Ignore deprecation warnings about old-style __init__/__setstate__ constructors in the tests (originally done in #2746) (#2759)

* Ignore old-style __init__ warnings

* Simplify ignoreOldStyleInitWarnings with py::exec

* Only wrap single class_::defs to ignore DeprecationWarnings about old-style __init__

Author: YannickJadoul

tests/pybind11_tests.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <pybind11/pybind11.h>
+#include <pybind11/eval.h>
 
 #if defined(_MSC_VER) && _MSC_VER < 1910
 // We get some really long type names here which causes MSVC 2015 to emit warnings
@@ -69,3 +70,15 @@ template<> class type_caster<RValueCaster> {
 };
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(pybind11)
+
+template <typename F>
+void ignoreOldStyleInitWarnings(F &&body) {
+    py::exec(R"(
+    message = "pybind11-bound class '.+' is using an old-style placement-new '(?:__init__|__setstate__)' which has been deprecated"
+
+    import warnings
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore", message=message, category=FutureWarning)
+        body()
+    )", py::dict(py::arg("body") = py::cpp_function(body)));
+}

tests/test_factory_constructors.cpp

@@ -183,11 +183,14 @@ TEST_SUBMODULE(factory_constructors, m) {
     auto c4a = [c](pointer_tag, TF4_tag, int a) { (void) c; return new TestFactory4(a);};
 
     // test_init_factory_basic, test_init_factory_casting
-    py::class_<TestFactory3, std::shared_ptr<TestFactory3>>(m, "TestFactory3")
+    py::class_<TestFactory3, std::shared_ptr<TestFactory3>> pyTestFactory3(m, "TestFactory3");
+    pyTestFactory3
         .def(py::init([](pointer_tag, int v) { return TestFactoryHelper::construct3(v); }))
-        .def(py::init([](shared_ptr_tag) { return TestFactoryHelper::construct3(); }))
-        .def("__init__", [](TestFactory3 &self, std::string v) { new (&self) TestFactory3(v); }) // placement-new ctor
-
+        .def(py::init([](shared_ptr_tag) { return TestFactoryHelper::construct3(); }));
+    ignoreOldStyleInitWarnings([&pyTestFactory3]() {
+        pyTestFactory3.def("__init__", [](TestFactory3 &self, std::string v) { new (&self) TestFactory3(v); }); // placement-new ctor
+    });
+    pyTestFactory3
         // factories returning a derived type:
         .def(py::init(c4a)) // derived ptr
         .def(py::init([](pointer_tag, TF5_tag, int a) { return new TestFactory5(a); }))
@@ -304,24 +307,32 @@ TEST_SUBMODULE(factory_constructors, m) {
         static void operator delete(void *p) { py::print("noisy delete"); ::operator delete(p); }
 #endif
     };
-    py::class_<NoisyAlloc>(m, "NoisyAlloc")
+
+
+    py::class_<NoisyAlloc> pyNoisyAlloc(m, "NoisyAlloc");
         // Since these overloads have the same number of arguments, the dispatcher will try each of
         // them until the arguments convert.  Thus we can get a pre-allocation here when passing a
         // single non-integer:
-        .def("__init__", [](NoisyAlloc *a, int i) { new (a) NoisyAlloc(i); }) // Regular constructor, runs first, requires preallocation
-        .def(py::init([](double d) { return new NoisyAlloc(d); }))
-
-        // The two-argument version: first the factory pointer overload.
-        .def(py::init([](int i, int) { return new NoisyAlloc(i); }))
-        // Return-by-value:
-        .def(py::init([](double d, int) { return NoisyAlloc(d); }))
-        // Old-style placement new init; requires preallocation
-        .def("__init__", [](NoisyAlloc &a, double d, double) { new (&a) NoisyAlloc(d); })
-        // Requires deallocation of previous overload preallocated value:
-        .def(py::init([](int i, double) { return new NoisyAlloc(i); }))
-        // Regular again: requires yet another preallocation
-        .def("__init__", [](NoisyAlloc &a, int i, std::string) { new (&a) NoisyAlloc(i); })
-        ;
+    ignoreOldStyleInitWarnings([&pyNoisyAlloc]() {
+        pyNoisyAlloc.def("__init__", [](NoisyAlloc *a, int i) { new (a) NoisyAlloc(i); }); // Regular constructor, runs first, requires preallocation
+    });
+
+    pyNoisyAlloc.def(py::init([](double d) { return new NoisyAlloc(d); }));
+
+    // The two-argument version: first the factory pointer overload.
+    pyNoisyAlloc.def(py::init([](int i, int) { return new NoisyAlloc(i); }));
+    // Return-by-value:
+    pyNoisyAlloc.def(py::init([](double d, int) { return NoisyAlloc(d); }));
+    // Old-style placement new init; requires preallocation
+    ignoreOldStyleInitWarnings([&pyNoisyAlloc]() {
+        pyNoisyAlloc.def("__init__", [](NoisyAlloc &a, double d, double) { new (&a) NoisyAlloc(d); });
+    });
+    // Requires deallocation of previous overload preallocated value:
+    pyNoisyAlloc.def(py::init([](int i, double) { return new NoisyAlloc(i); }));
+    // Regular again: requires yet another preallocation
+    ignoreOldStyleInitWarnings([&pyNoisyAlloc]() {
+        pyNoisyAlloc.def("__init__", [](NoisyAlloc &a, int i, std::string) { new (&a) NoisyAlloc(i); });
+    });
 
 
 

tests/test_pickling.cpp

@@ -31,7 +31,8 @@ TEST_SUBMODULE(pickling, m) {
         using Pickleable::Pickleable;
     };
 
-    py::class_<Pickleable>(m, "Pickleable")
+    py::class_<Pickleable> pyPickleable(m, "Pickleable");
+    pyPickleable
         .def(py::init<std::string>())
         .def("value", &Pickleable::value)
         .def("extra1", &Pickleable::extra1)
@@ -43,17 +44,20 @@ TEST_SUBMODULE(pickling, m) {
         .def("__getstate__", [](const Pickleable &p) {
             /* Return a tuple that fully encodes the state of the object */
             return py::make_tuple(p.value(), p.extra1(), p.extra2());
-        })
-        .def("__setstate__", [](Pickleable &p, py::tuple t) {
-            if (t.size() != 3)
-                throw std::runtime_error("Invalid state!");
-            /* Invoke the constructor (need to use in-place version) */
-            new (&p) Pickleable(t[0].cast<std::string>());
-
-            /* Assign any additional state */
-            p.setExtra1(t[1].cast<int>());
-            p.setExtra2(t[2].cast<int>());
         });
+    ignoreOldStyleInitWarnings([&pyPickleable]() {
+        pyPickleable
+            .def("__setstate__", [](Pickleable &p, py::tuple t) {
+                if (t.size() != 3)
+                    throw std::runtime_error("Invalid state!");
+                /* Invoke the constructor (need to use in-place version) */
+                new (&p) Pickleable(t[0].cast<std::string>());
+
+                /* Assign any additional state */
+                p.setExtra1(t[1].cast<int>());
+                p.setExtra2(t[2].cast<int>());
+            });
+    });
 
     py::class_<PickleableNew, Pickleable>(m, "PickleableNew")
         .def(py::init<std::string>())
@@ -87,27 +91,31 @@ TEST_SUBMODULE(pickling, m) {
         using PickleableWithDict::PickleableWithDict;
     };
 
-    py::class_<PickleableWithDict>(m, "PickleableWithDict", py::dynamic_attr())
+    py::class_<PickleableWithDict> pyPickleableWithDict(m, "PickleableWithDict", py::dynamic_attr());
+    pyPickleableWithDict
         .def(py::init<std::string>())
         .def_readwrite("value", &PickleableWithDict::value)
         .def_readwrite("extra", &PickleableWithDict::extra)
         .def("__getstate__", [](py::object self) {
             /* Also include __dict__ in state */
             return py::make_tuple(self.attr("value"), self.attr("extra"), self.attr("__dict__"));
-        })
-        .def("__setstate__", [](py::object self, py::tuple t) {
-            if (t.size() != 3)
-                throw std::runtime_error("Invalid state!");
-            /* Cast and construct */
-            auto& p = self.cast<PickleableWithDict&>();
-            new (&p) PickleableWithDict(t[0].cast<std::string>());
-
-            /* Assign C++ state */
-            p.extra = t[1].cast<int>();
-
-            /* Assign Python state */
-            self.attr("__dict__") = t[2];
         });
+    ignoreOldStyleInitWarnings([&pyPickleableWithDict]() {
+        pyPickleableWithDict
+            .def("__setstate__", [](py::object self, py::tuple t) {
+                if (t.size() != 3)
+                    throw std::runtime_error("Invalid state!");
+                /* Cast and construct */
+                auto& p = self.cast<PickleableWithDict&>();
+                new (&p) PickleableWithDict(t[0].cast<std::string>());
+
+                /* Assign C++ state */
+                p.extra = t[1].cast<int>();
+
+                /* Assign Python state */
+                self.attr("__dict__") = t[2];
+            });
+    });
 
     py::class_<PickleableWithDictNew, PickleableWithDict>(m, "PickleableWithDictNew")
         .def(py::init<std::string>())