And introduce two new directives for ui tests:
* `run-crash`
* `run-fail-or-crash`
Normally a `run-fail` ui test like tests that panic shall not be
terminated by a signal like `SIGABRT`. So begin having that as a hard
requirement.
Some of our current tests do terminate by a signal/crash however.
Introduce and use `run-crash` for those tests. Note that Windows crashes
are not handled by signals but by certain high bits set on the process
exit code. Example exit code for crash on Windows: `0xc000001d`.
Because of this, we define "crash" on all platforms as "not exit with
success and not exit with a regular failure code in the range 1..=127".
Some tests behave differently on different targets:
* Targets without unwind support will abort (crash) instead of exit with
failure code 101 after panicking. As a special case, allow crashes for
`run-fail` tests for such targets.
* Different sanitizer implementations handle detected memory problems
differently. Some abort (crash) the process while others exit with
failure code 1. Introduce and use `run-fail-or-crash` for such tests.
Invert the order that we pass the arguments to the
`contract_check_ensures` function to avoid the warning when the tail
of the function is unreachable.
Note that the call itself is also unreachable, but we have already
handled that case by ignoring unreachable call for contract calls.
Use `const_eval_select!()` macro to enable contract checking only at
runtime. The existing contract logic relies on closures,
which are not supported in constant functions.
This commit also removes one level of indirection for ensures clauses,
however, it currently has a spurious warning message when the bottom
of the function is unreachable.
This has now been approved as a language feature and no longer needs
a `rustc_` prefix.
Also change the `contracts` feature to be marked as incomplete and
`contracts_internals` as internal.
1. Document the new intrinsics.
2. Make the intrinsics actually check the contract if enabled, and
remove `contract::check_requires` function.
3. Use panic with no unwind in case contract is using to check for
safety, we probably don't want to unwind. Following the same
reasoning as UB checks.
The extended syntax for function signature that includes contract clauses
should never be user exposed versus the interface we want to ship
externally eventually.
