.. 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 `_ .. 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 `_. 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 `_. For more information about Clang or LLVM, including information about the latest release, please see the `Clang Web Site `_ or the `LLVM Web Site `_. 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 `_. 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` ``zircon`` module. All checks have been moved to the ``fuchsia`` module instead. The ``zircon`` module will be removed in the 24th release. - Removed :program:`clang-tidy`'s global options `IgnoreMacros` and `StrictMode`, which were documented as deprecated since :program:`clang-tidy-20`. Users should use the check-specific options of the same name instead. - Renamed a few :program:`clang-tidy` check options, as they were misspelled: - `NamePrefixSuffixSilenceDissimilarityTreshold` to `NamePrefixSuffixSilenceDissimilarityThreshold` in :doc:`bugprone-easily-swappable-parameters ` - `CharTypdefsToIgnore` to `CharTypedefsToIgnore` in :doc:`bugprone-signed-char-misuse ` - Modified the custom message format of :doc:`bugprone-unsafe-functions ` by assigning a special meaning to the character ``>`` at the start of the value of the option ``CustomFunctions``. If the option value starts with ``>``, then the replacement suggestion part of the message (which would be included by default) is omitted. (This does not change the warning locations.) - :program:`clang-tidy` now displays warnings from all non-system headers by default. Previously, users had to explicitly opt-in to header warnings using `-header-filter='.*'`. To disable warnings from non-system, set `-header-filter` to an empty string. Improvements to clangd ---------------------- Inlay hints ^^^^^^^^^^^ Diagnostics ^^^^^^^^^^^ Semantic Highlighting ^^^^^^^^^^^^^^^^^^^^^ Compile flags ^^^^^^^^^^^^^ Hover ^^^^^ Code completion ^^^^^^^^^^^^^^^ Code actions ^^^^^^^^^^^^ - New ``Override pure virtual methods`` code action. When invoked on a class definition, this action automatically generates C++ ``override`` declarations for all pure virtual methods inherited from its base classes that have not yet been implemented. The generated method stubs prompts the user for the actual implementation. The overrides are intelligently grouped under their original access specifiers (e.g., ``public``, ``protected``), creating new access specifier blocks if necessary. Signature help ^^^^^^^^^^^^^^ Cross-references ^^^^^^^^^^^^^^^^ Objective-C ^^^^^^^^^^^ Miscellaneous ^^^^^^^^^^^^^ Improvements to clang-doc ------------------------- Improvements to clang-query --------------------------- - Matcher queries interpreted by clang-query are now support trailing comma (,) in matcher arguments. Note that C++ still doesn't allow this in function arguments. So when porting a query to C++, remove all instances of trailing comma (otherwise C++ compiler will just complain about "expected expression"). Improvements to clang-tidy -------------------------- - The :program:`check_clang_tidy.py` tool now recognizes the ``-std`` argument when run over C files. If ``-std`` is not specified, it defaults to ``c99-or-later``. - :program:`clang-tidy` now displays warnings from all non-system headers by default. Previously, users had to explicitly opt-in to header warnings using `-header-filter='.*'`. To disable warnings from non-system, set `-header-filter` to an empty string. - :program:`clang-tidy` no longer attempts to analyze code from system headers by default, greatly improving performance. This behavior is disabled if the `SystemHeaders` option is enabled. - :program:`clang-tidy` now supports query based custom checks by `CustomChecks` configuration option. :doc:`Query Based Custom Check Document ` - The :program:`run-clang-tidy.py` and :program:`clang-tidy-diff.py` scripts now run checks in parallel by default using all available hardware threads. Both scripts display the number of threads being used in their output. - Improved :program:`run-clang-tidy.py` by adding a new option `enable-check-profile` to enable per-check timing profiles and print a report based on all analyzed files. - Improved documentation of the `-line-filter` command-line flag of :program:`clang-tidy` and :program:`run-clang-tidy.py`. - Improved :program:`clang-tidy` option `-quiet` by suppressing diagnostic count messages. - Improved :program:`clang-tidy` by not crashing when an empty `directory` field is used in a compilation database; the current working directory will be used instead, and an error message will be printed. - Removed :program:`clang-tidy`'s global options `IgnoreMacros` and `StrictMode`, which were documented as deprecated since :program:`clang-tidy-20`. Users should use the check-specific options of the same name instead. - Improved :program:`run-clang-tidy.py` and :program:`clang-tidy-diff.py` scripts by adding the `-hide-progress` option to suppress progress and informational messages. - Deprecated the :program:`clang-tidy` ``zircon`` module. All checks have been moved to the ``fuchsia`` module instead. The ``zircon`` module will be removed in the 24th release. New checks ^^^^^^^^^^ - New :doc:`bugprone-derived-method-shadowing-base-method ` check. Finds derived class methods that shadow a (non-virtual) base class method. - New :doc:`bugprone-invalid-enum-default-initialization ` check. Detects default initialization (to 0) of variables with ``enum`` type where the enum has no enumerator with value of 0. - New :doc:`cppcoreguidelines-pro-bounds-avoid-unchecked-container-access ` check. Finds calls to ``operator[]`` in STL containers and suggests replacing them with safe alternatives. - New :doc:`google-runtime-float ` check. Finds uses of ``long double`` and suggests against their use due to lack of portability. - New :doc:`llvm-mlir-op-builder ` check. Checks for uses of MLIR's old/to be deprecated ``OpBuilder::create`` form and suggests using ``T::create`` instead. - New :doc:`llvm-use-ranges ` check. Finds calls to STL library iterator algorithms that could be replaced with LLVM range-based algorithms from ``llvm/ADT/STLExtras.h``. - New :doc:`misc-override-with-different-visibility ` check. Finds virtual function overrides with different visibility than the function in the base class. - New :doc:`readability-redundant-parentheses ` check. Detect redundant parentheses. - New :doc:`readability-redundant-typename ` check. Finds redundant uses of the ``typename`` keyword. New check aliases ^^^^^^^^^^^^^^^^^ - Renamed :doc:`cert-dcl50-cpp ` to :doc:`modernize-avoid-variadic-functions ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-dcl58-cpp ` to :doc:`bugprone-std-namespace-modification ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-env33-c ` to :doc:`bugprone-command-processor ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-err34-c ` to :doc:`bugprone-unchecked-string-to-number-conversion ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-err52-cpp ` to :doc:`modernize-avoid-setjmp-longjmp ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-err58-cpp ` to :doc:`bugprone-throwing-static-initialization ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-err60-cpp ` to :doc:`bugprone-exception-copy-constructor-throws ` - Renamed :doc:`cert-flp30-c ` to :doc:`bugprone-float-loop-counter ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-mem57-cpp ` to :doc:`bugprone-default-operator-new-on-overaligned-type ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-msc30-c ` to :doc:`misc-predictable-rand ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-msc32-c ` to :doc:`bugprone-random-generator-seed ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-msc50-cpp ` to :doc:`misc-predictable-rand ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-msc51-cpp ` to :doc:`bugprone-random-generator-seed ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-oop57-cpp ` to :doc:`bugprone-raw-memory-call-on-non-trivial-type ` keeping initial check as an alias to the new one. - Renamed :doc:`cert-oop58-cpp ` to :doc:`bugprone-copy-constructor-mutates-argument ` keeping initial check as an alias to the new one. Changes in existing checks ^^^^^^^^^^^^^^^^^^^^^^^^^^ - Improved :doc:`bugprone-easily-swappable-parameters ` check by correcting a spelling mistake on its option ``NamePrefixSuffixSilenceDissimilarityTreshold``. - Improved :doc:`bugprone-exception-escape ` check's handling of lambdas: exceptions from captures are now diagnosed, exceptions in the bodies of lambdas that aren't actually invoked are not. Additionally, fixed an issue where the check wouldn't diagnose throws in arguments to functions or constructors. Added fine-grained configuration via options `CheckDestructors`, `CheckMoveMemberFunctions`, `CheckMain`, `CheckedSwapFunctions`, and `CheckNothrowFunctions`. - Improved :doc:`bugprone-infinite-loop ` check by adding detection for variables introduced by structured bindings. - Improved :doc:`bugprone-invalid-enum-default-initialization ` with new `IgnoredEnums` option to ignore specified enums during analysis. - Improved :doc:`bugprone-narrowing-conversions ` check by fixing false positive from analysis of a conditional expression in C. - Improved :doc:`bugprone-not-null-terminated-result ` check by fixing bogus fix-its for ``strncmp`` and ``wcsncmp`` on Windows and a crash caused by certain value-dependent expressions. - Improved :doc:`bugprone-reserved-identifier ` check by ignoring declarations and macros in system headers. - Improved :doc:`bugprone-signed-char-misuse ` check by fixing false positives on C23 enums with the fixed underlying type of signed char. - Improved :doc:`bugprone-sizeof-expression ` check by fixing a crash on ``sizeof`` of an array of dependent type. - Improved :doc:`bugprone-suspicious-include ` check by adding `IgnoredRegex` option. - Improved :doc:`bugprone-tagged-union-member-count ` by fixing a false positive when enums or unions from system header files or the ``std`` namespace are treated as the tag or the data part of a user-defined tagged union respectively. - Improved :doc:`bugprone-throw-keyword-missing ` check by only considering the canonical types of base classes as written and adding a note on the base class that triggered the warning. - Improved :doc:`bugprone-unchecked-optional-access ` check by supporting ``NullableValue::makeValue`` and ``NullableValue::makeValueInplace`` to prevent false-positives for ``BloombergLP::bdlb::NullableValue`` type, and by adding the `IgnoreValueCalls` option to suppress diagnostics for ``optional::value()`` and the `IgnoreSmartPointerDereference` option to ignore optionals reached via smart-pointer-like dereference, while still diagnosing UB-prone dereferences via ``operator*`` and ``operator->``. - Improved :doc:`bugprone-unhandled-self-assignment ` check by adding an additional matcher that generalizes the copy-and-swap idiom pattern detection. - Improved :doc:`bugprone-unsafe-functions ` check by hiding the default suffix when the reason starts with the character `>` in the `CustomFunctions` option. - Improved :doc:`cppcoreguidelines-avoid-non-const-global-variables ` check by adding a new option `AllowThreadLocal` that suppresses warnings on non-const global variables with thread-local storage duration. - Improved :doc:`cppcoreguidelines-init-variables ` check by fixing the insertion location for function pointers with multiple parameters. - Improved :doc:`cppcoreguidelines-macro-usage ` check by excluding macro bodies that starts with ``__attribute__((..))`` keyword. Such a macro body is unlikely a proper expression and so suggesting users an impossible rewrite into a template function should be avoided. - Improved :doc:`cppcoreguidelines-prefer-member-initializer ` check to avoid false positives on inherited members in class templates. - Improved :doc:`cppcoreguidelines-pro-bounds-pointer-arithmetic ` check adding an option to allow pointer arithmetic via prefix/postfix increment or decrement operators. - Improved :doc:`google-readability-casting ` check by adding fix-it notes for downcasts and casts to void pointer. - Improved :doc:`google-readability-todo ` check to accept the new TODO format from the Google Style Guide. - Improved :doc:`llvm-prefer-isa-or-dyn-cast-in-conditionals ` check: - Fix-it handles callees with nested-name-specifier correctly. - ``if`` statements with init-statement (``if (auto X = ...; ...)``) are handled correctly. - ``for`` loops are supported. - Improved :doc:`misc-const-correctness ` check to avoid false positives when pointers is transferred to non-const references and avoid false positives of function pointer and fix false positives on return of non-const pointer and fix false positives on pointer-to-member operator. - Improved :doc:`misc-coroutine-hostile-raii ` check by adding the option `AllowedCallees`, that allows exempting safely awaitable callees from the check. - Improved :doc:`misc-header-include-cycle ` check performance. - Improved :doc:`modernize-avoid-c-arrays ` to not diagnose array types which are part of an implicit instantiation of a template. - Improved :doc:`modernize-use-constraints ` check by fixing a crash on uses of non-standard ``enable_if`` with a signature different from ``std::enable_if`` (such as ``boost::enable_if``). - Improved :doc:`modernize-use-default-member-init ` check to enhance the robustness of the member initializer detection. - Improved :doc:`modernize-use-designated-initializers ` check to suggest using designated initializers for aliased aggregate types. - Improved :doc:`modernize-use-integer-sign-comparison ` by providing correct fix-its when the right-hand side of a comparison contains a non-C-style cast. - Improved :doc:`modernize-use-nullptr ` check by fixing a crash on Windows when the check was enabled with a 32-bit :program:`clang-tidy` binary. - Improved :doc:`modernize-use-scoped-lock ` check by fixing a crash on malformed code (common when using :program:`clang-tidy` through :program:`clangd`). - Improved :doc:`modernize-use-std-format ` check to correctly match when the format string is converted to a different type by an implicit constructor call. - Improved :doc:`modernize-use-std-print ` check to correctly match when the format string is converted to a different type by an implicit constructor call, and fixed a crash when handling format strings containing non-ASCII characters. - Improved :doc:`performance-unnecessary-copy-initialization ` by printing the type of the diagnosed variable. - Improved :doc:`performance-unnecessary-value-param ` by printing the type of the diagnosed variable and correctly generating fix-it hints for parameter-pack arguments. - Improved :doc:`portability-template-virtual-member-function ` check to avoid false positives on pure virtual member functions. - Improved :doc:`readability-container-contains ` to support string comparisons to ``npos``. Internal changes may cause new rare false positives in non-standard containers. - Improved :doc:`readability-container-data-pointer ` check by correctly adding parentheses when the container expression is a dereference. - Improved :doc:`readability-container-size-empty ` check by correctly generating fix-it hints when size method is called from implicit ``this``, ignoring default constructors with user provided arguments and adding detection in container's method except ``empty``. - Improved :doc:`readability-duplicate-include ` check by adding the ``IgnoredFilesList`` option (semicolon-separated list of regexes or filenames) to allow intentional duplicates. - Improved :doc:`readability-identifier-naming ` check by ignoring declarations and macros in system headers. The documentation is also improved to differentiate the general options from the specific ones. Options for fine-grained control over ``constexpr`` variables were added. - Improved :doc:`readability-implicit-bool-conversion ` check by correctly adding parentheses when the inner expression are implicitly converted multiple times. - Improved :doc:`readability-qualified-auto ` check by adding the option `IgnoreAliasing`, that allows not looking at underlying types of type aliases. - Improved :doc:`readability-uppercase-literal-suffix ` check to recognize literal suffixes added in C++23 and C23. - Improved :doc:`readability-use-concise-preprocessor-directives ` check to generate correct fix-its for forms without a space after the directive. Removed checks ^^^^^^^^^^^^^^ Miscellaneous ^^^^^^^^^^^^^ Improvements to include-fixer ----------------------------- The improvements are... Improvements to clang-include-fixer ----------------------------------- The improvements are... Improvements to modularize -------------------------- The improvements are... Improvements to pp-trace ------------------------ Clang-tidy Visual Studio plugin -------------------------------