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2768 lines (2534 loc) · 84.6 KB
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Copy pathceval.c
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2768 lines (2534 loc) · 84.6 KB
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/* Execute compiled code */
#define _PY_INTERPRETER
#include "Python.h"
#include "pycore_abstract.h" // _PyIndex_Check()
#include "pycore_call.h" // _PyObject_FastCallDictTstate()
#include "pycore_ceval.h" // _PyEval_SignalAsyncExc()
#include "pycore_code.h"
#include "pycore_function.h"
#include "pycore_intrinsics.h"
#include "pycore_long.h" // _PyLong_GetZero()
#include "pycore_instruments.h"
#include "pycore_object.h" // _PyObject_GC_TRACK()
#include "pycore_moduleobject.h" // PyModuleObject
#include "pycore_opcode.h" // EXTRA_CASES
#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
#include "pycore_pymem.h" // _PyMem_IsPtrFreed()
#include "pycore_pystate.h" // _PyInterpreterState_GET()
#include "pycore_range.h" // _PyRangeIterObject
#include "pycore_sliceobject.h" // _PyBuildSlice_ConsumeRefs
#include "pycore_sysmodule.h" // _PySys_Audit()
#include "pycore_tuple.h" // _PyTuple_ITEMS()
#include "pycore_typeobject.h" // _PySuper_Lookup()
#include "pycore_emscripten_signal.h" // _Py_CHECK_EMSCRIPTEN_SIGNALS
#include "pycore_dict.h"
#include "dictobject.h"
#include "pycore_frame.h"
#include "frameobject.h" // _PyInterpreterFrame_GetLine
#include "opcode.h"
#include "pydtrace.h"
#include "setobject.h"
#include "structmember.h" // struct PyMemberDef, T_OFFSET_EX
#include <ctype.h>
#include <stdbool.h>
#ifdef Py_DEBUG
/* For debugging the interpreter: */
# define LLTRACE 1 /* Low-level trace feature */
#endif
#if !defined(Py_BUILD_CORE)
# error "ceval.c must be build with Py_BUILD_CORE define for best performance"
#endif
#if !defined(Py_DEBUG) && !defined(Py_TRACE_REFS)
// GH-89279: The MSVC compiler does not inline these static inline functions
// in PGO build in _PyEval_EvalFrameDefault(), because this function is over
// the limit of PGO, and that limit cannot be configured.
// Define them as macros to make sure that they are always inlined by the
// preprocessor.
#undef Py_DECREF
#define Py_DECREF(arg) \
do { \
PyObject *op = _PyObject_CAST(arg); \
if (_Py_IsImmortal(op)) { \
break; \
} \
_Py_DECREF_STAT_INC(); \
if (--op->ob_refcnt == 0) { \
destructor dealloc = Py_TYPE(op)->tp_dealloc; \
(*dealloc)(op); \
} \
} while (0)
#undef Py_XDECREF
#define Py_XDECREF(arg) \
do { \
PyObject *xop = _PyObject_CAST(arg); \
if (xop != NULL) { \
Py_DECREF(xop); \
} \
} while (0)
#undef Py_IS_TYPE
#define Py_IS_TYPE(ob, type) \
(_PyObject_CAST(ob)->ob_type == (type))
#undef _Py_DECREF_SPECIALIZED
#define _Py_DECREF_SPECIALIZED(arg, dealloc) \
do { \
PyObject *op = _PyObject_CAST(arg); \
if (_Py_IsImmortal(op)) { \
break; \
} \
_Py_DECREF_STAT_INC(); \
if (--op->ob_refcnt == 0) { \
destructor d = (destructor)(dealloc); \
d(op); \
} \
} while (0)
#endif
// GH-89279: Similar to above, force inlining by using a macro.
#if defined(_MSC_VER) && SIZEOF_INT == 4
#define _Py_atomic_load_relaxed_int32(ATOMIC_VAL) (assert(sizeof((ATOMIC_VAL)->_value) == 4), *((volatile int*)&((ATOMIC_VAL)->_value)))
#else
#define _Py_atomic_load_relaxed_int32(ATOMIC_VAL) _Py_atomic_load_relaxed(ATOMIC_VAL)
#endif
#ifdef LLTRACE
static void
dump_stack(_PyInterpreterFrame *frame, PyObject **stack_pointer)
{
PyObject **stack_base = _PyFrame_Stackbase(frame);
PyObject *exc = PyErr_GetRaisedException();
printf(" stack=[");
for (PyObject **ptr = stack_base; ptr < stack_pointer; ptr++) {
if (ptr != stack_base) {
printf(", ");
}
if (PyObject_Print(*ptr, stdout, 0) != 0) {
PyErr_Clear();
printf("<%s object at %p>",
Py_TYPE(*ptr)->tp_name, (void *)(*ptr));
}
}
printf("]\n");
fflush(stdout);
PyErr_SetRaisedException(exc);
}
static void
lltrace_instruction(_PyInterpreterFrame *frame,
PyObject **stack_pointer,
_Py_CODEUNIT *next_instr)
{
/* This dump_stack() operation is risky, since the repr() of some
objects enters the interpreter recursively. It is also slow.
So you might want to comment it out. */
dump_stack(frame, stack_pointer);
int oparg = next_instr->op.arg;
int opcode = next_instr->op.code;
const char *opname = _PyOpcode_OpName[opcode];
assert(opname != NULL);
int offset = (int)(next_instr - _PyCode_CODE(frame->f_code));
if (HAS_ARG((int)_PyOpcode_Deopt[opcode])) {
printf("%d: %s %d\n", offset * 2, opname, oparg);
}
else {
printf("%d: %s\n", offset * 2, opname);
}
fflush(stdout);
}
static void
lltrace_resume_frame(_PyInterpreterFrame *frame)
{
PyObject *fobj = frame->f_funcobj;
if (frame->owner == FRAME_OWNED_BY_CSTACK ||
fobj == NULL ||
!PyFunction_Check(fobj)
) {
printf("\nResuming frame.\n");
return;
}
PyFunctionObject *f = (PyFunctionObject *)fobj;
PyObject *exc = PyErr_GetRaisedException();
PyObject *name = f->func_qualname;
if (name == NULL) {
name = f->func_name;
}
printf("\nResuming frame");
if (name) {
printf(" for ");
if (PyObject_Print(name, stdout, 0) < 0) {
PyErr_Clear();
}
}
if (f->func_module) {
printf(" in module ");
if (PyObject_Print(f->func_module, stdout, 0) < 0) {
PyErr_Clear();
}
}
printf("\n");
fflush(stdout);
PyErr_SetRaisedException(exc);
}
#endif
static void monitor_raise(PyThreadState *tstate,
_PyInterpreterFrame *frame,
_Py_CODEUNIT *instr);
static int monitor_stop_iteration(PyThreadState *tstate,
_PyInterpreterFrame *frame,
_Py_CODEUNIT *instr);
static void monitor_unwind(PyThreadState *tstate,
_PyInterpreterFrame *frame,
_Py_CODEUNIT *instr);
static void monitor_handled(PyThreadState *tstate,
_PyInterpreterFrame *frame,
_Py_CODEUNIT *instr, PyObject *exc);
static void monitor_throw(PyThreadState *tstate,
_PyInterpreterFrame *frame,
_Py_CODEUNIT *instr);
static PyObject * import_name(PyThreadState *, _PyInterpreterFrame *,
PyObject *, PyObject *, PyObject *);
static PyObject * import_from(PyThreadState *, PyObject *, PyObject *);
static void format_exc_check_arg(PyThreadState *, PyObject *, const char *, PyObject *);
static void format_exc_unbound(PyThreadState *tstate, PyCodeObject *co, int oparg);
static int check_args_iterable(PyThreadState *, PyObject *func, PyObject *vararg);
static int check_except_type_valid(PyThreadState *tstate, PyObject* right);
static int check_except_star_type_valid(PyThreadState *tstate, PyObject* right);
static void format_kwargs_error(PyThreadState *, PyObject *func, PyObject *kwargs);
static void format_awaitable_error(PyThreadState *, PyTypeObject *, int);
static int get_exception_handler(PyCodeObject *, int, int*, int*, int*);
static _PyInterpreterFrame *
_PyEvalFramePushAndInit(PyThreadState *tstate, PyFunctionObject *func,
PyObject *locals, PyObject* const* args,
size_t argcount, PyObject *kwnames);
static _PyInterpreterFrame *
_PyEvalFramePushAndInit_Ex(PyThreadState *tstate, PyFunctionObject *func,
PyObject *locals, Py_ssize_t nargs, PyObject *callargs, PyObject *kwargs);
static void
_PyEvalFrameClearAndPop(PyThreadState *tstate, _PyInterpreterFrame *frame);
#define UNBOUNDLOCAL_ERROR_MSG \
"cannot access local variable '%s' where it is not associated with a value"
#define UNBOUNDFREE_ERROR_MSG \
"cannot access free variable '%s' where it is not associated with a" \
" value in enclosing scope"
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
int
Py_GetRecursionLimit(void)
{
PyInterpreterState *interp = _PyInterpreterState_GET();
return interp->ceval.recursion_limit;
}
void
Py_SetRecursionLimit(int new_limit)
{
PyInterpreterState *interp = _PyInterpreterState_GET();
interp->ceval.recursion_limit = new_limit;
for (PyThreadState *p = interp->threads.head; p != NULL; p = p->next) {
int depth = p->py_recursion_limit - p->py_recursion_remaining;
p->py_recursion_limit = new_limit;
p->py_recursion_remaining = new_limit - depth;
}
}
/* The function _Py_EnterRecursiveCallTstate() only calls _Py_CheckRecursiveCall()
if the recursion_depth reaches recursion_limit. */
int
_Py_CheckRecursiveCall(PyThreadState *tstate, const char *where)
{
#ifdef USE_STACKCHECK
if (PyOS_CheckStack()) {
++tstate->c_recursion_remaining;
_PyErr_SetString(tstate, PyExc_MemoryError, "Stack overflow");
return -1;
}
#endif
if (tstate->recursion_headroom) {
if (tstate->c_recursion_remaining < -50) {
/* Overflowing while handling an overflow. Give up. */
Py_FatalError("Cannot recover from stack overflow.");
}
}
else {
if (tstate->c_recursion_remaining <= 0) {
tstate->recursion_headroom++;
_PyErr_Format(tstate, PyExc_RecursionError,
"maximum recursion depth exceeded%s",
where);
tstate->recursion_headroom--;
++tstate->c_recursion_remaining;
return -1;
}
}
return 0;
}
static const binaryfunc binary_ops[] = {
[NB_ADD] = PyNumber_Add,
[NB_AND] = PyNumber_And,
[NB_FLOOR_DIVIDE] = PyNumber_FloorDivide,
[NB_LSHIFT] = PyNumber_Lshift,
[NB_MATRIX_MULTIPLY] = PyNumber_MatrixMultiply,
[NB_MULTIPLY] = PyNumber_Multiply,
[NB_REMAINDER] = PyNumber_Remainder,
[NB_OR] = PyNumber_Or,
[NB_POWER] = _PyNumber_PowerNoMod,
[NB_RSHIFT] = PyNumber_Rshift,
[NB_SUBTRACT] = PyNumber_Subtract,
[NB_TRUE_DIVIDE] = PyNumber_TrueDivide,
[NB_XOR] = PyNumber_Xor,
[NB_INPLACE_ADD] = PyNumber_InPlaceAdd,
[NB_INPLACE_AND] = PyNumber_InPlaceAnd,
[NB_INPLACE_FLOOR_DIVIDE] = PyNumber_InPlaceFloorDivide,
[NB_INPLACE_LSHIFT] = PyNumber_InPlaceLshift,
[NB_INPLACE_MATRIX_MULTIPLY] = PyNumber_InPlaceMatrixMultiply,
[NB_INPLACE_MULTIPLY] = PyNumber_InPlaceMultiply,
[NB_INPLACE_REMAINDER] = PyNumber_InPlaceRemainder,
[NB_INPLACE_OR] = PyNumber_InPlaceOr,
[NB_INPLACE_POWER] = _PyNumber_InPlacePowerNoMod,
[NB_INPLACE_RSHIFT] = PyNumber_InPlaceRshift,
[NB_INPLACE_SUBTRACT] = PyNumber_InPlaceSubtract,
[NB_INPLACE_TRUE_DIVIDE] = PyNumber_InPlaceTrueDivide,
[NB_INPLACE_XOR] = PyNumber_InPlaceXor,
};
// PEP 634: Structural Pattern Matching
// Return a tuple of values corresponding to keys, with error checks for
// duplicate/missing keys.
static PyObject*
match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
{
assert(PyTuple_CheckExact(keys));
Py_ssize_t nkeys = PyTuple_GET_SIZE(keys);
if (!nkeys) {
// No keys means no items.
return PyTuple_New(0);
}
PyObject *seen = NULL;
PyObject *dummy = NULL;
PyObject *values = NULL;
PyObject *get = NULL;
// We use the two argument form of map.get(key, default) for two reasons:
// - Atomically check for a key and get its value without error handling.
// - Don't cause key creation or resizing in dict subclasses like
// collections.defaultdict that define __missing__ (or similar).
int meth_found = _PyObject_GetMethod(map, &_Py_ID(get), &get);
if (get == NULL) {
goto fail;
}
seen = PySet_New(NULL);
if (seen == NULL) {
goto fail;
}
// dummy = object()
dummy = _PyObject_CallNoArgs((PyObject *)&PyBaseObject_Type);
if (dummy == NULL) {
goto fail;
}
values = PyTuple_New(nkeys);
if (values == NULL) {
goto fail;
}
for (Py_ssize_t i = 0; i < nkeys; i++) {
PyObject *key = PyTuple_GET_ITEM(keys, i);
if (PySet_Contains(seen, key) || PySet_Add(seen, key)) {
if (!_PyErr_Occurred(tstate)) {
// Seen it before!
_PyErr_Format(tstate, PyExc_ValueError,
"mapping pattern checks duplicate key (%R)", key);
}
goto fail;
}
PyObject *args[] = { map, key, dummy };
PyObject *value = NULL;
if (meth_found) {
value = PyObject_Vectorcall(get, args, 3, NULL);
}
else {
value = PyObject_Vectorcall(get, &args[1], 2, NULL);
}
if (value == NULL) {
goto fail;
}
if (value == dummy) {
// key not in map!
Py_DECREF(value);
Py_DECREF(values);
// Return None:
values = Py_NewRef(Py_None);
goto done;
}
PyTuple_SET_ITEM(values, i, value);
}
// Success:
done:
Py_DECREF(get);
Py_DECREF(seen);
Py_DECREF(dummy);
return values;
fail:
Py_XDECREF(get);
Py_XDECREF(seen);
Py_XDECREF(dummy);
Py_XDECREF(values);
return NULL;
}
// Extract a named attribute from the subject, with additional bookkeeping to
// raise TypeErrors for repeated lookups. On failure, return NULL (with no
// error set). Use _PyErr_Occurred(tstate) to disambiguate.
static PyObject*
match_class_attr(PyThreadState *tstate, PyObject *subject, PyObject *type,
PyObject *name, PyObject *seen)
{
assert(PyUnicode_CheckExact(name));
assert(PySet_CheckExact(seen));
if (PySet_Contains(seen, name) || PySet_Add(seen, name)) {
if (!_PyErr_Occurred(tstate)) {
// Seen it before!
_PyErr_Format(tstate, PyExc_TypeError,
"%s() got multiple sub-patterns for attribute %R",
((PyTypeObject*)type)->tp_name, name);
}
return NULL;
}
PyObject *attr = PyObject_GetAttr(subject, name);
if (attr == NULL && _PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
_PyErr_Clear(tstate);
}
return attr;
}
// On success (match), return a tuple of extracted attributes. On failure (no
// match), return NULL. Use _PyErr_Occurred(tstate) to disambiguate.
static PyObject*
match_class(PyThreadState *tstate, PyObject *subject, PyObject *type,
Py_ssize_t nargs, PyObject *kwargs)
{
if (!PyType_Check(type)) {
const char *e = "called match pattern must be a class";
_PyErr_Format(tstate, PyExc_TypeError, e);
return NULL;
}
assert(PyTuple_CheckExact(kwargs));
// First, an isinstance check:
if (PyObject_IsInstance(subject, type) <= 0) {
return NULL;
}
// So far so good:
PyObject *seen = PySet_New(NULL);
if (seen == NULL) {
return NULL;
}
PyObject *attrs = PyList_New(0);
if (attrs == NULL) {
Py_DECREF(seen);
return NULL;
}
// NOTE: From this point on, goto fail on failure:
PyObject *match_args = NULL;
// First, the positional subpatterns:
if (nargs) {
int match_self = 0;
match_args = PyObject_GetAttrString(type, "__match_args__");
if (match_args) {
if (!PyTuple_CheckExact(match_args)) {
const char *e = "%s.__match_args__ must be a tuple (got %s)";
_PyErr_Format(tstate, PyExc_TypeError, e,
((PyTypeObject *)type)->tp_name,
Py_TYPE(match_args)->tp_name);
goto fail;
}
}
else if (_PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
_PyErr_Clear(tstate);
// _Py_TPFLAGS_MATCH_SELF is only acknowledged if the type does not
// define __match_args__. This is natural behavior for subclasses:
// it's as if __match_args__ is some "magic" value that is lost as
// soon as they redefine it.
match_args = PyTuple_New(0);
match_self = PyType_HasFeature((PyTypeObject*)type,
_Py_TPFLAGS_MATCH_SELF);
}
else {
goto fail;
}
assert(PyTuple_CheckExact(match_args));
Py_ssize_t allowed = match_self ? 1 : PyTuple_GET_SIZE(match_args);
if (allowed < nargs) {
const char *plural = (allowed == 1) ? "" : "s";
_PyErr_Format(tstate, PyExc_TypeError,
"%s() accepts %d positional sub-pattern%s (%d given)",
((PyTypeObject*)type)->tp_name,
allowed, plural, nargs);
goto fail;
}
if (match_self) {
// Easy. Copy the subject itself, and move on to kwargs.
PyList_Append(attrs, subject);
}
else {
for (Py_ssize_t i = 0; i < nargs; i++) {
PyObject *name = PyTuple_GET_ITEM(match_args, i);
if (!PyUnicode_CheckExact(name)) {
_PyErr_Format(tstate, PyExc_TypeError,
"__match_args__ elements must be strings "
"(got %s)", Py_TYPE(name)->tp_name);
goto fail;
}
PyObject *attr = match_class_attr(tstate, subject, type, name,
seen);
if (attr == NULL) {
goto fail;
}
PyList_Append(attrs, attr);
Py_DECREF(attr);
}
}
Py_CLEAR(match_args);
}
// Finally, the keyword subpatterns:
for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(kwargs); i++) {
PyObject *name = PyTuple_GET_ITEM(kwargs, i);
PyObject *attr = match_class_attr(tstate, subject, type, name, seen);
if (attr == NULL) {
goto fail;
}
PyList_Append(attrs, attr);
Py_DECREF(attr);
}
Py_SETREF(attrs, PyList_AsTuple(attrs));
Py_DECREF(seen);
return attrs;
fail:
// We really don't care whether an error was raised or not... that's our
// caller's problem. All we know is that the match failed.
Py_XDECREF(match_args);
Py_DECREF(seen);
Py_DECREF(attrs);
return NULL;
}
static int do_raise(PyThreadState *tstate, PyObject *exc, PyObject *cause);
static int exception_group_match(
PyObject* exc_value, PyObject *match_type,
PyObject **match, PyObject **rest);
static int unpack_iterable(PyThreadState *, PyObject *, int, int, PyObject **);
PyObject *
PyEval_EvalCode(PyObject *co, PyObject *globals, PyObject *locals)
{
PyThreadState *tstate = _PyThreadState_GET();
if (locals == NULL) {
locals = globals;
}
PyObject *builtins = _PyEval_BuiltinsFromGlobals(tstate, globals); // borrowed ref
if (builtins == NULL) {
return NULL;
}
PyFrameConstructor desc = {
.fc_globals = globals,
.fc_builtins = builtins,
.fc_name = ((PyCodeObject *)co)->co_name,
.fc_qualname = ((PyCodeObject *)co)->co_name,
.fc_code = co,
.fc_defaults = NULL,
.fc_kwdefaults = NULL,
.fc_closure = NULL
};
PyFunctionObject *func = _PyFunction_FromConstructor(&desc);
if (func == NULL) {
return NULL;
}
EVAL_CALL_STAT_INC(EVAL_CALL_LEGACY);
PyObject *res = _PyEval_Vector(tstate, func, locals, NULL, 0, NULL);
Py_DECREF(func);
return res;
}
/* Interpreter main loop */
PyObject *
PyEval_EvalFrame(PyFrameObject *f)
{
/* Function kept for backward compatibility */
PyThreadState *tstate = _PyThreadState_GET();
return _PyEval_EvalFrame(tstate, f->f_frame, 0);
}
PyObject *
PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
{
PyThreadState *tstate = _PyThreadState_GET();
return _PyEval_EvalFrame(tstate, f->f_frame, throwflag);
}
#include "ceval_macros.h"
int _Py_CheckRecursiveCallPy(
PyThreadState *tstate)
{
if (tstate->recursion_headroom) {
if (tstate->py_recursion_remaining < -50) {
/* Overflowing while handling an overflow. Give up. */
Py_FatalError("Cannot recover from Python stack overflow.");
}
}
else {
if (tstate->py_recursion_remaining <= 0) {
tstate->recursion_headroom++;
_PyErr_Format(tstate, PyExc_RecursionError,
"maximum recursion depth exceeded");
tstate->recursion_headroom--;
return -1;
}
}
return 0;
}
static inline int _Py_EnterRecursivePy(PyThreadState *tstate) {
return (tstate->py_recursion_remaining-- <= 0) &&
_Py_CheckRecursiveCallPy(tstate);
}
static inline void _Py_LeaveRecursiveCallPy(PyThreadState *tstate) {
tstate->py_recursion_remaining++;
}
/* Disable unused label warnings. They are handy for debugging, even
if computed gotos aren't used. */
/* TBD - what about other compilers? */
#if defined(__GNUC__)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunused-label"
#elif defined(_MSC_VER) /* MS_WINDOWS */
# pragma warning(push)
# pragma warning(disable:4102)
#endif
PyObject* _Py_HOT_FUNCTION
_PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int throwflag)
{
_Py_EnsureTstateNotNULL(tstate);
CALL_STAT_INC(pyeval_calls);
#if USE_COMPUTED_GOTOS
/* Import the static jump table */
#include "opcode_targets.h"
#endif
#ifdef Py_STATS
int lastopcode = 0;
#endif
// opcode is an 8-bit value to improve the code generated by MSVC
// for the big switch below (in combination with the EXTRA_CASES macro).
uint8_t opcode; /* Current opcode */
int oparg; /* Current opcode argument, if any */
#ifdef LLTRACE
int lltrace = 0;
#endif
_PyCFrame cframe;
_PyInterpreterFrame entry_frame;
PyObject *kwnames = NULL; // Borrowed reference. Reset by CALL instructions.
/* WARNING: Because the _PyCFrame lives on the C stack,
* but can be accessed from a heap allocated object (tstate)
* strict stack discipline must be maintained.
*/
_PyCFrame *prev_cframe = tstate->cframe;
cframe.previous = prev_cframe;
tstate->cframe = &cframe;
assert(tstate->interp->interpreter_trampoline != NULL);
#ifdef Py_DEBUG
/* Set these to invalid but identifiable values for debugging. */
entry_frame.f_funcobj = (PyObject*)0xaaa0;
entry_frame.f_locals = (PyObject*)0xaaa1;
entry_frame.frame_obj = (PyFrameObject*)0xaaa2;
entry_frame.f_globals = (PyObject*)0xaaa3;
entry_frame.f_builtins = (PyObject*)0xaaa4;
#endif
entry_frame.f_code = tstate->interp->interpreter_trampoline;
entry_frame.prev_instr =
_PyCode_CODE(tstate->interp->interpreter_trampoline);
entry_frame.stacktop = 0;
entry_frame.owner = FRAME_OWNED_BY_CSTACK;
entry_frame.return_offset = 0;
/* Push frame */
entry_frame.previous = prev_cframe->current_frame;
frame->previous = &entry_frame;
cframe.current_frame = frame;
if (_Py_EnterRecursiveCallTstate(tstate, "")) {
tstate->c_recursion_remaining--;
tstate->py_recursion_remaining--;
goto exit_unwind;
}
/* support for generator.throw() */
if (throwflag) {
if (_Py_EnterRecursivePy(tstate)) {
goto exit_unwind;
}
/* Because this avoids the RESUME,
* we need to update instrumentation */
_Py_Instrument(frame->f_code, tstate->interp);
monitor_throw(tstate, frame, frame->prev_instr);
/* TO DO -- Monitor throw entry. */
goto resume_with_error;
}
/* Local "register" variables.
* These are cached values from the frame and code object. */
_Py_CODEUNIT *next_instr;
PyObject **stack_pointer;
/* Sets the above local variables from the frame */
#define SET_LOCALS_FROM_FRAME() \
assert(_PyInterpreterFrame_LASTI(frame) >= -1); \
/* Jump back to the last instruction executed... */ \
next_instr = frame->prev_instr + 1; \
stack_pointer = _PyFrame_GetStackPointer(frame);
start_frame:
if (_Py_EnterRecursivePy(tstate)) {
goto exit_unwind;
}
resume_frame:
SET_LOCALS_FROM_FRAME();
#ifdef LLTRACE
{
if (frame != &entry_frame) {
int r = PyDict_Contains(GLOBALS(), &_Py_ID(__lltrace__));
if (r < 0) {
goto exit_unwind;
}
lltrace = r;
}
if (lltrace) {
lltrace_resume_frame(frame);
}
}
#endif
#ifdef Py_DEBUG
/* _PyEval_EvalFrameDefault() must not be called with an exception set,
because it can clear it (directly or indirectly) and so the
caller loses its exception */
assert(!_PyErr_Occurred(tstate));
#endif
DISPATCH();
handle_eval_breaker:
/* Do periodic things, like check for signals and async I/0.
* We need to do reasonably frequently, but not too frequently.
* All loops should include a check of the eval breaker.
* We also check on return from any builtin function.
*
* ## More Details ###
*
* The eval loop (this function) normally executes the instructions
* of a code object sequentially. However, the runtime supports a
* number of out-of-band execution scenarios that may pause that
* sequential execution long enough to do that out-of-band work
* in the current thread using the current PyThreadState.
*
* The scenarios include:
*
* - cyclic garbage collection
* - GIL drop requests
* - "async" exceptions
* - "pending calls" (some only in the main thread)
* - signal handling (only in the main thread)
*
* When the need for one of the above is detected, the eval loop
* pauses long enough to handle the detected case. Then, if doing
* so didn't trigger an exception, the eval loop resumes executing
* the sequential instructions.
*
* To make this work, the eval loop periodically checks if any
* of the above needs to happen. The individual checks can be
* expensive if computed each time, so a while back we switched
* to using pre-computed, per-interpreter variables for the checks,
* and later consolidated that to a single "eval breaker" variable
* (now a PyInterpreterState field).
*
* For the longest time, the eval breaker check would happen
* frequently, every 5 or so times through the loop, regardless
* of what instruction ran last or what would run next. Then, in
* early 2021 (gh-18334, commit 4958f5d), we switched to checking
* the eval breaker less frequently, by hard-coding the check to
* specific places in the eval loop (e.g. certain instructions).
* The intent then was to check after returning from calls
* and on the back edges of loops.
*
* In addition to being more efficient, that approach keeps
* the eval loop from running arbitrary code between instructions
* that don't handle that well. (See gh-74174.)
*
* Currently, the eval breaker check happens here at the
* "handle_eval_breaker" label. Some instructions come here
* explicitly (goto) and some indirectly. Notably, the check
* happens on back edges in the control flow graph, which
* pretty much applies to all loops and most calls.
* (See bytecodes.c for exact information.)
*
* One consequence of this approach is that it might not be obvious
* how to force any specific thread to pick up the eval breaker,
* or for any specific thread to not pick it up. Mostly this
* involves judicious uses of locks and careful ordering of code,
* while avoiding code that might trigger the eval breaker
* until so desired.
*/
if (_Py_HandlePending(tstate) != 0) {
goto error;
}
DISPATCH();
{
/* Start instructions */
#if !USE_COMPUTED_GOTOS
dispatch_opcode:
switch (opcode)
#endif
{
#include "generated_cases.c.h"
/* INSTRUMENTED_LINE has to be here, rather than in bytecodes.c,
* because it needs to capture frame->prev_instr before it is updated,
* as happens in the standard instruction prologue.
*/
#if USE_COMPUTED_GOTOS
TARGET_INSTRUMENTED_LINE:
#else
case INSTRUMENTED_LINE:
#endif
{
_Py_CODEUNIT *prev = frame->prev_instr;
_Py_CODEUNIT *here = frame->prev_instr = next_instr;
_PyFrame_SetStackPointer(frame, stack_pointer);
int original_opcode = _Py_call_instrumentation_line(
tstate, frame, here, prev);
stack_pointer = _PyFrame_GetStackPointer(frame);
if (original_opcode < 0) {
next_instr = here+1;
goto error;
}
next_instr = frame->prev_instr;
if (next_instr != here) {
DISPATCH();
}
if (_PyOpcode_Caches[original_opcode]) {
_PyBinaryOpCache *cache = (_PyBinaryOpCache *)(next_instr+1);
/* Prevent the underlying instruction from specializing
* and overwriting the instrumentation. */
INCREMENT_ADAPTIVE_COUNTER(cache->counter);
}
opcode = original_opcode;
DISPATCH_GOTO();
}
#if USE_COMPUTED_GOTOS
_unknown_opcode:
#else
EXTRA_CASES // From opcode.h, a 'case' for each unused opcode
#endif
/* Tell C compilers not to hold the opcode variable in the loop.
next_instr points the current instruction without TARGET(). */
opcode = next_instr->op.code;
_PyErr_Format(tstate, PyExc_SystemError,
"%U:%d: unknown opcode %d",
frame->f_code->co_filename,
PyUnstable_InterpreterFrame_GetLine(frame),
opcode);
goto error;
} /* End instructions */
/* This should never be reached. Every opcode should end with DISPATCH()
or goto error. */
Py_UNREACHABLE();
unbound_local_error:
{
format_exc_check_arg(tstate, PyExc_UnboundLocalError,
UNBOUNDLOCAL_ERROR_MSG,
PyTuple_GetItem(frame->f_code->co_localsplusnames, oparg)
);
goto error;
}
pop_4_error:
STACK_SHRINK(1);
pop_3_error:
STACK_SHRINK(1);
pop_2_error:
STACK_SHRINK(1);
pop_1_error:
STACK_SHRINK(1);
error:
kwnames = NULL;
/* Double-check exception status. */
#ifdef NDEBUG
if (!_PyErr_Occurred(tstate)) {
_PyErr_SetString(tstate, PyExc_SystemError,
"error return without exception set");
}
#else
assert(_PyErr_Occurred(tstate));
#endif
/* Log traceback info. */
assert(frame != &entry_frame);
if (!_PyFrame_IsIncomplete(frame)) {
PyFrameObject *f = _PyFrame_GetFrameObject(frame);
if (f != NULL) {
PyTraceBack_Here(f);
}
}
monitor_raise(tstate, frame, next_instr-1);
exception_unwind:
{
/* We can't use frame->f_lasti here, as RERAISE may have set it */
int offset = INSTR_OFFSET()-1;
int level, handler, lasti;
if (get_exception_handler(frame->f_code, offset, &level, &handler, &lasti) == 0) {
// No handlers, so exit.
assert(_PyErr_Occurred(tstate));
/* Pop remaining stack entries. */
PyObject **stackbase = _PyFrame_Stackbase(frame);
while (stack_pointer > stackbase) {
PyObject *o = POP();
Py_XDECREF(o);
}
assert(STACK_LEVEL() == 0);
_PyFrame_SetStackPointer(frame, stack_pointer);
monitor_unwind(tstate, frame, next_instr-1);
goto exit_unwind;
}
assert(STACK_LEVEL() >= level);
PyObject **new_top = _PyFrame_Stackbase(frame) + level;
while (stack_pointer > new_top) {
PyObject *v = POP();
Py_XDECREF(v);
}
if (lasti) {
int frame_lasti = _PyInterpreterFrame_LASTI(frame);
PyObject *lasti = PyLong_FromLong(frame_lasti);
if (lasti == NULL) {
goto exception_unwind;
}
PUSH(lasti);
}
/* Make the raw exception data
available to the handler,
so a program can emulate the
Python main loop. */
PyObject *exc = _PyErr_GetRaisedException(tstate);
PUSH(exc);
JUMPTO(handler);
monitor_handled(tstate, frame, next_instr, exc);
/* Resume normal execution */
DISPATCH();
}
}
exit_unwind:
assert(_PyErr_Occurred(tstate));
_Py_LeaveRecursiveCallPy(tstate);
assert(frame != &entry_frame);
// GH-99729: We need to unlink the frame *before* clearing it:
_PyInterpreterFrame *dying = frame;
frame = cframe.current_frame = dying->previous;
_PyEvalFrameClearAndPop(tstate, dying);
frame->return_offset = 0;
if (frame == &entry_frame) {
/* Restore previous cframe and exit */
tstate->cframe = cframe.previous;
assert(tstate->cframe->current_frame == frame->previous);
_Py_LeaveRecursiveCallTstate(tstate);
return NULL;
}
resume_with_error:
SET_LOCALS_FROM_FRAME();
goto error;
}
#if defined(__GNUC__)
# pragma GCC diagnostic pop
#elif defined(_MSC_VER) /* MS_WINDOWS */