Function rustc_expand::mbe::macro_check::check_meta_variables

pub(in mbe) fn check_meta_variables(
    sess: &ParseSess, 
    node_id: NodeId, 
    span: Span, 
    lhses: &[TokenTree], 
    rhses: &[TokenTree]
) -> bool

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

Arguments:

• sess is used to emit diagnostics and lints
• node_id is used to emit lints
• span is used when no spans are available
• lhses and rhses should have the same length and represent the macro definition