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|
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| |}
|
