[libcxx-commits] [libcxx] [libc++][doc] Removes LLVM-17 release notes. (PR #78062)
via libcxx-commits
libcxx-commits at lists.llvm.org
Sat Jan 13 11:11:21 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxx
Author: Mark de Wever (mordante)
<details>
<summary>Changes</summary>
The old notes are kept to make it easier to backport changes to the release branch. There are no LLVM-17 releases expected and this documentation should not be available in the LLVM-18 release.
Note after branching LLVM-18 both LLVM-18 and LLVM-19 release notes should be available.
---
Full diff: https://github.com/llvm/llvm-project/pull/78062.diff
2 Files Affected:
- (removed) libcxx/docs/ReleaseNotes/17.rst (-234)
- (modified) libcxx/docs/index.rst (-1)
``````````diff
diff --git a/libcxx/docs/ReleaseNotes/17.rst b/libcxx/docs/ReleaseNotes/17.rst
deleted file mode 100644
index 763dc3494ebfc7..00000000000000
--- a/libcxx/docs/ReleaseNotes/17.rst
+++ /dev/null
@@ -1,234 +0,0 @@
-============================
-Libc++ 17.0.0 Release Notes
-============================
-
-.. contents::
- :local:
- :depth: 2
-
-Written by the `Libc++ Team <https://libcxx.llvm.org>`_
-
-Introduction
-============
-
-This document contains the release notes for the libc++ C++ Standard Library,
-part of the LLVM Compiler Infrastructure, release 17.0.0. Here we describe the
-status of libc++ in some detail, including major improvements from the previous
-release and new feature work. For the general LLVM release notes, see `the LLVM
-documentation <https://llvm.org/docs/ReleaseNotes.html>`_. All LLVM releases may
-be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.
-
-For more information about libc++, please see the `Libc++ Web Site
-<https://libcxx.llvm.org>`_ or the `LLVM Web Site <https://llvm.org>`_.
-
-Note that if you are reading this file from a Git checkout or the
-main Libc++ web page, this document applies to the *next* release, not
-the current one. To see the release notes for a specific release, please
-see the `releases page <https://llvm.org/releases/>`_.
-
-What's New in Libc++ 17.0.0?
-============================
-
-The main focus of the libc++ team has been to implement new C++20 and C++23
-features. Work on the next C++ version, C++26, has started.
-
-The C++20 ``format`` library is marked as stable. The library is not complete since
-the C++20 ``chrono`` library lacks supports for time zones and some clocks.
-
-The C++20 spaceship operator is almost complete. It misses ``long double`` and
-time zone support.
-
-There is an experimental implementation of the C++23 ``std`` module. See
-:ref:`ModulesInLibcxx` for more information.
-
-An experimental implementation of the C++20 ``stop_token`` is available.
-
-Work has started on the C++17 Parallel STL. This feature is experimental, see
-:ref:`pstl-status` for the current status.
-
-
-Implemented Papers
-------------------
-- P1206R7 - ``ranges::to``: A function to convert any range to a container
-- P2520R0 - ``move_iterator<T*>`` should be a random access iterator
-- P1328R1 - ``constexpr type_info::operator==()``
-- P2693R1 - Formatting ``thread::id`` (the ``stacktrace`` is not done yet)
-- P2675R1 - ``format``'s width estimation is too approximate and not forward compatible
-- P2505R5 - Monadic operations for ``std::expected``
-- P2711R1 - Making Multi-Param Constructors Of views explicit (``join_with_view`` is not done yet)
-- P2572R1 - ``std::format`` fill character allowances
-- P2510R3 - Formatting pointers
-- P2136R3 - ``invoke_r``
-- P2494R2 - Relaxing range adaptors to allow for move only types
-- P2585R0 - Improving default container formatting
-- P0408R7 - Efficient Access to ``basic_stringbuf``'s Buffer
-- P2474R2 - ``views::repeat``
-- P0009R18 - ``mdspan`` (``layout_stride`` is not done yet)
-- P2093R14 - Formatted output (the ``ostream`` overload is not done yet)
-- P2539R4 - Should the output of ``std::print`` to a terminal be synchronized
- with the underlying stream? (the ``ostream`` overload is not done yet)
-
-With the ``format`` library being marked as stable, the
-following papers are now available by default without using
-``-fexperimental-library``:
-
-- P0645 - Text Formatting
-- P1652 - Printf corner cases in std::format
-- P1892 - Extended locale-specific presentation specifiers for std::format
-- P1868 - width: clarifying units of width and precision in std::format
-- P2216 - std::format improvements
-- P2418 - Add support for std::generator-like types to std::format
-- P2286R8 - Formatting Ranges
-- P2508R1 - Exposing std::basic-format-string
-
-Improvements and New Features
------------------------------
-- ``std::equal``, ``std::ranges::equal``, ``std::find``, and
- ``std::ranges::find`` are now forwarding to ``std::memcmp`` for trivially
- equality comparable types, which can lead up to 40x performance improvements.
-
-- The performance of ``dynamic_cast`` on its hot paths is greatly improved and is as efficient as the
- ``libsupc++`` implementation. Note that the performance improvements are shipped in ``libcxxabi``.
-
-- `D122780 <https://reviews.llvm.org/D122780>`_ Improved the performance of ``std::sort`` and ``std::ranges::sort``
- by up to 50% for arithmetic types and by approximately 10% for other types.
-
-- The ``<format>`` header is no longer considered experimental. Some
- ``std::formatter`` specializations are not yet available since the class used
- in the specialization has not been implemented in libc++. This prevents the
- feature-test macro to be set.
-
-- Platforms that don't have support for a filesystem can now still take advantage of some parts of ``<filesystem>``.
- Anything that does not rely on having an actual filesystem available will now work, such as ``std::filesystem::path``,
- ``std::filesystem::perms`` and similar classes.
-
-- ASan container annotations have been extended to cover all allocators in ``std::vector``.
-
-- ASan annotations have been added to the ``std::deque`` container, to detect container overflows.
-
-- On Windows, ``std::wcout``, ``wcin``, and ``wcerr`` now work correctly when the underlying
- stream has been configured in wide mode.
-
-Deprecations and Removals
--------------------------
-
-- The legacy debug mode has been removed in this release. The ``LIBCXX_ENABLE_DEBUG_MODE`` CMake variable has been
- removed. For additional context, refer to the `Discourse post
- <https://discourse.llvm.org/t/rfc-removing-the-legacy-debug-mode-from-libc/71026>`_.
-
-- The ``<experimental/coroutine>`` header has been removed in this release. The ``<coroutine>`` header
- has been shipping since LLVM 14, so the Coroutines TS implementation is being removed per our policy
- for removing TSes.
-
-- Several incidental transitive includes have been removed from libc++. Those
- includes are removed based on the language version used. Incidental transitive
- inclusions of the following headers have been removed:
-
- - C++23: ``atomic``, ``bit``, ``cstdint``, ``cstdlib``, ``cstring``, ``initializer_list``, ``limits``, ``new``,
- ``stdexcept``, ``system_error``, ``type_traits``, ``typeinfo``
-
- - ``<algorithm>`` no longer includes ``<chrono>`` in any C++ version (it was previously included in C++17 and earlier).
-
- - ``<string>`` no longer includes ``<vector>`` in any C++ version (it was previously included in C++20 and earlier).
-
- - ``<string>``, ``<string_view>``, and ``<mutex>`` no longer include ``<functional>``
- in any C++ version (it was previously included in C++20 and earlier).
-
-- ``<atomic>``, ``<barrier>``, ``<latch>``, ``<numeric>``, ``<semaphore>`` and ``<shared_mutex>`` no longer include ``<iosfwd>``
- (it was previously included in all Standard versions).
-
-- ``<format>``, ``<chrono>`` and ``<thread>`` no longer transitively include ``<cstdlib>``.
-
-- The headers ``<experimental/algorithm>`` and ``<experimental/functional>`` have been removed, since all the contents
- have been implemented in namespace ``std`` for at least two releases.
-
-- The ``std`` clang module has been broken up into separate top level modules per public header.
-
-- The formatter specialization ``template<size_t N> struct formatter<const charT[N], charT>``
- has been removed. Since libc++'s format library was marked experimental there
- is no backwards compatibility option. This specialization has been removed
- from the Standard since it was never used, the proper specialization to use
- instead is ``template<size_t N> struct formatter<charT[N], charT>``.
-
-- Libc++ used to provide some C++11 tag type global variables in C++03 as an extension, which are removed in
- this release. Those variables were ``std::allocator_arg``, ``std::defer_lock``, ``std::try_to_lock``,
- ``std::adopt_lock``, and ``std::piecewise_construct``. Note that the types associated to those variables are
- still provided in C++03 as an extension (e.g. ``std::piecewise_construct_t``). Providing those variables in
- C++03 mode made it impossible to define them properly -- C++11 mandated that they be ``constexpr`` variables,
- which is impossible in C++03 mode. Furthermore, C++17 mandated that they be ``inline constexpr`` variables,
- which led to ODR violations when mixed with the C++03 definition. Cleaning this up is required for libc++ to
- make progress on support for C++20 modules.
-
-- The ``_LIBCPP_ABI_OLD_LOGNORMAL_DISTRIBUTION`` macro has been removed.
-
-- The classes ``strstreambuf`` , ``istrstream``, ``ostrstream``, and ``strstream`` have been deprecated.
- They have been deprecated in the Standard since C++98, but were never marked as deprecated in libc++.
-
-- LWG3631 ``basic_format_arg(T&&) should use remove_cvref_t<T> throughout`` removed
- support for ``volatile`` qualified formatters.
-
-- The unmaintained Solaris support has been removed.
-
-Upcoming Deprecations and Removals
-----------------------------------
-
-LLVM 18
-~~~~~~~
-
-- The base template for ``std::char_traits`` has been marked as deprecated and
- will be removed in LLVM 18. If you are using ``std::char_traits`` with types
- other than ``char``, ``wchar_t``, ``char8_t``, ``char16_t``, ``char32_t`` or
- a custom character type for which you specialized ``std::char_traits``, your code
- will stop working when we remove the base template. The Standard does not
- mandate that a base template is provided, and such a base template is bound
- to be incorrect for some types, which could currently cause unexpected
- behavior while going undetected.
-
-- The ``_LIBCPP_AVAILABILITY_CUSTOM_VERBOSE_ABORT_PROVIDED`` macro will not be honored anymore in LLVM 18.
- Please see the updated documentation about the safe libc++ mode and in particular the ``_LIBCPP_VERBOSE_ABORT``
- macro for details.
-
-- The headers ``<experimental/deque>``, ``<experimental/forward_list>``, ``<experimental/list>``,
- ``<experimental/map>``, ``<experimental/memory_resource>``, ``<experimental/regex>``, ``<experimental/set>``,
- ``<experimental/string>``, ``<experimental/unordered_map>``, ``<experimental/unordered_set>``,
- and ``<experimental/vector>`` will be removed in LLVM 18, as all their contents will have been implemented in
- namespace ``std`` for at least two releases.
-
-API Changes
------------
-- Added ``__asan_annotate_container_with_allocator``, which is a
- customization point to allow users to disable Address Sanitizer container annotations
- for specific allocators. See :ref:`turning-off-asan` for more
- information.
-
-ABI Affecting Changes
----------------------
-
-- Symbols for ``std::allocator_arg``, ``std::defer_lock``, ``std::try_to_lock``, ``std::adopt_lock``, and
- ``std::piecewise_construct`` have been removed from the built library. Under most circumstances, user code
- should not have been relying on those symbols anyway since those are empty classes and the compiler does
- not generate an undefined reference unless the address of the object is taken. However, this is an ABI break
- if the address of one of these objects has been taken in code compiled as C++03, since in those cases the
- objects were marked as defined in the shared library. In other Standard modes, this should never be a problem
- since those objects were defined in the headers as ``constexpr``.
-
-Build System Changes
---------------------
-
-- Building libc++ and libc++abi for Apple platforms now requires targeting macOS 10.13 and later.
- This is relevant for vendors building the libc++ shared library and for folks statically linking
- libc++ into an application that has back-deployment requirements on Apple platforms.
-
-- ``LIBCXX_ENABLE_FILESYSTEM`` now represents whether a filesystem is supported on the platform instead
- of representing merely whether ``<filesystem>`` should be provided. This means that vendors building
- with ``LIBCXX_ENABLE_FILESYSTEM=OFF`` will now also get ``<fstream>`` excluded from their configuration
- of the library.
-
-- ``LIBCXX_ENABLE_FSTREAM`` is not supported anymore, please use ``LIBCXX_ENABLE_FILESYSTEM=OFF`` if your
- platform does not have support for a filesystem.
-
-- The lit test parameter ``enable_modules`` changed from a Boolean to an enum. The changes are
-
- - ``False`` became ``none``. This option does not test with modules enabled.
- - ``True`` became ``clang``. This option tests using Clang modules.
- - ``std`` is a new optional and tests with the experimental C++23 ``std`` module.
diff --git a/libcxx/docs/index.rst b/libcxx/docs/index.rst
index 241eeba21bbe50..066d8d87e5526e 100644
--- a/libcxx/docs/index.rst
+++ b/libcxx/docs/index.rst
@@ -34,7 +34,6 @@ Getting Started with libc++
.. toctree::
:maxdepth: 1
- ReleaseNotes/17
ReleaseNotes/18
UsingLibcxx
BuildingLibcxx
``````````
</details>
https://github.com/llvm/llvm-project/pull/78062
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