Implement <filesystem>

This patch implements the <filesystem> header and uses that
to provide <experimental/filesystem>.

Unlike other standard headers, the symbols needed for <filesystem>
have not yet been placed in libc++.so. Instead they live in the
new libc++fs.a library. Users of filesystem are required to link this
library. (Also note that libc++experimental no longer contains the
definition of <experimental/filesystem>, which now requires linking libc++fs).

The reason for keeping <filesystem> out of the dylib for now is that
it's still somewhat experimental, and the possibility of requiring an
ABI breaking change is very real. In the future the symbols will likely
be moved into the dylib, or the dylib will be made to link libc++fs automagically).

Note that moving the symbols out of libc++experimental may break user builds
until they update to -lc++fs. This should be OK, because the experimental
library provides no stability guarantees. However, I plan on looking into
ways we can force libc++experimental to automagically link libc++fs.

In order to use a single implementation and set of tests for <filesystem>, it
has been placed in a special `__fs` namespace. This namespace is inline in
C++17 onward, but not before that. As such implementation is available
in C++11 onward, but no filesystem namespace is present "directly", and
as such name conflicts shouldn't occur in C++11 or C++14.

llvm-svn: 338093

1 files changed, 2 insertions, 2 deletions

diff --git a/libcxx/www/cxx1z_status.html b/libcxx/www/cxx1z_status.html
index 3d826acf3b6..de8caa87f57 100644
--- a/libcxx/www/cxx1z_status.html
+++ b/libcxx/www/cxx1z_status.html
@@ -83,7 +83,7 @@
   	<tr><td></td><td></td><td></td><td></td><td></td><td></td></tr>
 	<tr><td><a href="https://wg21.link/P0024R2">P0024R2</a></td><td>LWG</td><td>The Parallelism TS Should be Standardized</td><td>Jacksonville</td><td></td><td></td></tr>
 	<tr><td><a href="https://wg21.link/P0226R1">P0226R1</a></td><td>LWG</td><td>Mathematical Special Functions for C++17</td><td>Jacksonville</td><td></td><td></td></tr>
-	<tr><td><a href="https://wg21.link/P0220R1">P0220R1</a></td><td>LWG</td><td>Adopt Library Fundamentals V1 TS Components for C++17</td><td>Jacksonville</td><td>In Progress</td><td></td></tr>
+	<tr><td><a href="https://wg21.link/P0220R1">P0220R1</a></td><td>LWG</td><td>Adopt Library Fundamentals V1 TS Components for C++17</td><td>Jacksonville</td><td>Complete</td><td>7.0</td></tr>
 	<tr><td><a href="https://wg21.link/P0218R1">P0218R1</a></td><td>LWG</td><td>Adopt the File System TS for C++17</td><td>Jacksonville</td><td>In Progress</td><td></td></tr>
 	<tr><td><a href="https://wg21.link/P0033R1">P0033R1</a></td><td>LWG</td><td>Re-enabling shared_from_this</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>
 	<tr><td><a href="https://wg21.link/P0005R4">P0005R4</a></td><td>LWG</td><td>Adopt not_fn from Library Fundamentals 2 for C++17</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>
@@ -443,7 +443,7 @@
 	<tr><td><a href="https://wg21.link/LWG2778">2778</a></td><td>basic_string_view is missing constexpr</td><td>Issaquah</td><td>Complete</td></tr>
  	<tr><td></td><td></td><td></td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2260">2260</a></td><td>Missing requirement for Allocator::pointer</td><td>Kona</td><td></td></tr>
-	<tr><td><a href="https://wg21.link/LWG2676">2676</a></td><td>Provide filesystem::path overloads for File-based streams</td><td>Kona</td><td></td></tr>
+	<tr><td><a href="https://wg21.link/LWG2676">2676</a></td><td>Provide filesystem::path overloads for File-based streams</td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2768">2768</a></td><td>any_cast and move semantics</td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2769">2769</a></td><td>Redundant const in the return type of any_cast(const any&amp;)</td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2781">2781</a></td><td>Contradictory requirements for std::function and std::reference_wrapper</td><td>Kona</td><td>Complete</td></tr>