rustc/tests/ui/lint/unused/unused-doc-comments-for-macros.rs

#![deny(unused_doc_comments)]
#![feature(rustc_attrs)]

macro_rules! foo { () => {}; }

fn main() {
    /// line1 //~ ERROR: unused doc comment
    /// line2
    /// line3
    foo!();

    // Ensure we still detect another doc-comment block.
    /// line1 //~ ERROR: unused doc comment
    /// line2
    /// line3
    foo!();
}