syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! Up until MIR building, this attribute has absolutely no effect. The `mir!` macro is a normal
context_before: //!
context_after: //! decl macro that expands like any other, and the code goes through parsing, name resolution and