summaryrefslogtreecommitdiff
path: root/ext/pybind11/tests/test_virtual_functions.cpp
blob: ccf018d997041c543a4dc4aec5875a6dca7c6914 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
/*
    tests/test_virtual_functions.cpp -- overriding virtual functions from Python

    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>

    All rights reserved. Use of this source code is governed by a
    BSD-style license that can be found in the LICENSE file.
*/

#include "pybind11_tests.h"
#include "constructor_stats.h"
#include <pybind11/functional.h>
#include <thread>

/* This is an example class that we'll want to be able to extend from Python */
class ExampleVirt  {
public:
    ExampleVirt(int state) : state(state) { print_created(this, state); }
    ExampleVirt(const ExampleVirt &e) : state(e.state) { print_copy_created(this); }
    ExampleVirt(ExampleVirt &&e) : state(e.state) { print_move_created(this); e.state = 0; }
    virtual ~ExampleVirt() { print_destroyed(this); }

    virtual int run(int value) {
        py::print("Original implementation of "
                  "ExampleVirt::run(state={}, value={}, str1={}, str2={})"_s.format(state, value, get_string1(), *get_string2()));
        return state + value;
    }

    virtual bool run_bool() = 0;
    virtual void pure_virtual() = 0;

    // Returning a reference/pointer to a type converted from python (numbers, strings, etc.) is a
    // bit trickier, because the actual int& or std::string& or whatever only exists temporarily, so
    // we have to handle it specially in the trampoline class (see below).
    virtual const std::string &get_string1() { return str1; }
    virtual const std::string *get_string2() { return &str2; }

private:
    int state;
    const std::string str1{"default1"}, str2{"default2"};
};

/* This is a wrapper class that must be generated */
class PyExampleVirt : public ExampleVirt {
public:
    using ExampleVirt::ExampleVirt; /* Inherit constructors */

    int run(int value) override {
        /* Generate wrapping code that enables native function overloading */
        PYBIND11_OVERLOAD(
            int,         /* Return type */
            ExampleVirt, /* Parent class */
            run,         /* Name of function */
            value        /* Argument(s) */
        );
    }

    bool run_bool() override {
        PYBIND11_OVERLOAD_PURE(
            bool,         /* Return type */
            ExampleVirt,  /* Parent class */
            run_bool,     /* Name of function */
                          /* This function has no arguments. The trailing comma
                             in the previous line is needed for some compilers */
        );
    }

    void pure_virtual() override {
        PYBIND11_OVERLOAD_PURE(
            void,         /* Return type */
            ExampleVirt,  /* Parent class */
            pure_virtual, /* Name of function */
                          /* This function has no arguments. The trailing comma
                             in the previous line is needed for some compilers */
        );
    }

    // We can return reference types for compatibility with C++ virtual interfaces that do so, but
    // note they have some significant limitations (see the documentation).
    const std::string &get_string1() override {
        PYBIND11_OVERLOAD(
            const std::string &, /* Return type */
            ExampleVirt,         /* Parent class */
            get_string1,         /* Name of function */
                                 /* (no arguments) */
        );
    }

    const std::string *get_string2() override {
        PYBIND11_OVERLOAD(
            const std::string *, /* Return type */
            ExampleVirt,         /* Parent class */
            get_string2,         /* Name of function */
                                 /* (no arguments) */
        );
    }

};

class NonCopyable {
public:
    NonCopyable(int a, int b) : value{new int(a*b)} { print_created(this, a, b); }
    NonCopyable(NonCopyable &&o) { value = std::move(o.value); print_move_created(this); }
    NonCopyable(const NonCopyable &) = delete;
    NonCopyable() = delete;
    void operator=(const NonCopyable &) = delete;
    void operator=(NonCopyable &&) = delete;
    std::string get_value() const {
        if (value) return std::to_string(*value); else return "(null)";
    }
    ~NonCopyable() { print_destroyed(this); }

private:
    std::unique_ptr<int> value;
};

// This is like the above, but is both copy and movable.  In effect this means it should get moved
// when it is not referenced elsewhere, but copied if it is still referenced.
class Movable {
public:
    Movable(int a, int b) : value{a+b} { print_created(this, a, b); }
    Movable(const Movable &m) { value = m.value; print_copy_created(this); }
    Movable(Movable &&m) { value = std::move(m.value); print_move_created(this); }
    std::string get_value() const { return std::to_string(value); }
    ~Movable() { print_destroyed(this); }
private:
    int value;
};

class NCVirt {
public:
    virtual ~NCVirt() { }
    virtual NonCopyable get_noncopyable(int a, int b) { return NonCopyable(a, b); }
    virtual Movable get_movable(int a, int b) = 0;

    std::string print_nc(int a, int b) { return get_noncopyable(a, b).get_value(); }
    std::string print_movable(int a, int b) { return get_movable(a, b).get_value(); }
};
class NCVirtTrampoline : public NCVirt {
#if !defined(__INTEL_COMPILER)
    NonCopyable get_noncopyable(int a, int b) override {
        PYBIND11_OVERLOAD(NonCopyable, NCVirt, get_noncopyable, a, b);
    }
#endif
    Movable get_movable(int a, int b) override {
        PYBIND11_OVERLOAD_PURE(Movable, NCVirt, get_movable, a, b);
    }
};

struct Base {
    /* for some reason MSVC2015 can't compile this if the function is pure virtual */
    virtual std::string dispatch() const { return {}; };
    virtual ~Base() = default;
};

struct DispatchIssue : Base {
    virtual std::string dispatch() const {
        PYBIND11_OVERLOAD_PURE(std::string, Base, dispatch, /* no arguments */);
    }
};

static void test_gil() {
    {
        py::gil_scoped_acquire lock;
        py::print("1st lock acquired");

    }

    {
        py::gil_scoped_acquire lock;
        py::print("2nd lock acquired");
    }

}

static void test_gil_from_thread() {
    py::gil_scoped_release release;

    std::thread t(test_gil);
    t.join();
}


// Forward declaration (so that we can put the main tests here; the inherited virtual approaches are
// rather long).
void initialize_inherited_virtuals(py::module &m);

TEST_SUBMODULE(virtual_functions, m) {
    // test_override
    py::class_<ExampleVirt, PyExampleVirt>(m, "ExampleVirt")
        .def(py::init<int>())
        /* Reference original class in function definitions */
        .def("run", &ExampleVirt::run)
        .def("run_bool", &ExampleVirt::run_bool)
        .def("pure_virtual", &ExampleVirt::pure_virtual);

    py::class_<NonCopyable>(m, "NonCopyable")
        .def(py::init<int, int>());

    py::class_<Movable>(m, "Movable")
        .def(py::init<int, int>());

    // test_move_support
#if !defined(__INTEL_COMPILER)
    py::class_<NCVirt, NCVirtTrampoline>(m, "NCVirt")
        .def(py::init<>())
        .def("get_noncopyable", &NCVirt::get_noncopyable)
        .def("get_movable", &NCVirt::get_movable)
        .def("print_nc", &NCVirt::print_nc)
        .def("print_movable", &NCVirt::print_movable);
#endif

    m.def("runExampleVirt", [](ExampleVirt *ex, int value) { return ex->run(value); });
    m.def("runExampleVirtBool", [](ExampleVirt* ex) { return ex->run_bool(); });
    m.def("runExampleVirtVirtual", [](ExampleVirt *ex) { ex->pure_virtual(); });

    m.def("cstats_debug", &ConstructorStats::get<ExampleVirt>);
    initialize_inherited_virtuals(m);

    // test_alias_delay_initialization1
    // don't invoke Python dispatch classes by default when instantiating C++ classes
    // that were not extended on the Python side
    struct A {
        virtual ~A() {}
        virtual void f() { py::print("A.f()"); }
    };

    struct PyA : A {
        PyA() { py::print("PyA.PyA()"); }
        ~PyA() { py::print("PyA.~PyA()"); }

        void f() override {
            py::print("PyA.f()");
            // This convolution just gives a `void`, but tests that PYBIND11_TYPE() works to protect
            // a type containing a ,
            PYBIND11_OVERLOAD(PYBIND11_TYPE(typename std::enable_if<true, void>::type), A, f);
        }
    };

    py::class_<A, PyA>(m, "A")
        .def(py::init<>())
        .def("f", &A::f);

    m.def("call_f", [](A *a) { a->f(); });

    // test_alias_delay_initialization2
    // ... unless we explicitly request it, as in this example:
    struct A2 {
        virtual ~A2() {}
        virtual void f() { py::print("A2.f()"); }
    };

    struct PyA2 : A2 {
        PyA2() { py::print("PyA2.PyA2()"); }
        ~PyA2() { py::print("PyA2.~PyA2()"); }
        void f() override {
            py::print("PyA2.f()");
            PYBIND11_OVERLOAD(void, A2, f);
        }
    };

    py::class_<A2, PyA2>(m, "A2")
        .def(py::init_alias<>())
        .def(py::init([](int) { return new PyA2(); }))
        .def("f", &A2::f);

    m.def("call_f", [](A2 *a2) { a2->f(); });

    // test_dispatch_issue
    // #159: virtual function dispatch has problems with similar-named functions
    py::class_<Base, DispatchIssue>(m, "DispatchIssue")
        .def(py::init<>())
        .def("dispatch", &Base::dispatch);

    m.def("dispatch_issue_go", [](const Base * b) { return b->dispatch(); });

    // test_override_ref
    // #392/397: overriding reference-returning functions
    class OverrideTest {
    public:
        struct A { std::string value = "hi"; };
        std::string v;
        A a;
        explicit OverrideTest(const std::string &v) : v{v} {}
        virtual std::string str_value() { return v; }
        virtual std::string &str_ref() { return v; }
        virtual A A_value() { return a; }
        virtual A &A_ref() { return a; }
        virtual ~OverrideTest() = default;
    };

    class PyOverrideTest : public OverrideTest {
    public:
        using OverrideTest::OverrideTest;
        std::string str_value() override { PYBIND11_OVERLOAD(std::string, OverrideTest, str_value); }
        // Not allowed (uncommenting should hit a static_assert failure): we can't get a reference
        // to a python numeric value, since we only copy values in the numeric type caster:
//      std::string &str_ref() override { PYBIND11_OVERLOAD(std::string &, OverrideTest, str_ref); }
        // But we can work around it like this:
    private:
        std::string _tmp;
        std::string str_ref_helper() { PYBIND11_OVERLOAD(std::string, OverrideTest, str_ref); }
    public:
        std::string &str_ref() override { return _tmp = str_ref_helper(); }

        A A_value() override { PYBIND11_OVERLOAD(A, OverrideTest, A_value); }
        A &A_ref() override { PYBIND11_OVERLOAD(A &, OverrideTest, A_ref); }
    };

    py::class_<OverrideTest::A>(m, "OverrideTest_A")
        .def_readwrite("value", &OverrideTest::A::value);
    py::class_<OverrideTest, PyOverrideTest>(m, "OverrideTest")
        .def(py::init<const std::string &>())
        .def("str_value", &OverrideTest::str_value)
//      .def("str_ref", &OverrideTest::str_ref)
        .def("A_value", &OverrideTest::A_value)
        .def("A_ref", &OverrideTest::A_ref);
}


// Inheriting virtual methods.  We do two versions here: the repeat-everything version and the
// templated trampoline versions mentioned in docs/advanced.rst.
//
// These base classes are exactly the same, but we technically need distinct
// classes for this example code because we need to be able to bind them
// properly (pybind11, sensibly, doesn't allow us to bind the same C++ class to
// multiple python classes).
class A_Repeat {
#define A_METHODS \
public: \
    virtual int unlucky_number() = 0; \
    virtual std::string say_something(unsigned times) { \
        std::string s = ""; \
        for (unsigned i = 0; i < times; ++i) \
            s += "hi"; \
        return s; \
    } \
    std::string say_everything() { \
        return say_something(1) + " " + std::to_string(unlucky_number()); \
    }
A_METHODS
    virtual ~A_Repeat() = default;
};
class B_Repeat : public A_Repeat {
#define B_METHODS \
public: \
    int unlucky_number() override { return 13; } \
    std::string say_something(unsigned times) override { \
        return "B says hi " + std::to_string(times) + " times"; \
    } \
    virtual double lucky_number() { return 7.0; }
B_METHODS
};
class C_Repeat : public B_Repeat {
#define C_METHODS \
public: \
    int unlucky_number() override { return 4444; } \
    double lucky_number() override { return 888; }
C_METHODS
};
class D_Repeat : public C_Repeat {
#define D_METHODS // Nothing overridden.
D_METHODS
};

// Base classes for templated inheritance trampolines.  Identical to the repeat-everything version:
class A_Tpl { A_METHODS; virtual ~A_Tpl() = default; };
class B_Tpl : public A_Tpl { B_METHODS };
class C_Tpl : public B_Tpl { C_METHODS };
class D_Tpl : public C_Tpl { D_METHODS };


// Inheritance approach 1: each trampoline gets every virtual method (11 in total)
class PyA_Repeat : public A_Repeat {
public:
    using A_Repeat::A_Repeat;
    int unlucky_number() override { PYBIND11_OVERLOAD_PURE(int, A_Repeat, unlucky_number, ); }
    std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, A_Repeat, say_something, times); }
};
class PyB_Repeat : public B_Repeat {
public:
    using B_Repeat::B_Repeat;
    int unlucky_number() override { PYBIND11_OVERLOAD(int, B_Repeat, unlucky_number, ); }
    std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, B_Repeat, say_something, times); }
    double lucky_number() override { PYBIND11_OVERLOAD(double, B_Repeat, lucky_number, ); }
};
class PyC_Repeat : public C_Repeat {
public:
    using C_Repeat::C_Repeat;
    int unlucky_number() override { PYBIND11_OVERLOAD(int, C_Repeat, unlucky_number, ); }
    std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, C_Repeat, say_something, times); }
    double lucky_number() override { PYBIND11_OVERLOAD(double, C_Repeat, lucky_number, ); }
};
class PyD_Repeat : public D_Repeat {
public:
    using D_Repeat::D_Repeat;
    int unlucky_number() override { PYBIND11_OVERLOAD(int, D_Repeat, unlucky_number, ); }
    std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, D_Repeat, say_something, times); }
    double lucky_number() override { PYBIND11_OVERLOAD(double, D_Repeat, lucky_number, ); }
};

// Inheritance approach 2: templated trampoline classes.
//
// Advantages:
// - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one for
//   any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes and 11
//   methods (repeat).
// - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and can
//   properly inherit constructors.
//
// Disadvantage:
// - the compiler must still generate and compile 14 different methods (more, even, than the 11
//   required for the repeat approach) instead of the 6 required for MI.  (If there was no pure
//   method (or no pure method override), the number would drop down to the same 11 as the repeat
//   approach).
template <class Base = A_Tpl>
class PyA_Tpl : public Base {
public:
    using Base::Base; // Inherit constructors
    int unlucky_number() override { PYBIND11_OVERLOAD_PURE(int, Base, unlucky_number, ); }
    std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, Base, say_something, times); }
};
template <class Base = B_Tpl>
class PyB_Tpl : public PyA_Tpl<Base> {
public:
    using PyA_Tpl<Base>::PyA_Tpl; // Inherit constructors (via PyA_Tpl's inherited constructors)
    int unlucky_number() override { PYBIND11_OVERLOAD(int, Base, unlucky_number, ); }
    double lucky_number() override { PYBIND11_OVERLOAD(double, Base, lucky_number, ); }
};
// Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these (we can
// use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead):
/*
template <class Base = C_Tpl> class PyC_Tpl : public PyB_Tpl<Base> {
public:
    using PyB_Tpl<Base>::PyB_Tpl;
};
template <class Base = D_Tpl> class PyD_Tpl : public PyC_Tpl<Base> {
public:
    using PyC_Tpl<Base>::PyC_Tpl;
};
*/

void initialize_inherited_virtuals(py::module &m) {
    // test_inherited_virtuals

    // Method 1: repeat
    py::class_<A_Repeat, PyA_Repeat>(m, "A_Repeat")
        .def(py::init<>())
        .def("unlucky_number", &A_Repeat::unlucky_number)
        .def("say_something", &A_Repeat::say_something)
        .def("say_everything", &A_Repeat::say_everything);
    py::class_<B_Repeat, A_Repeat, PyB_Repeat>(m, "B_Repeat")
        .def(py::init<>())
        .def("lucky_number", &B_Repeat::lucky_number);
    py::class_<C_Repeat, B_Repeat, PyC_Repeat>(m, "C_Repeat")
        .def(py::init<>());
    py::class_<D_Repeat, C_Repeat, PyD_Repeat>(m, "D_Repeat")
        .def(py::init<>());

    // test_
    // Method 2: Templated trampolines
    py::class_<A_Tpl, PyA_Tpl<>>(m, "A_Tpl")
        .def(py::init<>())
        .def("unlucky_number", &A_Tpl::unlucky_number)
        .def("say_something", &A_Tpl::say_something)
        .def("say_everything", &A_Tpl::say_everything);
    py::class_<B_Tpl, A_Tpl, PyB_Tpl<>>(m, "B_Tpl")
        .def(py::init<>())
        .def("lucky_number", &B_Tpl::lucky_number);
    py::class_<C_Tpl, B_Tpl, PyB_Tpl<C_Tpl>>(m, "C_Tpl")
        .def(py::init<>());
    py::class_<D_Tpl, C_Tpl, PyB_Tpl<D_Tpl>>(m, "D_Tpl")
        .def(py::init<>());


    // Fix issue #1454 (crash when acquiring/releasing GIL on another thread in Python 2.7)
    m.def("test_gil", &test_gil);
    m.def("test_gil_from_thread", &test_gil_from_thread);
};