如何使用 CMake 一次性创建静态和共享库？

Question

In my project, static library is created using cmake. But now i wanted to change it to create and support both static and shared libraries.

Could someone please help me how to proceed with that?

Below is my existing script for the static library:

include(bundle_static_library.cmake)

set(BINARY camsdk)

set(CMAKE_VERBOSE_MAKEFILE ON)

include_directories("../../OpenSource/boost_1_75_0")
if(CMAKE_HOST_WIN32)
add_definitions(-DBOOST_DATE_TIME_NO_LIB)
endif()
include_directories(Include)
include_directories("../Dependencies/CamSupport/h")

file(GLOB_RECURSE SOURCES LIST_DIRECTORIES true *.h *.cpp)
set(SOURCES 
    ${SOURCES}
    ${CMAKE_CURRENT_LIST_DIR}/../CamVisionLibrary/Source/VisionClient.cpp)

if(CMAKE_HOST_UNIX)
    add_compile_options(-fpic -Wall -Werror)
    add_definitions(-DBOOST_UUID_RANDOM_PROVIDER_FORCE_POSIX)
elseif(CMAKE_HOST_WIN32)
    # all warnings as errors
    add_compile_options(/W4 /WX)
    add_definitions(-D_UNICODE -DUNICODE)
endif ()

if(${CMAKE_BUILD_TYPE} STREQUAL "Debug")
    set(BUILD_TYPE "debug")
else()
    set(BUILD_TYPE "release")
endif() 

if(${CMAKE_SYSTEM_NAME} STREQUAL "Darwin")
    set(PLATFORM "macos")
elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
    set(PLATFORM "windows")
else()
    set(PLATFORM "linux")
endif()

# We depend on another static library EMR
add_library(EMR STATIC IMPORTED)
if(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
    if(NOT CMAKE_CL_64)
        message(STATUS "Architecture: x86")
        set_property(TARGET EMR PROPERTY IMPORTED_LOCATION ${CMAKE_SOURCE_DIR}/Library/emr/lib/${PLATFORM}-x86-${BUILD_TYPE}-static/testemr-cc.lib)
    else()
        message(STATUS "Architecture: x64")
        set_property(TARGET EMR PROPERTY IMPORTED_LOCATION ${CMAKE_SOURCE_DIR}/Library/emr/lib/${PLATFORM}-x64-${BUILD_TYPE}-static/testemr-cc.lib)
    endif()
else()
    set_property(TARGET EMR PROPERTY IMPORTED_LOCATION ${CMAKE_SOURCE_DIR}/Library/emr/lib/${PLATFORM}-x64-${BUILD_TYPE}-static/libtestemr-cc.a)
endif()

# First build a temporary library
set(TMP_BINARY camsdk-tmp)
add_library(${TMP_BINARY} STATIC ${SOURCES})
target_link_libraries(${TMP_BINARY} PUBLIC EMR)

bundle_static_library(${TMP_BINARY} ${BINARY})

Answer 1

As I recall, the best way to handle this is with CMake Object libraries. An object library contains the compiled objects, which you can then wrap with shared and static versions. This avoids the need to compile twice. For example:

add_library(something OBJECT lib/something.cpp)
target_include_directories(something PUBLIC lib)

add_library(something_shared SHARED)
target_link_libraries(something_shared PUBLIC something)

add_library(something_static STATIC)
target_link_libraries(something_static PUBLIC something)

In this example, you compile the .cpp once, then you wrap that library with a shared and static version that you can link to.