Rollup merge of #101503 - spastorino:add-debug-calls, r=compiler-errors

Add debug calls

`@oli-obk` requested this and other changes as a way of simplifying #101345. This is just going to make the diff of #101345 smaller.

r? `@oli-obk` `@cjgillot`

compiler/rustc_ast_lowering/src/lib.rs

@@ -660,6 +660,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     /// actually used in the HIR, as that would trigger an assertion in the
     /// `HirIdValidator` later on, which makes sure that all `NodeId`s got mapped
     /// properly. Calling the method twice with the same `NodeId` is fine though.
+    #[instrument(level = "debug", skip(self), ret)]
     fn lower_node_id(&mut self, ast_node_id: NodeId) -> hir::HirId {
         assert_ne!(ast_node_id, DUMMY_NODE_ID);
 
@@ -693,6 +694,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     }
 
     /// Generate a new `HirId` without a backing `NodeId`.
+    #[instrument(level = "debug", skip(self), ret)]
     fn next_id(&mut self) -> hir::HirId {
         let owner = self.current_hir_id_owner;
         let local_id = self.item_local_id_counter;
@@ -1382,7 +1384,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     /// added explicitly in the HIR). But this includes all the lifetimes, and we only want to
     /// capture the lifetimes that are referenced in the bounds. Therefore, we add *extra* lifetime parameters
     /// for the lifetimes that get captured (`'x`, in our example above) and reference those.
-    #[instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self), ret)]
     fn lower_opaque_impl_trait(
         &mut self,
         span: Span,
@@ -2148,6 +2150,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         hir::MutTy { ty: self.lower_ty(&mt.ty, itctx), mutbl: mt.mutbl }
     }
 
+    #[instrument(level = "debug", skip(self), ret)]
     fn lower_param_bounds(
         &mut self,
         bounds: &[GenericBound],
@@ -2165,6 +2168,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         bounds.iter().map(move |bound| self.lower_param_bound(bound, itctx))
     }
 
+    #[instrument(level = "debug", skip(self), ret)]
     fn lower_generic_and_bounds(
         &mut self,
         node_id: NodeId,

compiler/rustc_infer/src/infer/outlives/verify.rs

@@ -50,13 +50,13 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn param_bound(&self, param_ty: ty::ParamTy) -> VerifyBound<'tcx> {
-        debug!("param_bound(param_ty={:?})", param_ty);
-
         // Start with anything like `T: 'a` we can scrape from the
         // environment. If the environment contains something like
         // `for<'a> T: 'a`, then we know that `T` outlives everything.
         let declared_bounds_from_env = self.declared_generic_bounds_from_env(param_ty);
+        debug!(?declared_bounds_from_env);
         let mut param_bounds = vec![];
         for declared_bound in declared_bounds_from_env {
             let bound_region = declared_bound.map_bound(|outlives| outlives.1);
@@ -65,13 +65,15 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
                 param_bounds.push(VerifyBound::OutlivedBy(region));
             } else {
                 // This is `for<'a> T: 'a`. This means that `T` outlives everything! All done here.
+                debug!("found that {param_ty:?} outlives any lifetime, returning empty vector");
                 return VerifyBound::AllBounds(vec![]);
             }
         }
 
         // Add in the default bound of fn body that applies to all in
         // scope type parameters:
         if let Some(r) = self.implicit_region_bound {
+            debug!("adding implicit region bound of {r:?}");
             param_bounds.push(VerifyBound::OutlivedBy(r));
         }
 

compiler/rustc_middle/src/ty/generics.rs

@@ -328,6 +328,7 @@ impl<'tcx> GenericPredicates<'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self, tcx))]
     fn instantiate_into(
         &self,
         tcx: TyCtxt<'tcx>,

compiler/rustc_passes/src/hir_id_validator.rs

@@ -103,7 +103,7 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
             self.error(|| {
                 format!(
                     "ItemLocalIds not assigned densely in {}. \
-                Max ItemLocalId = {}, missing IDs = {:?}; seens IDs = {:?}",
+                Max ItemLocalId = {}, missing IDs = {:#?}; seens IDs = {:#?}",
                     self.hir_map.def_path(owner).to_string_no_crate_verbose(),
                     max,
                     missing_items,

compiler/rustc_resolve/src/late/lifetimes.rs

@@ -525,6 +525,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
         match &item.kind {
             hir::ItemKind::Impl(hir::Impl { of_trait, .. }) => {
@@ -839,6 +840,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
         use self::hir::TraitItemKind::*;
         match trait_item.kind {
@@ -888,6 +890,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         use self::hir::ImplItemKind::*;
         match impl_item.kind {

compiler/rustc_trait_selection/src/traits/wf.rs

@@ -434,6 +434,7 @@ impl<'tcx> WfPredicates<'tcx> {
     }
 
     /// Pushes all the predicates needed to validate that `ty` is WF into `out`.
+    #[instrument(level = "debug", skip(self))]
     fn compute(&mut self, arg: GenericArg<'tcx>) {
         let mut walker = arg.walk();
         let param_env = self.param_env;
@@ -488,6 +489,8 @@ impl<'tcx> WfPredicates<'tcx> {
                 }
             };
 
+            debug!("wf bounds for ty={:?} ty.kind={:#?}", ty, ty.kind());
+
             match *ty.kind() {
                 ty::Bool
                 | ty::Char

compiler/rustc_typeck/src/astconv/mod.rs

@@ -2697,6 +2697,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         result_ty
     }
 
+    #[instrument(level = "debug", skip(self), ret)]
     fn impl_trait_ty_to_ty(
         &self,
         def_id: DefId,
@@ -2745,9 +2746,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         });
         debug!("impl_trait_ty_to_ty: substs={:?}", substs);
 
-        let ty = tcx.mk_opaque(def_id, substs);
-        debug!("impl_trait_ty_to_ty: {}", ty);
-        ty
+        tcx.mk_opaque(def_id, substs)
     }
 
     pub fn ty_of_arg(&self, ty: &hir::Ty<'_>, expected_ty: Option<Ty<'tcx>>) -> Ty<'tcx> {

compiler/rustc_typeck/src/collect.rs

@@ -573,6 +573,7 @@ fn get_new_lifetime_name<'tcx>(
 
 /// Returns the predicates defined on `item_def_id` of the form
 /// `X: Foo` where `X` is the type parameter `def_id`.
+#[instrument(level = "trace", skip(tcx))]
 fn type_param_predicates(
     tcx: TyCtxt<'_>,
     (item_def_id, def_id, assoc_name): (DefId, LocalDefId, Ident),
@@ -679,7 +680,7 @@ impl<'tcx> ItemCtxt<'tcx> {
         assoc_name: Option<Ident>,
     ) -> Vec<(ty::Predicate<'tcx>, Span)> {
         let param_def_id = self.tcx.hir().local_def_id(param_id).to_def_id();
-        debug!(?param_def_id);
+        trace!(?param_def_id);
         ast_generics
             .predicates
             .iter()
@@ -708,9 +709,8 @@ impl<'tcx> ItemCtxt<'tcx> {
             .collect()
     }
 
+    #[instrument(level = "trace", skip(self))]
     fn bound_defines_assoc_item(&self, b: &hir::GenericBound<'_>, assoc_name: Ident) -> bool {
-        debug!("bound_defines_assoc_item(b={:?}, assoc_name={:?})", b, assoc_name);
-
         match b {
             hir::GenericBound::Trait(poly_trait_ref, _) => {
                 let trait_ref = &poly_trait_ref.trait_ref;
@@ -2105,11 +2105,10 @@ fn predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> {
 
 /// Returns a list of user-specified type predicates for the definition with ID `def_id`.
 /// N.B., this does not include any implied/inferred constraints.
+#[instrument(level = "trace", skip(tcx), ret)]
 fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> {
     use rustc_hir::*;
 
-    debug!("explicit_predicates_of(def_id={:?})", def_id);
-
     let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
     let node = tcx.hir().get(hir_id);
 
@@ -2224,6 +2223,9 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
         + has_own_self as u32
         + early_bound_lifetimes_from_generics(tcx, ast_generics).count() as u32;
 
+    trace!(?predicates);
+    trace!(?ast_generics);
+
     // Collect the predicates that were written inline by the user on each
     // type parameter (e.g., `<T: Foo>`).
     for param in ast_generics.params {
@@ -2244,7 +2246,9 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
                     Some((param.hir_id, ast_generics.predicates)),
                     param.span,
                 );
+                trace!(?bounds);
                 predicates.extend(bounds.predicates(tcx, param_ty));
+                trace!(?predicates);
             }
             GenericParamKind::Const { .. } => {
                 // Bounds on const parameters are currently not possible.
@@ -2253,6 +2257,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
         }
     }
 
+    trace!(?predicates);
     // Add in the bounds that appear in the where-clause.
     for predicate in ast_generics.predicates {
         match predicate {
@@ -2338,12 +2343,10 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
         );
     }
 
-    let result = ty::GenericPredicates {
+    ty::GenericPredicates {
         parent: generics.parent,
         predicates: tcx.arena.alloc_from_iter(predicates),
-    };
-    debug!("explicit_predicates_of(def_id={:?}) = {:?}", def_id, result);
-    result
+    }
 }
 
 fn const_evaluatable_predicates_of<'tcx>(

compiler/rustc_typeck/src/collect/item_bounds.rs

@@ -53,6 +53,7 @@ fn associated_type_bounds<'tcx>(
 /// impl trait it isn't possible to write a suitable predicate on the
 /// containing function and for type-alias impl trait we don't have a backwards
 /// compatibility issue.
+#[instrument(level = "trace", skip(tcx), ret)]
 fn opaque_type_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
     opaque_def_id: DefId,
@@ -67,6 +68,8 @@ fn opaque_type_bounds<'tcx>(
         let mut bounds = <dyn AstConv<'_>>::compute_bounds(&icx, item_ty, ast_bounds);
         // Opaque types are implicitly sized unless a `?Sized` bound is found
         <dyn AstConv<'_>>::add_implicitly_sized(&icx, &mut bounds, ast_bounds, None, span);
+        debug!(?bounds);
+
         tcx.arena.alloc_from_iter(bounds.predicates(tcx, item_ty))
     })
 }