[hermes] Add package/target/root resolution

tools/hermes/Cargo.toml

@@ -7,6 +7,10 @@ license.workspace = true
 publish.workspace = true
 
 [dependencies]
+anyhow = "1.0.101"
+cargo_metadata = "0.23.1"
+clap = { version = "4.5.57", features = ["derive"] }
+clap-cargo = { version = "0.18.3", features = ["cargo_metadata"] }
 log = "0.4.29"
 miette = { version = "7.6.0", features = ["derive", "fancy"] }
 proc-macro2 = { version = "1.0.105", features = ["span-locations"] }

tools/hermes/src/main.rs

@@ -1,44 +1,55 @@
 mod errors;
 mod parse;
+mod resolve;
 mod transform;
 mod ui_test_shim;
 
-use std::{env, path::PathBuf, process::exit};
+use std::{env, process::exit};
+
+use clap::Parser;
+
+/// Hermes: A Literate Verification Toolchain
+#[derive(Parser, Debug)]
+#[command(name = "hermes", version, about, long_about = None)]
+struct Cli {
+    #[command(flatten)]
+    resolve: resolve::Args,
+}
 
 fn main() {
     if env::var("HERMES_UI_TEST_MODE").is_ok() {
         ui_test_shim::run();
         return;
     }
 
-    let args: Vec<String> = env::args().collect();
-    if args.len() < 2 {
-        eprintln!("Usage: hermes <file.rs>");
-        exit(1);
-    }
+    let args = Cli::parse();
 
-    let file_path = PathBuf::from(&args[1]);
+    // TODO: Better error handling than `.unwrap()`.
+    let roots = resolve::resolve_roots(&args.resolve).unwrap();
 
+    // TODO: From each root, parse and walk referenced modules.
     let mut has_errors = false;
-    let mut edits = Vec::new();
-    let res = parse::read_file_and_visit_hermes_items(&file_path, |_src, res| {
-        if let Err(e) = res {
-            has_errors = true;
-            eprint!("{:?}", miette::Report::new(e));
-        } else if let Ok(item) = res {
-            transform::append_edits(&item, &mut edits);
+    for (package, kind, path) in roots {
+        let mut edits = Vec::new();
+        let res = parse::read_file_and_visit_hermes_items(path.as_std_path(), |_src, res| {
+            if let Err(e) = res {
+                has_errors = true;
+                eprint!("{:?}", miette::Report::new(e));
+            } else if let Ok(item) = res {
+                transform::append_edits(&item, &mut edits);
+            }
+        });
+
+        let source = res.unwrap_or_else(|e| {
+            eprintln!("Error parsing file: {}", e);
+            exit(1);
+        });
+
+        if has_errors {
+            exit(1);
         }
-    });
-
-    let source = res.unwrap_or_else(|e| {
-        eprintln!("Error parsing file: {}", e);
-        exit(1);
-    });
 
-    if has_errors {
-        exit(1);
+        let mut source = source.into_bytes();
+        transform::apply_edits(&mut source, &edits);
     }
-
-    let mut source = source.into_bytes();
-    transform::apply_edits(&mut source, &edits);
 }