How to setup icecream to compile mozilla-central on mac and linux

All the files/scripts below can be found in this repository.

At time of writing, brew installs llvm/clang 8.0 (clang version 8.0.0 (tags/RELEASE_800/final))

Make sure you are running the latest version of icecream

Ubuntu prior to 18.04 shipped an old icecream version released in 2013: version 1.0.1. Upgrade to Ubuntu 18.04 or you will find the latest release (1.1) packages for ubuntu/debian in the packages directory.

Getting icecream installed and running on Mac

$ brew install icecream

start iceccd with:

$ brew services start icecream

You can set the scheduler to use if auto-discovery doesn't work:

$ $EDITOR ~/Library/LaunchAgents/homebrew.mxcl.icecream.plist

In that file replace HOSTNAME_SCHEDULER with the hostname the icecc scheduler is running on.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>homebrew.mxcl.icecream</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/local/opt/icecream/sbin/iceccd</string>
        <string>-s</string>
        <string>HOSTNAME_SCHEDULER</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

$ brew services restart icecream

Getting llvm installed and running on Mac

$ brew install llvm

Getting toolchain packaged for icecream

You can directly download the archives here and skip the rest of this section. https://github.com/jyavenard/mozilla-icecream/raw/master/clang-7.0.0-Darwin17_x86_64.tar.gz and: https://github.com/jyavenard/mozilla-icecream/raw/master/clang-7.0.0-x86_64.tar.gz

Get the latest mac clang build at http://releases.llvm.org/download.html

Current it’s 8.0.0 available at: mac: https://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-apple-darwin.tar.xz linux 64 bits: https://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz (tested with ubuntu 18.04 only)

In the following instructions, I placed everything into ~/clang for ease of documentation, you can of course place it in any location.

On mac:

$ mkdir ~/clang
$ cd ~/clang

Extract the archive and create the icecream toolchain archive

$ wget https://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-apple-darwin.tar.xz
$ tar xvf clang+llvm-8.0.0-x86_64-apple-darwin.tar.xz
$ /usr/local/bin/icecc-create-env --clang ~/clang/clang+llvm-8.0.0-x86_64-apple-darwin/bin/clang /usr/local/Cellar/icecream/1.2_1/libexec/icecc/compilerwrapper

this will create a file such ce3126a6676d8b9cd58ea709615bee97.tar.gz rename it into clang-8.0.0-Darwin17_x86_64.tar.gz

On Linux

$ mkdir ~/clang
$ cd ~/clang

Extract the archive and create the icecream toolchain archive

$ wget https://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz
$ tar xvf clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz
$ /usr/lib/icecc/icecc-create-env --clang ~/clang/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04/bin/clang /usr/lib/icecc/compilerwrapper

import the generated tar.gz into your mac and rename it as clang-8.0.0-x86_64.tar.gz, place it into ~/clang

Configure your mozbuild for using icecream

There are two ways to configure the required ICECC_VERSION / ICECC_CC / ICECC_CXX, set the value in your $HOME/.profile or directly within the .mozconfig. I chose the later. The primary reason for this is related to my use of Visual Studio Code. There's a bug in VSCode C++ module that prevent symbols search to properly work (see microsoft/vscode-cpptools#1251)

Those are the .mozconfig that I use:

On Mac

# -j4 allows 4 tasks to run in parallel. Set the number to be the amount of
# cores in your machine. In Paris or Toronto use -j100
mk_add_options MOZ_MAKE_FLAGS="-s -j44"
mk_add_options AUTOCLOBBER=1

# Enable debug builds
ac_add_options --enable-debug
ac_add_options --enable-debug-symbols

# Turn off compiler optimization. This will make applications run slower,
# will allow you to debug the applications under a debugger, like GDB.
ac_add_options --disable-optimize

#enable FFmpeg code
ac_add_options --enable-ffmpeg

#Malloc debug
#ac_add_options --disable-jemalloc

#ac_add_options --with-ccache=/usr/local/bin/ccache
#mk_add_options 'export RUSTC_WRAPPER=sccache'
mk_add_options 'export CARGO_INCREMENTAL=1'

mk_add_options "export ICECC_VERSION=x86_64:$HOME/clang/clang-8.0.0-x86_64.tar.gz,Darwin17_x86_64:$HOME/clang/clang-8.0.0-Darwin17_x86_64.tar.gz"
mk_add_options "export ICECC_CC=/usr/local/opt/llvm/bin/clang"
mk_add_options "export ICECC_CXX=/usr/local/opt/llvm/bin/clang++"

CC="/usr/local/opt/icecream/libexec/icecc/bin/clang --target=x86_64-apple-darwin16.0.0 -mmacosx-version-min=10.11"
CXX="/usr/local/opt/icecream/libexec/icecc/bin/clang++ --target=x86_64-apple-darwin16.0.0 -mmacosx-version-min=10.11"

On Linux

# -j4 allows 4 tasks to run in parallel. Set the number to be the amount of
# cores in your machine. In Paris or Toronto use -j100
mk_add_options MOZ_MAKE_FLAGS="-s -j44"
mk_add_options AUTOCLOBBER=1

# Enable debug builds
ac_add_options --enable-debug
ac_add_options --enable-debug-symbols

# Turn off compiler optimization. This will make applications run slower,
# will allow you to debug the applications under a debugger, like GDB.
ac_add_options --disable-optimize

#Malloc debug
#ac_add_options --disable-jemalloc

#ac_add_options --with-ccache=/usr/local/bin/ccache
#mk_add_options 'export RUSTC_WRAPPER=sccache'
mk_add_options 'export CARGO_INCREMENTAL=1'

mk_add_options "export ICECC_VERSION=x86_64:$HOME/clang/clang-8.0.0-x86_64.tar.gz"
mk_add_options "export ICECC_CC=/usr/bin/clang-6.0"
mk_add_options "export ICECC_CXX=/usr/bin/clang++-6.0"

CC="/usr/lib/icecc/bin/clang --target=x86_64-pc-linux-gnu"
CXX="/usr/lib/icecc/bin/clang++ --target=x86_64-pc-linux-gnu"

Start the build

You may find that only using the remote linux host makes your compilation much quicker, to do so, remove the Darwin17_x86_64 entry from ICECC_VERSION:

ICECC_VERSION="x86_64:$HOME/clang/clang-8.0.0-x86_64.tar.gz" ./mach build -j32

A note of caution, the paths in ICECC_VERSION can't be symbolic links.