Fix building without systemd + minor clippy

Some of the feature gates were out of date for builds precluding
systemd, logind, or both. I also cleaned up the systemd/logind gates in
general as well as fixed a few very minor clippy lints.

src/main.rs

@@ -7,6 +7,7 @@ mod comp;
 mod notifications;
 mod process;
 mod service;
+#[cfg(feature = "systemd")]
 mod systemd;
 
 use color_eyre::Result;
@@ -15,18 +16,13 @@ use launch_pad::ProcessManager;
 use launch_pad::process::Process;
 use service::SessionRequest;
 use std::borrow::Cow;
-#[cfg(feature = "autostart")]
-use std::collections::HashSet;
 use std::env;
 use std::os::fd::AsRawFd;
-#[cfg(feature = "autostart")]
-use std::path::PathBuf;
-#[cfg(feature = "autostart")]
-use std::process::{Command, Stdio};
 use std::sync::Arc;
+#[cfg(any(feature = "autostart", feature = "systemd"))]
+use std::{path::Path, sync::OnceLock};
 #[cfg(feature = "systemd")]
-use systemd::spawn_scope;
-use systemd::{get_systemd_env, is_systemd_used};
+use systemd::{get_systemd_env, spawn_scope};
 use tokio::signal::unix::{SignalKind, signal};
 use tokio::sync::mpsc::{Receiver, Sender};
 use tokio::sync::{Mutex, oneshot};
@@ -36,14 +32,20 @@ use tracing::Instrument;
 use tracing::metadata::LevelFilter;
 use tracing_subscriber::prelude::*;
 use tracing_subscriber::{EnvFilter, fmt};
+#[cfg(feature = "autostart")]
+use {
+	std::collections::HashSet,
+	std::path::PathBuf,
+	std::process::{Command, Stdio},
+};
 
 use crate::notifications::{
 	DAEMON_NOTIFICATIONS_FD, PANEL_NOTIFICATIONS_FD, notifications_process,
 };
 #[cfg(feature = "autostart")]
-const AUTOSTART_DIR: &'static str = "autostart";
+const AUTOSTART_DIR: &str = "autostart";
 #[cfg(feature = "autostart")]
-const ENVIRONMENT_NAME: &'static str = "COSMIC";
+const ENVIRONMENT_NAME: &str = "COSMIC";
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<()> {
@@ -143,7 +145,15 @@ async fn start(
 		.await;
 	let token = CancellationToken::new();
 	let (env_tx, env_rx) = oneshot::channel();
-	let systemd_env = get_systemd_env().await;
+
+	#[cfg(feature = "systemd")]
+	let systemd_env = if *is_systemd_used() {
+		get_systemd_env().await
+	} else {
+		Vec::new()
+	};
+	#[cfg(not(feature = "systemd"))]
+	let systemd_env = Vec::new();
 	let compositor_handle = comp::run_compositor(
 		&process_manager,
 		executable.clone(),
@@ -165,12 +175,13 @@ async fn start(
 		env_vars
 	);
 
-	// now that cosmic-comp is ready, extend the env vars with the systemd_env and set XDG_SESSION_TYPE=wayland for new processes
+	// now that cosmic-comp is ready, set XDG_SESSION_TYPE=wayland for new processes
 	env_vars.extend(
 		systemd_env
 			.into_iter()
 			.chain([("XDG_SESSION_TYPE".to_string(), "wayland".to_string())]),
 	);
+	#[cfg(feature = "systemd")]
 	systemd::set_systemd_environment("XDG_SESSION_TYPE", "wayland").await;
 
 	// expose the session version
@@ -178,42 +189,36 @@ async fn start(
 		"COSMIC_VERSION".to_string(),
 		env!("CARGO_PKG_VERSION").to_string(),
 	));
+	#[cfg(feature = "systemd")]
 	systemd::set_systemd_environment("COSMIC_VERSION", env!("CARGO_PKG_VERSION")).await;
 
-	#[cfg(feature = "systemd")]
-	let _inhibit_fd = if *is_systemd_used() {
-		#[cfg(feature = "logind")]
-		match zbus::Connection::system().await {
-			Ok(connection) => match logind_zbus::manager::ManagerProxy::new(&connection).await {
-				Ok(proxy) => match proxy
-					.inhibit(
-						logind_zbus::manager::InhibitType::HandlePowerKey,
-						"Cosmic Session",
-						"Show confirmation dialog.",
-						"block",
-					)
-					.await
-				{
-					Ok(fd) => Some(fd),
-					Err(err) => {
-						error!("Failed to inhibit power key {err:?}");
-						None
-					}
-				},
+	#[cfg(feature = "logind")]
+	let _inhibit_fd = match zbus::Connection::system().await {
+		Ok(connection) => match logind_zbus::manager::ManagerProxy::new(&connection).await {
+			Ok(proxy) => match proxy
+				.inhibit(
+					logind_zbus::manager::InhibitType::HandlePowerKey,
+					"Cosmic Session",
+					"Show confirmation dialog.",
+					"block",
+				)
+				.await
+			{
+				Ok(fd) => Some(fd),
 				Err(err) => {
-					error!("Failed to connect to logind manager {err:?}");
+					error!("Failed to inhibit power key {err:?}");
 					None
 				}
 			},
 			Err(err) => {
-				error!("Failed to connect to system dbus {err:?}");
+				error!("Failed to connect to logind manager {err:?}");
 				None
 			}
+		},
+		Err(err) => {
+			error!("Failed to connect to system dbus {err:?}");
+			None
 		}
-		#[cfg(not(feature = "logind"))]
-		None
-	} else {
-		None
 	};
 
 	let stdout_span = info_span!(parent: None, "cosmic-settings-daemon");
@@ -254,8 +259,10 @@ async fn start(
 	// - cosmic-comp is ready
 	// - we've set any related variables
 	// - cosmic-settings-daemon is ready
+	#[cfg(feature = "systemd")]
 	systemd::start_systemd_target().await;
 	// Always stop the target when the process exits or panics.
+	#[cfg(feature = "systemd")]
 	scopeguard::defer! {
 		systemd::stop_systemd_target();
 	}
@@ -388,17 +395,17 @@ async fn start(
 			}
 
 			// skip if we have an OnlyShowIn entry that doesn't include COSMIC
-			if let Some(only_show_in) = entry.only_show_in() {
-				if !only_show_in.contains(&ENVIRONMENT_NAME) {
-					continue;
-				}
+			if let Some(only_show_in) = entry.only_show_in()
+				&& !only_show_in.contains(&ENVIRONMENT_NAME)
+			{
+				continue;
 			}
 
 			// ... OR we have a NotShowIn entry that includes COSMIC
-			if let Some(not_show_in) = entry.not_show_in() {
-				if not_show_in.contains(&ENVIRONMENT_NAME) {
-					continue;
-				}
+			if let Some(not_show_in) = entry.not_show_in()
+				&& not_show_in.contains(&ENVIRONMENT_NAME)
+			{
+				continue;
 			}
 
 			info!(
@@ -417,7 +424,7 @@ async fn start(
 						.collect::<Vec<_>>();
 
 					// escape them
-					let escaped_args = shell_words::split(&*filtered_args.join(" "));
+					let escaped_args = shell_words::split(&filtered_args.join(" "));
 					if let Ok(args) = escaped_args {
 						info!("trying to start {} {}", program_name, args.join(" "));
 
@@ -556,3 +563,11 @@ async fn start_component(
 		error!("failed to start {}: {}", cmd, err);
 	}
 }
+
+/// Determine if systemd is used as the init system. This should work on all
+/// linux distributions.
+#[cfg(any(feature = "autostart", feature = "systemd"))]
+fn is_systemd_used() -> &'static bool {
+	static IS_SYSTEMD_USED: OnceLock<bool> = OnceLock::new();
+	IS_SYSTEMD_USED.get_or_init(|| Path::new("/run/systemd/system").exists())
+}

src/systemd.rs

@@ -1,14 +1,9 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
-use std::path::Path;
 use std::process::{Command, Stdio};
-use std::sync::OnceLock;
 
-#[cfg(feature = "systemd")]
 use zbus::Connection;
 use zbus::zvariant::{Array, OwnedValue};
-
-#[cfg(feature = "systemd")]
 use zbus_systemd::systemd1::ManagerProxy as SystemdManagerProxy;
 
 pub async fn set_systemd_environment(key: &str, value: &str) {
@@ -32,14 +27,6 @@ pub fn stop_systemd_target() {
 	)
 }
 
-/// Determine if systemd is used as the init system. This should work on all
-/// linux distributions.
-pub fn is_systemd_used() -> &'static bool {
-	static IS_SYSTEMD_USED: OnceLock<bool> = OnceLock::new();
-	IS_SYSTEMD_USED.get_or_init(|| Path::new("/run/systemd/system").exists())
-}
-
-#[cfg(feature = "systemd")]
 async fn load_systemd_env() -> zbus::Result<Vec<String>> {
 	let connection = Connection::session().await?;
 	let systemd_manager = SystemdManagerProxy::new(&connection).await?;
@@ -47,18 +34,15 @@ async fn load_systemd_env() -> zbus::Result<Vec<String>> {
 }
 
 /// Get the systemd user manager environment variables.
-/// Is Empty if systemd isn't used.
 pub async fn get_systemd_env() -> Vec<(String, String)> {
-	#[cfg(feature = "systemd")]
-	if *is_systemd_used() {
-		return match load_systemd_env().await {
-			Ok(env) => {
-				env.iter()
-					// split into key value pairs
-					.filter_map(|var| var.split_once("="))
-					.filter(|&(key, _value)| {
-						// Only update the envvar if unset
-						std::env::var_os(key).is_none()
+	match load_systemd_env().await {
+		Ok(env) => {
+			env.iter()
+				// split into key value pairs
+				.filter_map(|var| var.split_once("="))
+				.filter(|&(key, _value)| {
+					// Only update the envvar if unset
+					std::env::var_os(key).is_none()
                               // Blocklist of envvars that we shouldn't touch (taken from KDE)
                               && (!key.starts_with("XDG_")
                                       || key == "XDG_DATA_DIRS"
@@ -70,20 +54,17 @@ pub async fn get_systemd_env() -> Vec<(String, String)> {
                               && key != "_"
                               && key != "SHELL"
                               && key != "SHLVL"
-					})
-					.map(|(key, value)| (key.to_owned(), value.to_owned()))
-					.collect()
-			}
-			Err(err) => {
-				warn!("Failed to sync systemd environment {}.", err);
-				Vec::new()
-			}
-		};
+				})
+				.map(|(key, value)| (key.to_owned(), value.to_owned()))
+				.collect()
+		}
+		Err(err) => {
+			warn!("Failed to sync systemd environment {}.", err);
+			Vec::new()
+		}
 	}
-	Vec::new()
 }
 
-#[cfg(feature = "systemd")]
 /// Spawn a systemd scope unit with the given name and PIDs.
 pub async fn spawn_scope(mut command: String, pids: Vec<u32>) -> Result<(), zbus::Error> {
 	let connection = Connection::session().await?;