Compile with hidden visibility always; set via cmake property rather than compiler flag
This updates the compilation to always apply hidden visibility to
resolve the issues with default visibility causing problems under debug
compilations. Moreover using the cmake property makes it easier for a
caller to override if absolutely needed for some reason.
For `pybind11_add_module` we use cmake to set the property; for the
targets, we append to compilation option to non-MSVC compilers.
diff --git a/tools/pybind11Tools.cmake b/tools/pybind11Tools.cmake
index 86ccd58..63752ea 100644
--- a/tools/pybind11Tools.cmake
+++ b/tools/pybind11Tools.cmake
@@ -139,6 +139,13 @@
set_target_properties(${target_name} PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX}")
set_target_properties(${target_name} PROPERTIES SUFFIX "${PYTHON_MODULE_EXTENSION}")
+ # -fvisibility=hidden is required to allow multiple modules compiled against
+ # different pybind versions to work properly, and for some features (e.g.
+ # py::module_local). We force it on everything inside the `pybind11`
+ # namespace; also turning it on for a pybind module compilation here avoids
+ # potential warnings or issues from having mixed hidden/non-hidden types.
+ set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
+
if(WIN32 OR CYGWIN)
# Link against the Python shared library on Windows
target_link_libraries(${target_name} PRIVATE ${PYTHON_LIBRARIES})
@@ -175,9 +182,6 @@
_pybind11_add_lto_flags(${target_name} ${ARG_THIN_LTO})
if (NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug)
- # Set the default symbol visibility to hidden (very important to obtain small binaries)
- target_compile_options(${target_name} PRIVATE "-fvisibility=hidden")
-
# Strip unnecessary sections of the binary on Linux/Mac OS
if(CMAKE_STRIP)
if(APPLE)