Clang

lastmod 2026-02-28created 2015-02-2831 edits

Clang is a compiler front end for the C, C++, Objective-C, and Objective-C++ programming languages. It uses LLVM as its back end and has been part of the release since LLVM 2.6.

Its goal is to replace the GNU Compiler Collection (GCC). Development is fully open source and is supported by large software companies such as Google and Apple. The source is available under the University of Illinois/NCSA Open Source License.

The Clang project includes the Clang front end and the Clang static analyzer.

Categories

• ClangFormat
• LLVM
• clang-format-node

Troubleshooting

Undefined symbols for architecture x86_64

• Stackoverflow: Undefined symbols for architecture x86_64 - Mavericks
• "undefined symbols for architecture x86_64" on Mavericks OSX

Add -stdlib=libstdc++ or -lstdc++ to the compiler flags.

deprecated-declarations error

On macOS, using a deprecated API may be treated as an error. This is because an option that turns warnings into errors has been applied:

-Werror=deprecated-declarations

To cancel this option, add the flag below.

-Wno-error=deprecated-declarations

See also

• gcc
• Zig
• LLVM
• clang:AST
• clang:ThreadSafetyAnalysis
• clang-format
  • LibFormat
• clang:config.h
• clang-tags
• clang-python (libclang python bindings)
• clang-tidy - Finding defects
• sanitizers
• clangd

vim integration

• vim-clang-tags
• vim-clang-format

Favorite site

• clang web site
• Wikipedia (en) description of Clang
• Build Clang On Windows project site
• Clang Compiler User’s Manual

How to install

• How to install clang++?
• Installing LLVM (@ubuntu)

Getting Started

• [Recommended] Getting Started: Building and Running Clang
• CLANG TUTORIAL PART I: INTRODUCTION ¹
• CLANG TUTORIAL PART II: LIBTOOLING EXAMPLE ²
• CLANG TUTORIAL PART III: PLUGIN EXAMPLE ³
• How To Cross-Compile Clang/LLVM using Clang/LLVM

Parser

• Parsing C++ in Python with Clang

With GCC

• Stackoverflow: Can Clang compile code with GCC compiled .a libs?
• Stackoverflow: Are llvm-gcc and clang binary compatible with gcc? - particularly mingw gcc on Windows

References