blob: be766beae58a7dbda8015fea52139d43812fd156 [file] [log] [blame]
#include <torch/csrc/dynamo/cpython_defs.h>
#ifdef _WIN32
#define unlikely(x) (x)
#else
#define unlikely(x) __builtin_expect((x), 0)
#endif
#define CHECK(cond) \
if (unlikely(!(cond))) { \
fprintf(stderr, "DEBUG CHECK FAILED: %s:%d\n", __FILE__, __LINE__); \
abort(); \
} else { \
}
// NOTE: all `assert`s below are converted to `CHECK`s
#if IS_PYTHON_3_11_PLUS
#define Py_BUILD_CORE
#include <internal/pycore_pystate.h>
#define NEED_OPCODE_TABLES // To get _PyOpcode_Deopt
#include <internal/pycore_opcode.h>
#undef NEED_OPCODE_TABLES
#undef Py_BUILD_CORE
#include <internal/pycore_frame.h>
// As a simple way to reduce the impact of ABI changes on the CPython side, this check forces
// us to manually re-check that the function didn't change on the next major version
#if PY_VERSION_HEX >= 0x030C0000 // 3.12
#error "Please ensure that the functions below still match the CPython implementation for 3.12"
#endif
// https://github.com/python/cpython/blob/a7715ccfba5b86ab09f86ec56ac3755c93b46b48/Objects/frameobject.c#L1079
static int
THP_PyFrame_OpAlreadyRan(_PyInterpreterFrame *frame, int opcode, int oparg)
{
// This only works when opcode is a non-quickened form:
CHECK(_PyOpcode_Deopt[opcode] == opcode);
int check_oparg = 0;
for (_Py_CODEUNIT *instruction = _PyCode_CODE(frame->f_code);
instruction < frame->prev_instr; instruction++)
{
int check_opcode = _PyOpcode_Deopt[_Py_OPCODE(*instruction)];
check_oparg |= _Py_OPARG(*instruction);
if (check_opcode == opcode && check_oparg == oparg) {
return 1;
}
if (check_opcode == EXTENDED_ARG) {
check_oparg <<= 8;
}
else {
check_oparg = 0;
}
instruction += _PyOpcode_Caches[check_opcode];
}
return 0;
}
// https://github.com/python/cpython/blob/a7715ccfba5b86ab09f86ec56ac3755c93b46b48/Objects/frameobject.c#L1182
int
THP_PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame) {
/* Merge fast locals into f->f_locals */
PyObject *locals;
PyObject **fast;
PyCodeObject *co;
locals = frame->f_locals;
if (locals == NULL) {
locals = frame->f_locals = PyDict_New();
if (locals == NULL)
return -1;
}
co = frame->f_code;
fast = _PyFrame_GetLocalsArray(frame);
// COPY_FREE_VARS has no quickened forms, so no need to use _PyOpcode_Deopt
// here:
int lasti = _PyInterpreterFrame_LASTI(frame);
if (lasti < 0 && _Py_OPCODE(_PyCode_CODE(co)[0]) == COPY_FREE_VARS) {
/* Free vars have not been initialized -- Do that */
PyCodeObject *co = frame->f_code;
PyObject *closure = frame->f_func->func_closure;
int offset = co->co_nlocals + co->co_nplaincellvars;
for (int i = 0; i < co->co_nfreevars; ++i) {
PyObject *o = PyTuple_GET_ITEM(closure, i);
Py_INCREF(o);
frame->localsplus[offset + i] = o;
}
// COPY_FREE_VARS doesn't have inline CACHEs, either:
frame->prev_instr = _PyCode_CODE(frame->f_code);
}
for (int i = 0; i < co->co_nlocalsplus; i++) {
_PyLocals_Kind kind = _PyLocals_GetKind(co->co_localspluskinds, i);
/* If the namespace is unoptimized, then one of the
following cases applies:
1. It does not contain free variables, because it
uses import * or is a top-level namespace.
2. It is a class namespace.
We don't want to accidentally copy free variables
into the locals dict used by the class.
*/
if (kind & CO_FAST_FREE && !(co->co_flags & CO_OPTIMIZED)) {
continue;
}
PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
PyObject *value = fast[i];
if (frame->stacktop) {
if (kind & CO_FAST_FREE) {
// The cell was set by COPY_FREE_VARS.
CHECK(value != NULL && PyCell_Check(value));
value = PyCell_GET(value);
}
else if (kind & CO_FAST_CELL) {
// Note that no *_DEREF ops can happen before MAKE_CELL
// executes. So there's no need to duplicate the work
// that MAKE_CELL would otherwise do later, if it hasn't
// run yet.
if (value != NULL) {
if (PyCell_Check(value) &&
THP_PyFrame_OpAlreadyRan(frame, MAKE_CELL, i)) {
// (likely) MAKE_CELL must have executed already.
value = PyCell_GET(value);
}
// (likely) Otherwise it it is an arg (kind & CO_FAST_LOCAL),
// with the initial value set when the frame was created...
// (unlikely) ...or it was set to some initial value by
// an earlier call to PyFrame_LocalsToFast().
}
}
}
else {
CHECK(value == NULL);
}
if (value == NULL) {
if (PyObject_DelItem(locals, name) != 0) {
if (PyErr_ExceptionMatches(PyExc_KeyError)) {
PyErr_Clear();
}
else {
return -1;
}
}
}
else {
if (PyObject_SetItem(locals, name, value) != 0) {
return -1;
}
}
}
return 0;
}
// e.g. COPY_FIELD(op, o, globals) becomes
// PY_XINCREF((o)->func_globals);
// (op)->func_globals = (o)->func_globals;
#define COPY_FIELD(f1, f2, field) \
Py_XINCREF((f2)->func_##field); \
(f1)->func_##field = (f2)->func_##field;
// Not actually copied from CPython, but loosely based on
// https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Objects/funcobject.c
// Makes a new PyFunctionObject copy of `o`, but with the code object fields
// determined from `code`.
// Ensure that all fields defined in the PyFunctionObject struct in
// https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Include/cpython/funcobject.h
// are accounted for.
PyFunctionObject *
_PyFunction_CopyWithNewCode(PyFunctionObject *o, PyCodeObject* code)
{
PyFunctionObject *op = PyObject_GC_New(PyFunctionObject, &PyFunction_Type);
if (op == NULL) {
return NULL;
}
Py_XINCREF(code);
op->func_code = (PyObject *) code;
Py_XINCREF(code->co_name);
op->func_name = code->co_name;
Py_XINCREF(code->co_qualname);
op->func_qualname = code->co_qualname;
COPY_FIELD(op, o, globals);
COPY_FIELD(op, o, builtins);
COPY_FIELD(op, o, defaults);
COPY_FIELD(op, o, kwdefaults);
COPY_FIELD(op, o, closure);
COPY_FIELD(op, o, doc);
COPY_FIELD(op, o, dict);
COPY_FIELD(op, o, weakreflist);
COPY_FIELD(op, o, module);
COPY_FIELD(op, o, annotations);
op->vectorcall = o->vectorcall;
op->func_version = o->func_version;
PyObject_GC_Track(op);
return op;
}
// From https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Objects/frameobject.c#L1020
PyFrameObject*
THP_PyFrame_New_NoTrack(PyCodeObject *code)
{
// DYNAMO: commented out
// CALL_STAT_INC(frame_objects_created);
int slots = code->co_nlocalsplus + code->co_stacksize;
PyFrameObject *f = PyObject_GC_NewVar(PyFrameObject, &PyFrame_Type, slots);
if (f == NULL) {
return NULL;
}
f->f_back = NULL;
f->f_trace = NULL;
f->f_trace_lines = 1;
f->f_trace_opcodes = 0;
f->f_fast_as_locals = 0;
f->f_lineno = 0;
return f;
}
// From https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Python/frame.c#L27
PyFrameObject *
THP_PyFrame_MakeAndSetFrameObject(_PyInterpreterFrame *frame)
{
CHECK(frame->frame_obj == NULL);
PyObject *error_type, *error_value, *error_traceback;
PyErr_Fetch(&error_type, &error_value, &error_traceback);
PyFrameObject *f = THP_PyFrame_New_NoTrack(frame->f_code);
if (f == NULL) {
Py_XDECREF(error_type);
Py_XDECREF(error_value);
Py_XDECREF(error_traceback);
return NULL;
}
PyErr_Restore(error_type, error_value, error_traceback);
if (frame->frame_obj) {
// GH-97002: How did we get into this horrible situation? Most likely,
// allocating f triggered a GC collection, which ran some code that
// *also* created the same frame... while we were in the middle of
// creating it! See test_sneaky_frame_object in test_frame.py for a
// concrete example.
//
// Regardless, just throw f away and use that frame instead, since it's
// already been exposed to user code. It's actually a bit tricky to do
// this, since we aren't backed by a real _PyInterpreterFrame anymore.
// Just pretend that we have an owned, cleared frame so frame_dealloc
// doesn't make the situation worse:
f->f_frame = (_PyInterpreterFrame *)f->_f_frame_data;
f->f_frame->owner = FRAME_CLEARED;
f->f_frame->frame_obj = f;
Py_DECREF(f);
return frame->frame_obj;
}
CHECK(frame->owner != FRAME_OWNED_BY_FRAME_OBJECT);
CHECK(frame->owner != FRAME_CLEARED);
f->f_frame = frame;
frame->frame_obj = f;
return f;
}
// From https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Include/internal/pycore_frame.h#L163
static inline PyFrameObject *
THP_PyFrame_GetFrameObject(_PyInterpreterFrame *frame)
{
CHECK(!_PyFrame_IsIncomplete(frame));
PyFrameObject *res = frame->frame_obj;
if (res != NULL) {
return res;
}
return THP_PyFrame_MakeAndSetFrameObject(frame);
}
// From https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Python/frame.c#L79
static void
THP_take_ownership(PyFrameObject *f, _PyInterpreterFrame *frame)
{
CHECK(frame->owner != FRAME_OWNED_BY_FRAME_OBJECT);
CHECK(frame->owner != FRAME_CLEARED);
Py_ssize_t size = ((char*)&frame->localsplus[frame->stacktop]) - (char *)frame;
memcpy((_PyInterpreterFrame *)f->_f_frame_data, frame, size);
frame = (_PyInterpreterFrame *)f->_f_frame_data;
f->f_frame = frame;
frame->owner = FRAME_OWNED_BY_FRAME_OBJECT;
if (_PyFrame_IsIncomplete(frame)) {
// This may be a newly-created generator or coroutine frame. Since it's
// dead anyways, just pretend that the first RESUME ran:
PyCodeObject *code = frame->f_code;
frame->prev_instr = _PyCode_CODE(code) + code->_co_firsttraceable;
}
CHECK(!_PyFrame_IsIncomplete(frame));
CHECK(f->f_back == NULL);
_PyInterpreterFrame *prev = frame->previous;
while (prev && _PyFrame_IsIncomplete(prev)) {
prev = prev->previous;
}
if (prev) {
/* Link PyFrameObjects.f_back and remove link through _PyInterpreterFrame.previous */
PyFrameObject *back = THP_PyFrame_GetFrameObject(prev);
if (back == NULL) {
/* Memory error here. */
CHECK(PyErr_ExceptionMatches(PyExc_MemoryError));
/* Nothing we can do about it */
PyErr_Clear();
}
else {
f->f_back = (PyFrameObject *)Py_NewRef(back);
}
frame->previous = NULL;
}
// DYNAMO: use public GC functions instead of internal ones
if (!PyObject_GC_IsTracked((PyObject *) f)) {
PyObject_GC_Track((PyObject *) f);
}
}
// From https://github.com/python/cpython/blob/e715da6db1d1d70cd779dc48e1ba8110c51cc1bf/Python/frame.c#L120
void
THP_PyFrame_Clear(_PyInterpreterFrame *frame)
{
/* It is the responsibility of the owning generator/coroutine
* to have cleared the enclosing generator, if any. */
CHECK(frame->owner != FRAME_OWNED_BY_GENERATOR ||
_PyFrame_GetGenerator(frame)->gi_frame_state == FRAME_CLEARED);
// GH-99729: Clearing this frame can expose the stack (via finalizers). It's
// crucial that this frame has been unlinked, and is no longer visible:
CHECK(_PyThreadState_GET()->cframe->current_frame != frame);
if (frame->frame_obj) {
PyFrameObject *f = frame->frame_obj;
frame->frame_obj = NULL;
if (Py_REFCNT(f) > 1) {
THP_take_ownership(f, frame);
Py_DECREF(f);
return;
}
Py_DECREF(f);
}
CHECK(frame->stacktop >= 0);
for (int i = 0; i < frame->stacktop; i++) {
Py_XDECREF(frame->localsplus[i]);
}
Py_XDECREF(frame->frame_obj);
Py_XDECREF(frame->f_locals);
Py_DECREF(frame->f_func);
Py_DECREF(frame->f_code);
}
#endif