Struct Frame 

pub struct Frame {
    pub closure: Gc<LuaClosure>,
    pub base: u32,
    pub pc: u32,
    pub func_slot: u32,
    pub n_varargs: u32,
    pub nresults: i32,
    pub hook_oldpc: u32,
    pub from_c: bool,
    pub tm: Option<&'static str>,
    pub is_hook: bool,
    pub tailcalls: u32,
}

An activation record on a thread’s call stack. Pure data (closure handle + stack offsets), so it lives in runtime where the GC can trace a suspended coroutine’s frames.

Fields

closure: Gc<LuaClosure>

Currently executing closure.

base: u32

stack index of register 0

pc: u32

Program counter (index into closure.proto.code).

func_slot: u32

stack slot of the function (results land here)

n_varargs: u32

number of extra (vararg) arguments, living on the stack just below base at func_slot+1 .. func_slot+1+n_varargs (PUC CallInfo.u.l.nextraargs). OP_VARARG/OP_VARGIDX read them there; a named vararg only materializes a heap table when it is written / escapes / is _ENV.

nresults: i32

results expected by the caller (-1 = all)

hook_oldpc: u32

pc the line hook last observed in this frame (PUC CallInfo oldpc); u32::MAX on a fresh frame so its first instruction fires a line event

from_c: bool

true if this Lua frame was entered across a C boundary (call_value: a metamethod, pcall, __close handler, or a coroutine body). Debug level traversal (debug.getinfo/traceback) inserts a synthetic C frame below it.

tm: Option<&'static str>

the metamethod event this frame is handling (e.g. “close” for a __close handler call), so debug.traceback/getinfo can name it “metamethod ‘close’” (PUC CallInfo.u.l.tm/luaG_funcnamefromtm).

is_hook: bool

true when this frame is the hook function itself (PUC sets CIST_HOOKED). debug.getinfo(1).namewhat returns "hook" for it.

tailcalls: u32

PUC ci->u.l.tailcalls — how many tail calls have collapsed into this activation slot. Each OP_TailCall chain adds one. 5.1 lua_getstack reports a synthetic CIST_TAIL level per count (so a deeply tail-recursive function shows tailcalls extra levels between itself and its real caller — 5.1 db.lua :372 walks getinfo(2..lim) and expects each to be "tail"). The 5.2+ istailcall boolean is tailcalls > 0.

Trait Implementations

impl Clone for Frame

fn clone(&self) -> Frame

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Frame