Install LLVM/Clang in Linux/Ubuntu using git

Step 1: 
Download LLVM and Clang

git clone http://llvm.org/git/llvm.git llvm cd llvm/tools git clone http://llvm.org/git/clang.git clang

Step 2: 
Configure and install LLVM and Clang

cd ../ mkdir build  (for building without polluting the source directory) cd build ../configure --enable-optimized --enable-assertions                                 --prefix=/home/user/llvm/install make make install

for more information about configure and install see. Getting Started with the LLVM System

Step 3: 
Testing LLVM/Clang, compile small C++ program (test.cpp)

// test.cpp #include <iostream> using namespace std; int main(int argc, char *argv[]) {   cout << "Hello LLVM/Clang" << "\n";   return 0; }

Step 4: 
Run

/home/user/llvm/install/bin/clang++ test.cpp -o hello ./hello

Output:

Hello LLVM/Clang