Reference

Installing clang 3.8 on Ubuntu 14.04.3.

Ubuntu14.04 clang3.8 Installation Guide

1.add the key:

$ wget -O - http://llvm.org/apt/llvm-snapshot.gpg.key|sudo apt-key add -

2.add the following line to /etc/apt/sources.list:

deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.8 main

3.install clang and lldb:

$ sudo apt-get update

$ sudo apt-get install clang-3.8 lldb-3.8

4.test:

$ clang-3.8 --version

clang version 3.8.0-2ubuntu3~trusty4 (tags/RELEASE_380/final)

Target: x86_64-unknown-linux-gnu

Thread model: posix

InstalledDir: /usr/bin

2017.10