2021-05-04 00:32:36 +08:00
|
|
|
========================================
|
2021-01-27 11:37:08 +08:00
|
|
|
Clang 13.0.0 (In-Progress) Release Notes
|
2020-02-14 05:46:33 +08:00
|
|
|
========================================
|
|
|
|
|
|
|
|
|
|
.. contents::
|
|
|
|
|
:local:
|
|
|
|
|
:depth: 2
|
|
|
|
|
|
|
|
|
|
Written by the `LLVM Team <https://llvm.org/>`_
|
|
|
|
|
|
|
|
|
|
.. warning::
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
These are in-progress notes for the upcoming Clang 13 release.
|
2020-02-14 05:46:33 +08:00
|
|
|
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
|
2021-01-27 11:37:08 +08:00
|
|
|
frontend, part of the LLVM Compiler Infrastructure, release 13.0.0. Here we
|
2020-02-14 05:46:33 +08:00
|
|
|
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/>`_.
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
What's New in Clang 13.0.0?
|
2020-02-14 05:46:33 +08:00
|
|
|
===========================
|
|
|
|
|
|
|
|
|
|
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
|
|
|
|
|
------------------
|
|
|
|
|
|
2021-04-16 07:49:19 +08:00
|
|
|
- Guaranteed tail calls are now supported with statement attributes
|
|
|
|
|
``[[clang::musttail]]`` in C++ and ``__attribute__((musttail))`` in C. The
|
|
|
|
|
attribute is applied to a return statement (not a function declaration),
|
|
|
|
|
and an error is emitted if a tail call cannot be guaranteed, for example if
|
|
|
|
|
the function signatures of caller and callee are not compatible. Guaranteed
|
|
|
|
|
tail calls enable a class of algorithms that would otherwise use an
|
|
|
|
|
arbitrary amount of stack space.
|
2020-02-14 05:46:33 +08:00
|
|
|
|
|
|
|
|
Improvements to Clang's diagnostics
|
|
|
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
|
|
2020-07-15 17:40:53 +08:00
|
|
|
- ...
|
2020-06-05 00:45:04 +08:00
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
Non-comprehensive list of changes in this release
|
|
|
|
|
-------------------------------------------------
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
- ...
|
2020-05-26 02:44:35 +08:00
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
New Compiler Flags
|
|
|
|
|
------------------
|
|
|
|
|
|
2020-12-09 16:26:27 +08:00
|
|
|
- ``-Wreserved-identifier`` emits warning when user code uses reserved
|
|
|
|
|
identifiers.
|
2020-07-11 21:07:27 +08:00
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
Deprecated Compiler Flags
|
|
|
|
|
-------------------------
|
|
|
|
|
|
|
|
|
|
- ...
|
|
|
|
|
|
|
|
|
|
Modified Compiler Flags
|
|
|
|
|
-----------------------
|
|
|
|
|
|
2021-02-24 04:48:15 +08:00
|
|
|
- -Wshadow now also checks for shadowed structured bindings
|
2021-03-20 06:42:18 +08:00
|
|
|
- ``-B <prefix>`` (when ``<prefix>`` is a directory) was overloaded to additionally
|
|
|
|
|
detect GCC installations under ``<prefix>`` (``lib{,32,64}/gcc{,-cross}/$triple``).
|
|
|
|
|
This behavior was incompatible with GCC, caused interop issues with
|
|
|
|
|
``--gcc-toolchain``, and was thus dropped. Specify ``--gcc-toolchain=<dir>``
|
|
|
|
|
instead. ``-B``'s other GCC-compatible semantics are preserved:
|
|
|
|
|
``$prefix/$triple-$file`` and ``$prefix$file`` are searched for executables,
|
|
|
|
|
libraries, includes, and data files used by the compiler.
|
2020-02-14 05:46:33 +08:00
|
|
|
|
2020-12-17 22:23:02 +08:00
|
|
|
Removed Compiler Flags
|
|
|
|
|
-------------------------
|
|
|
|
|
|
2021-02-02 21:10:26 +08:00
|
|
|
- The clang-cl ``/fallback`` flag, which made clang-cl invoke Microsoft Visual
|
|
|
|
|
C++ on files it couldn't compile itself, has been removed.
|
2020-12-17 22:23:02 +08:00
|
|
|
|
2021-02-24 17:01:51 +08:00
|
|
|
- ``-Wreturn-std-move-in-c++11``, which checked whether an entity is affected by
|
|
|
|
|
`CWG1579 <https://wg21.link/CWG1579>`_ to become implicitly movable, has been
|
|
|
|
|
removed.
|
|
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
New Pragmas in Clang
|
|
|
|
|
--------------------
|
|
|
|
|
|
|
|
|
|
- ...
|
|
|
|
|
|
|
|
|
|
Attribute Changes in Clang
|
|
|
|
|
--------------------------
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
- ...
|
2020-02-14 05:46:33 +08:00
|
|
|
|
|
|
|
|
Windows Support
|
|
|
|
|
---------------
|
|
|
|
|
|
|
|
|
|
C Language Changes in Clang
|
|
|
|
|
---------------------------
|
|
|
|
|
|
2020-03-03 01:33:14 +08:00
|
|
|
- ...
|
2020-02-14 05:46:33 +08:00
|
|
|
|
|
|
|
|
C++ Language Changes in Clang
|
|
|
|
|
-----------------------------
|
|
|
|
|
|
2021-04-14 19:18:23 +08:00
|
|
|
- The oldest supported GNU libstdc++ is now 4.8.3 (released 2014-05-22).
|
|
|
|
|
Clang workarounds for bugs in earlier versions have been removed.
|
|
|
|
|
|
2020-07-15 17:40:53 +08:00
|
|
|
- ...
|
2020-02-14 05:46:33 +08:00
|
|
|
|
2021-04-14 19:18:23 +08:00
|
|
|
C++20 Feature Support
|
|
|
|
|
^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
|
...
|
|
|
|
|
|
|
|
|
|
C++2b Feature Support
|
2020-02-14 05:46:33 +08:00
|
|
|
^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
|
...
|
|
|
|
|
|
|
|
|
|
Objective-C Language Changes in Clang
|
|
|
|
|
-------------------------------------
|
|
|
|
|
|
|
|
|
|
OpenCL C Language Changes in Clang
|
|
|
|
|
----------------------------------
|
|
|
|
|
|
|
|
|
|
...
|
|
|
|
|
|
|
|
|
|
ABI Changes in Clang
|
|
|
|
|
--------------------
|
|
|
|
|
|
|
|
|
|
OpenMP Support in Clang
|
|
|
|
|
-----------------------
|
|
|
|
|
|
|
|
|
|
- ...
|
|
|
|
|
|
|
|
|
|
CUDA Support in Clang
|
|
|
|
|
---------------------
|
|
|
|
|
|
|
|
|
|
- ...
|
|
|
|
|
|
2020-08-21 04:37:51 +08:00
|
|
|
X86 Support in Clang
|
|
|
|
|
--------------------
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
- ...
|
2020-10-30 12:58:05 +08:00
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
Internal API Changes
|
|
|
|
|
--------------------
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
These are major API changes that have happened since the 12.0.0 release of
|
2020-02-14 05:46:33 +08:00
|
|
|
Clang. If upgrading an external codebase that uses Clang as a library,
|
|
|
|
|
this section should help get you past the largest hurdles of upgrading.
|
|
|
|
|
|
2020-07-15 17:40:53 +08:00
|
|
|
- ...
|
Removed a RecursiveASTVisitor feature to visit operator kinds with different methods
Summary:
This feature was only used in two places, but contributed a non-trivial
amount to the complexity of RecursiveASTVisitor, and was buggy (see my
recent patches where I was fixing the bugs that I noticed). I don't
think the convenience benefit of this feature is worth the complexity.
Besides complexity, another issue with the current state of
RecursiveASTVisitor is the non-uniformity in how it handles different
AST nodes. All AST nodes follow a regular pattern, but operators are
special -- and this special behavior not documented. Correct usage of
RecursiveASTVisitor relies on shadowing member functions with specific
names and signatures. Near misses don't cause any compile-time errors,
incorrectly named or typed methods are just silently ignored. Therefore,
predictability of RecursiveASTVisitor API is quite important.
This change reduces the size of the `clang` binary by 38 KB (0.2%) in
release mode, and by 7 MB (0.3%) in debug mode. The `clang-tidy` binary
is reduced by 205 KB (0.3%) in release mode, and by 5 MB (0.4%) in debug
mode. I don't think these code size improvements are significant enough
to justify this change on its own (for me, the primary motivation is
reducing code complexity), but they I think are a nice side-effect.
Reviewers: rsmith, sammccall, ymandel, aaron.ballman
Reviewed By: rsmith, sammccall, ymandel, aaron.ballman
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D82921
2020-07-03 23:01:01 +08:00
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
Build System Changes
|
|
|
|
|
--------------------
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
These are major changes to the build system that have happened since the 12.0.0
|
2020-02-14 05:46:33 +08:00
|
|
|
release of Clang. Users of the build system should adjust accordingly.
|
|
|
|
|
|
2021-03-02 02:20:53 +08:00
|
|
|
- The option ``LIBCLANG_INCLUDE_CLANG_TOOLS_EXTRA`` no longer exists. There were
|
|
|
|
|
two releases with that flag forced off, and no uses were added that forced it
|
|
|
|
|
on. The recommended replacement is clangd.
|
|
|
|
|
|
2020-07-15 17:40:53 +08:00
|
|
|
- ...
|
2020-02-14 05:46:33 +08:00
|
|
|
|
|
|
|
|
AST Matchers
|
|
|
|
|
------------
|
|
|
|
|
|
2021-01-27 11:37:08 +08:00
|
|
|
- ...
|
2020-05-23 09:12:51 +08:00
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
clang-format
|
|
|
|
|
------------
|
|
|
|
|
|
2021-01-30 05:01:42 +08:00
|
|
|
- Option ``SpacesInLineCommentPrefix`` has been added to control the
|
|
|
|
|
number of spaces in a line comments prefix.
|
2020-12-27 05:04:30 +08:00
|
|
|
|
2021-02-02 21:41:55 +08:00
|
|
|
- Option ``SortIncludes`` has been updated from a ``bool`` to an
|
|
|
|
|
``enum`` with backwards compatibility. In addition to the previous
|
2021-03-04 18:13:46 +08:00
|
|
|
``true``/``false`` states (now ``CaseSensitive``/``Never``), a third
|
|
|
|
|
state has been added (``CaseInsensitive``) which causes an alphabetical sort
|
2021-02-02 21:41:55 +08:00
|
|
|
with case used as a tie-breaker.
|
|
|
|
|
|
|
|
|
|
.. code-block:: c++
|
|
|
|
|
|
|
|
|
|
// Never (previously false)
|
|
|
|
|
#include "B/A.h"
|
|
|
|
|
#include "A/B.h"
|
|
|
|
|
#include "a/b.h"
|
|
|
|
|
#include "A/b.h"
|
|
|
|
|
#include "B/a.h"
|
|
|
|
|
|
2021-03-04 18:13:46 +08:00
|
|
|
// CaseSensitive (previously true)
|
2021-02-02 21:41:55 +08:00
|
|
|
#include "A/B.h"
|
|
|
|
|
#include "A/b.h"
|
|
|
|
|
#include "B/A.h"
|
|
|
|
|
#include "B/a.h"
|
|
|
|
|
#include "a/b.h"
|
|
|
|
|
|
2021-03-04 18:13:46 +08:00
|
|
|
// CaseInsensitive
|
2021-02-02 21:41:55 +08:00
|
|
|
#include "A/B.h"
|
|
|
|
|
#include "A/b.h"
|
|
|
|
|
#include "a/b.h"
|
|
|
|
|
#include "B/A.h"
|
|
|
|
|
#include "B/a.h"
|
|
|
|
|
|
2021-01-29 16:29:00 +08:00
|
|
|
- ``BasedOnStyle: InheritParentConfig`` allows to use the ``.clang-format`` of
|
|
|
|
|
the parent directories to overwrite only parts of it.
|
|
|
|
|
|
[clang-format] [PR19056] Add support for access modifiers indentation
Adds support for coding styles that make a separate indentation level for access modifiers, such as Code::Blocks or QtCreator.
The new option, `IndentAccessModifiers`, if enabled, forces the content inside classes, structs and unions (“records”) to be indented twice while removing a level for access modifiers. The value of `AccessModifierOffset` is disregarded in this case, aiming towards an ease of use.
======
The PR (https://bugs.llvm.org/show_bug.cgi?id=19056) had an implementation attempt by @MyDeveloperDay already (https://reviews.llvm.org/D60225) but I've decided to start from scratch. They differ in functionality, chosen approaches, and even the option name. The code tries to re-use the existing functionality to achieve this behavior, limiting possibility of breaking something else.
Reviewed By: MyDeveloperDay, curdeius, HazardyKnusperkeks
Differential Revision: https://reviews.llvm.org/D94661
2021-02-26 16:05:35 +08:00
|
|
|
- Option ``IndentAccessModifiers`` has been added to be able to give access
|
|
|
|
|
modifiers their own indentation level inside records.
|
|
|
|
|
|
2021-03-02 04:15:04 +08:00
|
|
|
- Option ``ShortNamespaceLines`` has been added to give better control
|
|
|
|
|
over ``FixNamespaceComments`` when determining a namespace length.
|
|
|
|
|
|
2021-03-06 04:30:47 +08:00
|
|
|
- Support for Whitesmiths has been improved, with fixes for ``namespace`` blocks
|
|
|
|
|
and ``case`` blocks and labels.
|
|
|
|
|
|
2021-04-15 23:27:20 +08:00
|
|
|
- Option ``EmptyLineAfterAccessModifier`` has been added to remove, force or keep
|
|
|
|
|
new lines after access modifiers.
|
|
|
|
|
|
2021-04-16 16:02:02 +08:00
|
|
|
- Checks for newlines in option ``EmptyLineBeforeAccessModifier`` are now based
|
|
|
|
|
on the formatted new lines and not on the new lines in the file. (Fixes
|
|
|
|
|
https://llvm.org/PR41870.)
|
|
|
|
|
|
2021-04-29 14:57:33 +08:00
|
|
|
- Option ``SpacesInAngles`` has been improved, it now accepts ``Leave`` value
|
|
|
|
|
that allows to keep spaces where they are already present.
|
|
|
|
|
|
2021-05-03 23:59:32 +08:00
|
|
|
- Option ``AllowShortIfStatementsOnASingleLine`` has been improved, it now
|
|
|
|
|
accepts ``AllIfsAndElse`` value that allows to put "else if" and "else" short
|
|
|
|
|
statements on a single line. (Fixes https://llvm.org/PR50019.)
|
|
|
|
|
|
2021-05-05 08:41:40 +08:00
|
|
|
- ``git-clang-format`` no longer formats changes to symbolic links. (Fixes
|
|
|
|
|
https://llvm.org/PR46992.)
|
|
|
|
|
|
2020-02-14 05:46:33 +08:00
|
|
|
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
|
2020-03-23 05:18:40 +08:00
|
|
|
API documentation which are up-to-date with the Git version of
|
2020-02-14 05:46:33 +08:00
|
|
|
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>`_.
|