From a34c92760c4ced5eff6ac9a3d8cabab1ec200b0d Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Wed, 22 Mar 2023 17:13:00 +0000
Subject: [PATCH 1/2] Implement non-const Destruct trait in new solver

---
 .../rustc_trait_selection/src/solve/assembly.rs    |  7 +++++++
 .../src/solve/project_goals.rs                     |  7 +++++++
 .../rustc_trait_selection/src/solve/trait_goals.rs | 14 ++++++++++++++
 tests/ui/traits/new-solver/destruct.rs             | 13 +++++++++++++
 4 files changed, 41 insertions(+)
 create mode 100644 tests/ui/traits/new-solver/destruct.rs

diff --git a/compiler/rustc_trait_selection/src/solve/assembly.rs b/compiler/rustc_trait_selection/src/solve/assembly.rs
index 76cde1a6692..f9cb56655ae 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly.rs
@@ -209,6 +209,11 @@ fn consider_builtin_discriminant_kind_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
+
+    fn consider_builtin_destruct_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
@@ -336,6 +341,8 @@ fn assemble_builtin_impl_candidates<G: GoalKind<'tcx>>(
             G::consider_builtin_unsize_candidate(self, goal)
         } else if lang_items.discriminant_kind_trait() == Some(trait_def_id) {
             G::consider_builtin_discriminant_kind_candidate(self, goal)
+        } else if lang_items.destruct_trait() == Some(trait_def_id) {
+            G::consider_builtin_destruct_candidate(self, goal)
         } else {
             Err(NoSolution)
         };
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index 93d77c39f95..df821a2913a 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -483,6 +483,13 @@ fn consider_builtin_discriminant_kind_candidate(
             ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
         })
     }
+
+    fn consider_builtin_destruct_candidate(
+        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        bug!("`Destruct` does not have an associated type: {:?}", goal);
+    }
 }
 
 /// This behavior is also implemented in `rustc_ty_utils` and in the old `project` code.
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 8ab55c79fc4..29b7ab61c7c 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -513,6 +513,20 @@ fn consider_builtin_discriminant_kind_candidate(
         // `DiscriminantKind` is automatically implemented for every type.
         ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
     }
+
+    fn consider_builtin_destruct_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        if !goal.param_env.is_const() {
+            // `Destruct` is automatically implemented for every type in
+            // non-const environments.
+            ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+        } else {
+            // FIXME(-Ztrait-solver=next): Implement this when we get const working in the new solver
+            Err(NoSolution)
+        }
+    }
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
diff --git a/tests/ui/traits/new-solver/destruct.rs b/tests/ui/traits/new-solver/destruct.rs
new file mode 100644
index 00000000000..30d7777b78a
--- /dev/null
+++ b/tests/ui/traits/new-solver/destruct.rs
@@ -0,0 +1,13 @@
+// compile-flags: -Ztrait-solver=next
+// check-pass
+
+#![feature(const_trait_impl)]
+
+fn foo(_: impl std::marker::Destruct) {}
+
+struct MyAdt;
+
+fn main() {
+    foo(1);
+    foo(MyAdt);
+}

From 8390c61690186ddc45f97684732c8d3b6458cc44 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Wed, 22 Mar 2023 18:26:33 +0000
Subject: [PATCH 2/2] Drive-by: Add -Ztrait-solver=next to canonical int var
 test

---
 tests/ui/traits/new-solver/canonical-int-var-eq-in-response.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/ui/traits/new-solver/canonical-int-var-eq-in-response.rs b/tests/ui/traits/new-solver/canonical-int-var-eq-in-response.rs
index 3f7316a2279..4b013983a4a 100644
--- a/tests/ui/traits/new-solver/canonical-int-var-eq-in-response.rs
+++ b/tests/ui/traits/new-solver/canonical-int-var-eq-in-response.rs
@@ -1,3 +1,4 @@
+// compile-flags: -Ztrait-solver=next
 // check-pass
 
 trait Mirror {