WIP cross module exception ODR experiments

tests/CMakeLists.txt

@@ -125,6 +125,8 @@ set(PYBIND11_TEST_FILES
     test_const_name
     test_constants_and_functions
     test_copy_move
+    test_cross_module_exception_odr_1.py
+    test_cross_module_exception_odr_2.py
     test_custom_type_casters
     test_custom_type_setup
     test_docstring_options
@@ -219,6 +221,8 @@ tests_extra_targets("test_exceptions.py;test_local_bindings.py;test_stl.py;test_
 # And add additional targets for other tests.
 tests_extra_targets("test_exceptions.py" "cross_module_interleaved_error_already_set")
 tests_extra_targets("test_gil_scoped.py" "cross_module_gil_utils")
+tests_extra_targets("test_cross_module_exception_odr_1.py" "cross_module_exception_odr_1")
+tests_extra_targets("test_cross_module_exception_odr_2.py" "cross_module_exception_odr_2")
 
 set(PYBIND11_EIGEN_REPO
     "https://gitlab.com/libeigen/eigen.git"

tests/conftest.py

@@ -4,6 +4,13 @@
 Adds docstring and exceptions message sanitizers.
 """
 
+import sys
+
+if sys.platform == "linux":
+    sys.setdlopenflags(0x100 | 0x2)  # RTLD_GLOBAL | RTLD_NOW
+elif sys.platform == "darwin":
+    sys.setdlopenflags(0x8 | 0x2)  # RTLD_GLOBAL | RTLD_NOW
+
 import contextlib
 import difflib
 import gc

tests/cross_module_exception_odr_1.cpp

@@ -0,0 +1,42 @@
+#include "pybind11/pybind11.h"
+
+#include <exception>
+
+namespace cross_module_exception_odr {
+
+#if defined(_MSC_VER)
+#    pragma warning(push)
+#    pragma warning(disable : 4275)
+#endif
+
+class PYBIND11_EXPORT_EXCEPTION evolving : public std::runtime_error {
+public:
+    explicit evolving(const std::string &msg) : std::runtime_error("v1:" + msg) {}
+};
+
+#if defined(_MSC_VER)
+#    pragma warning(pop)
+#endif
+
+} // namespace cross_module_exception_odr
+
+PYBIND11_MODULE(cross_module_exception_odr_1, m) {
+    using namespace cross_module_exception_odr;
+    namespace py = pybind11;
+
+    py::register_exception_translator([](std::exception_ptr p) {
+        try {
+            if (p) {
+                std::rethrow_exception(p);
+            }
+        } catch (const evolving &e) {
+            PyErr_SetString(PyExc_RuntimeError, e.what());
+        }
+    });
+
+    m.def("raise_evolving", [](const std::string &msg) { throw evolving(msg); });
+    m.def("raise_evolving_from_module_2", [](const py::capsule &cap) {
+        auto f = reinterpret_cast<void (*)()>(cap.get_pointer<void>());
+        f();
+    });
+}

tests/cross_module_exception_odr_2.cpp

@@ -0,0 +1,44 @@
+#include "pybind11/pybind11.h"
+
+#include <exception>
+
+namespace cross_module_exception_odr {
+
+#if defined(_MSC_VER)
+#    pragma warning(push)
+#    pragma warning(disable : 4275)
+#endif
+
+class PYBIND11_EXPORT_EXCEPTION evolving : public std::exception {
+public:
+    const char *what() const noexcept override { return "v2"; }
+};
+
+#if defined(_MSC_VER)
+#    pragma warning(pop)
+#endif
+
+void raise_evolving_from_module_2() { throw evolving(); }
+
+} // namespace cross_module_exception_odr
+
+PYBIND11_MODULE(cross_module_exception_odr_2, m) {
+    using namespace cross_module_exception_odr;
+    namespace py = pybind11;
+
+    py::register_exception_translator([](std::exception_ptr p) {
+        try {
+            if (p) {
+                std::rethrow_exception(p);
+            }
+        } catch (const evolving &e) {
+            PyErr_SetString(PyExc_RuntimeError, e.what());
+        }
+    });
+
+    m.def("raise_evolving", []() { throw evolving(); });
+    m.def("get_raise_evolving_from_module_2_capsule", []() {
+        return py::capsule(reinterpret_cast<void *>(&raise_evolving_from_module_2),
+                           "raise_evolving_from_module_2_function_pointer");
+    });
+}

tests/test_cross_module_exception_odr_1.py

@@ -0,0 +1,14 @@
+import cross_module_exception_odr_1 as m
+import cross_module_exception_odr_2 as m2
+import pytest
+
+
+def test_raise_evolving():
+    with pytest.raises(RuntimeError, match="v1:t1"):
+        m.raise_evolving("t1")
+
+
+def test_raise_evolving_from_module_2():
+    cap = m2.get_raise_evolving_from_module_2_capsule()
+    with pytest.raises(RuntimeError, match="v2"):
+        m.raise_evolving_from_module_2(cap)

tests/test_cross_module_exception_odr_2.py

@@ -0,0 +1,7 @@
+import cross_module_exception_odr_2 as m
+import pytest
+
+
+def test_raise_evolving():
+    with pytest.raises(RuntimeError, match="v2"):
+        m.raise_evolving()