CMAKE在共享库中使用git-submodule

Question

我尝试将库spdlog添加到dll（.so文件）中。 SPDLOG只是SPDLog库中的GIT子模块。查看文档，建议将其用作静态库。因此，我认为我试图在.so文件中编译它有一个问题。

为了清楚地了解我的工作，这是我的系统的照片：

我的root cmakelists.txt是：

cmake_minimum_required(VERSION 3.23)

# set the project name
project(Test VERSION "0.1.0" LANGUAGES CXX)

configure_file(config/config.h.in config.h)

# specify the C++ standard
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED True)
set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17 -O3")

# Set location for .so files
set(CMAKE_INSTALL_PREFIX "${CMAKE_BINARY_DIR}")

# Set location for executables
set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR}/bin)

add_subdirectory(Engine)
list(APPEND EXTRA_LIBS Engine)

add_subdirectory(Game)

target_link_libraries(Test PUBLIC ${EXTRA_LIBS})

target_include_directories(Test PUBLIC
                           "${PROJECT_BINARY_DIR}"
                           )

内部的发动机文件夹：

message(STATUS "BUILD Engine shared library File")

add_subdirectory(spdlog)
add_library(Engine SHARED Log.cpp Log.h)
target_include_directories(Engine
          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
          )

target_link_libraries(Engine
spdlog
)
target_include_directories(Engine
          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/spdlog/include
          )

内部游戏内部（我认为不相关），

message(STATUS "BUILD .exe File")
# add the executable
add_executable(Test main.cpp)

但是当前，如果我尝试在日志文件中使用SPDLOG，我会有此隐秘错误：

[build] /usr/bin/ld: spdlog/libspdlogd.a(spdlog.cpp.o): relocation R_X86_64_TPOFF32 against `_ZGVZN6spdlog7details2os9thread_idEvE3tid' can not be used when making a shared object; recompile with -fPIC

有人有想法吗？

Answer 1

多亏了Fabian在评论中，我

set(CMAKE_POSITION_INDEPENDENT_CODE 1)

刚刚添加SPDLog子目录之前添加了它，并且效果很好。