LL| |#![allow(unused_assignments, dead_code)] | |
LL| | | |
LL| |// compile-flags: --edition=2018 -C opt-level=1 | |
LL| | | |
LL| 1|async fn c(x: u8) -> u8 { | |
LL| 1| if x == 8 { | |
LL| 1| 1 | |
LL| | } else { | |
LL| 0| 0 | |
LL| | } | |
LL| 1|} | |
LL| | | |
LL| 0|async fn d() -> u8 { 1 } | |
LL| | | |
LL| 0|async fn e() -> u8 { 1 } // unused function; executor does not block on `g()` | |
LL| | | |
LL| 1|async fn f() -> u8 { 1 } | |
LL| | | |
LL| 0|async fn foo() -> [bool; 10] { [false; 10] } // unused function; executor does not block on `h()` | |
LL| | | |
LL| 1|pub async fn g(x: u8) { | |
LL| 0| match x { | |
LL| 0| y if e().await == y => (), | |
LL| 0| y if f().await == y => (), | |
LL| 0| _ => (), | |
LL| | } | |
LL| 0|} | |
LL| | | |
LL| 1|async fn h(x: usize) { // The function signature is counted when called, but the body is not | |
LL| 0| // executed (not awaited) so the open brace has a `0` count (at least when | |
LL| 0| // displayed with `llvm-cov show` in color-mode). | |
LL| 0| match x { | |
LL| 0| y if foo().await[y] => (), | |
LL| 0| _ => (), | |
LL| | } | |
LL| 0|} | |
LL| | | |
LL| 1|async fn i(x: u8) { // line coverage is 1, but there are 2 regions: | |
LL| 1| // (a) the function signature, counted when the function is called; and | |
LL| 1| // (b) the open brace for the function body, counted once when the body is | |
LL| 1| // executed asynchronously. | |
LL| 1| match x { | |
LL| 1| y if c(x).await == y + 1 => { d().await; } | |
^0 ^0 ^0 ^0 | |
LL| 1| y if f().await == y + 1 => (), | |
^0 ^0 ^0 | |
LL| 1| _ => (), | |
LL| | } | |
LL| 1|} | |
LL| | | |
LL| 1|fn j(x: u8) { | |
LL| 1| // non-async versions of `c()`, `d()`, and `f()` to make it similar to async `i()`. | |
LL| 1| fn c(x: u8) -> u8 { | |
LL| 1| if x == 8 { | |
LL| 1| 1 // This line appears covered, but the 1-character expression span covering the `1` | |
^0 | |
LL| 1| // is not executed. (`llvm-cov show` displays a `^0` below the `1` ). This is because | |
LL| 1| // `fn j()` executes the open brace for the function body, followed by the function's | |
LL| 1| // first executable statement, `match x`. Inner function declarations are not | |
LL| 1| // "visible" to the MIR for `j()`, so the code region counts all lines between the | |
LL| 1| // open brace and the first statement as executed, which is, in a sense, true. | |
LL| 1| // `llvm-cov show` overcomes this kind of situation by showing the actual counts | |
LL| 1| // of the enclosed coverages, (that is, the `1` expression was not executed, and | |
LL| 1| // accurately displays a `0`). | |
LL| 1| } else { | |
LL| 1| 0 | |
LL| 1| } | |
LL| 1| } | |
LL| 1| fn d() -> u8 { 1 } // inner function is defined in-line, but the function is not executed | |
^0 | |
LL| 1| fn f() -> u8 { 1 } | |
LL| 1| match x { | |
LL| 1| y if c(x) == y + 1 => { d(); } | |
^0 ^0 | |
LL| 1| y if f() == y + 1 => (), | |
^0 ^0 | |
LL| 1| _ => (), | |
LL| | } | |
LL| 1|} | |
LL| | | |
LL| 0|fn k(x: u8) { // unused function | |
LL| 0| match x { | |
LL| 0| 1 => (), | |
LL| 0| 2 => (), | |
LL| 0| _ => (), | |
LL| | } | |
LL| 0|} | |
LL| | | |
LL| 1|fn l(x: u8) { | |
LL| 1| match x { | |
LL| 0| 1 => (), | |
LL| 0| 2 => (), | |
LL| 1| _ => (), | |
LL| | } | |
LL| 1|} | |
LL| | | |
LL| 1|async fn m(x: u8) -> u8 { x - 1 } | |
^0 | |
LL| | | |
LL| 1|fn main() { | |
LL| 1| let _ = g(10); | |
LL| 1| let _ = h(9); | |
LL| 1| let mut future = Box::pin(i(8)); | |
LL| 1| j(7); | |
LL| 1| l(6); | |
LL| 1| let _ = m(5); | |
LL| 1| executor::block_on(future.as_mut()); | |
LL| 1|} | |
LL| | | |
LL| |mod executor { | |
LL| | use core::{ | |
LL| | future::Future, | |
LL| | pin::Pin, | |
LL| | task::{Context, Poll, RawWaker, RawWakerVTable, Waker}, | |
LL| | }; | |
LL| | | |
LL| 1| pub fn block_on<F: Future>(mut future: F) -> F::Output { | |
LL| 1| let mut future = unsafe { Pin::new_unchecked(&mut future) }; | |
LL| 1| use std::hint::unreachable_unchecked; | |
LL| 1| static VTABLE: RawWakerVTable = RawWakerVTable::new( | |
LL| 1| |_| unsafe { unreachable_unchecked() }, // clone | |
^0 | |
LL| 1| |_| unsafe { unreachable_unchecked() }, // wake | |
^0 | |
LL| 1| |_| unsafe { unreachable_unchecked() }, // wake_by_ref | |
^0 | |
LL| 1| |_| (), | |
LL| 1| ); | |
LL| 1| let waker = unsafe { Waker::from_raw(RawWaker::new(core::ptr::null(), &VTABLE)) }; | |
LL| 1| let mut context = Context::from_waker(&waker); | |
LL| | | |
LL| | loop { | |
LL| 1| if let Poll::Ready(val) = future.as_mut().poll(&mut context) { | |
LL| 1| break val; | |
LL| 0| } | |
LL| | } | |
LL| 1| } | |
LL| |} | |