Pybind11 共享库可见性问题

Question

我们正在尝试将一些C ++代码编译到使用PYBIND11的共享库中。该共享库不调用Python函数，而是从Python脚本调用。然后，我们要创建一个使用此共享库来测试C ++代码的入门点C ++可执行文件。它不会以任何方式与Pybind或Python侧接口。

当我们这样做时，我们的共享库将成功编译。但是，在可执行的目标中，我们得到了各种链接器错误，指定“不确定的对”共享库中的构造函数。

阅读了PYBIND文档后，我们认为这是因为pybind11_add_module函数迫使cmake用“隐藏”的可见性标志编译共享库。随后，我们尝试在我们的C ++共享库中公开相关功能，以便我们的可执行文件可以访问它（使用__属性__（（visibility（vistibility（“ default”）））））。这解决了对我们的构造函数的未定义引用，但导致下面提供的错误。请注意，这些错误在编译我们的可执行文件时会发生。共享库仍然可以成功地编译。

[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyTuple_SetItem'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyObject_Repr'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyInstanceMethod_Type'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyExc_ValueError'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyLong_FromSsize_t'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyDict_GetItemString'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `_Py_TrueStruct'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyExc_IndexError'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyErr_NormalizeException'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyInstanceMethod_New'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyEval_AcquireThread'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyObject_Str'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyThreadState_DeleteCurrent'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyGILState_GetThisThreadState'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyObject_GetAttrString'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyCapsule_Type'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyModule_Type'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyMem_Free'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyErr_Restore'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyType_IsSubtype'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyModule_AddObject'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyErr_WarnEx'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyCapsule_SetPointer'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyTuple_New'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyObject_SetAttr'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyObject_IsInstance'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyEval_RestoreThread'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `_Py_NoneStruct'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyException_SetTraceback'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyUnicode_FromFormat'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyList_Append'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyExc_MemoryError'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyType_Type'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyDict_Next'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyList_Size'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyTuple_Size'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyBuffer_Release'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyErr_Format'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyObject_CallObject'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyFloat_FromDouble'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyUnicode_DecodeUTF8'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `_Py_Dealloc'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyCFunction_Type'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyExc_OverflowError'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyCFunction_NewEx'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyList_New'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyProperty_Type'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `_PyObject_GetDictPtr'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyUnicode_FromString'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `Py_GetVersion'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyCapsule_SetContext'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyFrame_GetLineNumber'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyThread_tss_get'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyBytes_Size'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PySequence_Check'
[build] ../pipeline_manager.cpython-38-x86_64-linux-gnu.so: undefined reference to `PyList_GetItem'
... [additional reference errors removed for brevity]
[build] collect2: error: ld returned 1 exit status

我们已经尝试了有关共享库汇编的可见性的各种命令，但始终出现上述一个或两个错误。在下面找到我们的cmakefiles：

主cmakelists.txt，该库编译共享库（带有与GSTREAMER，CUDA等无关的命令...为简短删除）：

cmake_minimum_required(VERSION 3.5)
project(visual_processing_node)

# Default to C99
if(NOT CMAKE_C_STANDARD)
  set(CMAKE_C_STANDARD 99)
endif()

# Default to C++14
if(NOT CMAKE_CXX_STANDARD)
  set(CMAKE_CXX_STANDARD 14)
endif()

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")

find_package(Threads REQUIRED)

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic)
endif()
    
# Fetch pybind11
include(FetchContent)
FetchContent_Declare(
    pybind11
    GIT_REPOSITORY https://github.com/pybind/pybind11.git
    GIT_TAG        v2.6.2
    GIT_SHALLOW    TRUE
)
FetchContent_MakeAvailable(pybind11)
pybind11_add_module(pipeline_manager SHARED src/deepstream_pipeline.cpp     src/deepstream_pipeline_helpers.cpp)

target_include_directories(
  pipeline_manager
  PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
         $<INSTALL_INTERFACE:include>
          ${GSTREAMER_INCLUDE_DIRS} ${GSTREAMER_APP_INCLUDE_DIRS}
          ${GLIB_INCLUDE_DIRS} ${GLOG_INCLUDE_DIRS} "${DeepStream_DIR}/lib")

target_link_libraries(
  pipeline_manager
  PUBLIC
  ${GSTREAMER_LIBRARIES}
  ${GLIB_LIBRARIES}
  ${GLIB_GIO_LIBRARIES}
  ${GLIB_GOBJECT_LIBRARIES}
  ${GLOG_LIBRARIES}
  ${GSTREAMER_APP_LIBRARIES}
  "/opt/nvidia/deepstream/deepstream-6.0/lib/libnvdsgst_meta.so"
  "/opt/nvidia/deepstream/deepstream-6.0/lib/libnvds_meta.so"
  gstrtspserver-1.0
  Threads::Threads)

add_subdirectory (tests)

第二个CMakelists.txt文件“测试”目录中的“测试”目录中可以编译可执行的。

add_executable (inferenceTest inference_test.cpp)
target_link_libraries (inferenceTest pipeline_manager
                        pybind11::module)
target_include_directories(inferenceTest PUBLIC
                       "${PROJECT_BINARY_DIR}")

Answer 1

我不确定是什么原因导致您遇到的错误，但是我可以建议解决方法，也许是一种更好的方法。

您可以构建两个共享库：一个包含您需要测试的C ++代码的库，以及动态链接到第一个，仅提供绑定定义的PYBIND11扩展名。

然后，您可以与第一个链接进行测试，而不会陷入困境。