#[trace] attribute suppresses dead_code warnings for unused functions

[drmingdrmer]

Summary

The #[fastrace::trace] attribute suppresses Rust's dead_code lint, causing the compiler to not warn about unused functions.

Reproduction

struct Foo;

impl Foo {
    // No warning - even though this function is never called
    #[fastrace::trace]
    async fn unused_function(&self) -> i32 {
        42
    }
}

Expected behavior

The compiler should warn: method 'unused_function' is never used.

Actual behavior

No warning. Removing #[fastrace::trace] causes the warning to appear.

Environment

• fastrace 0.7.14 with enable feature enabled
• rustc 1.94.0-nightly (f52090008 2025-12-10)