Distcc With MSVC
distcc, distributed compilations for C/C++ compilers.
The goal of this project is to speed up Windows Mozilla Builds by spreading object compilations over several machines. This can be done by using an open source product called distcc created by Martin Pool. Unfortunately this is only available on *nix machines using gcc. Our project involves porting this software to Windows and use Microsoft's Visual C++ compiler using cygwin.
We have stuff for you to do!
- Dave Liebreich - Thanks for checkin whether cygwin's ln will create working links to cl.exe (e.g. a link name clfoo.exe to cl.exe).
- Ben Hearsum - for the windows box and support! Thank you!
- Jason Spiro - For helping figure out why cl wouldn't execute in the unit testing framework and assisting in finding the right path to solve this issue.
Mozilla (and others :) ) is interested in speeding up their builds by using a distributed compiler (distcc). The problem is that distcc only works with gcc but not with the msvc compiler (cl).
The plan has two stages:
- change distcc to support multiple compilers
- add cl support
Initially, we planned to use two vtables (one for distcc and another for distccd) to keep track of which compiler specific operation to use when. However that bombed out so we're currently using a single vtable.
We have kept the two vtable branch because we actually got a lot of the cl specific stuff done (before we realized we missed some functions).
The First Patch (Oops)
This was released to the distcc mailing list. This has a few functions missing. It was meant to provide the two vtable support without cl. It should be ignored and we'll be re-releasing a working version of this soon.
For the most up to date info look up foobartastic
Nov 6. 2006
There is a scheduled 'hack day' being set up. Were putting it at every tuesday at around 5:20 in the TEL open lab.
Nov 2. 2006
After a haitus from touching distcc, we battled the serpent of the C (haha) once again and retreated with our lives, barely, but lost our ego and motivation (at least Cesar did). We cleared up a path setting bug that caused CL to die and return a bad return value. Then we (eventually) passed ParseHost case, which parses an environment variable for ip addresses and domain names. A inproperly done svn merge wasted a good few hours on that.
We also created safeguards, so that any unimplemented vtable function that is called will throw an error message instead of having a segmentation fault.
Oct 20. 2006
We have a usable windows box for doing our msvc testing (finally!). Thanks to User:Bhearsum for the boxes.
Oct 12. 2006
Argh. I have been trying to build firefox using distcc for about 2 weeks, with many small details getting in the way. At one point things were working, but than it stopped and I don't know why. I finally, at one point, got things to build on andrew's machine. But the build failed complaining about (this is one of the many, many things) undefined reference operator delete(void*). I think it might be because distcc is calling gcc rather than c++. I changed the MOZCONFIG to use CC='distcc gcc' and CXX='distcc g++'. This threw me this ugliness :
make: warning: jobserver unavailable: using -j1. Add `+' to parent make rule.
Which I told reed about, but has never came across this problem. One nasty solution is to use -j without specifing a number to allow unlimited jobs. At least it's working.
In other news, Tom sent a patch.
Oct. 2 2006
A preliminary test of running distcc in cygwin revealed we were failing 4 tests; one or two more than our first patch. We tried to fix it, but never had success and didn't issue a commit. A while later we try running distcc again on another machine. This time we were only failing one test, which is less than our first patch. Here is the known tests to fail
- EmptySource_Case --- This is expected to fail since this is a bug in the earlier gcc compiler.
The explination for the extra three preliminary tests failing is because we interupted one of the tests, which we believed caused the daemon to be orphaned and exacting it's revenge on the murder's of it's parent processes.
Sept. 26 2006
Tried to do parallel builds with mozilla in linux (maybe we should have done this first). Here is something usefull to know : To parallel build in mozilla, you cannot pass the -jN option to make and expect it to work. It didn't for me, and make was killing itself without an explination. I later learned that you have to add the following line to mozconfig
Sept. 24 2006
We think we've got the architecture right now. Ofcourse the only way to know is to start porting cl :). We're now going to try to port the tests to work with cl.exe.