initial import of NetBSD tree

1 files changed, 1280 insertions, 0 deletions

diff --git a/usr.bin/make/dir.c b/usr.bin/make/dir.c
new file mode 100644
index 00000000000..83c22a02758
--- /dev/null
+++ b/usr.bin/make/dir.c
@@ -0,0 +1,1280 @@
+/*	$NetBSD: dir.c,v 1.8 1995/06/14 15:19:07 christos Exp $	*/
+
+/*
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)dir.c	5.6 (Berkeley) 12/28/90";
+#else
+static char rcsid[] = "$NetBSD: dir.c,v 1.8 1995/06/14 15:19:07 christos Exp $";
+#endif
+#endif /* not lint */
+
+/*-
+ * dir.c --
+ *	Directory searching using wildcards and/or normal names...
+ *	Used both for source wildcarding in the Makefile and for finding
+ *	implicit sources.
+ *
+ * The interface for this module is:
+ *	Dir_Init  	    Initialize the module.
+ *
+ *	Dir_End  	    Cleanup the module.
+ *
+ *	Dir_HasWildcards    Returns TRUE if the name given it needs to
+ *	    	  	    be wildcard-expanded.
+ *
+ *	Dir_Expand	    Given a pattern and a path, return a Lst of names
+ *	    	  	    which match the pattern on the search path.
+ *
+ *	Dir_FindFile	    Searches for a file on a given search path.
+ *	    	  	    If it exists, the entire path is returned.
+ *	    	  	    Otherwise NULL is returned.
+ *
+ *	Dir_MTime 	    Return the modification time of a node. The file
+ *	    	  	    is searched for along the default search path.
+ *	    	  	    The path and mtime fields of the node are filled
+ *	    	  	    in.
+ *
+ *	Dir_AddDir	    Add a directory to a search path.
+ *
+ *	Dir_MakeFlags	    Given a search path and a command flag, create
+ *	    	  	    a string with each of the directories in the path
+ *	    	  	    preceded by the command flag and all of them
+ *	    	  	    separated by a space.
+ *
+ *	Dir_Destroy	    Destroy an element of a search path. Frees up all
+ *	    	  	    things that can be freed for the element as long
+ *	    	  	    as the element is no longer referenced by any other
+ *	    	  	    search path.
+ *	Dir_ClearPath	    Resets a search path to the empty list.
+ *
+ * For debugging:
+ *	Dir_PrintDirectories	Print stats about the directory cache.
+ */
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include "make.h"
+#include "hash.h"
+#include "dir.h"
+
+/*
+ *	A search path consists of a Lst of Path 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
+ *	openDirectories Lst. This list is checked first before a directory
+ *	is opened.
+ *
+ *	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 Path 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.
+ */
+
+Lst          dirSearchPath;	/* main search path */
+
+static Lst   openDirectories;	/* the list of all open directories */
+
+/*
+ * Variables for gathering statistics on the efficiency of the hashing
+ * mechanism.
+ */
+static int    hits,	      /* Found in directory cache */
+	      misses,	      /* Sad, but not evil misses */
+	      nearmisses,     /* Found under search path */
+	      bigmisses;      /* Sought by itself */
+
+static Path    	  *dot;	    /* contents of current directory */
+static Hash_Table mtimes;   /* Results of doing a last-resort stat in
+			     * Dir_FindFile -- if we have to go to the
+			     * system to find the file, we might as well
+			     * have its mtime on record. XXX: If this is done
+			     * way early, there's a chance other rules will
+			     * have already updated the file, in which case
+			     * we'll update it again. Generally, there won't
+			     * be two rules to update a single file, so this
+			     * should be ok, but... */
+
+
+static int DirFindName __P((ClientData, ClientData));
+static int DirMatchFiles __P((char *, Path *, Lst));
+static void DirExpandCurly __P((char *, char *, Lst, Lst));
+static void DirExpandInt __P((char *, Lst, Lst));
+static int DirPrintWord __P((ClientData, ClientData));
+static int DirPrintDir __P((ClientData, ClientData));
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_Init --
+ *	initialize things for this module
+ *
+ * Results:
+ *	none
+ *
+ * Side Effects:
+ *	some directories may be opened.
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_Init ()
+{
+    dirSearchPath = Lst_Init (FALSE);
+    openDirectories = Lst_Init (FALSE);
+    Hash_InitTable(&mtimes, 0);
+    
+    /*
+     * Since the Path structure is placed on both openDirectories and
+     * the path we give Dir_AddDir (which in this case is openDirectories),
+     * we need to remove "." from openDirectories and what better time to
+     * do it than when we have to fetch the thing anyway?
+     */
+    Dir_AddDir (openDirectories, ".");
+    dot = (Path *) Lst_DeQueue (openDirectories);
+
+    /*
+     * We always need to have dot around, so we increment its reference count
+     * to make sure it's not destroyed.
+     */
+    dot->refCount += 1;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_End --
+ *	cleanup things for this module
+ *
+ * Results:
+ *	none
+ *
+ * Side Effects:
+ *	none
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_End()
+{
+    dot->refCount -= 1;
+    Dir_Destroy((ClientData) dot);
+    Dir_ClearPath(dirSearchPath);
+    Lst_Destroy(dirSearchPath, NOFREE);
+    Dir_ClearPath(openDirectories);
+    Lst_Destroy(openDirectories, NOFREE);
+    Hash_DeleteTable(&mtimes);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * DirFindName --
+ *	See if the Path structure describes the same directory as the
+ *	given one by comparing their names. Called from Dir_AddDir via
+ *	Lst_Find when searching the list of open directories.
+ *
+ * Results:
+ *	0 if it is the same. Non-zero otherwise
+ *
+ * Side Effects:
+ *	None
+ *-----------------------------------------------------------------------
+ */
+static int
+DirFindName (p, dname)
+    ClientData    p;	      /* Current name */
+    ClientData	  dname;      /* Desired name */
+{
+    return (strcmp (((Path *)p)->name, (char *) dname));
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_HasWildcards  --
+ *	see if the given name has any wildcard characters in it
+ *
+ * Results:
+ *	returns TRUE if the word should be expanded, FALSE otherwise
+ *
+ * Side Effects:
+ *	none
+ *-----------------------------------------------------------------------
+ */
+Boolean
+Dir_HasWildcards (name)
+    char          *name;	/* name to check */
+{
+    register char *cp;
+    
+    for (cp = name; *cp; cp++) {
+	switch(*cp) {
+	case '{':
+	case '[':
+	case '?':
+	case '*':
+	    return (TRUE);
+	}
+    }
+    return (FALSE);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * DirMatchFiles --
+ * 	Given a pattern and a Path 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.
+ *
+ * Results:
+ *	Always returns 0
+ *
+ * Side Effects:
+ *	File names are added to the expansions lst. The directory will be
+ *	fully hashed when this is done.
+ *-----------------------------------------------------------------------
+ */
+static int
+DirMatchFiles (pattern, p, expansions)
+    char	  *pattern;   	/* Pattern to look for */
+    Path	  *p;         	/* Directory to search */
+    Lst	    	  expansions;	/* Place to store the results */
+{
+    Hash_Search	  search;   	/* Index into the directory's table */	
+    Hash_Entry	  *entry;   	/* Current entry in the table */
+    Boolean 	  isDot;    	/* TRUE if the directory being searched is . */
+    
+    isDot = (*p->name == '.' && p->name[1] == '\0');
+    
+    for (entry = Hash_EnumFirst(&p->files, &search);
+	 entry != (Hash_Entry *)NULL;
+	 entry = Hash_EnumNext(&search))
+    {
+	/*
+	 * See if the file matches the given pattern. Note we follow the UNIX
+	 * convention that dot files will only be found if the pattern
+	 * begins with a dot (note also that as a side effect of the hashing
+	 * scheme, .* won't match . or .. since they aren't hashed).
+	 */
+	if (Str_Match(entry->name, pattern) &&
+	    ((entry->name[0] != '.') ||
+	     (pattern[0] == '.')))
+	{
+	    (void)Lst_AtEnd(expansions,
+			    (isDot ? strdup(entry->name) :
+			     str_concat(p->name, entry->name,
+					STR_ADDSLASH)));
+	}
+    }
+    return (0);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * DirExpandCurly --
+ *	Expand curly braces like the C shell. Does this recursively.
+ *	Note the special case: if after the piece of the curly brace is
+ *	done there are no wildcard characters in the result, the result is
+ *	placed on the list WITHOUT CHECKING FOR ITS EXISTENCE.
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	The given list is filled with the expansions...
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+DirExpandCurly(word, brace, path, expansions)
+    char    	  *word;    	/* Entire word to expand */
+    char    	  *brace;   	/* First curly brace in it */
+    Lst	    	  path;	    	/* Search path to use */
+    Lst	    	  expansions;	/* Place to store the expansions */
+{
+    char    	  *end;	    	/* Character after the closing brace */
+    char    	  *cp;	    	/* Current position in brace clause */
+    char    	  *start;   	/* Start of current piece of brace clause */
+    int	    	  bracelevel;	/* Number of braces we've seen. If we see a
+				 * right brace when this is 0, we've hit the
+				 * end of the clause. */
+    char    	  *file;    	/* Current expansion */
+    int	    	  otherLen; 	/* The length of the other pieces of the
+				 * expansion (chars before and after the
+				 * clause in 'word') */
+    char    	  *cp2;	    	/* Pointer for checking for wildcards in
+				 * expansion before calling Dir_Expand */
+
+    start = brace+1;
+
+    /*
+     * Find the end of the brace clause first, being wary of nested brace
+     * clauses.
+     */
+    for (end = start, bracelevel = 0; *end != '\0'; end++) {
+	if (*end == '{') {
+	    bracelevel++;
+	} else if ((*end == '}') && (bracelevel-- == 0)) {
+	    break;
+	}
+    }
+    if (*end == '\0') {
+	Error("Unterminated {} clause \"%s\"", start);
+	return;
+    } else {
+	end++;
+    }
+    otherLen = brace - word + strlen(end);
+
+    for (cp = start; cp < end; cp++) {
+	/*
+	 * Find the end of this piece of the clause.
+	 */
+	bracelevel = 0;
+	while (*cp != ',') {
+	    if (*cp == '{') {
+		bracelevel++;
+	    } else if ((*cp == '}') && (bracelevel-- <= 0)) {
+		break;
+	    }
+	    cp++;
+	}
+	/*
+	 * Allocate room for the combination and install the three pieces.
+	 */
+	file = emalloc(otherLen + cp - start + 1);
+	if (brace != word) {
+	    strncpy(file, word, brace-word);
+	}
+	if (cp != start) {
+	    strncpy(&file[brace-word], start, cp-start);
+	}
+	strcpy(&file[(brace-word)+(cp-start)], end);
+
+	/*
+	 * See if the result has any wildcards in it. If we find one, call
+	 * Dir_Expand right away, telling it to place the result on our list
+	 * of expansions.
+	 */
+	for (cp2 = file; *cp2 != '\0'; cp2++) {
+	    switch(*cp2) {
+	    case '*':
+	    case '?':
+	    case '{':
+	    case '[':
+		Dir_Expand(file, path, expansions);
+		goto next;
+	    }
+	}
+	if (*cp2 == '\0') {
+	    /*
+	     * Hit the end w/o finding any wildcards, so stick the expansion
+	     * on the end of the list.
+	     */
+	    (void)Lst_AtEnd(expansions, file);
+	} else {
+	next:
+	    free(file);
+	}
+	start = cp+1;
+    }
+}
+
+
+/*-
+ *-----------------------------------------------------------------------
+ * DirExpandInt --
+ *	Internal expand routine. Passes through the directories in the
+ *	path one by one, calling DirMatchFiles for each. NOTE: This still
+ *	doesn't handle patterns in directories...
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	Things are added to the expansions list.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+DirExpandInt(word, path, expansions)
+    char    	  *word;    	/* Word to expand */
+    Lst	    	  path;	    	/* Path on which to look */
+    Lst	    	  expansions;	/* Place to store the result */
+{
+    LstNode 	  ln;	    	/* Current node */
+    Path	  *p;	    	/* Directory in the node */
+
+    if (Lst_Open(path) == SUCCESS) {
+	while ((ln = Lst_Next(path)) != NILLNODE) {
+	    p = (Path *)Lst_Datum(ln);
+	    DirMatchFiles(word, p, expansions);
+	}
+	Lst_Close(path);
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * DirPrintWord --
+ *	Print a word in the list of expansions. Callback for Dir_Expand
+ *	when DEBUG(DIR), via Lst_ForEach.
+ *
+ * Results:
+ *	=== 0
+ *
+ * Side Effects:
+ *	The passed word is printed, followed by a space.
+ *
+ *-----------------------------------------------------------------------
+ */
+static int
+DirPrintWord(word, dummy)
+    ClientData  word;
+    ClientData  dummy;
+{
+    printf("%s ", (char *) word);
+
+    return(dummy ? 0 : 0);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_Expand  --
+ *	Expand the given word into a list of words by globbing it looking
+ *	in the directories on the given search path.
+ *
+ * Results:
+ *	A list of words consisting of the files which exist along the search
+ *	path matching the given pattern.
+ *
+ * Side Effects:
+ *	Directories may be opened. Who knows?
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_Expand (word, path, expansions)
+    char    *word;      /* the word to expand */
+    Lst     path;   	/* the list of directories in which to find
+			 * the resulting files */
+    Lst	    expansions;	/* the list on which to place the results */
+{
+    char    	  *cp;
+
+    if (DEBUG(DIR)) {
+	printf("expanding \"%s\"...", word);
+    }
+    
+    cp = strchr(word, '{');
+    if (cp) {
+	DirExpandCurly(word, cp, path, expansions);
+    } else {
+	cp = strchr(word, '/');
+	if (cp) {
+	    /*
+	     * The thing has a directory component -- find the first wildcard
+	     * in the string.
+	     */
+	    for (cp = word; *cp; cp++) {
+		if (*cp == '?' || *cp == '[' || *cp == '*' || *cp == '{') {
+		    break;
+		}
+	    }
+	    if (*cp == '{') {
+		/*
+		 * This one will be fun.
+		 */
+		DirExpandCurly(word, cp, path, expansions);
+		return;
+	    } else if (*cp != '\0') {
+		/*
+		 * Back up to the start of the component
+		 */
+		char  *dirpath;
+
+		while (cp > word && *cp != '/') {
+		    cp--;
+		}
+		if (cp != word) {
+		    char sc;
+		    /*
+		     * If the glob isn't in the first component, try and find
+		     * all the components up to the one with a wildcard.
+		     */
+		    sc = cp[1];
+		    cp[1] = '\0';
+		    dirpath = Dir_FindFile(word, path);
+		    cp[1] = sc;
+		    /*
+		     * dirpath is null if can't find the leading component
+		     * XXX: Dir_FindFile won't find internal components.
+		     * i.e. if the path contains ../Etc/Object and we're
+		     * looking for Etc, it won't be found. Ah well.
+		     * Probably not important.
+		     */
+		    if (dirpath != (char *)NULL) {
+			char *dp = &dirpath[strlen(dirpath) - 1];
+			if (*dp == '/')
+			    *dp = '\0';
+			path = Lst_Init(FALSE);
+			Dir_AddDir(path, dirpath);
+			DirExpandInt(cp+1, path, expansions);
+			Lst_Destroy(path, NOFREE);
+		    }
+		} else {
+		    /*
+		     * Start the search from the local directory
+		     */
+		    DirExpandInt(word, path, expansions);
+		}
+	    } else {
+		/*
+		 * Return the file -- this should never happen.
+		 */
+		DirExpandInt(word, path, expansions);
+	    }
+	} else {
+	    /*
+	     * First the files in dot
+	     */
+	    DirMatchFiles(word, dot, expansions);
+    
+	    /*
+	     * Then the files in every other directory on the path.
+	     */
+	    DirExpandInt(word, path, expansions);
+	}
+    }
+    if (DEBUG(DIR)) {
+	Lst_ForEach(expansions, DirPrintWord, (ClientData) 0);
+	fputc('\n', stdout);
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_FindFile  --
+ *	Find the file with the given name along the given search path.
+ *
+ * Results:
+ *	The path to the file or NULL. This path is guaranteed to be in a
+ *	different part of memory than name and so may be safely free'd.
+ *
+ * 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. Sometimes this is true. Sometimes not.
+ *-----------------------------------------------------------------------
+ */
+char *
+Dir_FindFile (name, path)
+    char    	  *name;    /* the file to find */
+    Lst           path;	    /* the Lst of directories to search */
+{
+    register char *p1;	    /* pointer into p->name */
+    register char *p2;	    /* pointer into name */
+    LstNode       ln;	    /* a list element */
+    register char *file;    /* the current filename to check */
+    register Path *p;	    /* current path member */
+    register char *cp;	    /* index of first slash, if any */
+    Boolean	  hasSlash; /* true if 'name' contains a / */
+    struct stat	  stb;	    /* Buffer for stat, if necessary */
+    Hash_Entry	  *entry;   /* Entry for mtimes table */
+    
+    /*
+     * Find the final component of the name and note whether it has a
+     * slash in it (the name, I mean)
+     */
+    cp = strrchr (name, '/');
+    if (cp) {
+	hasSlash = TRUE;
+	cp += 1;
+    } else {
+	hasSlash = FALSE;
+	cp = name;
+    }
+    
+    if (DEBUG(DIR)) {
+	printf("Searching for %s...", name);
+    }
+    /*
+     * No matter what, we always look for the file in the current directory
+     * before anywhere else and we *do not* add the ./ to it if it exists.
+     * This is so there are no conflicts between what the user specifies
+     * (fish.c) and what pmake finds (./fish.c).
+     */
+    if ((!hasSlash || (cp - name == 2 && *name == '.')) &&
+	(Hash_FindEntry (&dot->files, cp) != (Hash_Entry *)NULL)) {
+	    if (DEBUG(DIR)) {
+		printf("in '.'\n");
+	    }
+	    hits += 1;
+	    dot->hits += 1;
+	    return (strdup (name));
+    }
+    
+    if (Lst_Open (path) == FAILURE) {
+	if (DEBUG(DIR)) {
+	    printf("couldn't open path, file not found\n");
+	}
+	misses += 1;
+	return ((char *) NULL);
+    }
+    
+    /*
+     * We look through all the directories on the path seeking one which
+     * contains the final component of the given name and whose final
+     * component(s) match the name's initial component(s). If such a beast
+     * is found, we concatenate the directory name and the final component
+     * and return the resulting string. If we don't find any such thing,
+     * we go on to phase two...
+     */
+    while ((ln = Lst_Next (path)) != NILLNODE) {
+	p = (Path *) Lst_Datum (ln);
+	if (DEBUG(DIR)) {
+	    printf("%s...", p->name);
+	}
+	if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)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 = cp - 2;
+		while (p2 >= name && p1 >= p->name && *p1 == *p2) {
+		    p1 -= 1; p2 -= 1;
+		}
+		if (p2 >= name || (p1 >= p->name && *p1 != '/')) {
+		    if (DEBUG(DIR)) {
+			printf("component mismatch -- continuing...");
+		    }
+		    continue;
+		}
+	    }
+	    file = str_concat (p->name, cp, STR_ADDSLASH);
+	    if (DEBUG(DIR)) {
+		printf("returning %s\n", file);
+	    }
+	    Lst_Close (path);
+	    p->hits += 1;
+	    hits += 1;
+	    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 == cp - 1) {
+		if (DEBUG(DIR)) {
+		    printf("must be here but isn't -- returing NULL\n");
+		}
+		Lst_Close (path);
+		return ((char *) NULL);
+	    }
+	}
+    }
+    
+    /*
+     * We didn't find the file on any existing members of the directory.
+     * If the name doesn't contain a slash, that means it doesn't exist.
+     * If it *does* contain a slash, however, there is still hope: it
+     * could be in a subdirectory of one of the members of the search
+     * path. (eg. /usr/include and sys/types.h. The above search would
+     * fail to turn up types.h in /usr/include, but it *is* in
+     * /usr/include/sys/types.h) If we find such a beast, we assume there
+     * will be more (what else can we assume?) and add all but the last
+     * component of the resulting name onto the search path (at the
+     * end). This phase is only performed if the file is *not* absolute.
+     */
+    if (!hasSlash) {
+	if (DEBUG(DIR)) {
+	    printf("failed.\n");
+	}
+	misses += 1;
+	return ((char *) NULL);
+    }
+    
+    if (*name != '/') {
+	Boolean	checkedDot = FALSE;
+	
+	if (DEBUG(DIR)) {
+	    printf("failed. Trying subdirectories...");
+	}
+	(void) Lst_Open (path);
+	while ((ln = Lst_Next (path)) != NILLNODE) {
+	    p = (Path *) Lst_Datum (ln);
+	    if (p != dot) {
+		file = str_concat (p->name, name, STR_ADDSLASH);
+	    } else {
+		/*
+		 * Checking in dot -- DON'T put a leading ./ on the thing.
+		 */
+		file = strdup(name);
+		checkedDot = TRUE;
+	    }
+	    if (DEBUG(DIR)) {
+		printf("checking %s...", file);
+	    }
+	    
+		
+	    if (stat (file, &stb) == 0) {
+		if (DEBUG(DIR)) {
+		    printf("got it.\n");
+		}
+		
+		Lst_Close (path);
+		
+		/*
+		 * We've found another directory to search. We know there's
+		 * a slash in 'file' because we put one there. We nuke it after
+		 * finding it and call Dir_AddDir to add this new directory
+		 * onto the existing search path. Once that's done, we restore
+		 * the slash and triumphantly return the file name, knowing
+		 * that should a file in this directory every be referenced
+		 * again in such a manner, we will find it without having to do
+		 * numerous numbers of access calls. Hurrah!
+		 */
+		cp = strrchr (file, '/');
+		*cp = '\0';
+		Dir_AddDir (path, file);
+		*cp = '/';
+		
+		/*
+		 * 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", Targ_FmtTime(stb.st_mtime),
+			    file);
+		}
+		entry = Hash_CreateEntry(&mtimes, (char *) file,
+					 (Boolean *)NULL);
+		Hash_SetValue(entry, (long)stb.st_mtime);
+		nearmisses += 1;
+		return (file);
+	    } else {
+		free (file);
+	    }
+	}
+	
+	if (DEBUG(DIR)) {
+	    printf("failed. ");
+	}
+	Lst_Close (path);
+
+	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. Sigh. Phase 3. Add its directory
+     * onto the search path in any case, just in case, then look for the
+     * thing in the hash table. If we find it, grand. We return a new
+     * copy of the name. Otherwise we sadly return a NULL pointer. Sigh.
+     * Note that if the directory holding the file doesn't exist, this will
+     * do an extra search of the final directory on the path. Unless something
+     * weird happens, this search won't succeed and life will be groovy.
+     *
+     * Sigh. We cannot add the 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...
+     */
+#ifdef notdef
+    cp[-1] = '\0';
+    Dir_AddDir (path, name);
+    cp[-1] = '/';
+    
+    bigmisses += 1;
+    ln = Lst_Last (path);
+    if (ln == NILLNODE) {
+	return ((char *) NULL);
+    } else {
+	p = (Path *) Lst_Datum (ln);
+    }
+    
+    if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
+	return (strdup (name));
+    } else {
+	return ((char *) NULL);
+    }
+#else /* !notdef */
+    if (DEBUG(DIR)) {
+	printf("Looking for \"%s\"...", name);
+    }
+    
+    bigmisses += 1;
+    entry = Hash_FindEntry(&mtimes, name);
+    if (entry != (Hash_Entry *)NULL) {
+	if (DEBUG(DIR)) {
+	    printf("got it (in mtime cache)\n");
+	}
+	return(strdup(name));
+    } else if (stat (name, &stb) == 0) {
+	entry = Hash_CreateEntry(&mtimes, name, (Boolean *)NULL);
+	if (DEBUG(DIR)) {
+	    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
+		    name);
+	}
+	Hash_SetValue(entry, (long)stb.st_mtime);
+	return (strdup (name));
+    } else {
+	if (DEBUG(DIR)) {
+	    printf("failed. Returning NULL\n");
+	}
+	return ((char *)NULL);
+    }
+#endif /* notdef */
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_MTime  --
+ *	Find the modification time of the file described by gn along the
+ *	search path dirSearchPath.
+ * 
+ * Results:
+ *	The modification time or 0 if it doesn't exist
+ *
+ * Side Effects:
+ *	The modification time is placed in the node's mtime slot.
+ *	If the node didn't have a path entry before, and Dir_FindFile
+ *	found one for it, the full name is placed in the path slot.
+ *-----------------------------------------------------------------------
+ */
+int
+Dir_MTime (gn)
+    GNode         *gn;	      /* the file whose modification time is
+			       * desired */
+{
+    char          *fullName;  /* the full pathname of name */
+    struct stat	  stb;	      /* buffer for finding the mod time */
+    Hash_Entry	  *entry;
+    
+    if (gn->type & OP_ARCHV) {
+	return Arch_MTime (gn);
+    } else if (gn->path == (char *)NULL) {
+	fullName = Dir_FindFile (gn->name, dirSearchPath);
+    } else {
+	fullName = gn->path;
+    }
+    
+    if (fullName == (char *)NULL) {
+	fullName = strdup(gn->name);
+    }
+
+    entry = Hash_FindEntry(&mtimes, fullName);
+    if (entry != (Hash_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",
+		    Targ_FmtTime((time_t)(long)Hash_GetValue(entry)), fullName);
+	}
+	stb.st_mtime = (time_t)(long)Hash_GetValue(entry);
+	Hash_DeleteEntry(&mtimes, entry);
+    } else if (stat (fullName, &stb) < 0) {
+	if (gn->type & OP_MEMBER) {
+	    if (fullName != gn->path)
+		free(fullName);
+	    return Arch_MemMTime (gn);
+	} else {
+	    stb.st_mtime = 0;
+	}
+    }
+    if (fullName && gn->path == (char *)NULL) {
+	gn->path = fullName;
+    }
+    
+    gn->mtime = stb.st_mtime;
+    return (gn->mtime);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_AddDir --
+ *	Add the given name to the end of the given path. The order of
+ *	the arguments is backwards so ParseDoDependency can do a
+ *	Lst_ForEach of its list of paths...
+ *
+ * Results:
+ *	none
+ *
+ * Side Effects:
+ *	A structure is added to the list and the directory is 
+ *	read and hashed.
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_AddDir (path, name)
+    Lst           path;	      /* the path to which the directory should be
+			       * added */
+    char          *name;      /* the name of the directory to add */
+{
+    LstNode       ln;	      /* node in case Path structure is found */
+    register Path *p;	      /* pointer to new Path structure */
+    DIR     	  *d;	      /* for reading directory */
+    register struct dirent *dp; /* entry in directory */
+    
+    ln = Lst_Find (openDirectories, (ClientData)name, DirFindName);
+    if (ln != NILLNODE) {
+	p = (Path *)Lst_Datum (ln);
+	if (Lst_Member(path, (ClientData)p) == NILLNODE) {
+	    p->refCount += 1;
+	    (void)Lst_AtEnd (path, (ClientData)p);
+	}
+    } else {
+	if (DEBUG(DIR)) {
+	    printf("Caching %s...", name);
+	    fflush(stdout);
+	}
+	
+	if ((d = opendir (name)) != (DIR *) NULL) {
+	    p = (Path *) emalloc (sizeof (Path));
+	    p->name = strdup (name);
+	    p->hits = 0;
+	    p->refCount = 1;
+	    Hash_InitTable (&p->files, -1);
+	    
+	    /*
+	     * Skip the first two entries -- these will *always* be . and ..
+	     */
+	    (void)readdir(d);
+	    (void)readdir(d);
+	    
+	    while ((dp = readdir (d)) != (struct dirent *) NULL) {
+#ifdef sun
+		/*
+		 * The sun directory library doesn't check for a 0 inode
+		 * (0-inode slots just take up space), so we have to do
+		 * it ourselves.
+		 */
+		if (dp->d_fileno == 0) {
+		    continue;
+		}
+#endif /* sun */
+		(void)Hash_CreateEntry(&p->files, dp->d_name, (Boolean *)NULL);
+	    }
+	    (void) closedir (d);
+	    (void)Lst_AtEnd (openDirectories, (ClientData)p);
+	    (void)Lst_AtEnd (path, (ClientData)p);
+	}
+	if (DEBUG(DIR)) {
+	    printf("done\n");
+	}
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_CopyDir --
+ *	Callback function for duplicating a search path via Lst_Duplicate.
+ *	Ups the reference count for the directory.
+ *
+ * Results:
+ *	Returns the Path it was given.
+ *
+ * Side Effects:
+ *	The refCount of the path is incremented.
+ *
+ *-----------------------------------------------------------------------
+ */
+ClientData
+Dir_CopyDir(p)
+    ClientData p;
+{
+    ((Path *) p)->refCount += 1;
+
+    return ((ClientData)p);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_MakeFlags --
+ *	Make a string by taking all the directories in the given search
+ *	path and preceding them by the given flag. Used by the suffix
+ *	module to create variables for compilers based on suffix search
+ *	paths.
+ *
+ * Results:
+ *	The string mentioned above. Note that there is no space between
+ *	the given flag and each directory. The empty string is returned if
+ *	Things don't go well.
+ *
+ * Side Effects:
+ *	None
+ *-----------------------------------------------------------------------
+ */
+char *
+Dir_MakeFlags (flag, path)
+    char	  *flag;  /* flag which should precede each directory */
+    Lst	    	  path;	  /* list of directories */
+{
+    char	  *str;	  /* the string which will be returned */
+    char	  *tstr;  /* the current directory preceded by 'flag' */
+    LstNode	  ln;	  /* the node of the current directory */
+    Path	  *p;	  /* the structure describing the current directory */
+    
+    str = strdup ("");
+    
+    if (Lst_Open (path) == SUCCESS) {
+	while ((ln = Lst_Next (path)) != NILLNODE) {
+	    p = (Path *) Lst_Datum (ln);
+	    tstr = str_concat (flag, p->name, 0);
+	    str = str_concat (str, tstr, STR_ADDSPACE | STR_DOFREE);
+	}
+	Lst_Close (path);
+    }
+    
+    return (str);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_Destroy --
+ *	Nuke a directory descriptor, if possible. Callback procedure
+ *	for the suffixes module when destroying a search path.
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	If no other path references this directory (refCount == 0),
+ *	the Path and all its data are freed.
+ *
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_Destroy (pp)
+    ClientData 	  pp;	    /* The directory descriptor to nuke */
+{
+    Path    	  *p = (Path *) pp;
+    p->refCount -= 1;
+
+    if (p->refCount == 0) {
+	LstNode	ln;
+
+	ln = Lst_Member (openDirectories, (ClientData)p);
+	(void) Lst_Remove (openDirectories, ln);
+
+	Hash_DeleteTable (&p->files);
+	free((Address)p->name);
+	free((Address)p);
+    }
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_ClearPath --
+ *	Clear out all elements of the given search path. This is different
+ *	from destroying the list, notice.
+ *
+ * Results:
+ *	None.
+ *
+ * Side Effects:
+ *	The path is set to the empty list.
+ *
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_ClearPath(path)
+    Lst	    path; 	/* Path to clear */
+{
+    Path    *p;
+    while (!Lst_IsEmpty(path)) {
+	p = (Path *)Lst_DeQueue(path);
+	Dir_Destroy((ClientData) p);
+    }
+}
+	    
+
+/*-
+ *-----------------------------------------------------------------------
+ * Dir_Concat --
+ *	Concatenate two paths, adding the second to the end of the first.
+ *	Makes sure to avoid duplicates.
+ *
+ * Results:
+ *	None
+ *
+ * Side Effects:
+ *	Reference counts for added dirs are upped.
+ *
+ *-----------------------------------------------------------------------
+ */
+void
+Dir_Concat(path1, path2)
+    Lst	    path1;  	/* Dest */
+    Lst	    path2;  	/* Source */
+{
+    LstNode ln;
+    Path    *p;
+
+    for (ln = Lst_First(path2); ln != NILLNODE; ln = Lst_Succ(ln)) {
+	p = (Path *)Lst_Datum(ln);
+	if (Lst_Member(path1, (ClientData)p) == NILLNODE) {
+	    p->refCount += 1;
+	    (void)Lst_AtEnd(path1, (ClientData)p);
+	}
+    }
+}
+
+/********** DEBUG INFO **********/
+void
+Dir_PrintDirectories()
+{
+    LstNode	ln;
+    Path	*p;
+    
+    printf ("#*** Directory Cache:\n");
+    printf ("# Stats: %d hits %d misses %d near misses %d losers (%d%%)\n",
+	      hits, misses, nearmisses, bigmisses,
+	      (hits+bigmisses+nearmisses ?
+	       hits * 100 / (hits + bigmisses + nearmisses) : 0));
+    printf ("# %-20s referenced\thits\n", "directory");
+    if (Lst_Open (openDirectories) == SUCCESS) {
+	while ((ln = Lst_Next (openDirectories)) != NILLNODE) {
+	    p = (Path *) Lst_Datum (ln);
+	    printf ("# %-20s %10d\t%4d\n", p->name, p->refCount, p->hits);
+	}
+	Lst_Close (openDirectories);
+    }
+}
+
+static int DirPrintDir (p, dummy)
+    ClientData	p;
+    ClientData	dummy;
+{ 
+    printf ("%s ", ((Path *) p)->name);
+    return (dummy ? 0 : 0);
+}
+
+void
+Dir_PrintPath (path)
+    Lst	path;
+{
+    Lst_ForEach (path, DirPrintDir, (ClientData)0);
+}