From e087871915a46943db670b3e16bd12f25a1d11a2 Mon Sep 17 00:00:00 2001
From: Jack Huey <31162821+jackh726@users.noreply.github.com>
Date: Tue, 9 Aug 2022 20:23:40 -0400
Subject: [PATCH] Make the GATS self outlives error take into GATs in the
 inputs

---
 compiler/rustc_typeck/src/check/wfcheck.rs          |  2 +-
 .../generic-associated-types/self-outlives-lint.rs  | 13 +++++++++++++
 .../self-outlives-lint.stderr                       | 13 ++++++++++++-
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs
index d0334cd0df7..dbbae3e8a64 100644
--- a/compiler/rustc_typeck/src/check/wfcheck.rs
+++ b/compiler/rustc_typeck/src/check/wfcheck.rs
@@ -383,7 +383,7 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                             tcx,
                             param_env,
                             item_hir_id,
-                            sig.output(),
+                            sig.inputs_and_output,
                             // We also assume that all of the function signature's parameter types
                             // are well formed.
                             &sig.inputs().iter().copied().collect(),
diff --git a/src/test/ui/generic-associated-types/self-outlives-lint.rs b/src/test/ui/generic-associated-types/self-outlives-lint.rs
index 300907adbfc..9bb42d4ff1c 100644
--- a/src/test/ui/generic-associated-types/self-outlives-lint.rs
+++ b/src/test/ui/generic-associated-types/self-outlives-lint.rs
@@ -210,4 +210,17 @@ trait StaticReturnAndTakes<'a> {
     fn bar<'b>(&self, arg: Self::Y<'b>);
 }
 
+// We require bounds when the GAT appears in the inputs
+trait Input {
+    type Item<'a>;
+    //~^ missing required
+    fn takes_item<'a>(&'a self, item: Self::Item<'a>);
+}
+
+// We don't require bounds when the GAT appears in the where clauses
+trait WhereClause {
+    type Item<'a>;
+    fn takes_item<'a>(&'a self) where Self::Item<'a>: ;
+}
+
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/self-outlives-lint.stderr b/src/test/ui/generic-associated-types/self-outlives-lint.stderr
index fdb1f50a776..a43b35bd79c 100644
--- a/src/test/ui/generic-associated-types/self-outlives-lint.stderr
+++ b/src/test/ui/generic-associated-types/self-outlives-lint.stderr
@@ -163,5 +163,16 @@ LL |     type Fut<'out>;
    = note: this bound is currently required to ensure that impls have maximum flexibility
    = note: we are soliciting feedback, see issue #87479 <https://github.com/rust-lang/rust/issues/87479> for more information
 
-error: aborting due to 15 previous errors
+error: missing required bound on `Item`
+  --> $DIR/self-outlives-lint.rs:215:5
+   |
+LL |     type Item<'a>;
+   |     ^^^^^^^^^^^^^-
+   |                  |
+   |                  help: add the required where clause: `where Self: 'a`
+   |
+   = note: this bound is currently required to ensure that impls have maximum flexibility
+   = note: we are soliciting feedback, see issue #87479 <https://github.com/rust-lang/rust/issues/87479> for more information
+
+error: aborting due to 16 previous errors