src/test/mir-opt/issue-41110.rs

// ignore-wasm32-bare compiled with panic=abort by default

// check that we don't emit multiple drop flags when they are not needed.

fn main() {
    let x = S.other(S.id());
}

// no_mangle to make sure this gets instantiated even in an executable.
#[no_mangle]
pub fn test() {
    let u = S;
    let mut v = S;
    drop(v);
    v = u;
}

struct S;
impl Drop for S {
    fn drop(&mut self) {
    }
}

impl S {
    fn id(self) -> Self { self }
    fn other(self, s: Self) {}
}

// END RUST SOURCE
// START rustc.main.ElaborateDrops.after.mir
//    let mut _0: ();
//    let _1: ();
//    let mut _2: S;
//    let mut _3: S;
//    let mut _4: S;
//    let mut _5: bool;
//    scope 1 {
//        debug x => _1;
//    }
//    ...
//    bb0: {
// END rustc.main.ElaborateDrops.after.mir
// START rustc.test.ElaborateDrops.after.mir
//    let mut _0: ();
//    let _1: S;
//    let _3: ();
//    let mut _4: S;
//    let mut _5: S;
//    let mut _6: bool;
//    ...
//    debug u => _1;
//    ...
//    let mut _2: S;
//    ...
//    debug v => _2;
//    ...
//    bb0: {
// END rustc.test.ElaborateDrops.after.mir