Fix libc++ issues #52 (outdated <filesystem>) and #49 (char8_t)

5 files changed, 26 insertions, 6 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5f400628..325a4c62 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -196,6 +196,14 @@ if(CMAKE_SYSTEM_NAME MATCHES "Linux")
   endif()
 endif()
 if(CMAKE_SYSTEM_NAME MATCHES "FreeBSD" OR APPLE)
+  if(CLANG_VERSION_MAJOR GREATER_EQUAL 9)
+    # Do nothing, it's built in
+  elseif(CLANG_VERSION_MAJOR GREATER_EQUAL 7)
+    find_library(libcxx_cxxfs c++fs)
+    all_link_libraries(PUBLIC ${libcxx_cxxfs})
+  endif()
+  # Link in experimental always. If library is in C++ 14, or older LLVM, experimental filesystem will be used.
+  # If libc++fs or built-in filesystem is used, this link will be discarded.
   find_library(libcxx_cxxexperimental c++experimental)
   all_link_libraries(PUBLIC ${libcxx_cxxexperimental})
 endif()
diff --git a/include/llfio/revision.hpp b/include/llfio/revision.hpp
index 04cb25f8..521885f8 100644
--- a/include/llfio/revision.hpp
+++ b/include/llfio/revision.hpp
@@ -1,4 +1,4 @@
 // Note the second line of this file must ALWAYS be the git SHA, third line ALWAYS the git SHA update time
-#define LLFIO_PREVIOUS_COMMIT_REF    e07bc7937d16c1cc84d92f7e809f1b37116f5e7f
-#define LLFIO_PREVIOUS_COMMIT_DATE   "2020-03-11 11:47:51 +00:00"
-#define LLFIO_PREVIOUS_COMMIT_UNIQUE e07bc793
+#define LLFIO_PREVIOUS_COMMIT_REF    c43ec836bce574fbd7b11203d021b6ee634cfed4
+#define LLFIO_PREVIOUS_COMMIT_DATE   "2020-03-13 11:24:11 +00:00"
+#define LLFIO_PREVIOUS_COMMIT_UNIQUE c43ec836
diff --git a/include/llfio/v2.0/config.hpp b/include/llfio/v2.0/config.hpp
index 3f9eb8d5..14dcc464 100644
--- a/include/llfio/v2.0/config.hpp
+++ b/include/llfio/v2.0/config.hpp
@@ -224,7 +224,9 @@ LLFIO_V2_NAMESPACE_END
 LLFIO_V2_NAMESPACE_BEGIN
 namespace filesystem = std::filesystem;
 LLFIO_V2_NAMESPACE_END
-#elif __has_include(<experimental/filesystem>) && (!defined(_MSC_VER) || _MSC_VER < 1923)  // C++ 14 filesystem support was dropped in VS2019 16.3
+// C++ 14 filesystem support was dropped in VS2019 16.3
+// C++ 14 filesystem support was dropped in LLVM 11
+#elif __has_include(<experimental/filesystem>) && (!defined(_MSC_VER) || _MSC_VER < 1923) && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 11000)  
 #include <experimental/filesystem>
 LLFIO_V2_NAMESPACE_BEGIN
 namespace filesystem = std::experimental::filesystem;
@@ -233,6 +235,9 @@ LLFIO_V2_NAMESPACE_END
 #if defined(_MSC_VER) && _MSC_VER >= 1923
 #error MSVC dropped support for C++ 14 <filesystem> from VS2019 16.3 onwards. Please enable C++ 17 or later.
 #endif
+#if defined(_LIBCPP_VERSION) && _LIBCPP_VERSION >= 11000
+#error libc++ dropped support for C++ 14 <filesystem> from LLVM 11 onwards. Please enable C++ 17 or later.
+#endif
 #include <filesystem>
 LLFIO_V2_NAMESPACE_BEGIN
 namespace filesystem = std::filesystem;
diff --git a/include/llfio/v2.0/detail/impl/path_view.ipp b/include/llfio/v2.0/detail/impl/path_view.ipp
index 84ddd40e..4e34b948 100644
--- a/include/llfio/v2.0/detail/impl/path_view.ipp
+++ b/include/llfio/v2.0/detail/impl/path_view.ipp
@@ -361,8 +361,14 @@ namespace detail
 #endif
 #else
 #if defined(_LIBCPP_VERSION)
-    // libc++ appears to be missing char8_t to wchar_t codecvt entirely
-    return _reencode_path_to(toallocate, dest_buffer, dest_buffer_length, (const char *) src_buffer, src_buffer_length);
+    // libc++ appears to be missing anything to wchar_t codecvt entirely
+    (void) toallocate;
+    (void) dest_buffer;
+    (void) dest_buffer_length;
+    (void) src_buffer;
+    (void) src_buffer_length;
+    LLFIO_LOG_FATAL(nullptr, "path_view_component::c_str reencoding function does not support char8_t to wchar_t conversion on libc++.");
+    abort();
 #else
     return _reencode_path_to(toallocate, dest_buffer, dest_buffer_length, src_buffer, src_buffer_length);
 #endif
diff --git a/release_notes.md b/release_notes.md
index 6b49e866..ad27c3fb 100644
--- a/release_notes.md
+++ b/release_notes.md
@@ -24,6 +24,7 @@ It is a complete rewrite after a Boost peer review in August 2015. Its github
 source code repository lives at https://github.com/ned14/llfio.
 
 - Portable to any conforming C++ 14 compiler with a working Filesystem TS in its STL.
+    - Note that VS2019 16.3 and libc++ 11 dropped support for Filesystem in C++ 14.
 - Will make use of any Concepts TS if you have them.
 - Provides view adapters into the Ranges TS, so ready for STL2.
 - Original error code is always preserved, even down to the original NT kernel error code if a NT kernel API was used.