From a1d181d740df13972533475b4b35d59678b3ab50 Mon Sep 17 00:00:00 2001
From: Lenko Donchev <lenko.donchev@gmail.com>
Date: Wed, 5 Jul 2023 20:19:14 -0500
Subject: [PATCH] Added additional visit steps to visit_generic_param() in
 order to avoid ICE on no bound vars.

---
 .../src/collect/resolve_bound_vars.rs         | 31 +++++++++----------
 tests/ui/closures/issue-112547.rs             | 15 +++++++++
 tests/ui/closures/issue-112547.stderr         | 23 ++++++++++++++
 3 files changed, 53 insertions(+), 16 deletions(-)
 create mode 100644 tests/ui/closures/issue-112547.rs
 create mode 100644 tests/ui/closures/issue-112547.stderr

diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
index a39cfd7b6e169..d9207f2de52c0 100644
--- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
+++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
@@ -856,22 +856,6 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
         let scope = Scope::TraitRefBoundary { s: self.scope };
         self.with(scope, |this| {
             walk_list!(this, visit_generic_param, generics.params);
-            for param in generics.params {
-                match param.kind {
-                    GenericParamKind::Lifetime { .. } => {}
-                    GenericParamKind::Type { default, .. } => {
-                        if let Some(ty) = default {
-                            this.visit_ty(ty);
-                        }
-                    }
-                    GenericParamKind::Const { ty, default } => {
-                        this.visit_ty(ty);
-                        if let Some(default) = default {
-                            this.visit_body(this.tcx.hir().body(default.body));
-                        }
-                    }
-                }
-            }
             walk_list!(this, visit_where_predicate, generics.predicates);
         })
     }
@@ -1000,6 +984,21 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
                 // like implicit `?Sized` or const-param-has-ty predicates.
             }
         }
+
+        match p.kind {
+            GenericParamKind::Lifetime { .. } => {}
+            GenericParamKind::Type { default, .. } => {
+                if let Some(ty) = default {
+                    self.visit_ty(ty);
+                }
+            }
+            GenericParamKind::Const { ty, default } => {
+                self.visit_ty(ty);
+                if let Some(default) = default {
+                    self.visit_body(self.tcx.hir().body(default.body));
+                }
+            }
+        }
     }
 }
 
diff --git a/tests/ui/closures/issue-112547.rs b/tests/ui/closures/issue-112547.rs
new file mode 100644
index 0000000000000..8ecb2abccd4f9
--- /dev/null
+++ b/tests/ui/closures/issue-112547.rs
@@ -0,0 +1,15 @@
+#![feature(non_lifetime_binders)]
+        //~^ WARNING the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
+
+pub fn bar()
+where
+    for<const N: usize = {
+    (||1usize)()
+}> V: IntoIterator
+//~^ ERROR cannot find type `V` in this scope [E0412]
+{
+}
+
+fn main() {
+    bar();
+}
diff --git a/tests/ui/closures/issue-112547.stderr b/tests/ui/closures/issue-112547.stderr
new file mode 100644
index 0000000000000..d86b05dc6a7bf
--- /dev/null
+++ b/tests/ui/closures/issue-112547.stderr
@@ -0,0 +1,23 @@
+error[E0412]: cannot find type `V` in this scope
+  --> $DIR/issue-112547.rs:8:4
+   |
+LL | }> V: IntoIterator
+   |    ^ not found in this scope
+   |
+help: you might be missing a type parameter
+   |
+LL | pub fn bar<V>()
+   |           +++
+
+warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/issue-112547.rs:1:12
+   |
+LL | #![feature(non_lifetime_binders)]
+   |            ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0412`.