From f8a0cc26817eac3ea1edec8d6eeef5657f583a5a Mon Sep 17 00:00:00 2001
From: Alejandro Cabeza Romero <alex93cabeza@gmail.com>
Date: Thu, 19 Dec 2024 16:25:16 +0100
Subject: [PATCH] Feature gate instrument imports on overwatch-derive.

---
 overwatch-derive/Cargo.toml |  3 +++
 overwatch-derive/src/lib.rs | 13 ++++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/overwatch-derive/Cargo.toml b/overwatch-derive/Cargo.toml
index 31564c2..a98c374 100644
--- a/overwatch-derive/Cargo.toml
+++ b/overwatch-derive/Cargo.toml
@@ -21,6 +21,9 @@ exclude = [
 [lib]
 proc-macro = true
 
+[features]
+instrumentation = []
+
 [dependencies]
 heck = "0.4"
 syn = "1.0"
diff --git a/overwatch-derive/src/lib.rs b/overwatch-derive/src/lib.rs
index 8ec3430..281302c 100644
--- a/overwatch-derive/src/lib.rs
+++ b/overwatch-derive/src/lib.rs
@@ -3,6 +3,8 @@ mod utils;
 use proc_macro_error::{abort_call_site, proc_macro_error};
 use quote::{format_ident, quote};
 use syn::{punctuated::Punctuated, token::Comma, Data, DeriveInput, Field, Generics};
+#[cfg(feature = "instrumentation")]
+use tracing::instrument;
 
 #[proc_macro_derive(Services)]
 #[proc_macro_error]
@@ -185,7 +187,8 @@ fn generate_start_all_impl(fields: &Punctuated<Field, Comma>) -> proc_macro2::To
     });
 
     quote! {
-        #[::tracing::instrument(skip(self), err)]
+
+        #[cfg_attr(feature = "instrumentation", instrument(skip(self), err))]
         fn start_all(&mut self) -> Result<::overwatch_rs::overwatch::ServicesLifeCycleHandle, ::overwatch_rs::overwatch::Error> {
             ::std::result::Result::Ok([#( #call_start ),*].try_into()?)
         }
@@ -205,7 +208,7 @@ fn generate_start_impl(fields: &Punctuated<Field, Comma>) -> proc_macro2::TokenS
     });
 
     quote! {
-        #[::tracing::instrument(skip(self), err)]
+        #[cfg_attr(feature = "instrumentation", instrument(skip(self), err))]
         fn start(&mut self, service_id: ::overwatch_rs::services::ServiceId) -> Result<(), ::overwatch_rs::overwatch::Error> {
             match service_id {
                 #( #cases ),*
@@ -226,7 +229,7 @@ fn generate_stop_impl(fields: &Punctuated<Field, Comma>) -> proc_macro2::TokenSt
     });
 
     quote! {
-        #[::tracing::instrument(skip(self), err)]
+        #[cfg_attr(feature = "instrumentation", instrument(skip(self), err))]
         fn stop(&mut self, service_id: ::overwatch_rs::services::ServiceId) -> Result<(), ::overwatch_rs::overwatch::Error> {
             match service_id {
                 #( #cases ),*
@@ -252,7 +255,7 @@ fn generate_request_relay_impl(fields: &Punctuated<Field, Comma>) -> proc_macro2
     });
 
     quote! {
-        #[::tracing::instrument(skip(self), err)]
+        #[cfg_attr(feature = "instrumentation", instrument(skip(self), err))]
         fn request_relay(&mut self, service_id: ::overwatch_rs::services::ServiceId) -> ::overwatch_rs::services::relay::RelayResult {
             {
                 match service_id {
@@ -282,7 +285,7 @@ fn generate_update_settings_impl(fields: &Punctuated<Field, Comma>) -> proc_macr
     });
 
     quote! {
-        #[::tracing::instrument(skip(self, settings), err)]
+        #[cfg_attr(feature = "instrumentation", instrument(skip(self, settings), err))]
         fn update_settings(&mut self, settings: Self::Settings) -> Result<(), ::overwatch_rs::overwatch::Error> {
             let Self::Settings {
                 #( #fields_settings ),*