With the current 5.0.0svn version we're bootstrapping, we hit a build failure with the new VC++ v14.12 toolset shipping in VS2017 15.5: C:\PROGRA~2\MIB055~1\2017\COMMUN~1\VC\Tools\MSVC\1412~1.258\include\type_traits:898:47: error: '_Ty' does not refer to a value Which in turns leads to a Rust panic and build failure. I've confirmed locally that updating to SVN tip (r319785) fixes this failure and allows me to build again. I'll work on cleaning up the patch a bit and more thoroughly test it with all our different build variants so we can make this the new default and unblock Visual Studio upgrades.

As an update, I tried a build off SVN rev 317840 (same as what we're using for Linux ASAN builds), and while it mostly seems to work OK on Try (and successfully builds m-c locally), I'm seeing Win32 static analysis build failures: https://treeherder.mozilla.org/logviewer.html#?job_id=150042241&repo=try Win64 builds are fine. Newer SVN revisions hit other static analysis bustage in clang-plugin.dll, but dmajor has a tentative fix that I'll try pushing on top of tomorrow.

This is the same revision we're currently using for Linux ASAN builds. Confirmed locally that this fixes the build issues with VS2017 15.5. https://treeherder.mozilla.org/#/jobs?repo=try&revision=bfe9d8401b8e6922238b2e3e65b12e4225a23074&group_state=expanded

Pushed by ryanvm@gmail.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/9072ae5dd4f8 Update clang-cl builds to LLVM revision 317840. r=ted