inline(always) functions called from bootstrap shims

These functions are called thousands of times during bootstrap,
so it's better to inline them.

Signed-off-by: onur-ozkan <[email protected]>

Author: onur-ozkan

src/bootstrap/src/utils/shared_helpers.rs

@@ -18,6 +18,7 @@ mod tests;
 
 /// Returns the environment variable which the dynamic library lookup path
 /// resides in for this platform.
+#[inline(always)]
 pub fn dylib_path_var() -> &'static str {
     if cfg!(target_os = "windows") {
         "PATH"
@@ -34,6 +35,7 @@ pub fn dylib_path_var() -> &'static str {
 
 /// Parses the `dylib_path_var()` environment variable, returning a list of
 /// paths that are members of this lookup path.
+#[inline(always)]
 pub fn dylib_path() -> Vec<std::path::PathBuf> {
     let var = match std::env::var_os(dylib_path_var()) {
         Some(v) => v,
@@ -44,6 +46,7 @@ pub fn dylib_path() -> Vec<std::path::PathBuf> {
 
 /// Given an executable called `name`, return the filename for the
 /// executable for a particular target.
+#[inline(always)]
 pub fn exe(name: &str, target: &str) -> String {
     if target.contains("windows") {
         format!("{name}.exe")
@@ -60,6 +63,7 @@ pub fn exe(name: &str, target: &str) -> String {
 /// If it was not defined, returns 0 by default.
 ///
 /// Panics if "RUSTC_VERBOSE" is defined with the value that is not an unsigned integer.
+#[inline(always)]
 pub fn parse_rustc_verbose() -> usize {
     match env::var("RUSTC_VERBOSE") {
         Ok(s) => usize::from_str(&s).expect("RUSTC_VERBOSE should be an integer"),
@@ -70,6 +74,7 @@ pub fn parse_rustc_verbose() -> usize {
 /// Parses the value of the "RUSTC_STAGE" environment variable and returns it as a `String`.
 ///
 /// If "RUSTC_STAGE" was not set, the program will be terminated with 101.
+#[inline(always)]
 pub fn parse_rustc_stage() -> String {
     env::var("RUSTC_STAGE").unwrap_or_else(|_| {
         // Don't panic here; it's reasonable to try and run these shims directly. Give a helpful error instead.
@@ -83,6 +88,7 @@ pub fn parse_rustc_stage() -> String {
 ///
 /// Before writing it, replaces user-specific values to create generic dumps for cross-environment
 /// comparisons.
+#[inline(always)]
 pub fn maybe_dump(dump_name: String, cmd: &Command) {
     if let Ok(dump_dir) = env::var("DUMP_BOOTSTRAP_SHIMS") {
         let dump_file = format!("{dump_dir}/{dump_name}");
@@ -98,6 +104,7 @@ pub fn maybe_dump(dump_name: String, cmd: &Command) {
 }
 
 /// Finds `key` and returns its value from the given list of arguments `args`.
+#[inline(always)]
 pub fn parse_value_from_args<'a>(args: &'a [OsString], key: &str) -> Option<&'a str> {
     let mut args = args.iter();
     while let Some(arg) = args.next() {