<function name="attach" parent="jit" type="libraryfunc"> <description> You can attach callbacks to a number of compiler events with jit.attach. The callback can be called: * when a function has been compiled to bytecode ("bc"); * when trace recording starts or stops ("trace"); * as a trace is being recorded ("record"); * or when a trace exits through a side exit ("texit"). Set a callback with jit.attach(callback, "event") and clear the same callback with jit.attach(callback)⤶ * when a function has been compiled to bytecode (`"bc"`); * when trace recording starts or stops (`"trace"`); * as a trace is being recorded (`"record"`); * or when a trace exits through a side exit (`"texit"`). Set a callback with `jit.attach(callback, "event")` and clear the same callback with `jit.attach(callback)`⤶ <warning>This function isn't officially documented on LuaJIT wiki, use it at your own risk.</warning> <warning>Using these constantly (especially bytecode) can be very performance heavy due to the constant stream of data being compiled at a time.</warning> </description> <realm>Shared and Menu</realm> <args> <arg name="callback" type="function">The callback function. The arguments passed to the callback depend on the event being reported: * "bc":⤶ <page>function</page> func - The function that's just been recorded ⤶ ⤶ ⤶ * "trace":⤶ <page>string</page> what - description of the trace event: "flush", "start", "stop", "abort". Available for all events. ⤶ ⤶ <page>number</page> tr - The trace number. Not available for flush. ⤶ ⤶ <page>function</page> func - The function being traced. Available for start and abort. ⤶ ⤶ <page>number</page> pc - The program counter - the bytecode number of the function being recorded (if this a Lua function). Available for start and abort. ⤶ ⤶ <page>number</page> otr - start: the parent trace number if this is a side trace, abort: abort code⤶ ⤶ ⤶ <page>string</page> oex - start: the exit number for the parent trace, abort: abort reason (string)⤶ ⤶ ⤶ ⤶ * "record":⤶ <page>number</page> tr - The trace number. Not available for flush. ⤶ ⤶ <page>function</page> func - The function being traced. Available for start and abort.⤶ ⤶ ⤶ <page>number</page> pc - The program counter - the bytecode number of the function being recorded (if this a Lua function). Available for start and abort.⤶ ⤶ ⤶ <page>number</page> depth - The depth of the inlining of the current bytecode.⤶ ⤶ ⤶ ⤶ * "texit":⤶ <page>number</page> tr - The trace number. Not available for flush.⤶ ⤶ ⤶ <page>number</page> ex - The exit number⤶ ⤶ ⤶ <page>number</page> ngpr - The number of general-purpose and floating point registers that are active at the exit.⤶ ⤶ ⤶ <page>number</page> nfpr - The number of general-purpose and floating point registers that are active at the exit.</arg>⤶ * `"bc"`:⤶ * <page>function</page> **func** - The function that's just been recorded * `"trace"`:⤶ * <page>string</page> **what** - description of the trace event: "flush", "start", "stop", "abort". Available for all events.⤶ * <page>number</page> **tr** - The trace number. Not available for flush. * <page>function</page> **func** - The function being traced. Available for start and abort.⤶ * <page>number</page> **pc** - The program counter - the bytecode number of the function being recorded (if this a Lua function). Available for start and abort. * <page>number</page> **otr** - start: the parent trace number if this is a side trace, abort: abort code⤶ * <page>string</page> **oex** - start: the exit number for the parent trace, abort: abort reason (string) * `"record"`:⤶ * <page>number</page> **tr** - The trace number. Not available for flush. * <page>function</page> **func** - The function being traced. Available for start and abort.⤶ * <page>number</page> **pc** - The program counter - the bytecode number of the function being recorded (if this a Lua function). Available for start and abort.⤶ * <page>number</page> **depth** - The depth of the inlining of the current bytecode.⤶ * `"texit"`:⤶ * <page>number</page> **tr** - The trace number. Not available for flush.⤶ * <page>number</page> **ex** - The exit number⤶ * <page>number</page> **ngpr** - The number of general-purpose and floating point registers that are active at the exit. * <page>number</page> **nfpr** - The number of general-purpose and floating point registers that are active at the exit.⤶ </arg>⤶ <arg name="event" type="string">The event to hook into.</arg> </args> </function>