Function rustc_expand::mbe::macro_check::check_nested_occurrences

fn check_nested_occurrences(
    sess: &ParseSess, 
    node_id: NodeId, 
    tts: &[TokenTree], 
    macros: &Stack<'_, MacroState<'_>>, 
    binders: &FxHashMap<MacroRulesNormalizedIdent, BinderInfo>, 
    ops: &Stack<'_, KleeneToken>, 
    valid: &mut bool
)

Checks tts as part of the RHS of a macro definition, tries to recognize nested macro definitions, and sets valid to false in case of errors.

Arguments:

• sess is used to emit diagnostics and lints
• node_id is used to emit lints
• tts is checked as part of a RHS and may contain macro definitions
• macros is the stack of possible outer macros
• binders contains the binders of the associated LHS
• ops is the stack of Kleene operators from the RHS
• valid is set in case of errors