FnCtxt normalization stuff

Author: compiler-errors

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -109,6 +109,9 @@ pub trait AstConv<'tcx> {
     ) -> Ty<'tcx>;
 
     /// Normalize an associated type coming from the user.
+    /// 
+    /// This should only be used by astconv. Use `FnCtxt::normalize`
+    /// or `ObligationCtxt::normalize` in downstream crates.
     fn normalize_ty(&self, span: Span, ty: Ty<'tcx>) -> Ty<'tcx>;
 
     /// Invoked when we encounter an error from some prior pass

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -53,6 +53,8 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         self.ocx.infcx.tcx
     }
 
+    // Convenience function to normalize during wfcheck. This performs
+    // `ObligationCtxt::normalize`, but provides a nice `ObligationCauseCode`.
     fn normalize<T>(&self, span: Span, loc: Option<WellFormedLoc>, value: T) -> T
     where
         T: TypeFoldable<'tcx>,

compiler/rustc_hir_typeck/src/callee.rs

@@ -448,7 +448,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // previously appeared within a `Binder<>` and hence would not
         // have been normalized before.
         let fn_sig = self.replace_bound_vars_with_fresh_vars(call_expr.span, infer::FnCall, fn_sig);
-        let fn_sig = self.normalize_associated_types_in(call_expr.span, fn_sig);
+        let fn_sig = self.normalize(call_expr.span, fn_sig);
 
         // Call the generic checker.
         let expected_arg_tys = self.expected_inputs_for_expected_output(

compiler/rustc_hir_typeck/src/cast.rs

@@ -752,7 +752,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                 match *self.expr_ty.kind() {
                     ty::FnDef(..) => {
                         // Attempt a coercion to a fn pointer type.
-                        let f = fcx.normalize_associated_types_in(
+                        let f = fcx.normalize(
                             self.expr_span,
                             self.expr_ty.fn_sig(fcx.tcx),
                         );

compiler/rustc_hir_typeck/src/closure.rs

@@ -214,7 +214,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             if expected_sig.is_none()
                 && let ty::PredicateKind::Clause(ty::Clause::Projection(proj_predicate)) = bound_predicate.skip_binder()
             {
-                expected_sig = self.normalize_associated_types_in(
+                expected_sig = self.normalize(
                     obligation.cause.span,
                     self.deduce_sig_from_projection(
                     Some(obligation.cause.span),
@@ -623,7 +623,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
         // Astconv can't normalize inputs or outputs with escaping bound vars,
         // so normalize them here, after we've wrapped them in a binder.
-        let result = self.normalize_associated_types_in(self.tcx.hir().span(hir_id), result);
+        let result = self.normalize(self.tcx.hir().span(hir_id), result);
 
         let c_result = self.inh.infcx.canonicalize_response(result);
         self.typeck_results.borrow_mut().user_provided_sigs.insert(expr_def_id, c_result);
@@ -797,10 +797,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) -> ClosureSignatures<'tcx> {
         let liberated_sig =
             self.tcx().liberate_late_bound_regions(expr_def_id.to_def_id(), bound_sig);
-        let liberated_sig = self.inh.normalize_associated_types_in(
+        let liberated_sig = self.normalize(
             body.value.span,
-            self.tcx.hir().local_def_id_to_hir_id(expr_def_id),
-            self.param_env,
             liberated_sig,
         );
         ClosureSignatures { bound_sig, liberated_sig }

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1141,8 +1141,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 return Err(TypeError::IntrinsicCast);
             }
             // The signature must match.
-            let a_sig = self.normalize_associated_types_in(new.span, a_sig);
-            let b_sig = self.normalize_associated_types_in(new.span, b_sig);
+            let (a_sig, b_sig) = self.normalize(new.span, (a_sig, b_sig));
             let sig = self
                 .at(cause, self.param_env)
                 .trace(prev_ty, new_ty)

compiler/rustc_hir_typeck/src/expr.rs

@@ -1664,7 +1664,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         .fields
                         .iter()
                         .map(|f| {
-                            let fru_ty = self.normalize_associated_types_in(
+                            let fru_ty = self.normalize(
                                 expr_span,
                                 self.field_ty(base_expr.span, f, fresh_substs),
                             );
@@ -1749,7 +1749,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         .fields
                         .iter()
                         .map(|f| {
-                            self.normalize_associated_types_in(expr_span, f.ty(self.tcx, substs))
+                            self.normalize(expr_span, f.ty(self.tcx, substs))
                         })
                         .collect(),
                     _ => {

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -344,7 +344,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     {
         debug!("instantiate_type_scheme(value={:?}, substs={:?})", value, substs);
         let value = EarlyBinder(value).subst(self.tcx, substs);
-        let result = self.normalize_associated_types_in(span, value);
+        let result = self.normalize(span, value);
         debug!("instantiate_type_scheme = {:?}", result);
         result
     }
@@ -360,19 +360,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let bounds = self.tcx.predicates_of(def_id);
         let spans: Vec<Span> = bounds.predicates.iter().map(|(_, span)| *span).collect();
         let result = bounds.instantiate(self.tcx, substs);
-        let result = self.normalize_associated_types_in(span, result);
+        let result = self.normalize(span, result);
         debug!(
             "instantiate_bounds(bounds={:?}, substs={:?}) = {:?}, {:?}",
             bounds, substs, result, spans,
         );
         (result, spans)
     }
 
-    pub(in super::super) fn normalize_associated_types_in<T>(&self, span: Span, value: T) -> T
+    pub(in super::super) fn normalize<T>(&self, span: Span, value: T) -> T
     where
         T: TypeFoldable<'tcx>,
     {
-        self.inh.normalize_associated_types_in(span, self.body_id, self.param_env, value)
+        self.register_infer_ok_obligations(
+            self.at(&self.misc(span), self.param_env).normalize(value),
+        )
     }
 
     pub(in super::super) fn normalize_associated_types_in_as_infer_ok<T>(
@@ -487,7 +489,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let span = self.tcx.def_span(anon_const.def_id);
                 let c = ty::Const::from_anon_const(self.tcx, anon_const.def_id);
                 self.register_wf_obligation(c.into(), span, ObligationCauseCode::WellFormed(None));
-                self.normalize_associated_types_in(span, c)
+                self.normalize(span, c)
             }
         }
     }
@@ -580,7 +582,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         field: &'tcx ty::FieldDef,
         substs: SubstsRef<'tcx>,
     ) -> Ty<'tcx> {
-        self.normalize_associated_types_in(span, field.ty(self.tcx, substs))
+        self.normalize(span, field.ty(self.tcx, substs))
     }
 
     pub(in super::super) fn resolve_rvalue_scopes(&self, def_id: DefId) {
@@ -1107,7 +1109,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         if let Res::Local(hid) = res {
             let ty = self.local_ty(span, hid).decl_ty;
-            let ty = self.normalize_associated_types_in(span, ty);
+            let ty = self.normalize(span, ty);
             self.write_ty(hir_id, ty);
             return (ty, res);
         }

compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs

@@ -288,7 +288,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
         if ty.has_escaping_bound_vars() {
             ty // FIXME: normalization and escaping regions
         } else {
-            self.normalize_associated_types_in(span, ty)
+            self.normalize(span, ty)
         }
     }
 

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -759,7 +759,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 debug!("suggest_missing_return_type: expected type {:?}", ty);
                 let bound_vars = self.tcx.late_bound_vars(fn_id);
                 let ty = Binder::bind_with_vars(ty, bound_vars);
-                let ty = self.normalize_associated_types_in(span, ty);
+                let ty = self.normalize(span, ty);
                 let ty = self.tcx.erase_late_bound_regions(ty);
                 if self.can_coerce(expected, ty) {
                     err.subdiagnostic(ExpectedReturnTypeLabel::Other { span, expected });
@@ -920,7 +920,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, ty);
             let bound_vars = self.tcx.late_bound_vars(fn_id);
             let ty = self.tcx.erase_late_bound_regions(Binder::bind_with_vars(ty, bound_vars));
-            let ty = self.normalize_associated_types_in(expr.span, ty);
+            let ty = self.normalize(expr.span, ty);
             let ty = match self.tcx.asyncness(fn_id.owner) {
                 hir::IsAsync::Async => {
                     let infcx = self.tcx.infer_ctxt().build();