fix: expose required symbol using clang (#5700)

* test: Added test case for visibility of common symbols across shared libraries

* style: pre-commit fixes

* tests: cmake target name fix

* tests: Added visibility test to ci

* tests: set the default visibility to hidden

* prototype/proof-of-concept fix: PYBIND11_EXPORT_GUARDED_DELETE

* Fix silly oversight: actually use PYBIND11_EXPORT_GUARDED_DELETE

* Update struct_smart_holder.h

* style: pre-commit fixes

* Update include/pybind11/detail/struct_smart_holder.h

* Update struct_smart_holder.h

* ci: fix addition to reusable-standard.yml

* Update CMakeLists.txt

* refactor: rename tests to test_cross_module_rtti

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>

.github/workflows/ci.yml

@@ -230,6 +230,9 @@ jobs:
     - name: Interface test
       run: cmake --build . --target test_cmake_build
 
+    - name: Visibility test
+      run: cmake --build . --target test_cross_module_rtti
+
 
   manylinux:
     name: Manylinux on 🐍 3.13t • GIL
@@ -328,6 +331,9 @@ jobs:
     - name: C++ tests
       run: cmake --build --preset default --target cpptest
 
+    - name: Visibility test
+      run: cmake --build --preset default --target test_cross_module_rtti
+
     - name: Run Valgrind on Python tests
       if: matrix.valgrind
       run: cmake --build --preset default --target memcheck
@@ -386,6 +392,8 @@ jobs:
     - name: Interface test
       run: cmake --build build --target test_cmake_build
 
+    - name: Visibility test
+      run: cmake --build build --target test_cross_module_rtti
 
   # Testing NVCC; forces sources to behave like .cu files
   cuda:
@@ -505,6 +513,8 @@ jobs:
     - name: Interface test
       run: cmake --build build --target test_cmake_build
 
+    - name: Visibility test
+      run: cmake --build build --target test_cross_module_rtti
 
   # Testing on GCC using the GCC docker images (only recent images supported)
   gcc:
@@ -556,6 +566,9 @@ jobs:
     - name: Interface test
       run: cmake --build build --target test_cmake_build
 
+    - name: Visibility test
+      run: cmake --build build --target test_cross_module_rtti
+
     - name: Configure - Exercise cmake -DPYBIND11_TEST_OVERRIDE
       if: matrix.gcc == '12'
       shell: bash
@@ -638,6 +651,11 @@ jobs:
         set +e; source /opt/intel/oneapi/setvars.sh; set -e
         cmake --build build-11 --target test_cmake_build
 
+    - name: Visibility test
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-11 --target test_cross_module_rtti
+
     - name: Configure C++17
       run: |
         set +e; source /opt/intel/oneapi/setvars.sh; set -e
@@ -670,6 +688,10 @@ jobs:
         set +e; source /opt/intel/oneapi/setvars.sh; set -e
         cmake --build build-17 --target test_cmake_build
 
+    - name: Visibility test
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-17 --target test_cross_module_rtti
 
   # Testing on CentOS (manylinux uses a centos base).
   centos:
@@ -732,6 +754,9 @@ jobs:
     - name: Interface test
       run: cmake --build build --target test_cmake_build
 
+    - name: Visibility test
+      run: cmake --build build --target test_cross_module_rtti
+
 
   # This tests an "install" with the CMake tools
   install-classic:
@@ -961,6 +986,9 @@ jobs:
     - name: Interface test C++20
       run: cmake --build build --target test_cmake_build
 
+    - name: Visibility test
+      run: cmake --build build --target test_cross_module_rtti
+
     - name: Configure C++20 - Exercise cmake -DPYBIND11_TEST_OVERRIDE
       run: >
         cmake -S . -B build_partial
@@ -1034,6 +1062,9 @@ jobs:
     - name: Interface test C++11
       run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target test_cmake_build
 
+    - name: Visibility test
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target test_cross_module_rtti
+
     - name: Clean directory
       run: git clean -fdx
 
@@ -1055,6 +1086,9 @@ jobs:
     - name: Interface test C++14
       run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target test_cmake_build
 
+    - name: Visibility test
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target test_cross_module_rtti
+
     - name: Clean directory
       run: git clean -fdx
 
@@ -1076,6 +1110,9 @@ jobs:
     - name: Interface test C++17
       run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target test_cmake_build
 
+    - name: Visibility test
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target test_cross_module_rtti
+
   windows_clang:
     if: github.event.pull_request.draft == false
 
@@ -1143,6 +1180,9 @@ jobs:
       - name: Interface test
         run: cmake --build . --target test_cmake_build -j 2
 
+      - name: Visibility test
+        run: cmake --build . --target test_cross_module_rtti -j 2
+
       - name: Clean directory
         run: git clean -fdx
 
@@ -1210,6 +1250,9 @@ jobs:
       - name: Interface test
         run: cmake --build . --target test_cmake_build -j 2
 
+      - name: Visibility test
+        run: cmake --build . --target test_cross_module_rtti -j 2
+
       - name: CMake Configure - Exercise cmake -DPYBIND11_TEST_OVERRIDE
         run: >
           cmake -S . -B build_partial