Fix Occlum building warnings

src/libos/src/error/to_errno.rs

@@ -109,7 +109,7 @@ impl ToErrno for std::alloc::AllocError {
     }
 }
 
-impl ToErrno for std::alloc::LayoutErr {
+impl ToErrno for std::alloc::LayoutError {
     fn errno(&self) -> Errno {
         EINVAL
     }

src/libos/src/events/waiter.rs

@@ -154,8 +154,8 @@ impl Inner {
     pub fn wake(&self) {
         if self
             .is_woken
-            .compare_and_swap(false, true, Ordering::SeqCst)
-            == false
+            .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
+            .is_ok()
         {
             self.host_eventfd.write_u64(1);
         }
@@ -167,8 +167,8 @@ impl Inner {
             .filter(|inner| {
                 inner
                     .is_woken
-                    .compare_and_swap(false, true, Ordering::SeqCst)
-                    == false
+                    .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
+                    .is_ok()
             })
             .map(|inner| inner.host_eventfd.host_fd())
             .collect::<Vec<FileDesc>>();

src/libos/src/fs/events.rs

@@ -71,8 +71,9 @@ impl AtomicIoEvents for Atomic<IoEvents> {
             let new_val = old_val & !*mask | *ready;
             let success_ordering = ordering;
             let failure_ordering = Ordering::Relaxed;
-            if let Ok(_) =
-                self.compare_exchange(old_val, new_val, success_ordering, failure_ordering)
+            if self
+                .compare_exchange(old_val, new_val, success_ordering, failure_ordering)
+                .is_ok()
             {
                 return;
             }

src/libos/src/net/io_multiplexing/mod.rs

@@ -19,5 +19,4 @@ use fs::{AsEvent, AsINodeFile, AsTimer, CreationFlags, File, FileDesc, FileRef,
 use std::any::Any;
 use std::convert::TryFrom;
 use std::fmt;
-use std::sync::atomic::spin_loop_hint;
 use time::timeval_t;

src/libos/src/syscall/mod.rs

@@ -563,10 +563,10 @@ process_syscall_table_with_callback!(impl_fmt_syscall);
 /// Generate the code that can dispatch any system call to its actual implementation function.
 macro_rules! impl_dispatch_syscall {
     (@do_syscall $fn:ident, $syscall:ident, $arg_i:expr, ($(,)?) -> ($($output:tt)*) ) => {
-        impl_dispatch_syscall!(@as_expr $fn($($output)*));
+        impl_dispatch_syscall!(@as_expr $fn($($output)*))
     };
     (@do_syscall $fn:ident, $syscall:ident, $arg_i:expr, ($_arg_name:ident : $arg_type:ty, $($more_args:tt)*) -> ($($output:tt)*)) => {
-        impl_dispatch_syscall!(@do_syscall $fn, $syscall, ($arg_i + 1), ($($more_args)*) -> ($($output)* ($syscall.args[$arg_i] as $arg_type),));
+        impl_dispatch_syscall!(@do_syscall $fn, $syscall, ($arg_i + 1), ($($more_args)*) -> ($($output)* ($syscall.args[$arg_i] as $arg_type),))
     };
     (@as_expr $e:expr) => { $e };
 

src/libos/src/util/sync/rw_lock/inner.rs

@@ -52,7 +52,8 @@
 use super::*;
 
 use crate::process::{futex_wait, futex_wake};
-use std::sync::atomic::{spin_loop_hint, AtomicI32, Ordering};
+use std::hint;
+use std::sync::atomic::{AtomicI32, Ordering};
 
 // The implementaion of RwLock
 //
@@ -97,7 +98,7 @@ impl RwLockInner {
             && self.rw_lock.load(Ordering::SeqCst) != 0
             && self.rw_waiters.load(Ordering::SeqCst) == 0
         {
-            spin_loop_hint();
+            hint::spin_loop();
             spins -= 1;
         }
 
@@ -121,7 +122,8 @@ impl RwLockInner {
             self.rw_waiters.fetch_add(1, Ordering::SeqCst);
 
             let tmp = (val as u32 | 0x8000_0000) as i32;
-            self.rw_lock.compare_and_swap(val, tmp, Ordering::SeqCst);
+            self.rw_lock
+                .compare_exchange(val, tmp, Ordering::SeqCst, Ordering::SeqCst);
             ret = futex_wait(&self.rw_lock as *const _ as *const i32, tmp, &None);
 
             self.rw_waiters.fetch_sub(1, Ordering::SeqCst);
@@ -148,8 +150,8 @@ impl RwLockInner {
 
             if self
                 .rw_lock
-                .compare_and_swap(val, val + 1, Ordering::SeqCst)
-                == val
+                .compare_exchange(val, val + 1, Ordering::SeqCst, Ordering::SeqCst)
+                .is_ok()
             {
                 break;
             }
@@ -168,7 +170,7 @@ impl RwLockInner {
             && self.rw_lock.load(Ordering::SeqCst) != 0
             && self.rw_waiters.load(Ordering::SeqCst) == 0
         {
-            spin_loop_hint();
+            hint::spin_loop();
             spins -= 1;
         }
 
@@ -186,7 +188,8 @@ impl RwLockInner {
             self.rw_waiters.fetch_add(1, Ordering::SeqCst);
 
             let tmp = (val as u32 | 0x8000_0000) as i32;
-            self.rw_lock.compare_and_swap(val, tmp, Ordering::SeqCst);
+            self.rw_lock
+                .compare_exchange(val, tmp, Ordering::SeqCst, Ordering::SeqCst);
             ret = futex_wait(&self.rw_lock as *const _ as *const i32, tmp, &None);
 
             self.rw_waiters.fetch_sub(1, Ordering::SeqCst);
@@ -201,12 +204,14 @@ impl RwLockInner {
     }
 
     pub fn try_write(&self) -> Result<()> {
-        let val = self
+        if self
             .rw_lock
-            .compare_and_swap(0, 0x7FFF_FFFF, Ordering::SeqCst);
-        match val {
-            0 => Ok(()),
-            _ => return_errno!(EBUSY, "the lock is held for reading or writing"),
+            .compare_exchange(0, 0x7FFF_FFFF, Ordering::SeqCst, Ordering::SeqCst)
+            .is_ok()
+        {
+            Ok(())
+        } else {
+            Err(errno!(EBUSY, "the lock is held for reading or writing"))
         }
     }
 
@@ -227,7 +232,11 @@ impl RwLockInner {
                 _ => val - 1,
             };
 
-            if self.rw_lock.compare_and_swap(val, new, Ordering::SeqCst) == val {
+            if self
+                .rw_lock
+                .compare_exchange(val, new, Ordering::SeqCst, Ordering::SeqCst)
+                .is_ok()
+            {
                 break;
             }
         }