Revert "Auto merge of #92306 - Aaron1011:opaque-type-op, r=oli-obk"

This reverts commit 1f0a96862a, reversing
changes made to bf242bb119.

compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs

@@ -4,7 +4,6 @@ use crate::traits::engine::TraitEngineExt as _;
 use crate::traits::query::type_op::TypeOpOutput;
 use crate::traits::query::Fallible;
 use crate::traits::TraitEngine;
-use rustc_infer::infer::region_constraints::RegionConstraintData;
 use rustc_infer::traits::TraitEngineExt as _;
 use rustc_span::source_map::DUMMY_SP;
 
@@ -32,9 +31,6 @@ where
     G: Fn() -> String,
 {
     type Output = R;
-    /// We can't do any custom error reporting for `CustomTypeOp`, so
-    /// we can use `!` to enforce that the implementation never provides it.
-    type ErrorInfo = !;
 
     /// Processes the operation and all resulting obligations,
     /// returning the final result along with any region constraints
@@ -44,7 +40,7 @@ where
             info!("fully_perform({:?})", self);
         }
 
-        Ok(scrape_region_constraints(infcx, || (self.closure)(infcx))?.0)
+        scrape_region_constraints(infcx, || (self.closure)(infcx))
     }
 }
 
@@ -59,10 +55,10 @@ where
 
 /// Executes `op` and then scrapes out all the "old style" region
 /// constraints that result, creating query-region-constraints.
-pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
+fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
     infcx: &InferCtxt<'_, 'tcx>,
     op: impl FnOnce() -> Fallible<InferOk<'tcx, R>>,
-) -> Fallible<(TypeOpOutput<'tcx, Op>, RegionConstraintData<'tcx>)> {
+) -> Fallible<TypeOpOutput<'tcx, Op>> {
     let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
 
     // During NLL, we expect that nobody will register region
@@ -101,18 +97,12 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
     );
 
     if region_constraints.is_empty() {
-        Ok((
-            TypeOpOutput { output: value, constraints: None, error_info: None },
-            region_constraint_data,
-        ))
+        Ok(TypeOpOutput { output: value, constraints: None, canonicalized_query: None })
     } else {
-        Ok((
-            TypeOpOutput {
-                output: value,
-                constraints: Some(Rc::new(region_constraints)),
-                error_info: None,
-            },
-            region_constraint_data,
-        ))
+        Ok(TypeOpOutput {
+            output: value,
+            constraints: Some(Rc::new(region_constraints)),
+            canonicalized_query: None,
+        })
     }
 }

compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs

@@ -28,7 +28,6 @@ pub use rustc_middle::traits::query::type_op::*;
 /// cannot be completed).
 pub trait TypeOp<'tcx>: Sized + fmt::Debug {
     type Output;
-    type ErrorInfo;
 
     /// Processes the operation and all resulting obligations,
     /// returning the final result along with any region constraints
@@ -42,8 +41,9 @@ pub struct TypeOpOutput<'tcx, Op: TypeOp<'tcx>> {
     pub output: Op::Output,
     /// Any region constraints from performing the type op.
     pub constraints: Option<Rc<QueryRegionConstraints<'tcx>>>,
-    /// Used for error reporting to be able to rerun the query
-    pub error_info: Option<Op::ErrorInfo>,
+    /// The canonicalized form of the query.
+    /// This for error reporting to be able to rerun the query.
+    pub canonicalized_query: Option<Canonical<'tcx, Op>>,
 }
 
 /// "Query type ops" are type ops that are implemented using a
@@ -119,11 +119,10 @@ where
     Q: QueryTypeOp<'tcx>,
 {
     type Output = Q::QueryResponse;
-    type ErrorInfo = Canonical<'tcx, ParamEnvAnd<'tcx, Q>>;
 
     fn fully_perform(self, infcx: &InferCtxt<'_, 'tcx>) -> Fallible<TypeOpOutput<'tcx, Self>> {
         let mut region_constraints = QueryRegionConstraints::default();
-        let (output, error_info, mut obligations, _) =
+        let (output, canonicalized_query, mut obligations, _) =
             Q::fully_perform_into(self, infcx, &mut region_constraints)?;
 
         // Typically, instantiating NLL query results does not
@@ -161,6 +160,6 @@ where
         let region_constraints =
             if region_constraints.is_empty() { None } else { Some(Rc::new(region_constraints)) };
 
-        Ok(TypeOpOutput { output, constraints: region_constraints, error_info })
+        Ok(TypeOpOutput { output, constraints: region_constraints, canonicalized_query })
     }
 }