Shadowed macro causes macro-error

[vallentin]

The first foo!(1); uses to the subsequent shadowed macro_rules! foo. Causing expected leaf: `,` rust-analyzer(macro-error). Performing "Go to Definition" confirms this, as the cursor jumps to the second macro_rules! foo.

fn main() {
    macro_rules! foo {
        ($a:expr) => {};
    }

    foo!(1);

    macro_rules! foo {
        ($a:expr, $b:expr) => {};
    }

    foo!(1, 2);
}

This issue must have been introduced lately, as a few weeks ago this was not an issue.

Issue exists on both stable and the latest nightly release:

• rust-analyzer version: 2020-12-28 (1d53075)
• rust-analyzer version: nightly (77ad203)

[edwin0cheng]

triage: I can't reproduce in current master 8584d26.

@vallentin Would you mind to try it again ?

[vallentin]

It still occurs on the latest releases. However, that's of course prior to 8584d26. Can I easily obtain a build, that doesn't require me building rust-analyzer? 😅

rust-analyzer version: 2021-01-04 (5b86ff3)
rust-analyzer version: nightly (a3e5dcc)

[lnicola]

@edwin0cheng 8584d26 isn't on master, you meant #7145.

@vallentin not really, you'd need to wait until tomorrow. Building from source isn't that hard, though.

(I can't reproduce it either)

Also, that's a lovely issue report, I wish we had more of these.

[edwin0cheng]

Sorry, @lnicola is right and I meant #7145.

However, I tried a3e5dcc and 5b86ff3, I can't reproduce the errors too, so ... What os and ra settings you are using ?

Also, that's a lovely issue report, I wish we had more of these.

Indeed

[vallentin]

It wasn't the difficulty, it's more that I'm expecting a clean build to take quite a bit of time.

I'm running Windows 10. I tested the above using only default settings, with the exception of "rust-analyzer.updates.channel": "nightly" to test the nightly release.

[flodiebold]

A clean release build takes about 5 minutes.

[vallentin]

Just under 3 minutes, nice. Alright, so I've just tried using #7145. Sadly, the issue still persists.

Checking "Show RA Version" show the expected commit. So I sadly don't think that fixes this issue.

rust-analyzer version: 2021-01-04 (76f2b9d)

[flodiebold]

I can't reproduce the error in current master either, and changing the second macro definition to take just one argument does cause an error only in the second call; though it's worth noting that goto definition, hover etc. refer to the wrong macro for the first definition.

[vallentin]

Hmm, that's odd. I assume you aren't using Windows then?

However, I don't at all see how this would be affected by OS, so it's rather confusing.

Is there any more information I can provide?

---

Here's step-by-step what I do to reproduce the issue (on Windows 10):

git clone https://github.com/rust-analyzer/rust-analyzer
cd rust-analyzer
cargo build --release
cp target/release/rust-analyzer.exe ~/AppData/Roaming/Code/User/globalStorage/matklad.rust-analyzer/rust-analyzer-x86_64-pc-windows-msvc.exe

cd ..
cargo new foo
code foo

Then paste the following code in src/main.rs.

fn main() {
    macro_rules! foo {
        ($a:expr) => {};
    }

    foo!(1);

    macro_rules! foo {
        ($a:expr, $b:expr) => {};
    }

    foo!(1, 2);
}

Checking "Show RA Version" correctly shows:

rust-analyzer version: 2021-01-04 (903d1f8)

---

Here's a screenshot showing both the issue and the version:

(All default settings.)

[flodiebold]

Oh, putting all that code into main makes a big difference. Local definitions are mostly not supported yet.

[vallentin]

I literally just had the same thought pop into my head after commenting. Now I feel silly!

How come this worked previously?

[flodiebold]

It didn't, we just didn't emit those macro errors until recently.

[lnicola]

That's #1559.

[vallentin]

Is there any way to suppress that error?

I have a few files that are affected by this change. Which prevents any other errors from being detected.

[flodiebold]

You can add "macro-error" to the rust-analyzer.diagnostics.disable setting.

This shouldn't prevent other errors from being detected though.

[vallentin]

Thanks!

The files where the issue occurs in conjunction are quite big. I'll look into making a MCVE, and post it if/when I'm able to.

[jonas-schievink]

Triage: Still happening, presumably because we don't really handle legacy macro scopes in Resolver

[lnicola]

This works now AFAICT.

[Veykril]

🤨 oh it does, but why/how?