[derive] Suppress non_camel_case_types...

...in derive-generated code.

Closes #2051

gherrit-pr-id: If3dbedcccd338435b5aa72dd724caaf9447b1baa

zerocopy-derive/src/enum.rs

@@ -35,7 +35,7 @@ pub(crate) fn generate_tag_enum(repr: &EnumRepr, data: &DataEnum) -> TokenStream
 
     quote! {
         #repr
-        #[allow(dead_code)]
+        #[allow(dead_code, non_camel_case_types)]
         enum ___ZerocopyTag {
             #(#variants,)*
         }

zerocopy-derive/src/lib.rs

@@ -1339,6 +1339,9 @@ fn impl_block<D: DataExt>(
         // TODO(#553): Add a test that generates a warning when
         // `#[allow(deprecated)]` isn't present.
         #[allow(deprecated)]
+        // While there are not currently any warnings that this suppresses (that
+        // we're aware of), it's good future-proofing hygiene.
+        #[automatically_derived]
         unsafe impl < #(#params),* > #trait_path for #type_ident < #(#param_idents),* >
         where
             #(#bounds,)*

zerocopy-derive/tests/enum_try_from_bytes.rs

@@ -626,3 +626,19 @@ fn test_trivial_is_bit_valid() {
     util_assert_not_impl_any!(FooU8: imp::FromBytes);
     util::test_trivial_is_bit_valid::<FooU8>();
 }
+
+#[deny(non_camel_case_types)]
+mod issue_2051 {
+    use super::*;
+
+    // Test that the `non_camel_case_types` lint isn't triggered by generated code.
+    // Prevents regressions of #2051.
+    #[repr(u32)]
+    #[derive(imp::TryFromBytes)]
+    #[allow(non_camel_case_types)]
+    pub enum Code {
+        I32_ADD,
+        I32_SUB,
+        I32_MUL,
+    }
+}