Some command line argument parsing with clap

rust/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+clap = { version = "4.1.1", features = ["cargo"] }

rust/src/cli.rs

@@ -0,0 +1,76 @@
+use clap::{arg, crate_version, Command};
+
+/// Create the [command](clap::Command) object which will handle all of the command line arguments. 
+pub fn make_cli() -> Command {
+    Command::new("tockloader")
+        .about("This is a sample description.")
+        .version(crate_version!())
+        .arg_required_else_help(true)
+        .subcommands(get_subcommands())
+        .args([
+            arg!(--debug "Print additional debugging information").action(clap::ArgAction::SetTrue)
+        ])
+    // Note: arg_require_else_help will trigger the help command if no argument/subcommand is given.
+    // This means that the --debug flag will not trigger the help menu, even if alone it does nothing.
+}
+
+/// Generate all of the [subcommands](clap::Command) used by the program.
+fn get_subcommands() -> Vec<Command> {
+    vec![Command::new("listen")
+        .about("Open a terminal to receive UART data")
+        .args(get_app_args())
+        .args(get_channel_args())
+        .arg_required_else_help(true)]
+}
+
+/// Generate all of the [arguments](clap::Arg) that are required by subcommands which work with apps.
+fn get_app_args() -> Vec<clap::Arg> {
+    vec![
+        arg!(-a --"app-address" <ADDRESS> "Address where apps are located"),
+        arg!(--force "Allow apps on boards that are not listed as compatible")
+            .action(clap::ArgAction::SetTrue),
+        arg!(--"bundle-apps" "Concatenate apps and flash all together, re-flashing apps as needed")
+            .action(clap::ArgAction::SetTrue),
+    ]
+    // Note: the .action(clap::ArgAction::SetTrue) doesn't seem to be necessary, though in clap documentation it is used.
+}
+
+/// Generate all of the [arguments](clap::Arg) that are required by subcommands which work
+/// with channels and computer-board communication.
+fn get_channel_args() -> Vec<clap::Arg> {
+    vec![
+        arg!(-p --port "The serial port or device name to use"),
+        arg!(--serial "Use the serial bootloader to flash")
+            .action(clap::ArgAction::SetTrue),
+        // Should we include depracated functionality?
+        // Other deprecated arguments are not included here, just this one.
+        /* arg!(--jtag "Use JTAG and JLinkExe to flash. Deprecated. Use --jlink instead")
+            .action(clap::ArgAction::SetTrue), */
+        arg!(--jlink "Use JLinkExe to flash")
+            .action(clap::ArgAction::SetTrue),
+        arg!(--openocd "Use OpenOCD to flash")
+            .action(clap::ArgAction::SetTrue),
+        arg!(--"jlink-device" <DEVICE> "The device type to pass to JLinkExe. Useful for initial commissioning.")
+            .default_value("cortex-m0"),
+        arg!(--"jlink-cmd" <CMD> "The JLinkExe binary to invoke"),
+        arg!(--"jlink-speed" <SPEED> "The JLink speed to pass to JLinkExe"),
+        arg!(--"jlink-if" <INTERFACE> "The interface type to pass to JLinkExe"),
+        arg!(--"openocd-board" <CFG_FILE> "The cfg file in OpenOCD `board` folder"),
+        arg!(--"openocd-cmd" <CMD> "The openocd binary to invoke")
+            .default_value("openocd"),
+        // These may not work out of the box
+        arg!(--"openocd-options" <OPTIONS> "Tockloader-specific flags to direct how Tockloader uses OpenOCD"),
+        arg!(--"openocd-commands" <CMDS> "Directly specify which OpenOCD commands to use for \"program\", \"read\", or \"erase\" actions"),
+        // -----
+        arg!(--"flash-file" "Operate on a binary flash file instead of a proper board")
+            .action(clap::ArgAction::SetTrue),
+        arg!(--board <BOARD> "Explicitly specify the board that is being targeted"),
+        arg!(--arch <ARCH> "Explicitly specify the architecture of the board that is being targeted"),
+        arg!(--"page-size" <SIZE> "Explicitly specify how many bytes in a flash page")
+            .default_value("0"),
+        arg!(--"baud-rate" <RATE> "If using serial, set the target baud rate")
+            .default_value("115200"),
+        arg!(--"no-bootloader-entry" "Tell Tockloader to assume the bootloader is already active")
+            .action(clap::ArgAction::SetTrue),
+    ]
+}

rust/src/main.rs

@@ -1,3 +1,27 @@
+mod cli;
+use cli::make_cli;
+
 fn main() {
-    println!("Hello, world!");
+    let matches = make_cli().get_matches();
+
+    if matches.get_flag("debug") {
+        println!("Debug mode enabled");
+    }
+
+    match matches.subcommand() {
+        Some(("listen", sub_matches)) => {
+            println!("Got the listen subcommand");
+            let default_adr = "NONE".to_string();
+            let adr = sub_matches
+                .get_one::<String>("app-address")
+                .unwrap_or(&default_adr);
+            println!("{}", format!("With App Address {adr}"));
+        }
+        // If only the "--debug" flag is set, then this branch is executed
+        // Or, more likely at this stage, a subcommand hasn't been implemented yet.
+        _ => {
+            println!("Could not run the provided subcommand.");
+            _ = make_cli().print_help();
+        }
+    }
 }