blob: fa0ac9ccfa1c80b3237dcd2b7aba9be520e0ac10 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
LL| |#![feature(core_intrinsics)]
LL| |#![feature(coverage_attribute)]
LL| |// compile-flags: --edition=2021
LL| |
LL| |// <https://github.com/rust-lang/rust/issues/116171>
LL| |// If we instrument a function for coverage, but all of its counter-increment
LL| |// statements are removed by MIR optimizations, LLVM will think it isn't
LL| |// instrumented and it will disappear from coverage maps and coverage reports.
LL| |// Most MIR opts won't cause this because they tend not to remove statements
LL| |// from bb0, but `UnreachablePropagation` can do so if it sees that bb0 ends
LL| |// with `TerminatorKind::Unreachable`.
LL| |
LL| |use std::hint::{black_box, unreachable_unchecked};
LL| |
LL| 0|static UNREACHABLE_CLOSURE: fn() = || unsafe { unreachable_unchecked() };
LL| |
LL| 0|fn unreachable_function() {
LL| 0| unsafe { unreachable_unchecked() }
LL| 0|}
LL| |
LL| |// Use an intrinsic to more reliably trigger unreachable-propagation.
LL| 0|fn unreachable_intrinsic() {
LL| 0| unsafe { std::intrinsics::unreachable() }
LL| 0|}
LL| |
LL| |#[coverage(off)]
LL| |fn main() {
LL| | if black_box(false) {
LL| | UNREACHABLE_CLOSURE();
LL| | }
LL| | if black_box(false) {
LL| | unreachable_function();
LL| | }
LL| | if black_box(false) {
LL| | unreachable_intrinsic();
LL| | }
LL| |}
|
