53 lines
1.3 KiB
Rust
53 lines
1.3 KiB
Rust
// Test that dead code warnings are issued for superfluous assignments of
|
|
// fields or variables to themselves (issue #75356).
|
|
|
|
//@ ignore-test FIXME(81658, 83171)
|
|
|
|
//@ check-pass
|
|
#![allow(unused_assignments)]
|
|
#![warn(dead_code)]
|
|
|
|
fn main() {
|
|
let mut x = 0;
|
|
x = x;
|
|
//~^ WARNING: useless assignment of variable of type `i32` to itself
|
|
|
|
x = (x);
|
|
//~^ WARNING: useless assignment of variable of type `i32` to itself
|
|
|
|
x = {x};
|
|
// block expressions don't count as self-assignments
|
|
|
|
|
|
struct S<'a> { f: &'a str }
|
|
let mut s = S { f: "abc" };
|
|
s = s;
|
|
//~^ WARNING: useless assignment of variable of type `S` to itself
|
|
|
|
s.f = s.f;
|
|
//~^ WARNING: useless assignment of field of type `&str` to itself
|
|
|
|
|
|
struct N0 { x: Box<i32> }
|
|
struct N1 { n: N0 }
|
|
struct N2(N1);
|
|
struct N3 { n: N2 };
|
|
let mut n3 = N3 { n: N2(N1 { n: N0 { x: Box::new(42) } }) };
|
|
n3.n.0.n.x = n3.n.0.n.x;
|
|
//~^ WARNING: useless assignment of field of type `Box<i32>` to itself
|
|
|
|
let mut t = (1, ((2, 3, (4, 5)),));
|
|
t.1.0.2.1 = t.1.0.2.1;
|
|
//~^ WARNING: useless assignment of field of type `i32` to itself
|
|
|
|
|
|
let mut y = 0;
|
|
macro_rules! assign_to_y {
|
|
($cur:expr) => {{
|
|
y = $cur;
|
|
}};
|
|
}
|
|
assign_to_y!(y);
|
|
// self-assignments in macro expansions are not reported either
|
|
}
|