xref: /netbsd-src/usr.bin/make/dir.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*
2  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
3  * Copyright (c) 1988, 1989 by Adam de Boor
4  * Copyright (c) 1989 by Berkeley Softworks
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Adam de Boor.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #ifndef lint
40 /* from: static char sccsid[] = "@(#)dir.c	5.6 (Berkeley) 12/28/90"; */
41 static char *rcsid = "$Id: dir.c,v 1.7 1994/12/24 16:54:24 cgd Exp $";
42 #endif /* not lint */
43 
44 /*-
45  * dir.c --
46  *	Directory searching using wildcards and/or normal names...
47  *	Used both for source wildcarding in the Makefile and for finding
48  *	implicit sources.
49  *
50  * The interface for this module is:
51  *	Dir_Init  	    Initialize the module.
52  *
53  *	Dir_End  	    Cleanup the module.
54  *
55  *	Dir_HasWildcards    Returns TRUE if the name given it needs to
56  *	    	  	    be wildcard-expanded.
57  *
58  *	Dir_Expand	    Given a pattern and a path, return a Lst of names
59  *	    	  	    which match the pattern on the search path.
60  *
61  *	Dir_FindFile	    Searches for a file on a given search path.
62  *	    	  	    If it exists, the entire path is returned.
63  *	    	  	    Otherwise NULL is returned.
64  *
65  *	Dir_MTime 	    Return the modification time of a node. The file
66  *	    	  	    is searched for along the default search path.
67  *	    	  	    The path and mtime fields of the node are filled
68  *	    	  	    in.
69  *
70  *	Dir_AddDir	    Add a directory to a search path.
71  *
72  *	Dir_MakeFlags	    Given a search path and a command flag, create
73  *	    	  	    a string with each of the directories in the path
74  *	    	  	    preceded by the command flag and all of them
75  *	    	  	    separated by a space.
76  *
77  *	Dir_Destroy	    Destroy an element of a search path. Frees up all
78  *	    	  	    things that can be freed for the element as long
79  *	    	  	    as the element is no longer referenced by any other
80  *	    	  	    search path.
81  *	Dir_ClearPath	    Resets a search path to the empty list.
82  *
83  * For debugging:
84  *	Dir_PrintDirectories	Print stats about the directory cache.
85  */
86 
87 #include <stdio.h>
88 #include <sys/types.h>
89 #include <dirent.h>
90 #include <sys/stat.h>
91 #include "make.h"
92 #include "hash.h"
93 #include "dir.h"
94 
95 /*
96  *	A search path consists of a Lst of Path structures. A Path structure
97  *	has in it the name of the directory and a hash table of all the files
98  *	in the directory. This is used to cut down on the number of system
99  *	calls necessary to find implicit dependents and their like. Since
100  *	these searches are made before any actions are taken, we need not
101  *	worry about the directory changing due to creation commands. If this
102  *	hampers the style of some makefiles, they must be changed.
103  *
104  *	A list of all previously-read directories is kept in the
105  *	openDirectories Lst. This list is checked first before a directory
106  *	is opened.
107  *
108  *	The need for the caching of whole directories is brought about by
109  *	the multi-level transformation code in suff.c, which tends to search
110  *	for far more files than regular make does. In the initial
111  *	implementation, the amount of time spent performing "stat" calls was
112  *	truly astronomical. The problem with hashing at the start is,
113  *	of course, that pmake doesn't then detect changes to these directories
114  *	during the course of the make. Three possibilities suggest themselves:
115  *
116  *	    1) just use stat to test for a file's existence. As mentioned
117  *	       above, this is very inefficient due to the number of checks
118  *	       engendered by the multi-level transformation code.
119  *	    2) use readdir() and company to search the directories, keeping
120  *	       them open between checks. I have tried this and while it
121  *	       didn't slow down the process too much, it could severely
122  *	       affect the amount of parallelism available as each directory
123  *	       open would take another file descriptor out of play for
124  *	       handling I/O for another job. Given that it is only recently
125  *	       that UNIX OS's have taken to allowing more than 20 or 32
126  *	       file descriptors for a process, this doesn't seem acceptable
127  *	       to me.
128  *	    3) record the mtime of the directory in the Path structure and
129  *	       verify the directory hasn't changed since the contents were
130  *	       hashed. This will catch the creation or deletion of files,
131  *	       but not the updating of files. However, since it is the
132  *	       creation and deletion that is the problem, this could be
133  *	       a good thing to do. Unfortunately, if the directory (say ".")
134  *	       were fairly large and changed fairly frequently, the constant
135  *	       rehashing could seriously degrade performance. It might be
136  *	       good in such cases to keep track of the number of rehashes
137  *	       and if the number goes over a (small) limit, resort to using
138  *	       stat in its place.
139  *
140  *	An additional thing to consider is that pmake is used primarily
141  *	to create C programs and until recently pcc-based compilers refused
142  *	to allow you to specify where the resulting object file should be
143  *	placed. This forced all objects to be created in the current
144  *	directory. This isn't meant as a full excuse, just an explanation of
145  *	some of the reasons for the caching used here.
146  *
147  *	One more note: the location of a target's file is only performed
148  *	on the downward traversal of the graph and then only for terminal
149  *	nodes in the graph. This could be construed as wrong in some cases,
150  *	but prevents inadvertent modification of files when the "installed"
151  *	directory for a file is provided in the search path.
152  *
153  *	Another data structure maintained by this module is an mtime
154  *	cache used when the searching of cached directories fails to find
155  *	a file. In the past, Dir_FindFile would simply perform an access()
156  *	call in such a case to determine if the file could be found using
157  *	just the name given. When this hit, however, all that was gained
158  *	was the knowledge that the file existed. Given that an access() is
159  *	essentially a stat() without the copyout() call, and that the same
160  *	filesystem overhead would have to be incurred in Dir_MTime, it made
161  *	sense to replace the access() with a stat() and record the mtime
162  *	in a cache for when Dir_MTime was actually called.
163  */
164 
165 Lst          dirSearchPath;	/* main search path */
166 
167 static Lst   openDirectories;	/* the list of all open directories */
168 
169 /*
170  * Variables for gathering statistics on the efficiency of the hashing
171  * mechanism.
172  */
173 static int    hits,	      /* Found in directory cache */
174 	      misses,	      /* Sad, but not evil misses */
175 	      nearmisses,     /* Found under search path */
176 	      bigmisses;      /* Sought by itself */
177 
178 static Path    	  *dot;	    /* contents of current directory */
179 static Hash_Table mtimes;   /* Results of doing a last-resort stat in
180 			     * Dir_FindFile -- if we have to go to the
181 			     * system to find the file, we might as well
182 			     * have its mtime on record. XXX: If this is done
183 			     * way early, there's a chance other rules will
184 			     * have already updated the file, in which case
185 			     * we'll update it again. Generally, there won't
186 			     * be two rules to update a single file, so this
187 			     * should be ok, but... */
188 
189 
190 static int DirFindName __P((ClientData, ClientData));
191 static int DirMatchFiles __P((char *, Path *, Lst));
192 static void DirExpandCurly __P((char *, char *, Lst, Lst));
193 static void DirExpandInt __P((char *, Lst, Lst));
194 static int DirPrintWord __P((ClientData, ClientData));
195 static int DirPrintDir __P((ClientData, ClientData));
196 
197 /*-
198  *-----------------------------------------------------------------------
199  * Dir_Init --
200  *	initialize things for this module
201  *
202  * Results:
203  *	none
204  *
205  * Side Effects:
206  *	some directories may be opened.
207  *-----------------------------------------------------------------------
208  */
209 void
210 Dir_Init ()
211 {
212     dirSearchPath = Lst_Init (FALSE);
213     openDirectories = Lst_Init (FALSE);
214     Hash_InitTable(&mtimes, 0);
215 
216     /*
217      * Since the Path structure is placed on both openDirectories and
218      * the path we give Dir_AddDir (which in this case is openDirectories),
219      * we need to remove "." from openDirectories and what better time to
220      * do it than when we have to fetch the thing anyway?
221      */
222     Dir_AddDir (openDirectories, ".");
223     dot = (Path *) Lst_DeQueue (openDirectories);
224 
225     /*
226      * We always need to have dot around, so we increment its reference count
227      * to make sure it's not destroyed.
228      */
229     dot->refCount += 1;
230 }
231 
232 /*-
233  *-----------------------------------------------------------------------
234  * Dir_End --
235  *	cleanup things for this module
236  *
237  * Results:
238  *	none
239  *
240  * Side Effects:
241  *	none
242  *-----------------------------------------------------------------------
243  */
244 void
245 Dir_End()
246 {
247     dot->refCount -= 1;
248     Dir_Destroy((ClientData) dot);
249     Dir_ClearPath(dirSearchPath);
250     Lst_Destroy(dirSearchPath, NOFREE);
251     Dir_ClearPath(openDirectories);
252     Lst_Destroy(openDirectories, NOFREE);
253     Hash_DeleteTable(&mtimes);
254 }
255 
256 /*-
257  *-----------------------------------------------------------------------
258  * DirFindName --
259  *	See if the Path structure describes the same directory as the
260  *	given one by comparing their names. Called from Dir_AddDir via
261  *	Lst_Find when searching the list of open directories.
262  *
263  * Results:
264  *	0 if it is the same. Non-zero otherwise
265  *
266  * Side Effects:
267  *	None
268  *-----------------------------------------------------------------------
269  */
270 static int
271 DirFindName (p, dname)
272     ClientData    p;	      /* Current name */
273     ClientData	  dname;      /* Desired name */
274 {
275     return (strcmp (((Path *)p)->name, (char *) dname));
276 }
277 
278 /*-
279  *-----------------------------------------------------------------------
280  * Dir_HasWildcards  --
281  *	see if the given name has any wildcard characters in it
282  *
283  * Results:
284  *	returns TRUE if the word should be expanded, FALSE otherwise
285  *
286  * Side Effects:
287  *	none
288  *-----------------------------------------------------------------------
289  */
290 Boolean
291 Dir_HasWildcards (name)
292     char          *name;	/* name to check */
293 {
294     register char *cp;
295 
296     for (cp = name; *cp; cp++) {
297 	switch(*cp) {
298 	case '{':
299 	case '[':
300 	case '?':
301 	case '*':
302 	    return (TRUE);
303 	}
304     }
305     return (FALSE);
306 }
307 
308 /*-
309  *-----------------------------------------------------------------------
310  * DirMatchFiles --
311  * 	Given a pattern and a Path structure, see if any files
312  *	match the pattern and add their names to the 'expansions' list if
313  *	any do. This is incomplete -- it doesn't take care of patterns like
314  *	src / *src / *.c properly (just *.c on any of the directories), but it
315  *	will do for now.
316  *
317  * Results:
318  *	Always returns 0
319  *
320  * Side Effects:
321  *	File names are added to the expansions lst. The directory will be
322  *	fully hashed when this is done.
323  *-----------------------------------------------------------------------
324  */
325 static int
326 DirMatchFiles (pattern, p, expansions)
327     char	  *pattern;   	/* Pattern to look for */
328     Path	  *p;         	/* Directory to search */
329     Lst	    	  expansions;	/* Place to store the results */
330 {
331     Hash_Search	  search;   	/* Index into the directory's table */
332     Hash_Entry	  *entry;   	/* Current entry in the table */
333     Boolean 	  isDot;    	/* TRUE if the directory being searched is . */
334 
335     isDot = (*p->name == '.' && p->name[1] == '\0');
336 
337     for (entry = Hash_EnumFirst(&p->files, &search);
338 	 entry != (Hash_Entry *)NULL;
339 	 entry = Hash_EnumNext(&search))
340     {
341 	/*
342 	 * See if the file matches the given pattern. Note we follow the UNIX
343 	 * convention that dot files will only be found if the pattern
344 	 * begins with a dot (note also that as a side effect of the hashing
345 	 * scheme, .* won't match . or .. since they aren't hashed).
346 	 */
347 	if (Str_Match(entry->name, pattern) &&
348 	    ((entry->name[0] != '.') ||
349 	     (pattern[0] == '.')))
350 	{
351 	    (void)Lst_AtEnd(expansions,
352 			    (isDot ? strdup(entry->name) :
353 			     str_concat(p->name, entry->name,
354 					STR_ADDSLASH)));
355 	}
356     }
357     return (0);
358 }
359 
360 /*-
361  *-----------------------------------------------------------------------
362  * DirExpandCurly --
363  *	Expand curly braces like the C shell. Does this recursively.
364  *	Note the special case: if after the piece of the curly brace is
365  *	done there are no wildcard characters in the result, the result is
366  *	placed on the list WITHOUT CHECKING FOR ITS EXISTENCE.
367  *
368  * Results:
369  *	None.
370  *
371  * Side Effects:
372  *	The given list is filled with the expansions...
373  *
374  *-----------------------------------------------------------------------
375  */
376 static void
377 DirExpandCurly(word, brace, path, expansions)
378     char    	  *word;    	/* Entire word to expand */
379     char    	  *brace;   	/* First curly brace in it */
380     Lst	    	  path;	    	/* Search path to use */
381     Lst	    	  expansions;	/* Place to store the expansions */
382 {
383     char    	  *end;	    	/* Character after the closing brace */
384     char    	  *cp;	    	/* Current position in brace clause */
385     char    	  *start;   	/* Start of current piece of brace clause */
386     int	    	  bracelevel;	/* Number of braces we've seen. If we see a
387 				 * right brace when this is 0, we've hit the
388 				 * end of the clause. */
389     char    	  *file;    	/* Current expansion */
390     int	    	  otherLen; 	/* The length of the other pieces of the
391 				 * expansion (chars before and after the
392 				 * clause in 'word') */
393     char    	  *cp2;	    	/* Pointer for checking for wildcards in
394 				 * expansion before calling Dir_Expand */
395 
396     start = brace+1;
397 
398     /*
399      * Find the end of the brace clause first, being wary of nested brace
400      * clauses.
401      */
402     for (end = start, bracelevel = 0; *end != '\0'; end++) {
403 	if (*end == '{') {
404 	    bracelevel++;
405 	} else if ((*end == '}') && (bracelevel-- == 0)) {
406 	    break;
407 	}
408     }
409     if (*end == '\0') {
410 	Error("Unterminated {} clause \"%s\"", start);
411 	return;
412     } else {
413 	end++;
414     }
415     otherLen = brace - word + strlen(end);
416 
417     for (cp = start; cp < end; cp++) {
418 	/*
419 	 * Find the end of this piece of the clause.
420 	 */
421 	bracelevel = 0;
422 	while (*cp != ',') {
423 	    if (*cp == '{') {
424 		bracelevel++;
425 	    } else if ((*cp == '}') && (bracelevel-- <= 0)) {
426 		break;
427 	    }
428 	    cp++;
429 	}
430 	/*
431 	 * Allocate room for the combination and install the three pieces.
432 	 */
433 	file = emalloc(otherLen + cp - start + 1);
434 	if (brace != word) {
435 	    strncpy(file, word, brace-word);
436 	}
437 	if (cp != start) {
438 	    strncpy(&file[brace-word], start, cp-start);
439 	}
440 	strcpy(&file[(brace-word)+(cp-start)], end);
441 
442 	/*
443 	 * See if the result has any wildcards in it. If we find one, call
444 	 * Dir_Expand right away, telling it to place the result on our list
445 	 * of expansions.
446 	 */
447 	for (cp2 = file; *cp2 != '\0'; cp2++) {
448 	    switch(*cp2) {
449 	    case '*':
450 	    case '?':
451 	    case '{':
452 	    case '[':
453 		Dir_Expand(file, path, expansions);
454 		goto next;
455 	    }
456 	}
457 	if (*cp2 == '\0') {
458 	    /*
459 	     * Hit the end w/o finding any wildcards, so stick the expansion
460 	     * on the end of the list.
461 	     */
462 	    (void)Lst_AtEnd(expansions, file);
463 	} else {
464 	next:
465 	    free(file);
466 	}
467 	start = cp+1;
468     }
469 }
470 
471 
472 /*-
473  *-----------------------------------------------------------------------
474  * DirExpandInt --
475  *	Internal expand routine. Passes through the directories in the
476  *	path one by one, calling DirMatchFiles for each. NOTE: This still
477  *	doesn't handle patterns in directories...
478  *
479  * Results:
480  *	None.
481  *
482  * Side Effects:
483  *	Things are added to the expansions list.
484  *
485  *-----------------------------------------------------------------------
486  */
487 static void
488 DirExpandInt(word, path, expansions)
489     char    	  *word;    	/* Word to expand */
490     Lst	    	  path;	    	/* Path on which to look */
491     Lst	    	  expansions;	/* Place to store the result */
492 {
493     LstNode 	  ln;	    	/* Current node */
494     Path	  *p;	    	/* Directory in the node */
495 
496     if (Lst_Open(path) == SUCCESS) {
497 	while ((ln = Lst_Next(path)) != NILLNODE) {
498 	    p = (Path *)Lst_Datum(ln);
499 	    DirMatchFiles(word, p, expansions);
500 	}
501 	Lst_Close(path);
502     }
503 }
504 
505 /*-
506  *-----------------------------------------------------------------------
507  * DirPrintWord --
508  *	Print a word in the list of expansions. Callback for Dir_Expand
509  *	when DEBUG(DIR), via Lst_ForEach.
510  *
511  * Results:
512  *	=== 0
513  *
514  * Side Effects:
515  *	The passed word is printed, followed by a space.
516  *
517  *-----------------------------------------------------------------------
518  */
519 static int
520 DirPrintWord(word, dummy)
521     ClientData  word;
522     ClientData  dummy;
523 {
524     printf("%s ", (char *) word);
525 
526     return(dummy ? 0 : 0);
527 }
528 
529 /*-
530  *-----------------------------------------------------------------------
531  * Dir_Expand  --
532  *	Expand the given word into a list of words by globbing it looking
533  *	in the directories on the given search path.
534  *
535  * Results:
536  *	A list of words consisting of the files which exist along the search
537  *	path matching the given pattern.
538  *
539  * Side Effects:
540  *	Directories may be opened. Who knows?
541  *-----------------------------------------------------------------------
542  */
543 void
544 Dir_Expand (word, path, expansions)
545     char    *word;      /* the word to expand */
546     Lst     path;   	/* the list of directories in which to find
547 			 * the resulting files */
548     Lst	    expansions;	/* the list on which to place the results */
549 {
550     char    	  *cp;
551 
552     if (DEBUG(DIR)) {
553 	printf("expanding \"%s\"...", word);
554     }
555 
556     cp = strchr(word, '{');
557     if (cp) {
558 	DirExpandCurly(word, cp, path, expansions);
559     } else {
560 	cp = strchr(word, '/');
561 	if (cp) {
562 	    /*
563 	     * The thing has a directory component -- find the first wildcard
564 	     * in the string.
565 	     */
566 	    for (cp = word; *cp; cp++) {
567 		if (*cp == '?' || *cp == '[' || *cp == '*' || *cp == '{') {
568 		    break;
569 		}
570 	    }
571 	    if (*cp == '{') {
572 		/*
573 		 * This one will be fun.
574 		 */
575 		DirExpandCurly(word, cp, path, expansions);
576 		return;
577 	    } else if (*cp != '\0') {
578 		/*
579 		 * Back up to the start of the component
580 		 */
581 		char  *dirpath;
582 
583 		while (cp > word && *cp != '/') {
584 		    cp--;
585 		}
586 		if (cp != word) {
587 		    char sc;
588 		    /*
589 		     * If the glob isn't in the first component, try and find
590 		     * all the components up to the one with a wildcard.
591 		     */
592 		    sc = cp[1];
593 		    cp[1] = '\0';
594 		    dirpath = Dir_FindFile(word, path);
595 		    cp[1] = sc;
596 		    /*
597 		     * dirpath is null if can't find the leading component
598 		     * XXX: Dir_FindFile won't find internal components.
599 		     * i.e. if the path contains ../Etc/Object and we're
600 		     * looking for Etc, it won't be found. Ah well.
601 		     * Probably not important.
602 		     */
603 		    if (dirpath != (char *)NULL) {
604 			char *dp = &dirpath[strlen(dirpath) - 1];
605 			if (*dp == '/')
606 			    *dp = '\0';
607 			path = Lst_Init(FALSE);
608 			Dir_AddDir(path, dirpath);
609 			DirExpandInt(cp+1, path, expansions);
610 			Lst_Destroy(path, NOFREE);
611 		    }
612 		} else {
613 		    /*
614 		     * Start the search from the local directory
615 		     */
616 		    DirExpandInt(word, path, expansions);
617 		}
618 	    } else {
619 		/*
620 		 * Return the file -- this should never happen.
621 		 */
622 		DirExpandInt(word, path, expansions);
623 	    }
624 	} else {
625 	    /*
626 	     * First the files in dot
627 	     */
628 	    DirMatchFiles(word, dot, expansions);
629 
630 	    /*
631 	     * Then the files in every other directory on the path.
632 	     */
633 	    DirExpandInt(word, path, expansions);
634 	}
635     }
636     if (DEBUG(DIR)) {
637 	Lst_ForEach(expansions, DirPrintWord, (ClientData) 0);
638 	fputc('\n', stdout);
639     }
640 }
641 
642 /*-
643  *-----------------------------------------------------------------------
644  * Dir_FindFile  --
645  *	Find the file with the given name along the given search path.
646  *
647  * Results:
648  *	The path to the file or NULL. This path is guaranteed to be in a
649  *	different part of memory than name and so may be safely free'd.
650  *
651  * Side Effects:
652  *	If the file is found in a directory which is not on the path
653  *	already (either 'name' is absolute or it is a relative path
654  *	[ dir1/.../dirn/file ] which exists below one of the directories
655  *	already on the search path), its directory is added to the end
656  *	of the path on the assumption that there will be more files in
657  *	that directory later on. Sometimes this is true. Sometimes not.
658  *-----------------------------------------------------------------------
659  */
660 char *
661 Dir_FindFile (name, path)
662     char    	  *name;    /* the file to find */
663     Lst           path;	    /* the Lst of directories to search */
664 {
665     register char *p1;	    /* pointer into p->name */
666     register char *p2;	    /* pointer into name */
667     LstNode       ln;	    /* a list element */
668     register char *file;    /* the current filename to check */
669     register Path *p;	    /* current path member */
670     register char *cp;	    /* index of first slash, if any */
671     Boolean	  hasSlash; /* true if 'name' contains a / */
672     struct stat	  stb;	    /* Buffer for stat, if necessary */
673     Hash_Entry	  *entry;   /* Entry for mtimes table */
674 
675     /*
676      * Find the final component of the name and note whether it has a
677      * slash in it (the name, I mean)
678      */
679     cp = strrchr (name, '/');
680     if (cp) {
681 	hasSlash = TRUE;
682 	cp += 1;
683     } else {
684 	hasSlash = FALSE;
685 	cp = name;
686     }
687 
688     if (DEBUG(DIR)) {
689 	printf("Searching for %s...", name);
690     }
691     /*
692      * No matter what, we always look for the file in the current directory
693      * before anywhere else and we *do not* add the ./ to it if it exists.
694      * This is so there are no conflicts between what the user specifies
695      * (fish.c) and what pmake finds (./fish.c).
696      */
697     if ((!hasSlash || (cp - name == 2 && *name == '.')) &&
698 	(Hash_FindEntry (&dot->files, cp) != (Hash_Entry *)NULL)) {
699 	    if (DEBUG(DIR)) {
700 		printf("in '.'\n");
701 	    }
702 	    hits += 1;
703 	    dot->hits += 1;
704 	    return (strdup (name));
705     }
706 
707     if (Lst_Open (path) == FAILURE) {
708 	if (DEBUG(DIR)) {
709 	    printf("couldn't open path, file not found\n");
710 	}
711 	misses += 1;
712 	return ((char *) NULL);
713     }
714 
715     /*
716      * We look through all the directories on the path seeking one which
717      * contains the final component of the given name and whose final
718      * component(s) match the name's initial component(s). If such a beast
719      * is found, we concatenate the directory name and the final component
720      * and return the resulting string. If we don't find any such thing,
721      * we go on to phase two...
722      */
723     while ((ln = Lst_Next (path)) != NILLNODE) {
724 	p = (Path *) Lst_Datum (ln);
725 	if (DEBUG(DIR)) {
726 	    printf("%s...", p->name);
727 	}
728 	if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
729 	    if (DEBUG(DIR)) {
730 		printf("here...");
731 	    }
732 	    if (hasSlash) {
733 		/*
734 		 * If the name had a slash, its initial components and p's
735 		 * final components must match. This is false if a mismatch
736 		 * is encountered before all of the initial components
737 		 * have been checked (p2 > name at the end of the loop), or
738 		 * we matched only part of one of the components of p
739 		 * along with all the rest of them (*p1 != '/').
740 		 */
741 		p1 = p->name + strlen (p->name) - 1;
742 		p2 = cp - 2;
743 		while (p2 >= name && p1 >= p->name && *p1 == *p2) {
744 		    p1 -= 1; p2 -= 1;
745 		}
746 		if (p2 >= name || (p1 >= p->name && *p1 != '/')) {
747 		    if (DEBUG(DIR)) {
748 			printf("component mismatch -- continuing...");
749 		    }
750 		    continue;
751 		}
752 	    }
753 	    file = str_concat (p->name, cp, STR_ADDSLASH);
754 	    if (DEBUG(DIR)) {
755 		printf("returning %s\n", file);
756 	    }
757 	    Lst_Close (path);
758 	    p->hits += 1;
759 	    hits += 1;
760 	    return (file);
761 	} else if (hasSlash) {
762 	    /*
763 	     * If the file has a leading path component and that component
764 	     * exactly matches the entire name of the current search
765 	     * directory, we assume the file doesn't exist and return NULL.
766 	     */
767 	    for (p1 = p->name, p2 = name; *p1 && *p1 == *p2; p1++, p2++) {
768 		continue;
769 	    }
770 	    if (*p1 == '\0' && p2 == cp - 1) {
771 		if (DEBUG(DIR)) {
772 		    printf("must be here but isn't -- returing NULL\n");
773 		}
774 		Lst_Close (path);
775 		return ((char *) NULL);
776 	    }
777 	}
778     }
779 
780     /*
781      * We didn't find the file on any existing members of the directory.
782      * If the name doesn't contain a slash, that means it doesn't exist.
783      * If it *does* contain a slash, however, there is still hope: it
784      * could be in a subdirectory of one of the members of the search
785      * path. (eg. /usr/include and sys/types.h. The above search would
786      * fail to turn up types.h in /usr/include, but it *is* in
787      * /usr/include/sys/types.h) If we find such a beast, we assume there
788      * will be more (what else can we assume?) and add all but the last
789      * component of the resulting name onto the search path (at the
790      * end). This phase is only performed if the file is *not* absolute.
791      */
792     if (!hasSlash) {
793 	if (DEBUG(DIR)) {
794 	    printf("failed.\n");
795 	}
796 	misses += 1;
797 	return ((char *) NULL);
798     }
799 
800     if (*name != '/') {
801 	Boolean	checkedDot = FALSE;
802 
803 	if (DEBUG(DIR)) {
804 	    printf("failed. Trying subdirectories...");
805 	}
806 	(void) Lst_Open (path);
807 	while ((ln = Lst_Next (path)) != NILLNODE) {
808 	    p = (Path *) Lst_Datum (ln);
809 	    if (p != dot) {
810 		file = str_concat (p->name, name, STR_ADDSLASH);
811 	    } else {
812 		/*
813 		 * Checking in dot -- DON'T put a leading ./ on the thing.
814 		 */
815 		file = strdup(name);
816 		checkedDot = TRUE;
817 	    }
818 	    if (DEBUG(DIR)) {
819 		printf("checking %s...", file);
820 	    }
821 
822 
823 	    if (stat (file, &stb) == 0) {
824 		if (DEBUG(DIR)) {
825 		    printf("got it.\n");
826 		}
827 
828 		Lst_Close (path);
829 
830 		/*
831 		 * We've found another directory to search. We know there's
832 		 * a slash in 'file' because we put one there. We nuke it after
833 		 * finding it and call Dir_AddDir to add this new directory
834 		 * onto the existing search path. Once that's done, we restore
835 		 * the slash and triumphantly return the file name, knowing
836 		 * that should a file in this directory every be referenced
837 		 * again in such a manner, we will find it without having to do
838 		 * numerous numbers of access calls. Hurrah!
839 		 */
840 		cp = strrchr (file, '/');
841 		*cp = '\0';
842 		Dir_AddDir (path, file);
843 		*cp = '/';
844 
845 		/*
846 		 * Save the modification time so if it's needed, we don't have
847 		 * to fetch it again.
848 		 */
849 		if (DEBUG(DIR)) {
850 		    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
851 			    file);
852 		}
853 		entry = Hash_CreateEntry(&mtimes, (char *) file,
854 					 (Boolean *)NULL);
855 		Hash_SetValue(entry, (long)stb.st_mtime);
856 		nearmisses += 1;
857 		return (file);
858 	    } else {
859 		free (file);
860 	    }
861 	}
862 
863 	if (DEBUG(DIR)) {
864 	    printf("failed. ");
865 	}
866 	Lst_Close (path);
867 
868 	if (checkedDot) {
869 	    /*
870 	     * Already checked by the given name, since . was in the path,
871 	     * so no point in proceeding...
872 	     */
873 	    if (DEBUG(DIR)) {
874 		printf("Checked . already, returning NULL\n");
875 	    }
876 	    return(NULL);
877 	}
878     }
879 
880     /*
881      * Didn't find it that way, either. Sigh. Phase 3. Add its directory
882      * onto the search path in any case, just in case, then look for the
883      * thing in the hash table. If we find it, grand. We return a new
884      * copy of the name. Otherwise we sadly return a NULL pointer. Sigh.
885      * Note that if the directory holding the file doesn't exist, this will
886      * do an extra search of the final directory on the path. Unless something
887      * weird happens, this search won't succeed and life will be groovy.
888      *
889      * Sigh. We cannot add the directory onto the search path because
890      * of this amusing case:
891      * $(INSTALLDIR)/$(FILE): $(FILE)
892      *
893      * $(FILE) exists in $(INSTALLDIR) but not in the current one.
894      * When searching for $(FILE), we will find it in $(INSTALLDIR)
895      * b/c we added it here. This is not good...
896      */
897 #ifdef notdef
898     cp[-1] = '\0';
899     Dir_AddDir (path, name);
900     cp[-1] = '/';
901 
902     bigmisses += 1;
903     ln = Lst_Last (path);
904     if (ln == NILLNODE) {
905 	return ((char *) NULL);
906     } else {
907 	p = (Path *) Lst_Datum (ln);
908     }
909 
910     if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
911 	return (strdup (name));
912     } else {
913 	return ((char *) NULL);
914     }
915 #else /* !notdef */
916     if (DEBUG(DIR)) {
917 	printf("Looking for \"%s\"...", name);
918     }
919 
920     bigmisses += 1;
921     entry = Hash_FindEntry(&mtimes, name);
922     if (entry != (Hash_Entry *)NULL) {
923 	if (DEBUG(DIR)) {
924 	    printf("got it (in mtime cache)\n");
925 	}
926 	return(strdup(name));
927     } else if (stat (name, &stb) == 0) {
928 	entry = Hash_CreateEntry(&mtimes, name, (Boolean *)NULL);
929 	if (DEBUG(DIR)) {
930 	    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
931 		    name);
932 	}
933 	Hash_SetValue(entry, (long)stb.st_mtime);
934 	return (strdup (name));
935     } else {
936 	if (DEBUG(DIR)) {
937 	    printf("failed. Returning NULL\n");
938 	}
939 	return ((char *)NULL);
940     }
941 #endif /* notdef */
942 }
943 
944 /*-
945  *-----------------------------------------------------------------------
946  * Dir_MTime  --
947  *	Find the modification time of the file described by gn along the
948  *	search path dirSearchPath.
949  *
950  * Results:
951  *	The modification time or 0 if it doesn't exist
952  *
953  * Side Effects:
954  *	The modification time is placed in the node's mtime slot.
955  *	If the node didn't have a path entry before, and Dir_FindFile
956  *	found one for it, the full name is placed in the path slot.
957  *-----------------------------------------------------------------------
958  */
959 int
960 Dir_MTime (gn)
961     GNode         *gn;	      /* the file whose modification time is
962 			       * desired */
963 {
964     char          *fullName;  /* the full pathname of name */
965     struct stat	  stb;	      /* buffer for finding the mod time */
966     Hash_Entry	  *entry;
967 
968     if (gn->type & OP_ARCHV) {
969 	return Arch_MTime (gn);
970     } else if (gn->path == (char *)NULL) {
971 	fullName = Dir_FindFile (gn->name, dirSearchPath);
972     } else {
973 	fullName = gn->path;
974     }
975 
976     if (fullName == (char *)NULL) {
977 	fullName = strdup(gn->name);
978     }
979 
980     entry = Hash_FindEntry(&mtimes, fullName);
981     if (entry != (Hash_Entry *)NULL) {
982 	/*
983 	 * Only do this once -- the second time folks are checking to
984 	 * see if the file was actually updated, so we need to actually go
985 	 * to the file system.
986 	 */
987 	if (DEBUG(DIR)) {
988 	    printf("Using cached time %s for %s\n",
989 		    Targ_FmtTime((time_t)(long)Hash_GetValue(entry)), fullName);
990 	}
991 	stb.st_mtime = (time_t)(long)Hash_GetValue(entry);
992 	Hash_DeleteEntry(&mtimes, entry);
993     } else if (stat (fullName, &stb) < 0) {
994 	if (gn->type & OP_MEMBER) {
995 	    if (fullName != gn->path)
996 		free(fullName);
997 	    return Arch_MemMTime (gn);
998 	} else {
999 	    stb.st_mtime = 0;
1000 	}
1001     }
1002     if (fullName && gn->path == (char *)NULL) {
1003 	gn->path = fullName;
1004     }
1005 
1006     gn->mtime = stb.st_mtime;
1007     return (gn->mtime);
1008 }
1009 
1010 /*-
1011  *-----------------------------------------------------------------------
1012  * Dir_AddDir --
1013  *	Add the given name to the end of the given path. The order of
1014  *	the arguments is backwards so ParseDoDependency can do a
1015  *	Lst_ForEach of its list of paths...
1016  *
1017  * Results:
1018  *	none
1019  *
1020  * Side Effects:
1021  *	A structure is added to the list and the directory is
1022  *	read and hashed.
1023  *-----------------------------------------------------------------------
1024  */
1025 void
1026 Dir_AddDir (path, name)
1027     Lst           path;	      /* the path to which the directory should be
1028 			       * added */
1029     char          *name;      /* the name of the directory to add */
1030 {
1031     LstNode       ln;	      /* node in case Path structure is found */
1032     register Path *p;	      /* pointer to new Path structure */
1033     DIR     	  *d;	      /* for reading directory */
1034     register struct dirent *dp; /* entry in directory */
1035 
1036     ln = Lst_Find (openDirectories, (ClientData)name, DirFindName);
1037     if (ln != NILLNODE) {
1038 	p = (Path *)Lst_Datum (ln);
1039 	if (Lst_Member(path, (ClientData)p) == NILLNODE) {
1040 	    p->refCount += 1;
1041 	    (void)Lst_AtEnd (path, (ClientData)p);
1042 	}
1043     } else {
1044 	if (DEBUG(DIR)) {
1045 	    printf("Caching %s...", name);
1046 	    fflush(stdout);
1047 	}
1048 
1049 	if ((d = opendir (name)) != (DIR *) NULL) {
1050 	    p = (Path *) emalloc (sizeof (Path));
1051 	    p->name = strdup (name);
1052 	    p->hits = 0;
1053 	    p->refCount = 1;
1054 	    Hash_InitTable (&p->files, -1);
1055 
1056 	    /*
1057 	     * Skip the first two entries -- these will *always* be . and ..
1058 	     */
1059 	    (void)readdir(d);
1060 	    (void)readdir(d);
1061 
1062 	    while ((dp = readdir (d)) != (struct dirent *) NULL) {
1063 #ifdef sun
1064 		/*
1065 		 * The sun directory library doesn't check for a 0 inode
1066 		 * (0-inode slots just take up space), so we have to do
1067 		 * it ourselves.
1068 		 */
1069 		if (dp->d_fileno == 0) {
1070 		    continue;
1071 		}
1072 #endif /* sun */
1073 		(void)Hash_CreateEntry(&p->files, dp->d_name, (Boolean *)NULL);
1074 	    }
1075 	    (void) closedir (d);
1076 	    (void)Lst_AtEnd (openDirectories, (ClientData)p);
1077 	    (void)Lst_AtEnd (path, (ClientData)p);
1078 	}
1079 	if (DEBUG(DIR)) {
1080 	    printf("done\n");
1081 	}
1082     }
1083 }
1084 
1085 /*-
1086  *-----------------------------------------------------------------------
1087  * Dir_CopyDir --
1088  *	Callback function for duplicating a search path via Lst_Duplicate.
1089  *	Ups the reference count for the directory.
1090  *
1091  * Results:
1092  *	Returns the Path it was given.
1093  *
1094  * Side Effects:
1095  *	The refCount of the path is incremented.
1096  *
1097  *-----------------------------------------------------------------------
1098  */
1099 ClientData
1100 Dir_CopyDir(p)
1101     ClientData p;
1102 {
1103     ((Path *) p)->refCount += 1;
1104 
1105     return ((ClientData)p);
1106 }
1107 
1108 /*-
1109  *-----------------------------------------------------------------------
1110  * Dir_MakeFlags --
1111  *	Make a string by taking all the directories in the given search
1112  *	path and preceding them by the given flag. Used by the suffix
1113  *	module to create variables for compilers based on suffix search
1114  *	paths.
1115  *
1116  * Results:
1117  *	The string mentioned above. Note that there is no space between
1118  *	the given flag and each directory. The empty string is returned if
1119  *	Things don't go well.
1120  *
1121  * Side Effects:
1122  *	None
1123  *-----------------------------------------------------------------------
1124  */
1125 char *
1126 Dir_MakeFlags (flag, path)
1127     char	  *flag;  /* flag which should precede each directory */
1128     Lst	    	  path;	  /* list of directories */
1129 {
1130     char	  *str;	  /* the string which will be returned */
1131     char	  *tstr;  /* the current directory preceded by 'flag' */
1132     LstNode	  ln;	  /* the node of the current directory */
1133     Path	  *p;	  /* the structure describing the current directory */
1134 
1135     str = strdup ("");
1136 
1137     if (Lst_Open (path) == SUCCESS) {
1138 	while ((ln = Lst_Next (path)) != NILLNODE) {
1139 	    p = (Path *) Lst_Datum (ln);
1140 	    tstr = str_concat (flag, p->name, 0);
1141 	    str = str_concat (str, tstr, STR_ADDSPACE | STR_DOFREE);
1142 	}
1143 	Lst_Close (path);
1144     }
1145 
1146     return (str);
1147 }
1148 
1149 /*-
1150  *-----------------------------------------------------------------------
1151  * Dir_Destroy --
1152  *	Nuke a directory descriptor, if possible. Callback procedure
1153  *	for the suffixes module when destroying a search path.
1154  *
1155  * Results:
1156  *	None.
1157  *
1158  * Side Effects:
1159  *	If no other path references this directory (refCount == 0),
1160  *	the Path and all its data are freed.
1161  *
1162  *-----------------------------------------------------------------------
1163  */
1164 void
1165 Dir_Destroy (pp)
1166     ClientData 	  pp;	    /* The directory descriptor to nuke */
1167 {
1168     Path    	  *p = (Path *) pp;
1169     p->refCount -= 1;
1170 
1171     if (p->refCount == 0) {
1172 	LstNode	ln;
1173 
1174 	ln = Lst_Member (openDirectories, (ClientData)p);
1175 	(void) Lst_Remove (openDirectories, ln);
1176 
1177 	Hash_DeleteTable (&p->files);
1178 	free((Address)p->name);
1179 	free((Address)p);
1180     }
1181 }
1182 
1183 /*-
1184  *-----------------------------------------------------------------------
1185  * Dir_ClearPath --
1186  *	Clear out all elements of the given search path. This is different
1187  *	from destroying the list, notice.
1188  *
1189  * Results:
1190  *	None.
1191  *
1192  * Side Effects:
1193  *	The path is set to the empty list.
1194  *
1195  *-----------------------------------------------------------------------
1196  */
1197 void
1198 Dir_ClearPath(path)
1199     Lst	    path; 	/* Path to clear */
1200 {
1201     Path    *p;
1202     while (!Lst_IsEmpty(path)) {
1203 	p = (Path *)Lst_DeQueue(path);
1204 	Dir_Destroy((ClientData) p);
1205     }
1206 }
1207 
1208 
1209 /*-
1210  *-----------------------------------------------------------------------
1211  * Dir_Concat --
1212  *	Concatenate two paths, adding the second to the end of the first.
1213  *	Makes sure to avoid duplicates.
1214  *
1215  * Results:
1216  *	None
1217  *
1218  * Side Effects:
1219  *	Reference counts for added dirs are upped.
1220  *
1221  *-----------------------------------------------------------------------
1222  */
1223 void
1224 Dir_Concat(path1, path2)
1225     Lst	    path1;  	/* Dest */
1226     Lst	    path2;  	/* Source */
1227 {
1228     LstNode ln;
1229     Path    *p;
1230 
1231     for (ln = Lst_First(path2); ln != NILLNODE; ln = Lst_Succ(ln)) {
1232 	p = (Path *)Lst_Datum(ln);
1233 	if (Lst_Member(path1, (ClientData)p) == NILLNODE) {
1234 	    p->refCount += 1;
1235 	    (void)Lst_AtEnd(path1, (ClientData)p);
1236 	}
1237     }
1238 }
1239 
1240 /********** DEBUG INFO **********/
1241 void
1242 Dir_PrintDirectories()
1243 {
1244     LstNode	ln;
1245     Path	*p;
1246 
1247     printf ("#*** Directory Cache:\n");
1248     printf ("# Stats: %d hits %d misses %d near misses %d losers (%d%%)\n",
1249 	      hits, misses, nearmisses, bigmisses,
1250 	      (hits+bigmisses+nearmisses ?
1251 	       hits * 100 / (hits + bigmisses + nearmisses) : 0));
1252     printf ("# %-20s referenced\thits\n", "directory");
1253     if (Lst_Open (openDirectories) == SUCCESS) {
1254 	while ((ln = Lst_Next (openDirectories)) != NILLNODE) {
1255 	    p = (Path *) Lst_Datum (ln);
1256 	    printf ("# %-20s %10d\t%4d\n", p->name, p->refCount, p->hits);
1257 	}
1258 	Lst_Close (openDirectories);
1259     }
1260 }
1261 
1262 static int DirPrintDir (p, dummy)
1263     ClientData	p;
1264     ClientData	dummy;
1265 {
1266     printf ("%s ", ((Path *) p)->name);
1267     return (dummy ? 0 : 0);
1268 }
1269 
1270 void
1271 Dir_PrintPath (path)
1272     Lst	path;
1273 {
1274     Lst_ForEach (path, DirPrintDir, (ClientData)0);
1275 }
1276