From f755eb439012c75bf1056520491e7d2492a2a18e Mon Sep 17 00:00:00 2001
From: Maxim Vezenov <mvezenov@gmail.com>
Date: Tue, 8 Oct 2024 12:12:01 +0100
Subject: [PATCH 1/2] do not warn when a nested struct is provided as input to
 main

---
 compiler/noirc_frontend/src/elaborator/mod.rs | 12 +++-------
 .../noirc_frontend/src/tests/unused_items.rs  | 22 +++++++++++++++++++
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/compiler/noirc_frontend/src/elaborator/mod.rs b/compiler/noirc_frontend/src/elaborator/mod.rs
index bd78febc1d0..ddbb80e2bfc 100644
--- a/compiler/noirc_frontend/src/elaborator/mod.rs
+++ b/compiler/noirc_frontend/src/elaborator/mod.rs
@@ -846,6 +846,9 @@ impl<'context> Elaborator<'context> {
                 for generic in generics {
                     self.mark_parameter_type_as_used(generic);
                 }
+                for (_, typ) in struct_type.borrow().get_fields(generics) {
+                    self.mark_parameter_type_as_used(&typ);
+                }
             }
             Type::Alias(alias_type, generics) => {
                 self.mark_parameter_type_as_used(&alias_type.borrow().get_type(generics));
@@ -872,15 +875,6 @@ impl<'context> Elaborator<'context> {
             | Type::Forall(..)
             | Type::Error => (),
         }
-
-        if let Type::Alias(alias_type, generics) = typ {
-            self.mark_parameter_type_as_used(&alias_type.borrow().get_type(generics));
-            return;
-        }
-
-        if let Type::Struct(struct_type, _generics) = typ {
-            self.mark_struct_as_constructed(struct_type.clone());
-        }
     }
 
     fn run_function_lints(&mut self, func: &FuncMeta, modifiers: &FunctionModifiers) {
diff --git a/compiler/noirc_frontend/src/tests/unused_items.rs b/compiler/noirc_frontend/src/tests/unused_items.rs
index 4d8e504b705..9f5a079b90b 100644
--- a/compiler/noirc_frontend/src/tests/unused_items.rs
+++ b/compiler/noirc_frontend/src/tests/unused_items.rs
@@ -210,3 +210,25 @@ fn warns_on_unused_global() {
     assert_eq!(ident.to_string(), "foo");
     assert_eq!(item.item_type(), "global");
 }
+
+#[test]
+fn no_warning_on_inner_struct_when_parent_is_used() {
+    let src = r#" 
+    struct Bar {
+        inner: [Field; 3],
+    }
+
+    struct Foo {
+        a: Field,
+        bar: Bar,
+    }
+
+    fn main(foos: [Foo; 1]) {
+        assert_eq(foos[0].a, 10);
+    }
+    "#;
+
+    let errors = get_program_errors(src);
+    println!("{errors:?}");
+    assert_eq!(errors.len(), 0);
+}

From 61782298d2f442ec3b015587878d3b4a60cfdb59 Mon Sep 17 00:00:00 2001
From: Maxim Vezenov <mvezenov@gmail.com>
Date: Tue, 8 Oct 2024 07:16:17 -0400
Subject: [PATCH 2/2] Update compiler/noirc_frontend/src/tests/unused_items.rs

---
 compiler/noirc_frontend/src/tests/unused_items.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/compiler/noirc_frontend/src/tests/unused_items.rs b/compiler/noirc_frontend/src/tests/unused_items.rs
index 9f5a079b90b..80b6c7db09a 100644
--- a/compiler/noirc_frontend/src/tests/unused_items.rs
+++ b/compiler/noirc_frontend/src/tests/unused_items.rs
@@ -229,6 +229,5 @@ fn no_warning_on_inner_struct_when_parent_is_used() {
     "#;
 
     let errors = get_program_errors(src);
-    println!("{errors:?}");
     assert_eq!(errors.len(), 0);
 }