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Diffstat (limited to 'tests/coverage-map/status-quo/overflow.rs')
-rw-r--r-- | tests/coverage-map/status-quo/overflow.rs | 63 |
1 files changed, 0 insertions, 63 deletions
diff --git a/tests/coverage-map/status-quo/overflow.rs b/tests/coverage-map/status-quo/overflow.rs deleted file mode 100644 index bbb65c1b3..000000000 --- a/tests/coverage-map/status-quo/overflow.rs +++ /dev/null @@ -1,63 +0,0 @@ -#![allow(unused_assignments)] -// failure-status: 101 - -fn might_overflow(to_add: u32) -> u32 { - if to_add > 5 { - println!("this will probably overflow"); - } - let add_to = u32::MAX - 5; - println!("does {} + {} overflow?", add_to, to_add); - let result = to_add + add_to; - println!("continuing after overflow check"); - result -} - -fn main() -> Result<(), u8> { - let mut countdown = 10; - while countdown > 0 { - if countdown == 1 { - let result = might_overflow(10); - println!("Result: {}", result); - } else if countdown < 5 { - let result = might_overflow(1); - println!("Result: {}", result); - } - countdown -= 1; - } - Ok(()) -} - -// Notes: -// 1. Compare this program and its coverage results to those of the very similar test `assert.rs`, -// and similar tests `panic_unwind.rs`, abort.rs` and `try_error_result.rs`. -// 2. This test confirms the coverage generated when a program passes or fails a -// compiler-generated `TerminatorKind::Assert` (based on an overflow check, in this case). -// 3. Similar to how the coverage instrumentation handles `TerminatorKind::Call`, -// compiler-generated assertion failures are assumed to be a symptom of a program bug, not -// expected behavior. To simplify the coverage graphs and keep instrumented programs as -// small and fast as possible, `Assert` terminators are assumed to always succeed, and -// therefore are considered "non-branching" terminators. So, an `Assert` terminator does not -// get its own coverage counter. -// 4. After an unhandled panic or failed Assert, coverage results may not always be intuitive. -// In this test, the final count for the statements after the `if` block in `might_overflow()` -// is 4, even though the lines after `to_add + add_to` were executed only 3 times. Depending -// on the MIR graph and the structure of the code, this count could have been 3 (which might -// have been valid for the overflowed add `+`, but should have been 4 for the lines before -// the overflow. The reason for this potential uncertainty is, a `CounterKind` is incremented -// via StatementKind::Counter at the end of the block, but (as in the case in this test), -// a CounterKind::Expression is always evaluated. In this case, the expression was based on -// a `Counter` incremented as part of the evaluation of the `if` expression, which was -// executed, and counted, 4 times, before reaching the overflow add. - -// If the program did not overflow, the coverage for `might_overflow()` would look like this: -// -// 4| |fn might_overflow(to_add: u32) -> u32 { -// 5| 4| if to_add > 5 { -// 6| 0| println!("this will probably overflow"); -// 7| 4| } -// 8| 4| let add_to = u32::MAX - 5; -// 9| 4| println!("does {} + {} overflow?", add_to, to_add); -// 10| 4| let result = to_add + add_to; -// 11| 4| println!("continuing after overflow check"); -// 12| 4| result -// 13| 4|} |