1 files changed, 64 insertions, 33 deletions

diff --git a/gl/m4/fcntl-o.m4 b/gl/m4/fcntl-o.m4
index 43aa1325..8020c481 100644
--- a/gl/m4/fcntl-o.m4
+++ b/gl/m4/fcntl-o.m4
@@ -1,15 +1,17 @@
 # fcntl-o.m4
-# serial 8
-dnl Copyright (C) 2006, 2009-2024 Free Software Foundation, Inc.
+# serial 12
+dnl Copyright (C) 2006, 2009-2025 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
+dnl This file is offered as-is, without any warranty.
 
 dnl Written by Paul Eggert.
 
 AC_PREREQ([2.60])
 
-# Test whether the flags O_NOATIME and O_NOFOLLOW actually work.
+# Test whether the flags O_DIRECTORY, O_NOATIME and O_NOFOLLOW actually work.
+# Define HAVE_WORKING_O_DIRECTORY to 1 if O_DIRECTORY works, or to 0 otherwise.
 # Define HAVE_WORKING_O_NOATIME to 1 if O_NOATIME works, or to 0 otherwise.
 # Define HAVE_WORKING_O_NOFOLLOW to 1 if O_NOFOLLOW works, or to 0 otherwise.
 AC_DEFUN([gl_FCNTL_O_FLAGS],
@@ -30,16 +32,23 @@ AC_DEFUN([gl_FCNTL_O_FLAGS],
            #else /* on Windows with MSVC */
            # include <io.h>
            # include <stdlib.h>
-           # defined sleep(n) _sleep ((n) * 1000)
+           # define sleep(n) _sleep ((n) * 1000)
            #endif
+           #include <errno.h>
            #include <fcntl.h>
            ]GL_MDA_DEFINES[
+           #ifndef O_DIRECTORY
+            #define O_DIRECTORY 0
+           #endif
            #ifndef O_NOATIME
             #define O_NOATIME 0
            #endif
            #ifndef O_NOFOLLOW
             #define O_NOFOLLOW 0
            #endif
+           #ifndef O_SEARCH
+            #define O_SEARCH O_RDONLY
+           #endif
            static int const constants[] =
             {
               O_CREAT, O_EXCL, O_NOCTTY, O_TRUNC, O_APPEND,
@@ -52,31 +61,38 @@ AC_DEFUN([gl_FCNTL_O_FLAGS],
             {
               static char const sym[] = "conftest.sym";
               if (symlink ("/dev/null", sym) != 0)
-                result |= 2;
+                result |= 1;
               else
                 {
                   int fd = open (sym, O_WRONLY | O_NOFOLLOW | O_CREAT, 0);
                   if (fd >= 0)
                     {
                       close (fd);
-                      result |= 4;
+                      result |= 3;
                     }
                 }
               if (unlink (sym) != 0 || symlink (".", sym) != 0)
-                result |= 2;
+                result |= 1;
               else
                 {
                   int fd = open (sym, O_RDONLY | O_NOFOLLOW);
                   if (fd >= 0)
                     {
                       close (fd);
-                      result |= 4;
+                      result |= 3;
                     }
                 }
               unlink (sym);
             }
             #endif
             {
+              int fd = open ("confdefs.h", O_SEARCH | O_DIRECTORY);
+              if (!(fd < 0 && errno == ENOTDIR))
+                result |= 4;
+              if (0 <= fd)
+                close (fd);
+            }
+            {
               static char const file[] = "confdefs.h";
               int fd = open (file, O_RDONLY | O_NOATIME);
               if (fd < 0)
@@ -111,31 +127,46 @@ AC_DEFUN([gl_FCNTL_O_FLAGS],
             }
             return result;]])],
        [gl_cv_header_working_fcntl_h=yes],
-       [case $? in #(
-        4) gl_cv_header_working_fcntl_h='no (bad O_NOFOLLOW)';; #(
-        64) gl_cv_header_working_fcntl_h='no (bad O_NOATIME)';; #(
-        68) gl_cv_header_working_fcntl_h='no (bad O_NOATIME, O_NOFOLLOW)';; #(
-         *) gl_cv_header_working_fcntl_h='no';;
-        esac],
-       [case "$host_os" in
-                             # Guess 'no' on native Windows.
-          mingw* | windows*) gl_cv_header_working_fcntl_h='no' ;;
-          *)                 gl_cv_header_working_fcntl_h=cross-compiling ;;
-        esac
-       ])
-    ])
+       [AS_CASE([$?],
+          dnl We cannot catch exit code 1 or 2 here, because
+          dnl - exit code 1 can occur through a compilation error on mingw (e.g.
+          dnl   when O_NOCTTY, O_NONBLOCK, O_SYNC are not defined) or when
+          dnl   result = 1, whereas
+          dnl - exit code 2 can occur through a compilation error on MSVC (e.g.
+          dnl   again when O_NOCTTY, O_NONBLOCK, O_SYNC are not defined) or when
+          dnl   result = 2.
+          [ 3], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW)"],
+          [ 4], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY)"],
+          [ 7], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW, O_DIRECTORY)"],
+          [64], [gl_cv_header_working_fcntl_h="no (bad O_NOATIME)"],
+          [67], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW, O_NOATIME)"],
+          [68], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY, O_NOATIME)"],
+          [71], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW, O_DIRECTORY, O_NOATIME)"],
+          [gl_cv_header_working_fcntl_h="no"])],
+       [AS_CASE([$host_os,$gl_cross_guess_normal],
+          # The O_DIRECTORY test is known to fail on Mac OS X 10.4.11 (2007)
+          # (see <https://bugs.gnu.org/78509#95>)
+          # and to succeed on Mac OS X 10.5.8 [darwin9.8.0] (2009).
+          # Guess it fails on Mac OS X 10.4.x and earlier.
+          [darwin[[0-8]].*yes],
+             [gl_cv_header_working_fcntl_h="guessing no (bad O_DIRECTORY)"],
+          # Known to be "no" on native MS-Windows.
+          [mingw* | windows*],
+             [gl_cv_header_working_fcntl_h=no],
+          [gl_cv_header_working_fcntl_h=$gl_cross_guess_normal])])])
+
+  AS_CASE([$gl_cv_header_working_fcntl_h],
+    [*O_DIRECTORY* | *no], [gl_val=0], [gl_val=1])
+  AC_DEFINE_UNQUOTED([HAVE_WORKING_O_DIRECTORY], [$gl_val],
+    [Define to 1 if O_DIRECTORY works, 0 otherwise.])
 
-  case $gl_cv_header_working_fcntl_h in #(
-  *O_NOATIME* | no | cross-compiling) ac_val=0;; #(
-  *) ac_val=1;;
-  esac
-  AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOATIME], [$ac_val],
-    [Define to 1 if O_NOATIME works.])
+  AS_CASE([$gl_cv_header_working_fcntl_h],
+    [*O_NOATIME* | *no], [gl_val=0], [gl_val=1])
+  AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOATIME], [$gl_val],
+    [Define to 1 if O_NOATIME works, 0 otherwise.])
 
-  case $gl_cv_header_working_fcntl_h in #(
-  *O_NOFOLLOW* | no | cross-compiling) ac_val=0;; #(
-  *) ac_val=1;;
-  esac
-  AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOFOLLOW], [$ac_val],
-    [Define to 1 if O_NOFOLLOW works.])
+  AS_CASE([$gl_cv_header_working_fcntl_h],
+    [*O_NOFOLLOW* | *no], [gl_val=0], [gl_val=1])
+  AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOFOLLOW], [$gl_val],
+    [Define to 1 if O_NOFOLLOW works, 0 otherwise.])
 ])