syntax_data: {"ast_node_type":"other","tokens":[{"end":15,"kind":"keyword","start":0,"text":"#[track_caller]"}]}
source_snippet: #[track_caller]
context_before: /// This diagnostic is only a warning and *does not cause compilation to fail*.
context_after: pub fn feature_warn(sess: &Session, feature: Symbol, span: Span, explain: &'static str) {