From 6b12d8b5c30a84aa5767b1b18ecf5ba5e99a1654 Mon Sep 17 00:00:00 2001
From: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Fri, 2 Oct 2020 13:25:43 +0800
Subject: [PATCH] [libcxx] Port to NuttX(https://nuttx.apache.org/) RTOS

Since NuttX conform to POSIX standard, the code need to add is very simple

Co-authored-by: YAMAMOTO Takashi <yamamoto@midokura.com>

Differential Revision: https://reviews.llvm.org/D88718
---
 include/__config                |  3 ++-
 include/__locale                |  2 ++
 include/support/nuttx/xlocale.h | 18 ++++++++++++++++++
 src/include/config_elast.h      |  4 ++++
 src/locale.cpp                  |  2 +-
 5 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 include/support/nuttx/xlocale.h

diff --git a/include/__config libcxx/include/__config
index eeef9c53a9f..9ace3b46028 100644
--- a/include/__config
+++ libcxx/include/__config
@@ -1117,6 +1117,7 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  if defined(__FreeBSD__) || \
       defined(__wasi__) || \
       defined(__NetBSD__) || \
+      defined(__NuttX__) || \
       defined(__linux__) || \
       defined(__GNU__) || \
       defined(__APPLE__) || \
@@ -1219,7 +1220,7 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  endif
 #endif
 
-#if defined(__BIONIC__) || defined(__CloudABI__) ||                            \
+#if defined(__BIONIC__) || defined(__CloudABI__) || defined(__NuttX__) ||      \
     defined(__Fuchsia__) || defined(__wasi__) || defined(_LIBCPP_HAS_MUSL_LIBC)
 #define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
 #endif
diff --git a/include/__locale libcxx/include/__locale
index 125adcf68c8..ebededf066b 100644
--- a/include/__locale
+++ libcxx/include/__locale
@@ -22,6 +22,8 @@
 #if defined(_LIBCPP_MSVCRT_LIKE)
 # include <cstring>
 # include <support/win32/locale_win32.h>
+#elif defined(__NuttX__)
+# include <support/nuttx/xlocale.h>
 #elif defined(_AIX)
 # include <support/ibm/xlocale.h>
 #elif defined(__ANDROID__)
diff --git a/include/support/nuttx/xlocale.h libcxx/include/support/nuttx/xlocale.h
new file mode 100644
index 00000000000..b70d6200504
--- /dev/null
+++ libcxx/include/support/nuttx/xlocale.h
@@ -0,0 +1,18 @@
+// -*- C++ -*-
+//===-------------------- support/nuttx/xlocale.h -------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_SUPPORT_NUTTX_XLOCALE_H
+#define _LIBCPP_SUPPORT_NUTTX_XLOCALE_H
+
+#if defined(__NuttX__)
+#include <support/xlocale/__posix_l_fallback.h>
+#include <support/xlocale/__strtonum_fallback.h>
+#endif // __NuttX__
+
+#endif
diff --git a/src/include/config_elast.h libcxx/src/include/config_elast.h
index 501cbc4ffeb..3113f9fb5cd 100644
--- a/src/include/config_elast.h
+++ libcxx/src/include/config_elast.h
@@ -17,10 +17,14 @@
 #include <errno.h>
 #endif
 
+// Note: _LIBCPP_ELAST needs to be defined only on platforms
+// where strerror/strerror_r can't handle out-of-range errno values.
 #if defined(ELAST)
 #define _LIBCPP_ELAST ELAST
 #elif defined(_NEWLIB_VERSION)
 #define _LIBCPP_ELAST __ELASTERROR
+#elif defined(__NuttX__)
+// No _LIBCPP_ELAST needed on NuttX
 #elif defined(__Fuchsia__)
 // No _LIBCPP_ELAST needed on Fuchsia
 #elif defined(__wasi__)
diff --git a/src/locale.cpp libcxx/src/locale.cpp
index 5fdc14992f8..ed93727b544 100644
--- a/src/locale.cpp
+++ libcxx/src/locale.cpp
@@ -30,7 +30,7 @@
 #include "__sso_allocator"
 #if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
 #include "support/win32/locale_win32.h"
-#elif !defined(__BIONIC__)
+#elif !defined(__BIONIC__) && !defined(__NuttX__)
 #include <langinfo.h>
 #endif
 #include <stdlib.h>
-- 
2.17.1