[BACK]Return to dir.c CVS log [TXT][DIR] Up to [local] / src / usr.bin / make

File: [local] / src / usr.bin / make / dir.c (download)

Revision 1.69, Mon Sep 4 11:35:11 2023 UTC (8 months, 2 weeks ago) by espie
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, HEAD
Changes since 1.68: +1 -2 lines

GC old code that was originally implemented to facilitate adoption by
other BSDs, which never happened, so make things simpler for further
development.

Ditches config.h entirely since it gets reduced to 2 defines.

okay tb@

/*	$OpenBSD: dir.c,v 1.69 2023/09/04 11:35:11 espie Exp $ */
/*	$NetBSD: dir.c,v 1.14 1997/03/29 16:51:26 christos Exp $	*/

/*
 * Copyright (c) 1999 Marc Espie.
 *
 * Extensive code changes for the OpenBSD project.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
 * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
 * Copyright (c) 1988, 1989 by Adam de Boor
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/stat.h>
#include <dirent.h>
#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ohash.h>
#include "defines.h"
#include "dir.h"
#include "lst.h"
#include "memory.h"
#include "buf.h"
#include "gnode.h"
#include "arch.h"
#include "targ.h"
#include "error.h"
#include "str.h"
#include "timestamp.h"


/*	A search path consists of a Lst of PathEntry structures. A Path
 *	structure has in it the name of the directory and a hash table of all
 *	the files in the directory. This is used to cut down on the number of
 *	system calls necessary to find implicit dependents and their like.
 *	Since these searches are made before any actions are taken, we need not
 *	worry about the directory changing due to creation commands. If this
 *	hampers the style of some makefiles, they must be changed.
 *
 *	A list of all previously-read directories is kept in the
 *	knownDirectories cache.
 *
 *	The need for the caching of whole directories is brought about by
 *	the multi-level transformation code in suff.c, which tends to search
 *	for far more files than regular make does. In the initial
 *	implementation, the amount of time spent performing "stat" calls was
 *	truly astronomical. The problem with hashing at the start is,
 *	of course, that pmake doesn't then detect changes to these directories
 *	during the course of the make. Three possibilities suggest themselves:
 *
 *	    1) just use stat to test for a file's existence. As mentioned
 *	       above, this is very inefficient due to the number of checks
 *	       engendered by the multi-level transformation code.
 *	    2) use readdir() and company to search the directories, keeping
 *	       them open between checks. I have tried this and while it
 *	       didn't slow down the process too much, it could severely
 *	       affect the amount of parallelism available as each directory
 *	       open would take another file descriptor out of play for
 *	       handling I/O for another job. Given that it is only recently
 *	       that UNIX OS's have taken to allowing more than 20 or 32
 *	       file descriptors for a process, this doesn't seem acceptable
 *	       to me.
 *	    3) record the mtime of the directory in the PathEntry structure and
 *	       verify the directory hasn't changed since the contents were
 *	       hashed. This will catch the creation or deletion of files,
 *	       but not the updating of files. However, since it is the
 *	       creation and deletion that is the problem, this could be
 *	       a good thing to do. Unfortunately, if the directory (say ".")
 *	       were fairly large and changed fairly frequently, the constant
 *	       rehashing could seriously degrade performance. It might be
 *	       good in such cases to keep track of the number of rehashes
 *	       and if the number goes over a (small) limit, resort to using
 *	       stat in its place.
 *
 *	An additional thing to consider is that pmake is used primarily
 *	to create C programs and until recently pcc-based compilers refused
 *	to allow you to specify where the resulting object file should be
 *	placed. This forced all objects to be created in the current
 *	directory. This isn't meant as a full excuse, just an explanation of
 *	some of the reasons for the caching used here.
 *
 *	One more note: the location of a target's file is only performed
 *	on the downward traversal of the graph and then only for terminal
 *	nodes in the graph. This could be construed as wrong in some cases,
 *	but prevents inadvertent modification of files when the "installed"
 *	directory for a file is provided in the search path.
 *
 *	Another data structure maintained by this module is an mtime
 *	cache used when the searching of cached directories fails to find
 *	a file. In the past, Dir_FindFile would simply perform an access()
 *	call in such a case to determine if the file could be found using
 *	just the name given. When this hit, however, all that was gained
 *	was the knowledge that the file existed. Given that an access() is
 *	essentially a stat() without the copyout() call, and that the same
 *	filesystem overhead would have to be incurred in Dir_MTime, it made
 *	sense to replace the access() with a stat() and record the mtime
 *	in a cache for when Dir_MTime was actually called.  */


/* several data structures exist to handle caching of directory stuff.
 *
 * There is a global hash of directory names (knownDirectories), and each
 * read directory is kept there as one PathEntry instance. Such a structure
 * only contains the file names.
 *
 * There is a global hash of timestamps (modification times), so care must
 * be taken of giving the right file names to that structure.
 *
 * XXX A set of similar structure should exist at the Target level to properly
 * take care of VPATH issues.
 */


/* each directory is cached into a PathEntry structure. */
struct PathEntry {
	int refCount;		/* ref-counted, can participate to
				 * several paths */
	struct ohash files;	/* hash of name of files in the directory */
	char name[1];		/* directory name */
};

/* PathEntry kept on knownDirectories */
static struct ohash_info dir_info = {
	offsetof(struct PathEntry, name), NULL, hash_calloc, hash_free,
	element_alloc
};

static struct ohash   knownDirectories;	/* cache all open directories */


/* file names kept in a path entry */
static struct ohash_info file_info = {
	0, NULL, hash_calloc, hash_free, element_alloc
};


/* Global structure used to cache mtimes.  XXX We don't cache an mtime
 * before a caller actually looks up for the given time, because of the
 * possibility a caller might update the file and invalidate the cache
 * entry, and we don't look up in this cache except as a last resort.
 */
struct file_stamp {
	struct timespec mtime;		/* time stamp... */
	char name[1];			/* ...for that file.  */
};

static struct ohash mtimes;


static struct ohash_info stamp_info = {
	offsetof(struct file_stamp, name), NULL, hash_calloc, hash_free,
	element_alloc
};



static LIST   theDefaultPath;		/* main search path */
Lst	      defaultPath= &theDefaultPath;
struct PathEntry *dot; 			/* contents of current directory */



/* add_file(path, name): add a file name to a path hash structure. */
static void add_file(struct PathEntry *, const char *);
/* n = find_file_hashi(p, name, end, hv): retrieve name in a path hash
 * 	structure. */
static char *find_file_hashi(struct PathEntry *, const char *, const char *,
    uint32_t);

/* stamp = find_stampi(name, end): look for (name, end) in the global
 *	cache. */
static struct file_stamp *find_stampi(const char *, const char *);
/* record_stamp(name, timestamp): record timestamp for name in the global
 * 	cache. */
static void record_stamp(const char *, struct timespec);

static bool read_directory(struct PathEntry *);
/* p = DirReaddiri(name, end): read an actual directory, caching results
 * 	as we go.  */
static struct PathEntry *create_PathEntry(const char *, const char *);
/* Debugging: show a dir name in a path. */
static void DirPrintDir(void *);

/***
 *** timestamp handling
 ***/

static void
record_stamp(const char *file, struct timespec t)
{
	unsigned int slot;
	const char *end = NULL;
	struct file_stamp *n;

	slot = ohash_qlookupi(&mtimes, file, &end);
	n = ohash_find(&mtimes, slot);
	if (n)
		n->mtime = t;
	else {
		n = ohash_create_entry(&stamp_info, file, &end);
		n->mtime = t;
		ohash_insert(&mtimes, slot, n);
	}
}

static struct file_stamp *
find_stampi(const char *file, const char *efile)
{
	return ohash_find(&mtimes, ohash_qlookupi(&mtimes, file, &efile));
}

/***
 *** PathEntry handling
 ***/

static void
add_file(struct PathEntry *p, const char *file)
{
	unsigned int	slot;
	const char	*end = NULL;
	char		*n;
	struct ohash 	*h = &p->files;

	slot = ohash_qlookupi(h, file, &end);
	n = ohash_find(h, slot);
	if (n == NULL) {
		n = ohash_create_entry(&file_info, file, &end);
		ohash_insert(h, slot, n);
	}
}

static char *
find_file_hashi(struct PathEntry *p, const char *file, const char *efile,
    uint32_t hv)
{
	struct ohash 	*h = &p->files;

	return ohash_find(h, ohash_lookup_interval(h, file, efile, hv));
}

static bool
read_directory(struct PathEntry *p)
{
	DIR *d;
	struct dirent *dp;

	if (DEBUG(DIR)) {
		printf("Caching %s...", p->name);
		fflush(stdout);
	}

	if ((d = opendir(p->name)) == NULL)
		return false;

	ohash_init(&p->files, 4, &file_info);

	while ((dp = readdir(d)) != NULL) {
		if (dp->d_name[0] == '.' &&
		    (dp->d_name[1] == '\0' ||
		    (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
			continue;
		add_file(p, dp->d_name);
	}
	(void)closedir(d);
	if (DEBUG(DIR))
		printf("done\n");
	return true;
}

/* Read a directory, either from the disk, or from the cache.  */
static struct PathEntry *
create_PathEntry(const char *name, const char *ename)
{
	struct PathEntry *p;
	unsigned int slot;

	slot = ohash_qlookupi(&knownDirectories, name, &ename);
	p = ohash_find(&knownDirectories, slot);

	if (p == NULL) {
		p = ohash_create_entry(&dir_info, name, &ename);
		p->refCount = 0;
		if (!read_directory(p)) {
			free(p);
			return NULL;
		}
		ohash_insert(&knownDirectories, slot, p);
	}
	p->refCount++;
	return p;
}

char *
PathEntry_name(struct PathEntry *p)
{
	return p->name;
}

/* Side Effects: cache the current directory */
void
Dir_Init(void)
{
	char *dotname = ".";

	Static_Lst_Init(defaultPath);
	ohash_init(&knownDirectories, 4, &dir_info);
	ohash_init(&mtimes, 4, &stamp_info);


	dot = create_PathEntry(dotname, dotname+1);

	if (!dot)
		Fatal("Can't access current directory");
}

/*-
 *-----------------------------------------------------------------------
 * Dir_MatchFilesi --
 *	Given a pattern and a PathEntry structure, see if any files
 *	match the pattern and add their names to the 'expansions' list if
 *	any do. This is incomplete -- it doesn't take care of patterns like
 *	src / *src / *.c properly (just *.c on any of the directories), but it
 *	will do for now.
 *-----------------------------------------------------------------------
 */
void
Dir_MatchFilesi(const char *word, const char *eword, struct PathEntry *p,
    Lst expansions)
{
	unsigned int search; 	/* Index into the directory's table */
	const char *entry; 	/* Current entry in the table */

	for (entry = ohash_first(&p->files, &search); entry != NULL;
	     entry = ohash_next(&p->files, &search)) {
		/* See if the file matches the given pattern. We follow the UNIX
		 * convention that dot files will only be found if the pattern
		 * begins with a dot (the hashing scheme doesn't hash . or ..,
		 * so they won't match `.*'.  */
		if (*word != '.' && *entry == '.')
			continue;
		if (Str_Matchi(entry, strchr(entry, '\0'), word, eword))
			Lst_AtEnd(expansions,
			    p == dot  ? estrdup(entry) :
			    Str_concat(p->name, entry, '/'));
	}
}

/*-
 * Side Effects:
 *	If the file is found in a directory which is not on the path
 *	already (either 'name' is absolute or it is a relative path
 *	[ dir1/.../dirn/file ] which exists below one of the directories
 *	already on the search path), its directory is added to the end
 *	of the path on the assumption that there will be more files in
 *	that directory later on.
 */
char *
Dir_FindFileComplexi(const char *name, const char *ename, Lst path,
    bool checkCurdirFirst)
{
	struct PathEntry *p;	/* current path member */
	char *p1;	/* pointer into p->name */
	const char *p2;	/* pointer into name */
	LstNode ln;	/* a list element */
	char *file;	/* the current filename to check */
	char *temp;	/* index into file */
	const char *basename;
	bool hasSlash;
	struct stat stb;/* Buffer for stat, if necessary */
	struct file_stamp *entry;
			/* Entry for mtimes table */
	uint32_t hv;	/* hash value for last component in file name */
	char *q;	/* Str_dupi(name, ename) */

	/* Find the final component of the name and note whether name has a
	 * slash in it */
	basename = Str_rchri(name, ename, '/');
	if (basename) {
		hasSlash = true;
		basename++;
	} else {
		hasSlash = false;
		basename = name;
	}

	hv = ohash_interval(basename, &ename);

	if (DEBUG(DIR))
		printf("Searching for %s...", name);
	/* Unless checkCurDirFirst is false, we always look for
	 * the file in the current directory before anywhere else
	 * and we always return exactly what the caller specified. */
	if (checkCurdirFirst &&
	    (!hasSlash || (basename - name == 2 && *name == '.')) &&
	    find_file_hashi(dot, basename, ename, hv) != NULL) {
		if (DEBUG(DIR))
			printf("in '.'\n");
		return Str_dupi(name, ename);
	}

	/* Then, we look through all the directories on path, seeking one
	 * containing the final component of name and whose final
	 * component(s) match name's initial component(s).
	 * If found, we concatenate the directory name and the
	 * final component and return the resulting string.  */
	for (ln = Lst_First(path); ln != NULL; ln = Lst_Adv(ln)) {
		p = Lst_Datum(ln);
		if (DEBUG(DIR))
			printf("%s...", p->name);
		if (find_file_hashi(p, basename, ename, hv) != NULL) {
			if (DEBUG(DIR))
				printf("here...");
			if (hasSlash) {
				/* If the name had a slash, its initial
				 * components and p's final components must
				 * match. This is false if a mismatch is
				 * encountered before all of the initial
				 * components have been checked (p2 > name at
				 * the end of the loop), or we matched only
				 * part of one of the components of p along
				 * with all the rest of them (*p1 != '/').  */
				p1 = p->name + strlen(p->name) - 1;
				p2 = basename - 2;
				while (p2 >= name && p1 >= p->name &&
				    *p1 == *p2) {
					p1--;
					p2--;
				}
				if (p2 >= name ||
				    (p1 >= p->name && *p1 != '/')) {
					if (DEBUG(DIR))
						printf("component mismatch -- continuing...");
					continue;
				}
			}
			file = Str_concati(p->name, strchr(p->name, '\0'), basename,
			    ename, '/');
			if (DEBUG(DIR))
				printf("returning %s\n", file);
			return file;
		} else if (hasSlash) {
			/* If the file has a leading path component and that
			 * component exactly matches the entire name of the
			 * current search directory, we assume the file
			 * doesn't exist and return NULL.  */
			for (p1 = p->name, p2 = name; *p1 && *p1 == *p2;
			    p1++, p2++)
				continue;
			if (*p1 == '\0' && p2 == basename - 1) {
				if (DEBUG(DIR))
					printf("has to be here but isn't -- returning NULL\n");
				return NULL;
			}
		}
	}

	/* We didn't find the file on any existing member of the path.
	 * If the name doesn't contain a slash, end of story.
	 * If it does contain a slash, however, it could be in a subdirectory
	 * of one of the members of the search path. (eg., for path=/usr/include
	 * and name=sys/types.h, the above search fails to turn up types.h
	 * in /usr/include, even though /usr/include/sys/types.h exists).
	 *
	 * We only perform this look-up for non-absolute file names.
	 *
	 * Whenever we score a hit, we assume there will be more matches from
	 * that directory, and append all but the last component of the
	 * resulting name onto the search path. */
	if (!hasSlash) {
		if (DEBUG(DIR))
			printf("failed.\n");
		return NULL;
	}

	if (*name != '/') {
		bool checkedDot = false;

		if (DEBUG(DIR))
			printf("failed. Trying subdirectories...");
		for (ln = Lst_First(path); ln != NULL; ln = Lst_Adv(ln)) {
			p = Lst_Datum(ln);
			if (p != dot)
				file = Str_concati(p->name,
				    strchr(p->name, '\0'), name, ename, '/');
			else {
				/* Checking in dot -- DON'T put a leading
				* ./ on the thing.  */
				file = Str_dupi(name, ename);
				checkedDot = true;
			}
			if (DEBUG(DIR))
				printf("checking %s...", file);

			if (stat(file, &stb) == 0) {
				struct timespec mtime;

				ts_set_from_stat(stb, mtime);
				if (DEBUG(DIR))
					printf("got it.\n");

				/* We've found another directory to search.
				 * We know there is a slash in 'file'. We
				 * call Dir_AddDiri to add the new directory
				 * onto the existing search path. Once that's
				 * done, we return the file name, knowing that
				 * should a file in this directory ever be
				 * referenced again in such a manner, we will
				 * find it without having to do numerous
				 * access calls.  */
				temp = strrchr(file, '/');
				Dir_AddDiri(path, file, temp);

				/* Save the modification time so if it's
				* needed, we don't have to fetch it again.  */
				if (DEBUG(DIR))
					printf("Caching %s for %s\n",
					    time_to_string(&mtime), file);
				record_stamp(file, mtime);
				return file;
			} else
				free(file);
		}

		if (DEBUG(DIR))
			printf("failed. ");

		if (checkedDot) {
			/* Already checked by the given name, since . was in
			 * the path, so no point in proceeding...  */
			if (DEBUG(DIR))
				printf("Checked . already, returning NULL\n");
			return NULL;
		}
	}

	/* Didn't find it that way, either. Last resort: look for the file
	 * in the global mtime cache, then on the disk.
	 * If this doesn't succeed, we finally return a NULL pointer.
	 *
	 * We cannot add this directory onto the search path because
	 * of this amusing case:
	 * $(INSTALLDIR)/$(FILE): $(FILE)
	 *
	 * $(FILE) exists in $(INSTALLDIR) but not in the current one.
	 * When searching for $(FILE), we will find it in $(INSTALLDIR)
	 * b/c we added it here. This is not good...  */
	q = Str_dupi(name, ename);
	if (DEBUG(DIR))
		printf("Looking for \"%s\"...", q);

	entry = find_stampi(name, ename);
	if (entry != NULL) {
		if (DEBUG(DIR))
			printf("got it (in mtime cache)\n");
		return q;
	} else if (stat(q, &stb) == 0) {
		struct timespec mtime;

		ts_set_from_stat(stb, mtime);
		if (DEBUG(DIR))
			printf("Caching %s for %s\n", time_to_string(&mtime), 
			    q);
		record_stamp(q, mtime);
		return q;
	} else {
	    if (DEBUG(DIR))
		    printf("failed. Returning NULL\n");
	    free(q);
	    return NULL;
	}
}

void
Dir_AddDiri(Lst path, const char *name, const char *ename)
{
	struct PathEntry	*p;

	p = create_PathEntry(name, ename);
	if (p == NULL)
		return;
	if (p->refCount == 1)
		Lst_AtEnd(path, p);
	else if (!Lst_AddNew(path, p))
		return;
}

void *
Dir_CopyDir(void *p)
{
	struct PathEntry *q = p;
	q->refCount++;
	return p;
}

void
Dir_Destroy(void *pp)
{
	struct PathEntry *p = pp;

	if (--p->refCount == 0) {
		ohash_remove(&knownDirectories,
		    ohash_qlookup(&knownDirectories, p->name));
		free_hash(&p->files);
		free(p);
	}
}

/*-
 *-----------------------------------------------------------------------
 * Dir_Concat --
 *	Concatenate two paths, adding the second to the end of the first.
 *	Makes sure to avoid duplicates.
 *
 * Side Effects:
 *	Reference counts for added dirs are upped.
 *-----------------------------------------------------------------------
 */
void
Dir_Concat(Lst path1, Lst path2)
{
	LstNode	ln;
	struct PathEntry *p;

	for (ln = Lst_First(path2); ln != NULL; ln = Lst_Adv(ln)) {
		p = Lst_Datum(ln);
		if (Lst_AddNew(path1, p))
			p->refCount++;
	}
}

static void
DirPrintDir(void *p)
{
	const struct PathEntry *q = p;
	printf("%s ", q->name);
}

void
Dir_PrintPath(Lst path)
{
	Lst_Every(path, DirPrintDir);
}

struct timespec
Dir_MTime(GNode *gn)
{
	char *fullName;
	struct stat stb;
	struct file_stamp *entry;
	unsigned int slot;
	struct timespec	  mtime;

	if (gn->type & OP_PHONY)
		return gn->mtime;

	if (gn->type & OP_ARCHV)
		return Arch_MTime(gn);

	if (gn->path == NULL) {
		fullName = Dir_FindFile(gn->name, defaultPath);
		if (fullName == NULL)
			fullName = estrdup(gn->name);
	} else
		fullName = gn->path;

	slot = ohash_qlookup(&mtimes, fullName);
	entry = ohash_find(&mtimes, slot);
	if (entry != NULL) {
		/* Only do this once -- the second time folks are checking to
		 * see if the file was actually updated, so we need to
		 * actually go to the file system.	*/
		if (DEBUG(DIR))
			printf("Using cached time %s for %s\n",
			    time_to_string(&entry->mtime), fullName);
		mtime = entry->mtime;
		free(entry);
		ohash_remove(&mtimes, slot);
	} else if (stat(fullName, &stb) == 0)
		ts_set_from_stat(stb, mtime);
	else {
		if (gn->type & OP_MEMBER) {
			if (fullName != gn->path)
				free(fullName);
			return Arch_MemMTime(gn);
		} else
			ts_set_out_of_date(mtime);
	}
	if (fullName && gn->path == NULL)
		gn->path = fullName;

	gn->mtime = mtime;
	return gn->mtime;
}