Rethink should_panic and fail_uncoverable options as global condi…

…tions (model-checking#2967)

This PR is the next step to rework/introduce the
`should_panic`/`fail_uncoverable` options as global conditions.

Until now, we haven't had a concrete proposal to do so other than the
implementation in model-checking#2532. This PR presents one for each option in their
respective RFCs. I'd like to agree on this design before starting the
code review for model-checking#2532.

Related to model-checking#1905 model-checking#2272 model-checking#2299 model-checking#2516

rfc/src/rfcs/0003-cover-statement.md

@@ -2,7 +2,7 @@
 - **Feature Request Issue:** <https://github.com/model-checking/kani/issues/696>
 - **RFC PR:** <https://github.com/model-checking/kani/pull/1906>
 - **Status:** Unstable
-- **Version:** 0
+- **Version:** 1
 
 -------------------
 
@@ -85,7 +85,16 @@ fn foo() {
 }
 ```
 
-We can consider adding an option that would cause verification to fail if a cover property was unsatisfiable or unreachable, e.g. `--fail-uncoverable`.
+The `--fail-uncoverable` option will allow users to fail the verification if a cover property is unsatisfiable or unreachable.
+This option will be integrated within the framework of [Global Conditions](https://model-checking.github.io/kani/rfc/rfcs/0007-global-conditions.html), which is used to define properties that depend on other properties.
+
+Using the `--fail-uncoverable` option will enable the global condition with name `fail_uncoverable`.
+Following the format for global conditions, the outcome will be one of the following:
+ 1. `` - fail_uncoverable: FAILURE (expected all cover statements to be satisfied, but at least one was not)``
+ 2. `` - fail_uncoverable: SUCCESS (all cover statements were satisfied as expected)``
+
+Note that the criteria to achieve a `SUCCESS` status depends on all properties of the `"cover"` class having a `SATISFIED` status.
+Otherwise, we return a `FAILURE` status.
 
 ### Inclusion in the Verification Summary
 

rfc/src/rfcs/0005-should-panic-attr.md

@@ -2,8 +2,10 @@
 - **Feature Request Issue:** <https://github.com/model-checking/kani/issues/600>
 - **RFC PR:** <https://github.com/model-checking/kani/pull/2272>
 - **Status:** Unstable
-- **Version:** 0
-- **Proof-of-concept:** <https://github.com/model-checking/kani/pull/2315>
+- **Version:** 1
+- **Proof-of-concept:**
+ * Version 0: <https://github.com/model-checking/kani/pull/2315>
+ * Version 1: <https://github.com/model-checking/kani/pull/2532>
 
 -------------------
 
@@ -95,20 +97,23 @@ Note that it's important that we provide the user with this feedback:
  2. **(Outcome)**: What's the actual result that Kani produced after the analysis?
 This will avoid a potential scenario where the user doesn't know for sure if the attribute has had an effect when verifying the harness.
 
+Therefore, the representation must make clear both the expectation and the outcome.
 Below, we show how we'll represent this result.
 
-#### Recommended Representation: Changes to overall result
 
-The representation must make clear both the expectation and the outcome.
-Moreover, the overall result must change according to the verification results (i.e., the failures that were found).
+#### Recommended Representation: As a Global Condition
 
-Using the `#[kani::should_panic]` attribute will return one of the following results:
- 1. `VERIFICATION:- FAILED (encountered no panics, but at least one was expected)` if there were no failures.
- 2. `VERIFICATION:- FAILED (encountered failures other than panics, which were unexpected)` if there were failures but not all them had `prop.property_class() == "assertion"`.
- 3. `VERIFICATION:- SUCCESSFUL (encountered one or more panics as expected)` otherwise.
+The `#[kani::should_panic]` attribute essentially behaves as a property that depends on other properties.
+This makes it well-suited for integration within the framework of [Global Conditions](https://model-checking.github.io/kani/rfc/rfcs/0007-global-conditions.html).
 
-Note that the criteria to achieve a `SUCCESSFUL` result depends on all failures having the property class `"assertion"`.
-If they don't, then the failed properties may contain UB, so we return a `FAILED` result instead.
+Using the `#[kani::should_panic]` attribute will enable the global condition with name `should_panic`.
+Following the format for global conditions, the outcome will be one of the following:
+ 1. `` - `should_panic`: FAILURE (encountered no panics, but at least one was expected)`` if there were no failures.
+ 2. `` - `should_panic`: FAILURE (encountered failures other than panics, which were unexpected)`` if there were failures but not all them had `prop.property_class() == "assertion"`.
+ 3. `` - `should_panic`: SUCCESS (encountered one or more panics as expected)`` otherwise.
+
+Note that the criteria to achieve a `SUCCESS` status depends on all failed properties having the property class `"assertion"`.
+If they don't, then the failed properties may contain UB, so we return a `FAILURE` status instead.
 
 ### Multiple Harnesses