Homebrew is a package manager for macOS. You can use it to install the Arm GCC toolchain:
brew tap ArmMbed/homebrew-formulae
brew install arm-none-eabi-gcc
We update this tap with new releases of the toolchain whenever they become available.
This tap is maintained by the Arm Mbed team, not the Arm OSS compiler team! Please raise issues with this formula here, and issues with the toolchain here.