(lib/IDE) @_documentation attribute always crashes sourcekit-lsp

[tayloraswift]

using the @_documentation attribute always crashes sourcekit-lsp on the 5.8 branch.

@_documentation(visibility: public)
enum E
{
}

both @_documentation(visibility:) and @_documentation(metadata:) are affected, as well as both quoted and un-quoted metadata forms.

it appears to trip this assertion in lib/IDE/SyntaxModel.cpp:

sourcekit-lsp: /home/build-user/swift/lib/IDE/SyntaxModel.cpp:1343: auto (anonymous namespace)::ModelASTWalker::handleAttrRanges(ArrayRef<(anonymous namespace)::ModelASTWalker::DeclAttributeAndRange>)::(anonymous class)::operator()(swift::SourceRange) const: Assertion `(TokenNodes.empty() || SM.isBeforeInBuffer(AttrRange.End, TokenNodes.front().Range.getStart())) && "AttrRange doesn't align with any TokenNode?"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.

this happens on swift-5.8-DEVELOPMENT-SNAPSHOT-2023-02-23-a.

$ swift --version
Swift version 5.8-dev (LLVM 44d4f9d4b49845f, Swift b9562e1a860ec0b)
Target: x86_64-unknown-linux-gnu

[QuietMisdreavus]

I opened #64326 which fixes a crash, though it's not the same assertion as your message. I'm building a Linux toolchain on that PR; if it succeeds, would you be willing to test it out for me?

[tayloraswift]

if it is an Amazon Linux 2 toolchain, yes!

[QuietMisdreavus]

Looks like Swift CI builds an Ubuntu toolchain on its Linux builder. 😕 Still, the archive is here: https://download.swift.org/tmp/pull-request/64326/384/ubuntu2004/PR-ubuntu2004.tar.gz