From 680fd80663ac11ca7586b69cd68c373da1557e81 Mon Sep 17 00:00:00 2001
From: Ryan Prichard <rprichard@google.com>
Date: Wed, 20 Sep 2023 14:45:55 -0700
Subject: [PATCH] Use std::filesystem when libc++ is new enough

_LIBCPP_VERSION in external/libcxx is 8000. When _LIBCPP_VERSION is
newer, assume it's the new libc++ toolchain prebuilt, which has a
finalized std::filesystem, and use std::filesystem instead. To make
Soong happy, keep the android.hardware.automotive@libc++fs library for
now but stub out the C++ source files and make the
android::hardware::automotive::filesystem namespace an alias for
std::filesystem.

Bug: 152067309
Bug: 175635923
Test: treehugger
Test: m android.hardware.automotive.can@1.0-service
Test: m android.hardware.automotive@libc++fs
Change-Id: I7aede74cda0122434d972a075d7c7a9933845450
---
 .../default/libc++fs/include/automotive/filesystem | 14 ++++++++++++++
 .../libc++fs/src/filesystem/directory_iterator.cpp |  8 ++++++++
 .../default/libc++fs/src/filesystem/operations.cpp |  7 +++++++
 3 files changed, 29 insertions(+)

diff --git a/automotive/can/1.0/default/libc++fs/include/automotive/filesystem b/automotive/can/1.0/default/libc++fs/include/automotive/filesystem
index 660ad09745..bd3dda5518 100644
--- a/automotive/can/1.0/default/libc++fs/include/automotive/filesystem
+++ b/automotive/can/1.0/default/libc++fs/include/automotive/filesystem
@@ -9,6 +9,18 @@
 //===----------------------------------------------------------------------===//
 #ifndef _LIBAUTO_FILESYSTEM
 #define _LIBAUTO_FILESYSTEM
+
+// TODO(152067309): Remove this once the libc++ upgrade is complete.
+#include <__config>
+#if defined(_LIBCPP_VERSION) && _LIBCPP_VERSION > 8000
+
+#include <filesystem>
+namespace android::hardware::automotive {
+namespace filesystem = std::filesystem;
+}
+
+#else
+
 /*
     filesystem synopsis
 
@@ -2696,4 +2708,6 @@ end(const recursive_directory_iterator&) noexcept {
 
 _LIBCPP_POP_MACROS
 
+#endif  // defined(_LIBCPP_VERSION) && _LIBCPP_VERSION > 8000
+
 #endif // _LIBAUTO_FILESYSTEM
diff --git a/automotive/can/1.0/default/libc++fs/src/filesystem/directory_iterator.cpp b/automotive/can/1.0/default/libc++fs/src/filesystem/directory_iterator.cpp
index 37c863bfcb..0dbf492106 100644
--- a/automotive/can/1.0/default/libc++fs/src/filesystem/directory_iterator.cpp
+++ b/automotive/can/1.0/default/libc++fs/src/filesystem/directory_iterator.cpp
@@ -6,9 +6,15 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+
+// TODO(152067309): Remove this once the libc++ upgrade is complete.
+#include <__config>
+#if defined(_LIBCPP_VERSION) && _LIBCPP_VERSION <= 8000
+
 /* clang-format off */
 #include "automotive/filesystem"
 #include <__config>
+
 #if defined(_LIBCPP_WIN32API)
 #define WIN32_LEAN_AND_MEAN
 #include <Windows.h>
@@ -395,3 +401,5 @@ bool recursive_directory_iterator::__try_recursion(error_code* ec) {
 
 }  // namespace android::hardware::automotive::filesystem
 /* clang-format on */
+
+#endif // defined(_LIBCPP_VERSION) && _LIBCPP_VERSION <= 8000
diff --git a/automotive/can/1.0/default/libc++fs/src/filesystem/operations.cpp b/automotive/can/1.0/default/libc++fs/src/filesystem/operations.cpp
index 404c0bd4c9..6a76bdce55 100644
--- a/automotive/can/1.0/default/libc++fs/src/filesystem/operations.cpp
+++ b/automotive/can/1.0/default/libc++fs/src/filesystem/operations.cpp
@@ -6,6 +6,11 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+
+// TODO(152067309): Remove this once the libc++ upgrade is complete.
+#include <__config>
+#if defined(_LIBCPP_VERSION) && _LIBCPP_VERSION <= 8000
+
 /* clang-format off */
 #include "automotive/filesystem"
 #include <array>
@@ -1771,3 +1776,5 @@ error_code directory_entry::__do_refresh() noexcept {
 #endif
 }  // namespace android::hardware::automotive::filesystem
 /* clang-format on */
+
+#endif // defined(_LIBCPP_VERSION) && _LIBCPP_VERSION <= 8000