missing_const_for_thread_local.rs

#![warn(clippy::missing_const_for_thread_local)]

use std::cell::{Cell, RefCell};

fn main() {
    // lint and suggest const
    thread_local! {
        static BUF_1: RefCell<String> = RefCell::new(String::new());
    }
    //~^^ ERROR: initializer for `thread_local` value can be made `const`

    // don't lint
    thread_local! {
        static BUF_2: RefCell<String> = const { RefCell::new(String::new()) };
    }

    thread_local! {
        static SIMPLE:i32 = 1;
    }
    //~^^ ERROR: initializer for `thread_local` value can be made `const`

    // lint and suggest const for all non const items
    thread_local! {
        static BUF_3_CAN_BE_MADE_CONST: RefCell<String> = RefCell::new(String::new());
        static CONST_MIXED_WITH:i32 = const { 1 };
        static BUF_4_CAN_BE_MADE_CONST: RefCell<String> = RefCell::new(String::new());
    }
    //~^^^^ ERROR: initializer for `thread_local` value can be made `const`
    //~^^^ ERROR: initializer for `thread_local` value can be made `const`

    thread_local! {
        static PEEL_ME: i32 = { 1 };
        //~^ ERROR: initializer for `thread_local` value can be made `const`
        static PEEL_ME_MANY: i32 = { let x = 1; x * x };
        //~^ ERROR: initializer for `thread_local` value can be made `const`
    }
}

fn issue_12637() {
    /// The set methods on LocalKey<Cell<T>> and LocalKey<RefCell<T>> are
    /// guaranteed to bypass the thread_local's initialization expression.
    /// See rust-lang/rust#92122. Thus, = panic!() is a useful idiom for
    /// forcing the use of set on each thread before it accesses the thread local in any other
    /// manner.
    thread_local! {
        static STATE_12637_PANIC: Cell<usize> = panic!();
    }
    STATE_12637_PANIC.set(9);
    println!("{}", STATE_12637_PANIC.get());

    thread_local! {
        static STATE_12637_TODO: Cell<usize> = todo!();
    }
    STATE_12637_TODO.set(9);
    println!("{}", STATE_12637_TODO.get());

    thread_local! {
        static STATE_12637_UNIMPLEMENTED: Cell<usize> = unimplemented!();
    }
    STATE_12637_UNIMPLEMENTED.set(9);
    println!("{}", STATE_12637_UNIMPLEMENTED.get());

    thread_local! {
        static STATE_12637_UNREACHABLE: Cell<usize> = unreachable!();
    }
    STATE_12637_UNREACHABLE.set(9);
    println!("{}", STATE_12637_UNREACHABLE.get());
}

#[clippy::msrv = "1.58"]
fn f() {
    thread_local! {
        static TLS: i32 = 1;
    }
}