1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
#define _PY_INTERPRETER
#include "Python.h"
#include "pycore_frame.h" // _PyFrame_New_NoTrack()
#include "pycore_interpframe.h" // _PyFrame_GetCode()
#include "pycore_genobject.h" // _PyGen_GetGeneratorFromFrame()
#include "pycore_stackref.h" // _Py_VISIT_STACKREF()
int
_PyFrame_Traverse(_PyInterpreterFrame *frame, visitproc visit, void *arg)
{
Py_VISIT(frame->frame_obj);
Py_VISIT(frame->f_locals);
_Py_VISIT_STACKREF(frame->f_funcobj);
_Py_VISIT_STACKREF(frame->f_executable);
return _PyGC_VisitFrameStack(frame, visit, arg);
}
PyFrameObject *
_PyFrame_MakeAndSetFrameObject(_PyInterpreterFrame *frame)
{
assert(frame->frame_obj == NULL);
PyObject *exc = PyErr_GetRaisedException();
PyFrameObject *f = _PyFrame_New_NoTrack(_PyFrame_GetCode(frame));
if (f == NULL) {
Py_XDECREF(exc);
return NULL;
}
PyErr_SetRaisedException(exc);
// GH-97002: There was a time when a frame object could be created when we
// are allocating the new frame object f above, so frame->frame_obj would
// be assigned already. That path does not exist anymore. We won't call any
// Python code in this function and garbage collection will not run.
// Notice that _PyFrame_New_NoTrack() can potentially raise a MemoryError,
// but it won't allocate a traceback until the frame unwinds, so we are safe
// here.
assert(frame->frame_obj == NULL);
assert(frame->owner != FRAME_OWNED_BY_FRAME_OBJECT);
f->f_frame = frame;
frame->frame_obj = f;
return f;
}
static void
take_ownership(PyFrameObject *f, _PyInterpreterFrame *frame)
{
Py_BEGIN_CRITICAL_SECTION(f);
assert(frame->owner < FRAME_OWNED_BY_INTERPRETER);
assert(frame->owner != FRAME_OWNED_BY_FRAME_OBJECT);
_PyInterpreterFrame *new_frame = (_PyInterpreterFrame *)f->_f_frame_data;
_PyFrame_Copy(frame, new_frame);
// _PyFrame_Copy takes the reference to the executable,
// so we need to restore it.
frame->f_executable = PyStackRef_DUP(new_frame->f_executable);
f->f_frame = new_frame;
new_frame->owner = FRAME_OWNED_BY_FRAME_OBJECT;
if (_PyFrame_IsIncomplete(new_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 = _PyFrame_GetCode(new_frame);
new_frame->instr_ptr =
_PyFrame_GetBytecode(new_frame) + code->_co_firsttraceable + 1;
}
assert(!_PyFrame_IsIncomplete(new_frame));
assert(f->f_back == NULL);
_PyInterpreterFrame *prev = _PyFrame_GetFirstComplete(frame->previous);
if (prev) {
assert(prev->owner < FRAME_OWNED_BY_INTERPRETER);
PyObject *exc = PyErr_GetRaisedException();
/* Link PyFrameObjects.f_back and remove link through _PyInterpreterFrame.previous */
PyFrameObject *back = _PyFrame_GetFrameObject(prev);
if (back == NULL) {
/* Memory error here. */
assert(PyErr_ExceptionMatches(PyExc_MemoryError));
/* Nothing we can do about it */
PyErr_Clear();
}
else {
f->f_back = (PyFrameObject *)Py_NewRef(back);
}
PyErr_SetRaisedException(exc);
}
if (!_PyObject_GC_IS_TRACKED((PyObject *)f)) {
_PyObject_GC_TRACK((PyObject *)f);
}
Py_END_CRITICAL_SECTION();
}
void
_PyFrame_ClearLocals(_PyInterpreterFrame *frame)
{
assert(frame->stackpointer != NULL);
_PyStackRef *sp = frame->stackpointer;
_PyStackRef *locals = frame->localsplus;
frame->stackpointer = locals;
while (sp > locals) {
sp--;
PyStackRef_XCLOSE(*sp);
}
Py_CLEAR(frame->f_locals);
}
void
_PyFrame_ClearExceptCode(_PyInterpreterFrame *frame)
{
/* It is the responsibility of the owning generator/coroutine
* to have cleared the enclosing generator, if any. */
assert(frame->owner != FRAME_OWNED_BY_GENERATOR ||
_PyGen_GetGeneratorFromFrame(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:
assert(_PyThreadState_GET()->current_frame != frame);
if (frame->frame_obj) {
PyFrameObject *f = frame->frame_obj;
frame->frame_obj = NULL;
if (!_PyObject_IsUniquelyReferenced((PyObject *)f)) {
take_ownership(f, frame);
Py_DECREF(f);
return;
}
Py_DECREF(f);
}
_PyFrame_ClearLocals(frame);
PyStackRef_CLEAR(frame->f_funcobj);
}
/* Unstable API functions */
PyObject *
PyUnstable_InterpreterFrame_GetCode(struct _PyInterpreterFrame *frame)
{
return PyStackRef_AsPyObjectNew(frame->f_executable);
}
int
PyUnstable_InterpreterFrame_GetLasti(struct _PyInterpreterFrame *frame)
{
return _PyInterpreterFrame_LASTI(frame) * sizeof(_Py_CODEUNIT);
}
// NOTE: We allow racy accesses to the instruction pointer from other threads
// for sys._current_frames() and similar APIs.
int _Py_NO_SANITIZE_THREAD
PyUnstable_InterpreterFrame_GetLine(_PyInterpreterFrame *frame)
{
int addr = _PyInterpreterFrame_LASTI(frame) * sizeof(_Py_CODEUNIT);
return PyCode_Addr2Line(_PyFrame_GetCode(frame), addr);
}
const PyTypeObject *const PyUnstable_ExecutableKinds[PyUnstable_EXECUTABLE_KINDS+1] = {
[PyUnstable_EXECUTABLE_KIND_SKIP] = &_PyNone_Type,
[PyUnstable_EXECUTABLE_KIND_PY_FUNCTION] = &PyCode_Type,
[PyUnstable_EXECUTABLE_KIND_BUILTIN_FUNCTION] = &PyMethod_Type,
[PyUnstable_EXECUTABLE_KIND_METHOD_DESCRIPTOR] = &PyMethodDescr_Type,
[PyUnstable_EXECUTABLE_KINDS] = NULL,
};
|
