internal: init: allow nonstandard_style warnings for generated code

Allows `nonstandard_style` lint on accessors/values generated as local
variables by `init!`/`pin_init!`.

Since the same warning will be reported by the compiler on the struct
definition, having the extra warning for the generated accessor/value 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

@@ -40,6 +40,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   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.
+- `init!` and `pin_init!` no longer produce `non_snake_case` warnings if field names
+  are not of snake case. Warnings on the struct definition are unaffected.
 
 ## [0.0.10] - 2025-08-19
 

internal/src/init.rs

@@ -245,7 +245,14 @@ fn init_fields(
                     // Setting the span of `value_ident` to `value`'s span improves error messages
                     // when the type of `value` is wrong.
                     value_ident.set_span(value.span());
-                    quote!(let #value_ident = #value;)
+                    quote! {
+                        // Allow `non_snake_case` since the same warning is going to be reported for
+                        // the struct field. Evaluate `#value` first so that user code warnings are not
+                        // suppressed.
+                        let __value_tmp = #value;
+                        #[allow(non_snake_case)]
+                        let #value_ident = __value_tmp;
+                    }
                 });
                 // Again span for better diagnostics
                 let write = quote_spanned!(ident.span()=> ::core::ptr::write);
@@ -273,7 +280,9 @@ fn init_fields(
                         unsafe { #write(&raw mut (*#slot).#ident, #value_ident) };
                     }
                     #(#cfgs)*
-                    #[allow(unused_variables)]
+                    // Allow `non_snake_case` since the same warning is going to be reported for
+                    // the struct field.
+                    #[allow(unused_variables, non_snake_case)]
                     let #ident = #accessor;
                 }
             }
@@ -325,7 +334,9 @@ fn init_fields(
                         #value_init
                     }
                     #(#cfgs)*
-                    #[allow(unused_variables)]
+                    // Allow `non_snake_case` since the same warning is going to be reported for
+                    // the struct field.
+                    #[allow(unused_variables, non_snake_case)]
                     let #ident = #accessor;
                 }
             }