Module Name: src
Committed By: rillig
Date: Thu Sep 21 20:30:59 UTC 2023
Modified Files:
src/usr.bin/make: dir.c
Log Message:
make: remove obsolete comments, clean up comments and identifiers
No binary change, except for the line numbers in assertions.
To generate a diff of this commit:
cvs rdiff -u -r1.282 -r1.283 src/usr.bin/make/dir.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/make/dir.c
diff -u src/usr.bin/make/dir.c:1.282 src/usr.bin/make/dir.c:1.283
--- src/usr.bin/make/dir.c:1.282 Fri Jun 23 04:56:54 2023
+++ src/usr.bin/make/dir.c Thu Sep 21 20:30:59 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: dir.c,v 1.282 2023/06/23 04:56:54 rillig Exp $ */
+/* $NetBSD: dir.c,v 1.283 2023/09/21 20:30:59 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -83,7 +83,7 @@
*
* Dir_End Clean up the module.
*
- * Dir_SetPATH Set ${.PATH} to reflect state of dirSearchPath.
+ * Dir_SetPATH Set ${.PATH} to reflect the state of dirSearchPath.
*
* Dir_HasWildcards
* Returns true if the name given it needs to
@@ -94,13 +94,12 @@
* from the search path.
*
* Dir_FindFile Searches for a file on a given search path.
- * If it exists, the entire path is returned.
- * Otherwise NULL is returned.
+ * If it exists, returns the entire path, otherwise NULL.
*
* Dir_FindHereOrAbove
- * Search for a path in the current directory and
- * then all the directories above it in turn until
- * the path is found or we reach the root ("/").
+ * Search for a path in the current directory and then
+ * all the directories above it in turn, until the path
+ * is found or the root directory ("/") is reached.
*
* Dir_UpdateMTime
* Update the modification time and path of a node with
@@ -114,11 +113,6 @@
* preceded by the command flag and all of them
* separated by a space.
*
- * Dir_Destroy Destroy an element of a search path. Frees up all
- * things that can be freed for the element as long
- * as the element is no longer referenced by any other
- * search path.
- *
* SearchPath_Clear
* Resets a search path to the empty list.
*
@@ -138,7 +132,7 @@
#include "job.h"
/* "@(#)dir.c 8.2 (Berkeley) 1/2/94" */
-MAKE_RCSID("$NetBSD: dir.c,v 1.282 2023/06/23 04:56:54 rillig Exp $");
+MAKE_RCSID("$NetBSD: dir.c,v 1.283 2023/09/21 20:30:59 rillig Exp $");
/*
* A search path is a list of CachedDir structures. A CachedDir has in it the
@@ -152,26 +146,21 @@ MAKE_RCSID("$NetBSD: dir.c,v 1.282 2023/
* All previously-read directories are kept in openDirs, which 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 caching 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:
+ * This cache is used by the multi-level transformation code in suff.c, which
+ * tends to search for far more files than in regular explicit targets. After
+ * a directory has been cached, any later changes to that directory are not
+ * reflected in the cache. To keep the cache up to date, there are several
+ * ideas:
*
* 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
+ * this is very inefficient due to the number of checks performed 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 (as of 1993 or earlier) 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.
+ * 2) use readdir() to search the directories, keeping them open between
+ * checks. Around 1993 or earlier, this didn't slow down the process too
+ * much, but it consumed one file descriptor per open directory, which
+ * was critical on the then-current operating systems, as many limited
+ * the number of open file descriptors to 20 or 32.
*
* 3) record the mtime of the directory in the CachedDir structure and
* verify the directory hasn't changed since the contents were cached.
@@ -184,9 +173,9 @@ MAKE_RCSID("$NetBSD: dir.c,v 1.282 2023/
* number of reloadings and if the number goes over a (small) limit,
* resort to using stat in its place.
*
- * An additional thing to consider is that pmake is used primarily to create
- * C programs and until recently (as of 1993 or earlier) pcc-based compilers
- * refused to allow you to specify where the resulting object file should be
+ * An additional thing to consider is that make is used primarily to create
+ * C programs and until recently (as of 1993 or earlier), pcc-based compilers
+ * didn't have an option to specify where the resulting object file should be
* placed. This forced all objects to be created in the current directory.
* This isn't meant as a full excuse, just an explanation of some of the
* reasons for the caching used here.
@@ -212,7 +201,7 @@ MAKE_RCSID("$NetBSD: dir.c,v 1.282 2023/
/* A cache for the filenames in a directory. */
struct CachedDir {
/*
- * Name of directory, either absolute or relative to the current
+ * Name of the directory, either absolute or relative to the current
* directory. The name is not normalized in any way, that is, "."
* and "./." are different.
*
@@ -273,8 +262,7 @@ static CachedDir *dotLast = NULL;
*
* 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...
+ * there won't be two rules to update a single file, so this should be ok.
*/
static HashTable mtimes;
@@ -338,7 +326,7 @@ CachedDir_Unref(CachedDir *dir)
free(dir);
}
-/* Update the value of the CachedDir variable, updating the reference counts. */
+/* Update the value of 'var', updating the reference counts. */
static void
CachedDir_Assign(CachedDir **var, CachedDir *dir)
{
@@ -487,7 +475,7 @@ Dir_InitCur(const char *newCurdir)
return;
/*
- * Our build directory is not the same as our source directory.
+ * The build directory is not the same as the source directory.
* Keep this one around too.
*/
dir = SearchPath_Add(NULL, newCurdir);
@@ -498,7 +486,7 @@ Dir_InitCur(const char *newCurdir)
}
/*
- * (Re)initialize "dot" (current/object directory) path hash.
+ * (Re)initialize "dot" (the current/object directory).
* Some directories may be cached.
*/
void
@@ -599,8 +587,6 @@ Dir_SetSYSPATH(void)
* XXX: This code is not 100% correct ([^]] fails etc.). I really don't think
* that make(1) should be expanding patterns, because then you have to set a
* mechanism for escaping the expansion!
- *
- * Return true if the word should be expanded, false otherwise.
*/
bool
Dir_HasWildcards(const char *name)
@@ -637,20 +623,14 @@ Dir_HasWildcards(const char *name)
}
/*
- * See if any files match the pattern and add their names to the 'expansions'
- * list if they do.
+ * See if any files as seen from 'dir' match 'pattern', and add their names
+ * to 'expansions' if they do.
*
- * This is incomplete -- wildcards are only expanded in the final path
- * component, but not in directories like src/lib*c/file*.c, but it
- * will do for now (now being 1993 until at least 2020). To expand these,
+ * Wildcards are only expanded in the final path component, but not in
+ * directories like src/lib*c/file*.c. To expand these wildcards,
* delegate the work to the shell, using the '!=' variable assignment
* operator, the ':sh' variable modifier or the ':!...!' variable modifier,
* such as in ${:!echo src/lib*c/file*.c!}.
- *
- * Input:
- * pattern Pattern to look for
- * dir Directory to search
- * expansion Place to store the results
*/
static void
DirMatchFiles(const char *pattern, CachedDir *dir, StringList *expansions)
@@ -824,7 +804,7 @@ DirExpandCurly(const char *word, const c
}
-/* Expand the pattern in each of the directories from the path. */
+/* Expand 'pattern' in each of the directories from 'path'. */
static void
DirExpandPath(const char *pattern, SearchPath *path, StringList *expansions)
{
@@ -861,11 +841,6 @@ SearchPath_ExpandMiddle(SearchPath *path
prefix = bmake_strsedup(pattern, wildcardComponent + 1);
/*
- * XXX: Check the "the directory is added to the path" part.
- * It is probably surprising that the directory before a
- * wildcard gets added to the path.
- */
- /*
* XXX: Only the first match of the prefix in the path is
* taken, any others are ignored. The expectation may be
* that the pattern is expanded in the whole path.
@@ -880,7 +855,7 @@ SearchPath_ExpandMiddle(SearchPath *path
* path contains ../Etc/Object and we're looking for Etc, it won't
* be found. Ah well. Probably not important.
*
- * XXX: Check whether the above comment is still true.
+ * TODO: Check whether the above comment is still true.
*/
if (dirpath == NULL)
return;
@@ -921,12 +896,8 @@ SearchPath_Expand(SearchPath *path, cons
goto done;
}
- /* At this point, the pattern does not contain '{'. */
-
slash = strchr(pattern, '/');
if (slash == NULL) {
- /* The pattern has no directory component. */
-
/* First the files in dot. */
DirMatchFiles(pattern, dot, expansions);
/* Then the files in every other directory on the path. */
@@ -972,13 +943,13 @@ done:
}
/*
- * Find if the file with the given name exists in the given path.
+ * Find if 'base' exists in 'dir'.
* Return the freshly allocated path to the file, or NULL.
*/
static char *
DirLookup(CachedDir *dir, const char *base)
{
- char *file; /* the current filename to check */
+ char *file;
DEBUG1(DIR, " %s ...\n", dir->name);
@@ -994,7 +965,7 @@ DirLookup(CachedDir *dir, const char *ba
/*
- * Find if the file with the given name exists in the given directory.
+ * Find if 'name' exists in 'dir'.
* Return the freshly allocated path to the file, or NULL.
*/
static char *
@@ -1016,12 +987,12 @@ DirLookupSubdir(CachedDir *dir, const ch
}
/*
- * Find if the file with the given name exists in the given path.
- * Return the freshly allocated path to the file, the empty string, or NULL.
- * Returning the empty string means that the search should be terminated.
+ * Find if 'name' (which has basename 'base') exists in 'dir'.
+ * Return the freshly allocated path to the file, an empty string, or NULL.
+ * Returning an empty string means that the search should be terminated.
*/
static char *
-DirLookupAbs(CachedDir *dir, const char *name, const char *cp)
+DirLookupAbs(CachedDir *dir, const char *name, const char *base)
{
const char *dnp; /* pointer into dir->name */
const char *np; /* pointer into name */
@@ -1037,10 +1008,10 @@ DirLookupAbs(CachedDir *dir, const char
for (dnp = dir->name, np = name;
*dnp != '\0' && *dnp == *np; dnp++, np++)
continue;
- if (*dnp != '\0' || np != cp - 1)
+ if (*dnp != '\0' || np != base - 1)
return NULL;
- if (!HashSet_Contains(&dir->files, cp)) {
+ if (!HashSet_Contains(&dir->files, base)) {
DEBUG0(DIR, " must be here but isn't -- returning\n");
return bmake_strdup(""); /* to terminate the search */
}
@@ -1090,11 +1061,11 @@ FindFileRelative(SearchPath *path, bool
if (dot != NULL) {
checkedDot = true;
if ((file = DirLookupSubdir(dot, name)) != NULL)
- goto found;
+ goto done;
}
if (cur != NULL &&
(file = DirLookupSubdir(cur, name)) != NULL)
- goto found;
+ goto done;
}
for (ln = path->dirs.first; ln != NULL; ln = ln->next) {
@@ -1107,18 +1078,18 @@ FindFileRelative(SearchPath *path, bool
checkedDot = true;
}
if ((file = DirLookupSubdir(dir, name)) != NULL)
- goto found;
+ goto done;
}
if (seenDotLast) {
if (dot != NULL && !checkedDot) {
checkedDot = true;
if ((file = DirLookupSubdir(dot, name)) != NULL)
- goto found;
+ goto done;
}
if (cur != NULL &&
(file = DirLookupSubdir(cur, name)) != NULL)
- goto found;
+ goto done;
}
if (checkedDot) {
@@ -1128,12 +1099,12 @@ FindFileRelative(SearchPath *path, bool
*/
DEBUG0(DIR, " Checked . already, returning NULL\n");
file = NULL;
- goto found;
+ goto done;
}
return false;
-found:
+done:
*out_file = file;
return true;
}
@@ -1145,16 +1116,6 @@ FindFileAbsolute(SearchPath *path, bool
char *file;
SearchPathNode *ln;
- /*
- * For absolute names, compare directory path prefix against
- * the the directory path of each member on the search path
- * for an exact match. If we have an exact match on any member
- * of the search path, use the cached contents of that member
- * to lookup the final file component. If that lookup fails we
- * can safely assume that the file does not exist at all.
- * This is signified by DirLookupAbs() returning an empty
- * string.
- */
DEBUG0(DIR, " Trying exact path matches...\n");
if (!seenDotLast && cur != NULL &&
@@ -1187,13 +1148,6 @@ found:
/*
* Find the file with the given name along the given search path.
*
- * If the file is found in a directory that 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.
- *
* Input:
* name the file to find
* path the directories to search, or NULL
@@ -1206,7 +1160,7 @@ Dir_FindFile(const char *name, SearchPat
{
char *file; /* the current filename to check */
bool seenDotLast = false; /* true if we should search dot last */
- struct cached_stat cst; /* Buffer for stat, if necessary */
+ struct cached_stat cst;
const char *trailing_dot = ".";
const char *base = str_basename(name);
@@ -1236,18 +1190,16 @@ Dir_FindFile(const char *name, SearchPat
SearchPathNode *ln;
/*
- * We look through all the directories on the path seeking one
+ * Look through all the directories on the path seeking one
* which contains the final component of the given name. If
- * such a file 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.
+ * such a file is found, return its pathname.
+ * If there is no such file, go on to phase two.
*
- * No matter what, we always look for the file in the current
- * directory before anywhere else (unless we found the magic
- * DOTLAST path, in which case we search it last) and we *do
- * not* add the ./ to it if it exists.
+ * No matter what, always look for the file in the current
+ * directory before anywhere else (unless the path contains
+ * the magic '.DOTLAST', in which case search it last).
* This is so there are no conflicts between what the user
- * specifies (fish.c) and what pmake finds (./fish.c).
+ * specifies (fish.c) and what make finds (./fish.c).
*/
if (!seenDotLast && (file = DirFindDot(name, base)) != NULL)
return file;
@@ -1264,30 +1216,14 @@ Dir_FindFile(const char *name, SearchPat
return file;
}
- /*
- * We didn't find the file on any directory in the search path.
- * 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).
- * [ This no longer applies: If we find such a file, 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 (base == name) {
DEBUG0(DIR, " failed.\n");
misses++;
return NULL;
}
- if (*base == '\0') {
- /* we were given a trailing "/" */
- base = trailing_dot;
- }
+ if (*base == '\0')
+ base = trailing_dot; /* we were given a trailing "/" */
if (name[0] != '/') {
if (FindFileRelative(path, seenDotLast, name, &file))
@@ -1298,16 +1234,7 @@ Dir_FindFile(const char *name, SearchPat
}
/*
- * 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
+ * We cannot add the directory onto the search path because
* of this amusing case:
* $(INSTALLDIR)/$(FILE): $(FILE)
*
@@ -1315,75 +1242,40 @@ Dir_FindFile(const char *name, SearchPat
* When searching for $(FILE), we will find it in $(INSTALLDIR)
* b/c we added it here. This is not good...
*/
-#if 0
- {
- CachedDir *dir;
- char *prefix;
-
- if (base == trailing_dot) {
- base = strrchr(name, '/');
- base++;
- }
- prefix = bmake_strsedup(name, base - 1);
- (void)SearchPath_Add(path, prefix);
- free(prefix);
-
- bigmisses++;
- if (path->last == NULL)
- return NULL;
-
- dir = path->last->datum;
- if (HashSet_Contains(&dir->files, base))
- return bmake_strdup(name);
- return NULL;
- }
-#else
+
DEBUG1(DIR, " Looking for \"%s\" ...\n", name);
bigmisses++;
- if (cached_stat(name, &cst) == 0) {
+ if (cached_stat(name, &cst) == 0)
return bmake_strdup(name);
- }
DEBUG0(DIR, " failed. Returning NULL\n");
return NULL;
-#endif
}
/*
- * Search for a path starting at a given directory and then working our way
- * up towards the root.
- *
- * Input:
- * here starting directory
- * search_path the relative path we are looking for
- *
- * Results:
- * The found path, or NULL.
+ * Search for 'needle' starting at the directory 'here' and then working our
+ * way up towards the root directory. Return the allocated path, or NULL.
*/
char *
-Dir_FindHereOrAbove(const char *here, const char *search_path)
+Dir_FindHereOrAbove(const char *here, const char *needle)
{
struct cached_stat cst;
char *dirbase, *dirbase_end;
char *try, *try_end;
- /* copy out our starting point */
dirbase = bmake_strdup(here);
dirbase_end = dirbase + strlen(dirbase);
- /* loop until we determine a result */
for (;;) {
-
- /* try and stat(2) it ... */
- try = str_concat3(dirbase, "/", search_path);
+ try = str_concat3(dirbase, "/", needle);
if (cached_stat(try, &cst) != -1) {
- /*
- * success! if we found a file, chop off
- * the filename so we return a directory.
- */
if ((cst.cst_mode & S_IFMT) != S_IFDIR) {
+ /*
+ * Chop off the filename, to return a
+ * directory.
+ */
try_end = try + strlen(try);
while (try_end > try && *try_end != '/')
try_end--;
@@ -1396,16 +1288,10 @@ Dir_FindHereOrAbove(const char *here, co
}
free(try);
- /*
- * nope, we didn't find it. if we used up dirbase we've
- * reached the root and failed.
- */
if (dirbase_end == dirbase)
break; /* failed! */
- /*
- * truncate dirbase from the end to move up a dir
- */
+ /* Truncate dirbase from the end to move up a dir. */
while (dirbase_end > dirbase && *dirbase_end != '/')
dirbase_end--;
*dirbase_end = '\0'; /* chop! */
@@ -1476,10 +1362,10 @@ ResolveFullName(GNode *gn)
}
/*
- * Search gn along dirSearchPath and store its modification time in gn->mtime.
- * If no file is found, store 0 instead.
+ * Search 'gn' along 'dirSearchPath' and store its modification time in
+ * 'gn->mtime'. If no file is found, store 0 instead.
*
- * The found file is stored in gn->path, unless the node already had a path.
+ * The found file is stored in 'gn->path', unless the node already had a path.
*/
void
Dir_UpdateMTime(GNode *gn, bool forceRefresh)
@@ -1562,14 +1448,14 @@ CacheNewDir(const char *name, SearchPath
}
/*
- * Read the list of filenames in the directory and store the result
- * in openDirs.
+ * Read the list of filenames in the directory 'name' and store the result
+ * in 'openDirs'.
*
- * If a path is given, append the directory to that path.
+ * If a search path is given, append the directory to that path.
*
* Input:
* path The path to which the directory should be
- * added, or NULL to only add the directory to openDirs
+ * added, or NULL to only add the directory to openDirs.
* name The name of the directory to add.
* The name is not normalized in any way.
* Output:
@@ -1628,16 +1514,8 @@ Dir_CopyDirSearchPath(void)
/*
* 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.
- *
- * Input:
- * flag flag which should precede each directory
- * path list of directories
- *
- * 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.
+ * variables for compilers based on suffix search paths. Note that there is no
+ * space between the given flag and each directory.
*/
char *
SearchPath_ToFlags(SearchPath *path, const char *flag)
@@ -1709,7 +1587,6 @@ percentage(int num, int den)
return den != 0 ? num * 100 / den : 0;
}
-/********** DEBUG INFO **********/
void
Dir_PrintDirectories(void)
{
