调用set_target_properties的参数数量不正确？

Question

这是我的简单CMakeLists.txt文件：

include_directories (${CMAKE_SOURCE_DIR}/common)
find_package(Threads)

add_library (libusbmuxd SHARED libusbmuxd.c sock_stuff.c ${CMAKE_SOURCE_DIR}/common/utils.c)
find_library (PTHREAD pthread)
target_link_libraries (libusbmuxd ${CMAKE_THREAD_LIBS_INIT})

# 'lib' is a UNIXism, the proper CMake target is usbmuxd
# But we can't use that due to the conflict with the usbmuxd daemon,
# so instead change the library output base name to usbmuxd here
set_target_properties(libusbmuxd PROPERTIES OUTPUT_NAME usbmuxd)
set_target_properties(libusbmuxd PROPERTIES VERSION ${LIBUSBMUXD_VERSION})
set_target_properties(libusbmuxd PROPERTIES SOVERSION ${LIBUSBMUXD_SOVERSION})

install(TARGETS libusbmuxd
    ARCHIVE DESTINATION lib${LIB_SUFFIX}
    LIBRARY DESTINATION lib${LIB_SUFFIX}
)
install(FILES usbmuxd.h usbmuxd-proto.h DESTINATION include)

这给了我一个错误：
CMake error at CMakeLists.txt:12 (set_target_properties):
set_target_properties called with incorrect number of arguments

CMake error at CMakeLists.txt:13 (set_target_properties):
set_target_properties called with incorrect number of arguments 这些是第二个和第三个set_target_properties。第一个set_target_properties从来没有遇到过这个问题？ （如果你还没有意识到，我正在尝试构建usbmuxd-1.0.4）

Answer 1

SET_TARGET_PROPERTIES的格式为：

SET_TARGET_PROPERTIES(
    target1 target2 ... targetM
    PROPERTIES 
    prop1 val1 prop2 val2 ... propN valN
)

您遇到问题的原因是您的变量LIBUSBMUXD_VERSION和LIBUSBMUXD_SOVERSION未定义，因此您的命令语法为：

SET_TARGET_PROPERTIES(target PROPERTIES name)

而不是：

SET_TARGET_PROPERTIES(target PROPERTIES name value)

要解决此问题，请尝试引用变量;使用“$ {LIBUSBMUXD_SOVERSION}”应确保即使变量未定义，它也会采用空字符串的值，从而遵守语法。