `.*'.  */
393 		if (*word != '.' && *entry == '.')
394 			continue;
395 		if (Str_Matchi(entry, strchr(entry, '\0'), word, eword))
396 			Lst_AtEnd(expansions,
397 			    p == dot  ? estrdup(entry) :
398 			    Str_concat(p->name, entry, '/'));
399 	}
400 }
401 
402 /*-
403  * Side Effects:
404  *	If the file is found in a directory which is not on the path
405  *	already (either 'name' is absolute or it is a relative path
406  *	[ dir1/.../dirn/file ] which exists below one of the directories
407  *	already on the search path), its directory is added to the end
408  *	of the path on the assumption that there will be more files in
409  *	that directory later on.
410  */
411 char *
Dir_FindFileComplexi(const char * name,const char * ename,Lst path,bool checkCurdirFirst)412 Dir_FindFileComplexi(const char *name, const char *ename, Lst path,
413     bool checkCurdirFirst)
414 {
415 	struct PathEntry *p;	/* current path member */
416 	char *p1;	/* pointer into p->name */
417 	const char *p2;	/* pointer into name */
418 	LstNode ln;	/* a list element */
419 	char *file;	/* the current filename to check */
420 	char *temp;	/* index into file */
421 	const char *basename;
422 	bool hasSlash;
423 	struct stat stb;/* Buffer for stat, if necessary */
424 	struct file_stamp *entry;
425 			/* Entry for mtimes table */
426 	uint32_t hv;	/* hash value for last component in file name */
427 	char *q;	/* Str_dupi(name, ename) */
428 
429 	/* Find the final component of the name and note whether name has a
430 	 * slash in it */
431 	basename = Str_rchri(name, ename, '/');
432 	if (basename) {
433 		hasSlash = true;
434 		basename++;
435 	} else {
436 		hasSlash = false;
437 		basename = name;
438 	}
439 
440 	hv = ohash_interval(basename, &ename);
441 
442 	if (DEBUG(DIR))
443 		printf("Searching for %s...", name);
444 	/* Unless checkCurDirFirst is false, we always look for
445 	 * the file in the current directory before anywhere else
446 	 * and we always return exactly what the caller specified. */
447 	if (checkCurdirFirst &&
448 	    (!hasSlash || (basename - name == 2 && *name == '.')) &&
449 	    find_file_hashi(dot, basename, ename, hv) != NULL) {
450 		if (DEBUG(DIR))
451 			printf("in '.'\n");
452 		return Str_dupi(name, ename);
453 	}
454 
455 	/* Then, we look through all the directories on path, seeking one
456 	 * containing the final component of name and whose final
457 	 * component(s) match name's initial component(s).
458 	 * If found, we concatenate the directory name and the
459 	 * final component and return the resulting string.  */
460 	for (ln = Lst_First(path); ln != NULL; ln = Lst_Adv(ln)) {
461 		p = Lst_Datum(ln);
462 		if (DEBUG(DIR))
463 			printf("%s...", p->name);
464 		if (find_file_hashi(p, basename, ename, hv) != NULL) {
465 			if (DEBUG(DIR))
466 				printf("here...");
467 			if (hasSlash) {
468 				/* If the name had a slash, its initial
469 				 * components and p's final components must
470 				 * match. This is false if a mismatch is
471 				 * encountered before all of the initial
472 				 * components have been checked (p2 > name at
473 				 * the end of the loop), or we matched only
474 				 * part of one of the components of p along
475 				 * with all the rest of them (*p1 != '/').  */
476 				p1 = p->name + strlen(p->name) - 1;
477 				p2 = basename - 2;
478 				while (p2 >= name && p1 >= p->name &&
479 				    *p1 == *p2) {
480 					p1--;
481 					p2--;
482 				}
483 				if (p2 >= name ||
484 				    (p1 >= p->name && *p1 != '/')) {
485 					if (DEBUG(DIR))
486 						printf("component mismatch -- continuing...");
487 					continue;
488 				}
489 			}
490 			file = Str_concati(p->name, strchr(p->name, '\0'), basename,
491 			    ename, '/');
492 			if (DEBUG(DIR))
493 				printf("returning %s\n", file);
494 			return file;
495 		} else if (hasSlash) {
496 			/* If the file has a leading path component and that
497 			 * component exactly matches the entire name of the
498 			 * current search directory, we assume the file
499 			 * doesn't exist and return NULL.  */
500 			for (p1 = p->name, p2 = name; *p1 && *p1 == *p2;
501 			    p1++, p2++)
502 				continue;
503 			if (*p1 == '\0' && p2 == basename - 1) {
504 				if (DEBUG(DIR))
505 					printf("has to be here but isn't -- returning NULL\n");
506 				return NULL;
507 			}
508 		}
509 	}
510 
511 	/* We didn't find the file on any existing member of the path.
512 	 * If the name doesn't contain a slash, end of story.
513 	 * If it does contain a slash, however, it could be in a subdirectory
514 	 * of one of the members of the search path. (eg., for path=/usr/include
515 	 * and name=sys/types.h, the above search fails to turn up types.h
516 	 * in /usr/include, even though /usr/include/sys/types.h exists).
517 	 *
518 	 * We only perform this look-up for non-absolute file names.
519 	 *
520 	 * Whenever we score a hit, we assume there will be more matches from
521 	 * that directory, and append all but the last component of the
522 	 * resulting name onto the search path. */
523 	if (!hasSlash) {
524 		if (DEBUG(DIR))
525 			printf("failed.\n");
526 		return NULL;
527 	}
528 
529 	if (*name != '/') {
530 		bool checkedDot = false;
531 
532 		if (DEBUG(DIR))
533 			printf("failed. Trying subdirectories...");
534 		for (ln = Lst_First(path); ln != NULL; ln = Lst_Adv(ln)) {
535 			p = Lst_Datum(ln);
536 			if (p != dot)
537 				file = Str_concati(p->name,
538 				    strchr(p->name, '\0'), name, ename, '/');
539 			else {
540 				/* Checking in dot -- DON'T put a leading
541 				* ./ on the thing.  */
542 				file = Str_dupi(name, ename);
543 				checkedDot = true;
544 			}
545 			if (DEBUG(DIR))
546 				printf("checking %s...", file);
547 
548 			if (stat(file, &stb) == 0) {
549 				struct timespec mtime;
550 
551 				ts_set_from_stat(stb, mtime);
552 				if (DEBUG(DIR))
553 					printf("got it.\n");
554 
555 				/* We've found another directory to search.
556 				 * We know there is a slash in 'file'. We
557 				 * call Dir_AddDiri to add the new directory
558 				 * onto the existing search path. Once that's
559 				 * done, we return the file name, knowing that
560 				 * should a file in this directory ever be
561 				 * referenced again in such a manner, we will
562 				 * find it without having to do numerous
563 				 * access calls.  */
564 				temp = strrchr(file, '/');
565 				Dir_AddDiri(path, file, temp);
566 
567 				/* Save the modification time so if it's
568 				* needed, we don't have to fetch it again.  */
569 				if (DEBUG(DIR))
570 					printf("Caching %s for %s\n",
571 					    time_to_string(&mtime), file);
572 				record_stamp(file, mtime);
573 				return file;
574 			} else
575 				free(file);
576 		}
577 
578 		if (DEBUG(DIR))
579 			printf("failed. ");
580 
581 		if (checkedDot) {
582 			/* Already checked by the given name, since . was in
583 			 * the path, so no point in proceeding...  */
584 			if (DEBUG(DIR))
585 				printf("Checked . already, returning NULL\n");
586 			return NULL;
587 		}
588 	}
589 
590 	/* Didn't find it that way, either. Last resort: look for the file
591 	 * in the global mtime cache, then on the disk.
592 	 * If this doesn't succeed, we finally return a NULL pointer.
593 	 *
594 	 * We cannot add this directory onto the search path because
595 	 * of this amusing case:
596 	 * $(INSTALLDIR)/$(FILE): $(FILE)
597 	 *
598 	 * $(FILE) exists in $(INSTALLDIR) but not in the current one.
599 	 * When searching for $(FILE), we will find it in $(INSTALLDIR)
600 	 * b/c we added it here. This is not good...  */
601 	q = Str_dupi(name, ename);
602 	if (DEBUG(DIR))
603 		printf("Looking for \"%s\"...", q);
604 
605 	entry = find_stampi(name, ename);
606 	if (entry != NULL) {
607 		if (DEBUG(DIR))
608 			printf("got it (in mtime cache)\n");
609 		return q;
610 	} else if (stat(q, &stb) == 0) {
611 		struct timespec mtime;
612 
613 		ts_set_from_stat(stb, mtime);
614 		if (DEBUG(DIR))
615 			printf("Caching %s for %s\n", time_to_string(&mtime),
616 			    q);
617 		record_stamp(q, mtime);
618 		return q;
619 	} else {
620 	    if (DEBUG(DIR))
621 		    printf("failed. Returning NULL\n");
622 	    free(q);
623 	    return NULL;
624 	}
625 }
626 
627 void
Dir_AddDiri(Lst path,const char * name,const char * ename)628 Dir_AddDiri(Lst path, const char *name, const char *ename)
629 {
630 	struct PathEntry	*p;
631 
632 	p = create_PathEntry(name, ename);
633 	if (p == NULL)
634 		return;
635 	if (p->refCount == 1)
636 		Lst_AtEnd(path, p);
637 	else if (!Lst_AddNew(path, p))
638 		return;
639 }
640 
641 void *
Dir_CopyDir(void * p)642 Dir_CopyDir(void *p)
643 {
644 	struct PathEntry *q = p;
645 	q->refCount++;
646 	return p;
647 }
648 
649 void
Dir_Destroy(void * pp)650 Dir_Destroy(void *pp)
651 {
652 	struct PathEntry *p = pp;
653 
654 	if (--p->refCount == 0) {
655 		ohash_remove(&knownDirectories,
656 		    ohash_qlookup(&knownDirectories, p->name));
657 		free_hash(&p->files);
658 		free(p);
659 	}
660 }
661 
662 /*-
663  *-----------------------------------------------------------------------
664  * Dir_Concat --
665  *	Concatenate two paths, adding the second to the end of the first.
666  *	Makes sure to avoid duplicates.
667  *
668  * Side Effects:
669  *	Reference counts for added dirs are upped.
670  *-----------------------------------------------------------------------
671  */
672 void
Dir_Concat(Lst path1,Lst path2)673 Dir_Concat(Lst path1, Lst path2)
674 {
675 	LstNode	ln;
676 	struct PathEntry *p;
677 
678 	for (ln = Lst_First(path2); ln != NULL; ln = Lst_Adv(ln)) {
679 		p = Lst_Datum(ln);
680 		if (Lst_AddNew(path1, p))
681 			p->refCount++;
682 	}
683 }
684 
685 static void
DirPrintDir(void * p)686 DirPrintDir(void *p)
687 {
688 	const struct PathEntry *q = p;
689 	printf("%s ", q->name);
690 }
691 
692 void
Dir_PrintPath(Lst path)693 Dir_PrintPath(Lst path)
694 {
695 	Lst_Every(path, DirPrintDir);
696 }
697 
698 struct timespec
Dir_MTime(GNode * gn)699 Dir_MTime(GNode *gn)
700 {
701 	char *fullName;
702 	struct stat stb;
703 	struct file_stamp *entry;
704 	unsigned int slot;
705 	struct timespec	  mtime;
706 
707 	if (gn->type & OP_PHONY)
708 		return gn->mtime;
709 
710 	if (gn->type & OP_ARCHV)
711 		return Arch_MTime(gn);
712 
713 	if (gn->path == NULL) {
714 		fullName = Dir_FindFile(gn->name, defaultPath);
715 		if (fullName == NULL)
716 			fullName = estrdup(gn->name);
717 	} else
718 		fullName = gn->path;
719 
720 	slot = ohash_qlookup(&mtimes, fullName);
721 	entry = ohash_find(&mtimes, slot);
722 	if (entry != NULL) {
723 		/* Only do this once -- the second time folks are checking to
724 		 * see if the file was actually updated, so we need to
725 		 * actually go to the file system.	*/
726 		if (DEBUG(DIR))
727 			printf("Using cached time %s for %s\n",
728 			    time_to_string(&entry->mtime), fullName);
729 		mtime = entry->mtime;
730 		free(entry);
731 		ohash_remove(&mtimes, slot);
732 	} else if (stat(fullName, &stb) == 0)
733 		ts_set_from_stat(stb, mtime);
734 	else {
735 		if (gn->type & OP_MEMBER) {
736 			if (fullName != gn->path)
737 				free(fullName);
738 			return Arch_MemMTime(gn);
739 		} else
740 			ts_set_out_of_date(mtime);
741 	}
742 	if (fullName && gn->path == NULL)
743 		gn->path = fullName;
744 
745 	gn->mtime = mtime;
746 	return gn->mtime;
747 }
748 
749