chromium_iconEarlier this week, Google released a security update for its chrome/chromium browser. The new version 62.0.3202.62 plugs the holes of 35 more or less serious issues, several of them have a CVE rating.
When the topic of Chromium 62 came up in the comments section of a previous post, I mentioned that I was unable to compile it on Slackware 14.2. Errors like “error: static assertion failed: Bound argument |i| of type |Arg| cannot be converted and bound as |Storage|” yield some results when looked up on the Internet, and they indicate that Slackware’s own gcc-5.3.0 package is too old to compile chromium 62.
The c++11 implementation in gcc-5.3.0 has issues which are fixed in gcc-5.4.0. Unfortunately we are stuck with what we have on Slackware 14.2; it will only get security fixes, no functional upgrades, so no gcc-5.4.0.

I posted on the chromium-packagers discussion group to see if there’s anything to be done about this and that lead to an e-mail discussion with a Google developer who is also a Slackware user. He told me that Google compiles its own Chrome with clang, and more specifically, using a modified bleeding-edge version of clang that does what Google wants it to do. Compiling with gcc is not tested all that much, which apparently is leading to a multitude of reports about gcc related compilation issues. It’s not just me.

There is a reason that I want to compile with gcc, even though the chromium.SlackBuild already has some (hopefully complete) support for using clang instead. Google does not want to use the system-clang of the distro and instead, forces a download of its own clang binaries. I am not ready to trust a binary black-box to compile my chromium package… after all I created the chromium package for Slackware so that we do not have to depend on Google’s Chrome binaries.
This entry on Google’s  reviewboard is encouraging though; there is an initiative to take distro packagers’ wishes more seriously. The idea is to work toward using the system toolchain to compile Google’s clang variant from source and then use that to compile chromium. I’ll wait for that to happen before I switch to clang. I have nothing against clang as compared to gcc – it’s only my unease at having to trust someone else’s binaries.
I hear you say “but what about NaCl?”… indeed in order to compile NaCl my chromium.SlackBuild is already downloading a binary toolchain from Google. But that downloaded PNaCl toolchain is not used to compile the complete browser, it’s used only for the NaCl sandbox. And even that is coming to an end. Google has deprecated (P)NaCl in favor of WebAssembly. As of April 2018, it will only support PNaCl in Chrome Apps and Extensions. Meanwhile, WebAssembly (a portable cross-platform and cross-browser solution for presenting web apps at near-native speed) is already fully functional in Chrome/Chromium, as can be seen by visiting http://webassembly.org/demo/

Back to the present day. I still needed to compile chromium 62 for Slackware 14.2 with its too-old compiler suite. Therefore I grabbed my gcc5.SlackBuild which I had originally meant to be installed alongside gcc7 on slackware-current. I polished it a wee bit, and then build packages for Slackware 14.2. My ‘gcc5‘ works by sourcing its “/etc/profile.d/gcc5.sh” script which sets several environment variables and points those to the gcc5 binaries (CC, CPP, GXX, AR, NM, RANLIB). Unfortunately, the chromium framework ignores these environment variables and uses the “which” command to look for gcc and g++. Therefore I had to be a bit more creative (i.e. break some stuff).

So, what is the drill on Slackware 14.2 if you want to compile Chromium 62?

  • Install gcc5, ninja and nodejs for which I have packages in my repository. Note that installing this ‘gcc5’ does not replace your Slackware gcc-5.3.0, it gets installed alongside and does not clash.
  • Download the chromium sources and scripts from my repository.
  • Make the ‘gcc’ and ‘g++’ symlinks in Slackware point to the ‘gcc5’ binaries:
    # cd /usr/bin
    # mv gcc gcc.orig
    # ln -s gcc-5 gcc
    # mv g++ g++.orig
    # ln -s g++-5 g++
  • Source the profile script (just to be sure). Note the ‘dot’ at the beginning, that dot is the ‘source’ command:
    # . /etc/profile.d/gcc5.sh
  • Compile chromium. Note that this requires lots of RAM and lots of diskspace, and if your CPU does not have many cores, you’ll need a lot of time too.
  • Restore Slackware’s gcc and g++ symlinks:
    # cd /usr/bin
    # mv gcc.orig gcc
    # mv g++.orig g++

Fortunately gcc5, ninja and nodejs are only needed for the compilation, not for actually running the browser. So if you do not fancy a re-compilation, you do not have to install any of those other packages.

The packages for chromium are available for Slackware 14.2 and -current in my repository or one of its mirrors:

Have fun! Eric