Checkpoint for gRPC implementation

examples/hello_world/build.rs

@@ -0,0 +1,27 @@
+fn main() {
+    let proto_file = "proto/hello.proto";
+    let out_dir = std::env::var("OUT_DIR").unwrap();
+    let dest_path = std::path::Path::new(&out_dir).join("hello.rs");
+
+    // Find the protoc-gen-roto binary
+    // In a real scenario, this should be passed as an environment variable or found in PATH
+    // For this example, we'll try to find it in the target directory
+    let target_dir = std::env::current_dir().unwrap().join("../../target/debug");
+    let plugin_path = target_dir.join("protoc-gen-roto");
+
+    if !plugin_path.exists() {
+        panic!("protoc-gen-roto plugin not found at {:?}", plugin_path);
+    }
+
+    let status = std::process::Command::new("protoc")
+        .arg(format!("--plugin=protoc-gen-roto={}", plugin_path.display()))
+        .arg(format!("--roto_out={}", out_dir))
+        .arg(format!("--roto_opt=src=proto")) // Assuming the plugin handles this or we just pass it
+        .arg(proto_file)
+        .status()
+        .expect("Failed to execute protoc");
+
+    if !status.success() {
+        panic!("protoc failed with status {}", status);
+    }
+}