ptest: Add command line parsing

Add a skeleton of a command line parser to the ptest utility.  This will allow
future changes to add additional options, such as listing and filtering the
tests that are used.

This adds a single subcommand `run`, which mimics the previous ptest behavior.

Signed-off-by: David Brown <david.brown@linaro.org>

Author: d3zd3z

ptest/Cargo.lock

@@ -12,3 +12,7 @@ log = "0.4.17"
 num_cpus = "1.13.1"
 std-semaphore = "0.1"
 yaml-rust = "0.4"
+
+[dependencies.clap]
+version = "4.0"
+features = ["derive"]

ptest/Cargo.toml

@@ -11,6 +11,7 @@
 //! jobs->environment->strategy->matric->features
 
 use chrono::Local;
+use clap::{Parser, Subcommand};
 use log::{debug, error, warn};
 use std::{
     collections::HashSet,
@@ -37,6 +38,12 @@ type Result<T> = result::Result<T, failure::Error>;
 fn main() -> Result<()> {
     env_logger::init();
 
+    let args = Cli::parse();
+
+    match args.command {
+        Commands::Run => (),
+    }
+
     let workflow_text = fs::read_to_string("../.github/workflows/sim.yaml")?;
     let workflow = YamlLoader::load_from_str(&workflow_text)?;
 
@@ -76,6 +83,21 @@ fn main() -> Result<()> {
     Ok(())
 }
 
+/// The main Cli.
+#[derive(Debug, Parser)]
+#[command(name = "ptest")]
+#[command(about = "Run MCUboot CI tests stand alone")]
+struct Cli {
+    #[command(subcommand)]
+    command: Commands,
+}
+
+#[derive(Debug, Subcommand)]
+enum Commands {
+    /// Runs the tests.
+    Run,
+}
+
 /// State, for printing status.
 struct State {
     running: HashSet<String>,