xref: /netbsd-src/usr.bin/make/dir.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: dir.c,v 1.12 1996/11/06 17:59:04 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
5  * Copyright (c) 1988, 1989 by Adam de Boor
6  * Copyright (c) 1989 by Berkeley Softworks
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * Adam de Boor.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)dir.c	8.2 (Berkeley) 1/2/94";
44 #else
45 static char rcsid[] = "$NetBSD: dir.c,v 1.12 1996/11/06 17:59:04 christos Exp $";
46 #endif
47 #endif /* not lint */
48 
49 /*-
50  * dir.c --
51  *	Directory searching using wildcards and/or normal names...
52  *	Used both for source wildcarding in the Makefile and for finding
53  *	implicit sources.
54  *
55  * The interface for this module is:
56  *	Dir_Init  	    Initialize the module.
57  *
58  *	Dir_End  	    Cleanup the module.
59  *
60  *	Dir_HasWildcards    Returns TRUE if the name given it needs to
61  *	    	  	    be wildcard-expanded.
62  *
63  *	Dir_Expand	    Given a pattern and a path, return a Lst of names
64  *	    	  	    which match the pattern on the search path.
65  *
66  *	Dir_FindFile	    Searches for a file on a given search path.
67  *	    	  	    If it exists, the entire path is returned.
68  *	    	  	    Otherwise NULL is returned.
69  *
70  *	Dir_MTime 	    Return the modification time of a node. The file
71  *	    	  	    is searched for along the default search path.
72  *	    	  	    The path and mtime fields of the node are filled
73  *	    	  	    in.
74  *
75  *	Dir_AddDir	    Add a directory to a search path.
76  *
77  *	Dir_MakeFlags	    Given a search path and a command flag, create
78  *	    	  	    a string with each of the directories in the path
79  *	    	  	    preceded by the command flag and all of them
80  *	    	  	    separated by a space.
81  *
82  *	Dir_Destroy	    Destroy an element of a search path. Frees up all
83  *	    	  	    things that can be freed for the element as long
84  *	    	  	    as the element is no longer referenced by any other
85  *	    	  	    search path.
86  *	Dir_ClearPath	    Resets a search path to the empty list.
87  *
88  * For debugging:
89  *	Dir_PrintDirectories	Print stats about the directory cache.
90  */
91 
92 #include <stdio.h>
93 #include <sys/types.h>
94 #include <dirent.h>
95 #include <sys/stat.h>
96 #include "make.h"
97 #include "hash.h"
98 #include "dir.h"
99 
100 /*
101  *	A search path consists of a Lst of Path structures. A Path structure
102  *	has in it the name of the directory and a hash table of all the files
103  *	in the directory. This is used to cut down on the number of system
104  *	calls necessary to find implicit dependents and their like. Since
105  *	these searches are made before any actions are taken, we need not
106  *	worry about the directory changing due to creation commands. If this
107  *	hampers the style of some makefiles, they must be changed.
108  *
109  *	A list of all previously-read directories is kept in the
110  *	openDirectories Lst. This list is checked first before a directory
111  *	is opened.
112  *
113  *	The need for the caching of whole directories is brought about by
114  *	the multi-level transformation code in suff.c, which tends to search
115  *	for far more files than regular make does. In the initial
116  *	implementation, the amount of time spent performing "stat" calls was
117  *	truly astronomical. The problem with hashing at the start is,
118  *	of course, that pmake doesn't then detect changes to these directories
119  *	during the course of the make. Three possibilities suggest themselves:
120  *
121  *	    1) just use stat to test for a file's existence. As mentioned
122  *	       above, this is very inefficient due to the number of checks
123  *	       engendered by the multi-level transformation code.
124  *	    2) use readdir() and company to search the directories, keeping
125  *	       them open between checks. I have tried this and while it
126  *	       didn't slow down the process too much, it could severely
127  *	       affect the amount of parallelism available as each directory
128  *	       open would take another file descriptor out of play for
129  *	       handling I/O for another job. Given that it is only recently
130  *	       that UNIX OS's have taken to allowing more than 20 or 32
131  *	       file descriptors for a process, this doesn't seem acceptable
132  *	       to me.
133  *	    3) record the mtime of the directory in the Path structure and
134  *	       verify the directory hasn't changed since the contents were
135  *	       hashed. This will catch the creation or deletion of files,
136  *	       but not the updating of files. However, since it is the
137  *	       creation and deletion that is the problem, this could be
138  *	       a good thing to do. Unfortunately, if the directory (say ".")
139  *	       were fairly large and changed fairly frequently, the constant
140  *	       rehashing could seriously degrade performance. It might be
141  *	       good in such cases to keep track of the number of rehashes
142  *	       and if the number goes over a (small) limit, resort to using
143  *	       stat in its place.
144  *
145  *	An additional thing to consider is that pmake is used primarily
146  *	to create C programs and until recently pcc-based compilers refused
147  *	to allow you to specify where the resulting object file should be
148  *	placed. This forced all objects to be created in the current
149  *	directory. This isn't meant as a full excuse, just an explanation of
150  *	some of the reasons for the caching used here.
151  *
152  *	One more note: the location of a target's file is only performed
153  *	on the downward traversal of the graph and then only for terminal
154  *	nodes in the graph. This could be construed as wrong in some cases,
155  *	but prevents inadvertent modification of files when the "installed"
156  *	directory for a file is provided in the search path.
157  *
158  *	Another data structure maintained by this module is an mtime
159  *	cache used when the searching of cached directories fails to find
160  *	a file. In the past, Dir_FindFile would simply perform an access()
161  *	call in such a case to determine if the file could be found using
162  *	just the name given. When this hit, however, all that was gained
163  *	was the knowledge that the file existed. Given that an access() is
164  *	essentially a stat() without the copyout() call, and that the same
165  *	filesystem overhead would have to be incurred in Dir_MTime, it made
166  *	sense to replace the access() with a stat() and record the mtime
167  *	in a cache for when Dir_MTime was actually called.
168  */
169 
170 Lst          dirSearchPath;	/* main search path */
171 
172 static Lst   openDirectories;	/* the list of all open directories */
173 
174 /*
175  * Variables for gathering statistics on the efficiency of the hashing
176  * mechanism.
177  */
178 static int    hits,	      /* Found in directory cache */
179 	      misses,	      /* Sad, but not evil misses */
180 	      nearmisses,     /* Found under search path */
181 	      bigmisses;      /* Sought by itself */
182 
183 static Path    	  *dot;	    /* contents of current directory */
184 static Hash_Table mtimes;   /* Results of doing a last-resort stat in
185 			     * Dir_FindFile -- if we have to go to the
186 			     * system to find the file, we might as well
187 			     * have its mtime on record. XXX: If this is done
188 			     * way early, there's a chance other rules will
189 			     * have already updated the file, in which case
190 			     * we'll update it again. Generally, there won't
191 			     * be two rules to update a single file, so this
192 			     * should be ok, but... */
193 
194 
195 static int DirFindName __P((ClientData, ClientData));
196 static int DirMatchFiles __P((char *, Path *, Lst));
197 static void DirExpandCurly __P((char *, char *, Lst, Lst));
198 static void DirExpandInt __P((char *, Lst, Lst));
199 static int DirPrintWord __P((ClientData, ClientData));
200 static int DirPrintDir __P((ClientData, ClientData));
201 
202 /*-
203  *-----------------------------------------------------------------------
204  * Dir_Init --
205  *	initialize things for this module
206  *
207  * Results:
208  *	none
209  *
210  * Side Effects:
211  *	some directories may be opened.
212  *-----------------------------------------------------------------------
213  */
214 void
215 Dir_Init ()
216 {
217     dirSearchPath = Lst_Init (FALSE);
218     openDirectories = Lst_Init (FALSE);
219     Hash_InitTable(&mtimes, 0);
220 
221     /*
222      * Since the Path structure is placed on both openDirectories and
223      * the path we give Dir_AddDir (which in this case is openDirectories),
224      * we need to remove "." from openDirectories and what better time to
225      * do it than when we have to fetch the thing anyway?
226      */
227     Dir_AddDir (openDirectories, ".");
228     dot = (Path *) Lst_DeQueue (openDirectories);
229 
230     /*
231      * We always need to have dot around, so we increment its reference count
232      * to make sure it's not destroyed.
233      */
234     dot->refCount += 1;
235 }
236 
237 /*-
238  *-----------------------------------------------------------------------
239  * Dir_End --
240  *	cleanup things for this module
241  *
242  * Results:
243  *	none
244  *
245  * Side Effects:
246  *	none
247  *-----------------------------------------------------------------------
248  */
249 void
250 Dir_End()
251 {
252     dot->refCount -= 1;
253     Dir_Destroy((ClientData) dot);
254     Dir_ClearPath(dirSearchPath);
255     Lst_Destroy(dirSearchPath, NOFREE);
256     Dir_ClearPath(openDirectories);
257     Lst_Destroy(openDirectories, NOFREE);
258     Hash_DeleteTable(&mtimes);
259 }
260 
261 /*-
262  *-----------------------------------------------------------------------
263  * DirFindName --
264  *	See if the Path structure describes the same directory as the
265  *	given one by comparing their names. Called from Dir_AddDir via
266  *	Lst_Find when searching the list of open directories.
267  *
268  * Results:
269  *	0 if it is the same. Non-zero otherwise
270  *
271  * Side Effects:
272  *	None
273  *-----------------------------------------------------------------------
274  */
275 static int
276 DirFindName (p, dname)
277     ClientData    p;	      /* Current name */
278     ClientData	  dname;      /* Desired name */
279 {
280     return (strcmp (((Path *)p)->name, (char *) dname));
281 }
282 
283 /*-
284  *-----------------------------------------------------------------------
285  * Dir_HasWildcards  --
286  *	see if the given name has any wildcard characters in it
287  *
288  * Results:
289  *	returns TRUE if the word should be expanded, FALSE otherwise
290  *
291  * Side Effects:
292  *	none
293  *-----------------------------------------------------------------------
294  */
295 Boolean
296 Dir_HasWildcards (name)
297     char          *name;	/* name to check */
298 {
299     register char *cp;
300 
301     for (cp = name; *cp; cp++) {
302 	switch(*cp) {
303 	case '{':
304 	case '[':
305 	case '?':
306 	case '*':
307 	    return (TRUE);
308 	}
309     }
310     return (FALSE);
311 }
312 
313 /*-
314  *-----------------------------------------------------------------------
315  * DirMatchFiles --
316  * 	Given a pattern and a Path structure, see if any files
317  *	match the pattern and add their names to the 'expansions' list if
318  *	any do. This is incomplete -- it doesn't take care of patterns like
319  *	src / *src / *.c properly (just *.c on any of the directories), but it
320  *	will do for now.
321  *
322  * Results:
323  *	Always returns 0
324  *
325  * Side Effects:
326  *	File names are added to the expansions lst. The directory will be
327  *	fully hashed when this is done.
328  *-----------------------------------------------------------------------
329  */
330 static int
331 DirMatchFiles (pattern, p, expansions)
332     char	  *pattern;   	/* Pattern to look for */
333     Path	  *p;         	/* Directory to search */
334     Lst	    	  expansions;	/* Place to store the results */
335 {
336     Hash_Search	  search;   	/* Index into the directory's table */
337     Hash_Entry	  *entry;   	/* Current entry in the table */
338     Boolean 	  isDot;    	/* TRUE if the directory being searched is . */
339 
340     isDot = (*p->name == '.' && p->name[1] == '\0');
341 
342     for (entry = Hash_EnumFirst(&p->files, &search);
343 	 entry != (Hash_Entry *)NULL;
344 	 entry = Hash_EnumNext(&search))
345     {
346 	/*
347 	 * See if the file matches the given pattern. Note we follow the UNIX
348 	 * convention that dot files will only be found if the pattern
349 	 * begins with a dot (note also that as a side effect of the hashing
350 	 * scheme, .* won't match . or .. since they aren't hashed).
351 	 */
352 	if (Str_Match(entry->name, pattern) &&
353 	    ((entry->name[0] != '.') ||
354 	     (pattern[0] == '.')))
355 	{
356 	    (void)Lst_AtEnd(expansions,
357 			    (isDot ? estrdup(entry->name) :
358 			     str_concat(p->name, entry->name,
359 					STR_ADDSLASH)));
360 	}
361     }
362     return (0);
363 }
364 
365 /*-
366  *-----------------------------------------------------------------------
367  * DirExpandCurly --
368  *	Expand curly braces like the C shell. Does this recursively.
369  *	Note the special case: if after the piece of the curly brace is
370  *	done there are no wildcard characters in the result, the result is
371  *	placed on the list WITHOUT CHECKING FOR ITS EXISTENCE.
372  *
373  * Results:
374  *	None.
375  *
376  * Side Effects:
377  *	The given list is filled with the expansions...
378  *
379  *-----------------------------------------------------------------------
380  */
381 static void
382 DirExpandCurly(word, brace, path, expansions)
383     char    	  *word;    	/* Entire word to expand */
384     char    	  *brace;   	/* First curly brace in it */
385     Lst	    	  path;	    	/* Search path to use */
386     Lst	    	  expansions;	/* Place to store the expansions */
387 {
388     char    	  *end;	    	/* Character after the closing brace */
389     char    	  *cp;	    	/* Current position in brace clause */
390     char    	  *start;   	/* Start of current piece of brace clause */
391     int	    	  bracelevel;	/* Number of braces we've seen. If we see a
392 				 * right brace when this is 0, we've hit the
393 				 * end of the clause. */
394     char    	  *file;    	/* Current expansion */
395     int	    	  otherLen; 	/* The length of the other pieces of the
396 				 * expansion (chars before and after the
397 				 * clause in 'word') */
398     char    	  *cp2;	    	/* Pointer for checking for wildcards in
399 				 * expansion before calling Dir_Expand */
400 
401     start = brace+1;
402 
403     /*
404      * Find the end of the brace clause first, being wary of nested brace
405      * clauses.
406      */
407     for (end = start, bracelevel = 0; *end != '\0'; end++) {
408 	if (*end == '{') {
409 	    bracelevel++;
410 	} else if ((*end == '}') && (bracelevel-- == 0)) {
411 	    break;
412 	}
413     }
414     if (*end == '\0') {
415 	Error("Unterminated {} clause \"%s\"", start);
416 	return;
417     } else {
418 	end++;
419     }
420     otherLen = brace - word + strlen(end);
421 
422     for (cp = start; cp < end; cp++) {
423 	/*
424 	 * Find the end of this piece of the clause.
425 	 */
426 	bracelevel = 0;
427 	while (*cp != ',') {
428 	    if (*cp == '{') {
429 		bracelevel++;
430 	    } else if ((*cp == '}') && (bracelevel-- <= 0)) {
431 		break;
432 	    }
433 	    cp++;
434 	}
435 	/*
436 	 * Allocate room for the combination and install the three pieces.
437 	 */
438 	file = emalloc(otherLen + cp - start + 1);
439 	if (brace != word) {
440 	    strncpy(file, word, brace-word);
441 	}
442 	if (cp != start) {
443 	    strncpy(&file[brace-word], start, cp-start);
444 	}
445 	strcpy(&file[(brace-word)+(cp-start)], end);
446 
447 	/*
448 	 * See if the result has any wildcards in it. If we find one, call
449 	 * Dir_Expand right away, telling it to place the result on our list
450 	 * of expansions.
451 	 */
452 	for (cp2 = file; *cp2 != '\0'; cp2++) {
453 	    switch(*cp2) {
454 	    case '*':
455 	    case '?':
456 	    case '{':
457 	    case '[':
458 		Dir_Expand(file, path, expansions);
459 		goto next;
460 	    }
461 	}
462 	if (*cp2 == '\0') {
463 	    /*
464 	     * Hit the end w/o finding any wildcards, so stick the expansion
465 	     * on the end of the list.
466 	     */
467 	    (void)Lst_AtEnd(expansions, file);
468 	} else {
469 	next:
470 	    free(file);
471 	}
472 	start = cp+1;
473     }
474 }
475 
476 
477 /*-
478  *-----------------------------------------------------------------------
479  * DirExpandInt --
480  *	Internal expand routine. Passes through the directories in the
481  *	path one by one, calling DirMatchFiles for each. NOTE: This still
482  *	doesn't handle patterns in directories...
483  *
484  * Results:
485  *	None.
486  *
487  * Side Effects:
488  *	Things are added to the expansions list.
489  *
490  *-----------------------------------------------------------------------
491  */
492 static void
493 DirExpandInt(word, path, expansions)
494     char    	  *word;    	/* Word to expand */
495     Lst	    	  path;	    	/* Path on which to look */
496     Lst	    	  expansions;	/* Place to store the result */
497 {
498     LstNode 	  ln;	    	/* Current node */
499     Path	  *p;	    	/* Directory in the node */
500 
501     if (Lst_Open(path) == SUCCESS) {
502 	while ((ln = Lst_Next(path)) != NILLNODE) {
503 	    p = (Path *)Lst_Datum(ln);
504 	    DirMatchFiles(word, p, expansions);
505 	}
506 	Lst_Close(path);
507     }
508 }
509 
510 /*-
511  *-----------------------------------------------------------------------
512  * DirPrintWord --
513  *	Print a word in the list of expansions. Callback for Dir_Expand
514  *	when DEBUG(DIR), via Lst_ForEach.
515  *
516  * Results:
517  *	=== 0
518  *
519  * Side Effects:
520  *	The passed word is printed, followed by a space.
521  *
522  *-----------------------------------------------------------------------
523  */
524 static int
525 DirPrintWord(word, dummy)
526     ClientData  word;
527     ClientData  dummy;
528 {
529     printf("%s ", (char *) word);
530 
531     return(dummy ? 0 : 0);
532 }
533 
534 /*-
535  *-----------------------------------------------------------------------
536  * Dir_Expand  --
537  *	Expand the given word into a list of words by globbing it looking
538  *	in the directories on the given search path.
539  *
540  * Results:
541  *	A list of words consisting of the files which exist along the search
542  *	path matching the given pattern.
543  *
544  * Side Effects:
545  *	Directories may be opened. Who knows?
546  *-----------------------------------------------------------------------
547  */
548 void
549 Dir_Expand (word, path, expansions)
550     char    *word;      /* the word to expand */
551     Lst     path;   	/* the list of directories in which to find
552 			 * the resulting files */
553     Lst	    expansions;	/* the list on which to place the results */
554 {
555     char    	  *cp;
556 
557     if (DEBUG(DIR)) {
558 	printf("expanding \"%s\"...", word);
559     }
560 
561     cp = strchr(word, '{');
562     if (cp) {
563 	DirExpandCurly(word, cp, path, expansions);
564     } else {
565 	cp = strchr(word, '/');
566 	if (cp) {
567 	    /*
568 	     * The thing has a directory component -- find the first wildcard
569 	     * in the string.
570 	     */
571 	    for (cp = word; *cp; cp++) {
572 		if (*cp == '?' || *cp == '[' || *cp == '*' || *cp == '{') {
573 		    break;
574 		}
575 	    }
576 	    if (*cp == '{') {
577 		/*
578 		 * This one will be fun.
579 		 */
580 		DirExpandCurly(word, cp, path, expansions);
581 		return;
582 	    } else if (*cp != '\0') {
583 		/*
584 		 * Back up to the start of the component
585 		 */
586 		char  *dirpath;
587 
588 		while (cp > word && *cp != '/') {
589 		    cp--;
590 		}
591 		if (cp != word) {
592 		    char sc;
593 		    /*
594 		     * If the glob isn't in the first component, try and find
595 		     * all the components up to the one with a wildcard.
596 		     */
597 		    sc = cp[1];
598 		    cp[1] = '\0';
599 		    dirpath = Dir_FindFile(word, path);
600 		    cp[1] = sc;
601 		    /*
602 		     * dirpath is null if can't find the leading component
603 		     * XXX: Dir_FindFile won't find internal components.
604 		     * i.e. if the path contains ../Etc/Object and we're
605 		     * looking for Etc, it won't be found. Ah well.
606 		     * Probably not important.
607 		     */
608 		    if (dirpath != (char *)NULL) {
609 			char *dp = &dirpath[strlen(dirpath) - 1];
610 			if (*dp == '/')
611 			    *dp = '\0';
612 			path = Lst_Init(FALSE);
613 			Dir_AddDir(path, dirpath);
614 			DirExpandInt(cp+1, path, expansions);
615 			Lst_Destroy(path, NOFREE);
616 		    }
617 		} else {
618 		    /*
619 		     * Start the search from the local directory
620 		     */
621 		    DirExpandInt(word, path, expansions);
622 		}
623 	    } else {
624 		/*
625 		 * Return the file -- this should never happen.
626 		 */
627 		DirExpandInt(word, path, expansions);
628 	    }
629 	} else {
630 	    /*
631 	     * First the files in dot
632 	     */
633 	    DirMatchFiles(word, dot, expansions);
634 
635 	    /*
636 	     * Then the files in every other directory on the path.
637 	     */
638 	    DirExpandInt(word, path, expansions);
639 	}
640     }
641     if (DEBUG(DIR)) {
642 	Lst_ForEach(expansions, DirPrintWord, (ClientData) 0);
643 	fputc('\n', stdout);
644     }
645 }
646 
647 /*-
648  *-----------------------------------------------------------------------
649  * Dir_FindFile  --
650  *	Find the file with the given name along the given search path.
651  *
652  * Results:
653  *	The path to the file or NULL. This path is guaranteed to be in a
654  *	different part of memory than name and so may be safely free'd.
655  *
656  * Side Effects:
657  *	If the file is found in a directory which is not on the path
658  *	already (either 'name' is absolute or it is a relative path
659  *	[ dir1/.../dirn/file ] which exists below one of the directories
660  *	already on the search path), its directory is added to the end
661  *	of the path on the assumption that there will be more files in
662  *	that directory later on. Sometimes this is true. Sometimes not.
663  *-----------------------------------------------------------------------
664  */
665 char *
666 Dir_FindFile (name, path)
667     char    	  *name;    /* the file to find */
668     Lst           path;	    /* the Lst of directories to search */
669 {
670     register char *p1;	    /* pointer into p->name */
671     register char *p2;	    /* pointer into name */
672     LstNode       ln;	    /* a list element */
673     register char *file;    /* the current filename to check */
674     register Path *p;	    /* current path member */
675     register char *cp;	    /* index of first slash, if any */
676     Boolean	  hasSlash; /* true if 'name' contains a / */
677     struct stat	  stb;	    /* Buffer for stat, if necessary */
678     Hash_Entry	  *entry;   /* Entry for mtimes table */
679 
680     /*
681      * Find the final component of the name and note whether it has a
682      * slash in it (the name, I mean)
683      */
684     cp = strrchr (name, '/');
685     if (cp) {
686 	hasSlash = TRUE;
687 	cp += 1;
688     } else {
689 	hasSlash = FALSE;
690 	cp = name;
691     }
692 
693     if (DEBUG(DIR)) {
694 	printf("Searching for %s...", name);
695     }
696     /*
697      * No matter what, we always look for the file in the current directory
698      * before anywhere else and we *do not* add the ./ to it if it exists.
699      * This is so there are no conflicts between what the user specifies
700      * (fish.c) and what pmake finds (./fish.c).
701      */
702     if ((!hasSlash || (cp - name == 2 && *name == '.')) &&
703 	(Hash_FindEntry (&dot->files, cp) != (Hash_Entry *)NULL)) {
704 	    if (DEBUG(DIR)) {
705 		printf("in '.'\n");
706 	    }
707 	    hits += 1;
708 	    dot->hits += 1;
709 	    return (estrdup (name));
710     }
711 
712     if (Lst_Open (path) == FAILURE) {
713 	if (DEBUG(DIR)) {
714 	    printf("couldn't open path, file not found\n");
715 	}
716 	misses += 1;
717 	return ((char *) NULL);
718     }
719 
720     /*
721      * We look through all the directories on the path seeking one which
722      * contains the final component of the given name and whose final
723      * component(s) match the name's initial component(s). If such a beast
724      * is found, we concatenate the directory name and the final component
725      * and return the resulting string. If we don't find any such thing,
726      * we go on to phase two...
727      */
728     while ((ln = Lst_Next (path)) != NILLNODE) {
729 	p = (Path *) Lst_Datum (ln);
730 	if (DEBUG(DIR)) {
731 	    printf("%s...", p->name);
732 	}
733 	if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
734 	    if (DEBUG(DIR)) {
735 		printf("here...");
736 	    }
737 	    if (hasSlash) {
738 		/*
739 		 * If the name had a slash, its initial components and p's
740 		 * final components must match. This is false if a mismatch
741 		 * is encountered before all of the initial components
742 		 * have been checked (p2 > name at the end of the loop), or
743 		 * we matched only part of one of the components of p
744 		 * along with all the rest of them (*p1 != '/').
745 		 */
746 		p1 = p->name + strlen (p->name) - 1;
747 		p2 = cp - 2;
748 		while (p2 >= name && p1 >= p->name && *p1 == *p2) {
749 		    p1 -= 1; p2 -= 1;
750 		}
751 		if (p2 >= name || (p1 >= p->name && *p1 != '/')) {
752 		    if (DEBUG(DIR)) {
753 			printf("component mismatch -- continuing...");
754 		    }
755 		    continue;
756 		}
757 	    }
758 	    file = str_concat (p->name, cp, STR_ADDSLASH);
759 	    if (DEBUG(DIR)) {
760 		printf("returning %s\n", file);
761 	    }
762 	    Lst_Close (path);
763 	    p->hits += 1;
764 	    hits += 1;
765 	    return (file);
766 	} else if (hasSlash) {
767 	    /*
768 	     * If the file has a leading path component and that component
769 	     * exactly matches the entire name of the current search
770 	     * directory, we assume the file doesn't exist and return NULL.
771 	     */
772 	    for (p1 = p->name, p2 = name; *p1 && *p1 == *p2; p1++, p2++) {
773 		continue;
774 	    }
775 	    if (*p1 == '\0' && p2 == cp - 1) {
776 		if (DEBUG(DIR)) {
777 		    printf("must be here but isn't -- returing NULL\n");
778 		}
779 		Lst_Close (path);
780 		return ((char *) NULL);
781 	    }
782 	}
783     }
784 
785     /*
786      * We didn't find the file on any existing members of the directory.
787      * If the name doesn't contain a slash, that means it doesn't exist.
788      * If it *does* contain a slash, however, there is still hope: it
789      * could be in a subdirectory of one of the members of the search
790      * path. (eg. /usr/include and sys/types.h. The above search would
791      * fail to turn up types.h in /usr/include, but it *is* in
792      * /usr/include/sys/types.h) If we find such a beast, we assume there
793      * will be more (what else can we assume?) and add all but the last
794      * component of the resulting name onto the search path (at the
795      * end). This phase is only performed if the file is *not* absolute.
796      */
797     if (!hasSlash) {
798 	if (DEBUG(DIR)) {
799 	    printf("failed.\n");
800 	}
801 	misses += 1;
802 	return ((char *) NULL);
803     }
804 
805     if (*name != '/') {
806 	Boolean	checkedDot = FALSE;
807 
808 	if (DEBUG(DIR)) {
809 	    printf("failed. Trying subdirectories...");
810 	}
811 	(void) Lst_Open (path);
812 	while ((ln = Lst_Next (path)) != NILLNODE) {
813 	    p = (Path *) Lst_Datum (ln);
814 	    if (p != dot) {
815 		file = str_concat (p->name, name, STR_ADDSLASH);
816 	    } else {
817 		/*
818 		 * Checking in dot -- DON'T put a leading ./ on the thing.
819 		 */
820 		file = estrdup(name);
821 		checkedDot = TRUE;
822 	    }
823 	    if (DEBUG(DIR)) {
824 		printf("checking %s...", file);
825 	    }
826 
827 
828 	    if (stat (file, &stb) == 0) {
829 		if (DEBUG(DIR)) {
830 		    printf("got it.\n");
831 		}
832 
833 		Lst_Close (path);
834 
835 		/*
836 		 * We've found another directory to search. We know there's
837 		 * a slash in 'file' because we put one there. We nuke it after
838 		 * finding it and call Dir_AddDir to add this new directory
839 		 * onto the existing search path. Once that's done, we restore
840 		 * the slash and triumphantly return the file name, knowing
841 		 * that should a file in this directory every be referenced
842 		 * again in such a manner, we will find it without having to do
843 		 * numerous numbers of access calls. Hurrah!
844 		 */
845 		cp = strrchr (file, '/');
846 		*cp = '\0';
847 		Dir_AddDir (path, file);
848 		*cp = '/';
849 
850 		/*
851 		 * Save the modification time so if it's needed, we don't have
852 		 * to fetch it again.
853 		 */
854 		if (DEBUG(DIR)) {
855 		    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
856 			    file);
857 		}
858 		entry = Hash_CreateEntry(&mtimes, (char *) file,
859 					 (Boolean *)NULL);
860 		Hash_SetValue(entry, (long)stb.st_mtime);
861 		nearmisses += 1;
862 		return (file);
863 	    } else {
864 		free (file);
865 	    }
866 	}
867 
868 	if (DEBUG(DIR)) {
869 	    printf("failed. ");
870 	}
871 	Lst_Close (path);
872 
873 	if (checkedDot) {
874 	    /*
875 	     * Already checked by the given name, since . was in the path,
876 	     * so no point in proceeding...
877 	     */
878 	    if (DEBUG(DIR)) {
879 		printf("Checked . already, returning NULL\n");
880 	    }
881 	    return(NULL);
882 	}
883     }
884 
885     /*
886      * Didn't find it that way, either. Sigh. Phase 3. Add its directory
887      * onto the search path in any case, just in case, then look for the
888      * thing in the hash table. If we find it, grand. We return a new
889      * copy of the name. Otherwise we sadly return a NULL pointer. Sigh.
890      * Note that if the directory holding the file doesn't exist, this will
891      * do an extra search of the final directory on the path. Unless something
892      * weird happens, this search won't succeed and life will be groovy.
893      *
894      * Sigh. We cannot add the directory onto the search path because
895      * of this amusing case:
896      * $(INSTALLDIR)/$(FILE): $(FILE)
897      *
898      * $(FILE) exists in $(INSTALLDIR) but not in the current one.
899      * When searching for $(FILE), we will find it in $(INSTALLDIR)
900      * b/c we added it here. This is not good...
901      */
902 #ifdef notdef
903     cp[-1] = '\0';
904     Dir_AddDir (path, name);
905     cp[-1] = '/';
906 
907     bigmisses += 1;
908     ln = Lst_Last (path);
909     if (ln == NILLNODE) {
910 	return ((char *) NULL);
911     } else {
912 	p = (Path *) Lst_Datum (ln);
913     }
914 
915     if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
916 	return (estrdup (name));
917     } else {
918 	return ((char *) NULL);
919     }
920 #else /* !notdef */
921     if (DEBUG(DIR)) {
922 	printf("Looking for \"%s\"...", name);
923     }
924 
925     bigmisses += 1;
926     entry = Hash_FindEntry(&mtimes, name);
927     if (entry != (Hash_Entry *)NULL) {
928 	if (DEBUG(DIR)) {
929 	    printf("got it (in mtime cache)\n");
930 	}
931 	return(estrdup(name));
932     } else if (stat (name, &stb) == 0) {
933 	entry = Hash_CreateEntry(&mtimes, name, (Boolean *)NULL);
934 	if (DEBUG(DIR)) {
935 	    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
936 		    name);
937 	}
938 	Hash_SetValue(entry, (long)stb.st_mtime);
939 	return (estrdup (name));
940     } else {
941 	if (DEBUG(DIR)) {
942 	    printf("failed. Returning NULL\n");
943 	}
944 	return ((char *)NULL);
945     }
946 #endif /* notdef */
947 }
948 
949 /*-
950  *-----------------------------------------------------------------------
951  * Dir_MTime  --
952  *	Find the modification time of the file described by gn along the
953  *	search path dirSearchPath.
954  *
955  * Results:
956  *	The modification time or 0 if it doesn't exist
957  *
958  * Side Effects:
959  *	The modification time is placed in the node's mtime slot.
960  *	If the node didn't have a path entry before, and Dir_FindFile
961  *	found one for it, the full name is placed in the path slot.
962  *-----------------------------------------------------------------------
963  */
964 int
965 Dir_MTime (gn)
966     GNode         *gn;	      /* the file whose modification time is
967 			       * desired */
968 {
969     char          *fullName;  /* the full pathname of name */
970     struct stat	  stb;	      /* buffer for finding the mod time */
971     Hash_Entry	  *entry;
972 
973     if (gn->type & OP_ARCHV) {
974 	return Arch_MTime (gn);
975     } else if (gn->path == (char *)NULL) {
976 	fullName = Dir_FindFile (gn->name, dirSearchPath);
977     } else {
978 	fullName = gn->path;
979     }
980 
981     if (fullName == (char *)NULL) {
982 	fullName = estrdup(gn->name);
983     }
984 
985     entry = Hash_FindEntry(&mtimes, fullName);
986     if (entry != (Hash_Entry *)NULL) {
987 	/*
988 	 * Only do this once -- the second time folks are checking to
989 	 * see if the file was actually updated, so we need to actually go
990 	 * to the file system.
991 	 */
992 	if (DEBUG(DIR)) {
993 	    printf("Using cached time %s for %s\n",
994 		    Targ_FmtTime((time_t)(long)Hash_GetValue(entry)), fullName);
995 	}
996 	stb.st_mtime = (time_t)(long)Hash_GetValue(entry);
997 	Hash_DeleteEntry(&mtimes, entry);
998     } else if (stat (fullName, &stb) < 0) {
999 	if (gn->type & OP_MEMBER) {
1000 	    if (fullName != gn->path)
1001 		free(fullName);
1002 	    return Arch_MemMTime (gn);
1003 	} else {
1004 	    stb.st_mtime = 0;
1005 	}
1006     }
1007     if (fullName && gn->path == (char *)NULL) {
1008 	gn->path = fullName;
1009     }
1010 
1011     gn->mtime = stb.st_mtime;
1012     return (gn->mtime);
1013 }
1014 
1015 /*-
1016  *-----------------------------------------------------------------------
1017  * Dir_AddDir --
1018  *	Add the given name to the end of the given path. The order of
1019  *	the arguments is backwards so ParseDoDependency can do a
1020  *	Lst_ForEach of its list of paths...
1021  *
1022  * Results:
1023  *	none
1024  *
1025  * Side Effects:
1026  *	A structure is added to the list and the directory is
1027  *	read and hashed.
1028  *-----------------------------------------------------------------------
1029  */
1030 void
1031 Dir_AddDir (path, name)
1032     Lst           path;	      /* the path to which the directory should be
1033 			       * added */
1034     char          *name;      /* the name of the directory to add */
1035 {
1036     LstNode       ln;	      /* node in case Path structure is found */
1037     register Path *p;	      /* pointer to new Path structure */
1038     DIR     	  *d;	      /* for reading directory */
1039     register struct dirent *dp; /* entry in directory */
1040 
1041     ln = Lst_Find (openDirectories, (ClientData)name, DirFindName);
1042     if (ln != NILLNODE) {
1043 	p = (Path *)Lst_Datum (ln);
1044 	if (Lst_Member(path, (ClientData)p) == NILLNODE) {
1045 	    p->refCount += 1;
1046 	    (void)Lst_AtEnd (path, (ClientData)p);
1047 	}
1048     } else {
1049 	if (DEBUG(DIR)) {
1050 	    printf("Caching %s...", name);
1051 	    fflush(stdout);
1052 	}
1053 
1054 	if ((d = opendir (name)) != (DIR *) NULL) {
1055 	    p = (Path *) emalloc (sizeof (Path));
1056 	    p->name = estrdup (name);
1057 	    p->hits = 0;
1058 	    p->refCount = 1;
1059 	    Hash_InitTable (&p->files, -1);
1060 
1061 	    /*
1062 	     * Skip the first two entries -- these will *always* be . and ..
1063 	     */
1064 	    (void)readdir(d);
1065 	    (void)readdir(d);
1066 
1067 	    while ((dp = readdir (d)) != (struct dirent *) NULL) {
1068 #if defined(sun) && defined(d_ino) /* d_ino is a sunos4 #define for d_fileno */
1069 		/*
1070 		 * The sun directory library doesn't check for a 0 inode
1071 		 * (0-inode slots just take up space), so we have to do
1072 		 * it ourselves.
1073 		 */
1074 		if (dp->d_fileno == 0) {
1075 		    continue;
1076 		}
1077 #endif /* sun && d_ino */
1078 		(void)Hash_CreateEntry(&p->files, dp->d_name, (Boolean *)NULL);
1079 	    }
1080 	    (void) closedir (d);
1081 	    (void)Lst_AtEnd (openDirectories, (ClientData)p);
1082 	    (void)Lst_AtEnd (path, (ClientData)p);
1083 	}
1084 	if (DEBUG(DIR)) {
1085 	    printf("done\n");
1086 	}
1087     }
1088 }
1089 
1090 /*-
1091  *-----------------------------------------------------------------------
1092  * Dir_CopyDir --
1093  *	Callback function for duplicating a search path via Lst_Duplicate.
1094  *	Ups the reference count for the directory.
1095  *
1096  * Results:
1097  *	Returns the Path it was given.
1098  *
1099  * Side Effects:
1100  *	The refCount of the path is incremented.
1101  *
1102  *-----------------------------------------------------------------------
1103  */
1104 ClientData
1105 Dir_CopyDir(p)
1106     ClientData p;
1107 {
1108     ((Path *) p)->refCount += 1;
1109 
1110     return ((ClientData)p);
1111 }
1112 
1113 /*-
1114  *-----------------------------------------------------------------------
1115  * Dir_MakeFlags --
1116  *	Make a string by taking all the directories in the given search
1117  *	path and preceding them by the given flag. Used by the suffix
1118  *	module to create variables for compilers based on suffix search
1119  *	paths.
1120  *
1121  * Results:
1122  *	The string mentioned above. Note that there is no space between
1123  *	the given flag and each directory. The empty string is returned if
1124  *	Things don't go well.
1125  *
1126  * Side Effects:
1127  *	None
1128  *-----------------------------------------------------------------------
1129  */
1130 char *
1131 Dir_MakeFlags (flag, path)
1132     char	  *flag;  /* flag which should precede each directory */
1133     Lst	    	  path;	  /* list of directories */
1134 {
1135     char	  *str;	  /* the string which will be returned */
1136     char	  *tstr;  /* the current directory preceded by 'flag' */
1137     LstNode	  ln;	  /* the node of the current directory */
1138     Path	  *p;	  /* the structure describing the current directory */
1139 
1140     str = estrdup ("");
1141 
1142     if (Lst_Open (path) == SUCCESS) {
1143 	while ((ln = Lst_Next (path)) != NILLNODE) {
1144 	    p = (Path *) Lst_Datum (ln);
1145 	    tstr = str_concat (flag, p->name, 0);
1146 	    str = str_concat (str, tstr, STR_ADDSPACE | STR_DOFREE);
1147 	}
1148 	Lst_Close (path);
1149     }
1150 
1151     return (str);
1152 }
1153 
1154 /*-
1155  *-----------------------------------------------------------------------
1156  * Dir_Destroy --
1157  *	Nuke a directory descriptor, if possible. Callback procedure
1158  *	for the suffixes module when destroying a search path.
1159  *
1160  * Results:
1161  *	None.
1162  *
1163  * Side Effects:
1164  *	If no other path references this directory (refCount == 0),
1165  *	the Path and all its data are freed.
1166  *
1167  *-----------------------------------------------------------------------
1168  */
1169 void
1170 Dir_Destroy (pp)
1171     ClientData 	  pp;	    /* The directory descriptor to nuke */
1172 {
1173     Path    	  *p = (Path *) pp;
1174     p->refCount -= 1;
1175 
1176     if (p->refCount == 0) {
1177 	LstNode	ln;
1178 
1179 	ln = Lst_Member (openDirectories, (ClientData)p);
1180 	(void) Lst_Remove (openDirectories, ln);
1181 
1182 	Hash_DeleteTable (&p->files);
1183 	free((Address)p->name);
1184 	free((Address)p);
1185     }
1186 }
1187 
1188 /*-
1189  *-----------------------------------------------------------------------
1190  * Dir_ClearPath --
1191  *	Clear out all elements of the given search path. This is different
1192  *	from destroying the list, notice.
1193  *
1194  * Results:
1195  *	None.
1196  *
1197  * Side Effects:
1198  *	The path is set to the empty list.
1199  *
1200  *-----------------------------------------------------------------------
1201  */
1202 void
1203 Dir_ClearPath(path)
1204     Lst	    path; 	/* Path to clear */
1205 {
1206     Path    *p;
1207     while (!Lst_IsEmpty(path)) {
1208 	p = (Path *)Lst_DeQueue(path);
1209 	Dir_Destroy((ClientData) p);
1210     }
1211 }
1212 
1213 
1214 /*-
1215  *-----------------------------------------------------------------------
1216  * Dir_Concat --
1217  *	Concatenate two paths, adding the second to the end of the first.
1218  *	Makes sure to avoid duplicates.
1219  *
1220  * Results:
1221  *	None
1222  *
1223  * Side Effects:
1224  *	Reference counts for added dirs are upped.
1225  *
1226  *-----------------------------------------------------------------------
1227  */
1228 void
1229 Dir_Concat(path1, path2)
1230     Lst	    path1;  	/* Dest */
1231     Lst	    path2;  	/* Source */
1232 {
1233     LstNode ln;
1234     Path    *p;
1235 
1236     for (ln = Lst_First(path2); ln != NILLNODE; ln = Lst_Succ(ln)) {
1237 	p = (Path *)Lst_Datum(ln);
1238 	if (Lst_Member(path1, (ClientData)p) == NILLNODE) {
1239 	    p->refCount += 1;
1240 	    (void)Lst_AtEnd(path1, (ClientData)p);
1241 	}
1242     }
1243 }
1244 
1245 /********** DEBUG INFO **********/
1246 void
1247 Dir_PrintDirectories()
1248 {
1249     LstNode	ln;
1250     Path	*p;
1251 
1252     printf ("#*** Directory Cache:\n");
1253     printf ("# Stats: %d hits %d misses %d near misses %d losers (%d%%)\n",
1254 	      hits, misses, nearmisses, bigmisses,
1255 	      (hits+bigmisses+nearmisses ?
1256 	       hits * 100 / (hits + bigmisses + nearmisses) : 0));
1257     printf ("# %-20s referenced\thits\n", "directory");
1258     if (Lst_Open (openDirectories) == SUCCESS) {
1259 	while ((ln = Lst_Next (openDirectories)) != NILLNODE) {
1260 	    p = (Path *) Lst_Datum (ln);
1261 	    printf ("# %-20s %10d\t%4d\n", p->name, p->refCount, p->hits);
1262 	}
1263 	Lst_Close (openDirectories);
1264     }
1265 }
1266 
1267 static int DirPrintDir (p, dummy)
1268     ClientData	p;
1269     ClientData	dummy;
1270 {
1271     printf ("%s ", ((Path *) p)->name);
1272     return (dummy ? 0 : 0);
1273 }
1274 
1275 void
1276 Dir_PrintPath (path)
1277     Lst	path;
1278 {
1279     Lst_ForEach (path, DirPrintDir, (ClientData)0);
1280 }
1281