Contracts core intrinsics.

These are hooks to:

  1. control whether contract checks are run
  2. allow 3rd party tools to intercept and reintepret the results of running contracts.

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/ui/contracts/contract-intrinsics.rs b/tests/ui/contracts/contract-intrinsics.rs
new file mode 100644
index 00000000000..6e3565baf7a
--- /dev/null
+++ b/tests/ui/contracts/contract-intrinsics.rs
@@ -0,0 +1,23 @@
+//@ run-pass
+//@ revisions: yes no none
+//@ [yes] compile-flags: -Zcontract-checks=yes
+//@ [no] compile-flags: -Zcontract-checks=no
+#![feature(cfg_contract_checks, rustc_contracts, core_intrinsics)]
+
+fn main() {
+    #[cfg(none)] // default: disabled
+    assert_eq!(core::intrinsics::contract_checks(), false);
+
+    #[cfg(yes)] // explicitly enabled
+    assert_eq!(core::intrinsics::contract_checks(), true);
+
+    #[cfg(no)] // explicitly disabled
+    assert_eq!(core::intrinsics::contract_checks(), false);
+
+    assert_eq!(core::intrinsics::contract_check_requires(|| true), true);
+    assert_eq!(core::intrinsics::contract_check_requires(|| false), false);
+
+    let doubles_to_two = { let old = 2; move |ret| ret + ret == old };
+    assert_eq!(core::intrinsics::contract_check_ensures(&1, doubles_to_two), true);
+    assert_eq!(core::intrinsics::contract_check_ensures(&2, doubles_to_two), false);
+}