Duplicate references in wasm_bindgen types

[abseee]

When I issue a textDocument/references request on MyStruct in lib.rs, I expect 3 references. Instead I get 288! VSCode seems to dedupe these results before surfacing them in the UI but other editors may not. Dupes are also returned for MyEnum and its variants. Non-wasm-bindgen tagged types work fine; presumably other macros also trigger this issue but I don't know enough to debug further.

VSCode <-> Rust analyze trace
Expanded lib.rs

rust-analyzer version: 0.3.1238-standalone

rustc version: rustc 1.63.0 (4b91a6ea7 2022-08-08)

[vimalk78]

I am seeing same issue in nvim

[vimalk78]

i just upgraded to latest master and this issue is super annoying.
do we know which commit caused this? i would want to revert from latest master. Is there a way to de-dup in nvim?

[Veykril]

This behavior is there for at least a year judging from the commits (if not longer), fix is adding a .unique() after this here

rust-analyzer/crates/ide/src/references.rs

Line 88 in 067c410

.map(|file_ref| (file_ref.range, file_ref.category))

[vimalk78]

wow, is this something that editors need to take care of, and fixing it in rust-analyzer will cause additional issues?

[Veykril]

No, we can easily fix this in r-a, and I think it makes sense to do so as well. Though I would expect clients to dedup this as well.

[vimalk78]

shall i test it and open a PR?

[Veykril]

You are more then welcome to!

[abseee]

FWIW I bisected the issue to ebfbb31

[lnicola]

That's not right. Prior to that commit, proc macros didn't work on your rustc version.

[lnicola]

You can use the expansion output directly if you want to bisect it further.

[abseee]

Ah I thought VS Code would show a warning if the proc_macros weren't expanded in rust-analyzer. Was I supposed to build r-a with a matching older version of rustc? Unfortunately I can't repro the duplicate references in the macro expanded source file.

[lnicola]

Ah I thought VS Code would show a warning if the proc_macros weren't expanded in rust-analyzer.

I think it should print an error in the logs, at least, not sure when that was added. You can check by running Expand macro, if that's easy to do from Helix.

Was I supposed to build r-a with a matching older version of rustc?

No, you need to change your project toolchain (rustup override or rustup default) to a supported version. The RA build version doesn't matter.