From 364a5d4b542618b6db6cfab3f4a0c31d04020765 Mon Sep 17 00:00:00 2001
From: Santiago Pastorino <spastorino@gmail.com>
Date: Mon, 20 Mar 2023 18:19:20 -0300
Subject: [PATCH] Do not consider synthesized RPITITs on missing items checks

---
 compiler/rustc_hir_analysis/src/check/mod.rs  |  5 ++++-
 ...ct-to-rpitit-with-no-value.current.stderr} |  4 ++--
 ...roject-to-rpitit-with-no-value.next.stderr | 21 +++++++++++++++++++
 .../dont-project-to-rpitit-with-no-value.rs   |  5 ++++-
 4 files changed, 31 insertions(+), 4 deletions(-)
 rename tests/ui/impl-trait/in-trait/{dont-project-to-rpitit-with-no-value.stderr => dont-project-to-rpitit-with-no-value.current.stderr} (87%)
 create mode 100644 tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.next.stderr

diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 9acfc1b3d2924..bcbb49232902c 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -202,8 +202,11 @@ fn missing_items_err(
     missing_items: &[ty::AssocItem],
     full_impl_span: Span,
 ) {
+    let missing_items =
+        missing_items.iter().filter(|trait_item| tcx.opt_rpitit_info(trait_item.def_id).is_none());
+
     let missing_items_msg = missing_items
-        .iter()
+        .clone()
         .map(|trait_item| trait_item.name.to_string())
         .collect::<Vec<_>>()
         .join("`, `");
diff --git a/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.stderr b/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.current.stderr
similarity index 87%
rename from tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.stderr
rename to tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.current.stderr
index d7f2e460fb0b9..b8a793e1a7bb5 100644
--- a/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.stderr
+++ b/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.current.stderr
@@ -1,5 +1,5 @@
 warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/dont-project-to-rpitit-with-no-value.rs:1:12
+  --> $DIR/dont-project-to-rpitit-with-no-value.rs:4:12
    |
 LL | #![feature(return_position_impl_trait_in_trait)]
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -8,7 +8,7 @@ LL | #![feature(return_position_impl_trait_in_trait)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0046]: not all trait items implemented, missing: `foo`
-  --> $DIR/dont-project-to-rpitit-with-no-value.rs:9:1
+  --> $DIR/dont-project-to-rpitit-with-no-value.rs:12:1
    |
 LL |     fn foo(&self) -> impl Sized;
    |     ---------------------------- `foo` from trait
diff --git a/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.next.stderr b/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.next.stderr
new file mode 100644
index 0000000000000..b8a793e1a7bb5
--- /dev/null
+++ b/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.next.stderr
@@ -0,0 +1,21 @@
+warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/dont-project-to-rpitit-with-no-value.rs:4:12
+   |
+LL | #![feature(return_position_impl_trait_in_trait)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0046]: not all trait items implemented, missing: `foo`
+  --> $DIR/dont-project-to-rpitit-with-no-value.rs:12:1
+   |
+LL |     fn foo(&self) -> impl Sized;
+   |     ---------------------------- `foo` from trait
+...
+LL | impl MyTrait for i32 {
+   | ^^^^^^^^^^^^^^^^^^^^ missing `foo` in implementation
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0046`.
diff --git a/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs b/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs
index 746a4a929aeb1..8329ce1f835d0 100644
--- a/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs
+++ b/tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs
@@ -1,3 +1,6 @@
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
+
 #![feature(return_position_impl_trait_in_trait)]
 //~^ WARN the feature `return_position_impl_trait_in_trait` is incomplete
 
@@ -7,7 +10,7 @@ trait MyTrait {
 }
 
 impl MyTrait for i32 {
-//~^ ERROR not all trait items implemented, missing: `foo`
+    //~^ ERROR not all trait items implemented, missing: `foo`
     fn bar(&self) -> impl Sized {
         self.foo()
     }