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.

3 files changed, 16 insertions, 1 deletions

diff --git a/compiler/rustc_const_eval/src/check_consts/check.rs b/compiler/rustc_const_eval/src/check_consts/check.rs
index e8052a3c83a..d0ce027ec2b 100644
--- a/compiler/rustc_const_eval/src/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/check_consts/check.rs
@@ -675,7 +675,11 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             Rvalue::Cast(_, _, _) => {}
 
             Rvalue::NullaryOp(
-                NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(_) | NullOp::UbChecks,
+                NullOp::SizeOf
+                | NullOp::AlignOf
+                | NullOp::OffsetOf(_)
+                | NullOp::UbChecks
+                | NullOp::ContractChecks,
                 _,
             ) => {}
             Rvalue::ShallowInitBox(_, _) => {}
diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs
index 8f6b15b8df0..1a799f5dea5 100644
--- a/compiler/rustc_const_eval/src/interpret/machine.rs
+++ b/compiler/rustc_const_eval/src/interpret/machine.rs
@@ -293,6 +293,9 @@ pub trait Machine<'tcx>: Sized {
     /// Determines the result of a `NullaryOp::UbChecks` invocation.
     fn ub_checks(_ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool>;
 
+    /// Determines the result of a `NullaryOp::ContractChecks` invocation.
+    fn contract_checks(_ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool>;
+
     /// Called when the interpreter encounters a `StatementKind::ConstEvalCounter` instruction.
     /// You can use this to detect long or endlessly running programs.
     #[inline]
@@ -680,6 +683,13 @@ pub macro compile_time_machine(<$tcx: lifetime>) {
     }
 
     #[inline(always)]
+    fn contract_checks(_ecx: &InterpCx<$tcx, Self>) -> InterpResult<$tcx, bool> {
+        // We can't look at `tcx.sess` here as that can differ across crates, which can lead to
+        // unsound differences in evaluating the same constant at different instantiation sites.
+        interp_ok(true)
+    }
+
+    #[inline(always)]
     fn adjust_global_allocation<'b>(
         _ecx: &InterpCx<$tcx, Self>,
         _id: AllocId,
diff --git a/compiler/rustc_const_eval/src/interpret/operator.rs b/compiler/rustc_const_eval/src/interpret/operator.rs
index 5fa632fc57a..899670aeb62 100644
--- a/compiler/rustc_const_eval/src/interpret/operator.rs
+++ b/compiler/rustc_const_eval/src/interpret/operator.rs
@@ -537,6 +537,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 ImmTy::from_uint(val, usize_layout())
             }
             UbChecks => ImmTy::from_bool(M::ub_checks(self)?, *self.tcx),
+            ContractChecks => ImmTy::from_bool(M::contract_checks(self)?, *self.tcx),
         })
     }
 }