pybind11/example/example-virtual-functions.py
Jason Rhinelander 3f589379ec Improve constructor/destructor tracking
This commit rewrites the examples that look for constructor/destructor
calls to do so via static variable tracking rather than output parsing.

The added ConstructorStats class provides methods to keep track of
constructors and destructors, number of default/copy/move constructors,
and number of copy/move assignments.  It also provides a mechanism for
storing values (e.g. for value construction), and then allows all of
this to be checked at the end of a test by getting the statistics for a
C++ (or python mapping) class.

By not relying on the precise pattern of constructions/destructions,
but rather simply ensuring that every construction is matched with a
destruction on the same object, we ensure that everything that gets
created also gets destroyed as expected.

This replaces all of the various "std::cout << whatever" code in
constructors/destructors with
`print_created(this)`/`print_destroyed(this)`/etc. functions which
provide similar output, but now has a unified format across the
different examples, including a new ### prefix that makes mixed example
output and lifecycle events easier to distinguish.

With this change, relaxed mode is no longer needed, which enables
testing for proper destruction under MSVC, and under any other compiler
that generates code calling extra constructors, or optimizes away any
constructors.  GCC/clang are used as the baseline for move
constructors; the tests are adapted to allow more move constructors to
be evoked (but other types are constructors much have matching counts).

This commit also disables output buffering of tests, as the buffering
sometimes results in C++ output ending up in the middle of python
output (or vice versa), depending on the OS/python version.
2016-08-11 18:16:04 -04:00

136 lines
3.8 KiB
Python

#!/usr/bin/env python
from __future__ import print_function
import sys
sys.path.append('.')
from example import ExampleVirt, runExampleVirt, runExampleVirtVirtual, runExampleVirtBool
from example import A_Repeat, B_Repeat, C_Repeat, D_Repeat, A_Tpl, B_Tpl, C_Tpl, D_Tpl
from example import NCVirt, NonCopyable, Movable
class ExtendedExampleVirt(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 pure_virtual(self):
print('ExtendedExampleVirt::pure_virtual(): %s' % self.data)
ex12 = ExampleVirt(10)
print(runExampleVirt(ex12, 20))
try:
runExampleVirtVirtual(ex12)
except Exception as e:
print("Caught expected exception: " + str(e))
ex12p = ExtendedExampleVirt(10)
print(runExampleVirt(ex12p, 20))
print(runExampleVirtBool(ex12p))
runExampleVirtVirtual(ex12p)
class VI_AR(A_Repeat):
def unlucky_number(self):
return 99
class VI_AT(A_Tpl):
def unlucky_number(self):
return 999
class VI_CR(C_Repeat):
def lucky_number(self):
return C_Repeat.lucky_number(self) + 1.25
class VI_CT(C_Tpl):
pass
class VI_CCR(VI_CR):
def lucky_number(self):
return VI_CR.lucky_number(self) * 10
class VI_CCT(VI_CT):
def lucky_number(self):
return VI_CT.lucky_number(self) * 1000
class VI_DR(D_Repeat):
def unlucky_number(self):
return 123
def lucky_number(self):
return 42.0
class VI_DT(D_Tpl):
def say_something(self, times):
print("VI_DT says:" + (' quack' * times))
def unlucky_number(self):
return 1234
def lucky_number(self):
return -4.25
classes = [
# A_Repeat, A_Tpl, # abstract (they have a pure virtual unlucky_number)
VI_AR, VI_AT,
B_Repeat, B_Tpl,
C_Repeat, C_Tpl,
VI_CR, VI_CT, VI_CCR, VI_CCT,
D_Repeat, D_Tpl, VI_DR, VI_DT
]
for cl in classes:
print("\n%s:" % cl.__name__)
obj = cl()
obj.say_something(3)
print("Unlucky = %d" % obj.unlucky_number())
if hasattr(obj, "lucky_number"):
print("Lucky = %.2f" % obj.lucky_number())
class NCVirtExt(NCVirt):
def get_noncopyable(self, a, b):
# Constructs and returns a new instance:
nc = NonCopyable(a*a, b*b)
return nc
def get_movable(self, a, b):
# Return a referenced copy
self.movable = Movable(a, b)
return self.movable
class NCVirtExt2(NCVirt):
def get_noncopyable(self, a, b):
# Keep a reference: this is going to throw an exception
self.nc = NonCopyable(a, b)
return self.nc
def get_movable(self, a, b):
# Return a new instance without storing it
return Movable(a, b)
ncv1 = NCVirtExt()
print("2^2 * 3^2 =")
ncv1.print_nc(2, 3)
print("4 + 5 =")
ncv1.print_movable(4, 5)
ncv2 = NCVirtExt2()
print("7 + 7 =")
ncv2.print_movable(7, 7)
try:
ncv2.print_nc(9, 9)
print("Something's wrong: exception not raised!")
except RuntimeError as e:
# Don't print the exception message here because it differs under debug/non-debug mode
print("Caught expected exception")
from example import ConstructorStats
del ex12
del ex12p
del obj
del ncv1
del ncv2
cstats = [ConstructorStats.get(ExampleVirt), ConstructorStats.get(NonCopyable), ConstructorStats.get(Movable)]
print("Instances not destroyed:", [x.alive() for x in cstats])
print("Constructor values:", [x.values() for x in cstats])
print("Copy constructions:", [x.copy_constructions for x in cstats])
print("Move constructions:", [cstats[i].move_constructions >= 1 for i in range(1, len(cstats))])