Tested with the following changes:

diff --git a/examples/big_struct_in_place.rs b/examples/big_struct_in_place.rs
index 80f89b5..5525cae 100644
--- a/examples/big_struct_in_place.rs
+++ b/examples/big_struct_in_place.rs
@@ -13,8 +13,8 @@ pub struct BigStruct {
     a: u64,
     b: u64,
     c: u64,
-    d: u64,
-    managed_buf: ManagedBuf,
+    NONSTANDARD_D: u64,
+    MANAGED_BUF: ManagedBuf,
 }

 #[derive(Debug)]
@@ -37,8 +37,8 @@ fn main() {
             a: 7,
             b: 186,
             c: 7789,
-            d: 34,
-            managed_buf <- ManagedBuf::new(),
+            NONSTANDARD_D: 34,
+            MANAGED_BUF <- ManagedBuf::new(),
         }))
         .unwrap();
         println!("{}", core::mem::size_of_val(&*buf));

Output before the patch:

$ cargo run --example big_struct_in_place
[...]
error: structure field `NONSTANDARD_D` should have a snake case name
  --> examples/big_struct_in_place.rs:16:5
   |
16 |     NONSTANDARD_D: u64,
   |     ^^^^^^^^^^^^^ help: convert the identifier to snake case: `nonstandard_d`
   |
   = note: `-D non-snake-case` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(non_snake_case)]`

error: structure field `MANAGED_BUF` should have a snake case name
  --> examples/big_struct_in_place.rs:17:5
   |
17 |     MANAGED_BUF: ManagedBuf,
   |     ^^^^^^^^^^^ help: convert the identifier to snake case: `managed_buf`

error: variable `NONSTANDARD_D` should have a snake case name
  --> examples/big_struct_in_place.rs:40:28
   |
40 |             NONSTANDARD_D: 34,
   |                            ^^ help: convert the identifier to snake case: `nonstandard_d`

error: variable `NONSTANDARD_D` should have a snake case name
  --> examples/big_struct_in_place.rs:40:13
   |
40 |             NONSTANDARD_D: 34,
   |             ^^^^^^^^^^^^^ help: convert the identifier to snake case: `nonstandard_d`

error: variable `MANAGED_BUF` should have a snake case name
  --> examples/big_struct_in_place.rs:41:13
   |
41 |             MANAGED_BUF <- ManagedBuf::new(),
   |             ^^^^^^^^^^^ help: convert the identifier to snake case: `managed_buf`

error: could not compile `pin-init` (example "big_struct_in_place") due to 5 previous errors

Output after the patch:

$ cargo run --example big_struct_in_place
[...]
error: structure field `NONSTANDARD_D` should have a snake case name
  --> examples/big_struct_in_place.rs:16:5
   |
16 |     NONSTANDARD_D: u64,
   |     ^^^^^^^^^^^^^ help: convert the identifier to snake case: `nonstandard_d`
   |
   = note: `-D non-snake-case` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(non_snake_case)]`

error: structure field `MANAGED_BUF` should have a snake case name
  --> examples/big_struct_in_place.rs:17:5
   |
17 |     MANAGED_BUF: ManagedBuf,
   |     ^^^^^^^^^^^ help: convert the identifier to snake case: `managed_buf`

error: could not compile `pin-init` (example "big_struct_in_place") due to 2 previous errors

I am still quite new to the process of contributing to Rust-For-Linux. Please let me know if I've made any mistakes or if I've missed something.

Please add a test for this

Does something like this look okay?

I think what you want is not a compile_fail test, but rather than the code (with allow on the struct definition side), compiles to completion without warnings? So this should just be a test in src/tests.

Right, that sounds like a better approach.

I've amended the existing test commit to keep the branch clean, hopefully that's okay: 2d194be

So this should just be a test in src/tests.

I put the test under the existing tests directory in the crate root, I hope that's what you meant. If you specifically wanted a new directory in src, I'm happy to move it.

Two more things:

1. The CI failure seems unrelated, running rustup run 1.78 cargo check on main produces the same error for me.
2. Would you like me to add a changelog entry for this fix?

main works fine for me. Did you not add RUSTC_BOOTSTRAP=1? Please do add a changelog entry.

Sorry for the delay - I just pushed a few more commits. Hopefully that covers everything now.

I kept the new commits separate, so that it is easier to see the diffs. Please let me know if you want them squashed.

I've squashed the commits as suggested. I didn't keep the fixup commits for the most recent round of reviews (there wasn't a nice way to split them per comment but also per commit they should be folded into), so I'll list the changes here:

This sentence doesn't need to be here; this is an integral part of the test.

This comment has been removed.

actually, could you update code to use the specific lint, such as non_snake_case for suppression?

Done. Only non_snake_case warnings were generated by the macros (in the test cases that exist at the moment) so this was pretty much a search and replace.

Also, could you squash the changelog update into the same commit that update the code please.

Done.

You'd also probably want a line about #[pin_data], to mention that lints can now be properly suppressed where it couldn't previously.

Added a line for #[pin_data] in the changelog.

Hmm, actually this can cause lints to be suppressed on #value, which is provided by the user.

Nice catch. I've split up the evaluation of user code and assignment to a local variable, only suppressing warnings for the latter. I've also modified the test to prove this works as intended now.

I've rebased the code with accessor rework landed. I've noticed when trying to apply that there's some style issues with the commits (same as the other PR) about the tags.

Reported-by should followed immediately by Closes. Also, the #[pin_data] commit is currently using the wrong commit hash (given that the code is introduced very early, I wouldn't bother looking up the correct hash, would remove the fixes tag instead).

Thanks for letting me know. I've edited both commits to follow the tag guidelines and removed the Fixes tag on the #[pin_data] commit.