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.. If you want to modify sections/contents permanently, you should modify both
ReleaseNotes.rst and ReleaseNotesTemplate.txt.
====================================================
Extra Clang Tools |release| |ReleaseNotesTitle|
====================================================
.. contents::
:local:
:depth: 3
Written by the `LLVM Team <https://llvm.org/>`_
.. only:: PreRelease
.. warning::
These are in-progress notes for the upcoming Extra Clang Tools |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 Extra Clang Tools, part of the
Clang release |release|. Here we describe the status of the Extra Clang Tools in
some detail, including major improvements from the previous release and new
feature work. 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 Extra Clang Tools |release|?
==========================================
Some of the major new features and improvements to Extra Clang Tools are listed
here. Generic improvements to Extra Clang Tools as a whole or to its underlying
infrastructure are described first, followed by tool-specific sections.
Major New Features
------------------
Potentially Breaking Changes
----------------------------
- Deprecated the :program:`clang-tidy` check :doc:`performance-faster-string-find
<clang-tidy/checks/performance/faster-string-find>`. It has been renamed to
:doc:`performance-prefer-single-char-overloads
<clang-tidy/checks/performance/prefer-single-char-overloads>`.
The original check will be removed in the 25th release.
Improvements to clangd
----------------------
Inlay hints
^^^^^^^^^^^
Diagnostics
^^^^^^^^^^^
Semantic Highlighting
^^^^^^^^^^^^^^^^^^^^^
Compile flags
^^^^^^^^^^^^^
Hover
^^^^^
Code completion
^^^^^^^^^^^^^^^
- Now also provides include files without extension, if they are in a directory
only called ``include``.
Code actions
^^^^^^^^^^^^
Signature help
^^^^^^^^^^^^^^
Cross-references
^^^^^^^^^^^^^^^^
Objective-C
^^^^^^^^^^^
Miscellaneous
^^^^^^^^^^^^^
Improvements to clang-doc
-------------------------
Improvements to clang-query
---------------------------
Improvements to clang-tidy
--------------------------
- Improved :program:`check_clang_tidy.py` script by adding the `-check-header`
argument to simplify testing of header files. This argument automatically
manages the creation of temporary header files and ensures that diagnostics
and fixes are verified for the specified headers.
- Improved :program:`clang-tidy` ``-store-check-profile`` by generating valid
JSON when the source file path contains characters that require JSON escaping.
New checks
^^^^^^^^^^
- New :doc:`bugprone-unsafe-to-allow-exceptions
<clang-tidy/checks/bugprone/unsafe-to-allow-exceptions>` check.
Finds functions where throwing exceptions is unsafe but the function is still
marked as potentially throwing.
- New :doc:`llvm-type-switch-case-types
<clang-tidy/checks/llvm/type-switch-case-types>` check.
Finds ``llvm::TypeSwitch::Case`` calls with redundant explicit template
arguments that can be inferred from the lambda parameter type.
- New :doc:`llvm-use-vector-utils
<clang-tidy/checks/llvm/use-vector-utils>` check.
Finds calls to ``llvm::to_vector(llvm::map_range(...))`` and
``llvm::to_vector(llvm::make_filter_range(...))`` that can be replaced with
``llvm::map_to_vector`` and ``llvm::filter_to_vector``.
- New :doc:`modernize-use-std-bit
<clang-tidy/checks/modernize/use-std-bit>` check.
Finds common idioms which can be replaced by standard functions from the
``<bit>`` C++20 header.
- New :doc:`modernize-use-string-view
<clang-tidy/checks/modernize/use-string-view>` check.
Looks for functions returning ``std::[w|u8|u16|u32]string`` and suggests to
change it to ``std::[...]string_view`` for performance reasons if possible.
- New :doc:`modernize-use-structured-binding
<clang-tidy/checks/modernize/use-structured-binding>` check.
Finds places where structured bindings could be used to decompose pairs and
suggests replacing them.
- New :doc:`performance-string-view-conversions
<clang-tidy/checks/performance/string-view-conversions>` check.
Finds and removes redundant conversions from ``std::[w|u8|u16|u32]string_view`` to
``std::[...]string`` in call expressions expecting ``std::[...]string_view``.
- New :doc:`performance-use-std-move
<clang-tidy/checks/performance/use-std-move>` check.
Suggests insertion of ``std::move(...)`` to turn copy assignment operator
calls into move assignment ones, when deemed valid and profitable.
- New :doc:`readability-redundant-qualified-alias
<clang-tidy/checks/readability/redundant-qualified-alias>` check.
Finds redundant identity type aliases that re-expose a qualified name and can
be replaced with a ``using`` declaration.
- New :doc:`readability-trailing-comma
<clang-tidy/checks/readability/trailing-comma>` check.
Checks for presence or absence of trailing commas in enum definitions and
initializer lists.
New check aliases
^^^^^^^^^^^^^^^^^
- Renamed :doc:`hicpp-exception-baseclass
<clang-tidy/checks/hicpp/exception-baseclass>`
to :doc:`bugprone-std-exception-baseclass
<clang-tidy/checks/bugprone/std-exception-baseclass>`.
The `hicpp-exception-baseclass` name is kept as an alias.
- Renamed :doc:`hicpp-ignored-remove-result
<clang-tidy/checks/hicpp/ignored-remove-result>`
to :doc:`bugprone-unused-return-value
<clang-tidy/checks/bugprone/unused-return-value>`.
The `hicpp-ignored-remove-result` name is kept as an alias.
- Renamed :doc:`hicpp-no-assembler <clang-tidy/checks/hicpp/no-assembler>`
to :doc:`portability-no-assembler
<clang-tidy/checks/portability/no-assembler>`. The `hicpp-no-assembler`
name is kept as an alias.
- Renamed :doc:`performance-faster-string-find
<clang-tidy/checks/performance/faster-string-find>` to
:doc:`performance-prefer-single-char-overloads
<clang-tidy/checks/performance/prefer-single-char-overloads>`.
The `performance-faster-string-find` name is kept as an alias.
Changes in existing checks
^^^^^^^^^^^^^^^^^^^^^^^^^^
- Improved :doc:`bugprone-argument-comment
<clang-tidy/checks/bugprone/argument-comment>` to also check for C++11
inherited constructors.
- Improved :doc:`bugprone-bad-signal-to-kill-thread
<clang-tidy/checks/bugprone/bad-signal-to-kill-thread>` check by fixing false
negatives when the ``SIGTERM`` macro is obtained from a precompiled header.
- Improved :doc:`bugprone-casting-through-void
<clang-tidy/checks/bugprone/casting-through-void>` check by running only on
C++ files because suggested ``reinterpret_cast`` is not available in pure C.
- Improved :doc:`bugprone-derived-method-shadowing-base-method
<clang-tidy/checks/bugprone/derived-method-shadowing-base-method>` check by
correctly ignoring function templates.
- Improved :doc:`bugprone-exception-escape
<clang-tidy/checks/bugprone/exception-escape>` check by adding
`TreatFunctionsWithoutSpecificationAsThrowing` option to support reporting
for unannotated functions, enabling reporting when no explicit ``throw``
is seen and allowing separate tuning for known and unknown implementations.
- Improved :doc:`bugprone-fold-init-type
<clang-tidy/checks/bugprone/fold-init-type>` check by detecting precision
loss in overloads with transparent standard functors (e.g. ``std::plus<>``)
for ``std::accumulate``, ``std::reduce``, and ``std::inner_product``.
- Improved :doc:`bugprone-inc-dec-in-conditions
<clang-tidy/checks/bugprone/inc-dec-in-conditions>` check by fixing a false
positive when increment/decrement operators appear inside lambda bodies that
are part of a condition expression.
- Improved :doc:`bugprone-macro-parentheses
<clang-tidy/checks/bugprone/macro-parentheses>` check by printing the macro
definition in the warning message if the macro is defined on command line.
- Improved :doc:`bugprone-pointer-arithmetic-on-polymorphic-object
<clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object>` check
by fixing a false positive when ``operator[]`` is used in a dependent context.
- Improved :doc:`bugprone-std-namespace-modification
<clang-tidy/checks/bugprone/std-namespace-modification>` check by fixing
false positives when extending the standard library with a specialization of
user-defined type and by removing detection of the compiler generated ``std``
namespace extensions.
- Improved :doc:`bugprone-string-constructor
<clang-tidy/checks/bugprone/string-constructor>` check to detect suspicious
string constructor calls when the string class constructor has a default
allocator argument.
- Improved :doc:`bugprone-unchecked-optional-access
<clang-tidy/checks/bugprone/unchecked-optional-access>` to recognize common
GoogleTest macros such as ``ASSERT_TRUE`` and ``ASSERT_FALSE``, reducing the
number of false positives in test code.
- Improved :doc:`bugprone-unsafe-functions
<clang-tidy/checks/bugprone/unsafe-functions>` check by adding the function
``std::get_temporary_buffer`` to the default list of unsafe functions. (This
function is unsafe, useless, deprecated in C++17 and removed in C++20).
- Improved :doc:`bugprone-use-after-move
<clang-tidy/checks/bugprone/use-after-move>` check:
- Include the name of the invalidating function in the warning message when a
custom invalidation function is used (via the `InvalidationFunctions`
option).
- Add support for annotation of user-defined types as having the same
moved-from semantics as standard smart pointers.
- Do not report explicit call to destructor after move as an invalid use.
- Improved :doc:`cppcoreguidelines-avoid-capturing-lambda-coroutines
<clang-tidy/checks/cppcoreguidelines/avoid-capturing-lambda-coroutines>`
check by adding the `AllowExplicitObjectParameters` option. When enabled,
lambda coroutines using C++23 deducing ``this`` (explicit object parameter)
are not flagged.
- Improved :doc:`cppcoreguidelines-init-variables
<clang-tidy/checks/cppcoreguidelines/init-variables>` check by ensuring that
member pointers are correctly flagged as uninitialized.
- Improved :doc:`cppcoreguidelines-missing-std-forward
<clang-tidy/checks/cppcoreguidelines/missing-std-forward>` check by fixing
a false positive for constrained template parameters.
- Improved :doc:`cppcoreguidelines-pro-type-member-init
<clang-tidy/checks/cppcoreguidelines/pro-type-member-init>` check by fixing
a false positive when a base class has a forward declaration before its
definition.
- Improved :doc:`cppcoreguidelines-pro-type-vararg
<clang-tidy/checks/cppcoreguidelines/pro-type-vararg>` check by no longer
warning on builtins with custom type checking (e.g., type-generic builtins
like ``__builtin_clzg``) that use variadic declarations as an implementation
detail.
- Improved :doc:`cppcoreguidelines-rvalue-reference-param-not-moved
<clang-tidy/checks/cppcoreguidelines/rvalue-reference-param-not-moved>` check
by fixing a false positive on implicitly generated functions such as
inherited constructors.
- Improved :doc:`llvm-use-ranges
<clang-tidy/checks/llvm/use-ranges>` check by adding support for the following
algorithms: ``std::accumulate``, ``std::replace_copy``, and
``std::replace_copy_if``.
- Improved :doc:`misc-const-correctness
<clang-tidy/checks/misc/const-correctness>` check:
- Added support for analyzing function parameters with the `AnalyzeParameters`
option.
- Fixed false positive where an array of pointers to ``const`` was
incorrectly diagnosed as allowing the pointee to be made ``const``.
- Fixed false positive where a pointer used with placement new was
incorrectly diagnosed as allowing the pointee to be made ``const``.
- Improved :doc:`misc-multiple-inheritance
<clang-tidy/checks/misc/multiple-inheritance>` by avoiding false positives when
virtual inheritance causes concrete bases to be counted more than once.
- Improved :doc:`misc-throw-by-value-catch-by-reference
<clang-tidy/checks/misc/throw-by-value-catch-by-reference>` check:
- Fixed the `WarnOnLargeObject` option to use the correct name when
storing the configuration.
- Fixed the `CheckThrowTemporaries` option to correctly reflect its
configured value in exported settings.
- Improved :doc:`misc-unused-using-decls
<clang-tidy/checks/misc/unused-using-decls>` to not diagnose ``using``
declarations as unused if they're exported from a module.
- Improved :doc:`modernize-pass-by-value
<clang-tidy/checks/modernize/pass-by-value>` check by adding `IgnoreMacros`
option to suppress warnings in macros.
- Improved :doc:`modernize-redundant-void-arg
<clang-tidy/checks/modernize/redundant-void-arg>` check to work in C23.
- Improved :doc:`modernize-use-equals-delete
<clang-tidy/checks/modernize/use-equals-delete>` check by only warning on
private deleted functions, if they do not have a public overload or are a
special member function.
- Improved :doc:`modernize-use-std-format
<clang-tidy/checks/modernize/use-std-format>` check:
- Fixed a crash when an argument is part of a macro expansion.
- Added missing ``#include`` insertion when the format function call
appears as an argument to a macro.
- Improved :doc:`modernize-use-std-print
<clang-tidy/checks/modernize/use-std-print>` check by adding missing
``#include`` insertion when the format function call appears as an
argument to a macro.
- Improved :doc:`modernize-use-trailing-return-type
<clang-tidy/checks/modernize/use-trailing-return-type>` check by fixing
spurious ``missing '(' after '__has_feature'`` errors caused by builtin
macros appearing in the return type of a function.
- Improved :doc:`modernize-use-using
<clang-tidy/checks/modernize/use-using>` check by avoiding the generation
of invalid code for function types with redundant parentheses.
- Improved :doc:`performance-enum-size
<clang-tidy/checks/performance/enum-size>` check:
- Exclude ``enum`` in ``extern "C"`` blocks.
- Improved the ignore list to correctly handle ``typedef`` and ``enum``.
- Improved :doc:`performance-inefficient-string-concatenation
<clang-tidy/checks/performance/inefficient-string-concatenation>` check by
adding support for detecting inefficient string concatenation in ``do-while``
loops.
- Improved :doc:`performance-inefficient-vector-operation
<clang-tidy/checks/performance/inefficient-vector-operation>` check by
correctly handling vector-like classes when ``push_back``/``emplace_back`` are
inherited.
- Improved :doc:`performance-move-const-arg
<clang-tidy/checks/performance/move-const-arg>` check by avoiding false
positives on trivially copyable types with a non-public copy constructor.
- Improved :doc:`performance-prefer-single-char-overloads
<clang-tidy/checks/performance/prefer-single-char-overloads>` check:
- Now analyzes calls to the ``starts_with``, ``ends_with``, ``contains``,
and ``operator+=`` string member functions.
- Fixes false negatives when using ``std::set`` from ``libstdc++``.
- Improved :doc:`readability-container-size-empty
<clang-tidy/checks/readability/container-size-empty>` check:
- Fix a crash when a member expression has a non-identifier name.
- Reduce verbosity by removing the note indicating source location of the
``empty`` function.
- Improved :doc:`readability-else-after-return
<clang-tidy/checks/readability/else-after-return>` check:
- Fixed missed diagnostics when ``if`` statements appear in unbraced
``switch`` case labels.
- Fixed a false positive involving ``if`` statements which contain
a ``return``, ``break``, etc., jumped over by a ``goto``.
- Fixed the check potentially breaking code by deleting one too many
characters following an ``else`` or a curly brace.
- Added support for handling attributed ``if`` then-branches such as
``[[likely]]`` and ``[[unlikely]]``.
- Diagnose and remove redundant ``else`` branches after calls to
``[[noreturn]]`` functions.
- Improved :doc:`readability-enum-initial-value
<clang-tidy/checks/readability/enum-initial-value>` check: the warning message
now uses separate note diagnostics for each uninitialized enumerator, making
it easier to see which specific enumerators need explicit initialization.
- Improved :doc:`readability-identifier-naming
<clang-tidy/checks/readability/identifier-naming>` check by fixing incorrect
naming style application to C++17 structured bindings.
- Improved :doc:`readability-implicit-bool-conversion
<clang-tidy/checks/readability/implicit-bool-conversion>` check:
- Fixed a false positive where `AllowPointerConditions` and
`AllowIntegerConditions` options did not suppress warnings when the
condition expression involved temporaries (e.g. passing a string literal to
a ``const std::string&`` parameter).
- Warn and provide fix-its when a macro defined in a system header (e.g.
``NULL``) is implicitly converted to ``bool``.
- Added `AllowLogicalOperatorConversion` option to suppress warnings on
implicit conversions of logical operator results (``&&``, ``||``, ``!``)
to ``bool`` in C.
- Improved :doc:`readability-non-const-parameter
<clang-tidy/checks/readability/non-const-parameter>` check by avoiding false
positives on parameters used in dependent expressions (e.g. inside generic
lambdas).
- Improved :doc:`readability-redundant-preprocessor
<clang-tidy/checks/readability/redundant-preprocessor>` check by fixing a
false positive for nested ``#if`` directives using different builtin
expressions such as ``__has_builtin`` and ``__has_cpp_attribute``.
- Improved :doc:`readability-simplify-boolean-expr
<clang-tidy/checks/readability/simplify-boolean-expr>` check to provide valid
fix suggestions for C23 and later by not using ``static_cast``.
- Improved :doc:`readability-simplify-subscript-expr
<clang-tidy/checks/readability/simplify-subscript-expr>` check by fixing
missing warnings when subscripting an object held inside a generic
container (e.g. subscripting a ``std::string`` held inside a
``std::vector<std::string>``).
- Improved :doc:`readability-suspicious-call-argument
<clang-tidy/checks/readability/suspicious-call-argument>` check by avoiding a
crash from invalid ``Abbreviations`` option.
Removed checks
^^^^^^^^^^^^^^
Miscellaneous
^^^^^^^^^^^^^
Improvements to include-fixer
-----------------------------
Improvements to clang-include-fixer
-----------------------------------
Improvements to modularize
--------------------------
Improvements to pp-trace
------------------------
Clang-tidy Visual Studio plugin
-------------------------------