Merge collect_mod_item_types query into check_well_formed

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1,7 +1,9 @@
 use crate::autoderef::Autoderef;
+use crate::collect::CollectItemTypesVisitor;
 use crate::constrained_generic_params::{identify_constrained_generic_params, Parameter};
 use crate::errors;
 
+use hir::intravisit::Visitor;
 use rustc_ast as ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_errors::{codes::*, pluralize, struct_span_code_err, Applicability, ErrorGuaranteed};
@@ -225,6 +227,7 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
         ?item.owner_id,
         item.name = ? tcx.def_path_str(def_id)
     );
+    CollectItemTypesVisitor { tcx }.visit_item(item);
 
     let res = match item.kind {
         // Right now we check that every default trait implementation
@@ -336,9 +339,14 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
     res
 }
 
-fn check_foreign_item(tcx: TyCtxt<'_>, item: &hir::ForeignItem<'_>) -> Result<(), ErrorGuaranteed> {
+fn check_foreign_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    item: &'tcx hir::ForeignItem<'tcx>,
+) -> Result<(), ErrorGuaranteed> {
     let def_id = item.owner_id.def_id;
 
+    CollectItemTypesVisitor { tcx }.visit_foreign_item(item);
+
     debug!(
         ?item.owner_id,
         item.name = ? tcx.def_path_str(def_id)
@@ -355,12 +363,14 @@ fn check_foreign_item(tcx: TyCtxt<'_>, item: &hir::ForeignItem<'_>) -> Result<()
     }
 }
 
-fn check_trait_item(
-    tcx: TyCtxt<'_>,
-    trait_item: &hir::TraitItem<'_>,
+fn check_trait_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    trait_item: &'tcx hir::TraitItem<'tcx>,
 ) -> Result<(), ErrorGuaranteed> {
     let def_id = trait_item.owner_id.def_id;
 
+    CollectItemTypesVisitor { tcx }.visit_trait_item(trait_item);
+
     let (method_sig, span) = match trait_item.kind {
         hir::TraitItemKind::Fn(ref sig, _) => (Some(sig), trait_item.span),
         hir::TraitItemKind::Type(_bounds, Some(ty)) => (None, ty.span),
@@ -895,7 +905,12 @@ fn check_object_unsafe_self_trait_by_name(tcx: TyCtxt<'_>, item: &hir::TraitItem
     }
 }
 
-fn check_impl_item(tcx: TyCtxt<'_>, impl_item: &hir::ImplItem<'_>) -> Result<(), ErrorGuaranteed> {
+fn check_impl_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    impl_item: &'tcx hir::ImplItem<'tcx>,
+) -> Result<(), ErrorGuaranteed> {
+    CollectItemTypesVisitor { tcx }.visit_impl_item(impl_item);
+
     let (method_sig, span) = match impl_item.kind {
         hir::ImplItemKind::Fn(ref sig, _) => (Some(sig), impl_item.span),
         // Constrain binding and overflow error spans to `<Ty>` in `type foo = <Ty>`.

compiler/rustc_hir_analysis/src/collect.rs

@@ -20,7 +20,7 @@ use rustc_data_structures::unord::UnordMap;
 use rustc_errors::{Applicability, Diag, ErrorGuaranteed, StashKey};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
-use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{GenericParamKind, Node};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
@@ -52,22 +52,6 @@ mod resolve_bound_vars;
 mod type_of;
 
 ///////////////////////////////////////////////////////////////////////////
-// Main entry point
-
-fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
-    let items = tcx.hir_module_items(module_def_id);
-    let hir = tcx.hir();
-    let _ = items.par_items(|item| Ok(CollectItemTypesVisitor { tcx }.visit_item(hir.item(item))));
-    let _ = items.par_impl_items(|item| {
-        Ok(CollectItemTypesVisitor { tcx }.visit_impl_item(hir.impl_item(item)))
-    });
-    let _ = items.par_trait_items(|item| {
-        Ok(CollectItemTypesVisitor { tcx }.visit_trait_item(hir.trait_item(item)))
-    });
-    let _ = items.par_foreign_items(|item| {
-        Ok(CollectItemTypesVisitor { tcx }.visit_foreign_item(hir.foreign_item(item)))
-    });
-}
 
 pub fn provide(providers: &mut Providers) {
     resolve_bound_vars::provide(providers);
@@ -93,7 +77,6 @@ pub fn provide(providers: &mut Providers) {
         impl_trait_header,
         coroutine_kind,
         coroutine_for_closure,
-        collect_mod_item_types,
         is_type_alias_impl_trait,
         find_field,
         ..*providers
@@ -166,8 +149,8 @@ impl<'v> Visitor<'v> for HirPlaceholderCollector {
     }
 }
 
-struct CollectItemTypesVisitor<'tcx> {
-    tcx: TyCtxt<'tcx>,
+pub struct CollectItemTypesVisitor<'tcx> {
+    pub tcx: TyCtxt<'tcx>,
 }
 
 /// If there are any placeholder types (`_`), emit an error explaining that this is not allowed

compiler/rustc_hir_analysis/src/lib.rs

@@ -159,12 +159,6 @@ pub fn provide(providers: &mut Providers) {
 pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
     let _prof_timer = tcx.sess.timer("type_check_crate");
 
-    // this ensures that later parts of type checking can assume that items
-    // have valid types and not error
-    tcx.sess.time("type_collecting", || {
-        tcx.hir().for_each_module(|module| tcx.ensure().collect_mod_item_types(module))
-    });
-
     if tcx.features().rustc_attrs {
         tcx.sess.time("outlives_testing", || outlives::test::test_inferred_outlives(tcx))?;
     }

compiler/rustc_middle/src/query/mod.rs

@@ -763,6 +763,7 @@ rustc_queries! {
         desc { |tcx| "computing the variances of `{}`", tcx.def_path_str(def_id) }
         cache_on_disk_if { def_id.is_local() }
         separate_provide_extern
+        cycle_delay_bug
     }
 
     /// Maps from thee `DefId` of a type to its (inferred) outlives.
@@ -960,10 +961,6 @@ rustc_queries! {
         ensure_forwards_result_if_red
     }
 
-    query collect_mod_item_types(key: LocalModDefId) {
-        desc { |tcx| "collecting item types in {}", describe_as_module(key, tcx) }
-    }
-
     /// Caches `CoerceUnsized` kinds for impls on custom types.
     query coerce_unsized_info(key: DefId) -> Result<ty::adjustment::CoerceUnsizedInfo, ErrorGuaranteed> {
         desc { |tcx| "computing CoerceUnsized info for `{}`", tcx.def_path_str(key) }

compiler/rustc_middle/src/values.rs

@@ -131,6 +131,27 @@ impl<'tcx> Value<TyCtxt<'tcx>> for ty::EarlyBinder<ty::Binder<'_, ty::FnSig<'_>>
     }
 }
 
+impl<'tcx> Value<TyCtxt<'tcx>> for &[ty::Variance] {
+    fn from_cycle_error(
+        tcx: TyCtxt<'tcx>,
+        cycle_error: &CycleError,
+        _guar: ErrorGuaranteed,
+    ) -> Self {
+        if let Some(frame) = cycle_error.cycle.get(0)
+            && frame.query.dep_kind == dep_kinds::variances_of
+            && let Some(def_id) = frame.query.def_id
+        {
+            let n = tcx.generics_of(def_id).params.len();
+            vec![ty::Variance::Bivariant; n].leak()
+        } else {
+            span_bug!(
+                cycle_error.usage.as_ref().unwrap().0,
+                "only `variances_of` returns `&[ty::Variance]`"
+            );
+        }
+    }
+}
+
 // Take a cycle of `Q` and try `try_cycle` on every permutation, falling back to `otherwise`.
 fn search_for_cycle_permutation<Q, T>(
     cycle: &[Q],