Updating stable branch later next week - Feb 2019


(Mishal Shah) #1

Later next week, we will be performing an update to the stable branch for swift-llvm, swift-clang, swift-compiler-rt, swift-lldb repositories.

We will be verifying the update on Swift CI with macOS and Ubuntu platforms.

For those supporting other platforms if you would like to test against the stable merge before it lands please check out the following branches:

swift:swift-5.1-branch (To be created)
swift-lldb:swift-5.1-branch (To be created)
swift-llvm:swift-5.1-branch
swift-clang:swift-5.1-branch
swift-compiler-rt:swift-5.1-branch
swift-libcxx:swift-5.1-branch
swift-clang-tools-extra:swift-5.1-branch

I will update this topic before we perform the operation.


(Jordan Rose) #2

A little more context for people who haven't been through this before:

  • Swift depends on LLVM and other repositories, which are themselves open source projects that get lots of updates on a day-to-day basis.

  • To avoid churn for Swift developers, we periodically cut release branches for LLVM etc. This does eventually form the version of LLVM used in a Swift release.

  • The "stable" branch for LLVM (that Swift's "master" branch builds against) is technically a different branch, but in practice it has the same content as "the latest release branch".

  • The operation that Mishal's going to perform is to move the "stable" branch of LLVM and others from swift-5.0-branch to swift-5.1-branch, and update Swift to build against this new content.

  • LLDB is extra complicated because it is from the LLVM project but also has parts that depend on Swift.

You can read more about this (from a Swift-repo-centric point of view) in docs/Branches.md.


(Mishal Shah) #3

Pull requests we are using to verify the merge