[llvm] [llvm] DLLExport public methods from SmallVector (PR #127850)

[Aaron Ballman via llvm-commits]

AaronBallman wrote:

> Before you do any further work on this project, please create a new discourse thread, which explains what the further plan for adding and maintaining these annotations is. There is a bunch of scattered discussion in various random pull requests, like #109702 or #113097. As this will be a sweeping, highly visible change across the entire codebase, it is important to have a central, up-to-date description of what is going on that further PRs can reference, and make sure that people are on board with your methodology before it starts getting implemented.

FWIW, this has already had an RFC on Discourse (https://discourse.llvm.org/t/supporting-llvm-build-llvm-dylib-on-windows/58891) as well as has a meta issue for tracking progress (https://github.com/llvm/llvm-project/issues/109483). I agree that it's a sweeping change, but I believe the buy-in already exists and this work has been ongoing for quite a while (at least in Clang, I'm less up-to-date on the LLVM side). This is a very important project for getting plugins to work on Windows, which is a significant use case for Clang (especially our tooling, like clang-tidy), so hopefully LLVM is willing to take on this functionality as well.

https://github.com/llvm/llvm-project/pull/127850