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+# meta-clang (a C language family frontend and LLVM compiler backend)
+
+This layer provides [clang/llvm](http://clang.llvm.org/) as alternative to your system
+C/C++ compiler for OpenEmbedded based distributions along with gcc
+
+# Getting Started
+
+```shell
+git clone git://github.com/openembedded/openembedded-core.git
+cd openembeeded-core
+git clone git://github.com/openembedded/bitbake.git
+git clone git://github.com/kraj/meta-clang.git
+
+$ . ./oe-init-build-env
+```
+
+Edit conf/bblayers.conf to add meta-clang to layer mix e.g.
+
+```python
+BBLAYERS ?= " \
+  /home/kraj/openembedded-core/meta-clang \
+  /home/kraj/openembedded-core/meta \
+  "
+```
+
+# Default Compiler Switch
+
+Note that by default gcc will remain the system compiler, however if you wish
+clang to be the default compiler then set
+
+```python
+TOOLCHAIN ?= "clang"
+```
+
+in local.conf, this would now switch to using clang as default compiler systemwide
+you can select clang per package too by writing bbappends for them containing
+
+```python
+TOOLCHAIN = "clang"
+```
+
+# Default C++ Standard Library Switch
+
+Note that by default libstdc++ will remain the default C++ standard library, however if you wish
+libc++ to be the default one then set
+
+```python
+TARGET_CXXFLAGS_append_toolchain-clang ?= " -stdlib=libc++ "
+```
+
+in local.conf.
+You can select libc++ per package too by writing bbappends for them containing
+
+```python
+TARGET_CXXFLAGS_append_toolchain-clang = " -stdlib=libc++ "
+```
+
+# Building
+
+Below we build for qemuarm machine as an example
+
+```shell
+$ MACHINE=qemux86 bitbake core-image-minimal
+```
+# Running
+
+```shell
+$ runqemu qemux86
+```
+
+# Limitations
+
+Few components do not build with clang, if you have a component to add to that list
+simply add it to conf/nonclangable.inc e.g.
+
+```shell
+TOOLCHAIN_pn-<recipe> = "gcc"
+```
+
+and OE will start using gcc to cross compile that recipe.
+
+And if a component does not build with libc++, you can add it to conf/nonclangable.inc e.g.
+
+```shell
+TARGET_CXXFLAGS_remove_pn-<recipe>_toolchain-clang = " -stdlib=libc++ "
+```
+
+# Dependencies
+
+```
+URI: git://github.com/openembedded/openembedded-core.git
+branch: master
+revision: HEAD
+
+URI: git://github.com/openembedded/bitbake.git
+branch: master
+revision: HEAD
+```
+
+Send pull requests to openembedded-devel@lists.openembedded.org with '[meta-clang]' in the subject'
+
+When sending single patches, please use something like:
+
+'git send-email -M -1 --to openembedded-devel@lists.openembedded.org --subject-prefix=meta-clang][PATCH'
+
+You are encouraged to fork the mirror on [github](https://github.com/kraj/meta-clang/)
+to share your patches, this is preferred for patch sets consisting of more than
+one patch. Other services like gitorious, repo.or.cz or self hosted setups are
+of course accepted as well, 'git fetch <remote>' works the same on all of them.
+We recommend github because it is free, easy to use, has been proven to be reliable
+and has a really good web GUI.
+
+Layer Maintainer: [Khem Raj](<mailto:raj.khem@gmail.com>)