use rustc_session::lint::builtin::{UNUSED_MACROS, UNUSED_MACRO_RULES};

use rustc_session::lint::BuiltinLintDiag;

use rustc_session::parse::feature_err;

use rustc_span::edit_distance::edit_distance;

use rustc_span::edition::Edition;

use rustc_span::hygiene::{self, ExpnData, ExpnKind, LocalExpnId};

use rustc_span::hygiene::{AstPass, MacroKind};

}

if res == Res::NonMacroAttr(NonMacroAttrKind::Tool)

&& path.segments.len() >= 2

&& path.segments[0].ident.name == sym::diagnostic

&& path.segments[1].ident.name != sym::on_unimplemented

&& let [namespace, attribute, ..] = &*path.segments

&& namespace.ident.name == sym::diagnostic

&& attribute.ident.name != sym::on_unimplemented

{

self.tcx.sess.psess.buffer_lint(

let distance =

edit_distance(attribute.ident.name.as_str(), sym::on_unimplemented.as_str(), 5);

let help = if distance.is_some() {

BuiltinLintDiag::MaybeTypo { span: attribute.span(), name: sym::on_unimplemented }

} else {

BuiltinLintDiag::Normal

};

self.tcx.sess.psess.buffer_lint_with_diagnostic(

UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,

path.segments[1].span(),

attribute.span(),

node_id,

"unknown diagnostic attribute",

help,

);

}