From 7d20bdf1bdf797c42384c6e88c90b14e8a60cbf0 Mon Sep 17 00:00:00 2001
From: Gun9niR <gun9nir.guo@gmail.com>
Date: Fri, 27 Jan 2023 12:48:44 +0000
Subject: [PATCH] forward rustdoc from config to opts

---
 src/common/proc_macro/src/config.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/common/proc_macro/src/config.rs b/src/common/proc_macro/src/config.rs
index cacec6d280181..f553cc6237ee3 100644
--- a/src/common/proc_macro/src/config.rs
+++ b/src/common/proc_macro/src/config.rs
@@ -55,6 +55,13 @@ pub fn produce_cli_overwrite(input: DeriveInput) -> TokenStream {
             {
                 let field_ident = field.ident;
                 let field_type = field.ty;
+                // Forward rustdoc to derived struct.
+                let field_docs: Vec<_> = field
+                    .attrs
+                    .into_iter()
+                    .filter(|attr| attr.path.is_ident("doc"))
+                    .collect();
+
                 // If the original type is wrapped by `Option`, keep it.
                 // Otherwise extract the inner type.
                 let is_option = {
@@ -92,6 +99,7 @@ pub fn produce_cli_overwrite(input: DeriveInput) -> TokenStream {
 
                 let opt_attrs = gen_clap_attribute(cli_overwrite_attrs);
                 let opt_field = quote! {
+                    #(#field_docs)*
                     #opt_attrs
                     pub #field_ident: #field_type
                 };