Auto merge of #117213 - oli-obk:check_item_type_cleanup, r=estebank

 Reorder check_item_type diagnostics so they occur next to the corresponding `check_well_formed` diagnostics

The first commit is just a cleanup.

The second commit moves most checks from `check_mod_item_types` into `check_well_formed`, invoking the checks in lockstep per-item instead of iterating over all items twice.

Author: bors

compiler/rustc_hir_analysis/src/check/check.rs

@@ -8,7 +8,7 @@ use rustc_attr as attr;
 use rustc_errors::{ErrorGuaranteed, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind};
-use rustc_hir::def_id::LocalModDefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::Node;
 use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt};
 use rustc_infer::traits::{Obligation, TraitEngineExt as _};
@@ -198,8 +198,8 @@ fn check_static_inhabited(tcx: TyCtxt<'_>, def_id: LocalDefId) {
 
 /// Checks that an opaque type does not contain cycles and does not use `Self` or `T::Foo`
 /// projections that would result in "inheriting lifetimes".
-fn check_opaque(tcx: TyCtxt<'_>, id: hir::ItemId) {
-    let item = tcx.hir().item(id);
+fn check_opaque(tcx: TyCtxt<'_>, def_id: LocalDefId) {
+    let item = tcx.hir().expect_item(def_id);
     let hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) = item.kind else {
         tcx.dcx().span_delayed_bug(item.span, "expected opaque item");
         return;
@@ -440,40 +440,31 @@ fn check_static_linkage(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     }
 }
 
-fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
-    debug!(
-        "check_item_type(it.def_id={:?}, it.name={})",
-        id.owner_id,
-        tcx.def_path_str(id.owner_id)
-    );
+pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let _indenter = indenter();
-    match tcx.def_kind(id.owner_id) {
+    match tcx.def_kind(def_id) {
         DefKind::Static(..) => {
-            tcx.ensure().typeck(id.owner_id.def_id);
-            maybe_check_static_with_link_section(tcx, id.owner_id.def_id);
-            check_static_inhabited(tcx, id.owner_id.def_id);
-            check_static_linkage(tcx, id.owner_id.def_id);
+            tcx.ensure().typeck(def_id);
+            maybe_check_static_with_link_section(tcx, def_id);
+            check_static_inhabited(tcx, def_id);
+            check_static_linkage(tcx, def_id);
         }
         DefKind::Const => {
-            tcx.ensure().typeck(id.owner_id.def_id);
+            tcx.ensure().typeck(def_id);
         }
         DefKind::Enum => {
-            check_enum(tcx, id.owner_id.def_id);
+            check_enum(tcx, def_id);
         }
         DefKind::Fn => {} // entirely within check_item_body
         DefKind::Impl { of_trait } => {
-            if of_trait && let Some(impl_trait_ref) = tcx.impl_trait_ref(id.owner_id) {
-                check_impl_items_against_trait(
-                    tcx,
-                    id.owner_id.def_id,
-                    impl_trait_ref.instantiate_identity(),
-                );
-                check_on_unimplemented(tcx, id);
+            if of_trait && let Some(impl_trait_ref) = tcx.impl_trait_ref(def_id) {
+                check_impl_items_against_trait(tcx, def_id, impl_trait_ref.instantiate_identity());
+                check_on_unimplemented(tcx, def_id);
             }
         }
         DefKind::Trait => {
-            let assoc_items = tcx.associated_items(id.owner_id);
-            check_on_unimplemented(tcx, id);
+            let assoc_items = tcx.associated_items(def_id);
+            check_on_unimplemented(tcx, def_id);
 
             for &assoc_item in assoc_items.in_definition_order() {
                 match assoc_item.kind {
@@ -482,43 +473,43 @@ fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
                         forbid_intrinsic_abi(tcx, assoc_item.ident(tcx).span, abi);
                     }
                     ty::AssocKind::Type if assoc_item.defaultness(tcx).has_value() => {
-                        let trait_args = GenericArgs::identity_for_item(tcx, id.owner_id);
+                        let trait_args = GenericArgs::identity_for_item(tcx, def_id);
                         let _: Result<_, rustc_errors::ErrorGuaranteed> = check_type_bounds(
                             tcx,
                             assoc_item,
                             assoc_item,
-                            ty::TraitRef::new(tcx, id.owner_id.to_def_id(), trait_args),
+                            ty::TraitRef::new(tcx, def_id.to_def_id(), trait_args),
                         );
                     }
                     _ => {}
                 }
             }
         }
         DefKind::Struct => {
-            check_struct(tcx, id.owner_id.def_id);
+            check_struct(tcx, def_id);
         }
         DefKind::Union => {
-            check_union(tcx, id.owner_id.def_id);
+            check_union(tcx, def_id);
         }
         DefKind::OpaqueTy => {
-            let origin = tcx.opaque_type_origin(id.owner_id.def_id);
+            let origin = tcx.opaque_type_origin(def_id);
             if let hir::OpaqueTyOrigin::FnReturn(fn_def_id)
             | hir::OpaqueTyOrigin::AsyncFn(fn_def_id) = origin
                 && let hir::Node::TraitItem(trait_item) = tcx.hir_node_by_def_id(fn_def_id)
                 && let (_, hir::TraitFn::Required(..)) = trait_item.expect_fn()
             {
                 // Skip opaques from RPIT in traits with no default body.
             } else {
-                check_opaque(tcx, id);
+                check_opaque(tcx, def_id);
             }
         }
         DefKind::TyAlias => {
-            let pty_ty = tcx.type_of(id.owner_id).instantiate_identity();
-            let generics = tcx.generics_of(id.owner_id);
+            let pty_ty = tcx.type_of(def_id).instantiate_identity();
+            let generics = tcx.generics_of(def_id);
             check_type_params_are_used(tcx, generics, pty_ty);
         }
         DefKind::ForeignMod => {
-            let it = tcx.hir().item(id);
+            let it = tcx.hir().expect_item(def_id);
             let hir::ItemKind::ForeignMod { abi, items } = it.kind else {
                 return;
             };
@@ -589,19 +580,19 @@ fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
             }
         }
         DefKind::GlobalAsm => {
-            let it = tcx.hir().item(id);
+            let it = tcx.hir().expect_item(def_id);
             let hir::ItemKind::GlobalAsm(asm) = it.kind else {
                 span_bug!(it.span, "DefKind::GlobalAsm but got {:#?}", it)
             };
-            InlineAsmCtxt::new_global_asm(tcx).check_asm(asm, id.owner_id.def_id);
+            InlineAsmCtxt::new_global_asm(tcx).check_asm(asm, def_id);
         }
         _ => {}
     }
 }
 
-pub(super) fn check_on_unimplemented(tcx: TyCtxt<'_>, item: hir::ItemId) {
+pub(super) fn check_on_unimplemented(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     // an error would be reported if this fails.
-    let _ = OnUnimplementedDirective::of_item(tcx, item.owner_id.to_def_id());
+    let _ = OnUnimplementedDirective::of_item(tcx, def_id.to_def_id());
 }
 
 pub(super) fn check_specialization_validity<'tcx>(
@@ -1309,16 +1300,6 @@ pub(super) fn check_type_params_are_used<'tcx>(
     }
 }
 
-pub(super) fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
-    let module = tcx.hir_module_items(module_def_id);
-    for id in module.items() {
-        check_item_type(tcx, id);
-    }
-    if module_def_id == LocalModDefId::CRATE_DEF_ID {
-        super::entry::check_for_entry_fn(tcx);
-    }
-}
-
 fn async_opaque_type_cycle_error(tcx: TyCtxt<'_>, span: Span) -> ErrorGuaranteed {
     struct_span_err!(tcx.dcx(), span, E0733, "recursion in an `async fn` requires boxing")
         .span_label(span, "recursive `async fn`")

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -75,7 +75,6 @@ pub use check::check_abi;
 
 use std::num::NonZeroU32;
 
-use check::check_mod_item_types;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::ErrorGuaranteed;
 use rustc_errors::{pluralize, struct_span_err, Diagnostic, DiagnosticBuilder};
@@ -110,7 +109,6 @@ pub fn provide(providers: &mut Providers) {
     wfcheck::provide(providers);
     *providers = Providers {
         adt_destructor,
-        check_mod_item_types,
         region_scope_tree,
         collect_return_position_impl_trait_in_trait_tys,
         compare_impl_const: compare_impl_item::compare_impl_const_raw,

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -172,7 +172,7 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
         item.name = ? tcx.def_path_str(def_id)
     );
 
-    match item.kind {
+    let res = match item.kind {
         // Right now we check that every default trait implementation
         // has an implementation of itself. Basically, a case like:
         //
@@ -271,7 +271,11 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
             }
         }
         _ => Ok(()),
-    }
+    };
+
+    crate::check::check::check_item_type(tcx, def_id);
+
+    res
 }
 
 fn check_foreign_item(tcx: TyCtxt<'_>, item: &hir::ForeignItem<'_>) -> Result<(), ErrorGuaranteed> {
@@ -1909,7 +1913,11 @@ fn check_mod_type_wf(tcx: TyCtxt<'_>, module: LocalModDefId) -> Result<(), Error
     let mut res = items.par_items(|item| tcx.ensure().check_well_formed(item.owner_id));
     res = res.and(items.par_impl_items(|item| tcx.ensure().check_well_formed(item.owner_id)));
     res = res.and(items.par_trait_items(|item| tcx.ensure().check_well_formed(item.owner_id)));
-    res.and(items.par_foreign_items(|item| tcx.ensure().check_well_formed(item.owner_id)))
+    res = res.and(items.par_foreign_items(|item| tcx.ensure().check_well_formed(item.owner_id)));
+    if module == LocalModDefId::CRATE_DEF_ID {
+        super::entry::check_for_entry_fn(tcx);
+    }
+    res
 }
 
 fn error_392(tcx: TyCtxt<'_>, span: Span, param_name: Symbol) -> DiagnosticBuilder<'_> {

compiler/rustc_hir_analysis/src/lib.rs

@@ -200,18 +200,9 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
         })?;
     }
 
-    let errs = tcx.sess.time("wf_checking", || {
+    tcx.sess.time("wf_checking", || {
         tcx.hir().try_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.
-    tcx.sess.time("item_types_checking", || {
-        tcx.hir().for_each_module(|module| tcx.ensure().check_mod_item_types(module))
-    });
-
-    // HACK: `check_mod_type_wf` may spuriously emit errors due to `span_delayed_bug`, even if
-    // those errors only actually get emitted in `check_mod_item_types`.
-    errs?;
+    })?;
 
     if tcx.features().rustc_attrs {
         tcx.sess.track_errors(|| collect::test_opaque_hidden_types(tcx))?;

compiler/rustc_middle/src/query/mod.rs

@@ -938,10 +938,6 @@ rustc_queries! {
         desc { |tcx| "checking naked functions in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_item_types(key: LocalModDefId) -> () {
-        desc { |tcx| "checking item types in {}", describe_as_module(key, tcx) }
-    }
-
     query check_mod_privacy(key: LocalModDefId) -> () {
         desc { |tcx| "checking privacy in {}", describe_as_module(key.to_local_def_id(), tcx) }
     }

src/librustdoc/core.rs

@@ -323,7 +323,9 @@ pub(crate) fn run_global_ctxt(
         tcx.hir().try_par_for_each_module(|module| tcx.ensure().check_mod_type_wf(module))
     });
     tcx.sess.time("item_types_checking", || {
-        tcx.hir().for_each_module(|module| tcx.ensure().check_mod_item_types(module))
+        tcx.hir().for_each_module(|module| {
+            let _ = tcx.ensure().check_mod_type_wf(module);
+        });
     });
 
     tcx.dcx().abort_if_errors();

tests/ui/associated-types/associated-types-no-suitable-supertrait.stderr

@@ -1,3 +1,15 @@
+error[E0277]: the trait bound `(T, U): Get` is not satisfied
+  --> $DIR/associated-types-no-suitable-supertrait.rs:22:5
+   |
+LL |     fn uhoh<U:Get>(&self, foo: U, bar: <(T, U) as Get>::Value) {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Get` is not implemented for `(T, U)`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/associated-types-no-suitable-supertrait.rs:12:1
+   |
+LL | trait Get {
+   | ^^^^^^^^^
+
 error[E0277]: the trait bound `(T, U): Get` is not satisfied
   --> $DIR/associated-types-no-suitable-supertrait.rs:22:40
    |
@@ -21,18 +33,6 @@ help: consider further restricting `Self`
 LL |     fn uhoh<U:Get>(&self, foo: U, bar: <Self as Get>::Value) where Self: Get {}
    |                                                              +++++++++++++++
 
-error[E0277]: the trait bound `(T, U): Get` is not satisfied
-  --> $DIR/associated-types-no-suitable-supertrait.rs:22:5
-   |
-LL |     fn uhoh<U:Get>(&self, foo: U, bar: <(T, U) as Get>::Value) {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Get` is not implemented for `(T, U)`
-   |
-help: this trait has no implementations, consider adding one
-  --> $DIR/associated-types-no-suitable-supertrait.rs:12:1
-   |
-LL | trait Get {
-   | ^^^^^^^^^
-
 error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/associated-types/defaults-cyclic-fail-1.rs

@@ -24,13 +24,13 @@ impl Tr for u32 {
 // ...but not in an impl that redefines one of the types.
 impl Tr for bool {
     type A = Box<Self::B>;
-    //~^ ERROR overflow evaluating the requirement `<bool as Tr>::B == _`
+    //~^ ERROR overflow evaluating the requirement `<bool as Tr>::A == _`
 }
 // (the error is shown twice for some reason)
 
 impl Tr for usize {
     type B = &'static Self::A;
-    //~^ ERROR overflow evaluating the requirement `<usize as Tr>::A == _`
+    //~^ ERROR overflow evaluating the requirement `<usize as Tr>::B == _`
 }
 
 fn main() {

tests/ui/associated-types/defaults-cyclic-fail-1.stderr

@@ -1,10 +1,10 @@
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B == _`
+error[E0275]: overflow evaluating the requirement `<bool as Tr>::A == _`
   --> $DIR/defaults-cyclic-fail-1.rs:26:14
    |
 LL |     type A = Box<Self::B>;
    |              ^^^^^^^^^^^^
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::A == _`
+error[E0275]: overflow evaluating the requirement `<usize as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-1.rs:32:14
    |
 LL |     type B = &'static Self::A;

tests/ui/associated-types/defaults-cyclic-fail-2.rs

@@ -25,13 +25,13 @@ impl Tr for u32 {
 
 impl Tr for bool {
     type A = Box<Self::B>;
-    //~^ ERROR overflow evaluating the requirement `<bool as Tr>::B == _`
+    //~^ ERROR overflow evaluating the requirement `<bool as Tr>::A == _`
 }
 // (the error is shown twice for some reason)
 
 impl Tr for usize {
     type B = &'static Self::A;
-    //~^ ERROR overflow evaluating the requirement `<usize as Tr>::A == _`
+    //~^ ERROR overflow evaluating the requirement `<usize as Tr>::B == _`
 }
 
 fn main() {