From 33614886812c6c4a3b68a3cdd5b3bb5a3626ce49 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 22 Mar 2024 13:13:40 -0400
Subject: [PATCH] Always encode implied_predicates query for traits

With associated type bounds enabled, the implied_predicates and super_predicates
queries may differ for traits, since associated type bounds are also
implied but are not counted as super predicates.
---
 .../src/rmeta/decoder/cstore_impl.rs          | 13 +------------
 compiler/rustc_metadata/src/rmeta/encoder.rs  |  1 +
 .../implied-predicates.rs                     |  1 +
 .../implied-predicates.stderr                 | 19 -------------------
 4 files changed, 3 insertions(+), 31 deletions(-)
 delete mode 100644 tests/ui/associated-type-bounds/implied-predicates.stderr

diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 1aabd296641..b69a295f010 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -211,6 +211,7 @@ fn into_args(self) -> (DefId, SimplifiedType) {
     generics_of => { table }
     inferred_outlives_of => { table_defaulted_array }
     super_predicates_of => { table }
+    implied_predicates_of => { table }
     type_of => { table }
     type_alias_is_lazy => { cdata.root.tables.type_alias_is_lazy.get(cdata, def_id.index) }
     variances_of => { table }
@@ -276,18 +277,6 @@ fn into_args(self) -> (DefId, SimplifiedType) {
             .map(|lazy| lazy.decode((cdata, tcx)))
             .process_decoded(tcx, || panic!("{def_id:?} does not have trait_impl_trait_tys")))
     }
-    implied_predicates_of => {
-        cdata
-            .root
-            .tables
-            .implied_predicates_of
-            .get(cdata, def_id.index)
-            .map(|lazy| lazy.decode((cdata, tcx)))
-            .unwrap_or_else(|| {
-                debug_assert_eq!(tcx.def_kind(def_id), DefKind::Trait);
-                tcx.super_predicates_of(def_id)
-            })
-    }
 
     associated_types_for_impl_traits_in_associated_fn => { table_defaulted_array }
 
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 42724f7dd2b..61060038b50 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1435,6 +1435,7 @@ fn encode_def_ids(&mut self) {
             if let DefKind::Trait = def_kind {
                 record!(self.tables.trait_def[def_id] <- self.tcx.trait_def(def_id));
                 record!(self.tables.super_predicates_of[def_id] <- self.tcx.super_predicates_of(def_id));
+                record!(self.tables.implied_predicates_of[def_id] <- self.tcx.implied_predicates_of(def_id));
 
                 let module_children = self.tcx.module_children_local(local_id);
                 record_array!(self.tables.module_children_non_reexports[def_id] <-
diff --git a/tests/ui/associated-type-bounds/implied-predicates.rs b/tests/ui/associated-type-bounds/implied-predicates.rs
index 91b8a94c64f..e97d7a396c4 100644
--- a/tests/ui/associated-type-bounds/implied-predicates.rs
+++ b/tests/ui/associated-type-bounds/implied-predicates.rs
@@ -1,4 +1,5 @@
 //@ aux-build:implied-predicates.rs
+//@ check-pass
 
 extern crate implied_predicates;
 use implied_predicates::Bar;
diff --git a/tests/ui/associated-type-bounds/implied-predicates.stderr b/tests/ui/associated-type-bounds/implied-predicates.stderr
deleted file mode 100644
index 6527f9f3641..00000000000
--- a/tests/ui/associated-type-bounds/implied-predicates.stderr
+++ /dev/null
@@ -1,19 +0,0 @@
-error[E0277]: the trait bound `<B as Super>::SuperAssoc: implied_predicates::Bound` is not satisfied
-  --> $DIR/implied-predicates.rs:6:11
-   |
-LL | fn bar<B: Bar>() {}
-   |           ^^^ the trait `implied_predicates::Bound` is not implemented for `<B as Super>::SuperAssoc`
-   |
-note: required by a bound in `Bar`
-  --> $DIR/auxiliary/implied-predicates.rs:1:34
-   |
-LL | pub trait Bar: Super<SuperAssoc: Bound> {}
-   |                                  ^^^^^ required by this bound in `Bar`
-help: consider further restricting the associated type
-   |
-LL | fn bar<B: Bar>() where <B as Super>::SuperAssoc: implied_predicates::Bound {}
-   |                  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0277`.