Perform wf checking per module.

compiler/rustc_middle/src/query/mod.rs

@@ -826,6 +826,10 @@ rustc_queries! {
         desc { |tcx| "checking that impls are well-formed in {}", describe_as_module(key, tcx) }
     }
 
+    query check_mod_type_wf(key: LocalDefId) -> () {
+        desc { |tcx| "checking that types are well-formed in {}", describe_as_module(key, tcx) }
+    }
+
     query collect_mod_item_types(key: LocalDefId) -> () {
         desc { |tcx| "collecting item types in {}", describe_as_module(key, tcx) }
     }

compiler/rustc_typeck/src/check/mod.rs

@@ -99,8 +99,6 @@ pub use expectation::Expectation;
 pub use fn_ctxt::*;
 use hir::def::CtorOf;
 pub use inherited::{Inherited, InheritedBuilder};
-use wfcheck::check_well_formed;
-pub(crate) use wfcheck::check_wf_new;
 
 use crate::astconv::AstConv;
 use crate::check::gather_locals::GatherLocalsVisitor;
@@ -243,6 +241,7 @@ impl<'tcx> EnclosingBreakables<'tcx> {
 
 pub fn provide(providers: &mut Providers) {
     method::provide(providers);
+    wfcheck::provide(providers);
     *providers = Providers {
         typeck_item_bodies,
         typeck_const_arg,
@@ -251,7 +250,6 @@ pub fn provide(providers: &mut Providers) {
         has_typeck_results,
         adt_destructor,
         used_trait_imports,
-        check_well_formed,
         check_mod_item_types,
         region_scope_tree,
         ..*providers

compiler/rustc_typeck/src/check/wfcheck.rs

@@ -14,6 +14,7 @@ use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::outlives::obligations::TypeOutlives;
 use rustc_infer::infer::region_constraints::GenericKind;
 use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
+use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts, Subst};
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
@@ -67,7 +68,7 @@ impl<'tcx> CheckWfFcxBuilder<'tcx> {
     }
 }
 
-pub(crate) fn check_well_formed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
+fn check_well_formed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let node = tcx.hir().expect_owner(def_id);
     match node {
         hir::OwnerNode::Crate(_) => {}
@@ -1858,8 +1859,8 @@ fn check_false_global_bounds(fcx: &FnCtxt<'_, '_>, mut span: Span, id: hir::HirI
     fcx.select_all_obligations_or_error();
 }
 
-pub(crate) fn check_wf_new(tcx: TyCtxt<'_>) {
-    let items = tcx.hir_crate_items(());
+fn check_mod_type_wf(tcx: TyCtxt<'_>, module: LocalDefId) {
+    let items = tcx.hir_module_items(module);
     par_for_each_in(items.items(), |item| tcx.ensure().check_well_formed(item.def_id));
     par_for_each_in(items.impl_items(), |item| tcx.ensure().check_well_formed(item.def_id));
     par_for_each_in(items.trait_items(), |item| tcx.ensure().check_well_formed(item.def_id));
@@ -1948,3 +1949,7 @@ fn error_392(
     err.span_label(span, "unused parameter");
     err
 }
+
+pub fn provide(providers: &mut Providers) {
+    *providers = Providers { check_mod_type_wf, check_well_formed, ..*providers };
+}

compiler/rustc_typeck/src/lib.rs

@@ -525,7 +525,9 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
     }
 
     tcx.sess.track_errors(|| {
-        tcx.sess.time("wf_checking", || check::check_wf_new(tcx));
+        tcx.sess.time("wf_checking", || {
+            tcx.hir().par_for_each_module(|module| tcx.ensure().check_mod_type_wf(module))
+        });
     })?;
 
     // NOTE: This is copy/pasted in librustdoc/core.rs and should be kept in sync.

src/test/ui/issues/issue-20413.rs

@@ -1,5 +1,5 @@
 trait Foo {
-  fn answer(self);
+    fn answer(self);
 }
 
 struct NoData<T>;
@@ -13,11 +13,11 @@ impl<T> Foo for T where NoData<T>: Foo {
 }
 
 trait Bar {
-  fn answer(self);
+    fn answer(self);
 }
 
 trait Baz {
-  fn answer(self);
+    fn answer(self);
 }
 
 struct AlmostNoData<T>(Option<T>);