pybind11/tests/test_multiple_inheritance.py
Jason Rhinelander c4e180081d Reimplement py::init<...> to use common factory code
This reimplements the py::init<...> implementations using the various
functions added to support `py::init(...)`, and moves the implementing
structs into `detail/init.h` from `pybind11.h`.  It doesn't simply use a
factory directly, as this is a very common case and implementation
without an extra lambda call is a small but useful optimization.

This, combined with the previous lazy initialization, also avoids
needing placement new for `py::init<...>()` construction: such
construction now occurs via an ordinary `new Type(...)`.

A consequence of this is that it also fixes a potential bug when using
multiple inheritance from Python: it was very easy to write classes
that double-initialize an existing instance which had the potential to
leak for non-pod classes.  With the new implementation, an attempt to
call `__init__` on an already-initialized object is now ignored.  (This
was already done in the previous commit for factory constructors).

This change exposed a few warnings (fixed here) from deleting a pointer
to a base class with virtual functions but without a virtual destructor.
These look like legitimate warnings that we shouldn't suppress; this
adds virtual destructors to the appropriate classes.
2017-08-17 09:33:27 -04:00

350 lines
9.0 KiB
Python

import pytest
from pybind11_tests import ConstructorStats
from pybind11_tests import multiple_inheritance as m
def test_multiple_inheritance_cpp():
mt = m.MIType(3, 4)
assert mt.foo() == 3
assert mt.bar() == 4
def test_multiple_inheritance_mix1():
class Base1:
def __init__(self, i):
self.i = i
def foo(self):
return self.i
class MITypePy(Base1, m.Base2):
def __init__(self, i, j):
Base1.__init__(self, i)
m.Base2.__init__(self, j)
mt = MITypePy(3, 4)
assert mt.foo() == 3
assert mt.bar() == 4
def test_multiple_inheritance_mix2():
class Base2:
def __init__(self, i):
self.i = i
def bar(self):
return self.i
class MITypePy(m.Base1, Base2):
def __init__(self, i, j):
m.Base1.__init__(self, i)
Base2.__init__(self, j)
mt = MITypePy(3, 4)
assert mt.foo() == 3
assert mt.bar() == 4
def test_multiple_inheritance_python():
class MI1(m.Base1, m.Base2):
def __init__(self, i, j):
m.Base1.__init__(self, i)
m.Base2.__init__(self, j)
class B1(object):
def v(self):
return 1
class MI2(B1, m.Base1, m.Base2):
def __init__(self, i, j):
B1.__init__(self)
m.Base1.__init__(self, i)
m.Base2.__init__(self, j)
class MI3(MI2):
def __init__(self, i, j):
MI2.__init__(self, i, j)
class MI4(MI3, m.Base2):
def __init__(self, i, j):
MI3.__init__(self, i, j)
# This should be ignored (Base2 is already initialized via MI2):
m.Base2.__init__(self, i + 100)
class MI5(m.Base2, B1, m.Base1):
def __init__(self, i, j):
B1.__init__(self)
m.Base1.__init__(self, i)
m.Base2.__init__(self, j)
class MI6(m.Base2, B1):
def __init__(self, i):
m.Base2.__init__(self, i)
B1.__init__(self)
class B2(B1):
def v(self):
return 2
class B3(object):
def v(self):
return 3
class B4(B3, B2):
def v(self):
return 4
class MI7(B4, MI6):
def __init__(self, i):
B4.__init__(self)
MI6.__init__(self, i)
class MI8(MI6, B3):
def __init__(self, i):
MI6.__init__(self, i)
B3.__init__(self)
class MI8b(B3, MI6):
def __init__(self, i):
B3.__init__(self)
MI6.__init__(self, i)
mi1 = MI1(1, 2)
assert mi1.foo() == 1
assert mi1.bar() == 2
mi2 = MI2(3, 4)
assert mi2.v() == 1
assert mi2.foo() == 3
assert mi2.bar() == 4
mi3 = MI3(5, 6)
assert mi3.v() == 1
assert mi3.foo() == 5
assert mi3.bar() == 6
mi4 = MI4(7, 8)
assert mi4.v() == 1
assert mi4.foo() == 7
assert mi4.bar() == 8
mi5 = MI5(10, 11)
assert mi5.v() == 1
assert mi5.foo() == 10
assert mi5.bar() == 11
mi6 = MI6(12)
assert mi6.v() == 1
assert mi6.bar() == 12
mi7 = MI7(13)
assert mi7.v() == 4
assert mi7.bar() == 13
mi8 = MI8(14)
assert mi8.v() == 1
assert mi8.bar() == 14
mi8b = MI8b(15)
assert mi8b.v() == 3
assert mi8b.bar() == 15
def test_multiple_inheritance_python_many_bases():
class MIMany14(m.BaseN1, m.BaseN2, m.BaseN3, m.BaseN4):
def __init__(self):
m.BaseN1.__init__(self, 1)
m.BaseN2.__init__(self, 2)
m.BaseN3.__init__(self, 3)
m.BaseN4.__init__(self, 4)
class MIMany58(m.BaseN5, m.BaseN6, m.BaseN7, m.BaseN8):
def __init__(self):
m.BaseN5.__init__(self, 5)
m.BaseN6.__init__(self, 6)
m.BaseN7.__init__(self, 7)
m.BaseN8.__init__(self, 8)
class MIMany916(m.BaseN9, m.BaseN10, m.BaseN11, m.BaseN12, m.BaseN13, m.BaseN14, m.BaseN15,
m.BaseN16):
def __init__(self):
m.BaseN9.__init__(self, 9)
m.BaseN10.__init__(self, 10)
m.BaseN11.__init__(self, 11)
m.BaseN12.__init__(self, 12)
m.BaseN13.__init__(self, 13)
m.BaseN14.__init__(self, 14)
m.BaseN15.__init__(self, 15)
m.BaseN16.__init__(self, 16)
class MIMany19(MIMany14, MIMany58, m.BaseN9):
def __init__(self):
MIMany14.__init__(self)
MIMany58.__init__(self)
m.BaseN9.__init__(self, 9)
class MIMany117(MIMany14, MIMany58, MIMany916, m.BaseN17):
def __init__(self):
MIMany14.__init__(self)
MIMany58.__init__(self)
MIMany916.__init__(self)
m.BaseN17.__init__(self, 17)
# Inherits from 4 registered C++ classes: can fit in one pointer on any modern arch:
a = MIMany14()
for i in range(1, 4):
assert getattr(a, "f" + str(i))() == 2 * i
# Inherits from 8: requires 1/2 pointers worth of holder flags on 32/64-bit arch:
b = MIMany916()
for i in range(9, 16):
assert getattr(b, "f" + str(i))() == 2 * i
# Inherits from 9: requires >= 2 pointers worth of holder flags
c = MIMany19()
for i in range(1, 9):
assert getattr(c, "f" + str(i))() == 2 * i
# Inherits from 17: requires >= 3 pointers worth of holder flags
d = MIMany117()
for i in range(1, 17):
assert getattr(d, "f" + str(i))() == 2 * i
def test_multiple_inheritance_virtbase():
class MITypePy(m.Base12a):
def __init__(self, i, j):
m.Base12a.__init__(self, i, j)
mt = MITypePy(3, 4)
assert mt.bar() == 4
assert m.bar_base2a(mt) == 4
assert m.bar_base2a_sharedptr(mt) == 4
def test_mi_static_properties():
"""Mixing bases with and without static properties should be possible
and the result should be independent of base definition order"""
for d in (m.VanillaStaticMix1(), m.VanillaStaticMix2()):
assert d.vanilla() == "Vanilla"
assert d.static_func1() == "WithStatic1"
assert d.static_func2() == "WithStatic2"
assert d.static_func() == d.__class__.__name__
m.WithStatic1.static_value1 = 1
m.WithStatic2.static_value2 = 2
assert d.static_value1 == 1
assert d.static_value2 == 2
assert d.static_value == 12
d.static_value1 = 0
assert d.static_value1 == 0
d.static_value2 = 0
assert d.static_value2 == 0
d.static_value = 0
assert d.static_value == 0
@pytest.unsupported_on_pypy
def test_mi_dynamic_attributes():
"""Mixing bases with and without dynamic attribute support"""
for d in (m.VanillaDictMix1(), m.VanillaDictMix2()):
d.dynamic = 1
assert d.dynamic == 1
def test_mi_unaligned_base():
"""Returning an offset (non-first MI) base class pointer should recognize the instance"""
n_inst = ConstructorStats.detail_reg_inst()
c = m.I801C()
d = m.I801D()
# + 4 below because we have the two instances, and each instance has offset base I801B2
assert ConstructorStats.detail_reg_inst() == n_inst + 4
b1c = m.i801b1_c(c)
assert b1c is c
b2c = m.i801b2_c(c)
assert b2c is c
b1d = m.i801b1_d(d)
assert b1d is d
b2d = m.i801b2_d(d)
assert b2d is d
assert ConstructorStats.detail_reg_inst() == n_inst + 4 # no extra instances
del c, b1c, b2c
assert ConstructorStats.detail_reg_inst() == n_inst + 2
del d, b1d, b2d
assert ConstructorStats.detail_reg_inst() == n_inst
def test_mi_base_return():
"""Tests returning an offset (non-first MI) base class pointer to a derived instance"""
n_inst = ConstructorStats.detail_reg_inst()
c1 = m.i801c_b1()
assert type(c1) is m.I801C
assert c1.a == 1
assert c1.b == 2
d1 = m.i801d_b1()
assert type(d1) is m.I801D
assert d1.a == 1
assert d1.b == 2
assert ConstructorStats.detail_reg_inst() == n_inst + 4
c2 = m.i801c_b2()
assert type(c2) is m.I801C
assert c2.a == 1
assert c2.b == 2
d2 = m.i801d_b2()
assert type(d2) is m.I801D
assert d2.a == 1
assert d2.b == 2
assert ConstructorStats.detail_reg_inst() == n_inst + 8
del c2
assert ConstructorStats.detail_reg_inst() == n_inst + 6
del c1, d1, d2
assert ConstructorStats.detail_reg_inst() == n_inst
# Returning an unregistered derived type with a registered base; we won't
# pick up the derived type, obviously, but should still work (as an object
# of whatever type was returned).
e1 = m.i801e_c()
assert type(e1) is m.I801C
assert e1.a == 1
assert e1.b == 2
e2 = m.i801e_b2()
assert type(e2) is m.I801B2
assert e2.b == 2
def test_diamond_inheritance():
"""Tests that diamond inheritance works as expected (issue #959)"""
# Issue #959: this shouldn't segfault:
d = m.D()
# Make sure all the various distinct pointers are all recognized as registered instances:
assert d is d.c0()
assert d is d.c1()
assert d is d.b()
assert d is d.c0().b()
assert d is d.c1().b()
assert d is d.c0().c1().b().c0().b()