rust/tests/ui/thread_local_initializer_can_be_made_const.fixed
Quinn Sinclair 206b1a1ac9 Threadlocal_initializer_can_be_made_const will not trigger for unreachable initializers
This commit introduces a check to ensure that the lint won't trigger when the initializer is
unreachable, such as:

```
thread_local! {
    static STATE: Cell<usize> = panic!();
}
```

This is achieved by looking at the unpeeled initializer expression and ensuring that the parent
macro is not `panic!()`, `todo!()`, `unreachable!()`, `unimplemented!()`.

fixes #12637

changelog: [`threadlocal_initializer_can_be_made_const`] will no longer trigger on `unreachable` macros.
2024-04-19 23:21:33 +02:00

76 lines
2.4 KiB
Rust

#![warn(clippy::thread_local_initializer_can_be_made_const)]
use std::cell::{Cell, RefCell};
fn main() {
// lint and suggest const
thread_local! {
static BUF_1: RefCell<String> = const { 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 = const { 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> = const { RefCell::new(String::new()) };
static CONST_MIXED_WITH:i32 = const { 1 };
static BUF_4_CAN_BE_MADE_CONST: RefCell<String> = const { 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 = const { 1 };
//~^ ERROR: initializer for `thread_local` value can be made `const`
static PEEL_ME_MANY: i32 = const { { 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;
}
}