Allow rustdoc to run without a ROS distribution

.github/workflows/rust.yml

@@ -87,7 +87,12 @@ jobs:
         for path in $(colcon list | awk '$3 == "(ament_cargo)" { print $2 }'); do
         cd $path
         echo "Running clippy in $path"
-        cargo clippy --all-targets --all-features -- -D warnings
+        # Run clippy for all features except generate_docs (needed for docs.rs)
+        if [ "$(basename $path)" = "rclrs" ]; then
+          cargo clippy --all-targets -F default,dyn_msg -- -D warnings
+        else
+          cargo clippy --all-targets --all-features -- -D warnings
+        fi
         cd -
         done
 
@@ -98,7 +103,14 @@ jobs:
         for path in $(colcon list | awk '$3 == "(ament_cargo)" && $1 != "examples_rclrs_minimal_pub_sub" && $1 != "examples_rclrs_minimal_client_service" { print $2 }'); do
         cd $path
         echo "Running cargo test in $path"
-        cargo test --all-features
+        # Run cargo test for all features except generate_docs (needed for docs.rs)
+        if [ "$(basename $path)" = "rclrs" ]; then
+          cargo test -F default,dyn_msg
+        elif [ "$(basename $path)" = "rosidl_runtime_rs" ]; then
+          cargo test -F default
+        else
+          cargo test --all-features
+        fi
         cd -
         done
 

rclrs/Cargo.toml

@@ -16,6 +16,9 @@ path = "src/lib.rs"
 [dependencies]
 # Needed for dynamically finding type support libraries 
 ament_rs = { version = "0.2", optional = true }
+# Needed for uploading documentation to docs.rs
+cfg-if = "1.0.0"
+
 # Needed for clients
 futures = "0.3"
 # Needed for dynamic messages
@@ -30,6 +33,15 @@ tempfile = "3.3.0"
 [build-dependencies]
 # Needed for FFI
 bindgen = "0.66.1"
+# Needed for uploading documentation to docs.rs
+cfg-if = "1.0.0"
 
 [features]
+default = []
 dyn_msg = ["ament_rs", "libloading"]
+# This feature is solely for the purpose of being able to generate documetation without a ROS installation
+# The only intended usage of this feature is for docs.rs builders to work.
+generate_docs = ["rosidl_runtime_rs/generate_docs"]
+
+[package.metadata.docs.rs]
+features = ["generate_docs"]

rclrs/build.rs

@@ -18,7 +18,21 @@ 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 {
+        let error_msg =
+            "ROS_DISTRO environment variable not set - please source ROS 2 installation first.";
+        cfg_if::cfg_if! {
+            if #[cfg(feature="generate_docs")] {
+                println!("{}", error_msg);
+                return;
+            } else {
+                panic!("{}", error_msg);
+            }
+        }
+    };
+
     println!("cargo:rustc-cfg=ros_distro=\"{ros_distro}\"");
 
     let mut builder = bindgen::Builder::default()

rclrs/src/arguments.rs

@@ -149,7 +149,7 @@ mod tests {
         .map(|x| x.to_string());
 
         let non_ros_args: Vec<String> = extract_non_ros_args(input_args).unwrap();
-        let expected = vec!["non-ros1", "non-ros2", "non-ros3"];
+        let expected = ["non-ros1", "non-ros2", "non-ros3"];
 
         if non_ros_args.len() != expected.len() {
             return Err(format!(

rclrs/src/rcl_bindings.rs

@@ -11,6 +11,140 @@
 #![allow(clippy::all)]
 #![allow(missing_docs)]
 
-include!(concat!(env!("OUT_DIR"), "/rcl_bindings_generated.rs"));
+cfg_if::cfg_if! {
+    if #[cfg(feature="generate_docs")] {
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_allocator_t;
 
-pub const RMW_GID_STORAGE_SIZE: usize = rmw_gid_storage_size_constant;
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_arguments_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_client_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_clock_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_clock_type_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_names_and_types_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_node_options_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_node_params_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_node_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_params_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_publisher_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_ret_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_service_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_subscription_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_topic_endpoint_info_array_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_variant_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcl_wait_set_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rcutils_string_array_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_message_info_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_names_and_types_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 rmw_request_id_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_time_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rmw_topic_endpoint_info_array_t;
+
+        #[repr(C)]
+        #[derive(Debug)]
+        pub struct rosidl_message_type_support_t;
+
+        pub const RMW_GID_STORAGE_SIZE: usize = 24;
+
+        extern "C" {
+            pub fn rcl_context_is_valid(context: *const rcl_context_t) -> bool;
+        }
+    } else {
+        include!(concat!(env!("OUT_DIR"), "/rcl_bindings_generated.rs"));
+
+        pub const RMW_GID_STORAGE_SIZE: usize = rmw_gid_storage_size_constant;
+    }
+}

rosidl_runtime_rs/Cargo.toml

@@ -17,8 +17,20 @@ path = "src/lib.rs"
 # formats such as JSON, YAML, Pickle, etc.
 serde = { version = "1", optional = true }
 
+[features]
+default = []
+# Used solely to enable docs generate with docs.rs that does not have a ROS installation
+generate_docs = []
+
 [dev-dependencies]
 # Needed for writing property tests
 quickcheck = "1"
 # Needed for testing serde support
 serde_json = "1"
+
+[build-dependencies]
+# Needed for uploading documentation to docs.rs
+cfg-if = "1.0.0"
+
+[package.metadata.docs.rs]
+features = ["generate_docs"]

rosidl_runtime_rs/build.rs

@@ -1,24 +1,31 @@
-use std::env;
-use std::path::Path;
+cfg_if::cfg_if! {
+    if #[cfg(not(feature="generate_docs"))] {
+        use std::env;
+        use std::path::Path;
 
-const AMENT_PREFIX_PATH: &str = "AMENT_PREFIX_PATH";
+        const AMENT_PREFIX_PATH: &str = "AMENT_PREFIX_PATH";
 
-fn get_env_var_or_abort(env_var: &'static str) -> String {
-    if let Ok(value) = env::var(env_var) {
-        value
-    } else {
-        panic!(
-            "{} environment variable not set - please source ROS 2 installation first.",
-            env_var
-        );
+        fn get_env_var_or_abort(env_var: &'static str) -> String {
+            if let Ok(value) = env::var(env_var) {
+                value
+            } else {
+                panic!(
+                    "{} environment variable not set - please source ROS 2 installation first.",
+                    env_var
+                );
+            }
+        }
     }
 }
 
 fn main() {
-    let ament_prefix_path_list = get_env_var_or_abort(AMENT_PREFIX_PATH);
-    for ament_prefix_path in ament_prefix_path_list.split(':') {
-        let library_path = Path::new(ament_prefix_path).join("lib");
-        println!("cargo:rustc-link-search=native={}", library_path.display());
+    #[cfg(not(feature = "generate_docs"))]
+    {
+        let ament_prefix_path_list = get_env_var_or_abort(AMENT_PREFIX_PATH);
+        for ament_prefix_path in ament_prefix_path_list.split(':') {
+            let library_path = Path::new(ament_prefix_path).join("lib");
+            println!("cargo:rustc-link-search=native={}", library_path.display());
+        }
     }
 
     // Invalidate the built crate whenever this script changes