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