rtags-install-insns.org

wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
sudo apt-add-repository "<relevant 'deb http://...' text from https://apt.llvm.org>"
sudo apt update
sudo apt install clang-<latest-version>
sudo apt install libclang-<latest-version>-dev
# may need to install llvm-<latest-version>, llvm-<latest-version>-runtime

Also may have to fix what llvm-config points to. Do this.

sudo ln -s /usr/lib/llvm-<latest-version>/bin/llvm-config /usr/local/bin/llvm-config

# Commands in Ubuntu terminal
git clone --recursive https://github.com/Andersbakken/rtags.git
cd rtags
cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=1 .
make
sudo make install

Note that you may have to create a symbolic link sudo ln -s `which llvm-config-<latest-version>` /usr/local/bin/llvm-config for llvm-config to be found.

Configure a service in systemd

Create RTags daemon socket service configuration file

add the following file to /etc/systemd/user/rdm.socket (alt. ~/.config/systemd/user/rdm.socket)

[Unit]
Description=RTags daemon socket

[Socket]
ListenStream=%h/.rdm

[Install]
WantedBy=multi-user.target

Create the RTags daemon service configuration file

add the following to /etc/systemd/user/rdm.service (alt. ~/.config/systemd/user/rdm.service)

[Unit]
Description=RTags daemon

Requires=rdm.socket

[Service]
Type=simple
ExecStart=/usr/local/bin/rdm --log-file=%h/.rtags/rdm.log --data-dir=%h/.rtags/rtags-cache --verbose --inactivity-timeout 300

Enable the socket service

systemctl --user enable rdm.socket
systemctl --user start rdm.socket

Configuring use with gcc and non-cmake build systems

After rtags’ install you should have a script gcc-rtags-wrapper.sh script somewhere on path. You will need to use this wrapper to properly invoke gcc, g++ for use with rtags. To do this run:

for c in cc c++ gcc g++; do
 ln -s `which gcc-rtags-wrapper.sh` "$HOME/.local/bin/$c";
done

Note you may need to add the line

export PATH="$HOME"/.local/bin:$PATH

at the end of your .bashrc and potiential run mkdir ~/.local/bin prior to the for loop.

This should make invocations of gcc, g++ to use a symlink to the gcc wrapper script. Just make sure $HOME/.local/bin appears first on path.

To confirm this run

which -a g++

which should response with

$HOME/.local/bin/g++
/usr/bin/c++

(note that you may need to run hash -r first before running this check for bash to clear cache)

Build an RTags database for your project

just create a compile_commands.json file then use RTags to index your code

rc -J ./compile_commands.json

note that you may first need to run rdm &

https://eklitzke.org/using-emacs-and-rtags-with-autotools-c++-projects

has more info

also note that rtags will not work for projects under the /tmp directory.