Name resolution and completion don't work with async_std/tokio/reqwest crates

Environment

• IntelliJ Rust plugin version: 0.2.109.2149-192
• Rust toolchain version: 1.39.0
• IDE name and version: Clion 2019.2.1
• Operating system: Ubuntu 19.10

Problem description

#[cfg(feature = "...")] in macros could not be found.

https://github.com/async-rs/async-std/blob/f611ceccc87aaf6b6cfb5bdee8bfffaffee5498f/src/utils.rs#L134-L144 https://github.com/async-rs/async-std/blob/f611ceccc87aaf6b6cfb5bdee8bfffaffee5498f/src/lib.rs#L203-L211

/// Declares std items.
#[allow(unused_macros)]
#[doc(hidden)]
macro_rules! cfg_std {
    ($($item:item)*) => {
        $(
            #[cfg(feature = "std")]
            $item
        )*
    }
}

cfg_std! {
    // ...
    pub mod task;
}

Steps to reproduce

The plugin cannot find the declaration of block_on to go. But it cound find after changing cfg_std! { pub mod task;} to #[cfg(feature = "std")]pub mod task; .

use async_std::task;

fn main() {
    task::block_on(async {
        println!("Hello, world!");
    })
}

[Undin]

It’s fixed in #4914 and will be landed in the next release (I hope). Note, intellisense features (name resolution, completion, etc) should work correctly only with new experimental macro expansion engine (see #3628). So, let’s keep this issue open until new macro expansion engine is enabled by default

[vlad20012]

The issue has been known for a long time. The new macro expansion engine (#3628) doesn’t solve it for now. Recently we discussed some possible solutions, so I’ll try to prototype something.