chore: add clippy CI tests

run cargo clippy for all targets

(backport <#4411>)
(cherry picked from commit bea4d1b)

Author: nyurik

Cargo.toml

@@ -150,3 +150,25 @@ members = [
     "ctest",
     "libc-test",
 ]
+
+#
+# TODO: These should be renamed as `[workspace.lints.*]` once MSRV is abve 1.64
+#       This way all crates can use it with `[lints] workspace=true` section
+#
+
+[lints.rust]
+# TODO: make ident usage consistent in each file
+unused_qualifications = "allow"
+
+[lints.clippy]
+# TODO: all these are default lints and should probably be fixed
+identity_op = "allow"
+if_same_then_else = "allow"
+missing_safety_doc = "allow"
+non_minimal_cfg = "allow"
+precedence = "allow"
+redundant_field_names = "allow"
+redundant_static_lifetimes = "allow"
+unnecessary_cast = "allow"
+unused_unit = "allow"
+zero_ptr = "allow"

ci/style.sh

@@ -4,6 +4,9 @@ set -eux
 
 [ -n "${CI:-}" ] && check="--check"
 
+# TODO: for some reason using `--workspace` validates a lot of generated code in ./target/** dir
+cargo clippy -p libc@1.0.0-alpha.1 -p ctest --all-targets -- -D warnings
+
 cargo test --manifest-path libc-test/Cargo.toml --test style -- --nocapture
 
 command -v rustfmt

ci/verify-build.sh

@@ -44,9 +44,13 @@ test_target() {
     # The basic command that is run each time
     cmd="cargo +$rust build --target $target"
 
+    # The basic clippy command
+    clippy_cmd="cargo +$rust clippy --all-targets --target $target"
+
     if [ "${no_dist}" != "0" ]; then
         # If we can't download a `core`, we need to build it
         cmd="$cmd -Zbuild-std=core,alloc"
+        clippy_cmd="$clippy_cmd -Zbuild-std=core,alloc"
 
         # FIXME: With `build-std` feature, `compiler_builtins` emits a lof of lint warnings.
         RUSTFLAGS="${RUSTFLAGS:-} -Aimproper_ctypes_definitions"
@@ -67,6 +71,9 @@ test_target() {
         done
     fi
 
+    # Run cargo clippy first
+    $clippy_cmd
+
     # Test with expected combinations of features
     $cmd
     $cmd --features const-extern-fn

libc-test/Cargo.toml

@@ -104,3 +104,26 @@ harness = true
 name = "style_tests"
 path = "test/style_tests.rs"
 harness = true
+
+#
+# TODO: These should be moved to the root Cargo.toml as `[workspace.lints.*]` once MSRV is abve 1.64
+#       replace it with `[lints] workspace=true`
+#
+
+[lints.rust]
+# TODO: make ident usage consistent in each file
+unused_qualifications = "allow"
+
+[lints.clippy]
+# TODO: fix these, and enable pedantic lints with needed exceptions
+needless_return = "allow"
+comparison_to_empty = "allow"
+unused_io_amount = "allow"
+write_with_newline = "allow"
+needless_borrows_for_generic_args = "allow"
+only_used_in_recursion = "allow"
+match_like_matches_macro = "allow"
+useless_format = "allow"
+wildcard_in_or_patterns = "allow"
+nonminimal_bool = "allow"
+match_single_binding = "allow"