statat: now obsolete

* lib/openat.h (statat, lstatat): Now deprecated.
All uses removed, and replaced with fstatat.
* modules/statat: Mark as obsolete, because it’s confusing:
it’s not clear whether it should use AT_NO_AUTOMOUNT,
which is implied by stat and by lstat, but not by fstatat.
* tests/test-statat.c: Disable deprecated-declarations warnings.

11 files changed, 36 insertions, 13 deletions

diff --git a/ChangeLog b/ChangeLog
index 58873a1762..294f6286f3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2022-03-09  Paul Eggert  <eggert@cs.ucla.edu>
 
+	statat: now obsolete
+	* lib/openat.h (statat, lstatat): Now deprecated.
+	All uses removed, and replaced with fstatat.
+	* modules/statat: Mark as obsolete, because it’s confusing:
+	it’s not clear whether it should use AT_NO_AUTOMOUNT,
+	which is implied by stat and by lstat, but not by fstatat.
+	* tests/test-statat.c: Disable deprecated-declarations warnings.
+
 	fts: be consistent about AT_NO_AUTOMOUNT
 	* lib/fts.c (fts_stat): Use fstatat with AT_NO_AUTOMOUNT
 	consistently, instead of sometimes using stat (which implies
diff --git a/NEWS b/NEWS
index c13a115ada..8f90d8e958 100644
--- a/NEWS
+++ b/NEWS
@@ -66,6 +66,9 @@ User visible incompatible changes
 
 Date        Modules         Changes
 
+2022-03-09  statat          This module is deprecated.  Use fstatat instead,
+                            to specify whether you want AT_NO_AUTOMOUNT.
+
 2022-01-05  stack           This module now uses idx_t instead of size_t
                             for indexes and counts.
 
diff --git a/lib/fchownat.c b/lib/fchownat.c
index c0d97db98b..ff368d356d 100644
--- a/lib/fchownat.c
+++ b/lib/fchownat.c
@@ -103,7 +103,7 @@ rpl_fchownat (int fd, char const *file, uid_t owner, gid_t group, int flag)
     struct stat st;
     if (len && file[len - 1] == '/')
       {
-        if (statat (fd, file, &st))
+        if (fstatat (fd, file, &st, 0))
           return -1;
         if (flag == AT_SYMLINK_NOFOLLOW)
           return fchownat (fd, file, owner, group, 0);
diff --git a/lib/openat.h b/lib/openat.h
index 5c8ff90b80..56919ef8dc 100644
--- a/lib/openat.h
+++ b/lib/openat.h
@@ -98,12 +98,14 @@ lchmodat (int fd, char const *file, mode_t mode)
 #  define STATAT_INLINE _GL_INLINE
 # endif
 
+_GL_ATTRIBUTE_DEPRECATED
 STATAT_INLINE int
 statat (int fd, char const *name, struct stat *st)
 {
   return fstatat (fd, name, st, 0);
 }
 
+_GL_ATTRIBUTE_DEPRECATED
 STATAT_INLINE int
 lstatat (int fd, char const *name, struct stat *st)
 {
diff --git a/lib/renameatu.c b/lib/renameatu.c
index 0eb33ab6fd..b4e317d6e5 100644
--- a/lib/renameatu.c
+++ b/lib/renameatu.c
@@ -133,12 +133,13 @@ renameatu (int fd1, char const *src, int fd2, char const *dst,
       break;
 
     case RENAME_NOREPLACE:
-      /* This has a race between the call to lstatat and the calls to
-         renameat below.  This lstatat is needed even if RENAME_EXCL
+      /* This has a race between the call to fstatat and the calls to
+         renameat below.  This fstatat is needed even if RENAME_EXCL
          is defined, because RENAME_EXCL is buggy on macOS 11.2:
          renameatx_np (fd, "X", fd, "X", RENAME_EXCL) incorrectly
          succeeds when X exists.  */
-      if (lstatat (fd2, dst, &dst_st) == 0 || errno == EOVERFLOW)
+      if (fstatat (fd2, dst, &dst_st, AT_SYMLINK_NOFOLLOW) == 0
+          || errno == EOVERFLOW)
         return errno_fail (EEXIST);
       if (errno != ENOENT)
         return -1;
@@ -164,14 +165,14 @@ renameatu (int fd1, char const *src, int fd2, char const *dst,
      the source does not exist, or if the destination cannot be turned
      into a directory, give up now.  Otherwise, strip trailing slashes
      before calling rename.  */
-  if (lstatat (fd1, src, &src_st))
+  if (fstatat (fd1, src, &src_st, AT_SYMLINK_NOFOLLOW))
     return -1;
   if (dst_found_nonexistent)
     {
       if (!S_ISDIR (src_st.st_mode))
         return errno_fail (ENOENT);
     }
-  else if (lstatat (fd2, dst, &dst_st))
+  else if (fstatat (fd2, dst, &dst_st, AT_SYMLINK_NOFOLLOW))
     {
       if (errno != ENOENT || !S_ISDIR (src_st.st_mode))
         return -1;
@@ -196,7 +197,7 @@ renameatu (int fd1, char const *src, int fd2, char const *dst,
           goto out;
         }
       strip_trailing_slashes (src_temp);
-      if (lstatat (fd1, src_temp, &src_st))
+      if (fstatat (fd1, src_temp, &src_st, AT_SYMLINK_NOFOLLOW))
         {
           rename_errno = errno;
           goto out;
@@ -213,7 +214,7 @@ renameatu (int fd1, char const *src, int fd2, char const *dst,
           goto out;
         }
       strip_trailing_slashes (dst_temp);
-      if (lstatat (fd2, dst_temp, &dst_st))
+      if (fstatat (fd2, dst_temp, &dst_st, AT_SYMLINK_NOFOLLOW))
         {
           if (errno != ENOENT)
             {
diff --git a/lib/unlinkat.c b/lib/unlinkat.c
index eae60074d4..c9ff3ab2f1 100644
--- a/lib/unlinkat.c
+++ b/lib/unlinkat.c
@@ -58,7 +58,7 @@ rpl_unlinkat (int fd, char const *name, int flag)
          rule of letting unlink("link-to-dir/") attempt to unlink a
          directory.  */
       struct stat st;
-      result = lstatat (fd, name, &st);
+      result = fstatat (fd, name, &st, AT_SYMLINK_NOFOLLOW);
       if (result == 0 || errno == EOVERFLOW)
         {
           /* Trailing NUL will overwrite the trailing slash.  */
@@ -71,7 +71,8 @@ rpl_unlinkat (int fd, char const *name, int flag)
           memcpy (short_name, name, len);
           while (len && ISSLASH (short_name[len - 1]))
             short_name[--len] = '\0';
-          if (len && (lstatat (fd, short_name, &st) || S_ISLNK (st.st_mode)))
+          if (len && (fstatat (fd, short_name, &st, AT_SYMLINK_NOFOLLOW)
+                      || S_ISLNK (st.st_mode)))
             {
               free (short_name);
               errno = EPERM;
diff --git a/modules/fchownat b/modules/fchownat
index ea2f2e678c..49c4b18096 100644
--- a/modules/fchownat
+++ b/modules/fchownat
@@ -19,7 +19,6 @@ lchown          [test $HAVE_FCHOWNAT = 0 || test $REPLACE_FCHOWNAT = 1]
 openat-die      [test $HAVE_FCHOWNAT = 0 || test $REPLACE_FCHOWNAT = 1]
 openat-h        [test $HAVE_FCHOWNAT = 0 || test $REPLACE_FCHOWNAT = 1]
 save-cwd        [test $HAVE_FCHOWNAT = 0 || test $REPLACE_FCHOWNAT = 1]
-statat          [test $REPLACE_FCHOWNAT = 1]
 
 configure.ac:
 gl_FUNC_FCHOWNAT
diff --git a/modules/renameatu b/modules/renameatu
index 5ce8e47587..e0c1ce3176 100644
--- a/modules/renameatu
+++ b/modules/renameatu
@@ -13,7 +13,6 @@ extensions
 fcntl-h
 filenamecat-lgpl [test $HAVE_RENAMEAT = 0 || test $REPLACE_RENAMEAT = 1]
 openat-h         [test $HAVE_RENAMEAT = 0 || test $REPLACE_RENAMEAT = 1]
-statat           [test $REPLACE_RENAMEAT = 1]
 stdbool          [test $REPLACE_RENAMEAT = 1]
 at-internal      [test $HAVE_RENAMEAT = 0]
 filename         [test $HAVE_RENAMEAT = 0]
diff --git a/modules/statat b/modules/statat
index 074d342bd8..bf274e054d 100644
--- a/modules/statat
+++ b/modules/statat
@@ -1,6 +1,13 @@
 Description:
 statat() and lstatat() functions: Return info about a file at a directory.
 
+Status:
+obsolete
+
+Notice:
+This module is obsolete.  Please use fstatat instead, and decide
+whether you want AT_NO_AUTOMOUNT in each fstatat call.
+
 Files:
 lib/statat.c
 
diff --git a/modules/unlinkat b/modules/unlinkat
index 0efc1cc1b2..ed11c1e971 100644
--- a/modules/unlinkat
+++ b/modules/unlinkat
@@ -13,7 +13,6 @@ extensions
 fcntl-h         [test $HAVE_UNLINKAT = 0 || test $REPLACE_UNLINKAT = 1]
 openat-h        [test $HAVE_UNLINKAT = 0 || test $REPLACE_UNLINKAT = 1]
 sys_stat        [test $HAVE_UNLINKAT = 0 || test $REPLACE_UNLINKAT = 1]
-statat          [test $REPLACE_UNLINKAT = 1]
 at-internal     [test $HAVE_UNLINKAT = 0]
 errno           [test $HAVE_UNLINKAT = 0]
 fchdir          [test $HAVE_UNLINKAT = 0]
diff --git a/tests/test-statat.c b/tests/test-statat.c
index a573604e1c..f46c3f58b5 100644
--- a/tests/test-statat.c
+++ b/tests/test-statat.c
@@ -18,6 +18,10 @@
 
 #include "openat.h"
 
+#if 4 < __GNUC__ + (3 <= __GNUC_MINOR__)
+# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif
+
 #include "signature.h"
 SIGNATURE_CHECK (statat, int, (int, char const *, struct stat *));
 SIGNATURE_CHECK (lstatat, int, (int, char const *, struct stat *));