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[src/trunk]: src/usr.bin/make make(1): remove redundant struct make_stat
details: https://anonhg.NetBSD.org/src/rev/cfd8ebd020f2
branches: trunk
changeset: 946047:cfd8ebd020f2
user: rillig <rillig%NetBSD.org@localhost>
date: Sat Nov 14 19:24:24 2020 +0000
description:
make(1): remove redundant struct make_stat
In the cache for stat(2) and lstat(2), only one of the two timestamps
was ever used. To prevent a result from stat(2) leaking into the cache
for lstat(2), there have been two completely separate caches all the
time. Using different fields in the struct was therefore unnecessary.
By removing the redundant field, the internal struct in the cache is the
same as the external struct. This makes one of them redundant, thus
struct make_stat has been renamed to cached_stat, which better describes
its purpose, and the internal struct cache_st has been removed.
Just as before, the cache prevents any direct access to its internal
data. When passing it to the caller, it is copied.
Just as before, the field names of struct cached_stat cannot correspond
to those from struct stat, since the latter are often defined as macros.
Therefore they are prefixed with cst instead of st.
The redundancy had been added on 2020-06-05.
diffstat:
usr.bin/make/dir.c | 88 +++++++++++++++++++---------------------------------
usr.bin/make/dir.h | 12 +++---
usr.bin/make/meta.c | 20 ++++++------
3 files changed, 49 insertions(+), 71 deletions(-)
diffs (truncated from 323 to 300 lines):
diff -r 500e86218db0 -r cfd8ebd020f2 usr.bin/make/dir.c
--- a/usr.bin/make/dir.c Sat Nov 14 18:47:21 2020 +0000
+++ b/usr.bin/make/dir.c Sat Nov 14 19:24:24 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: dir.c,v 1.207 2020/11/14 11:51:58 rillig Exp $ */
+/* $NetBSD: dir.c,v 1.208 2020/11/14 19:24:24 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -134,7 +134,7 @@
#include "job.h"
/* "@(#)dir.c 8.2 (Berkeley) 1/2/94" */
-MAKE_RCSID("$NetBSD: dir.c,v 1.207 2020/11/14 11:51:58 rillig Exp $");
+MAKE_RCSID("$NetBSD: dir.c,v 1.208 2020/11/14 19:24:24 rillig Exp $");
#define DIR_DEBUG0(text) DEBUG0(DIR, text)
#define DIR_DEBUG1(fmt, arg1) DEBUG1(DIR, fmt, arg1)
@@ -300,31 +300,22 @@
static HashTable lmtimes; /* same as mtimes but for lstat */
-/*
- * We use stat(2) a lot, cache the results.
- * mtime and mode are all we care about.
- */
-struct cache_st {
- time_t lmtime; /* lstat; XXX: is probably redundant */
- time_t mtime; /* stat */
- mode_t mode;
-};
-
typedef enum CachedStatsFlags {
CST_NONE = 0,
CST_LSTAT = 1 << 0, /* call lstat(2) instead of stat(2) */
CST_UPDATE = 1 << 1 /* ignore existing cached entry */
} CachedStatsFlags;
-/* Returns 0 and the result of stat(2) or lstat(2) in *mst, or -1 on error. */
+/* Returns 0 and the result of stat(2) or lstat(2) in *out_cst,
+ * or -1 on error. */
static int
-cached_stats(const char *pathname, struct make_stat *mst,
+cached_stats(const char *pathname, struct cached_stat *out_cst,
CachedStatsFlags flags)
{
HashTable *tbl = flags & CST_LSTAT ? &lmtimes : &mtimes;
HashEntry *entry;
struct stat sys_st;
- struct cache_st *cst;
+ struct cached_stat *cst;
int rc;
if (pathname == NULL || pathname[0] == '\0')
@@ -335,31 +326,19 @@
if (entry != NULL && !(flags & CST_UPDATE)) {
cst = HashEntry_Get(entry);
- mst->mst_mode = cst->mode;
- mst->mst_mtime = (flags & CST_LSTAT) ? cst->lmtime : cst->mtime;
- /* XXX: Checking for mst_mtime != 0 is probably redundant since
- * nonexistent files are not cached. */
- if (mst->mst_mtime != 0) {
- DIR_DEBUG2("Using cached time %s for %s\n",
- Targ_FmtTime(mst->mst_mtime), pathname);
- return 0;
- }
- /* Continue with the normal lookup to see whether the file has been
- * created in the meantime. */
+ *out_cst = *cst;
+ DIR_DEBUG2("Using cached time %s for %s\n",
+ Targ_FmtTime(cst->cst_mtime), pathname);
+ return 0;
}
- rc = (flags & CST_LSTAT)
- ? lstat(pathname, &sys_st)
- : stat(pathname, &sys_st);
+ rc = (flags & CST_LSTAT ? lstat : stat)(pathname, &sys_st);
if (rc == -1)
- return -1;
+ return -1; /* don't cache negative lookups */
if (sys_st.st_mtime == 0)
sys_st.st_mtime = 1; /* avoid confusion with missing file */
- mst->mst_mode = sys_st.st_mode;
- mst->mst_mtime = sys_st.st_mtime;
-
if (entry != NULL)
cst = entry->value;
else {
@@ -368,12 +347,11 @@
memset(cst, 0, sizeof *cst);
HashEntry_Set(entry, cst);
}
- if (flags & CST_LSTAT) {
- cst->lmtime = sys_st.st_mtime;
- } else {
- cst->mtime = sys_st.st_mtime;
- }
- cst->mode = sys_st.st_mode;
+
+ cst->cst_mtime = sys_st.st_mtime;
+ cst->cst_mode = sys_st.st_mode;
+
+ *out_cst = *cst;
DIR_DEBUG2(" Caching %s for %s\n",
Targ_FmtTime(sys_st.st_mtime), pathname);
@@ -381,15 +359,15 @@
}
int
-cached_stat(const char *pathname, struct make_stat *st)
+cached_stat(const char *pathname, struct cached_stat *cst)
{
- return cached_stats(pathname, st, CST_NONE);
+ return cached_stats(pathname, cst, CST_NONE);
}
int
-cached_lstat(const char *pathname, struct make_stat *st)
+cached_lstat(const char *pathname, struct cached_stat *cst)
{
- return cached_stats(pathname, st, CST_LSTAT);
+ return cached_stats(pathname, cst, CST_LSTAT);
}
/* Initialize the directories module. */
@@ -896,13 +874,13 @@
static char *
DirLookupSubdir(CachedDir *dir, const char *name)
{
- struct make_stat mst;
+ struct cached_stat cst;
char *file = dir == dot ? bmake_strdup(name)
: str_concat3(dir->name, "/", name);
DIR_DEBUG1("checking %s ...\n", file);
- if (cached_stat(file, &mst) == 0) {
+ if (cached_stat(file, &cst) == 0) {
nearmisses++;
return file;
}
@@ -991,7 +969,7 @@
const char *base; /* Terminal name of file */
Boolean hasLastDot = FALSE; /* true if we should search dot last */
Boolean hasSlash; /* true if 'name' contains a / */
- struct make_stat mst; /* Buffer for stat, if necessary */
+ struct cached_stat cst; /* Buffer for stat, if necessary */
const char *trailing_dot = ".";
/*
@@ -1219,7 +1197,7 @@
DIR_DEBUG1(" Looking for \"%s\" ...\n", name);
bigmisses++;
- if (cached_stat(name, &mst) == 0) {
+ if (cached_stat(name, &cst) == 0) {
return bmake_strdup(name);
}
@@ -1242,7 +1220,7 @@
char *
Dir_FindHereOrAbove(const char *here, const char *search_path)
{
- struct make_stat mst;
+ struct cached_stat cst;
char *dirbase, *dirbase_end;
char *try, *try_end;
@@ -1255,12 +1233,12 @@
/* try and stat(2) it ... */
try = str_concat3(dirbase, "/", search_path);
- if (cached_stat(try, &mst) != -1) {
+ if (cached_stat(try, &cst) != -1) {
/*
* success! if we found a file, chop off
* the filename so we return a directory.
*/
- if ((mst.mst_mode & S_IFMT) != S_IFDIR) {
+ if ((cst.cst_mode & S_IFMT) != S_IFDIR) {
try_end = try + strlen(try);
while (try_end > try && *try_end != '/')
try_end--;
@@ -1299,8 +1277,8 @@
void
Dir_UpdateMTime(GNode *gn, Boolean recheck)
{
- char *fullName; /* the full pathname of name */
- struct make_stat mst; /* buffer for finding the mod time */
+ char *fullName;
+ struct cached_stat cst;
CachedStatsFlags flags;
if (gn->type & OP_ARCHV) {
@@ -1357,7 +1335,7 @@
fullName = bmake_strdup(gn->name);
flags = recheck ? CST_UPDATE : CST_NONE;
- if (cached_stats(fullName, &mst, flags) < 0) {
+ if (cached_stats(fullName, &cst, flags) < 0) {
if (gn->type & OP_MEMBER) {
if (fullName != gn->path)
free(fullName);
@@ -1365,13 +1343,13 @@
return;
}
- mst.mst_mtime = 0;
+ cst.cst_mtime = 0;
}
if (fullName != NULL && gn->path == NULL)
gn->path = fullName;
- gn->mtime = mst.mst_mtime;
+ gn->mtime = cst.cst_mtime;
}
/* Read the list of filenames in the directory and store the result
diff -r 500e86218db0 -r cfd8ebd020f2 usr.bin/make/dir.h
--- a/usr.bin/make/dir.h Sat Nov 14 18:47:21 2020 +0000
+++ b/usr.bin/make/dir.h Sat Nov 14 19:24:24 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: dir.h,v 1.33 2020/11/08 09:34:55 rillig Exp $ */
+/* $NetBSD: dir.h,v 1.34 2020/11/14 19:24:24 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -112,12 +112,12 @@
SearchPath *Dir_CopyDirSearchPath(void);
/* Stripped-down variant of struct stat. */
-struct make_stat {
- time_t mst_mtime;
- mode_t mst_mode;
+struct cached_stat {
+ time_t cst_mtime;
+ mode_t cst_mode;
};
-int cached_lstat(const char *, struct make_stat *);
-int cached_stat(const char *, struct make_stat *);
+int cached_lstat(const char *, struct cached_stat *);
+int cached_stat(const char *, struct cached_stat *);
#endif /* MAKE_DIR_H */
diff -r 500e86218db0 -r cfd8ebd020f2 usr.bin/make/meta.c
--- a/usr.bin/make/meta.c Sat Nov 14 18:47:21 2020 +0000
+++ b/usr.bin/make/meta.c Sat Nov 14 19:24:24 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: meta.c,v 1.142 2020/11/14 17:39:59 rillig Exp $ */
+/* $NetBSD: meta.c,v 1.143 2020/11/14 19:24:24 rillig Exp $ */
/*
* Implement 'meta' mode.
@@ -410,7 +410,7 @@
meta_needed(GNode *gn, const char *dname, const char *tname,
char *objdir, int verbose)
{
- struct make_stat mst;
+ struct cached_stat cst;
if (verbose)
verbose = DEBUG(META);
@@ -441,7 +441,7 @@
}
/* The object directory may not exist. Check it.. */
- if (cached_stat(dname, &mst) != 0) {
+ if (cached_stat(dname, &cst) != 0) {
if (verbose)
debug_printf("Skipping meta for %s: no .OBJDIR\n", gn->name);
return FALSE;
@@ -1125,7 +1125,7 @@
int pid;
int x;
StringListNode *cmdNode;
- struct make_stat mst;
+ struct cached_stat cst;
if (buf == NULL) {
bufsz = 8 * BUFSIZ;
@@ -1382,8 +1382,8 @@
if ((strstr("tmp", p)))
break;
- if ((link_src != NULL && cached_lstat(p, &mst) < 0) ||
- (link_src == NULL && cached_stat(p, &mst) < 0)) {
+ if ((link_src != NULL && cached_lstat(p, &cst) < 0) ||
+ (link_src == NULL && cached_stat(p, &cst) < 0)) {
if (!meta_ignore(gn, p))
append_if_new(missingFiles, p);
}
@@ -1443,7 +1443,7 @@
DEBUG3(META, "%s: %d: looking for: %s\n",
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