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Diffstat (limited to '')
-rw-r--r-- | tests/coverage-map/status-quo/abort.rs | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/tests/coverage-map/status-quo/abort.rs b/tests/coverage-map/status-quo/abort.rs new file mode 100644 index 000000000..98264bdc1 --- /dev/null +++ b/tests/coverage-map/status-quo/abort.rs @@ -0,0 +1,66 @@ +#![feature(c_unwind)] +#![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"); + } +} + +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. +*/ |