코드 객체
*********

코드 객체는 CPython 구현의 저수준 세부 사항입니다. 각 객체는 아직 함수
에 묶여 있지 않은 실행 가능한 코드 덩어리를 나타냅니다.

type PyCodeObject

   코드 객체를 설명하는 데 사용되는 객체의 C 구조체. 이 형의 필드는 언
   제든지 변경될 수 있습니다.

PyTypeObject PyCode_Type

   이것은 파이썬 코드 객체를 나타내는 "PyTypeObject"의 인스턴스입니다.

int PyCode_Check(PyObject *co)

   *co*가 코드 객체면 참을 반환합니다. 이 함수는 항상 성공합니다.

Py_ssize_t PyCode_GetNumFree(PyCodeObject *co)

   코드 객체에 있는 *자유 (클로저) 변수*의 개수를 반환합니다.

int PyUnstable_Code_GetFirstFree(PyCodeObject *co)

   *이것은 불안정 API. It may change without warning in minor
   releases.*

   Return the position of the first *free (closure) variable* in a
   code object.

   버전 3.13에서 변경: Renamed from "PyCode_GetFirstFree" as part of
   Unstable C API. The old name is deprecated, but will remain
   available until the signature changes again.

PyCodeObject *PyUnstable_Code_New(int argcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, PyObject *qualname, int firstlineno, PyObject *linetable, PyObject *exceptiontable)

   *이것은 불안정 API. It may change without warning in minor
   releases.*

   새 코드 객체를 반환합니다. 프레임을 만들기 위해 더미 코드 객체가 필
   요하면, 대신 "PyCode_NewEmpty()"를 사용하십시오.

   Since the definition of the bytecode changes often, calling
   "PyUnstable_Code_New()" directly can bind you to a precise Python
   version.

   The many arguments of this function are inter-dependent in complex
   ways, meaning that subtle changes to values are likely to result in
   incorrect execution or VM crashes. Use this function only with
   extreme care.

   버전 3.11에서 변경: Added "qualname" and "exceptiontable"
   parameters.

   버전 3.12에서 변경: Renamed from "PyCode_New" as part of Unstable C
   API. The old name is deprecated, but will remain available until
   the signature changes again.

PyCodeObject *PyUnstable_Code_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, PyObject *qualname, int firstlineno, PyObject *linetable, PyObject *exceptiontable)

   *이것은 불안정 API. It may change without warning in minor
   releases.*

   "PyUnstable_Code_New()"와 비슷하지만, 위치 전용 인자를 위한 추가
   "posonlyargcount"가 있습니다. "PyUnstable_Code_New"에 적용되는 것과
   같은 주의 사항이 이 함수에도 적용됩니다.

   Added in version 3.8: as "PyCode_NewWithPosOnlyArgs"

   버전 3.11에서 변경: Added "qualname" and  "exceptiontable"
   parameters.

   버전 3.12에서 변경: Renamed to
   "PyUnstable_Code_NewWithPosOnlyArgs". The old name is deprecated,
   but will remain available until the signature changes again.

PyCodeObject *PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
    *반환값: 새 참조.*

   지정된 파일명, 함수명 및 첫 번째 줄 번호를 갖는 새 빈 코드 객체를
   반환합니다. 결과 코드 객체를 실행하면 "Exception"을 발생시킵니다.

int PyCode_Addr2Line(PyCodeObject *co, int byte_offset)

   Return the line number of the instruction that occurs on or before
   "byte_offset" and ends after it. If you just need the line number
   of a frame, use "PyFrame_GetLineNumber()" instead.

   For efficiently iterating over the line numbers in a code object,
   use **the API described in PEP 626**.

int PyCode_Addr2Location(PyObject *co, int byte_offset, int *start_line, int *start_column, int *end_line, int *end_column)

   Sets the passed "int" pointers to the source code line and column
   numbers for the instruction at "byte_offset". Sets the value to "0"
   when information is not available for any particular element.

   Returns "1" if the function succeeds and 0 otherwise.

   Added in version 3.11.

PyObject *PyCode_GetCode(PyCodeObject *co)

   Equivalent to the Python code "getattr(co, 'co_code')". Returns a
   strong reference to a "PyBytesObject" representing the bytecode in
   a code object. On error, "NULL" is returned and an exception is
   raised.

   This "PyBytesObject" may be created on-demand by the interpreter
   and does not necessarily represent the bytecode actually executed
   by CPython. The primary use case for this function is debuggers and
   profilers.

   Added in version 3.11.

PyObject *PyCode_GetVarnames(PyCodeObject *co)

   Equivalent to the Python code "getattr(co, 'co_varnames')". Returns
   a new reference to a "PyTupleObject" containing the names of the
   local variables. On error, "NULL" is returned and an exception is
   raised.

   Added in version 3.11.

PyObject *PyCode_GetCellvars(PyCodeObject *co)

   Equivalent to the Python code "getattr(co, 'co_cellvars')". Returns
   a new reference to a "PyTupleObject" containing the names of the
   local variables that are referenced by nested functions. On error,
   "NULL" is returned and an exception is raised.

   Added in version 3.11.

PyObject *PyCode_GetFreevars(PyCodeObject *co)

   Equivalent to the Python code "getattr(co, 'co_freevars')". Returns
   a new reference to a "PyTupleObject" containing the names of the
   *free (closure) variables*. On error, "NULL" is returned and an
   exception is raised.

   Added in version 3.11.

int PyCode_AddWatcher(PyCode_WatchCallback callback)

   Register *callback* as a code object watcher for the current
   interpreter. Return an ID which may be passed to
   "PyCode_ClearWatcher()". In case of error (e.g. no more watcher IDs
   available), return "-1" and set an exception.

   Added in version 3.12.

int PyCode_ClearWatcher(int watcher_id)

   Clear watcher identified by *watcher_id* previously returned from
   "PyCode_AddWatcher()" for the current interpreter. Return "0" on
   success, or "-1" and set an exception on error (e.g. if the given
   *watcher_id* was never registered.)

   Added in version 3.12.

type PyCodeEvent

   Enumeration of possible code object watcher events: -
   "PY_CODE_EVENT_CREATE" - "PY_CODE_EVENT_DESTROY"

   Added in version 3.12.

typedef int (*PyCode_WatchCallback)(PyCodeEvent event, PyCodeObject *co)

   Type of a code object watcher callback function.

   If *event* is "PY_CODE_EVENT_CREATE", then the callback is invoked
   after *co* has been fully initialized. Otherwise, the callback is
   invoked before the destruction of *co* takes place, so the prior
   state of *co* can be inspected.

   If *event* is "PY_CODE_EVENT_DESTROY", taking a reference in the
   callback to the about-to-be-destroyed code object will resurrect it
   and prevent it from being freed at this time. When the resurrected
   object is destroyed later, any watcher callbacks active at that
   time will be called again.

   Users of this API should not rely on internal runtime
   implementation details. Such details may include, but are not
   limited to, the exact order and timing of creation and destruction
   of code objects. While changes in these details may result in
   differences observable by watchers (including whether a callback is
   invoked or not), it does not change the semantics of the Python
   code being executed.

   If the callback sets an exception, it must return "-1"; this
   exception will be printed as an unraisable exception using
   "PyErr_WriteUnraisable()". Otherwise it should return "0".

   There may already be a pending exception set on entry to the
   callback. In this case, the callback should return "0" with the
   same exception still set. This means the callback may not call any
   other API that can set an exception unless it saves and clears the
   exception state first, and restores it before returning.

   Added in version 3.12.

PyObject *PyCode_Optimize(PyObject *code, PyObject *consts, PyObject *names, PyObject *lnotab_obj)

   This is a *soft deprecated* function that does nothing.

   Prior to Python 3.10, this function would perform basic
   optimizations to a code object.

   버전 3.10에서 변경: This function now does nothing.


Code Object Flags
*****************

Code objects contain a bit-field of flags, which can be retrieved as
the "co_flags" Python attribute (for example using
"PyObject_GetAttrString()"), and set using a *flags* argument to
"PyUnstable_Code_New()" and similar functions.

Flags whose names start with "CO_FUTURE_" correspond to features
normally selectable by future statements. These flags can be used in
"PyCompilerFlags.cf_flags". Note that many "CO_FUTURE_" flags are
mandatory in current versions of Python, and setting them has no
effect.

The following flags are available. For their meaning, see the linked
documentation of their Python equivalents.

+----------------------------------------------------+----------------------------------------------------+
| Flag                                               | Meaning                                            |
|====================================================|====================================================|
| CO_OPTIMIZED                                       | "inspect.CO_OPTIMIZED"                             |
+----------------------------------------------------+----------------------------------------------------+
| CO_NEWLOCALS                                       | "inspect.CO_NEWLOCALS"                             |
+----------------------------------------------------+----------------------------------------------------+
| CO_VARARGS                                         | "inspect.CO_VARARGS"                               |
+----------------------------------------------------+----------------------------------------------------+
| CO_VARKEYWORDS                                     | "inspect.CO_VARKEYWORDS"                           |
+----------------------------------------------------+----------------------------------------------------+
| CO_NESTED                                          | "inspect.CO_NESTED"                                |
+----------------------------------------------------+----------------------------------------------------+
| CO_GENERATOR                                       | "inspect.CO_GENERATOR"                             |
+----------------------------------------------------+----------------------------------------------------+
| CO_COROUTINE                                       | "inspect.CO_COROUTINE"                             |
+----------------------------------------------------+----------------------------------------------------+
| CO_ITERABLE_COROUTINE                              | "inspect.CO_ITERABLE_COROUTINE"                    |
+----------------------------------------------------+----------------------------------------------------+
| CO_ASYNC_GENERATOR                                 | "inspect.CO_ASYNC_GENERATOR"                       |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_DIVISION                                 | no effect ("__future__.division")                  |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_ABSOLUTE_IMPORT                          | no effect ("__future__.absolute_import")           |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_WITH_STATEMENT                           | no effect ("__future__.with_statement")            |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_PRINT_FUNCTION                           | no effect ("__future__.print_function")            |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_UNICODE_LITERALS                         | no effect ("__future__.unicode_literals")          |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_GENERATOR_STOP                           | no effect ("__future__.generator_stop")            |
+----------------------------------------------------+----------------------------------------------------+
| CO_FUTURE_ANNOTATIONS                              | "__future__.annotations"                           |
+----------------------------------------------------+----------------------------------------------------+


Extra information
*****************

To support low-level extensions to frame evaluation, such as external
just-in-time compilers, it is possible to attach arbitrary extra data
to code objects.

These functions are part of the unstable C API tier: this
functionality is a CPython implementation detail, and the API may
change without deprecation warnings.

Py_ssize_t PyUnstable_Eval_RequestCodeExtraIndex(freefunc free)

   *이것은 불안정 API. It may change without warning in minor
   releases.*

   Return a new opaque index value used to adding data to code
   objects.

   You generally call this function once (per interpreter) and use the
   result with "PyCode_GetExtra" and "PyCode_SetExtra" to manipulate
   data on individual code objects.

   If *free* is not "NULL": when a code object is deallocated, *free*
   will be called on non-"NULL" data stored under the new index. Use
   "Py_DecRef()" when storing "PyObject".

   Added in version 3.6: as "_PyEval_RequestCodeExtraIndex"

   버전 3.12에서 변경: Renamed to
   "PyUnstable_Eval_RequestCodeExtraIndex". The old private name is
   deprecated, but will be available until the API changes.

int PyUnstable_Code_GetExtra(PyObject *code, Py_ssize_t index, void **extra)

   *이것은 불안정 API. It may change without warning in minor
   releases.*

   Set *extra* to the extra data stored under the given index. Return
   0 on success. Set an exception and return -1 on failure.

   If no data was set under the index, set *extra* to "NULL" and
   return 0 without setting an exception.

   Added in version 3.6: as "_PyCode_GetExtra"

   버전 3.12에서 변경: Renamed to "PyUnstable_Code_GetExtra". The old
   private name is deprecated, but will be available until the API
   changes.

int PyUnstable_Code_SetExtra(PyObject *code, Py_ssize_t index, void *extra)

   *이것은 불안정 API. It may change without warning in minor
   releases.*

   Set the extra data stored under the given index to *extra*. Return
   0 on success. Set an exception and return -1 on failure.

   Added in version 3.6: as "_PyCode_SetExtra"

   버전 3.12에서 변경: Renamed to "PyUnstable_Code_SetExtra". The old
   private name is deprecated, but will be available until the API
   changes.
