Supporting running OSDK commands in workspace root

osdk/src/util.rs

@@ -2,16 +2,19 @@
 
 use std::{
     ffi::OsStr,
+    fs,
     path::{Path, PathBuf},
     process::Command,
 };
 
 use crate::{error::Errno, error_msg};
 
+use quote::ToTokens;
+
 /// FIXME: We should publish the asterinas crates to a public registry
 /// and use the published version in the generated Cargo.toml.
 pub const ASTER_GIT_LINK: &str = "https://github.com/asterinas/asterinas";
-pub const ASTER_GIT_REV: &str = "7d0ea99";
+pub const ASTER_GIT_REV: &str = "437ab80";
 pub fn aster_crate_dep(crate_name: &str) -> String {
     format!(
         "{} = {{ git = \"{}\", rev = \"{}\" }}",
@@ -78,16 +81,90 @@ pub struct CrateInfo {
     pub path: String,
 }
 
+/// Retrieve the default member in the workspace. 
+/// 
+/// If there is only one kernel crate, return that crate; 
+/// If there are multiple kernel crates or no kernel crates in the workspace, 
+/// this function will exit with an error. 
+/// 
+/// A crate is considered a kernel crate if it utilizes the `aster_main` macro.
+fn get_default_member(metadata: &serde_json::Value) -> &str {
+    let default_members = metadata
+        .get("workspace_default_members")
+        .unwrap()
+        .as_array()
+        .unwrap();
+
+    if default_members.len() == 1 {
+        return default_members[0].as_str().unwrap();
+    }
+
+    let packages: Vec<_> = {
+        let packages = metadata.get("packages").unwrap().as_array().unwrap();
+
+        packages
+            .iter()
+            .filter(|package| {
+                let id = package.get("id").unwrap();
+                if !default_members.contains(&id) {
+                    return false;
+                }
+
+                let src_path = {
+                    let targets = package.get("targets").unwrap().as_array().unwrap();
+                    if targets.len() != 1 {
+                        return false;
+                    }
+                    targets[0].get("src_path").unwrap().as_str().unwrap()
+                };
+
+                let file = {
+                    let content = fs::read_to_string(src_path).unwrap();
+                    syn::parse_file(&content).unwrap()
+                };
+
+                contains_aster_main_macro(&file)
+            })
+            .collect()
+    };
+
+    if packages.len() == 0 {
+        error_msg!("OSDK requires there's at least one kernel package. Please navigate to the kernel package directory or the workspace root and run the command.");
+        std::process::exit(Errno::BuildCrate as _);
+    }
+
+    if packages.len() >= 2 {
+        error_msg!("OSDK requires there's at most one kernel package in the workspace. Please navigate to the kernel package directory and run the command.");
+        std::process::exit(Errno::BuildCrate as _);
+    }
+
+    packages[0].get("id").unwrap().as_str().unwrap()
+}
+
+fn contains_aster_main_macro(file: &syn::File) -> bool {
+    for item in &file.items {
+        let syn::Item::Fn(item_fn) = item else {
+            continue;
+        };
+
+        for attr in &item_fn.attrs {
+            let attr = format!("{}", attr.to_token_stream());
+            if attr.as_str() == "# [aster_main]" {
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
 pub fn get_current_crate_info() -> CrateInfo {
     let metadata = get_cargo_metadata(None::<&str>, None::<&[&str]>).unwrap();
-    let default_members = metadata.get("workspace_default_members").unwrap();
-    assert_eq!(default_members.as_array().unwrap().len(), 1);
+
+    let default_member = get_default_member(&metadata);
+
     // The default member string here is in the form of "<crate_name> <crate_version> (path+file://<crate_path>)"
-    let default_member = default_members[0]
-        .as_str()
-        .unwrap()
-        .split(' ')
-        .collect::<Vec<&str>>();
+    let default_member = default_member.split(' ').collect::<Vec<&str>>();
     let name = default_member[0].to_string();
     let version = default_member[1].to_string();
     let path = default_member[2]