mirror of https://github.com/rust-lang/rust
39 lines
1.6 KiB
Plaintext
39 lines
1.6 KiB
Plaintext
LL| |#![feature(core_intrinsics)]
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LL| |#![feature(coverage_attribute)]
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LL| |//@ edition: 2021
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LL| |
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LL| |// <https://github.com/rust-lang/rust/issues/116171>
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LL| |// If we instrument a function for coverage, but all of its counter-increment
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LL| |// statements are removed by MIR optimizations, LLVM will think it isn't
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LL| |// instrumented and it will disappear from coverage maps and coverage reports.
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LL| |// Most MIR opts won't cause this because they tend not to remove statements
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LL| |// from bb0, but `UnreachablePropagation` can do so if it sees that bb0 ends
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LL| |// with `TerminatorKind::Unreachable`.
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LL| |
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LL| |use std::hint::{black_box, unreachable_unchecked};
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LL| |
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LL| 0|static UNREACHABLE_CLOSURE: fn() = || unsafe { unreachable_unchecked() };
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LL| |
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LL| 0|fn unreachable_function() {
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LL| 0| unsafe { unreachable_unchecked() }
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LL| |}
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LL| |
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LL| |// Use an intrinsic to more reliably trigger unreachable-propagation.
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LL| 0|fn unreachable_intrinsic() {
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LL| 0| unsafe { std::intrinsics::unreachable() }
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LL| |}
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LL| |
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LL| |#[coverage(off)]
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LL| |fn main() {
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LL| | if black_box(false) {
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LL| | UNREACHABLE_CLOSURE();
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LL| | }
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LL| | if black_box(false) {
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LL| | unreachable_function();
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LL| | }
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LL| | if black_box(false) {
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LL| | unreachable_intrinsic();
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LL| | }
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LL| |}
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