ci: treewide: deny used_underscore_binding (#31319)

* Enforce used_underscore_binding

* Fix all

* Work around for cfg()-ed code...

* ci....

* Make clipply fixes more pleasant

* Clone exit signal while intentionally shadowing

* Use more verbose code to avoid any #[allow(...)]s

ci/test-checks.sh

@@ -82,6 +82,7 @@ nightly_clippy_allows=()
    --deny=warnings \
    --deny=clippy::default_trait_access \
    --deny=clippy::integer_arithmetic \
+   --deny=clippy::used_underscore_binding \
    "${nightly_clippy_allows[@]}"
 
 if [[ -n $CI ]]; then

core/src/ancestor_hashes_service.rs

@@ -761,7 +761,6 @@ mod test {
         super::*,
         crate::{
             cluster_slot_state_verifier::{DuplicateSlotsToRepair, PurgeRepairSlotCounter},
-            repair_service::DuplicateSlotsResetReceiver,
             replay_stage::{
                 tests::{replay_blockstore_components, ReplayBlockstoreComponents},
                 ReplayStage,
@@ -1039,7 +1038,6 @@ mod test {
         repairable_dead_slot_pool: HashSet<Slot>,
         request_throttle: Vec<u64>,
         repair_stats: AncestorRepairRequestsStats,
-        _duplicate_slots_reset_receiver: DuplicateSlotsResetReceiver,
         retryable_slots_sender: RetryableSlotsSender,
         retryable_slots_receiver: RetryableSlotsReceiver,
         ancestor_hashes_replay_update_sender: AncestorHashesReplayUpdateSender,
@@ -1089,7 +1087,6 @@ mod test {
                 repairable_dead_slot_pool: HashSet::new(),
                 request_throttle: vec![],
                 repair_stats: AncestorRepairRequestsStats::default(),
-                _duplicate_slots_reset_receiver,
                 ancestor_hashes_replay_update_sender,
                 ancestor_hashes_replay_update_receiver,
                 retryable_slots_sender,

core/src/tvu.rs

@@ -426,7 +426,7 @@ pub mod tests {
         let bank_forks = Arc::new(RwLock::new(bank_forks));
         let max_complete_transaction_status_slot = Arc::new(AtomicU64::default());
         let max_complete_rewards_slot = Arc::new(AtomicU64::default());
-        let _ignored_prioritization_fee_cache = Arc::new(PrioritizationFeeCache::new(0u64));
+        let ignored_prioritization_fee_cache = Arc::new(PrioritizationFeeCache::new(0u64));
         let tvu = Tvu::new(
             &vote_keypair.pubkey(),
             Arc::new(RwLock::new(vec![Arc::new(vote_keypair)])),
@@ -476,7 +476,7 @@ pub mod tests {
             AbsRequestSender::default(),
             None,
             &Arc::new(ConnectionCache::default()),
-            &_ignored_prioritization_fee_cache,
+            &ignored_prioritization_fee_cache,
             BankingTracer::new_disabled(),
         )
         .expect("assume success");

core/src/window_service.rs

@@ -240,7 +240,6 @@ where
         let shred = Shred::new_from_serialized_shred(shred.to_vec()).ok()?;
         if packet.meta().repair() {
             let repair_info = RepairMeta {
-                _from_addr: packet.meta().socket_addr(),
                 // If can't parse the nonce, dump the packet.
                 nonce: repair_response::nonce(packet)?,
             };
@@ -292,7 +291,6 @@ where
 }
 
 struct RepairMeta {
-    _from_addr: SocketAddr,
     nonce: Nonce,
 }
 
@@ -573,10 +571,7 @@ mod test {
 
     #[test]
     fn test_prune_shreds() {
-        use {
+        use crate::serve_repair::ShredRepairType;
-            crate::serve_repair::ShredRepairType,
-            std::net::{IpAddr, Ipv4Addr},
-        };
         solana_logger::setup();
         let shred = Shred::new_from_parity_shard(
             5,   // slot
@@ -589,18 +584,14 @@ mod test {
             0,   // version
         );
         let mut shreds = vec![shred.clone(), shred.clone(), shred];
-        let _from_addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8080);
+        let repair_meta = RepairMeta { nonce: 0 };
-        let repair_meta = RepairMeta {
-            _from_addr,
-            nonce: 0,
-        };
         let outstanding_requests = Arc::new(RwLock::new(OutstandingShredRepairs::default()));
         let repair_type = ShredRepairType::Orphan(9);
         let nonce = outstanding_requests
             .write()
             .unwrap()
             .add_request(repair_type, timestamp());
-        let repair_meta1 = RepairMeta { _from_addr, nonce };
+        let repair_meta1 = RepairMeta { nonce };
         let mut repair_infos = vec![None, Some(repair_meta), Some(repair_meta1)];
         prune_shreds_invalid_repair(&mut shreds, &mut repair_infos, &outstanding_requests);
         assert_eq!(repair_infos.len(), 2);

core/tests/snapshots.rs

@@ -71,6 +71,8 @@ struct SnapshotTestConfig {
     full_snapshot_archives_dir: TempDir,
     bank_snapshots_dir: TempDir,
     accounts_dir: PathBuf,
+    // as the underscore prefix indicates, this isn't explictly used; but it's needed to keep
+    // TempDir::drop from running to retain that dir for the duration of test
     _accounts_tmp_dir: TempDir,
 }
 
@@ -82,7 +84,7 @@ impl SnapshotTestConfig {
         full_snapshot_archive_interval_slots: Slot,
         incremental_snapshot_archive_interval_slots: Slot,
     ) -> SnapshotTestConfig {
-        let (_accounts_tmp_dir, accounts_dir) = create_tmp_accounts_dir_for_tests();
+        let (accounts_tmp_dir, accounts_dir) = create_tmp_accounts_dir_for_tests();
         let bank_snapshots_dir = TempDir::new().unwrap();
         let full_snapshot_archives_dir = TempDir::new().unwrap();
         let incremental_snapshot_archives_dir = TempDir::new().unwrap();
@@ -128,7 +130,7 @@ impl SnapshotTestConfig {
             full_snapshot_archives_dir,
             bank_snapshots_dir,
             accounts_dir,
-            _accounts_tmp_dir,
+            _accounts_tmp_dir: accounts_tmp_dir,
         }
     }
 }

faucet/src/faucet.rs

@@ -389,11 +389,11 @@ pub async fn run_faucet(
     );
 
     loop {
-        let _faucet = faucet.clone();
+        let faucet = faucet.clone();
         match listener.accept().await {
             Ok((stream, _)) => {
                 tokio::spawn(async move {
-                    if let Err(e) = process(stream, _faucet).await {
+                    if let Err(e) = process(stream, faucet).await {
                         info!("failed to process request; error = {:?}", e);
                     }
                 });

ledger/src/blockstore_processor.rs

@@ -444,7 +444,7 @@ pub fn process_entries_for_tests(
             })
             .collect();
 
-    let _ignored_prioritization_fee_cache = PrioritizationFeeCache::new(0u64);
+    let ignored_prioritization_fee_cache = PrioritizationFeeCache::new(0u64);
     let result = process_entries(
         bank,
         &mut replay_entries,
@@ -453,7 +453,7 @@ pub fn process_entries_for_tests(
         replay_vote_sender,
         &mut batch_timing,
         None,
-        &_ignored_prioritization_fee_cache,
+        &ignored_prioritization_fee_cache,
     );
 
     debug!("process_entries: {:?}", batch_timing);
@@ -904,7 +904,7 @@ fn confirm_full_slot(
 ) -> result::Result<(), BlockstoreProcessorError> {
     let mut confirmation_timing = ConfirmationTiming::default();
     let skip_verification = !opts.run_verification;
-    let _ignored_prioritization_fee_cache = PrioritizationFeeCache::new(0u64);
+    let ignored_prioritization_fee_cache = PrioritizationFeeCache::new(0u64);
 
     confirm_slot(
         blockstore,
@@ -917,7 +917,7 @@ fn confirm_full_slot(
         recyclers,
         opts.allow_dead_slots,
         opts.runtime_config.log_messages_bytes_limit,
-        &_ignored_prioritization_fee_cache,
+        &ignored_prioritization_fee_cache,
     )?;
 
     timing.accumulate(&confirmation_timing.batch_execute.totals);

perf/src/cuda_runtime.rs

@@ -23,12 +23,12 @@ use {
 
 const CUDA_SUCCESS: c_int = 0;
 
-fn pin<T>(_mem: &mut Vec<T>) {
+fn pin<T>(mem: &mut Vec<T>) {
     if let Some(api) = perf_libs::api() {
         use std::{ffi::c_void, mem::size_of};
 
-        let ptr = _mem.as_mut_ptr();
+        let ptr = mem.as_mut_ptr();
-        let size = _mem.capacity().saturating_mul(size_of::<T>());
+        let size = mem.capacity().saturating_mul(size_of::<T>());
         let err = unsafe {
             (api.cuda_host_register)(ptr as *mut c_void, size, /*flags=*/ 0)
         };
@@ -39,14 +39,14 @@ fn pin<T>(_mem: &mut Vec<T>) {
     }
 }
 
-fn unpin<T>(_mem: *mut T) {
+fn unpin<T>(mem: *mut T) {
     if let Some(api) = perf_libs::api() {
         use std::ffi::c_void;
 
-        let err = unsafe { (api.cuda_host_unregister)(_mem as *mut c_void) };
+        let err = unsafe { (api.cuda_host_unregister)(mem as *mut c_void) };
         assert!(
             err == CUDA_SUCCESS,
-            "cudaHostUnregister returned: {err} ptr: {_mem:?}"
+            "cudaHostUnregister returned: {err} ptr: {mem:?}"
         );
     }
 }
@@ -277,21 +277,21 @@ impl<T: Clone + Default + Sized> PinnedVec<T> {
         self.x.shuffle(rng)
     }
 
-    fn check_ptr(&mut self, _old_ptr: *mut T, _old_capacity: usize, _from: &'static str) {
+    fn check_ptr(&mut self, old_ptr: *mut T, old_capacity: usize, from: &'static str) {
         let api = perf_libs::api();
         if api.is_some()
             && self.pinnable
-            && (self.x.as_ptr() != _old_ptr || self.x.capacity() != _old_capacity)
+            && (self.x.as_ptr() != old_ptr || self.x.capacity() != old_capacity)
         {
             if self.pinned {
-                unpin(_old_ptr);
+                unpin(old_ptr);
             }
 
             trace!(
                 "pinning from check_ptr old: {} size: {} from: {}",
-                _old_capacity,
+                old_capacity,
                 self.x.capacity(),
-                _from
+                from
             );
             pin(&mut self.x);
             self.pinned = true;

rpc-test/tests/rpc.rs

@@ -297,9 +297,9 @@ fn test_rpc_subscriptions() {
             let status_sender = status_sender.clone();
             let signature_subscription_ready_clone = signature_subscription_ready_clone.clone();
             tokio::spawn({
-                let _pubsub_client = Arc::clone(&pubsub_client);
+                let pubsub_client = Arc::clone(&pubsub_client);
                 async move {
-                    let (mut sig_notifications, sig_unsubscribe) = _pubsub_client
+                    let (mut sig_notifications, sig_unsubscribe) = pubsub_client
                         .signature_subscribe(
                             &signature,
                             Some(RpcSignatureSubscribeConfig {
@@ -324,9 +324,9 @@ fn test_rpc_subscriptions() {
             let account_sender = account_sender.clone();
             let account_subscription_ready_clone = account_subscription_ready_clone.clone();
             tokio::spawn({
-                let _pubsub_client = Arc::clone(&pubsub_client);
+                let pubsub_client = Arc::clone(&pubsub_client);
                 async move {
-                    let (mut account_notifications, account_unsubscribe) = _pubsub_client
+                    let (mut account_notifications, account_unsubscribe) = pubsub_client
                         .account_subscribe(
                             &pubkey,
                             Some(RpcAccountInfoConfig {

runtime/src/accounts_index.rs

@@ -3404,10 +3404,10 @@ pub mod tests {
         index.unchecked_scan_accounts(
             "",
             &Ancestors::default(),
-            |pubkey, _index| {
+            |pubkey, index| {
                 if pubkey == &key {
                     found_key = true;
-                    assert_eq!(_index, (&true, 3));
+                    assert_eq!(index, (&true, 3));
                 };
                 num += 1
             },

sdk/program/src/pubkey.rs

@@ -158,6 +158,7 @@ impl TryFrom<&str> for Pubkey {
     }
 }
 
+#[allow(clippy::used_underscore_binding)]
 pub fn bytes_are_curve_point<T: AsRef<[u8]>>(_bytes: T) -> bool {
     #[cfg(not(target_os = "solana"))]
     {

sdk/program/src/vote/state/mod.rs

@@ -341,6 +341,7 @@ impl VoteState {
         3762 // see test_vote_state_size_of.
     }
 
+    #[allow(clippy::used_underscore_binding)]
     pub fn deserialize(_input: &[u8]) -> Result<Self, InstructionError> {
         #[cfg(not(target_os = "solana"))]
         {

tokens/src/main.rs

@@ -31,10 +31,12 @@ fn main() -> Result<(), Box<dyn Error>> {
     let client = RpcClient::new(json_rpc_url);
 
     let exit = Arc::new(AtomicBool::default());
-    let _exit = exit.clone();
     // Initialize CTRL-C handler to ensure db changes are written before exit.
-    ctrlc::set_handler(move || {
+    ctrlc::set_handler({
-        _exit.store(true, Ordering::SeqCst);
+        let exit = exit.clone();
+        move || {
+            exit.store(true, Ordering::SeqCst);
+        }
     })
     .expect("Error setting Ctrl-C handler");