Roc linker library base setup

linker/src/lib.rs

@@ -0,0 +1,34 @@
+use clap::{App, AppSettings, Arg};
+use std::io;
+
+pub const CMD_PREPROCESS: &str = "preprocess";
+pub const CMD_SURGERY: &str = "surgery";
+pub const EXEC: &str = "EXEC";
+pub const SHARED_LIB: &str = "SHARED_LIB";
+
+pub fn build_app<'a>() -> App<'a> {
+    App::new("link")
+        .about("Preprocesses a platform and surgically links it to an application.")
+        .setting(AppSettings::SubcommandRequiredElseHelp)
+        .subcommand(
+            App::new(CMD_PREPROCESS)
+                .about("Preprocesses a dynamically linked platform to prepare for linking.")
+                .arg(
+                    Arg::with_name(EXEC)
+                        .help("The dynamically link platform executable")
+                        .required(true),
+                )
+                .arg(
+                    Arg::with_name(SHARED_LIB)
+                        .help("The dummy shared library representing the Roc application")
+                        .required(true),
+                ),
+        )
+        .subcommand(
+            App::new(CMD_SURGERY).about("Links a preprocessed platform with a Roc application."),
+        )
+}
+
+pub fn preprocess() -> io::Result<()> {
+    panic!("sad");
+}