internal: suppress non_snake_case lint in #[pin_data]

Allows `non_snake_case` lint on struct fields generated by `#[pin_data]`.

Since the same warning will be reported by the compiler on the struct
definition, having extra warnings for the generated code is unnecessary
and confusing.

Reported-by: Gary Guo <gary@garyguo.net>
Link: #125
Closes: https://lore.kernel.org/rust-for-linux/DGTBJBIVFZ2K.2F1ZEFGY0G7NK@garyguo.net/
Fixes: db96c51 ("add references to previously initialized fields")
Signed-off-by: Mirko Adzic <adzicmirko97@gmail.com>

Author: Mirko-A

CHANGELOG.md

@@ -39,6 +39,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Corrected `T: Sized` bounds to `T: ?Sized` in the generated `PinnedDrop`
   check by `#[pin_data]`.
+- `#[pin_data]` no longer produces additional `non_snake_case` warnings if field names
+  are not of snake case. Standard field definition warnings are unaffected.
 
 ## [0.0.10] - 2025-08-19
 

internal/src/pin_data.rs

@@ -175,7 +175,10 @@ fn generate_unpin_impl(
     quote! {
         // This struct will be used for the unpin analysis. It is needed, because only structurally
         // pinned fields are relevant whether the struct should implement `Unpin`.
-        #[allow(dead_code)] // The fields below are never used.
+        #[allow(
+            dead_code, // The fields below are never used.
+            non_snake_case // The warning will be emitted on the struct definition.
+        )]
         struct __Unpin #generics_with_pin_lt
         #where_token
             #predicates
@@ -309,7 +312,9 @@ fn generate_projections(
     let docs = format!(" Pin-projections of [`{ident}`]");
     quote! {
         #[doc = #docs]
-        #[allow(dead_code)]
+        // Allow `non_snake_case` since the same warning will be emitted on
+        // the struct definition.
+        #[allow(dead_code, non_snake_case)]
         #[doc(hidden)]
         #vis struct #projection #generics_with_pin_lt
             #whr
@@ -382,6 +387,9 @@ fn generate_the_pin_data(
                 /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
                 ///   memory.
                 #(#attrs)*
+                // Allow `non_snake_case` since the same warning will be emitted on
+                // the struct definition.
+                #[allow(non_snake_case)]
                 #[inline(always)]
                 #vis unsafe fn #field_name(
                     self,

tests/ui/expand/many_generics.expanded.rs

@@ -13,7 +13,7 @@ where
     _pin: PhantomPinned,
 }
 /// Pin-projections of [`Foo`]
-#[allow(dead_code)]
+#[allow(dead_code, non_snake_case)]
 #[doc(hidden)]
 struct FooProjection<'__pin, 'a, 'b: 'a, T: Bar<'b> + ?Sized + 'a, const SIZE: usize = 0>
 where
@@ -98,6 +98,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn array(
             self,
@@ -114,6 +115,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn r(
             self,
@@ -130,6 +132,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn _pin(
             self,
@@ -157,7 +160,7 @@ const _: () = {
             }
         }
     }
-    #[allow(dead_code)]
+    #[allow(dead_code, non_snake_case)]
     struct __Unpin<'__pin, 'a, 'b: 'a, T: Bar<'b> + ?Sized + 'a, const SIZE: usize = 0>
     where
         T: Bar<'a, 1>,

tests/ui/expand/pin-data.expanded.rs

@@ -5,7 +5,7 @@ struct Foo {
     _pin: PhantomPinned,
 }
 /// Pin-projections of [`Foo`]
-#[allow(dead_code)]
+#[allow(dead_code, non_snake_case)]
 #[doc(hidden)]
 struct FooProjection<'__pin> {
     array: &'__pin mut [u8; 1024 * 1024],
@@ -62,6 +62,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn array(
             self,
@@ -78,6 +79,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn _pin(
             self,
@@ -97,7 +99,7 @@ const _: () = {
             }
         }
     }
-    #[allow(dead_code)]
+    #[allow(dead_code, non_snake_case)]
     struct __Unpin<'__pin> {
         __phantom_pin: ::pin_init::__internal::PhantomInvariantLifetime<'__pin>,
         __phantom: ::pin_init::__internal::PhantomInvariant<Foo>,

tests/ui/expand/pinned_drop.expanded.rs

@@ -5,7 +5,7 @@ struct Foo {
     _pin: PhantomPinned,
 }
 /// Pin-projections of [`Foo`]
-#[allow(dead_code)]
+#[allow(dead_code, non_snake_case)]
 #[doc(hidden)]
 struct FooProjection<'__pin> {
     array: &'__pin mut [u8; 1024 * 1024],
@@ -62,6 +62,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn array(
             self,
@@ -78,6 +79,7 @@ const _: () = {
         /// - `(*slot).#field_name` is properly aligned.
         /// - `(*slot).#field_name` points to uninitialized and exclusively accessed
         ///   memory.
+        #[allow(non_snake_case)]
         #[inline(always)]
         unsafe fn _pin(
             self,
@@ -97,7 +99,7 @@ const _: () = {
             }
         }
     }
-    #[allow(dead_code)]
+    #[allow(dead_code, non_snake_case)]
     struct __Unpin<'__pin> {
         __phantom_pin: ::pin_init::__internal::PhantomInvariantLifetime<'__pin>,
         __phantom: ::pin_init::__internal::PhantomInvariant<Foo>,