ROS_DISTRO as configuration option.

Allows us to handle API differences between ros versions.

r2r/build.rs

@@ -17,6 +17,7 @@ const GENERATED_FILES: &[&str] = &[
 
 fn main() {
     r2r_common::print_cargo_watches();
+    r2r_common::print_cargo_ros_distro();
 
     let env_hash = r2r_common::get_env_hash();
     let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());

r2r/examples/parameters.rs

@@ -10,6 +10,8 @@ use futures::task::LocalSpawnExt;
 // ros2 param get /demo/my_node key2 # (should return false)
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("Ros version: {}", r2r::ROS_DISTRO);
+
     // set up executor
     let mut pool = LocalPool::new();
     let spawner = pool.spawner();

r2r/src/lib.rs

@@ -122,3 +122,16 @@ pub use nodes::{Node, Timer};
 
 pub mod qos;
 pub use qos::QosProfile;
+
+/// The ros version currently built against.
+#[cfg(r2r__ros__distro__foxy)]
+pub const ROS_DISTRO: &str = "foxy";
+#[cfg(r2r__ros__distro__galactic)]
+pub const ROS_DISTRO: &str = "galactic";
+#[cfg(r2r__ros__distro__humble)]
+pub const ROS_DISTRO: &str = "humble";
+#[cfg(r2r__ros__distro__rolling)]
+pub const ROS_DISTRO: &str = "rolling";
+#[cfg(not(any(r2r__ros__distro__foxy, r2r__ros__distro__galactic,
+              r2r__ros__distro__humble, r2r__ros__distro__rolling)))]
+pub const ROS_DISTRO: &str = "unknown";

r2r_actions/build.rs

@@ -6,6 +6,7 @@ const BINDINGS_FILENAME: &str = "action_bindings.rs";
 
 fn main() {
     r2r_common::print_cargo_watches();
+    r2r_common::print_cargo_ros_distro();
 
     run_bindgen();
     run_dynlink();

r2r_common/src/lib.rs

@@ -6,12 +6,20 @@ use std::fs::{self, File};
 use std::io::Read;
 use std::path::Path;
 
+const SUPPORTED_ROS_DISTROS: &[&str] = &[
+    "foxy",
+    "galactic",
+    "humble",
+    "rolling",
+];
+
 const WATCHED_ENV_VARS: &[&str] = &[
     "AMENT_PREFIX_PATH",
     "CMAKE_INCLUDE_DIRS",
     "CMAKE_LIBRARIES",
     "CMAKE_IDL_PACKAGES",
     "IDL_PACKAGE_FILTER",
+    "ROS_DISTRO",
 ];
 
 pub fn get_env_hash() -> String {
@@ -111,6 +119,17 @@ pub fn setup_bindgen_builder() -> bindgen::Builder {
     builder
 }
 
+pub fn print_cargo_ros_distro() {
+    let ros_distro = env::var("ROS_DISTRO")
+        .unwrap_or_else(|_| panic!("ROS_DISTRO not set: Source your ROS!"));
+
+    if SUPPORTED_ROS_DISTROS.iter().any(|d| d == &ros_distro) {
+        println!("cargo:rustc-cfg=r2r__ros__distro__{ros_distro}");
+    } else {
+        panic!("ROS_DISTRO not supported: {ros_distro}");
+    }
+}
+
 pub fn print_cargo_link_search() {
     if env::var("CMAKE_INCLUDE_DIRS").is_ok() {
         if let Ok(paths) = env::var("CMAKE_LIBRARIES") {

r2r_msg_gen/build.rs

@@ -19,6 +19,7 @@ const GENERATED_FILES: &[&str] = &[
 
 fn main() {
     r2r_common::print_cargo_watches();
+    r2r_common::print_cargo_ros_distro();
 
     let msg_list = r2r_common::get_wanted_messages();
     run_bindgen(&msg_list);

r2r_rcl/build.rs

@@ -6,6 +6,7 @@ use std::path::PathBuf;
 
 fn main() {
     r2r_common::print_cargo_watches();
+    r2r_common::print_cargo_ros_distro();
     run_bindgen();
     run_dynlink();
 }