add clippy to CI

.gitlab-ci.yml

@@ -268,6 +268,14 @@ cargo-fmt:
     - cargo +nightly fmt --all -- --check
   allow_failure:                   true
 
+cargo-clippy:
+  stage:                           test
+  <<:                              *docker-env
+  <<:                              *test-refs
+  script:
+    - ./.maintain/clippy.sh
+  allow_failure:                   true
+
 cargo-check-benches:
   stage:                           test
   <<:                              *docker-env

.maintain/clippy.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env sh
+
+# Script for building only the WASM binary of the given project.
+
+set -e
+
+SKIP_WASM_BUILD=1 cargo +nightly clippy -- \
+-A clippy::all \
+-D clippy::correctness \
+-A clippy::if-same-then-else \
+-A clippy::clone-double-ref

client/executor/src/wasm_runtime.rs

@@ -306,6 +306,7 @@ pub fn create_wasm_runtime_with_code(
 			//
 			// We drop the cache_path here to silence warnings that cache_path is not used if
 			// compiling without the `wasmtime` flag.
+			#[allow(clippy::drop_copy)]
 			drop(cache_path);
 
 			sc_executor_wasmi::create_runtime(

client/executor/wasmtime/src/instance_wrapper.rs

@@ -399,6 +399,7 @@ impl InstanceWrapper {
 	/// See `[memory_as_slice]`. In addition to those requirements, since a mutable reference is
 	/// returned it must be ensured that only one mutable and no shared references to memory exists
 	/// at the same time.
+	#[allow(clippy::mut_from_ref)]
 	unsafe fn memory_as_slice_mut(&self) -> &mut [u8] {
 		let ptr = self.memory.data_ptr();
 		let len = self.memory.data_size();

client/network/src/block_request_handler.rs

@@ -85,6 +85,7 @@ struct SeenRequestsKey<B: BlockT> {
 	support_multiple_justifications: bool,
 }
 
+#[allow(clippy::derive_hash_xor_eq)]
 impl<B: BlockT> Hash for SeenRequestsKey<B> {
 	fn hash<H: Hasher>(&self, state: &mut H) {
 		self.peer.hash(state);

client/network/src/state_request_handler.rs

@@ -78,6 +78,7 @@ struct SeenRequestsKey<B: BlockT> {
 	start: Vec<u8>,
 }
 
+#[allow(clippy::derive_hash_xor_eq)]
 impl<B: BlockT> Hash for SeenRequestsKey<B> {
 	fn hash<H: Hasher>(&self, state: &mut H) {
 		self.peer.hash(state);