1 files changed, 95 insertions, 0 deletions
diff --git a/m4/open.m4 b/m4/open.m4
new file mode 100644
index 00000000000..68253e15ffd
--- /dev/null
+++ b/m4/open.m4
@@ -0,0 +1,95 @@
+# open.m4 serial 15
+dnl Copyright (C) 2007-2017 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.
+
+AC_DEFUN([gl_FUNC_OPEN],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([gl_PREPROC_O_CLOEXEC])
+  case "$host_os" in
+    mingw* | pw*)
+      REPLACE_OPEN=1
+      ;;
+    *)
+      dnl open("foo/") should not create a file when the file name has a
+      dnl trailing slash.  FreeBSD only has the problem on symlinks.
+      AC_CHECK_FUNCS_ONCE([lstat])
+      if test "$gl_cv_macro_O_CLOEXEC" != yes; then
+        REPLACE_OPEN=1
+      fi
+      AC_CACHE_CHECK([whether open recognizes a trailing slash],
+        [gl_cv_func_open_slash],
+        [# Assume that if we have lstat, we can also check symlinks.
+          if test $ac_cv_func_lstat = yes; then
+            touch conftest.tmp
+            ln -s conftest.tmp conftest.lnk
+          fi
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <fcntl.h>
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+int main ()
+{
+  int result = 0;
+#if HAVE_LSTAT
+  if (open ("conftest.lnk/", O_RDONLY) != -1)
+    result |= 1;
+#endif
+  if (open ("conftest.sl/", O_CREAT, 0600) >= 0)
+    result |= 2;
+  return result;
+}]])],
+            [gl_cv_func_open_slash=yes],
+            [gl_cv_func_open_slash=no],
+            [
+changequote(,)dnl
+             case "$host_os" in
+               freebsd* | aix* | hpux* | solaris2.[0-9] | solaris2.[0-9].*)
+                 gl_cv_func_open_slash="guessing no" ;;
+               *)
+                 gl_cv_func_open_slash="guessing yes" ;;
+             esac
+changequote([,])dnl
+            ])
+          rm -f conftest.sl conftest.tmp conftest.lnk
+        ])
+      case "$gl_cv_func_open_slash" in
+        *no)
+          AC_DEFINE([OPEN_TRAILING_SLASH_BUG], [1],
+            [Define to 1 if open() fails to recognize a trailing slash.])
+          REPLACE_OPEN=1
+          ;;
+      esac
+      ;;
+  esac
+  dnl Replace open() for supporting the gnulib-defined fchdir() function,
+  dnl to keep fchdir's bookkeeping up-to-date.
+  m4_ifdef([gl_FUNC_FCHDIR], [
+    if test $REPLACE_OPEN = 0; then
+      gl_TEST_FCHDIR
+      if test $HAVE_FCHDIR = 0; then
+        REPLACE_OPEN=1
+      fi
+    fi
+  ])
+  dnl Replace open() for supporting the gnulib-defined O_NONBLOCK flag.
+  m4_ifdef([gl_NONBLOCKING_IO], [
+    if test $REPLACE_OPEN = 0; then
+      gl_NONBLOCKING_IO
+      if test $gl_cv_have_open_O_NONBLOCK != yes; then
+        REPLACE_OPEN=1
+      fi
+    fi
+  ])
+])
+
+# Prerequisites of lib/open.c.
+AC_DEFUN([gl_PREREQ_OPEN],
+[
+  AC_REQUIRE([gl_PROMOTED_TYPE_MODE_T])
+  :
+])