@dmajor, @tjr : The windows ABI already requires a touch on each stack page, so Windows shouldn't be affected, (not the case of the patch you're testing with, but should be the case in the near future). Basically it means that clang-cl will support
-fstack-clash-protection, but it should be a no-op for Windows.
@sylvestre: thanks for the feedback. Having firefox passing its validation with this patch is very good news. I've made several significant changes to the original patch, so an extra round may be needed, keep in touch.
@all: once the patch lands in llvm's master, I'll provide a backport if you want.