From 93070671eae44f24ba822383e17571a39257c637 Mon Sep 17 00:00:00 2001
From: Alexandre Oliva <oliva@adacore.com>
Date: Thu, 23 Jun 2022 23:20:53 -0300
Subject: libstdc++: check for openat

rtems6.0 has fdopendir, and fcntl.h defines AT_FDCWD and declares
openat, but there's no openat in libc.  Adjust dir-common.h to not
assume ::openat just because of AT_FDCWD.


for  libstdc++-v3/ChangeLog

	* acinclude.m4 (GLIBCXX_CHECK_FILESYSTEM_DEPS): Check for
	openat.
	* configure, config.h.in: Rebuilt.
	* src/filesystem/dir-common.h (openat): Use ::openat if
	_GLIBCXX_HAVE_OPENAT.
	* src/filesystem/dir.cc (dir_and_pathname): Use dirfd if
	_GLIBCXX_HAVE_OPENAT.
---
 libstdc++-v3/configure | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

(limited to 'libstdc++-v3/configure')

diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 9b94fd71e42..eac60392121 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -77177,6 +77177,61 @@ $as_echo "$glibcxx_cv_dirfd" >&6; }
 
 $as_echo "#define HAVE_DIRFD 1" >>confdefs.h
 
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for openat" >&5
+$as_echo_n "checking for openat... " >&6; }
+if ${glibcxx_cv_openat+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+      if test x$gcc_no_link = xyes; then
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <fcntl.h>
+int
+main ()
+{
+int fd = ::openat(AT_FDCWD, "", 0);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  glibcxx_cv_openat=yes
+else
+  glibcxx_cv_openat=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+  if test x$gcc_no_link = xyes; then
+  as_fn_error $? "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <fcntl.h>
+int
+main ()
+{
+int fd = ::openat(AT_FDCWD, "", 0);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+  glibcxx_cv_openat=yes
+else
+  glibcxx_cv_openat=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_openat" >&5
+$as_echo "$glibcxx_cv_openat" >&6; }
+  if test $glibcxx_cv_openat = yes; then
+
+$as_echo "#define HAVE_OPENAT 1" >>confdefs.h
+
   fi
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for unlinkat" >&5
 $as_echo_n "checking for unlinkat... " >&6; }
-- 
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