Hello, In light of the fact that we've switched to clang-cl for our Windows builds[1], we are planning to drop support for compiling Firefox with MSVC in the near future[2]. Our estimate is that this will happen sometime in Q1. Supporting more than one compiler is a maintenance burden and we've already seen developers spend considerable time getting their patches that work with clang-cl to build with MSVC. We are currently blocked by the fact that our aarch64-windows builds are still using MSVC and we are waiting on upstream clang-cl work to switch those builds to clang-cl. Once that takes place we no longer have a compelling reason to continue supporting MSVC.
To preempt the question--when this happens we intend to make MSVC error in configure, and not just move MSVC to Tier 3 "patches welcome" status. Our reasoning is that Tier 3 configurations still create work: developers spend time building in those configurations, and lack of CI coverage means that when they inevitably break they waste time trying to fix things. Bugs get filed, and other developers waste time trying to help or reviewing patches to fix things. Explicitly unsupporting MSVC is the best way for us to convey the fact that developers should not be using it and we will not accept patches to fix issues that only affect MSVC. If you have specific reasons for continuing to use MSVC please let us know. If there are deficiencies in clang-cl compared to MSVC we should get them filed and fixed. Thanks, -Ted 1. https://bugzilla.mozilla.org/show_bug.cgi?id=1443590 2. https://bugzilla.mozilla.org/show_bug.cgi?id=1512504 _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform