rustc_expand::mbe::macro_check

Function check_meta_variables

Source 
pub(super) fn check_meta_variables(
    psess: &ParseSess,
    node_id: NodeId,
    lhs: &TokenTree,
    rhs: &TokenTree,
) -> Result<(), ErrorGuaranteed>
Expand description

Checks that meta-variables are used correctly in one rule of a macro definition.

Arguments:

  • psess is used to emit diagnostics and lints
  • node_id is used to emit lints
  • lhs and rhs represent the rule