As part of our work with Tor, we’ve been working on getting a MinGW-based build of Windows into TaskCluster. Tor is currently using ESR releases, and every ESR they have to go through a large amount of work to get the build working under MinGW again; by continually building (and testing) that build we’ll be able to cut weeks to months of effort for them each ESR release. (Not breaking the MinGW build is also a necessity if they were ever to move off ESRs.)
Unlike our normal Windows builds with msvc or clang-cl, this is a cross-compile on Linux for Windows, as well as the first time in a long time we’ve built for Windows with gcc. Building with gcc for Windows has exposed a number of new warnings <https://bugzilla.mozilla.org/show_bug.cgi?id=1394433> to clean up, as well as some C++ spec incompatibilities that MSVC (and clang-cl) accept. All of the breaks have been resolved; and a lot of the warnings and similar are either resolved or in-progress. Effective this weekend, MinGW is on Treeherder, with the single build target win32-mingw32 (debug). Its toolchain builds are under TMW (with a few under TL because they are generic Linux packages.) The one-click loaner system works for MinGW, and we’re going to allow this to bake at Tier 2 for a while. Your help in keeping the build green is greatly appreciated, and if you hit a MinGW bug you can’t decipher, I’ll be happy to help, just send me an email or a needinfo. Some of the most common things that cause errors for MinGW: - #include <Windows.h> instead of #include <windows.h> and similar - _uuidof() instead of IID_* ref <https://stackoverflow.com/questions/18606546/how-to-use-uuidof-in-mingw> - Casting nullptr to bool or int - Using the (in)correct assembly code - Breaking --disable-webrtc, --disable-sandbox, or --disable-accessibility - MinGW lagging behind on defining new constants Microsoft has defined There are a few things left outstanding <https://bugzilla.mozilla.org/showdependencytree.cgi?id=1330608&hide_resolved=1> for the MinGW build, including webrtc <https://bugzilla.mozilla.org/show_bug.cgi?id=1393901>, stylo <https://bugzilla.mozilla.org/show_bug.cgi?id=1390583> (which may be the most difficult in this list), the sandbox <https://bugzilla.mozilla.org/show_bug.cgi?id=1230910>, --enable-accessibility <https://sourceforge.net/p/mingw-w64/bugs/648/>, cleaning up warnings <https://bugzilla.mozilla.org/show_bug.cgi?id=1394433>, and running tests <https://bugzilla.mozilla.org/show_bug.cgi?id=1395047>. In the future, there is hope (by me at least) to throw all of this work away. Compiling on Linux for Windows with clang (or clang-cl) would probably be a significant improvement for Tor’s builds, and would enable them to take advantage of CFI and SEH, as well as simplifying the number of platforms Mozilla supports. Chrome has been pushing towards this <https://bugs.chromium.org/p/chromium/issues/detail?id=495204>, so we’re keeping an eye on their progress. Finally, I want to thank everyone who brought this long process to this point: everyone who wrote patches, explained things (sometimes over and over again), and reviewed. That’s including but not limited to: boklm, dmajor, froydnj, glandium, georg, jacek, jrmuizel, and ted; plus the dozen or so more people who have reviewed my patches all over the codebase. -tom _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
