WIP2: compute_unstable_feature_goal

Author: tiif

compiler/rustc_middle/src/ty/context.rs

@@ -814,6 +814,10 @@ impl<'tcx> rustc_type_ir::inherent::Features<TyCtxt<'tcx>> for &'tcx rustc_featu
     fn associated_const_equality(self) -> bool {
         self.associated_const_equality()
     }
+
+    fn impl_stability(self) -> bool {
+        self.impl_stability()
+    }
 }
 
 impl<'tcx> rustc_type_ir::inherent::Span<TyCtxt<'tcx>> for Span {

compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs

@@ -529,7 +529,7 @@ where
                     self.compute_const_arg_has_type_goal(Goal { param_env, predicate: (ct, ty) })
                 }
                 ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(symbol)) => {
-                    self.compute_unstable_feature_goal(Goal {param_env, predicate}, symbol)
+                    self.compute_unstable_feature_goal(param_env, symbol)
                 },
                 ty::PredicateKind::Subtype(predicate) => {
                     self.compute_subtype_goal(Goal { param_env, predicate })

compiler/rustc_next_trait_solver/src/solve/mod.rs

@@ -147,26 +147,25 @@ where
         }
     }
 
-    fn compute_unstable_feature_goal(&mut self, goal: Goal<I, I::Term>, symbol: Symbol) -> QueryResult<I> {
+    fn compute_unstable_feature_goal(&mut self, param_env: <I as Interner>::ParamEnv, symbol: <I as Interner>::Symbol) -> QueryResult<I> {
         // Iterate through all goals in param_env to find the one that has the same 
         // symbol as the one in the goal
-        for pred in goal.param_env.caller_bounds() {
+        for pred in param_env.caller_bounds().iter() {
             match pred.kind().skip_binder() {
                 ty::ClauseKind::UnstableFeature(sym) => {
                     if sym == symbol {
-                        self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+                        return self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes);
                     }
                 }
                 _ => {} // don't care
             }
         }
 
-
-        // TODO: If stability attrs feature is enabled
-        //if self.origin_span...
-
-
-        // TODO: If stability attrs feature is not enabled
+        if self.cx().features().impl_stability() {
+            return self.evaluate_added_goals_and_make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity));
+        } else {
+            todo!();
+        }
 
     }
 

compiler/rustc_type_ir/src/inherent.rs

@@ -570,6 +570,8 @@ pub trait Features<I: Interner>: Copy {
     fn coroutine_clone(self) -> bool;
 
     fn associated_const_equality(self) -> bool;
+
+    fn impl_stability(self) -> bool;
 }
 
 pub trait DefId<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {