forked from OSchip/llvm-project
254 lines
7.5 KiB
ReStructuredText
254 lines
7.5 KiB
ReStructuredText
===========================================
|
|
Clang |release| |ReleaseNotesTitle|
|
|
===========================================
|
|
|
|
.. contents::
|
|
:local:
|
|
:depth: 2
|
|
|
|
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 Download Page <https://releases.llvm.org/download.html>`_.
|
|
|
|
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>`_. 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>`_.
|
|
|
|
Note that if you are reading this file from a Git checkout or the
|
|
main Clang 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 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.
|
|
|
|
Major New Features
|
|
------------------
|
|
|
|
- Clang now supports the ``-fzero-call-used-regs`` feature for x86. The purpose
|
|
of this feature is to limit Return-Oriented Programming (ROP) exploits and
|
|
information leakage. It works by zeroing out a selected class of registers
|
|
before function return --- e.g., all GPRs that are used within the function.
|
|
There is an analogous ``zero_call_used_regs`` attribute to allow for finer
|
|
control of this feature.
|
|
|
|
Bug Fixes
|
|
------------------
|
|
- ``CXXNewExpr::getArraySize()`` previously returned a ``llvm::Optional``
|
|
wrapping a ``nullptr`` when the ``CXXNewExpr`` did not have an array
|
|
size expression. This was fixed and ``::getArraySize()`` will now always
|
|
either return ``None`` or a ``llvm::Optional`` wrapping a valid ``Expr*``.
|
|
This fixes `Issue 53742 <https://github.com/llvm/llvm-project/issues/53742>`_.
|
|
|
|
Improvements to Clang's diagnostics
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
Non-comprehensive list of changes in this release
|
|
-------------------------------------------------
|
|
|
|
New Compiler Flags
|
|
------------------
|
|
|
|
Deprecated Compiler Flags
|
|
-------------------------
|
|
|
|
Modified Compiler Flags
|
|
-----------------------
|
|
|
|
Removed Compiler Flags
|
|
-------------------------
|
|
|
|
New Pragmas in Clang
|
|
--------------------
|
|
|
|
- ...
|
|
|
|
Attribute Changes in Clang
|
|
--------------------------
|
|
|
|
- Added support for parameter pack expansion in `clang::annotate`.
|
|
|
|
- The ``overloadable`` attribute can now be written in all of the syntactic
|
|
locations a declaration attribute may appear.
|
|
This fixes `Issue 53805 <https://github.com/llvm/llvm-project/issues/53805>`_.
|
|
|
|
Windows Support
|
|
---------------
|
|
|
|
- Add support for MSVC-compatible ``/JMC``/``/JMC-`` flag in clang-cl (supports
|
|
X86/X64/ARM/ARM64). ``/JMC`` could only be used when ``/Zi`` or ``/Z7`` is
|
|
turned on. With this addition, clang-cl can be used in Visual Studio for the
|
|
JustMyCode feature. Note, you may need to manually add ``/JMC`` as additional
|
|
compile options in the Visual Studio since it currently assumes clang-cl does not support ``/JMC``.
|
|
|
|
C Language Changes in Clang
|
|
---------------------------
|
|
|
|
C2x Feature Support
|
|
-------------------
|
|
|
|
- Implemented `WG14 N2674 The noreturn attribute <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2764.pdf>`_.
|
|
|
|
C++ Language Changes in Clang
|
|
-----------------------------
|
|
|
|
- ...
|
|
|
|
C++20 Feature Support
|
|
^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
C++2b Feature Support
|
|
^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
- Implemented `P2128R6: Multidimensional subscript operator <https://wg21.link/P2128R6>`_.
|
|
- Implemented `P0849R8: auto(x): decay-copy in the language <https://wg21.link/P0849R8>`_.
|
|
|
|
CUDA Language Changes in Clang
|
|
------------------------------
|
|
|
|
Objective-C Language Changes in Clang
|
|
-------------------------------------
|
|
|
|
OpenCL C Language Changes in Clang
|
|
----------------------------------
|
|
|
|
...
|
|
|
|
ABI Changes in Clang
|
|
--------------------
|
|
|
|
OpenMP Support in Clang
|
|
-----------------------
|
|
|
|
- ``clang-nvlink-wrapper`` tool introduced to support linking of cubin files
|
|
archived in an archive. See :doc:`ClangNvlinkWrapper`.
|
|
- ``clang-linker-wrapper`` tool introduced to support linking using a new OpenMP
|
|
target offloading method. See :doc:`ClangLinkerWrapper`.
|
|
- Support for a new driver for OpenMP target offloading has been added as an
|
|
opt-in feature. The new driver can be selected using ``-fopenmp-new-driver``
|
|
with clang. Device-side LTO can also be enabled using the new driver by
|
|
passing ``-foffload-lto=`` as well. The new driver supports the following
|
|
features:
|
|
- Linking AMDGPU and NVPTX offloading targets.
|
|
- Static linking using archive files.
|
|
- Device-side LTO.
|
|
|
|
CUDA Support in Clang
|
|
---------------------
|
|
|
|
- ...
|
|
|
|
X86 Support in Clang
|
|
--------------------
|
|
|
|
DWARF Support in Clang
|
|
----------------------
|
|
|
|
Arm and AArch64 Support in Clang
|
|
--------------------------------
|
|
|
|
Floating Point Support in Clang
|
|
-------------------------------
|
|
|
|
Internal API Changes
|
|
--------------------
|
|
|
|
- Added a new attribute flag `AcceptsExprPack` that when set allows expression
|
|
pack expansions in the parsed arguments of the corresponding attribute.
|
|
Additionally it introduces delaying of attribute arguments, adding common
|
|
handling for creating attributes that cannot be fully initialized prior to
|
|
template instantiation.
|
|
|
|
Build System Changes
|
|
--------------------
|
|
|
|
AST Matchers
|
|
------------
|
|
|
|
- Expanded ``isInline`` narrowing matcher to support c++17 inline variables.
|
|
|
|
clang-format
|
|
------------
|
|
|
|
- **Important change**: Renamed ``IndentRequires`` to ``IndentRequiresClause``
|
|
and changed the default for all styles from ``false`` to ``true``.
|
|
|
|
- Reworked and improved handling of concepts and requires. Added the
|
|
``RequiresClausePosition`` option as part of that.
|
|
|
|
- Changed ``BreakBeforeConceptDeclarations`` from ``Boolean`` to an enum.
|
|
|
|
- Option ``InsertBraces`` has been added to insert optional braces after control
|
|
statements.
|
|
|
|
libclang
|
|
--------
|
|
|
|
- ...
|
|
|
|
Static Analyzer
|
|
---------------
|
|
|
|
- ...
|
|
|
|
.. _release-notes-ubsan:
|
|
|
|
Undefined Behavior Sanitizer (UBSan)
|
|
------------------------------------
|
|
|
|
Core Analysis Improvements
|
|
==========================
|
|
|
|
- ...
|
|
|
|
New Issues Found
|
|
================
|
|
|
|
- ...
|
|
|
|
Python Binding Changes
|
|
----------------------
|
|
|
|
The following methods have been added:
|
|
|
|
- ...
|
|
|
|
Significant Known Problems
|
|
==========================
|
|
|
|
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 via the `mailing
|
|
list <https://lists.llvm.org/mailman/listinfo/cfe-dev>`_.
|