Fix a bunch of clippy lints in the build system

Author: bjorn3

build_system/bench.rs

@@ -144,7 +144,7 @@ fn hyperfine_command(
     }
 
     for &(name, cmd) in cmds {
-        if name != "" {
+        if !name.is_empty() {
             bench.arg("-n").arg(name);
         }
         bench.arg(cmd);

build_system/build_backend.rs

@@ -16,7 +16,7 @@ pub(crate) fn build_backend(
 ) -> PathBuf {
     let _group = LogGroup::guard("Build backend");
 
-    let mut cmd = CG_CLIF.build(&bootstrap_host_compiler, dirs);
+    let mut cmd = CG_CLIF.build(bootstrap_host_compiler, dirs);
 
     let mut rustflags = rustflags_from_env("RUSTFLAGS");
     rustflags.push("-Zallow-features=rustc_private,f16,f128".to_owned());

build_system/build_sysroot.rs

@@ -49,7 +49,7 @@ pub(crate) fn build_sysroot(
         let mut build_cargo_wrapper_cmd = Command::new(&bootstrap_host_compiler.rustc);
         let wrapper_path = dist_dir.join(&wrapper_name);
         build_cargo_wrapper_cmd
-            .arg(dirs.source_dir.join("scripts").join(&format!("{wrapper}.rs")))
+            .arg(dirs.source_dir.join("scripts").join(format!("{wrapper}.rs")))
             .arg("-o")
             .arg(&wrapper_path)
             .arg("-Cstrip=debuginfo");

build_system/rustc_info.rs

@@ -4,7 +4,7 @@ use std::process::{Command, Stdio};
 pub(crate) fn get_host_triple(rustc: &Path) -> String {
     let version_info = Command::new(rustc)
         .stderr(Stdio::inherit())
-        .args(&["--print", "host-tuple"])
+        .args(["--print", "host-tuple"])
         .output()
         .unwrap()
         .stdout;
@@ -14,7 +14,7 @@ pub(crate) fn get_host_triple(rustc: &Path) -> String {
 pub(crate) fn get_toolchain_name() -> String {
     let active_toolchain = Command::new("rustup")
         .stderr(Stdio::inherit())
-        .args(&["show", "active-toolchain"])
+        .args(["show", "active-toolchain"])
         .output()
         .unwrap()
         .stdout;
@@ -27,7 +27,7 @@ pub(crate) fn get_cargo_path() -> PathBuf {
     }
     let cargo_path = Command::new("rustup")
         .stderr(Stdio::inherit())
-        .args(&["which", "cargo"])
+        .args(["which", "cargo"])
         .output()
         .unwrap()
         .stdout;
@@ -40,7 +40,7 @@ pub(crate) fn get_rustc_path() -> PathBuf {
     }
     let rustc_path = Command::new("rustup")
         .stderr(Stdio::inherit())
-        .args(&["which", "rustc"])
+        .args(["which", "rustc"])
         .output()
         .unwrap()
         .stdout;
@@ -53,7 +53,7 @@ pub(crate) fn get_rustdoc_path() -> PathBuf {
     }
     let rustc_path = Command::new("rustup")
         .stderr(Stdio::inherit())
-        .args(&["which", "rustdoc"])
+        .args(["which", "rustdoc"])
         .output()
         .unwrap()
         .stdout;
@@ -63,7 +63,7 @@ pub(crate) fn get_rustdoc_path() -> PathBuf {
 pub(crate) fn get_default_sysroot(rustc: &Path) -> PathBuf {
     let default_sysroot = Command::new(rustc)
         .stderr(Stdio::inherit())
-        .args(&["--print", "sysroot"])
+        .args(["--print", "sysroot"])
         .output()
         .unwrap()
         .stdout;
@@ -74,7 +74,7 @@ pub(crate) fn get_default_sysroot(rustc: &Path) -> PathBuf {
 pub(crate) fn get_file_name(rustc: &Path, crate_name: &str, crate_type: &str) -> String {
     let file_name = Command::new(rustc)
         .stderr(Stdio::inherit())
-        .args(&[
+        .args([
             "--crate-name",
             crate_name,
             "--crate-type",

build_system/tests.rs

@@ -355,7 +355,7 @@ impl<'a> TestRunner<'a> {
 
             let _guard = if !config::get_bool(config)
                 || (is_jit_test && !self.jit_supported)
-                || self.skip_tests.contains(&config)
+                || self.skip_tests.contains(config)
             {
                 eprintln!("[{tag}] {testname} (skipped)");
                 continue;

build_system/utils.rs

@@ -162,7 +162,7 @@ impl CargoProject {
 pub(crate) fn try_hard_link(src: impl AsRef<Path>, dst: impl AsRef<Path>) {
     let src = src.as_ref();
     let dst = dst.as_ref();
-    if let Err(_) = fs::hard_link(src, dst) {
+    if fs::hard_link(src, dst).is_err() {
         fs::copy(src, dst).unwrap(); // Fallback to copying if hardlinking failed
     }
 }
@@ -179,7 +179,7 @@ pub(crate) fn spawn_and_wait(mut cmd: Command) {
 /// Create the specified directory if it doesn't exist yet and delete all contents.
 pub(crate) fn ensure_empty_dir(path: &Path) {
     fs::create_dir_all(path).unwrap();
-    let read_dir = match fs::read_dir(&path) {
+    let read_dir = match fs::read_dir(path) {
         Ok(read_dir) => read_dir,
         Err(err) if err.kind() == io::ErrorKind::NotFound => {
             return;