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.

5 files changed, 18 insertions, 1 deletions

diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs
index c261e25100d..d2ffd26f0a0 100644
--- a/compiler/rustc_mir_transform/src/gvn.rs
+++ b/compiler/rustc_mir_transform/src/gvn.rs
@@ -545,6 +545,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                         .offset_of_subfield(self.typing_env(), layout, fields.iter())
                         .bytes(),
                     NullOp::UbChecks => return None,
+                    NullOp::ContractChecks => return None,
                 };
                 let usize_layout = self.ecx.layout_of(self.tcx.types.usize).unwrap();
                 let imm = ImmTy::from_uint(val, usize_layout);
diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs
index 2864cc0b9fe..e43254ba089 100644
--- a/compiler/rustc_mir_transform/src/known_panics_lint.rs
+++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs
@@ -629,6 +629,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
                         .offset_of_subfield(self.typing_env, op_layout, fields.iter())
                         .bytes(),
                     NullOp::UbChecks => return None,
+                    NullOp::ContractChecks => return None,
                 };
                 ImmTy::from_scalar(Scalar::from_target_usize(val, self), layout).into()
             }
diff --git a/compiler/rustc_mir_transform/src/lower_intrinsics.rs b/compiler/rustc_mir_transform/src/lower_intrinsics.rs
index 9a9f66ed4fd..9c21bcfc0d2 100644
--- a/compiler/rustc_mir_transform/src/lower_intrinsics.rs
+++ b/compiler/rustc_mir_transform/src/lower_intrinsics.rs
@@ -34,6 +34,17 @@ impl<'tcx> crate::MirPass<'tcx> for LowerIntrinsics {
                         });
                         terminator.kind = TerminatorKind::Goto { target };
                     }
+                    sym::contract_checks => {
+                        let target = target.unwrap();
+                        block.statements.push(Statement {
+                            source_info: terminator.source_info,
+                            kind: StatementKind::Assign(Box::new((
+                                *destination,
+                                Rvalue::NullaryOp(NullOp::ContractChecks, tcx.types.bool),
+                            ))),
+                        });
+                        terminator.kind = TerminatorKind::Goto { target };
+                    }
                     sym::forget => {
                         let target = target.unwrap();
                         block.statements.push(Statement {
diff --git a/compiler/rustc_mir_transform/src/promote_consts.rs b/compiler/rustc_mir_transform/src/promote_consts.rs
index 9101c9bfc9a..4dbbcae1756 100644
--- a/compiler/rustc_mir_transform/src/promote_consts.rs
+++ b/compiler/rustc_mir_transform/src/promote_consts.rs
@@ -457,6 +457,7 @@ impl<'tcx> Validator<'_, 'tcx> {
                 NullOp::AlignOf => {}
                 NullOp::OffsetOf(_) => {}
                 NullOp::UbChecks => {}
+                NullOp::ContractChecks => {}
             },
 
             Rvalue::ShallowInitBox(_, _) => return Err(Unpromotable),
diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs
index e282eaf761c..b7a3770fc6b 100644
--- a/compiler/rustc_mir_transform/src/validate.rs
+++ b/compiler/rustc_mir_transform/src/validate.rs
@@ -1379,7 +1379,10 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             Rvalue::Repeat(_, _)
             | Rvalue::ThreadLocalRef(_)
             | Rvalue::RawPtr(_, _)
-            | Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::UbChecks, _)
+            | Rvalue::NullaryOp(
+                NullOp::SizeOf | NullOp::AlignOf | NullOp::UbChecks | NullOp::ContractChecks,
+                _,
+            )
             | Rvalue::Discriminant(_) => {}
 
             Rvalue::WrapUnsafeBinder(op, ty) => {