self review

Author: lcnr

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -490,10 +490,18 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         }
         trace!(?curr_projected_ty);
 
-        // Need to renormalize `a` as typecheck may have failed to normalize
-        // higher-ranked aliases if normalization was ambiguous due to inference.
-        let a = self.normalize(ty::Unnormalized::new_wip(a), locations);
-        let ty = self.normalize(ty::Unnormalized::new_wip(curr_projected_ty.ty), locations);
+        // Need to renormalize `a` in the old solver as typecheck may have failed
+        // to normalize higher-ranked aliases if normalization was ambiguous due
+        // to inference.
+        //
+        // We properly normalize higher-ranked aliases during writeback with the
+        // new solver, so this is no longer necessary.
+        let mut a = a;
+        let mut ty = curr_projected_ty.ty;
+        if !self.infcx.next_trait_solver() {
+            a = self.normalize(ty::Unnormalized::new_wip(a), locations);
+            ty = self.normalize(ty::Unnormalized::new_wip(ty), locations);
+        }
         self.relate_types(ty, v.xform(ty::Contravariant), a, locations, category)?;
 
         Ok(())

compiler/rustc_const_eval/src/const_eval/valtrees.rs

@@ -199,10 +199,12 @@ fn reconstruct_place_meta<'tcx>(
 
     let mut last_valtree = valtree;
     // Traverse the type, and update `last_valtree` as we go.
+    //
+    // FIXME(#155345): Missing normalization call
     let tail = tcx.struct_tail_raw(
         layout.ty,
         &ObligationCause::dummy(),
-        |ty| ty.skip_normalization(),
+        |ty| ty.skip_norm_wip(),
         || {
             let branches = last_valtree.to_branch();
             last_valtree = branches.last().unwrap().to_value().valtree;

compiler/rustc_hir_analysis/src/collect/dump.rs

@@ -155,7 +155,7 @@ pub(crate) fn vtables<'tcx>(tcx: TyCtxt<'tcx>) {
             }
             hir::ItemKind::TyAlias(..) => {
                 let ty = tcx.type_of(def_id).instantiate_identity();
-                if ty.skip_normalization().has_non_region_param() {
+                if ty.has_non_region_param() {
                     tcx.dcx().span_err(
                         attr_span,
                         "`rustc_dump_vtable` must be applied to non-generic type",

compiler/rustc_hir_typeck/src/expectation.rs

@@ -80,7 +80,7 @@ impl<'a, 'tcx> Expectation<'tcx> {
         };
         let cause = ObligationCause::misc(span, fcx.body_id);
 
-        // FIXME: This is not right, even in the old solver...
+        // FIXME(#155345): Missing normalization call
         match fcx.tcx.struct_tail_raw(ty, &cause, |ty| ty.skip_normalization(), || {}).kind() {
             ty::Slice(_) | ty::Str | ty::Dynamic(..) => ExpectRvalueLikeUnsized(ty),
             _ => ExpectHasType(ty),

compiler/rustc_middle/src/ty/sty.rs

@@ -1818,7 +1818,7 @@ impl<'tcx> Ty<'tcx> {
         if pointee_ty.has_trivial_sizedness(tcx, SizedTraitKind::Sized) {
             tcx.types.unit
         } else {
-            match pointee_ty.ptr_metadata_ty_or_tail(tcx, |x| x.skip_normalization()) {
+            match pointee_ty.ptr_metadata_ty_or_tail(tcx, |x| x.skip_norm_wip()) {
                 Ok(metadata_ty) => metadata_ty,
                 Err(tail_ty) => {
                     let metadata_def_id = tcx.require_lang_item(LangItem::Metadata, DUMMY_SP);