diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index df8be3bf805af53e1e33fb0cc1d0c85e44457878..e4175ea3e641c7b99863891b36918a796fd4faa9 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -2372,35 +2372,6 @@ AC_DEFUN([GLIBCXX_CHECK_MATH11_PROTO], [
AC_LANG_RESTORE
])
-dnl
-dnl Check whether macros, etc are present for <system_error>
-dnl
-AC_DEFUN([GLIBCXX_CHECK_SYSTEM_ERROR], [
-
-m4_pushdef([n_syserr], [1])dnl
-m4_foreach([syserr], [EOWNERDEAD, ENOTRECOVERABLE, ENOLINK, EPROTO, ENODATA,
- ENOSR, ENOSTR, ETIME, EBADMSG, ECANCELED,
- EOVERFLOW, ENOTSUP, EIDRM, ETXTBSY,
- ECHILD, ENOSPC, EPERM,
- ETIMEDOUT, EWOULDBLOCK],
-[m4_pushdef([SYSERR], m4_toupper(syserr))dnl
-AC_MSG_CHECKING([for syserr])
-AC_CACHE_VAL([glibcxx_cv_system_error[]n_syserr], [
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <errno.h>]],
- [int i = syserr;])],
- [glibcxx_cv_system_error[]n_syserr=yes],
- [glibcxx_cv_system_error[]n_syserr=no])
-])
-AC_MSG_RESULT([$glibcxx_cv_system_error[]n_syserr])
-if test x"$glibcxx_cv_system_error[]n_syserr" = x"yes"; then
- AC_DEFINE([HAVE_]SYSERR, 1, [Define if ]syserr[ exists.])
-fi
-m4_define([n_syserr], m4_incr(n_syserr))dnl
-m4_popdef([SYSERR])dnl
-])
-m4_popdef([n_syserr])dnl
-])
-
dnl
dnl Check for what type of C headers to use.
dnl
diff --git a/libstdc++-v3/config/os/generic/error_constants.h b/libstdc++-v3/config/os/generic/error_constants.h
index b5b0ea6b9ad3b22c81e9df3b6e2d2fd23ab6cf82..0d34f7179b6407acdd36e458870e193bda5676e6 100644
--- a/libstdc++-v3/config/os/generic/error_constants.h
+++ b/libstdc++-v3/config/os/generic/error_constants.h
@@ -48,7 +48,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
bad_address = EFAULT,
bad_file_descriptor = EBADF,
-#ifdef _GLIBCXX_HAVE_EBADMSG
+#ifdef EBADMSG
bad_message = EBADMSG,
#endif
@@ -68,7 +68,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
function_not_supported = ENOSYS,
host_unreachable = EHOSTUNREACH,
-#ifdef _GLIBCXX_HAVE_EIDRM
+#ifdef EIDRM
identifier_removed = EIDRM,
#endif
@@ -86,13 +86,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
no_buffer_space = ENOBUFS,
no_child_process = ECHILD,
-#ifdef _GLIBCXX_HAVE_ENOLINK
+#ifdef ENOLINK
no_link = ENOLINK,
#endif
no_lock_available = ENOLCK,
-#ifdef _GLIBCXX_HAVE_ENODATA
+#ifdef ENODATA
no_message_available = ENODATA,
#endif
@@ -100,7 +100,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
no_protocol_option = ENOPROTOOPT,
no_space_on_device = ENOSPC,
-#ifdef _GLIBCXX_HAVE_ENOSR
+#ifdef ENOSR
no_stream_resources = ENOSR,
#endif
@@ -111,18 +111,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
not_a_directory = ENOTDIR,
not_a_socket = ENOTSOCK,
-#ifdef _GLIBCXX_HAVE_ENOSTR
+#ifdef ENOSTR
not_a_stream = ENOSTR,
#endif
not_connected = ENOTCONN,
not_enough_memory = ENOMEM,
-#ifdef _GLIBCXX_HAVE_ENOTSUP
+#ifdef ENOTSUP
not_supported = ENOTSUP,
#endif
-#ifdef _GLIBCXX_HAVE_ECANCELED
+#ifdef ECANCELED
operation_canceled = ECANCELED,
#endif
@@ -131,13 +131,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operation_not_supported = EOPNOTSUPP,
operation_would_block = EWOULDBLOCK,
-#ifdef _GLIBCXX_HAVE_EOWNERDEAD
+#ifdef EOWNERDEAD
owner_dead = EOWNERDEAD,
#endif
permission_denied = EACCES,
-#ifdef _GLIBCXX_HAVE_EPROTO
+#ifdef EPROTO
protocol_error = EPROTO,
#endif
@@ -147,15 +147,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
resource_unavailable_try_again = EAGAIN,
result_out_of_range = ERANGE,
-#ifdef _GLIBCXX_HAVE_ENOTRECOVERABLE
+#ifdef ENOTRECOVERABLE
state_not_recoverable = ENOTRECOVERABLE,
#endif
-#ifdef _GLIBCXX_HAVE_ETIME
+#ifdef ETIME
stream_timeout = ETIME,
#endif
-#ifdef _GLIBCXX_HAVE_ETXTBSY
+#ifdef ETXTBSY
text_file_busy = ETXTBSY,
#endif
@@ -165,7 +165,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
too_many_links = EMLINK,
too_many_symbolic_link_levels = ELOOP,
-#ifdef _GLIBCXX_HAVE_EOVERFLOW
+#ifdef EOVERFLOW
value_too_large = EOVERFLOW,
#endif
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 771814110a130941ad4b532670706a3ebf1799e8..9138ba2258880da7a1c697a92b25a106297839d2 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -183,7 +183,6 @@ GLIBCXX_ENABLE_VTABLE_VERIFY([no])
# Checks for operating systems support that doesn't require linking.
GLIBCXX_CHECK_STDIO_PROTO
GLIBCXX_CHECK_MATH11_PROTO
-GLIBCXX_CHECK_SYSTEM_ERROR
GLIBCXX_CHECK_UCHAR_H
# For the streamoff typedef.
diff --git a/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/93151.cc b/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/93151.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2d8efc76deb37d2c6b8ce97afbf349b67be3a332
--- /dev/null
+++ b/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/93151.cc
@@ -0,0 +1,23 @@
+// { dg-do compile { target c++11 } }
+
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// PR libstdc++/93151
+#undef _XOPEN_SOURCE
+#define _XOPEN_SOURCE 600
+#include <system_error>
diff --git a/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc b/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
index 0f006ae47d93b39dcfc17ec9badf5315609c2a79..72c4b53124d8de840d9196b1616417c448ffcb7c 100644
--- a/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
+++ b/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
@@ -34,7 +34,7 @@ void test01()
TEST_ERRC(bad_address);
TEST_ERRC(bad_file_descriptor);
-#ifdef _GLIBCXX_HAVE_EBADMSG
+#ifdef EBADMSG
TEST_ERRC(bad_message);
#endif
@@ -54,7 +54,7 @@ void test01()
TEST_ERRC(function_not_supported);
TEST_ERRC(host_unreachable);
-#ifdef _GLIBCXX_HAVE_EIDRM
+#ifdef EIDRM
TEST_ERRC(identifier_removed);
#endif
@@ -72,23 +72,23 @@ void test01()
TEST_ERRC(no_buffer_space);
TEST_ERRC(no_child_process);
-#ifdef _GLIBCXX_HAVE_ENOLINK
+#ifdef ENOLINK
TEST_ERRC(no_link);
#endif
TEST_ERRC(no_lock_available);
-#ifdef _GLIBCXX_HAVE_ENODATA
+#ifdef ENODATA
TEST_ERRC(no_message_available);
#endif
-#ifdef _GLIBCXX_HAVE_ENOMSG
+#ifdef ENOMSG
TEST_ERRC(no_message);
#endif
TEST_ERRC(no_protocol_option);
TEST_ERRC(no_space_on_device);
-#ifdef _GLIBCXX_HAVE_ENOSR
+#ifdef ENOSR
TEST_ERRC(no_stream_resources);
#endif
@@ -99,15 +99,15 @@ void test01()
TEST_ERRC(not_a_directory);
TEST_ERRC(not_a_socket);
-#ifdef _GLIBCXX_HAVE_ENOSTR
+#ifdef ENOSTR
TEST_ERRC(not_a_stream);
#endif
- TEST_ERRC(not_connected);
+ TEST_ERRC(not_connected);
TEST_ERRC(not_enough_memory);
TEST_ERRC(not_supported);
-#ifdef _GLIBCXX_HAVE_ECANCELED
+#ifdef ECANCELED
TEST_ERRC(operation_canceled);
#endif
@@ -116,31 +116,31 @@ void test01()
TEST_ERRC(operation_not_supported);
TEST_ERRC(operation_would_block);
-#ifdef _GLIBCXX_HAVE_EOWNERDEAD
+#ifdef EOWNERDEAD
TEST_ERRC(owner_dead);
#endif
TEST_ERRC(permission_denied);
-#ifdef _GLIBCXX_HAVE_EPROTO
+#ifdef EPROTO
TEST_ERRC(protocol_error);
#endif
TEST_ERRC(protocol_not_supported);
TEST_ERRC(read_only_file_system);
TEST_ERRC(resource_deadlock_would_occur);
- TEST_ERRC(resource_unavailable_try_again);
+ TEST_ERRC(resource_unavailable_try_again);
TEST_ERRC(result_out_of_range);
-#ifdef _GLIBCXX_HAVE_ENOTRECOVERABLE
+#ifdef ENOTRECOVERABLE
TEST_ERRC(state_not_recoverable);
#endif
-#ifdef _GLIBCXX_HAVE_ETIME
+#ifdef ETIME
TEST_ERRC(stream_timeout);
#endif
-#ifdef _GLIBCXX_HAVE_ETXTBSY
+#ifdef ETXTBSY
TEST_ERRC(text_file_busy);
#endif
@@ -150,7 +150,7 @@ void test01()
TEST_ERRC(too_many_links);
TEST_ERRC(too_many_symbolic_link_levels);
-#ifdef _GLIBCXX_HAVE_EOVERFLOW
+#ifdef EOVERFLOW
TEST_ERRC(value_too_large);
#endif