tracing::instrument cleanup

7 files changed, 18 insertions, 40 deletions

diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
index 99d8f57505c..d4350aa5734 100644
--- a/compiler/rustc_infer/src/infer/combine.rs
+++ b/compiler/rustc_infer/src/infer/combine.rs
@@ -391,7 +391,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
     /// Preconditions:
     ///
     /// - `for_vid` is a "root vid"
-    #[instrument(skip(self), level = "trace")]
+    #[instrument(skip(self), level = "trace", ret)]
     fn generalize(
         &self,
         ty: Ty<'tcx>,
@@ -435,15 +435,8 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
             cache: SsoHashMap::new(),
         };
 
-        let ty = match generalize.relate(ty, ty) {
-            Ok(ty) => ty,
-            Err(e) => {
-                debug!(?e, "failure");
-                return Err(e);
-            }
-        };
+        let ty = generalize.relate(ty, ty)?;
         let needs_wf = generalize.needs_wf;
-        trace!(?ty, ?needs_wf, "success");
         Ok(Generalization { ty, needs_wf })
     }
 
@@ -499,6 +492,7 @@ struct Generalizer<'cx, 'tcx> {
 /// Result from a generalization operation. This includes
 /// not only the generalized type, but also a bool flag
 /// indicating whether further WF checks are needed.
+#[derive(Debug)]
 struct Generalization<'tcx> {
     ty: Ty<'tcx>,
 
@@ -856,10 +850,9 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
         Ok(a.rebind(self.relate(a.skip_binder(), b.skip_binder())?))
     }
 
-    #[instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self), ret)]
     fn tys(&mut self, t: Ty<'tcx>, _t: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
         debug_assert_eq!(t, _t);
-        debug!("ConstInferUnifier: t={:?}", t);
 
         match t.kind() {
             &ty::Infer(ty::TyVar(vid)) => {
@@ -883,12 +876,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                             .borrow_mut()
                             .type_variables()
                             .new_var(self.for_universe, origin);
-                        let u = self.tcx().mk_ty_var(new_var_id);
-                        debug!(
-                            "ConstInferUnifier: replacing original vid={:?} with new={:?}",
-                            vid, u
-                        );
-                        Ok(u)
+                        Ok(self.tcx().mk_ty_var(new_var_id))
                     }
                 }
             }
@@ -939,7 +927,6 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
         _c: ty::Const<'tcx>,
     ) -> RelateResult<'tcx, ty::Const<'tcx>> {
         debug_assert_eq!(c, _c);
-        debug!("ConstInferUnifier: c={:?}", c);
 
         match c.kind() {
             ty::ConstKind::Infer(InferConst::Var(vid)) => {
diff --git a/compiler/rustc_infer/src/infer/higher_ranked/mod.rs b/compiler/rustc_infer/src/infer/higher_ranked/mod.rs
index d0d9efe152c..67426fcf0fe 100644
--- a/compiler/rustc_infer/src/infer/higher_ranked/mod.rs
+++ b/compiler/rustc_infer/src/infer/higher_ranked/mod.rs
@@ -69,7 +69,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     /// For more details visit the relevant sections of the [rustc dev guide].
     ///
     /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/hrtb.html
-    #[instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self), ret)]
     pub fn replace_bound_vars_with_placeholders<T>(&self, binder: ty::Binder<'tcx, T>) -> T
     where
         T: TypeFoldable<'tcx> + Copy,
@@ -104,9 +104,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             },
         };
 
-        let result = self.tcx.replace_bound_vars_uncached(binder, delegate);
-        debug!(?next_universe, ?result);
-        result
+        debug!(?next_universe);
+        self.tcx.replace_bound_vars_uncached(binder, delegate)
     }
 
     /// See [RegionConstraintCollector::leak_check][1].
diff --git a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
index 3783cfb4cc5..13b7e8eb964 100644
--- a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
+++ b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
@@ -333,9 +333,9 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
     ///
     /// Neither `a` nor `b` may be an inference variable (hence the
     /// term "concrete regions").
-    #[instrument(level = "trace", skip(self))]
+    #[instrument(level = "trace", skip(self), ret)]
     fn lub_concrete_regions(&self, a: Region<'tcx>, b: Region<'tcx>) -> Region<'tcx> {
-        let r = match (*a, *b) {
+        match (*a, *b) {
             (ReLateBound(..), _) | (_, ReLateBound(..)) | (ReErased, _) | (_, ReErased) => {
                 bug!("cannot relate region: LUB({:?}, {:?})", a, b);
             }
@@ -399,11 +399,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
                     self.tcx().lifetimes.re_static
                 }
             }
-        };
-
-        debug!("lub_concrete_regions({:?}, {:?}) = {:?}", a, b, r);
-
-        r
+        }
     }
 
     /// After expansion is complete, go and check upper bounds (i.e.,
diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
index e7e93116a66..bb6f6ae60e2 100644
--- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs
+++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
@@ -542,7 +542,7 @@ where
         true
     }
 
-    #[instrument(skip(self, info), level = "trace")]
+    #[instrument(skip(self, info), level = "trace", ret)]
     fn relate_with_variance<T: Relate<'tcx>>(
         &mut self,
         variance: ty::Variance,
@@ -560,8 +560,6 @@ where
 
         self.ambient_variance = old_ambient_variance;
 
-        debug!(?r);
-
         Ok(r)
     }
 
diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index 233a5004a39..d45adf43abf 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -390,7 +390,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         });
     }
 
-    #[instrument(skip(self), level = "trace")]
+    #[instrument(skip(self), level = "trace", ret)]
     pub fn opaque_type_origin(&self, def_id: LocalDefId, span: Span) -> Option<OpaqueTyOrigin> {
         let opaque_hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
         let parent_def_id = match self.defining_use_anchor {
@@ -421,16 +421,14 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         in_definition_scope.then_some(*origin)
     }
 
-    #[instrument(skip(self), level = "trace")]
+    #[instrument(skip(self), level = "trace", ret)]
     fn opaque_ty_origin_unchecked(&self, def_id: LocalDefId, span: Span) -> OpaqueTyOrigin {
-        let origin = match self.tcx.hir().expect_item(def_id).kind {
+        match self.tcx.hir().expect_item(def_id).kind {
             hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) => origin,
             ref itemkind => {
                 span_bug!(span, "weird opaque type: {:?}, {:#?}", def_id, itemkind)
             }
-        };
-        trace!(?origin);
-        origin
+        }
     }
 }
 
diff --git a/compiler/rustc_infer/src/infer/opaque_types/table.rs b/compiler/rustc_infer/src/infer/opaque_types/table.rs
index fb12da0cc13..4d124554afb 100644
--- a/compiler/rustc_infer/src/infer/opaque_types/table.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types/table.rs
@@ -29,7 +29,7 @@ impl<'tcx> OpaqueTypeStorage<'tcx> {
         }
     }
 
-    #[instrument(level = "debug")]
+    #[instrument(level = "debug", ret)]
     pub fn take_opaque_types(&mut self) -> OpaqueTypeMap<'tcx> {
         std::mem::take(&mut self.opaque_types)
     }
diff --git a/compiler/rustc_infer/src/infer/outlives/mod.rs b/compiler/rustc_infer/src/infer/outlives/mod.rs
index 2a085288fb7..2d19d1823fd 100644
--- a/compiler/rustc_infer/src/infer/outlives/mod.rs
+++ b/compiler/rustc_infer/src/infer/outlives/mod.rs
@@ -9,7 +9,7 @@ pub mod verify;
 use rustc_middle::traits::query::OutlivesBound;
 use rustc_middle::ty;
 
-#[instrument(level = "debug", skip(param_env))]
+#[instrument(level = "debug", skip(param_env), ret)]
 pub fn explicit_outlives_bounds<'tcx>(
     param_env: ty::ParamEnv<'tcx>,
 ) -> impl Iterator<Item = OutlivesBound<'tcx>> + 'tcx {