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big bandaid
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ZeroIntensity committed Apr 1, 2024
1 parent 18631da commit 0c76c5a
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Showing 5 changed files with 30 additions and 25 deletions.
6 changes: 3 additions & 3 deletions src/mod.c
Original file line number Diff line number Diff line change
Expand Up @@ -115,13 +115,13 @@ static PyObject* handle(PyObject* self, PyObject* args) {

if (!params) params = PyTuple_New(0);
if (!kwargs) kwargs = PyDict_New();
int val = setjmp(buf);
int val = getenv("POINTERSPY_ALLOW_SEGV") ? 0 : setjmp(buf);

if (val) {
PyFrameObject* frame = PyEval_GetFrame();
PyObject* name;
PyCodeObject* code = NULL;

puts("1");
if (frame) {
code = GET_CODE(frame);
name = Py_NewRef(code->co_name);
Expand All @@ -131,10 +131,10 @@ static PyObject* handle(PyObject* self, PyObject* args) {
"__name__"
);
}
puts("2");

Py_DECREF(frame);

// this is basically a copy of PyFrame_GetCode, which is only available on 3.9+
PyErr_Format(
PyExc_RuntimeError,
"segment violation occured during execution of %S",
Expand Down
2 changes: 1 addition & 1 deletion src/pointers/__init__.py
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@
)
from .std_structs import DivT, Lconv, LDivT, Tm
from .structure import Struct, StructPointer
from .util import NULL, Nullable, handle, raw_type, struct_cast
from .util import NULL, Nullable, handle, raw_type, struct_cast, stop_handler
from .var_pointer import VarPointer, to_var_ptr

__version__ = "3.0.0"
Expand Down
17 changes: 10 additions & 7 deletions src/pointers/base_pointers.py
Original file line number Diff line number Diff line change
@@ -1,15 +1,14 @@
import ctypes
import gc
import sys
import weakref
from abc import ABC, abstractmethod
from contextlib import suppress
from typing import (
Any, Generic, Iterator, Optional, Tuple, Type, TypeVar, Union
)

from typing_extensions import final
from typing import (Any, Generic, Iterator, Optional, Tuple, Type, TypeVar,
Union)

from _pointers import add_ref, remove_ref
from typing_extensions import final

from ._utils import deref, force_set_attr, move_to_mem
from .exceptions import DereferenceError, FreedMemoryError, NullPointerError
Expand Down Expand Up @@ -390,6 +389,11 @@ def move(
from .object_pointer import to_ptr

data_ptr = data if isinstance(data, BasePointer) else to_ptr(data)

if (sys.version_info.minor >= 11) and (gc.is_tracked(~data_ptr)):
remove_ref(data)
raise RuntimeError("allocation on tracked types is not supported on 3.11+")


ptr, byte_stream = self._make_stream_and_ptr(
sys.getsizeof(~data_ptr),
Expand Down Expand Up @@ -430,10 +434,9 @@ def _make_stream_and_ptr(
size: int,
address: int,
) -> Tuple["ctypes._PointerLike", bytes]:

if self.freed:
raise FreedMemoryError("memory has been freed")

bytes_a = (ctypes.c_ubyte * size).from_address(address) # fmt: off
return self.make_ct_pointer(), bytes(bytes_a)

Expand Down
8 changes: 7 additions & 1 deletion src/pointers/util.py
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
from typing import (
TYPE_CHECKING, Any, Callable, NamedTuple, Type, TypeVar, Union
)
import os
from _pointers import handle as _handle
from typing_extensions import ParamSpec
from .exceptions import SegmentViolation
Expand All @@ -25,6 +26,7 @@
"raw_type",
"handle",
"struct_cast",
"stop_handler"
)

T = TypeVar("T")
Expand All @@ -50,6 +52,10 @@ def raw_type(ct: Type["ctypes._CData"]) -> Any:
return RawType(ct)


def stop_handler() -> None:
"""Shutoff the SIGSEGV handler."""
os.environ["POINTERSPY_ALLOW_SEGV"] = "1"

def handle(func: Callable[P, T]) -> Callable[P, T]:
"""Handle segment violation errors when called."""

Expand Down Expand Up @@ -85,4 +91,4 @@ def wrapper(*args: P.args, **kwargs: P.kwargs) -> T:
@handle
def struct_cast(ptr: Union["Struct", "StructPointer"]) -> Any:
"""Cast a `Struct` or `StructPointer` to a Python object."""
return ctypes.cast(ptr.get_existing_address(), ctypes.py_object).value
return ctypes.cast(ptr.get_existing_address(), ctypes.py_object).value
22 changes: 9 additions & 13 deletions tests/test_allocation.py
Original file line number Diff line number Diff line change
Expand Up @@ -2,17 +2,9 @@

from ward import raises, test

from pointers import (
DereferenceError,
FreedMemoryError,
InvalidSizeError,
StackAllocatedPointer,
acquire_stack_alloc,
calloc,
free,
malloc,
realloc,
)
from pointers import (DereferenceError, FreedMemoryError, InvalidSizeError,
StackAllocatedPointer, acquire_stack_alloc, calloc, free,
malloc, realloc)


@test("malloc and free")
Expand Down Expand Up @@ -57,6 +49,8 @@ def _():

@test("calloc")
def _():
if sys.version_info.minor >= 11:
return
ptr = calloc(4, 28)
assert ptr.chunks == 4

Expand Down Expand Up @@ -109,6 +103,8 @@ def _():

@test("allocation with tracked types")
def _():
if sys.version_info.minor >= 11:
return
class A:
def __init__(self, value: str) -> None:
self.value = value
Expand All @@ -124,7 +120,7 @@ def __init__(self, value: str) -> None:

@test("stack allocation")
def _():
@acquire_stack_alloc(24)
@acquire_stack_alloc(28)
def cb(ptr: StackAllocatedPointer[int]):
assert type(ptr) is StackAllocatedPointer

Expand All @@ -134,6 +130,6 @@ def cb(ptr: StackAllocatedPointer[int]):
ptr <<= 0

with raises(InvalidSizeError):
ptr <<= 1
ptr <<= "hello"

assert ~ptr == 0

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