mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-30 02:33:55 +00:00
67 lines
2.5 KiB
Rust
67 lines
2.5 KiB
Rust
#![allow(unused_assignments)]
|
|
|
|
extern "C" fn might_abort(should_abort: bool) {
|
|
if should_abort {
|
|
println!("aborting...");
|
|
panic!("panics and aborts");
|
|
} else {
|
|
println!("Don't Panic");
|
|
}
|
|
}
|
|
|
|
#[rustfmt::skip]
|
|
fn main() -> Result<(), u8> {
|
|
let mut countdown = 10;
|
|
while countdown > 0 {
|
|
if countdown < 5 {
|
|
might_abort(false);
|
|
}
|
|
// See discussion (below the `Notes` section) on coverage results for the closing brace.
|
|
if countdown < 5 { might_abort(false); } // Counts for different regions on one line.
|
|
// For the following example, the closing brace is the last character on the line.
|
|
// This shows the character after the closing brace is highlighted, even if that next
|
|
// character is a newline.
|
|
if countdown < 5 { might_abort(false); }
|
|
countdown -= 1;
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
// Notes:
|
|
// 1. Compare this program and its coverage results to those of the similar tests
|
|
// `panic_unwind.rs` and `try_error_result.rs`.
|
|
// 2. This test confirms the coverage generated when a program includes `UnwindAction::Terminate`.
|
|
// 3. The test does not invoke the abort. By executing to a successful completion, the coverage
|
|
// results show where the program did and did not execute.
|
|
// 4. If the program actually aborted, the coverage counters would not be saved (which "works as
|
|
// intended"). Coverage results would show no executed coverage regions.
|
|
// 6. If `should_abort` is `true` and the program aborts, the program exits with a `132` status
|
|
// (on Linux at least).
|
|
|
|
/*
|
|
|
|
Expect the following coverage results:
|
|
|
|
```text
|
|
16| 11| while countdown > 0 {
|
|
17| 10| if countdown < 5 {
|
|
18| 4| might_abort(false);
|
|
19| 6| }
|
|
```
|
|
|
|
This is actually correct.
|
|
|
|
The condition `countdown < 5` executed 10 times (10 loop iterations).
|
|
|
|
It evaluated to `true` 4 times, and executed the `might_abort()` call.
|
|
|
|
It skipped the body of the `might_abort()` call 6 times. If an `if` does not include an explicit
|
|
`else`, the coverage implementation injects a counter, at the character immediately after the `if`s
|
|
closing brace, to count the "implicit" `else`. This is the only way to capture the coverage of the
|
|
non-true condition.
|
|
|
|
As another example of why this is important, say the condition was `countdown < 50`, which is always
|
|
`true`. In that case, we wouldn't have a test for what happens if `might_abort()` is not called.
|
|
The closing brace would have a count of `0`, highlighting the missed coverage.
|
|
*/
|