From 61e2b4f9446636cfb9abd8b038a0923bac3f2520 Mon Sep 17 00:00:00 2001
From: Esteve Fernandez <esteve@apache.org>
Date: Tue, 7 Nov 2023 18:20:20 +0100
Subject: [PATCH] Allow rustdoc to run without a ROS distribution

---
 rclrs/Cargo.toml          |   6 ++
 rclrs/build.rs            |  11 ++-
 rclrs/src/rcl_bindings.rs | 164 ++++++++++++++++++++++++++++++++++----
 3 files changed, 164 insertions(+), 17 deletions(-)

diff --git a/rclrs/Cargo.toml b/rclrs/Cargo.toml
index 01c6d082a..2022f0898 100644
--- a/rclrs/Cargo.toml
+++ b/rclrs/Cargo.toml
@@ -16,6 +16,7 @@ path = "src/lib.rs"
 [dependencies]
 # Needed for dynamically finding type support libraries 
 ament_rs = { version = "0.2", optional = true }
+cfg-if = "1.0.0"
 # Needed for clients
 futures = "0.3"
 # Needed for dynamic messages
@@ -33,3 +34,8 @@ bindgen = "0.66.1"
 
 [features]
 dyn_msg = ["ament_rs", "libloading"]
+generate_docs = []
+
+[package.metadata.docs.rs]
+
+features = ["generate_docs"]
diff --git a/rclrs/build.rs b/rclrs/build.rs
index fe8cd8b9a..753345974 100644
--- a/rclrs/build.rs
+++ b/rclrs/build.rs
@@ -18,7 +18,16 @@ fn get_env_var_or_abort(env_var: &'static str) -> String {
 }
 
 fn main() {
-    let ros_distro = get_env_var_or_abort(ROS_DISTRO);
+    let ros_distro = if let Ok(value) = env::var(ROS_DISTRO) {
+        value
+    } else {
+        println!(
+            "{} environment variable not set - please source ROS 2 installation first.",
+            ROS_DISTRO
+        );
+        return;
+    };
+
     println!("cargo:rustc-cfg=ros_distro=\"{ros_distro}\"");
 
     let mut builder = bindgen::Builder::default()
diff --git a/rclrs/src/rcl_bindings.rs b/rclrs/src/rcl_bindings.rs
index 245430269..aad2545c7 100644
--- a/rclrs/src/rcl_bindings.rs
+++ b/rclrs/src/rcl_bindings.rs
@@ -1,16 +1,148 @@
-#![allow(dead_code)]
-#![allow(deref_nullptr)]
-#![allow(non_upper_case_globals)]
-#![allow(non_camel_case_types)]
-#![allow(non_snake_case)]
-// Added to avoid clippy complaining about u128 types not being FFI safe
-// Caused by https://github.com/ros2/ros2/issues/1374 in iron and newer
-// See https://github.com/ros2-rust/ros2_rust/issues/320
-#![allow(improper_ctypes)]
-#![allow(improper_ctypes_definitions)]
-#![allow(clippy::all)]
-#![allow(missing_docs)]
-
-include!(concat!(env!("OUT_DIR"), "/rcl_bindings_generated.rs"));
-
-pub const RMW_GID_STORAGE_SIZE: usize = rmw_gid_storage_size_constant;
+cfg_if::cfg_if! {
+    if #[cfg(feature="generate_docs")] {
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_wait_set_t;
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_clock_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_node_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_context_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_guard_condition_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_subscription_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_request_id_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_service_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_client_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_publisher_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_time_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_arguments_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_allocator_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_ret_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_clock_type_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_node_options_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_names_and_types_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_topic_endpoint_info_array_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcutils_string_array_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_names_and_types_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_topic_endpoint_info_array_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_node_params_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_variant_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_params_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_message_info_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_qos_durability_policy_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_qos_history_policy_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_qos_liveliness_policy_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_qos_profile_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_qos_reliability_policy_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rosidl_message_type_support_t;
+
+        pub const RMW_GID_STORAGE_SIZE: usize = 16;
+
+        extern "C" {
+            pub fn rcl_context_is_valid(context: *const rcl_context_t) -> bool;
+        }
+    } else {
+        #![allow(dead_code)]
+        #![allow(deref_nullptr)]
+        #![allow(non_upper_case_globals)]
+        #![allow(non_camel_case_types)]
+        #![allow(non_snake_case)]
+        // Added to avoid clippy complaining about u128 types not being FFI safe
+        // Caused by https://github.com/ros2/ros2/issues/1374 in iron and newer
+        // See https://github.com/ros2-rust/ros2_rust/issues/320
+        #![allow(improper_ctypes)]
+        #![allow(improper_ctypes_definitions)]
+        #![allow(clippy::all)]
+        #![allow(missing_docs)]
+        include!(concat!(env!("OUT_DIR"), "/rcl_bindings_generated.rs"));
+
+        pub const RMW_GID_STORAGE_SIZE: usize = rmw_gid_storage_size_constant;
+    }
+}