=========================================== Clang |release| |ReleaseNotesTitle| =========================================== .. contents:: :local: :depth: 2 Written by the `LLVM Team `_ .. 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 `_. 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 `_. For the libc++ release notes, see `this page `_. 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 `_. Potentially Breaking Changes ============================ - The Objective-C ARC migrator (ARCMigrate) has been removed. C/C++ Language Potentially Breaking Changes ------------------------------------------- C++ Specific Potentially Breaking Changes ----------------------------------------- ABI Changes in This Version --------------------------- - Return larger CXX records in memory instead of using AVX registers. Code compiled with older clang will be incompatible with newer version of the clang unless -fclang-abi-compat=20 is provided. (#GH120670) AST Dumping Potentially Breaking Changes ---------------------------------------- Clang Frontend Potentially Breaking Changes ------------------------------------------- Clang Python Bindings Potentially Breaking Changes -------------------------------------------------- What's New in Clang |release|? ============================== C++ Language Changes -------------------- C++2c Feature Support ^^^^^^^^^^^^^^^^^^^^^ C++23 Feature Support ^^^^^^^^^^^^^^^^^^^^^ C++20 Feature Support ^^^^^^^^^^^^^^^^^^^^^ C++17 Feature Support ^^^^^^^^^^^^^^^^^^^^^ Resolutions to C++ Defect Reports ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - The flag `-frelaxed-template-template-args` and its negation have been removed, having been deprecated since the previous two releases. The improvements to template template parameter matching implemented in the previous release, as described in P3310 and P3579, made this flag unnecessary. C Language Changes ------------------ - Clang now allows an ``inline`` specifier on a typedef declaration of a function type in Microsoft compatibility mode. #GH124869 C2y Feature Support ^^^^^^^^^^^^^^^^^^^ 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 -------------------------- - The ``no_sanitize`` attribute now accepts both ``gnu`` and ``clang`` names. Improvements to Clang's diagnostics ----------------------------------- - Improve the diagnostics for deleted default constructor errors for C++ class initializer lists that don't explicitly list a class member and thus attempt to implicitly default construct that member. - The ``-Wunique-object-duplication`` warning has been added to warn about objects which are supposed to only exist once per program, but may get duplicated when built into a shared library. Improvements to Clang's time-trace ---------------------------------- Improvements to Coverage Mapping -------------------------------- Bug Fixes in This Version ------------------------- Bug Fixes to Compiler Builtins ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - The behvaiour of ``__add_pointer`` and ``__remove_pointer`` for Objective-C++'s ``id`` and interfaces has been fixed. Bug Fixes to Attribute Support ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - Fixed crash when a parameter to the ``clang::annotate`` attribute evaluates to ``void``. See #GH119125 Bug Fixes to C++ Support ^^^^^^^^^^^^^^^^^^^^^^^^ - Clang is now better at keeping track of friend function template instance contexts. (#GH55509) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ Miscellaneous Bug Fixes ^^^^^^^^^^^^^^^^^^^^^^^ - HTML tags in comments that span multiple lines are now parsed correctly by Clang's comment parser. (#GH120843) Miscellaneous Clang Crashes Fixed ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ OpenACC Specific Changes ------------------------ Target Specific Changes ----------------------- AMDGPU Support ^^^^^^^^^^^^^^ NVPTX Support ^^^^^^^^^^^^^^ Hexagon Support ^^^^^^^^^^^^^^^ - The default compilation target has been changed from V60 to V68. X86 Support ^^^^^^^^^^^ - Disable ``-m[no-]avx10.1`` and switch ``-m[no-]avx10.2`` to alias of 512 bit options. - Change ``-mno-avx10.1-512`` to alias of ``-mno-avx10.1-256`` to disable both 256 and 512 bit instructions. Arm and AArch64 Support ^^^^^^^^^^^^^^^^^^^^^^^ Android Support ^^^^^^^^^^^^^^^ Windows Support ^^^^^^^^^^^^^^^ LoongArch Support ^^^^^^^^^^^^^^^^^ RISC-V Support ^^^^^^^^^^^^^^ CUDA/HIP Language Changes ^^^^^^^^^^^^^^^^^^^^^^^^^ CUDA Support ^^^^^^^^^^^^ AIX Support ^^^^^^^^^^^ NetBSD Support ^^^^^^^^^^^^^^ WebAssembly Support ^^^^^^^^^^^^^^^^^^^ AVR Support ^^^^^^^^^^^ DWARF Support in Clang ---------------------- Floating Point Support in Clang ------------------------------- Fixed Point Support in Clang ---------------------------- AST Matchers ------------ clang-format ------------ libclang -------- Code Completion --------------- Static Analyzer --------------- New features ^^^^^^^^^^^^ Crash and bug fixes ^^^^^^^^^^^^^^^^^^^ Improvements ^^^^^^^^^^^^ Moved checkers ^^^^^^^^^^^^^^ .. _release-notes-sanitizers: Sanitizers ---------- Python Binding Changes ---------------------- OpenMP Support -------------- Improvements ^^^^^^^^^^^^ Additional Information ====================== A wide variety of additional information is available on the `Clang web page `_. 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) `_.