rust/tests/ui/rust-2018/remove-extern-crate.rs

//@ run-rustfix
//@ edition:2018
//@ check-pass
//@ aux-build:remove-extern-crate.rs
//@ compile-flags:--extern remove_extern_crate

#![warn(rust_2018_idioms)]
#![allow(dropping_copy_types)]
#![allow(unused_imports)]

extern crate core; //~ WARNING unused extern crate
// Shouldn't suggest changing to `use`, as `another_name`
// would no longer be added to the prelude which could cause
// compilation errors for imports that use `another_name` in other
// modules. See #57672.
extern crate core as another_name;
use remove_extern_crate;
#[macro_use]
extern crate remove_extern_crate as something_else;

// Shouldn't suggest changing to `use`, as the `alloc`
// crate is not in the extern prelude - see #54381.
extern crate alloc;

fn main() {
    another_name::mem::drop(3);
    another::foo();
    with_visibility::foo();
    remove_extern_crate::foo!();
    bar!();
    alloc::vec![5];
}

mod another {
    extern crate core; //~ WARNING `extern crate` is not idiomatic
    use remove_extern_crate;

    pub fn foo() {
        core::mem::drop(4);
        remove_extern_crate::foo!();
    }
}

mod with_visibility {
    pub extern crate core; //~ WARNING `extern crate` is not idiomatic

    pub fn foo() {
        core::mem::drop(4);
        remove_extern_crate::foo!();
    }
}