From 980ce8aed4ea0c89ccc41bb1cd41e1d382af65e5 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev@sunfishcode.online>
Date: Mon, 18 Nov 2024 09:58:11 -0800
Subject: [PATCH] Avoid emitting redundant `#[allow(dead_code)]` directives.

Only emit `#[allow(dead_code)]` on top-level modules, and emit
`#[rustfmt::skip]` on all top-level modules.
---
 crates/rust/src/interface.rs |  1 -
 crates/rust/src/lib.rs       | 30 ++++++++++++++++--------------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/crates/rust/src/interface.rs b/crates/rust/src/interface.rs
index 8a7468960..ba42bbff0 100644
--- a/crates/rust/src/interface.rs
+++ b/crates/rust/src/interface.rs
@@ -439,7 +439,6 @@ macro_rules! {macro_name} {{
         };
         let module = format!(
             "\
-                #[allow(dead_code, clippy::all)]
                 pub mod {snake} {{
                     {used_static}
                     {module}
diff --git a/crates/rust/src/lib.rs b/crates/rust/src/lib.rs
index 8c546c1fd..2d7f71e5b 100644
--- a/crates/rust/src/lib.rs
+++ b/crates/rust/src/lib.rs
@@ -293,23 +293,25 @@ impl RustWasm {
             cur.contents.push(module);
         }
 
-        // Disable rustfmt. By default we already format the code
-        // using prettyplease, so we don't want `cargo fmt` to create
-        // extra diffs for users to deal with.
-        if self.opts.format {
-            uwriteln!(self.src, "#[rustfmt::skip]");
-        }
-
-        emit(&mut self.src, map);
-        fn emit(me: &mut Source, module: Module) {
+        emit(&mut self.src, map, &self.opts, true);
+        fn emit(me: &mut Source, module: Module, opts: &Opts, toplevel: bool) {
             for (name, submodule) in module.submodules {
-                // Ignore dead-code warnings. If the bindings are only used
-                // within a crate, and not exported to a different crate, some
-                // parts may be unused, and that's ok.
-                uwriteln!(me, "#[allow(dead_code)]");
+                if toplevel {
+                    // Disable rustfmt. By default we already format the code
+                    // using prettyplease, so we don't want `cargo fmt` to create
+                    // extra diffs for users to deal with.
+                    if opts.format {
+                        uwriteln!(me, "#[rustfmt::skip]");
+                    }
+
+                    // Ignore dead-code and clippy warnings. If the bindings are
+                    // only used within a crate, and not exported to a different
+                    // crate, some parts may be unused, and that's ok.
+                    uwriteln!(me, "#[allow(dead_code, clippy::all)]");
+                }
 
                 uwriteln!(me, "pub mod {name} {{");
-                emit(me, submodule);
+                emit(me, submodule, opts, false);
                 uwriteln!(me, "}}");
             }
             for submodule in module.contents {