feat: add new cli flag --fair-sched and support for experimental flags

Author: GuillaumeLagrange

src/cli/experimental.rs

@@ -0,0 +1,48 @@
+use crate::local_logger::icons::Icon;
+use clap::Args;
+use console::style;
+
+/// Experimental flags that may change or be removed without notice.
+///
+/// These flags are under active development and their behavior is not guaranteed
+/// to remain stable across releases.
+#[derive(Args, Debug, Clone)]
+pub struct ExperimentalArgs {
+    /// Enable valgrind's --fair-sched option.
+    #[arg(long, default_value_t = false, help_heading = "Experimental")]
+    pub fair_sched: bool,
+}
+
+impl ExperimentalArgs {
+    /// Returns the names of all experimental flags that were explicitly set by the user.
+    pub fn active_flags(&self) -> Vec<&'static str> {
+        let mut flags = Vec::new();
+        if self.fair_sched {
+            flags.push("--fair-sched");
+        }
+        flags
+    }
+
+    /// If any experimental flags are active, prints a warning to stderr.
+    pub fn warn_if_active(&self) {
+        let flags = self.active_flags();
+        if flags.is_empty() {
+            return;
+        }
+
+        let flag_list = flags
+            .iter()
+            .map(|f| style(*f).bold().to_string())
+            .collect::<Vec<_>>()
+            .join(", ");
+
+        eprintln!(
+            "\n  {} Experimental flags enabled: {}\n  \
+            These may change or be removed without notice.\n  \
+            Share feedback at {}.\n",
+            style(Icon::Warning.to_string()).yellow(),
+            flag_list,
+            style("https://github.com/CodSpeedHQ/codspeed/issues").underlined(),
+        );
+    }
+}

src/cli/mod.rs

@@ -1,5 +1,6 @@
 mod auth;
 pub(crate) mod exec;
+pub(crate) mod experimental;
 pub(crate) mod run;
 mod setup;
 mod shared;
@@ -148,6 +149,7 @@ pub async fn run() -> Result<()> {
 
     match cli.command {
         Commands::Run(args) => {
+            args.shared.experimental.warn_if_active();
             run::run(
                 *args,
                 &api_client,
@@ -158,6 +160,7 @@ pub async fn run() -> Result<()> {
             .await?
         }
         Commands::Exec(args) => {
+            args.shared.experimental.warn_if_active();
             exec::run(
                 *args,
                 &api_client,

src/cli/run/mod.rs

@@ -49,6 +49,7 @@ impl RunArgs {
     /// Constructs a new `RunArgs` with default values for testing purposes
     pub fn test() -> Self {
         use super::PerfRunArgs;
+        use super::experimental::ExperimentalArgs;
         use crate::RunnerMode;
 
         Self {
@@ -72,6 +73,7 @@ impl RunArgs {
                     enable_perf: false,
                     perf_unwinding_mode: None,
                 },
+                experimental: ExperimentalArgs { fair_sched: false },
             },
             instruments: vec![],
             mongo_uri_env_name: None,

src/cli/shared.rs

@@ -1,3 +1,4 @@
+use super::experimental::ExperimentalArgs;
 use crate::VERSION;
 use crate::executor::config::SimulationTool;
 use crate::local_logger::CODSPEED_U8_COLOR_CODE;
@@ -116,6 +117,9 @@ pub struct ExecAndRunSharedArgs {
 
     #[command(flatten)]
     pub perf_run_args: PerfRunArgs,
+
+    #[command(flatten)]
+    pub experimental: ExperimentalArgs,
 }
 
 impl ExecAndRunSharedArgs {