x/tools/gopls: support Go assembly files

[adonovan]

Gopls already supports navigating from Go source to assembly files (use "Go to definition" on a func declaration with no body), but it wouldn't be hard for it to support navigation within assembly files, and from assembly files to Go files. The necessary parts are:

• a new file.Kind for Asm (see https://go.dev/cl/649461 for sketch) and go.s LanguageID.
• a basic parser for assembly files that can extract symbol names and control labels reliably.
• recording of parsed assembly files in cache.Package, analogous to CompiledGoFiles.
• augmentation of the xrefs index to include cross-package references from assembly files.
• new implementations of the Definitions and References queries for file.Asm.
• bonus: an implementation of Hover for assembly could provide all kinds of helpful information to make reading easier.
• bonus: DocumentHighlight could show, for a given register, its def/use chains by making them temporarily bold.
• go.s languageID support in eglot, vscode-go, neovim.

This is obviously not a high priority, but it's a fun little project.

@golang/compiler @golang/runtime

[gopherbot]

Change https://go.dev/cl/649461 mentions this issue: gopls/internal/cache: rudimentary support for Go *.s assembly

[gabyhelp]

Related Issues

• x/tools/gopls: new CodeAction: "Show arm64 assembly for function f..." #67478 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[gopherbot]

Change https://go.dev/cl/654335 mentions this issue: gopls/internal/util/asm: better assembly parsing

[groot-guo]

Hello, I'd like to try to take on this task.

[adonovan]

Hello, I'd like to try to take on this task.

Thanks for offering. I suggest you start with the first (unchecked) bullet point in its own CL.