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Diffstat (limited to '')
| -rw-r--r-- | tests/coverage/unreachable.coverage | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/tests/coverage/unreachable.coverage b/tests/coverage/unreachable.coverage new file mode 100644 index 000000000..fa0ac9ccf --- /dev/null +++ b/tests/coverage/unreachable.coverage @@ -0,0 +1,38 @@ + 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| |} + |