debug.getupvalues

Returns the upvalues captured by a closure or by a running stack frame, as a table.

debug.getupvalues(func: function | number): {any}

New to upvalues? Learn more here.

Give it a number instead of a function and it reads a stack level, exactly like debug.getupvalue.

Most commonly used to snapshot a closure’s captured state in one call: find an unknown function with getgc, dump its upvalues, and read off the objects it is holding before touching it.

Parameters

Parameter	Type	Description
func	function or number	The closure to read.

Returns

{any} - an array-style table of the captured upvalues, in the order they were captured. A closure with no upvalues returns an empty table, never nil.

Aliases

• getupvalues

Example

A closure with two upvalues, dumped with pairs:

Example 1

local getupvalues = debug.getupvalues(function(...) end)

Give it a number instead of a function and it reads a stack level, exactly like debug.getupvalue.