arch-wiki-md-repo/wiki/_content/english/Clang.md

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[Clang](http://clang.llvm.org/) is a C/C++/Objective C compiler based on LLVM. It is distributed under the BSD Licence.

## Contents

*   [1 Installation](#Installation)
*   [2 Build packages with Clang](#Build_packages_with_Clang)
*   [3 Using the Static Analyzer](#Using_the_Static_Analyzer)
*   [4 References](#References)

## Installation

Install [clang](https://www.archlinux.org/packages/?name=clang) from the [Official repositories](/index.php/Official_repositories "Official repositories").

## Build packages with Clang

Add `export CC=clang` and (for C++) `export CXX=clang++` to your `/etc/makepkg.conf`. If you are building with `debug` also remove `-fvar-tracking-assignments` from `DEBUG_CFLAGS` and `DEBUG_CXXFLAGS` as clang does not support it.

NB: For packages that specify GCC-specific build options, there may be build errors that require either editing the source package, the pkgbuild or commenting out the clang lines in makepkg.conf.

## Using the Static Analyzer

To analyze a project, simply place the word `scan-build` in front of your build command. For example:

```
$ scan-build make

```

**Tip:** If your project is already compiled, `scan-build` won't rebuild and won't analyse it. To force recompilation and analysis, use `-B` switch: `$ scan-build make -B` 

It is also possible to analyze specific files:

```
$ scan-build gcc -c t1.c t2.c

```

## References

*   [scan-build: running the analyzer from the command line](http://clang-analyzer.llvm.org/scan-build.html)