run-make-support: add #[must_use] annotations

Author: jieyouxu

src/tools/run-make-support/src/cc.rs

@@ -15,6 +15,7 @@ pub fn cc() -> Cc {
 /// A platform-specific C compiler invocation builder. The specific C compiler used is
 /// passed down from compiletest.
 #[derive(Debug)]
+#[must_use]
 pub struct Cc {
     cmd: Command,
 }

src/tools/run-make-support/src/clang.rs

@@ -11,6 +11,7 @@ pub fn clang() -> Clang {
 
 /// A `clang` invocation builder.
 #[derive(Debug)]
+#[must_use]
 pub struct Clang {
     cmd: Command,
 }

src/tools/run-make-support/src/command.rs

@@ -149,14 +149,17 @@ pub struct CompletedProcess {
 }
 
 impl CompletedProcess {
+    #[must_use]
     pub fn stdout_utf8(&self) -> String {
         String::from_utf8(self.output.stdout.clone()).expect("stdout is not valid UTF-8")
     }
 
+    #[must_use]
     pub fn stderr_utf8(&self) -> String {
         String::from_utf8(self.output.stderr.clone()).expect("stderr is not valid UTF-8")
     }
 
+    #[must_use]
     pub fn status(&self) -> ExitStatus {
         self.output.status
     }

src/tools/run-make-support/src/diff/mod.rs

@@ -13,6 +13,7 @@ pub fn diff() -> Diff {
 }
 
 #[derive(Debug)]
+#[must_use]
 pub struct Diff {
     expected: Option<String>,
     expected_name: Option<String>,

src/tools/run-make-support/src/lib.rs

@@ -34,6 +34,7 @@ pub use rustc::{aux_build, rustc, Rustc};
 pub use rustdoc::{bare_rustdoc, rustdoc, Rustdoc};
 
 #[track_caller]
+#[must_use]
 pub fn env_var(name: &str) -> String {
     match env::var(name) {
         Ok(v) => v,
@@ -42,6 +43,7 @@ pub fn env_var(name: &str) -> String {
 }
 
 #[track_caller]
+#[must_use]
 pub fn env_var_os(name: &str) -> OsString {
     match env::var_os(name) {
         Some(v) => v,
@@ -50,44 +52,52 @@ pub fn env_var_os(name: &str) -> OsString {
 }
 
 /// `TARGET`
+#[must_use]
 pub fn target() -> String {
     env_var("TARGET")
 }
 
 /// Check if target is windows-like.
+#[must_use]
 pub fn is_windows() -> bool {
     target().contains("windows")
 }
 
 /// Check if target uses msvc.
+#[must_use]
 pub fn is_msvc() -> bool {
     target().contains("msvc")
 }
 
 /// Check if target uses macOS.
+#[must_use]
 pub fn is_darwin() -> bool {
     target().contains("darwin")
 }
 
 #[track_caller]
+#[must_use]
 pub fn python_command() -> Command {
     let python_path = env_var("PYTHON");
     Command::new(python_path)
 }
 
 #[track_caller]
+#[must_use]
 pub fn htmldocck() -> Command {
     let mut python = python_command();
     python.arg(source_root().join("src/etc/htmldocck.py"));
     python
 }
 
 /// Path to the root rust-lang/rust source checkout.
+#[must_use]
 pub fn source_root() -> PathBuf {
     env_var("SOURCE_ROOT").into()
 }
 
 /// Construct the static library name based on the platform.
+#[must_use]
 pub fn static_lib_name(name: &str) -> String {
     // See tools.mk (irrelevant lines omitted):
     //
@@ -112,6 +122,7 @@ pub fn static_lib_name(name: &str) -> String {
 }
 
 /// Construct the dynamic library name based on the platform.
+#[must_use]
 pub fn dynamic_lib_name(name: &str) -> String {
     // See tools.mk (irrelevant lines omitted):
     //
@@ -138,6 +149,7 @@ pub fn dynamic_lib_name(name: &str) -> String {
     }
 }
 
+#[must_use]
 pub fn dynamic_lib_extension() -> &'static str {
     if is_darwin() {
         "dylib"
@@ -149,23 +161,27 @@ pub fn dynamic_lib_extension() -> &'static str {
 }
 
 /// Construct a rust library (rlib) name.
+#[must_use]
 pub fn rust_lib_name(name: &str) -> String {
     format!("lib{name}.rlib")
 }
 
 /// Construct the binary name based on platform.
+#[must_use]
 pub fn bin_name(name: &str) -> String {
     if is_windows() { format!("{name}.exe") } else { name.to_string() }
 }
 
 /// Return the current working directory.
+#[must_use]
 pub fn cwd() -> PathBuf {
     env::current_dir().unwrap()
 }
 
 /// Use `cygpath -w` on a path to get a Windows path string back. This assumes that `cygpath` is
 /// available on the platform!
 #[track_caller]
+#[must_use]
 pub fn cygpath_windows<P: AsRef<Path>>(path: P) -> String {
     let caller = panic::Location::caller();
     let mut cygpath = Command::new("cygpath");
@@ -181,6 +197,7 @@ pub fn cygpath_windows<P: AsRef<Path>>(path: P) -> String {
 
 /// Run `uname`. This assumes that `uname` is available on the platform!
 #[track_caller]
+#[must_use]
 pub fn uname() -> String {
     let caller = panic::Location::caller();
     let mut uname = Command::new("uname");

src/tools/run-make-support/src/llvm_readobj.rs

@@ -12,6 +12,7 @@ pub fn llvm_readobj() -> LlvmReadobj {
 
 /// A `llvm-readobj` invocation builder.
 #[derive(Debug)]
+#[must_use]
 pub struct LlvmReadobj {
     cmd: Command,
 }

src/tools/run-make-support/src/rustc.rs

@@ -18,6 +18,7 @@ pub fn aux_build() -> Rustc {
 
 /// A `rustc` invocation builder.
 #[derive(Debug)]
+#[must_use]
 pub struct Rustc {
     cmd: Command,
 }

src/tools/run-make-support/src/rustdoc.rs

@@ -16,6 +16,7 @@ pub fn rustdoc() -> Rustdoc {
 }
 
 #[derive(Debug)]
+#[must_use]
 pub struct Rustdoc {
     cmd: Command,
 }