Add rust lint CI job.

rust/lib/mammoth/src/cap_syscall.rs

@@ -2,7 +2,6 @@ use core::ffi::c_void;
 
 use crate::zion::{self, z_cap_t, ZError};
 
-#[must_use]
 fn syscall<T>(id: u64, req: &T) -> Result<(), ZError> {
     unsafe {
         let resp = zion::SysCall1(id, req as *const T as *const c_void);

rust/lib/mammoth/src/elf.rs

@@ -1,5 +1,4 @@
 use crate::cap::Capability;
-use crate::debug;
 use crate::init;
 use crate::syscall;
 use crate::zion::ZError;
@@ -237,7 +236,7 @@ fn load_program_segment(
             let page_offset = prog_header.vaddr & 0xFFF;
             let mem_size = page_offset + prog_header.mem_size;
 
-            let mem_object = crate::mem::MemoryRegion::new(mem_size)?;
+            let mut mem_object = crate::mem::MemoryRegion::new(mem_size)?;
 
             for i in mem_object.mut_slice() {
                 *i = 0;

rust/lib/mammoth/src/init.rs

@@ -28,7 +28,7 @@ pub fn parse_init_port(port_cap: z_cap_t) {
         let mut caps: [u64; 1] = [0];
 
         let resp = syscall::port_poll(&init_port, &mut bytes, &mut caps);
-        if let Err(_) = resp {
+        if resp.is_err() {
             break;
         }
 

rust/lib/mammoth/src/macros.rs

@@ -2,21 +2,20 @@ use alloc::string::String;
 use alloc::vec::Vec;
 use core::fmt;
 
+#[derive(Default)]
 pub struct Writer {
     int_vec: Vec<u8>,
 }
 
 impl Writer {
     pub fn new() -> Self {
-        Self {
-            int_vec: Vec::new(),
-        }
+        Writer::default()
     }
 }
 
-impl Into<String> for Writer {
-    fn into(self) -> String {
-        String::from_utf8(self.int_vec).expect("Failed to convert")
+impl From<Writer> for String {
+    fn from(value: Writer) -> Self {
+        String::from_utf8(value.int_vec).expect("Failed to convert")
     }
 }
 

rust/lib/mammoth/src/mem.rs

@@ -85,7 +85,7 @@ impl MemoryRegion {
         }
     }
 
-    pub fn mut_slice<T>(&self) -> &mut [T] {
+    pub fn mut_slice<T>(&mut self) -> &mut [T] {
         unsafe {
             slice::from_raw_parts_mut(
                 self.virt_addr as *mut T,

rust/lib/mammoth/src/sync.rs

@@ -50,7 +50,7 @@ impl<T> DerefMut for MutexGuard<'_, T> {
     }
 }
 
-impl<T> Mutex<T> {
+impl<'a, T> Mutex<T> {
     pub fn new(data: T) -> Mutex<T> {
         Mutex {
             cap: syscall::mutex_create().unwrap(),
@@ -58,7 +58,7 @@ impl<T> Mutex<T> {
         }
     }
 
-    pub fn lock(&self) -> MutexGuard<T> {
+    pub fn lock(&'a self) -> MutexGuard<'a, T> {
         syscall::mutex_lock(&self.cap).unwrap();
 
         MutexGuard { mutex: self }
@@ -70,3 +70,12 @@ impl<T> Drop for MutexGuard<'_, T> {
         syscall::mutex_release(&self.mutex.cap).unwrap();
     }
 }
+
+impl<T> Default for Mutex<T>
+where
+    T: Default,
+{
+    fn default() -> Self {
+        Self::new(T::default())
+    }
+}

rust/lib/mammoth/src/syscall.rs

@@ -9,7 +9,6 @@ use core::ffi::c_void;
 #[cfg(feature = "hosted")]
 use core::panic::PanicInfo;
 
-#[must_use]
 fn syscall<T>(id: u64, req: &T) -> Result<(), ZError> {
     unsafe {
         let resp = zion::SysCall1(id, req as *const T as *const c_void);

rust/lib/mammoth/src/task/mod.rs

@@ -48,7 +48,7 @@ struct TaskWaker {
 }
 
 impl TaskWaker {
-    fn new(task_id: TaskId, task_queue: Arc<Mutex<VecDeque<TaskId>>>) -> Waker {
+    fn create_waker(task_id: TaskId, task_queue: Arc<Mutex<VecDeque<TaskId>>>) -> Waker {
         Waker::from(Arc::new(TaskWaker {
             task_id,
             task_queue,
@@ -69,6 +69,7 @@ impl Wake for TaskWaker {
     }
 }
 
+#[derive(Default)]
 pub struct Executor {
     tasks: Arc<Mutex<BTreeMap<TaskId, Task>>>,
     // TODO: Consider a better datastructure for this.
@@ -78,11 +79,7 @@ pub struct Executor {
 
 impl Executor {
     pub fn new() -> Executor {
-        Executor {
-            tasks: Arc::new(Mutex::new(BTreeMap::new())),
-            task_queue: Arc::new(Mutex::new(VecDeque::new())),
-            waker_cache: BTreeMap::new(),
-        }
+        Executor::default()
     }
 
     pub fn spawn(&mut self, task: Task) {
@@ -100,7 +97,7 @@ impl Executor {
             let waker = self
                 .waker_cache
                 .entry(task_id)
-                .or_insert_with(|| TaskWaker::new(task_id, self.task_queue.clone()));
+                .or_insert_with(|| TaskWaker::create_waker(task_id, self.task_queue.clone()));
             let mut ctx = Context::from_waker(waker);
             match task.poll(&mut ctx) {
                 Poll::Ready(()) => {

rust/lib/mammoth/src/thread.rs

@@ -40,7 +40,7 @@ where
     let raw_main = Box::into_raw(Box::new(main));
     let proc_cap = Capability::take_copy(unsafe { crate::init::SELF_PROC_CAP }).unwrap();
     let cap = syscall::thread_create(&proc_cap).unwrap();
-    syscall::thread_start(&cap, entry_point as u64, raw_main as u64, 0).unwrap();
+    syscall::thread_start(&cap, entry_point as usize as u64, raw_main as u64, 0).unwrap();
 
     JoinHandle { cap }
 }