1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
1| |#![feature(c_unwind)]
2| |#![allow(unused_assignments)]
3| |
4| 12|extern "C" fn might_abort(should_abort: bool) {
5| 12| if should_abort {
6| 0| println!("aborting...");
7| 0| panic!("panics and aborts");
8| 12| } else {
9| 12| println!("Don't Panic");
10| 12| }
11| 12|}
12| |
13| 1|fn main() -> Result<(), u8> {
14| 1| let mut countdown = 10;
15| 11| while countdown > 0 {
16| 10| if countdown < 5 {
17| 4| might_abort(false);
18| 6| }
19| | // See discussion (below the `Notes` section) on coverage results for the closing brace.
20| 10| if countdown < 5 { might_abort(false); } // Counts for different regions on one line.
^4 ^6
21| | // For the following example, the closing brace is the last character on the line.
22| | // This shows the character after the closing brace is highlighted, even if that next
23| | // character is a newline.
24| 10| if countdown < 5 { might_abort(false); }
^4 ^6
25| 10| countdown -= 1;
26| | }
27| 1| Ok(())
28| 1|}
29| |
30| |// Notes:
31| |// 1. Compare this program and its coverage results to those of the similar tests
32| |// `panic_unwind.rs` and `try_error_result.rs`.
33| |// 2. This test confirms the coverage generated when a program includes `TerminatorKind::Abort`.
34| |// 3. The test does not invoke the abort. By executing to a successful completion, the coverage
35| |// results show where the program did and did not execute.
36| |// 4. If the program actually aborted, the coverage counters would not be saved (which "works as
37| |// intended"). Coverage results would show no executed coverage regions.
38| |// 6. If `should_abort` is `true` and the program aborts, the program exits with a `132` status
39| |// (on Linux at least).
40| |
41| |/*
42| |
43| |Expect the following coverage results:
44| |
45| |```text
46| | 16| 11| while countdown > 0 {
47| | 17| 10| if countdown < 5 {
48| | 18| 4| might_abort(false);
49| | 19| 6| }
50| |```
51| |
52| |This is actually correct.
53| |
54| |The condition `countdown < 5` executed 10 times (10 loop iterations).
55| |
56| |It evaluated to `true` 4 times, and executed the `might_abort()` call.
57| |
58| |It skipped the body of the `might_abort()` call 6 times. If an `if` does not include an explicit
59| |`else`, the coverage implementation injects a counter, at the character immediately after the `if`s
60| |closing brace, to count the "implicit" `else`. This is the only way to capture the coverage of the
61| |non-true condition.
62| |
63| |As another example of why this is important, say the condition was `countdown < 50`, which is always
64| |`true`. In that case, we wouldn't have a test for what happens if `might_abort()` is not called.
65| |The closing brace would have a count of `0`, highlighting the missed coverage.
66| |*/
|
