[Python-checkins] GH-97779: Ensure that *all* frame objects are backed by "complete" frames (GH-97845)
brandtbucher
webhook-mailer at python.org
Tue Oct 4 20:30:12 EDT 2022
https://github.com/python/cpython/commit/0ff8fd65838f9f9ed90d7a055d26a2ce9fc0ce85
commit: 0ff8fd65838f9f9ed90d7a055d26a2ce9fc0ce85
branch: main
author: Brandt Bucher <brandtbucher at microsoft.com>
committer: brandtbucher <brandtbucher at gmail.com>
date: 2022-10-04T17:30:03-07:00
summary:
GH-97779: Ensure that *all* frame objects are backed by "complete" frames (GH-97845)
files:
A Misc/NEWS.d/next/Core and Builtins/2022-10-04-02-00-10.gh-issue-97779.f3N1hI.rst
M Lib/test/test_code.py
M Objects/codeobject.c
M Objects/frameobject.c
M Python/frame.c
diff --git a/Lib/test/test_code.py b/Lib/test/test_code.py
index 2fdfdd0d309c..4e4d82314a9f 100644
--- a/Lib/test/test_code.py
+++ b/Lib/test/test_code.py
@@ -132,6 +132,7 @@
import unittest
import textwrap
import weakref
+import dis
try:
import ctypes
@@ -682,6 +683,38 @@ def test_lines(self):
self.check_lines(misshappen)
self.check_lines(bug93662)
+ @cpython_only
+ def test_code_new_empty(self):
+ # If this test fails, it means that the construction of PyCode_NewEmpty
+ # needs to be modified! Please update this test *and* PyCode_NewEmpty,
+ # so that they both stay in sync.
+ def f():
+ pass
+ PY_CODE_LOCATION_INFO_NO_COLUMNS = 13
+ f.__code__ = f.__code__.replace(
+ co_firstlineno=42,
+ co_code=bytes(
+ [
+ dis.opmap["RESUME"], 0,
+ dis.opmap["LOAD_ASSERTION_ERROR"], 0,
+ dis.opmap["RAISE_VARARGS"], 1,
+ ]
+ ),
+ co_linetable=bytes(
+ [
+ (1 << 7)
+ | (PY_CODE_LOCATION_INFO_NO_COLUMNS << 3)
+ | (3 - 1),
+ 0,
+ ]
+ ),
+ )
+ self.assertRaises(AssertionError, f)
+ self.assertEqual(
+ list(f.__code__.co_positions()),
+ 3 * [(42, 42, None, None)],
+ )
+
if check_impl_detail(cpython=True) and ctypes is not None:
py = ctypes.pythonapi
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-10-04-02-00-10.gh-issue-97779.f3N1hI.rst b/Misc/NEWS.d/next/Core and Builtins/2022-10-04-02-00-10.gh-issue-97779.f3N1hI.rst
new file mode 100644
index 000000000000..611521808865
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-10-04-02-00-10.gh-issue-97779.f3N1hI.rst
@@ -0,0 +1 @@
+Ensure that all Python frame objects are backed by "complete" frames.
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 7d0d038f489a..14d1d00684ae 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -638,12 +638,22 @@ PyCode_New(int argcount, int kwonlyargcount,
exceptiontable);
}
-static const char assert0[6] = {
+// NOTE: When modifying the construction of PyCode_NewEmpty, please also change
+// test.test_code.CodeLocationTest.test_code_new_empty to keep it in sync!
+
+static const uint8_t assert0[6] = {
RESUME, 0,
LOAD_ASSERTION_ERROR, 0,
RAISE_VARARGS, 1
};
+static const uint8_t linetable[2] = {
+ (1 << 7) // New entry.
+ | (PY_CODE_LOCATION_INFO_NO_COLUMNS << 3)
+ | (3 - 1), // Three code units.
+ 0, // Offset from co_firstlineno.
+};
+
PyCodeObject *
PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
{
@@ -651,6 +661,7 @@ PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
PyObject *filename_ob = NULL;
PyObject *funcname_ob = NULL;
PyObject *code_ob = NULL;
+ PyObject *linetable_ob = NULL;
PyCodeObject *result = NULL;
nulltuple = PyTuple_New(0);
@@ -665,10 +676,14 @@ PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
if (filename_ob == NULL) {
goto failed;
}
- code_ob = PyBytes_FromStringAndSize(assert0, 6);
+ code_ob = PyBytes_FromStringAndSize((const char *)assert0, 6);
if (code_ob == NULL) {
goto failed;
}
+ linetable_ob = PyBytes_FromStringAndSize((const char *)linetable, 2);
+ if (linetable_ob == NULL) {
+ goto failed;
+ }
#define emptystring (PyObject *)&_Py_SINGLETON(bytes_empty)
struct _PyCodeConstructor con = {
@@ -677,7 +692,7 @@ PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
.qualname = funcname_ob,
.code = code_ob,
.firstlineno = firstlineno,
- .linetable = emptystring,
+ .linetable = linetable_ob,
.consts = nulltuple,
.names = nulltuple,
.localsplusnames = nulltuple,
@@ -692,6 +707,7 @@ PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
Py_XDECREF(funcname_ob);
Py_XDECREF(filename_ob);
Py_XDECREF(code_ob);
+ Py_XDECREF(linetable_ob);
return result;
}
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 2e3777943126..6a51a946ef35 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -588,6 +588,7 @@ first_line_not_before(int *lines, int len, int line)
static PyFrameState
_PyFrame_GetState(PyFrameObject *frame)
{
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
if (frame->f_frame->stacktop == 0) {
return FRAME_CLEARED;
}
@@ -1094,6 +1095,9 @@ PyFrame_New(PyThreadState *tstate, PyCodeObject *code,
init_frame((_PyInterpreterFrame *)f->_f_frame_data, func, locals);
f->f_frame = (_PyInterpreterFrame *)f->_f_frame_data;
f->f_frame->owner = FRAME_OWNED_BY_FRAME_OBJECT;
+ // This frame needs to be "complete", so pretend that the first RESUME ran:
+ f->f_frame->prev_instr = _PyCode_CODE(code) + code->_co_firsttraceable;
+ assert(!_PyFrame_IsIncomplete(f->f_frame));
Py_DECREF(func);
_PyObject_GC_TRACK(f);
return f;
@@ -1222,6 +1226,7 @@ _PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame) {
int
PyFrame_FastToLocalsWithError(PyFrameObject *f)
{
+ assert(!_PyFrame_IsIncomplete(f->f_frame));
if (f == NULL) {
PyErr_BadInternalCall();
return -1;
@@ -1237,7 +1242,7 @@ void
PyFrame_FastToLocals(PyFrameObject *f)
{
int res;
-
+ assert(!_PyFrame_IsIncomplete(f->f_frame));
assert(!PyErr_Occurred());
res = PyFrame_FastToLocalsWithError(f);
@@ -1320,6 +1325,7 @@ _PyFrame_LocalsToFast(_PyInterpreterFrame *frame, int clear)
void
PyFrame_LocalsToFast(PyFrameObject *f, int clear)
{
+ assert(!_PyFrame_IsIncomplete(f->f_frame));
if (f && f->f_fast_as_locals && _PyFrame_GetState(f) != FRAME_CLEARED) {
_PyFrame_LocalsToFast(f->f_frame, clear);
f->f_fast_as_locals = 0;
@@ -1330,6 +1336,7 @@ PyFrame_LocalsToFast(PyFrameObject *f, int clear)
int _PyFrame_IsEntryFrame(PyFrameObject *frame)
{
assert(frame != NULL);
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
return frame->f_frame->is_entry;
}
@@ -1338,6 +1345,7 @@ PyCodeObject *
PyFrame_GetCode(PyFrameObject *frame)
{
assert(frame != NULL);
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
PyCodeObject *code = frame->f_frame->f_code;
assert(code != NULL);
Py_INCREF(code);
@@ -1349,6 +1357,7 @@ PyFrameObject*
PyFrame_GetBack(PyFrameObject *frame)
{
assert(frame != NULL);
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
PyFrameObject *back = frame->f_back;
if (back == NULL) {
_PyInterpreterFrame *prev = frame->f_frame->previous;
@@ -1366,24 +1375,28 @@ PyFrame_GetBack(PyFrameObject *frame)
PyObject*
PyFrame_GetLocals(PyFrameObject *frame)
{
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
return frame_getlocals(frame, NULL);
}
PyObject*
PyFrame_GetGlobals(PyFrameObject *frame)
{
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
return frame_getglobals(frame, NULL);
}
PyObject*
PyFrame_GetBuiltins(PyFrameObject *frame)
{
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
return frame_getbuiltins(frame, NULL);
}
int
PyFrame_GetLasti(PyFrameObject *frame)
{
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
int lasti = _PyInterpreterFrame_LASTI(frame->f_frame);
if (lasti < 0) {
return -1;
@@ -1394,6 +1407,7 @@ PyFrame_GetLasti(PyFrameObject *frame)
PyObject *
PyFrame_GetGenerator(PyFrameObject *frame)
{
+ assert(!_PyFrame_IsIncomplete(frame->f_frame));
if (frame->f_frame->owner != FRAME_OWNED_BY_GENERATOR) {
return NULL;
}
diff --git a/Python/frame.c b/Python/frame.c
index 05a8cffcb8a7..96566de63a78 100644
--- a/Python/frame.c
+++ b/Python/frame.c
@@ -70,6 +70,13 @@ take_ownership(PyFrameObject *f, _PyInterpreterFrame *frame)
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;
+ }
+ assert(!_PyFrame_IsIncomplete(frame));
assert(f->f_back == NULL);
_PyInterpreterFrame *prev = frame->previous;
while (prev && _PyFrame_IsIncomplete(prev)) {
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