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src/usr.bin/make/dir.c

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/* $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;
}
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