ext/pybind11/tests/test_virtual_functions.py - public/gem5 - Git at Google

 import pytest

 from pybind11_tests import virtual_functions as m
 from pybind11_tests import ConstructorStats


 def test_override(capture, msg):
     class ExtendedExampleVirt(m.ExampleVirt):
         def __init__(self, state):
             super(ExtendedExampleVirt, self).__init__(state + 1)
             self.data = "Hello world"

         def run(self, value):
             print('ExtendedExampleVirt::run(%i), calling parent..' % value)
             return super(ExtendedExampleVirt, self).run(value + 1)

         def run_bool(self):
             print('ExtendedExampleVirt::run_bool()')
             return False

         def get_string1(self):
             return "override1"

         def pure_virtual(self):
             print('ExtendedExampleVirt::pure_virtual(): %s' % self.data)

     class ExtendedExampleVirt2(ExtendedExampleVirt):
         def __init__(self, state):
             super(ExtendedExampleVirt2, self).__init__(state + 1)

         def get_string2(self):
             return "override2"

     ex12 = m.ExampleVirt(10)
     with capture:
         assert m.runExampleVirt(ex12, 20) == 30
     assert capture == """
         Original implementation of ExampleVirt::run(state=10, value=20, str1=default1, str2=default2)
     """  # noqa: E501 line too long

     with pytest.raises(RuntimeError) as excinfo:
         m.runExampleVirtVirtual(ex12)
     assert msg(excinfo.value) == 'Tried to call pure virtual function "ExampleVirt::pure_virtual"'

     ex12p = ExtendedExampleVirt(10)
     with capture:
         assert m.runExampleVirt(ex12p, 20) == 32
     assert capture == """
         ExtendedExampleVirt::run(20), calling parent..
         Original implementation of ExampleVirt::run(state=11, value=21, str1=override1, str2=default2)
     """  # noqa: E501 line too long
     with capture:
         assert m.runExampleVirtBool(ex12p) is False
     assert capture == "ExtendedExampleVirt::run_bool()"
     with capture:
         m.runExampleVirtVirtual(ex12p)
     assert capture == "ExtendedExampleVirt::pure_virtual(): Hello world"

     ex12p2 = ExtendedExampleVirt2(15)
     with capture:
         assert m.runExampleVirt(ex12p2, 50) == 68
     assert capture == """
         ExtendedExampleVirt::run(50), calling parent..
         Original implementation of ExampleVirt::run(state=17, value=51, str1=override1, str2=override2)
     """  # noqa: E501 line too long

     cstats = ConstructorStats.get(m.ExampleVirt)
     assert cstats.alive() == 3
     del ex12, ex12p, ex12p2
     assert cstats.alive() == 0
     assert cstats.values() == ['10', '11', '17']
     assert cstats.copy_constructions == 0
     assert cstats.move_constructions >= 0


 def test_alias_delay_initialization1(capture):
     """`A` only initializes its trampoline class when we inherit from it

     If we just create and use an A instance directly, the trampoline initialization is
     bypassed and we only initialize an A() instead (for performance reasons).
     """
     class B(m.A):
         def __init__(self):
             super(B, self).__init__()

         def f(self):
             print("In python f()")

     # C++ version
     with capture:
         a = m.A()
         m.call_f(a)
         del a
         pytest.gc_collect()
     assert capture == "A.f()"

     # Python version
     with capture:
         b = B()
         m.call_f(b)
         del b
         pytest.gc_collect()
     assert capture == """
         PyA.PyA()
         PyA.f()
         In python f()
         PyA.~PyA()
     """


 def test_alias_delay_initialization2(capture):
     """`A2`, unlike the above, is configured to always initialize the alias

     While the extra initialization and extra class layer has small virtual dispatch
     performance penalty, it also allows us to do more things with the trampoline
     class such as defining local variables and performing construction/destruction.
     """
     class B2(m.A2):
         def __init__(self):
             super(B2, self).__init__()

         def f(self):
             print("In python B2.f()")

     # No python subclass version
     with capture:
         a2 = m.A2()
         m.call_f(a2)
         del a2
         pytest.gc_collect()
         a3 = m.A2(1)
         m.call_f(a3)
         del a3
         pytest.gc_collect()
     assert capture == """
         PyA2.PyA2()
         PyA2.f()
         A2.f()
         PyA2.~PyA2()
         PyA2.PyA2()
         PyA2.f()
         A2.f()
         PyA2.~PyA2()
     """

     # Python subclass version
     with capture:
         b2 = B2()
         m.call_f(b2)
         del b2
         pytest.gc_collect()
     assert capture == """
         PyA2.PyA2()
         PyA2.f()
         In python B2.f()
         PyA2.~PyA2()
     """


 # PyPy: Reference count > 1 causes call with noncopyable instance
 # to fail in ncv1.print_nc()
 @pytest.unsupported_on_pypy
 @pytest.mark.skipif(not hasattr(m, "NCVirt"), reason="NCVirt test broken on ICPC")
 def test_move_support():
     class NCVirtExt(m.NCVirt):
         def get_noncopyable(self, a, b):
             # Constructs and returns a new instance:
             nc = m.NonCopyable(a * a, b * b)
             return nc

         def get_movable(self, a, b):
             # Return a referenced copy
             self.movable = m.Movable(a, b)
             return self.movable

     class NCVirtExt2(m.NCVirt):
         def get_noncopyable(self, a, b):
             # Keep a reference: this is going to throw an exception
             self.nc = m.NonCopyable(a, b)
             return self.nc

         def get_movable(self, a, b):
             # Return a new instance without storing it
             return m.Movable(a, b)

     ncv1 = NCVirtExt()
     assert ncv1.print_nc(2, 3) == "36"
     assert ncv1.print_movable(4, 5) == "9"
     ncv2 = NCVirtExt2()
     assert ncv2.print_movable(7, 7) == "14"
     # Don't check the exception message here because it differs under debug/non-debug mode
     with pytest.raises(RuntimeError):
         ncv2.print_nc(9, 9)

     nc_stats = ConstructorStats.get(m.NonCopyable)
     mv_stats = ConstructorStats.get(m.Movable)
     assert nc_stats.alive() == 1
     assert mv_stats.alive() == 1
     del ncv1, ncv2
     assert nc_stats.alive() == 0
     assert mv_stats.alive() == 0
     assert nc_stats.values() == ['4', '9', '9', '9']
     assert mv_stats.values() == ['4', '5', '7', '7']
     assert nc_stats.copy_constructions == 0
     assert mv_stats.copy_constructions == 1
     assert nc_stats.move_constructions >= 0
     assert mv_stats.move_constructions >= 0


 def test_dispatch_issue(msg):
     """#159: virtual function dispatch has problems with similar-named functions"""
     class PyClass1(m.DispatchIssue):
         def dispatch(self):
             return "Yay.."

     class PyClass2(m.DispatchIssue):
         def dispatch(self):
             with pytest.raises(RuntimeError) as excinfo:
                 super(PyClass2, self).dispatch()
             assert msg(excinfo.value) == 'Tried to call pure virtual function "Base::dispatch"'

             p = PyClass1()
             return m.dispatch_issue_go(p)

     b = PyClass2()
     assert m.dispatch_issue_go(b) == "Yay.."


 def test_override_ref():
     """#392/397: overriding reference-returning functions"""
     o = m.OverrideTest("asdf")

     # Not allowed (see associated .cpp comment)
     # i = o.str_ref()
     # assert o.str_ref() == "asdf"
     assert o.str_value() == "asdf"

     assert o.A_value().value == "hi"
     a = o.A_ref()
     assert a.value == "hi"
     a.value = "bye"
     assert a.value == "bye"


 def test_inherited_virtuals():
     class AR(m.A_Repeat):
         def unlucky_number(self):
             return 99

     class AT(m.A_Tpl):
         def unlucky_number(self):
             return 999

     obj = AR()
     assert obj.say_something(3) == "hihihi"
     assert obj.unlucky_number() == 99
     assert obj.say_everything() == "hi 99"

     obj = AT()
     assert obj.say_something(3) == "hihihi"
     assert obj.unlucky_number() == 999
     assert obj.say_everything() == "hi 999"

     for obj in [m.B_Repeat(), m.B_Tpl()]:
         assert obj.say_something(3) == "B says hi 3 times"
         assert obj.unlucky_number() == 13
         assert obj.lucky_number() == 7.0
         assert obj.say_everything() == "B says hi 1 times 13"

     for obj in [m.C_Repeat(), m.C_Tpl()]:
         assert obj.say_something(3) == "B says hi 3 times"
         assert obj.unlucky_number() == 4444
         assert obj.lucky_number() == 888.0
         assert obj.say_everything() == "B says hi 1 times 4444"

     class CR(m.C_Repeat):
         def lucky_number(self):
             return m.C_Repeat.lucky_number(self) + 1.25

     obj = CR()
     assert obj.say_something(3) == "B says hi 3 times"
     assert obj.unlucky_number() == 4444
     assert obj.lucky_number() == 889.25
     assert obj.say_everything() == "B says hi 1 times 4444"

     class CT(m.C_Tpl):
         pass

     obj = CT()
     assert obj.say_something(3) == "B says hi 3 times"
     assert obj.unlucky_number() == 4444
     assert obj.lucky_number() == 888.0
     assert obj.say_everything() == "B says hi 1 times 4444"

     class CCR(CR):
         def lucky_number(self):
             return CR.lucky_number(self) * 10

     obj = CCR()
     assert obj.say_something(3) == "B says hi 3 times"
     assert obj.unlucky_number() == 4444
     assert obj.lucky_number() == 8892.5
     assert obj.say_everything() == "B says hi 1 times 4444"

     class CCT(CT):
         def lucky_number(self):
             return CT.lucky_number(self) * 1000

     obj = CCT()
     assert obj.say_something(3) == "B says hi 3 times"
     assert obj.unlucky_number() == 4444
     assert obj.lucky_number() == 888000.0
     assert obj.say_everything() == "B says hi 1 times 4444"

     class DR(m.D_Repeat):
         def unlucky_number(self):
             return 123

         def lucky_number(self):
             return 42.0

     for obj in [m.D_Repeat(), m.D_Tpl()]:
         assert obj.say_something(3) == "B says hi 3 times"
         assert obj.unlucky_number() == 4444
         assert obj.lucky_number() == 888.0
         assert obj.say_everything() == "B says hi 1 times 4444"

     obj = DR()
     assert obj.say_something(3) == "B says hi 3 times"
     assert obj.unlucky_number() == 123
     assert obj.lucky_number() == 42.0
     assert obj.say_everything() == "B says hi 1 times 123"

     class DT(m.D_Tpl):
         def say_something(self, times):
             return "DT says:" + (' quack' * times)

         def unlucky_number(self):
             return 1234

         def lucky_number(self):
             return -4.25

     obj = DT()
     assert obj.say_something(3) == "DT says: quack quack quack"
     assert obj.unlucky_number() == 1234
     assert obj.lucky_number() == -4.25
     assert obj.say_everything() == "DT says: quack 1234"

     class DT2(DT):
         def say_something(self, times):
             return "DT2: " + ('QUACK' * times)

         def unlucky_number(self):
             return -3

     class BT(m.B_Tpl):
         def say_something(self, times):
             return "BT" * times

         def unlucky_number(self):
             return -7

         def lucky_number(self):
             return -1.375

     obj = BT()
     assert obj.say_something(3) == "BTBTBT"
     assert obj.unlucky_number() == -7
     assert obj.lucky_number() == -1.375
     assert obj.say_everything() == "BT -7"


 def test_issue_1454():
     # Fix issue #1454 (crash when acquiring/releasing GIL on another thread in Python 2.7)
     m.test_gil()
     m.test_gil_from_thread()
	import pytest

	from pybind11_tests import virtual_functions as m
	from pybind11_tests import ConstructorStats


	def test_override(capture, msg):
	class ExtendedExampleVirt(m.ExampleVirt):
	def __init__(self, state):
	super(ExtendedExampleVirt, self).__init__(state + 1)
	self.data = "Hello world"

	def run(self, value):
	print('ExtendedExampleVirt::run(%i), calling parent..' % value)
	return super(ExtendedExampleVirt, self).run(value + 1)

	def run_bool(self):
	print('ExtendedExampleVirt::run_bool()')
	return False

	def get_string1(self):
	return "override1"

	def pure_virtual(self):
	print('ExtendedExampleVirt::pure_virtual(): %s' % self.data)

	class ExtendedExampleVirt2(ExtendedExampleVirt):
	def __init__(self, state):
	super(ExtendedExampleVirt2, self).__init__(state + 1)

	def get_string2(self):
	return "override2"

	ex12 = m.ExampleVirt(10)
	with capture:
	assert m.runExampleVirt(ex12, 20) == 30
	assert capture == """
	Original implementation of ExampleVirt::run(state=10, value=20, str1=default1, str2=default2)
	""" # noqa: E501 line too long

	with pytest.raises(RuntimeError) as excinfo:
	m.runExampleVirtVirtual(ex12)
	assert msg(excinfo.value) == 'Tried to call pure virtual function "ExampleVirt::pure_virtual"'

	ex12p = ExtendedExampleVirt(10)
	with capture:
	assert m.runExampleVirt(ex12p, 20) == 32
	assert capture == """
	ExtendedExampleVirt::run(20), calling parent..
	Original implementation of ExampleVirt::run(state=11, value=21, str1=override1, str2=default2)
	""" # noqa: E501 line too long
	with capture:
	assert m.runExampleVirtBool(ex12p) is False
	assert capture == "ExtendedExampleVirt::run_bool()"
	with capture:
	m.runExampleVirtVirtual(ex12p)
	assert capture == "ExtendedExampleVirt::pure_virtual(): Hello world"

	ex12p2 = ExtendedExampleVirt2(15)
	with capture:
	assert m.runExampleVirt(ex12p2, 50) == 68
	assert capture == """
	ExtendedExampleVirt::run(50), calling parent..
	Original implementation of ExampleVirt::run(state=17, value=51, str1=override1, str2=override2)
	""" # noqa: E501 line too long

	cstats = ConstructorStats.get(m.ExampleVirt)
	assert cstats.alive() == 3
	del ex12, ex12p, ex12p2
	assert cstats.alive() == 0
	assert cstats.values() == ['10', '11', '17']
	assert cstats.copy_constructions == 0
	assert cstats.move_constructions >= 0


	def test_alias_delay_initialization1(capture):
	"""`A` only initializes its trampoline class when we inherit from it

	If we just create and use an A instance directly, the trampoline initialization is
	bypassed and we only initialize an A() instead (for performance reasons).
	"""
	class B(m.A):
	def __init__(self):
	super(B, self).__init__()

	def f(self):
	print("In python f()")

	# C++ version
	with capture:
	a = m.A()
	m.call_f(a)
	del a
	pytest.gc_collect()
	assert capture == "A.f()"

	# Python version
	with capture:
	b = B()
	m.call_f(b)
	del b
	pytest.gc_collect()
	assert capture == """
	PyA.PyA()
	PyA.f()
	In python f()
	PyA.~PyA()
	"""


	def test_alias_delay_initialization2(capture):
	"""`A2`, unlike the above, is configured to always initialize the alias

	While the extra initialization and extra class layer has small virtual dispatch
	performance penalty, it also allows us to do more things with the trampoline
	class such as defining local variables and performing construction/destruction.
	"""
	class B2(m.A2):
	def __init__(self):
	super(B2, self).__init__()

	def f(self):
	print("In python B2.f()")

	# No python subclass version
	with capture:
	a2 = m.A2()
	m.call_f(a2)
	del a2
	pytest.gc_collect()
	a3 = m.A2(1)
	m.call_f(a3)
	del a3
	pytest.gc_collect()
	assert capture == """
	PyA2.PyA2()
	PyA2.f()
	A2.f()
	PyA2.~PyA2()
	PyA2.PyA2()
	PyA2.f()
	A2.f()
	PyA2.~PyA2()
	"""

	# Python subclass version
	with capture:
	b2 = B2()
	m.call_f(b2)
	del b2
	pytest.gc_collect()
	assert capture == """
	PyA2.PyA2()
	PyA2.f()
	In python B2.f()
	PyA2.~PyA2()
	"""


	# PyPy: Reference count > 1 causes call with noncopyable instance
	# to fail in ncv1.print_nc()
	@pytest.unsupported_on_pypy
	@pytest.mark.skipif(not hasattr(m, "NCVirt"), reason="NCVirt test broken on ICPC")
	def test_move_support():
	class NCVirtExt(m.NCVirt):
	def get_noncopyable(self, a, b):
	# Constructs and returns a new instance:
	nc = m.NonCopyable(a * a, b * b)
	return nc

	def get_movable(self, a, b):
	# Return a referenced copy
	self.movable = m.Movable(a, b)
	return self.movable

	class NCVirtExt2(m.NCVirt):
	def get_noncopyable(self, a, b):
	# Keep a reference: this is going to throw an exception
	self.nc = m.NonCopyable(a, b)
	return self.nc

	def get_movable(self, a, b):
	# Return a new instance without storing it
	return m.Movable(a, b)

	ncv1 = NCVirtExt()
	assert ncv1.print_nc(2, 3) == "36"
	assert ncv1.print_movable(4, 5) == "9"
	ncv2 = NCVirtExt2()
	assert ncv2.print_movable(7, 7) == "14"
	# Don't check the exception message here because it differs under debug/non-debug mode
	with pytest.raises(RuntimeError):
	ncv2.print_nc(9, 9)

	nc_stats = ConstructorStats.get(m.NonCopyable)
	mv_stats = ConstructorStats.get(m.Movable)
	assert nc_stats.alive() == 1
	assert mv_stats.alive() == 1
	del ncv1, ncv2
	assert nc_stats.alive() == 0
	assert mv_stats.alive() == 0
	assert nc_stats.values() == ['4', '9', '9', '9']
	assert mv_stats.values() == ['4', '5', '7', '7']
	assert nc_stats.copy_constructions == 0
	assert mv_stats.copy_constructions == 1
	assert nc_stats.move_constructions >= 0
	assert mv_stats.move_constructions >= 0


	def test_dispatch_issue(msg):
	"""#159: virtual function dispatch has problems with similar-named functions"""
	class PyClass1(m.DispatchIssue):
	def dispatch(self):
	return "Yay.."

	class PyClass2(m.DispatchIssue):
	def dispatch(self):
	with pytest.raises(RuntimeError) as excinfo:
	super(PyClass2, self).dispatch()
	assert msg(excinfo.value) == 'Tried to call pure virtual function "Base::dispatch"'

	p = PyClass1()
	return m.dispatch_issue_go(p)

	b = PyClass2()
	assert m.dispatch_issue_go(b) == "Yay.."


	def test_override_ref():
	"""#392/397: overriding reference-returning functions"""
	o = m.OverrideTest("asdf")

	# Not allowed (see associated .cpp comment)
	# i = o.str_ref()
	# assert o.str_ref() == "asdf"
	assert o.str_value() == "asdf"

	assert o.A_value().value == "hi"
	a = o.A_ref()
	assert a.value == "hi"
	a.value = "bye"
	assert a.value == "bye"


	def test_inherited_virtuals():
	class AR(m.A_Repeat):
	def unlucky_number(self):
	return 99

	class AT(m.A_Tpl):
	def unlucky_number(self):
	return 999

	obj = AR()
	assert obj.say_something(3) == "hihihi"
	assert obj.unlucky_number() == 99
	assert obj.say_everything() == "hi 99"

	obj = AT()
	assert obj.say_something(3) == "hihihi"
	assert obj.unlucky_number() == 999
	assert obj.say_everything() == "hi 999"

	for obj in [m.B_Repeat(), m.B_Tpl()]:
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 13
	assert obj.lucky_number() == 7.0
	assert obj.say_everything() == "B says hi 1 times 13"

	for obj in [m.C_Repeat(), m.C_Tpl()]:
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 4444
	assert obj.lucky_number() == 888.0
	assert obj.say_everything() == "B says hi 1 times 4444"

	class CR(m.C_Repeat):
	def lucky_number(self):
	return m.C_Repeat.lucky_number(self) + 1.25

	obj = CR()
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 4444
	assert obj.lucky_number() == 889.25
	assert obj.say_everything() == "B says hi 1 times 4444"

	class CT(m.C_Tpl):
	pass

	obj = CT()
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 4444
	assert obj.lucky_number() == 888.0
	assert obj.say_everything() == "B says hi 1 times 4444"

	class CCR(CR):
	def lucky_number(self):
	return CR.lucky_number(self) * 10

	obj = CCR()
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 4444
	assert obj.lucky_number() == 8892.5
	assert obj.say_everything() == "B says hi 1 times 4444"

	class CCT(CT):
	def lucky_number(self):
	return CT.lucky_number(self) * 1000

	obj = CCT()
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 4444
	assert obj.lucky_number() == 888000.0
	assert obj.say_everything() == "B says hi 1 times 4444"

	class DR(m.D_Repeat):
	def unlucky_number(self):
	return 123

	def lucky_number(self):
	return 42.0

	for obj in [m.D_Repeat(), m.D_Tpl()]:
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 4444
	assert obj.lucky_number() == 888.0
	assert obj.say_everything() == "B says hi 1 times 4444"

	obj = DR()
	assert obj.say_something(3) == "B says hi 3 times"
	assert obj.unlucky_number() == 123
	assert obj.lucky_number() == 42.0
	assert obj.say_everything() == "B says hi 1 times 123"

	class DT(m.D_Tpl):
	def say_something(self, times):
	return "DT says:" + (' quack' * times)

	def unlucky_number(self):
	return 1234

	def lucky_number(self):
	return -4.25

	obj = DT()
	assert obj.say_something(3) == "DT says: quack quack quack"
	assert obj.unlucky_number() == 1234
	assert obj.lucky_number() == -4.25
	assert obj.say_everything() == "DT says: quack 1234"

	class DT2(DT):
	def say_something(self, times):
	return "DT2: " + ('QUACK' * times)

	def unlucky_number(self):
	return -3

	class BT(m.B_Tpl):
	def say_something(self, times):
	return "BT" * times

	def unlucky_number(self):
	return -7

	def lucky_number(self):
	return -1.375

	obj = BT()
	assert obj.say_something(3) == "BTBTBT"
	assert obj.unlucky_number() == -7
	assert obj.lucky_number() == -1.375
	assert obj.say_everything() == "BT -7"


	def test_issue_1454():
	# Fix issue #1454 (crash when acquiring/releasing GIL on another thread in Python 2.7)
	m.test_gil()
	m.test_gil_from_thread()