Merge euidaccess etc. from coreutils.

[gnulib.git] / m4 / readdir.m4

diff --git a/m4/readdir.m4 b/m4/readdir.m4
index 0bfc459..2c4bbab 100644 (file)
--- a/m4/readdir.m4
+++ b/m4/readdir.m4
@@ -1,16 +1,29 @@
-#serial 1
+#serial 5
 
-dnl FIXME: describe
+dnl SunOS's readdir is broken in such a way that rm.c has to add extra code
+dnl to test whether a NULL return value really means there are no more files
+dnl in the directory.
+dnl
+dnl Detect the problem by creating a directory containing 300 files (254 not
+dnl counting . and .. is the minimum) and see if a loop doing `readdir; unlink'
+dnl removes all of them.
+dnl
+dnl Define HAVE_WORKING_READDIR if readdir does *not* have this problem.
 
-AC_DEFUN(jm_FUNC_READDIR,
+dnl Written by Jim Meyering.
+
+AC_DEFUN([jm_FUNC_READDIR],
 [dnl
 AC_REQUIRE([AC_HEADER_DIRENT])
-AC_CHECK_HEADERS(string.h)
+AC_CHECK_HEADERS_ONCE(string.h)
 AC_CACHE_CHECK([for working readdir], jm_cv_func_working_readdir,
-  [AC_TRY_RUN(
-  changequote(<<, >>)dnl
-  <<
-#   include <stdio.h>
+  [dnl
+  # Arrange for deletion of the temporary directory this test creates, in
+  # case the test itself fails to delete everything -- as happens on Sunos.
+  ac_clean_files="$ac_clean_files conf-dir"
+
+  AC_TRY_RUN(
+[#   include <stdio.h>
 #   include <sys/types.h>
 #   if HAVE_STRING_H
 #    include <string.h>
@@ -37,15 +50,18 @@ AC_CACHE_CHECK([for working readdir], jm_cv_func_working_readdir,
      (Basename[0] == '.' && (Basename[1] == '\0' \
                             || (Basename[1] == '.' && Basename[2] == '\0')))
 
+/* Don't try to use replacement mkdir; it wouldn't resolve at link time.  */
+#   undef mkdir
+
     static void
     create_300_file_dir (const char *dir)
     {
       int i;
 
       if (mkdir (dir, 0700))
-       exit (1);
+       abort ();
       if (chdir (dir))
-       exit (1);
+       abort ();
 
       for (i = 0; i < 300; i++)
        {
@@ -55,13 +71,13 @@ AC_CACHE_CHECK([for working readdir], jm_cv_func_working_readdir,
          sprintf (file_name, "%03d", i);
          out = fopen (file_name, "w");
          if (!out)
-           exit (1);
+           abort ();
          if (fclose (out) == EOF)
-           exit (1);
+           abort ();
        }
 
       if (chdir (".."))
-       exit (1);
+       abort ();
     }
 
     static void
@@ -70,11 +86,11 @@ AC_CACHE_CHECK([for working readdir], jm_cv_func_working_readdir,
       DIR *dirp;
 
       if (chdir (dir))
-       exit (1);
+       abort ();
 
       dirp = opendir (".");
       if (dirp == NULL)
-       exit (1);
+       abort ();
 
       while (1)
        {
@@ -86,12 +102,12 @@ AC_CACHE_CHECK([for working readdir], jm_cv_func_working_readdir,
            continue;
 
          if (unlink (dp->d_name))
-           exit (1);
+           abort ();
        }
       closedir (dirp);
 
       if (chdir (".."))
-       exit (1);
+       abort ();
 
       if (rmdir (dir))
        exit (1);
@@ -104,22 +120,13 @@ AC_CACHE_CHECK([for working readdir], jm_cv_func_working_readdir,
       create_300_file_dir (dir);
       remove_dir (dir);
       exit (0);
-    }
-  >>,
-  changequote([, ])dnl
+    }],
   jm_cv_func_working_readdir=yes,
   jm_cv_func_working_readdir=no,
   jm_cv_func_working_readdir=no)])
 
-  if test x = y; then
-    dnl This code is deliberately never run via ./configure.
-    dnl FIXME: this is a gross hack to make autoheader put an entry
-    dnl for this HAVE_-prefixed symbol in config.h.in.
-    AC_CHECK_FUNCS(WORKING_READDIR)
-  fi
-
   if test $jm_cv_func_working_readdir = yes; then
-    ac_kludge=HAVE_WORKING_READDIR
-    AC_DEFINE_UNQUOTED($ac_kludge)
+    AC_DEFINE(HAVE_WORKING_READDIR, 1,
+      [Define if readdir is found to work properly in some unusual cases. ])
   fi
 ])