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# The compact 4-character naming scheme (e.g. mptr, cptr, shcp) is explained at the top of
# test_class_sh_property.cpp.
from __future__ import annotations
import pytest
import env # noqa: F401
from pybind11_tests import class_sh_property as m
@pytest.mark.skipif(
"env.PYPY or env.GRAALPY", reason="gc after `del field` is apparently deferred"
)
@pytest.mark.parametrize("m_attr", ["m_valu_readonly", "m_valu_readwrite"])
def test_valu_getter(m_attr):
# Reduced from PyCLIF test:
# https://github.com/google/clif/blob/c371a6d4b28d25d53a16e6d2a6d97305fb1be25a/clif/testing/python/nested_fields_test.py#L56
outer = m.Outer()
field = getattr(outer, m_attr)
assert field.num == -99
with pytest.raises(ValueError) as excinfo:
m.DisownOuter(outer)
assert str(excinfo.value) == "Cannot disown use_count != 1 (load_as_unique_ptr)."
del field
m.DisownOuter(outer)
with pytest.raises(ValueError, match="Python instance was disowned") as excinfo:
getattr(outer, m_attr)
def test_valu_setter():
outer = m.Outer()
assert outer.m_valu_readonly.num == -99
assert outer.m_valu_readwrite.num == -99
field = m.Field()
field.num = 35
outer.m_valu_readwrite = field
assert outer.m_valu_readonly.num == 35
assert outer.m_valu_readwrite.num == 35
@pytest.mark.parametrize("m_attr", ["m_shmp", "m_shcp"])
def test_shp(m_attr):
m_attr_readonly = m_attr + "_readonly"
m_attr_readwrite = m_attr + "_readwrite"
outer = m.Outer()
assert getattr(outer, m_attr_readonly) is None
assert getattr(outer, m_attr_readwrite) is None
field = m.Field()
field.num = 43
setattr(outer, m_attr_readwrite, field)
assert getattr(outer, m_attr_readonly).num == 43
assert getattr(outer, m_attr_readwrite).num == 43
getattr(outer, m_attr_readonly).num = 57
getattr(outer, m_attr_readwrite).num = 57
assert field.num == 57
del field
assert getattr(outer, m_attr_readonly).num == 57
assert getattr(outer, m_attr_readwrite).num == 57
@pytest.mark.parametrize(
("field_type", "num_default", "outer_type"),
[
(m.ClassicField, -88, m.ClassicOuter),
(m.Field, -99, m.Outer),
],
)
@pytest.mark.parametrize("m_attr", ["m_mptr", "m_cptr"])
@pytest.mark.parametrize("r_kind", ["_readonly", "_readwrite"])
def test_ptr(field_type, num_default, outer_type, m_attr, r_kind):
m_attr_r_kind = m_attr + r_kind
outer = outer_type()
assert getattr(outer, m_attr_r_kind) is None
field = field_type()
assert field.num == num_default
setattr(outer, m_attr + "_readwrite", field)
assert getattr(outer, m_attr_r_kind).num == num_default
field.num = 76
assert getattr(outer, m_attr_r_kind).num == 76
# Change to -88 or -99 to demonstrate Undefined Behavior (dangling pointer).
if num_default == 88 and m_attr == "m_mptr":
del field
assert getattr(outer, m_attr_r_kind).num == 76
@pytest.mark.parametrize("m_attr_readwrite", ["m_uqmp_readwrite", "m_uqcp_readwrite"])
def test_uqp(m_attr_readwrite):
outer = m.Outer()
assert getattr(outer, m_attr_readwrite) is None
field_orig = m.Field()
field_orig.num = 39
setattr(outer, m_attr_readwrite, field_orig)
with pytest.raises(ValueError, match="Python instance was disowned"):
_ = field_orig.num
field_retr1 = getattr(outer, m_attr_readwrite)
assert getattr(outer, m_attr_readwrite) is None
assert field_retr1.num == 39
field_retr1.num = 93
setattr(outer, m_attr_readwrite, field_retr1)
with pytest.raises(ValueError):
_ = field_retr1.num
field_retr2 = getattr(outer, m_attr_readwrite)
assert field_retr2.num == 93
# Proof-of-concept (POC) for safe & intuitive Python access to unique_ptr members.
# The C++ member unique_ptr is disowned to a temporary Python object for accessing
# an attribute of the member. After the attribute was accessed, the Python object
# is disowned back to the C++ member unique_ptr.
# Productizing this POC is left for a future separate PR, as needed.
class unique_ptr_field_proxy_poc:
def __init__(self, obj, field_name):
object.__setattr__(self, "__obj", obj)
object.__setattr__(self, "__field_name", field_name)
def __getattr__(self, *args, **kwargs):
return _proxy_dereference(self, getattr, *args, **kwargs)
def __setattr__(self, *args, **kwargs):
return _proxy_dereference(self, setattr, *args, **kwargs)
def __delattr__(self, *args, **kwargs):
return _proxy_dereference(self, delattr, *args, **kwargs)
def _proxy_dereference(proxy, xxxattr, *args, **kwargs):
obj = object.__getattribute__(proxy, "__obj")
field_name = object.__getattribute__(proxy, "__field_name")
field = getattr(obj, field_name) # Disowns the C++ unique_ptr member.
assert field is not None
try:
return xxxattr(field, *args, **kwargs)
finally:
setattr(obj, field_name, field) # Disowns the temporary Python object (field).
@pytest.mark.parametrize("m_attr", ["m_uqmp", "m_uqcp"])
def test_unique_ptr_field_proxy_poc(m_attr):
m_attr_readwrite = m_attr + "_readwrite"
outer = m.Outer()
field_orig = m.Field()
field_orig.num = 45
setattr(outer, m_attr_readwrite, field_orig)
field_proxy = unique_ptr_field_proxy_poc(outer, m_attr_readwrite)
assert field_proxy.num == 45
assert field_proxy.num == 45
with pytest.raises(AttributeError):
_ = field_proxy.xyz
assert field_proxy.num == 45
field_proxy.num = 82
assert field_proxy.num == 82
field_proxy = unique_ptr_field_proxy_poc(outer, m_attr_readwrite)
assert field_proxy.num == 82
with pytest.raises(AttributeError):
del field_proxy.num
assert field_proxy.num == 82
def test_readonly_char6_member():
obj = m.WithCharArrayMember()
assert obj.char6_member == "Char6"
def test_readonly_const_char_ptr_member():
obj = m.WithConstCharPtrMember()
assert obj.const_char_ptr_member == "ConstChar*"
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