[libc++] Remove <experimental/filesystem> header

[jloser]

Summary

<filesystem> header has been around for a while now, so we can safely remove
<experimental/filesystem> header. _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM
suggests we were going to remove <experimental/filesystem> in llvm 11 release,
but we never did. So, remove the experimental header now, its associated tests,
and the _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM macro.

[jloser]

Fix typo in release notes

[jloser]

First time seeing these CI failures, but they appear to be unrelated AFAICT.

[philnik]

If the libcxx CI passed it's all good.

[Mordante]

Thanks, this cleanups seems quite a bit overdue. LGTM with one nit.
The CI failures indeed seem unrelated, just make sure to keep an eye on it after landing or rebase to verify it's really unrelated.

libcxx/docs/ReleaseNotes.rst

50

[jloser]

In D119603#3316997, @Mordante wrote:

Thanks, this cleanups seems quite a bit overdue. LGTM with one nit.
The CI failures indeed seem unrelated, just make sure to keep an eye on it after landing or rebase to verify it's really unrelated.

I'll keep an eye on it tonight - just landed it and applied your comment on the release note for it.

[ldionne]

Pinging libc++ vendors just for awareness. This removal is according to our policy of removing TSes after the standardized feature has been shipped.

libcxx/docs/ReleaseNotes.rst

 API Changes
 -----------
 
 - The ``_LIBCPP_ABI_UNSTABLE`` macro has been removed in favour of setting
   ``_LIBCPP_ABI_VERSION=2``. This should not have any impact on users because
   they were not supposed to set ``_LIBCPP_ABI_UNSTABLE`` manually, however we
   still feel that it is worth mentioning in the release notes in case some users
   had been doing it.
+- The header ``<experimental/filesystem>`` has been removed. Instead, use
+  ``<filesystem>`` header. The associated macro
+  ``_LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM`` has also been removed.
 
 ABI Changes
 -----------
 
 - The ``_LIBCPP_ABI_USE_CXX03_NULLPTR_EMULATION`` macro controlling whether we use an
   emulation for ``std::nullptr_t`` in C++03 mode has been removed. After this change,
   ``_LIBCPP_ABI_USE_CXX03_NULLPTR_EMULATION`` will not be honoured anymore and there
   will be no way to opt back into the C++03 emulation of ``std::nullptr_t``.
 
 Build System Changes
 --------------------
 
 - Support for standalone builds have been entirely removed from libc++, libc++abi and
   libunwind. Please use :ref:`these instructions <build instructions>` for building
   libc++, libc++abi and/or libunwind.

libcxx/include/CMakeLists.txt

set(files
   errno.h
   exception
   execution
   experimental/__config
   experimental/__memory
   experimental/algorithm
   experimental/coroutine
   experimental/deque
-  experimental/filesystem
   experimental/forward_list
   experimental/functional
   experimental/iterator
   experimental/list
   experimental/map
   experimental/memory_resource
   experimental/propagate_const
   experimental/regex

libcxx/include/experimental/__config

 #define _LIBCPP_BEGIN_NAMESPACE_LFTS_V2 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v2 {
 #define _LIBCPP_END_NAMESPACE_LFTS_V2  } } }
 #define _VSTD_LFTS_V2 _VSTD_EXPERIMENTAL::fundamentals_v2
 
 #define _LIBCPP_BEGIN_NAMESPACE_LFTS_PMR _LIBCPP_BEGIN_NAMESPACE_LFTS namespace pmr {
 #define _LIBCPP_END_NAMESPACE_LFTS_PMR _LIBCPP_END_NAMESPACE_LFTS }
 #define _VSTD_LFTS_PMR _VSTD_LFTS::pmr
 
-#if defined(_LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_FILESYSTEM)
-#   define _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM /* nothing */
-#else
-#   define _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM __attribute__((deprecated("std::experimental::filesystem has now been deprecated in favor of C++17's std::filesystem. Please stop using it and start using std::filesystem. This experimental version will be removed in LLVM 11. You can remove this warning by defining the _LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_FILESYSTEM macro.")))
-#endif
-
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM \
-    _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace filesystem _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM { \
-    inline namespace v1 {
-
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM \
-    } } _LIBCPP_END_NAMESPACE_EXPERIMENTAL
-
 #if !defined(__cpp_coroutines) || __cpp_coroutines < 201703L
 #define _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #endif
 
 #define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_COROUTINES \
   _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace coroutines_v1 {
 
 #define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_COROUTINES \

libcxx/include/experimental/filesystem

-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// 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_EXPERIMENTAL_FILESYSTEM
-#define _LIBCPP_EXPERIMENTAL_FILESYSTEM
-/*
-    filesystem synopsis
-
-    namespace std { namespace experimental { namespace filesystem { inline namespace v1 {
-
-    class path;
-
-    void swap(path& lhs, path& rhs) noexcept;
-    size_t hash_value(const path& p) noexcept;
-
-    bool operator==(const path& lhs, const path& rhs) noexcept;
-    bool operator!=(const path& lhs, const path& rhs) noexcept;
-    bool operator< (const path& lhs, const path& rhs) noexcept;
-    bool operator<=(const path& lhs, const path& rhs) noexcept;
-    bool operator> (const path& lhs, const path& rhs) noexcept;
-    bool operator>=(const path& lhs, const path& rhs) noexcept;
-
-    path operator/ (const path& lhs, const path& rhs);
-
-    // fs.path.io operators are friends of path.
-    template <class charT, class traits>
-    friend basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os, const path& p);
-
-    template <class charT, class traits>
-    friend basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is, path& p);
-
-    template <class Source>
-      path u8path(const Source& source);
-    template <class InputIterator>
-      path u8path(InputIterator first, InputIterator last);
-
-    class filesystem_error;
-    class directory_entry;
-
-    class directory_iterator;
-
-    // enable directory_iterator range-based for statements
-    directory_iterator begin(directory_iterator iter) noexcept;
-    directory_iterator end(const directory_iterator&) noexcept;
-
-    class recursive_directory_iterator;
-
-    // enable recursive_directory_iterator range-based for statements
-    recursive_directory_iterator begin(recursive_directory_iterator iter) noexcept;
-    recursive_directory_iterator end(const recursive_directory_iterator&) noexcept;
-
-    class file_status;
-
-    struct space_info
-    {
-      uintmax_t capacity;
-      uintmax_t free;
-      uintmax_t available;
-    };
-
-    enum class file_type;
-    enum class perms;
-    enum class perm_options;
-    enum class copy_options;
-    enum class directory_options;
-
-    typedef chrono::time_point<trivial-clock>  file_time_type;
-
-    // operational functions
-
-    path absolute(const path& p);
-    path absolute(const path& p, error_code &ec);
-
-    path canonical(const path& p);
-    path canonical(const path& p, error_code& ec);
-
-    void copy(const path& from, const path& to);
-    void copy(const path& from, const path& to, error_code& ec);
-    void copy(const path& from, const path& to, copy_options options);
-    void copy(const path& from, const path& to, copy_options options,
-                   error_code& ec);
-
-    bool copy_file(const path& from, const path& to);
-    bool copy_file(const path& from, const path& to, error_code& ec);
-    bool copy_file(const path& from, const path& to, copy_options option);
-    bool copy_file(const path& from, const path& to, copy_options option,
-                           error_code& ec);
-
-    void copy_symlink(const path& existing_symlink, const path& new_symlink);
-    void copy_symlink(const path& existing_symlink, const path& new_symlink,
-                              error_code& ec) noexcept;
-
-    bool create_directories(const path& p);
-    bool create_directories(const path& p, error_code& ec);
-
-    bool create_directory(const path& p);
-    bool create_directory(const path& p, error_code& ec) noexcept;
-
-    bool create_directory(const path& p, const path& attributes);
-    bool create_directory(const path& p, const path& attributes,
-                                  error_code& ec) noexcept;
-
-    void create_directory_symlink(const path& to, const path& new_symlink);
-    void create_directory_symlink(const path& to, const path& new_symlink,
-                                          error_code& ec) noexcept;
-
-    void create_hard_link(const path& to, const path& new_hard_link);
-    void create_hard_link(const path& to, const path& new_hard_link,
-                                  error_code& ec) noexcept;
-
-    void create_symlink(const path& to, const path& new_symlink);
-    void create_symlink(const path& to, const path& new_symlink,
-                                error_code& ec) noexcept;
-
-    path current_path();
-    path current_path(error_code& ec);
-    void current_path(const path& p);
-    void current_path(const path& p, error_code& ec) noexcept;
-
-    bool exists(file_status s) noexcept;
-    bool exists(const path& p);
-    bool exists(const path& p, error_code& ec) noexcept;
-
-    bool equivalent(const path& p1, const path& p2);
-    bool equivalent(const path& p1, const path& p2, error_code& ec) noexcept;
-
-    uintmax_t    file_size(const path& p);
-    uintmax_t    file_size(const path& p, error_code& ec) noexcept;
-
-    uintmax_t    hard_link_count(const path& p);
-    uintmax_t    hard_link_count(const path& p, error_code& ec) noexcept;
-
-    bool is_block_file(file_status s) noexcept;
-    bool is_block_file(const path& p);
-    bool is_block_file(const path& p, error_code& ec) noexcept;
-
-    bool is_character_file(file_status s) noexcept;
-    bool is_character_file(const path& p);
-    bool is_character_file(const path& p, error_code& ec) noexcept;
-
-    bool is_directory(file_status s) noexcept;
-    bool is_directory(const path& p);
-    bool is_directory(const path& p, error_code& ec) noexcept;
-
-    bool is_empty(const path& p);
-    bool is_empty(const path& p, error_code& ec) noexcept;
-
-    bool is_fifo(file_status s) noexcept;
-    bool is_fifo(const path& p);
-    bool is_fifo(const path& p, error_code& ec) noexcept;
-
-    bool is_other(file_status s) noexcept;
-    bool is_other(const path& p);
-    bool is_other(const path& p, error_code& ec) noexcept;
-
-    bool is_regular_file(file_status s) noexcept;
-    bool is_regular_file(const path& p);
-    bool is_regular_file(const path& p, error_code& ec) noexcept;
-
-    bool is_socket(file_status s) noexcept;
-    bool is_socket(const path& p);
-    bool is_socket(const path& p, error_code& ec) noexcept;
-
-    bool is_symlink(file_status s) noexcept;
-    bool is_symlink(const path& p);
-    bool is_symlink(const path& p, error_code& ec) noexcept;
-
-    file_time_type  last_write_time(const path& p);
-    file_time_type  last_write_time(const path& p, error_code& ec) noexcept;
-    void last_write_time(const path& p, file_time_type new_time);
-    void last_write_time(const path& p, file_time_type new_time,
-                                 error_code& ec) noexcept;
-
-    void permissions(const path& p, perms prms,
-                     perm_options opts=perm_options::replace);
-    void permissions(const path& p, perms prms, error_code& ec) noexcept;
-    void permissions(const path& p, perms prms, perm_options opts,
-                     error_code& ec);
-
-    path proximate(const path& p, error_code& ec);
-    path proximate(const path& p, const path& base = current_path());
-    path proximate(const path& p, const path& base, error_code &ec);
-
-    path read_symlink(const path& p);
-    path read_symlink(const path& p, error_code& ec);
-
-    path relative(const path& p, error_code& ec);
-    path relative(const path& p, const path& base=current_path());
-    path relative(const path& p, const path& base, error_code& ec);
-
-    bool remove(const path& p);
-    bool remove(const path& p, error_code& ec) noexcept;
-
-    uintmax_t    remove_all(const path& p);
-    uintmax_t    remove_all(const path& p, error_code& ec);
-
-    void rename(const path& from, const path& to);
-    void rename(const path& from, const path& to, error_code& ec) noexcept;
-
-    void resize_file(const path& p, uintmax_t size);
-    void resize_file(const path& p, uintmax_t size, error_code& ec) noexcept;
-
-    space_info   space(const path& p);
-    space_info   space(const path& p, error_code& ec) noexcept;
-
-    file_status  status(const path& p);
-    file_status  status(const path& p, error_code& ec) noexcept;
-
-    bool status_known(file_status s) noexcept;
-
-    file_status  symlink_status(const path& p);
-    file_status  symlink_status(const path& p, error_code& ec) noexcept;
-
-    path temp_directory_path();
-    path temp_directory_path(error_code& ec);
-
-    path weakly_canonical(path const& p);
-    path weakly_canonical(path const& p, error_code& ec);
-
-
-} } } }  // namespaces std::experimental::filesystem::v1
-
-*/
-
-#include <experimental/__config>
-#include <filesystem>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#ifndef _LIBCPP_CXX03_LANG
-
-#define __cpp_lib_experimental_filesystem 201406
-
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM
-
-using namespace _VSTD_FS;
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM
-
-#endif // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_EXPERIMENTAL_FILESYSTEM

libcxx/include/module.modulemap

module coroutine {
       requires coroutines
       header "experimental/coroutine"
       export *
     }
     module deque {
       header "experimental/deque"
       export *
     }
-    module filesystem {
-      header "experimental/filesystem"
-      export *
-    }
     module forward_list {
       header "experimental/forward_list"
       export *
     }
     module functional {
       header "experimental/functional"
       export *
     }

libcxx/test/libcxx/double_include.sh.cpp

 
 // experimental headers
 #if __cplusplus >= 201103L
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
 #    endif
 #    include <experimental/deque>
-#    ifndef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY
-#        include <experimental/filesystem>
-#    endif
 #    include <experimental/forward_list>
 #    include <experimental/functional>
 #    include <experimental/iterator>
 #    include <experimental/list>
 #    include <experimental/map>
 #    include <experimental/memory_resource>
 #    include <experimental/propagate_const>
 #    ifndef _LIBCPP_HAS_NO_LOCALIZATION

libcxx/test/libcxx/experimental/filesystem/deprecated.verify.cpp

-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03
-// UNSUPPORTED: libcpp-has-no-filesystem-library
-
-// <experimental/filesystem>
-
-#include <experimental/filesystem>
-
-using namespace std::experimental::filesystem; // expected-warning {{'filesystem' is deprecated: std::experimental::filesystem has now been deprecated in favor of C++17's std::filesystem. Please stop using it and start using std::filesystem. This experimental version will be removed in LLVM 11. You can remove this warning by defining the _LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_FILESYSTEM macro.}}
-
-int main(int, char**) {
-  return 0;
-}

libcxx/test/libcxx/experimental/filesystem/version.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: libcpp-has-no-filesystem-library
-
-// <experimental/filesystem>
-
-#define _LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_FILESYSTEM
-
-#include <experimental/filesystem>
-
-#include "test_macros.h"
-
-#ifndef _LIBCPP_VERSION
-#error _LIBCPP_VERSION not defined
-#endif
-
-int main(int, char**)
-{
-
-  return 0;
-}

libcxx/test/libcxx/min_max_macros.compile.pass.cpp

 #    include <experimental/algorithm>
 TEST_MACROS();
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
 TEST_MACROS();
 #    endif
 #    include <experimental/deque>
 TEST_MACROS();
-#    ifndef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY
-#        include <experimental/filesystem>
-TEST_MACROS();
-#    endif
 #    include <experimental/forward_list>
 TEST_MACROS();
 #    include <experimental/functional>
 TEST_MACROS();
 #    include <experimental/iterator>
 TEST_MACROS();
 #    include <experimental/list>
 TEST_MACROS();

libcxx/test/libcxx/nasty_macros.compile.pass.cpp

 
 // experimental headers
 #if __cplusplus >= 201103L
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
 #    endif
 #    include <experimental/deque>
-#    ifndef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY
-#        include <experimental/filesystem>
-#    endif
 #    include <experimental/forward_list>
 #    include <experimental/functional>
 #    include <experimental/iterator>
 #    include <experimental/list>
 #    include <experimental/map>
 #    include <experimental/memory_resource>
 #    include <experimental/propagate_const>
 #    ifndef _LIBCPP_HAS_NO_LOCALIZATION

libcxx/test/libcxx/no_assert_include.compile.pass.cpp

 
 // experimental headers
 #if __cplusplus >= 201103L
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
 #    endif
 #    include <experimental/deque>
-#    ifndef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY
-#        include <experimental/filesystem>
-#    endif
 #    include <experimental/forward_list>
 #    include <experimental/functional>
 #    include <experimental/iterator>
 #    include <experimental/list>
 #    include <experimental/map>
 #    include <experimental/memory_resource>
 #    include <experimental/propagate_const>
 #    ifndef _LIBCPP_HAS_NO_LOCALIZATION

libcxx/test/std/experimental/filesystem/fs.req.macros/feature_macro.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: libcpp-has-no-filesystem-library
-
-// <experimental/filesystem>
-
-// #define __cpp_lib_experimental_filesystem 201406L
-
-#include <experimental/filesystem>
-#include "test_macros.h"
-
-#if TEST_STD_VER >= 11
-#ifndef __cpp_lib_experimental_filesystem
-#error Filesystem feature test macro is not defined  (__cpp_lib_experimental_filesystem)
-#elif __cpp_lib_experimental_filesystem != 201406L
-#error Filesystem feature test macro has an incorrect value (__cpp_lib_experimental_filesystem)
-#endif
-#else // TEST_STD_VER < 11
-#ifdef __cpp_lib_experimental_filesystem
-#error Filesystem feature test macro should not be defined in c++03
-#endif
-#endif
-
-int main(int, char**) {
-  return 0;
-}

libcxx/test/std/experimental/filesystem/fs.req.namespace/namespace.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03
-// UNSUPPORTED: libcpp-has-no-filesystem-library
-
-// <experimental/filesystem>
-
-// namespace std::experimental::filesystem::v1
-
-#include <experimental/filesystem>
-#include <type_traits>
-
-#include "test_macros.h"
-
-int main(int, char**) {
-  static_assert(std::is_same<
-          std::experimental::filesystem::path,
-          std::experimental::filesystem::v1::path
-      >::value, "");
-
-  return 0;
-}

libcxx/utils/generate_header_tests.py

header_markup = {
     "barrier": ["ifndef _LIBCPP_HAS_NO_THREADS"],
     "future": ["ifndef _LIBCPP_HAS_NO_THREADS"],
     "latch": ["ifndef _LIBCPP_HAS_NO_THREADS"],
     "mutex": ["ifndef _LIBCPP_HAS_NO_THREADS"],
     "semaphore": ["ifndef _LIBCPP_HAS_NO_THREADS"],
     "shared_mutex": ["ifndef _LIBCPP_HAS_NO_THREADS"],
     "thread": ["ifndef _LIBCPP_HAS_NO_THREADS"],
 
-    "experimental/filesystem": ["ifndef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY"],
     "filesystem": ["ifndef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY"],
     "format": ["ifndef _LIBCPP_HAS_NO_INCOMPLETE_FORMAT"],
 
     "clocale": ["ifndef _LIBCPP_HAS_NO_LOCALIZATION"],
     "codecvt": ["ifndef _LIBCPP_HAS_NO_LOCALIZATION"],
     "fstream": ["ifndef _LIBCPP_HAS_NO_LOCALIZATION"],
     "iomanip": ["ifndef _LIBCPP_HAS_NO_LOCALIZATION"],
     "ios": ["ifndef _LIBCPP_HAS_NO_LOCALIZATION"],

llvm/utils/gn/secondary/libcxx/include/BUILD.gn

sources = [
       "errno.h",
       "exception",
       "execution",
       "experimental/__config",
       "experimental/__memory",
       "experimental/algorithm",
       "experimental/coroutine",
       "experimental/deque",
-      "experimental/filesystem",
       "experimental/forward_list",
       "experimental/functional",
       "experimental/iterator",
       "experimental/list",
       "experimental/map",
       "experimental/memory_resource",
       "experimental/propagate_const",
       "experimental/regex",