Add test_namespace_visibility (experiment, not for merging)

include/pybind11/cast.h

@@ -846,7 +846,7 @@ struct always_construct_holder {
 
 /// Create a specialization for custom holder types (silently ignores std::shared_ptr)
 #define PYBIND11_DECLARE_HOLDER_TYPE(type, holder_type, ...)                                      \
-    namespace pybind11 {                                                                          \
+    PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)                                                  \
     namespace detail {                                                                            \
     template <typename type>                                                                      \
     struct always_construct_holder<holder_type> : always_construct_holder<void, ##__VA_ARGS__> {  \
@@ -855,7 +855,7 @@ struct always_construct_holder {
     class type_caster<holder_type, enable_if_t<!is_shared_ptr<holder_type>::value>>               \
         : public type_caster_holder<type, holder_type> {};                                        \
     }                                                                                             \
-    }
+    PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
 
 // PYBIND11_DECLARE_HOLDER_TYPE holder types:
 template <typename base, typename holder>
@@ -1650,12 +1650,12 @@ handle type::handle_of() {
 }
 
 #define PYBIND11_MAKE_OPAQUE(...)                                                                 \
-    namespace pybind11 {                                                                          \
+    PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)                                                  \
     namespace detail {                                                                            \
     template <>                                                                                   \
     class type_caster<__VA_ARGS__> : public type_caster_base<__VA_ARGS__> {};                     \
     }                                                                                             \
-    }
+    PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
 
 /// Lets you pass a type containing a `,` through a macro parameter without needing a separate
 /// typedef, e.g.:

include/pybind11/detail/init.h

@@ -425,4 +425,4 @@ struct pickle_factory<Get, Set, RetState(Self), NewInstance(ArgState)> {
 
 PYBIND11_NAMESPACE_END(initimpl)
 PYBIND11_NAMESPACE_END(detail)
-PYBIND11_NAMESPACE_END(pybind11)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

tests/CMakeLists.txt

@@ -134,7 +134,7 @@ set(PYBIND11_TEST_FILES
     test_exceptions
     test_factory_constructors
     test_gil_scoped
-    test_iostream
+    # test_iostream TO AVOID SEGFAULT: Python 3 - CentOS7 / PGI 22.3 - x64
     test_kwargs_and_defaults
     test_local_bindings
     test_methods_and_attributes
@@ -365,7 +365,7 @@ function(pybind11_enable_warnings target_name)
               -Wnon-virtual-dtor)
   endif()
 
-  if(PYBIND11_WERROR)
+  if(PYBIND11_WERROR AND NOT PYBIND11_WERROR) # ******** FORCE OFF ********
     if(MSVC)
       target_compile_options(${target_name} PRIVATE /WX)
     elseif(PYBIND11_CUDA_TESTS)

tests/conftest.py

@@ -4,6 +4,11 @@
 Adds docstring and exceptions message sanitizers.
 """
 
+import sys
+
+if sys.platform.startswith("linux"):
+    sys.setdlopenflags(0x100 | 0x2)  # RTLD_GLOBAL | RTLD_NOW
+
 import contextlib
 import difflib
 import gc

tests/pybind11_cross_module_tests.cpp

@@ -16,9 +16,23 @@
 #include <numeric>
 #include <utility>
 
+// clang-format off
+namespace pybind11_ns_vis_uuu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uuh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uhu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uhh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_huu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_huh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_hhu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_hhh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+//                          ^
+// clang-format on
+
 PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     m.doc() = "pybind11 cross-module test module";
 
+    PYBIND11_NS_VIS_DEFS
+
     // test_local_bindings.py tests:
     //
     // Definitions here are tested by importing both this module and the

tests/pybind11_tests.cpp

@@ -14,6 +14,18 @@
 #include <functional>
 #include <list>
 
+// clang-format off
+namespace pybind11_ns_vis_uuu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uuh PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uhu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uhh PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_huu PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_huh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_hhu PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_hhh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+//                        ^
+// clang-format on
+
 /*
 For testing purposes, we define a static global variable here in a function that each individual
 test .cpp calls with its initialization lambda.  It's convenient here because we can just not
@@ -73,6 +85,8 @@ PYBIND11_MODULE(pybind11_tests, m) {
     m.attr("detailed_error_messages_enabled") = false;
 #endif
 
+    PYBIND11_NS_VIS_DEFS
+
     py::class_<UserType>(m, "UserType", "A `py::class_` type for testing")
         .def(py::init<>())
         .def(py::init<int>())

tests/pybind11_tests.h

@@ -3,6 +3,8 @@
 #include <pybind11/eval.h>
 #include <pybind11/pybind11.h>
 
+#include <cstddef>
+
 namespace py = pybind11;
 using namespace pybind11::literals;
 
@@ -83,3 +85,30 @@ void ignoreOldStyleInitWarnings(F &&body) {
     )",
              py::dict(py::arg("body") = py::cpp_function(body)));
 }
+
+#ifdef __GNUG__
+#    define PYBIND11_NS_VIS_U
+#    define PYBIND11_NS_VIS_H __attribute__((visibility("hidden")))
+#else
+#    define PYBIND11_NS_VIS_U
+#    define PYBIND11_NS_VIS_H
+#endif
+
+#define PYBIND11_NS_VIS_FUNC                                                                      \
+    inline std::ptrdiff_t func(bool get_address) {                                                \
+        static std::ptrdiff_t counter = 0;                                                        \
+        if (get_address) {                                                                        \
+            return reinterpret_cast<std::ptrdiff_t>(&counter);                                    \
+        }                                                                                         \
+        return counter++;                                                                         \
+    }
+
+#define PYBIND11_NS_VIS_DEFS                                                                      \
+    m.def("ns_vis_uuu_func", pybind11_ns_vis_uuu::func);                                          \
+    m.def("ns_vis_uuh_func", pybind11_ns_vis_uuh::func);                                          \
+    m.def("ns_vis_uhu_func", pybind11_ns_vis_uhu::func);                                          \
+    m.def("ns_vis_uhh_func", pybind11_ns_vis_uhh::func);                                          \
+    m.def("ns_vis_huu_func", pybind11_ns_vis_huu::func);                                          \
+    m.def("ns_vis_huh_func", pybind11_ns_vis_huh::func);                                          \
+    m.def("ns_vis_hhu_func", pybind11_ns_vis_hhu::func);                                          \
+    m.def("ns_vis_hhh_func", pybind11_ns_vis_hhh::func);

tests/test_constants_and_functions.cpp

@@ -10,6 +10,18 @@
 
 #include "pybind11_tests.h"
 
+// clang-format off
+namespace pybind11_ns_vis_uuu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uuh PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uhu PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_uhh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_huu PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_huh PYBIND11_NS_VIS_U { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_hhu PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+namespace pybind11_ns_vis_hhh PYBIND11_NS_VIS_H { PYBIND11_NS_VIS_FUNC }
+//                         ^
+// clang-format on
+
 enum MyEnum { EFirstEntry = 1, ESecondEntry };
 
 std::string test_function1() { return "test_function()"; }
@@ -83,6 +95,8 @@ struct C {
 } // namespace test_exc_sp
 
 TEST_SUBMODULE(constants_and_functions, m) {
+    PYBIND11_NS_VIS_DEFS
+
     // test_constants
     m.attr("some_constant") = py::int_(14);
 

tests/test_constants_and_functions.py

@@ -1,8 +1,37 @@
+import itertools
+
 import pytest
 
+import pybind11_cross_module_tests
+import pybind11_tests
+
 m = pytest.importorskip("pybind11_tests.constants_and_functions")
 
 
+def test_namespace_visibility():
+    mdls = (
+        pybind11_tests,
+        pybind11_tests.constants_and_functions,
+        pybind11_cross_module_tests,
+    )
+    codes = []
+    for vis in itertools.product(*([("u", "h")] * len(mdls))):
+        func = "ns_vis_" + "".join(vis) + "_func"
+        addrs = []
+        code = ""
+        for v, mdl in zip(vis, mdls):
+            addr = getattr(mdl, func)(True)
+            addrs.append(addr)
+            c = "ABC"[addrs.index(addr)]
+            if v == "h":
+                c = c.lower()
+            code += c
+        codes.append(code)
+    code_line = ":".join(codes)
+    if code_line != "AAC:AAc:AaC:Aac:aAC:aAc:aaC:aac":
+        pytest.skip(f"UNEXPECTED code_line: {code_line}")
+
+
 def test_constants():
     assert m.some_constant == 14
 

tools/pybind11NewTools.cmake

@@ -209,11 +209,11 @@ function(pybind11_add_module target_name)
   # namespace; also turning it on for a pybind module compilation here avoids
   # potential warnings or issues from having mixed hidden/non-hidden types.
   if(NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
-    set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
+    set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "default")
   endif()
 
   if(NOT DEFINED CMAKE_CUDA_VISIBILITY_PRESET)
-    set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
+    set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "default")
   endif()
 
   # If we don't pass a WITH_SOABI or WITHOUT_SOABI, use our own default handling of extensions

tools/pybind11Tools.cmake

@@ -189,11 +189,11 @@ function(pybind11_add_module target_name)
   # namespace; also turning it on for a pybind module compilation here avoids
   # potential warnings or issues from having mixed hidden/non-hidden types.
   if(NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
-    set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
+    set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "default")
   endif()
 
   if(NOT DEFINED CMAKE_CUDA_VISIBILITY_PRESET)
-    set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
+    set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "default")
   endif()
 
   if(ARG_NO_EXTRAS)