Build Clang 12 with Meson and conan Ubuntu 20.04

script.sh

#! /bin/bash

echo "install requires tools"
sudo apt-get update
sudo apt-get install -y cmake libffi-dev libedit-dev swig git gcc g++ pkg-config ninja-build libxml2-dev python3-pip

echo "Download llvm source"
git clone --depth 1 https://github.com/llvm/llvm-project
cd llvm-project

ln -s clang-tools-extra clang/tools/extra

dir=$PWD
echo "Build LLVM\n"
cd $dir
mkdir build
cd $dir/build
CC=gcc CXX=g++ cmake -G "Ninja" \
    -DCMAKE_BUILD_TYPE=Release \
    -DLLVM_TARGETS_TO_BUILD="host;AMDGPU;BPF" \
    -DLLVM_BUILD_LLVM_DYLIB=ON \
    -DLLVM_LINK_LLVM_DYLIB=ON \
    -DLLVM_ENABLE_FFI=ON \
    -DLLVM_ENABLE_RTTI=ON \
    -DLLVM_BUILD_DOCS=OFF \
    -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;compiler-rt;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;polly;" \
    -DCMAKE_INSTALL_PREFIX=/usr ../llvm
ninja
sudo ninja install/strip

echo "Install meson"
pip3 install meson

echo "download conan deb"
cd ~
wget https://dl.bintray.com/conan/installers/conan-ubuntu-64_1_29_1.deb
sudo dpkg -i ~/conan-ubuntu-64_1_29_1.deb
rm ~/conan-ubuntu-64_1_29_1.deb

echo "Setup conan profile"

conan config init
cat <<EOT >> ~/.conan/profiles/clang 
[settings]
os=Linux
os_build=Linux
arch=x86_64
arch_build=x86_64
compiler=clang
compiler.version=12
compiler.libcxx=libc++
build_type=Debug
[options]
[build_requires]
[env]
CXX=clang++
CC=clang
EOT