macros: suppress clippy::default_numeric_fallback lint in generated code (#3831)

Author: taiki-e

.clippy.toml

@@ -0,0 +1 @@
+msrv = "1.45"

.github/workflows/ci.yml

@@ -265,7 +265,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install Rust
-        run: rustup update ${{ env.minrust }} && rustup default ${{ env.minrust }}
+        run: rustup update 1.52.1 && rustup default 1.52.1
       - name: Install clippy
         run: rustup component add clippy
 

tokio-stream/tests/async_send_sync.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::diverging_sub_expression)]
+
 use std::rc::Rc;
 
 #[allow(dead_code)]

tokio-util/tests/poll_semaphore.rs

@@ -6,9 +6,9 @@ use tokio_util::sync::PollSemaphore;
 
 type SemRet = Option<OwnedSemaphorePermit>;
 
-fn semaphore_poll<'a>(
-    sem: &'a mut PollSemaphore,
-) -> tokio_test::task::Spawn<impl Future<Output = SemRet> + 'a> {
+fn semaphore_poll(
+    sem: &mut PollSemaphore,
+) -> tokio_test::task::Spawn<impl Future<Output = SemRet> + '_> {
     let fut = futures::future::poll_fn(move |cx| sem.poll_acquire(cx));
     tokio_test::task::spawn(fut)
 }

tokio/src/macros/select.rs

@@ -398,7 +398,7 @@ macro_rules! select {
         // set the appropriate bit in `disabled`.
         $(
             if !$c {
-                let mask = 1 << $crate::count!( $($skip)* );
+                let mask: util::Mask = 1 << $crate::count!( $($skip)* );
                 disabled |= mask;
             }
         )*

tokio/src/runtime/task/state.rs

@@ -29,12 +29,15 @@ const LIFECYCLE_MASK: usize = 0b11;
 const NOTIFIED: usize = 0b100;
 
 /// The join handle is still around
+#[allow(clippy::unusual_byte_groupings)] // https://github.com/rust-lang/rust-clippy/issues/6556
 const JOIN_INTEREST: usize = 0b1_000;
 
 /// A join handle waker has been set
+#[allow(clippy::unusual_byte_groupings)] // https://github.com/rust-lang/rust-clippy/issues/6556
 const JOIN_WAKER: usize = 0b10_000;
 
 /// The task has been forcibly cancelled.
+#[allow(clippy::unusual_byte_groupings)] // https://github.com/rust-lang/rust-clippy/issues/6556
 const CANCELLED: usize = 0b100_000;
 
 /// All bits

tokio/src/util/linked_list.rs

@@ -50,6 +50,7 @@ pub(crate) unsafe trait Link {
     type Target;
 
     /// Convert the handle to a raw pointer without consuming the handle
+    #[allow(clippy::wrong_self_convention)]
     fn as_raw(handle: &Self::Handle) -> NonNull<Self::Target>;
 
     /// Convert the raw pointer to a handle

tokio/src/util/wake.rs

@@ -54,11 +54,7 @@ unsafe fn inc_ref_count<T: Wake>(data: *const ()) {
     let arc = ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
 
     // Now increase refcount, but don't drop new refcount either
-    let arc_clone: ManuallyDrop<_> = arc.clone();
-
-    // Drop explicitly to avoid clippy warnings
-    drop(arc);
-    drop(arc_clone);
+    let _arc_clone: ManuallyDrop<_> = arc.clone();
 }
 
 unsafe fn clone_arc_raw<T: Wake>(data: *const ()) -> RawWaker {

tokio/tests/async_send_sync.rs

@@ -1,6 +1,6 @@
 #![warn(rust_2018_idioms)]
 #![cfg(feature = "full")]
-#![allow(clippy::type_complexity)]
+#![allow(clippy::type_complexity, clippy::diverging_sub_expression)]
 
 use std::cell::Cell;
 use std::future::Future;

tokio/tests/macros_select.rs

@@ -537,3 +537,13 @@ async fn biased_eventually_ready() {
 
     assert_eq!(count, 3);
 }
+
+// https://github.com/tokio-rs/tokio/issues/3830
+// https://github.com/rust-lang/rust-clippy/issues/7304
+#[warn(clippy::default_numeric_fallback)]
+pub async fn default_numeric_fallback() {
+    tokio::select! {
+        _ = async {} => (),
+        else => (),
+    }
+}