field_reassign_with_default triggers inside `macro_rules!` macro

Summary

For a macro, it might not always be practical to replace a field reassign after (default) initialization with a struct literal. In the case of this test, the only purpose of the macro being tested is providing struct-update like syntax but using assignments under the hood.

Lint Name

field_reassign_with_default

Reproducer

I tried this code:

use assign::assign; // version 1.1.1

#[derive(Default)]
struct SomeStruct {
    a: u32,
    b: Option<f32>,
    c: Option<u64>,
}

let res = assign!(SomeStruct::default(), {
    a: 5,
    b: None,
});

I saw this happen (condensed form of full output):

warning: field assignment outside of initializer for an instance created with Default::default()
note: consider initializing the variable with `tests::SomeStruct { b: assign!(SomeStruct::default(), {
              b,
              c: 1.into(),
          }), c: 1.into(), ..Default::default() }` and removing relevant reassignments

I expected to see this happen: No warnings

Version

rustc 1.59.0-nightly (e95e084a1 2021-12-19)
binary: rustc
commit-hash: e95e084a14870a718c712936ab5a8f8cd0159485
commit-date: 2021-12-19
host: x86_64-unknown-linux-gnu
release: 1.59.0-nightly
LLVM version: 13.0.0

Additional Labels

No response

Start at the field_reassign_with_default lint and reproduce the report with the assign crate example from docs.rs (assign/lib.rs lines 142-145). Trace how the macro_rules! expansion is analyzed; done means the reproducer emits no warning.