path: root/clang/docs/ReleaseNotes.rst

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Clang |release| |ReleaseNotesTitle|
===========================================

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Written by the `LLVM Team <https://llvm.org/>`_

.. only:: PreRelease

  .. warning::
     These are in-progress notes for the upcoming Clang |version| release.
     Release notes for previous releases can be found on
     `the Releases Page <https://llvm.org/releases/>`_.

Introduction
============

This document contains the release notes for the Clang C/C++/Objective-C
frontend, part of the LLVM Compiler Infrastructure, release |release|. Here we
describe the status of Clang 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>`_. For the libc++ release notes,
see `this page <https://libcxx.llvm.org/ReleaseNotes.html>`_. All LLVM releases
may be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.

For more information about Clang or LLVM, including information about the
latest release, please see the `Clang Web Site <https://clang.llvm.org>`_ or the
`LLVM Web Site <https://llvm.org>`_.

Potentially Breaking Changes
============================
These changes are ones which we think may surprise users when upgrading to
Clang |release| because of the opportunity they pose for disruption to existing
code bases.

C/C++ Language Potentially Breaking Changes
-------------------------------------------

C++ Specific Potentially Breaking Changes
-----------------------------------------

ABI Changes in This Version
---------------------------

AST Dumping Potentially Breaking Changes
----------------------------------------

What's New in Clang |release|?
==============================
Some of the major new features and improvements to Clang are listed
here. Generic improvements to Clang as a whole or to its underlying
infrastructure are described first, followed by language-specific
sections with improvements to Clang's support for those languages.

C++ Language Changes
--------------------

C++20 Feature Support
^^^^^^^^^^^^^^^^^^^^^

- Clang won't perform ODR checks for decls in the global module fragment any
  more to ease the implementation and improve the user's using experience.
  This follows the MSVC's behavior.
  (`#79240 <https://github.com/llvm/llvm-project/issues/79240>`_).

C++23 Feature Support
^^^^^^^^^^^^^^^^^^^^^

C++2c Feature Support
^^^^^^^^^^^^^^^^^^^^^

- Implemented `P2662R3 Pack Indexing <https://wg21.link/P2662R3>`_.


Resolutions to C++ Defect Reports
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- Substitute template parameter pack, when it is not explicitly specified
  in the template parameters, but is deduced from a previous argument.
  (`#78449: <https://github.com/llvm/llvm-project/issues/78449>`_).

C Language Changes
------------------

C23 Feature Support
^^^^^^^^^^^^^^^^^^^

Non-comprehensive list of changes in this release
-------------------------------------------------

New Compiler Flags
------------------

Deprecated Compiler Flags
-------------------------

Modified Compiler Flags
-----------------------

Removed Compiler Flags
-------------------------

Attribute Changes in Clang
--------------------------

Improvements to Clang's diagnostics
-----------------------------------
- Clang now applies syntax highlighting to the code snippets it
  prints.

Improvements to Clang's time-trace
----------------------------------

Bug Fixes in This Version
-------------------------

Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Bug Fixes to Attribute Support
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Bug Fixes to C++ Support
^^^^^^^^^^^^^^^^^^^^^^^^

- Fix crash when using lifetimebound attribute in function with trailing return.
  Fixes (`#73619 <https://github.com/llvm/llvm-project/issues/73619>`_)
- Fix a crash when specializing an out-of-line member function with a default
  parameter where we did an incorrect specialization of the initialization of
  the default parameter.
  Fixes (`#68490 <https://github.com/llvm/llvm-project/issues/68490>`_)
- Fixed a bug where variables referenced by requires-clauses inside
  nested generic lambdas were not properly injected into the constraint scope.
  (`#73418 <https://github.com/llvm/llvm-project/issues/73418>`_)
- Fixed deducing auto& from const int in template parameters of partial
  specializations.
  (`#77189 <https://github.com/llvm/llvm-project/issues/77189>`_)

Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^

Miscellaneous Bug Fixes
^^^^^^^^^^^^^^^^^^^^^^^

Miscellaneous Clang Crashes Fixed
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

OpenACC Specific Changes
------------------------

Target Specific Changes
-----------------------

AMDGPU Support
^^^^^^^^^^^^^^

X86 Support
^^^^^^^^^^^

Arm and AArch64 Support
^^^^^^^^^^^^^^^^^^^^^^^

Android Support
^^^^^^^^^^^^^^^

Windows Support
^^^^^^^^^^^^^^^

LoongArch Support
^^^^^^^^^^^^^^^^^

RISC-V Support
^^^^^^^^^^^^^^

- ``__attribute__((rvv_vector_bits(N)))`` is now supported for RVV vbool*_t types.

CUDA/HIP Language Changes
^^^^^^^^^^^^^^^^^^^^^^^^^

CUDA Support
^^^^^^^^^^^^

AIX Support
^^^^^^^^^^^

WebAssembly Support
^^^^^^^^^^^^^^^^^^^

AVR Support
^^^^^^^^^^^

DWARF Support in Clang
----------------------

Floating Point Support in Clang
-------------------------------

AST Matchers
------------

clang-format
------------

libclang
--------

Static Analyzer
---------------

New features
^^^^^^^^^^^^

Crash and bug fixes
^^^^^^^^^^^^^^^^^^^

Improvements
^^^^^^^^^^^^

- Support importing C++20 modules in clang-repl.

Moved checkers
^^^^^^^^^^^^^^

.. _release-notes-sanitizers:

Sanitizers
----------

Python Binding Changes
----------------------

- Exposed `CXRewriter` API as `class Rewriter`.

Additional Information
======================

A wide variety of additional information is available on the `Clang web
page <https://clang.llvm.org/>`_. The web page contains versions of the
API documentation which are up-to-date with the Git version of
the source code. You can access versions of these documents specific to
this release by going into the "``clang/docs/``" directory in the Clang
tree.

If you have any questions or comments about Clang, please feel free to
contact us on the `Discourse forums (Clang Frontend category)
<https://discourse.llvm.org/c/clang/6>`_.