Clang 15 |ReleaseNotesTitle|

Written by the LLVM Team

Introduction

This document contains the release notes for the Clang C/C++/Objective-C frontend, part of the LLVM Compiler Infrastructure, release 15. 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

These changes are ones which we think may surprise users when upgrading to Clang 15 because of the opportunity they pose for disruption to existing code bases.

C/C++ Language Potentially Breaking Changes

C++ Specific Potentially Breaking Changes

ABI Changes in This Version

AST Dumping Potentially Breaking Changes

What’s New in Clang 15?

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.

C++ Language Changes

C++20 Feature Support

C++23 Feature Support

C++2c Feature Support

Resolutions to C++ Defect Reports

C Language Changes

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

Improvements to Clang’s diagnostics

Improvements to Clang’s time-trace

Bug Fixes in This Version

Bug Fixes to Compiler Builtins

Bug Fixes to Attribute Support

Bug Fixes to C++ Support

Bug Fixes to AST Handling

Miscellaneous Bug Fixes

Miscellaneous Clang Crashes Fixed

OpenACC Specific Changes

Target Specific Changes

AMDGPU Support

X86 Support

Arm and AArch64 Support

Android Support

Windows Support

LoongArch Support

RISC-V Support

CUDA/HIP Language Changes

CUDA Support

AIX Support

WebAssembly Support

AVR Support

DWARF Support in Clang

Floating Point Support in Clang

AST Matchers

clang-format

libclang

Static Analyzer

New features

Crash and bug fixes

Improvements

  • Support importing C++20 modules in clang-repl.

Moved checkers

Sanitizers

Python Binding Changes

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).