Refactor the parsing of OSDK crate types

osdk/src/cli.rs

@@ -303,7 +303,7 @@ impl DebugProfileOutArgs {
                         .display()
                 )
             } else {
-                let crate_name = crate::util::get_current_crate_info().name;
+                let crate_name = crate::util::get_current_crates().remove(0).name;
                 let time_stamp = std::time::SystemTime::now();
                 let time_stamp: DateTime<Local> = time_stamp.into();
                 let time_stamp = time_stamp.format("%H%M%S");

osdk/src/commands/build/bin.rs

@@ -17,7 +17,7 @@ use crate::{
         bin::{AsterBin, AsterBinType, AsterBzImageMeta, AsterElfMeta},
         file::BundleFile,
     },
-    util::{get_current_crate_info, hard_link_or_copy},
+    util::{get_current_crates, hard_link_or_copy},
 };
 
 pub fn make_install_bzimage(
@@ -27,7 +27,7 @@ pub fn make_install_bzimage(
     linux_x86_legacy_boot: bool,
     encoding: PayloadEncoding,
 ) -> AsterBin {
-    let target_name = get_current_crate_info().name;
+    let target_name = get_current_crates().remove(0).name;
     let image_type = if linux_x86_legacy_boot {
         BzImageType::Legacy32
     } else {

osdk/src/commands/build/grub.rs

@@ -16,7 +16,7 @@ use crate::{
         scheme::{ActionChoice, BootProtocol},
         Config,
     },
-    util::{get_current_crate_info, hard_link_or_copy},
+    util::{get_current_crates, hard_link_or_copy},
 };
 
 pub fn create_bootdev_image(
@@ -26,7 +26,7 @@ pub fn create_bootdev_image(
     config: &Config,
     action: ActionChoice,
 ) -> AsterVmImage {
-    let target_name = get_current_crate_info().name;
+    let target_name = get_current_crates().remove(0).name;
     let iso_root = &target_dir.as_ref().join("iso_root");
     let action = match &action {
         ActionChoice::Run => &config.run,
@@ -108,7 +108,7 @@ fn generate_grub_cfg(
     initramfs_path: Option<String>,
     protocol: &BootProtocol,
 ) -> String {
-    let target_name = get_current_crate_info().name;
+    let target_name = get_current_crates().remove(0).name;
     let grub_cfg = include_str!("grub.cfg.template").to_string();
 
     // Delete the first two lines that notes the file a template file.

osdk/src/commands/build/mod.rs

@@ -29,7 +29,7 @@ use crate::{
     },
     error::Errno,
     error_msg,
-    util::{get_cargo_metadata, get_current_crate_info, get_target_directory},
+    util::{get_cargo_metadata, get_current_crates, get_target_directory},
 };
 
 pub fn execute_build_command(config: &Config, build_args: &BuildArgs) {
@@ -41,8 +41,22 @@ pub fn execute_build_command(config: &Config, build_args: &BuildArgs) {
     if !osdk_output_directory.exists() {
         std::fs::create_dir_all(&osdk_output_directory).unwrap();
     }
-    let target_info = get_current_crate_info();
+
-    let bundle_path = osdk_output_directory.join(target_info.name);
+    let targets = get_current_crates();
+    let mut target_info = None;
+    for target in targets {
+        if target.is_kernel_crate {
+            target_info = Some(target);
+            break;
+        }
+    }
+
+    let target_info = target_info.unwrap_or_else(|| {
+        error_msg!("No kernel crate found in the current workspace");
+        process::exit(Errno::NoKernelCrate as _);
+    });
+
+    let bundle_path = osdk_output_directory.join(target_info.name.clone());
 
     let action = if build_args.for_test {
         ActionChoice::Test
@@ -71,8 +85,8 @@ pub fn create_base_and_cached_build(
     let base_crate_path = osdk_output_directory.as_ref().join("base");
     new_base_crate(
         &base_crate_path,
-        &get_current_crate_info().name,
+        &get_current_crates().remove(0).name,
-        get_current_crate_info().path,
+        get_current_crates().remove(0).path,
         false,
     );
     let original_dir = std::env::current_dir().unwrap();
@@ -251,7 +265,7 @@ fn build_kernel_elf(
         .as_ref()
         .join(&target_os_string)
         .join(profile_name_adapter(profile))
-        .join(get_current_crate_info().name);
+        .join(get_current_crates().remove(0).name);
 
     AsterBin::new(
         aster_bin_path,
@@ -262,7 +276,7 @@ fn build_kernel_elf(
             has_multiboot_header: true,
             has_multiboot2_header: true,
         }),
-        get_current_crate_info().version,
+        get_current_crates().remove(0).version,
         false,
     )
 }

osdk/src/commands/debug.rs

@@ -3,7 +3,7 @@
 use crate::{
     cli::DebugArgs,
     commands::util::bin_file_name,
-    util::{get_current_crate_info, get_target_directory},
+    util::{get_current_crates, get_target_directory},
 };
 use std::process::Command;
 
@@ -12,7 +12,7 @@ pub fn execute_debug_command(_profile: &str, args: &DebugArgs) {
 
     let file_path = get_target_directory()
         .join("osdk")
-        .join(get_current_crate_info().name)
+        .join(get_current_crates().remove(0).name)
         .join(bin_file_name());
     println!("Debugging {}", file_path.display());
 

osdk/src/commands/profile.rs

@@ -13,7 +13,7 @@ use inferno::flamegraph;
 use crate::{
     cli::{ProfileArgs, ProfileFormat},
     commands::util::bin_file_name,
-    util::{get_current_crate_info, get_target_directory},
+    util::{get_current_crates, get_target_directory},
 };
 use regex::Regex;
 use std::{collections::HashMap, fs::File, io::Write, path::PathBuf, process::Command};
@@ -45,7 +45,7 @@ fn do_parse_stack_traces(target_file: &PathBuf, args: &ProfileArgs) {
 fn do_collect_stack_traces(args: &ProfileArgs) {
     let file_path = get_target_directory()
         .join("osdk")
-        .join(get_current_crate_info().name)
+        .join(get_current_crates().remove(0).name)
         .join(bin_file_name());
 
     let remote = &args.remote;

osdk/src/commands/run.rs

@@ -12,14 +12,27 @@ use crate::{
     config::{scheme::ActionChoice, Config},
     error::Errno,
     error_msg,
-    util::{get_current_crate_info, get_target_directory},
+    util::{get_current_crates, get_target_directory},
     warn_msg,
 };
 
 pub fn execute_run_command(config: &Config, gdb_server_args: Option<&str>) {
     let cargo_target_directory = get_target_directory();
     let osdk_output_directory = cargo_target_directory.join(DEFAULT_TARGET_RELPATH);
-    let target_name = get_current_crate_info().name;
+
+    let targets = get_current_crates();
+    let mut target_name = None;
+    for target in targets {
+        if target.is_kernel_crate {
+            target_name = Some(target.name);
+            break;
+        }
+    }
+
+    let target_name = target_name.unwrap_or_else(|| {
+        error_msg!("No kernel crate found in the current workspace");
+        exit(Errno::NoKernelCrate as _);
+    });
 
     let mut config = config.clone();
 
@@ -173,7 +186,7 @@ mod gdb {
 mod vsc {
     use crate::{
         commands::util::bin_file_name,
-        util::{get_cargo_metadata, get_current_crate_info},
+        util::{get_cargo_metadata, get_current_crates},
     };
     use serde_json::{from_str, Value};
     use std::{
@@ -287,7 +300,7 @@ mod vsc {
     ) -> Result<(), std::io::Error> {
         let contents = include_str!("launch.json.template")
             .replace("#PROFILE#", profile)
-            .replace("#CRATE_NAME#", &get_current_crate_info().name)
+            .replace("#CRATE_NAME#", &get_current_crates().remove(0).name)
             .replace("#BIN_NAME#", &bin_file_name())
             .replace(
                 "#ADDR_PORT#",

osdk/src/commands/test.rs

@@ -9,21 +9,19 @@ use crate::{
     config::{scheme::ActionChoice, Config},
     error::Errno,
     error_msg,
-    util::{
+    util::{get_current_crates, get_target_directory},
-        get_cargo_metadata, get_current_crate_info, get_target_directory, parse_package_id_string,
-    },
 };
 
 pub fn execute_test_command(config: &Config, args: &TestArgs) {
-    let crates = get_workspace_default_members();
+    let crates = get_current_crates();
-    for crate_path in crates {
+    for crate_info in crates {
-        std::env::set_current_dir(crate_path).unwrap();
+        std::env::set_current_dir(crate_info.path).unwrap();
         test_current_crate(config, args);
     }
 }
 
 pub fn test_current_crate(config: &Config, args: &TestArgs) {
-    let current_crate = get_current_crate_info();
+    let current_crate = get_current_crates().remove(0);
     let cargo_target_directory = get_target_directory();
     let osdk_output_directory = cargo_target_directory.join(DEFAULT_TARGET_RELPATH);
     // Use a different name for better separation and reusability of `run` and `test`
@@ -87,7 +85,7 @@ pub static KTEST_CRATE_WHITELIST: Option<&[&str]> = Some(&{:#?});
     fs::write(&main_rs_path, main_rs_content).unwrap();
 
     // Build the kernel with the given base crate
-    let target_name = get_current_crate_info().name;
+    let target_name = get_current_crates().remove(0).name;
     let default_bundle_directory = osdk_output_directory.join(target_name);
     let original_dir = std::env::current_dir().unwrap();
     std::env::set_current_dir(&target_crate_dir).unwrap();
@@ -104,20 +102,3 @@ pub static KTEST_CRATE_WHITELIST: Option<&[&str]> = Some(&{:#?});
 
     bundle.run(config, ActionChoice::Test);
 }
-
-fn get_workspace_default_members() -> Vec<String> {
-    let metadata = get_cargo_metadata(None::<&str>, None::<&[&str]>).unwrap();
-    let default_members = metadata
-        .get("workspace_default_members")
-        .unwrap()
-        .as_array()
-        .unwrap();
-    default_members
-        .iter()
-        .map(|value| {
-            let default_member = value.as_str().unwrap();
-            let crate_info = parse_package_id_string(default_member);
-            crate_info.path
-        })
-        .collect()
-}

osdk/src/commands/util.rs

@@ -2,7 +2,7 @@
 
 use std::process::Command;
 
-use crate::util::get_current_crate_info;
+use crate::util::get_current_crates;
 
 pub const COMMON_CARGO_ARGS: &[&str] = &[
     "-Zbuild-std=core,alloc,compiler_builtins",
@@ -23,7 +23,7 @@ pub fn profile_name_adapter(profile: &str) -> &str {
 }
 
 pub fn bin_file_name() -> String {
-    get_current_crate_info().name + "-osdk-bin"
+    get_current_crates().remove(0).name + "-osdk-bin"
 }
 
 pub(crate) fn is_tdx_enabled() -> bool {

osdk/src/error.rs

@@ -12,6 +12,7 @@ pub enum Errno {
     BuildCrate = 7,
     RunBundle = 8,
     BadCrateName = 9,
+    NoKernelCrate = 10,
 }
 
 /// Print error message to console

osdk/src/util.rs

@@ -1,11 +1,13 @@
 // SPDX-License-Identifier: MPL-2.0
 
 use std::{
+    collections::HashMap,
     ffi::OsStr,
     fs::{self, File},
     io::{BufRead, BufReader, Result, Write},
     path::{Path, PathBuf},
     process::Command,
+    sync::{LazyLock, Mutex},
 };
 
 use crate::{error::Errno, error_msg};
@@ -73,41 +75,76 @@ pub fn get_target_directory() -> PathBuf {
         .into()
 }
 
+/// Information about an OSDK crate.
+#[derive(Debug, Clone)]
 pub struct CrateInfo {
     pub name: String,
     pub version: String,
     pub path: String,
+    /// Whether the crate is a kernel crate.
+    ///
+    /// If a crate contains the `ostd::main` macro, it is a kernel crate (akin
+    /// to the binary crate in a normal Rust project, but it is a library from
+    /// the perspective of Cargo).
+    pub is_kernel_crate: bool,
 }
 
-/// Retrieve the default member in the workspace.
+/// Gets the default crates in the current directory.
-///
+pub fn get_current_crates() -> Vec<CrateInfo> {
-/// If there is only one kernel crate, return that crate;
+    // To avoid the overhead of parsing the Cargo metadata and reading the
-/// If there are multiple kernel crates or no kernel crates in the workspace,
+    // source multiple times.
-/// this function will exit with an error.
+    static MEMOIZED: LazyLock<Mutex<HashMap<PathBuf, Vec<CrateInfo>>>> =
-///
+        LazyLock::new(|| Mutex::new(HashMap::new()));
-/// A crate is considered a kernel crate if it utilizes the `ostd::main` macro.
+
-fn get_default_member(metadata: &serde_json::Value) -> &str {
+    let current_dir = std::env::current_dir().unwrap();
+    let mut memoized = MEMOIZED.lock().unwrap();
+    if let Some(crates) = memoized.get(&current_dir) {
+        return crates.clone();
+    }
+
+    // If the current directory's crate info is not memoized, parse the Cargo
+    // metadata.
+
+    let metadata = get_cargo_metadata(None::<&str>, None::<&[&str]>).unwrap();
+    let packages = metadata.get("packages").unwrap().as_array().unwrap();
+
     let default_members = metadata
         .get("workspace_default_members")
         .unwrap()
         .as_array()
         .unwrap();
 
-    if default_members.len() == 1 {
+    let mut result = Vec::new();
-        return default_members[0].as_str().unwrap();
-    }
 
-    let packages: Vec<_> = {
+    for member in default_members {
-        let packages = metadata.get("packages").unwrap().as_array().unwrap();
+        let member_meta = packages
-
-        packages
             .iter()
-            .filter(|package| {
+            .find(|p| {
-                let id = package.get("id").unwrap();
+                let Some(p_id) = p.get("id") else {
-                if !default_members.contains(id) {
                     return false;
+                };
+                p_id == member
+            })
+            .unwrap();
+
+        let is_kernel_crate = package_contains_ostd_main(member_meta);
+
+        let parsed_id = parse_package_id_string(member.as_str().unwrap());
+
+        result.push(CrateInfo {
+            name: parsed_id.name,
+            version: parsed_id.version,
+            path: parsed_id.path,
+            is_kernel_crate,
+        });
     }
 
+    memoized.insert(current_dir, result.clone());
+
+    result
+}
+
+fn package_contains_ostd_main(package: &serde_json::Value) -> bool {
     let src_path = {
         let targets = package.get("targets").unwrap().as_array().unwrap();
         if targets.len() != 1 {
@@ -121,25 +158,10 @@ fn get_default_member(metadata: &serde_json::Value) -> &str {
         syn::parse_file(&content).unwrap()
     };
 
-                contains_ostd_main_macro(&file)
+    file_contains_ostd_main_macro(&file)
-            })
-            .collect()
-    };
-
-    if packages.is_empty() {
-        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 {
+fn file_contains_ostd_main_macro(file: &syn::File) -> bool {
-        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_ostd_main_macro(file: &syn::File) -> bool {
     for item in &file.items {
         let syn::Item::Fn(item_fn) = item else {
             continue;
@@ -156,14 +178,13 @@ fn contains_ostd_main_macro(file: &syn::File) -> bool {
     false
 }
 
-pub fn get_current_crate_info() -> CrateInfo {
+struct ParsedID {
-    let metadata = get_cargo_metadata(None::<&str>, None::<&[&str]>).unwrap();
+    pub name: String,
-
+    pub version: String,
-    let default_member = get_default_member(&metadata);
+    pub path: String,
-    parse_package_id_string(default_member)
 }
 
-pub fn parse_package_id_string(package_id: &str) -> CrateInfo {
+fn parse_package_id_string(package_id: &str) -> ParsedID {
     // Prior to 202403 (Rust 1.77.1), the package id string here is in the form of
     // "<crate_name> <crate_version> (path+file://<crate_path>)".
     // After that, it's
@@ -173,7 +194,7 @@ pub fn parse_package_id_string(package_id: &str) -> CrateInfo {
         // After 1.77.1
         if package_id.contains('@') {
             let package_id_segments = package_id.split(['#', '@']).collect::<Vec<&str>>();
-            CrateInfo {
+            ParsedID {
                 name: package_id_segments[1].to_string(),
                 version: package_id_segments[2].to_string(),
                 path: package_id_segments[0]
@@ -185,7 +206,7 @@ pub fn parse_package_id_string(package_id: &str) -> CrateInfo {
             let path = package_id_segments[0]
                 .trim_start_matches("path+file://")
                 .to_string();
-            CrateInfo {
+            ParsedID {
                 name: PathBuf::from(path.clone())
                     .file_name()
                     .unwrap()
@@ -199,7 +220,7 @@ pub fn parse_package_id_string(package_id: &str) -> CrateInfo {
     } else {
         // Before 1.77.1
         let default_member = package_id.split(' ').collect::<Vec<&str>>();
-        CrateInfo {
+        ParsedID {
             name: default_member[0].to_string(),
             version: default_member[1].to_string(),
             path: default_member[2]