问题描述
我正在尝试在我的项目中使用 zlib。 CMakeLists.txt 如下:
cmake_minimum_required(VERSION 3.5)
project(cmake-demo LANGUAGES CXX)
# The version number.
set(CMDemo_VERSION_MAJOR 0)
set(CMDemo_VERSION_MInor 1)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_required ON)
include(${PROJECT_SOURCE_DIR}/build/conan_paths.cmake)
set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/build)
find_package(uwebsockets)
#ZLIB
if(ZLIB_FOUND)
set(INC_Dirs ${INC_Dirs} ${ZLIB_INCLUDE_Dirs})
set(LINK_LIBS ${LINK_LIBS} ${ZLIB_LIBS})
endif()
# Global approach
if(uwebsockets_FOUND)
set(INC_Dirs ${INC_Dirs} ${uwebsockets_INCLUDE_Dirs})
set(LINK_LIBS ${LINK_LIBS} ${uwebsockets_LIBS})
endif()
#libuv
if(libuv_FOUND)
set(INC_Dirs ${INC_Dirs} ${libuv_INCLUDE_Dirs})
set(LINK_LIBS ${LINK_LIBS} ${libuv_LIBS})
endif()
#usockets
if(usockets_FOUND)
set(INC_Dirs ${INC_Dirs} ${usockets_INCLUDE_Dirs})
set(LINK_LIBS ${LINK_LIBS} ${usockets_LIBS})
endif()
include_directories(${INC_Dirs})
add_executable(${PROJECT_NAME} main.cpp)
message("libs=${LINK_LIBS}")
target_link_libraries(${PROJECT_NAME} ${LINK_LIBS})
#output of message("${LINK_LIBS}")
C:/ProgramData/Miniconda3/Library/lib/z.lib;C:/Users/Sunway/.conan/data/libuv/1.41.0/_/_/package/9965605309592d7e617ec929633249a2031e4263/lib/libuv_a.a;C:/Users/Sunway/.conan/data/usockets/0.7.1/_/_/package/a24f5291464b4270092bce2e738cbf9f3cd53bb7/lib/libuSockets.a
我确定 ${LINK_LIBS} 是正确的,但它仍然不起作用:
CMakeFiles/cmake-demo.dir/main.cpp.obj: In function `ZN3uWS15DeflationStreamD1Ev':
C:/Users/Sunway/.conan/data/uwebsockets/19.2.0/_/_/package/5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9/include/uWebSockets/PerMessageDeflate.h:186: undefined reference to `deflateEnd'
操作系统:Windows10 x64
IDE:QtCreator4.14.2
编译器:MinGW 32 位
解决方法
问题是,您必须将库文件的路径设置为 target_link_libraries
参数。
根据documentation,如果要链接库,target_link_libraries
的每个参数可以是:
- 库目标名称
- 库文件的完整路径(例如
/usr/lib/foo.so
) - 简单的库名称(例如
foo
)
在您的情况下,我建议您添加库的完整路径。
我没有你项目的所有代码,所以我建议你考虑这个最小的例子:
add_executable(test main.cpp)
SET (ZLIB_ROOT "/tmp/zlib")
SET (ZLIB_INCLUDE_DIR "/tmp/zlib/include/")
SET (ZLIB_LIBRARY "/tmp/zlib/lib/libz.so.1.2.11")
FIND_PACKAGE (ZLIB REQUIRED)
MESSAGE (" zlib version major is " ${ZLIB_VERSION_MAJOR})
MESSAGE (" zlib version minor is " ${ZLIB_VERSION_MINOR})
MESSAGE (" zlib include is " ${ZLIB_INCLUDE_DIR})
MESSAGE (" zlib libraries are " ${ZLIB_LIBRARIES})
target_link_libraries(test ${ZLIB_LIBRARIES})
下载 latest zlib release 并将其安装在 /tmp
后,一切正常。
更新:正如 @uilianries 所提到的,由于您使用的是 conan,因此您拥有 cmake_find_package 生成器,它定义了具有所有必要路径的变量。因此您无需手动设置 CMakeLists.txt
中的路径。
这是因为libzlib.a是针对x86_64的,而编译器是MinGW-32bit;我通过执行命令解决了问题
$conan install .. --build=missing --pr=x86_32
x86_64 是由 conan 生成的配置文件(x86)。