Ignore generated fresh lifetimes in elision check

[oxalica]

fixes #3988

changelog: Ignore generated fresh lifetimes in elision check.

HELP: It seems tests/ui are compiled under edition 2015, and I don't know how to add tests for this properly.

Here is the test input it had already passed:

#![feature(async_await)]
#![allow(dead_code)]

async fn sink1<'a>(_: &'a str) {} // lint
async fn sink1_elided(_: &str) {} // ok

async fn one_to_one<'a>(s: &'a str) -> &'a str { s } // lint
async fn one_to_one_elided(s: &str) -> &str { s } // ok
async fn all_to_one<'a>(a: &'a str, _b: &'a str) -> &'a str { a } // ok
// async fn unrelated(_: &str, _: &str) {} // Not allowed in async fn

// #3988
struct Foo;
impl Foo {
    pub async fn foo(&mut self) {} // ok
}

// rust-lang/rust#61115
async fn print(s: &str) { // ok
    println!("{}", s);
}

fn main() {}

[phansch]

HELP: It seems tests/ui are compiled under edition 2015, and I don't know how to add tests for this properly.

I think you can add the following to the top of the UI test file to use the 2018 edition:

// compile-flags: --edition 2018

[oxalica]

I think you can add the following to the top of the UI test file to use the 2018 edition:

// compile-flags: --edition 2018

Thanks, it works. Tests are now added.

[flip1995]

Hmm, now util/dev fmt can't deal with the 2018 edition 🤔

[flip1995]

Adding edition = "2018" here

rust-clippy/rustfmt.toml

Line 5 in e5f2330

should solve this.

[oxalica]

Adding edition = "2018" here

rust-clippy/rustfmt.toml

Line 5 in e5f2330

should solve this.

Setting global fmt edition will cause some tests failed.
Is there any way to skip fmt on one file? #[rustfmt::skip] not works here.

[flip1995]

I think using Edition = 2018 and fixing the falling test would be the best thing to do here.

[flip1995]

Thanks! You fixed the first T-async-await issue 🎉

@bors r+

[bors]

📌 Commit 5265ab8 has been approved by flip1995

[bors]

⌛ Testing commit 5265ab8 with merge d71e9c4...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: flip1995
Pushing d71e9c4 to master...