【发布时间】：2018-09-25 06:24:55
【问题描述】：
我对 CMake 在 Windows 机器上处理库链接的方式有点困惑。下面我有一个简单的CMakeLists.txt 文件：
cmake_minimum_required (VERSION 3.10)
project (sample)
add_library (quad SHARED quad.cpp)
add_executable (run main.cpp)
target_link_libraries (run PRIVATE quad)
在 Linux/Mac 机器上，CMake 正确构建 *.so/*.dylib 库并将可执行文件链接到 *.so/*.dylib 文件。但是在 Windows 机器上，它会构建 *.dll 文件，然后尝试链接 *.lib 文件。
CMake 在底层执行以下命令：
>------ Build started: Project: CMakeLists, Configuration: Debug ------
[1/4] C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1415~1.267\bin\HostX64\x64\cl.exe /nologo /TP -Dquad_EXPORTS /DWIN32 /D_WINDOWS /W3 /GR /EHsc /MDd /Zi /Ob0 /Od /RTC1 /showIncludes /FoCMakeFiles\quad.dir\quad.cpp.obj /FdCMakeFiles\quad.dir\ /FS -c C:\Users\UX\Workspace\sample\quad.cpp
[2/4] C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1415~1.267\bin\HostX64\x64\cl.exe /nologo /TP /DWIN32 /D_WINDOWS /W3 /GR /EHsc /MDd /Zi /Ob0 /Od /RTC1 /showIncludes /FoCMakeFiles\run.dir\main.cpp.obj /FdCMakeFiles\run.dir\ /FS -c C:\Users\UX\Workspace\sample\main.cpp
[3/4] cmd.exe /C "cd . && "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_dll --intdir=CMakeFiles\quad.dir --manifests -- C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1415~1.267\bin\Hostx64\x64\link.exe /nologo CMakeFiles\quad.dir\quad.cpp.obj /out:quad.dll /implib:quad.lib /pdb:quad.pdb /dll /version:0.0 /machine:x64 /debug /INCREMENTAL kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ."
[4/4] cmd.exe /C "cd . && "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_exe --intdir=CMakeFiles\run.dir --manifests -- C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1415~1.267\bin\Hostx64\x64\link.exe /nologo CMakeFiles\run.dir\main.cpp.obj /out:run.exe /implib:run.lib /pdb:run.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console quad.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ."
FAILED: run.exe
cmd.exe /C "cd . && "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_exe --intdir=CMakeFiles\run.dir --manifests -- C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1415~1.267\bin\Hostx64\x64\link.exe /nologo CMakeFiles\run.dir\main.cpp.obj /out:run.exe /implib:run.lib /pdb:run.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console quad.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ."
LINK Pass 1: command "C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1415~1.267\bin\Hostx64\x64\link.exe /nologo CMakeFiles\run.dir\main.cpp.obj /out:run.exe /implib:run.lib /pdb:run.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console quad.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTFILE:CMakeFiles\run.dir/intermediate.manifest CMakeFiles\run.dir/manifest.res" failed (exit code 1104) with the following output:
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\LINK : fatal error LNK1104: cannot open file 'quad.lib'
ninja: build stopped: subcommand failed.
Build failed.
我的问题是，当 CMake 文档说明以下内容时，为什么它会在 Windows 上失败：
target_link_libraries(<target>
<PRIVATE|PUBLIC|INTERFACE> <item>...
[<PRIVATE|PUBLIC|INTERFACE> <item>...]...)
item 在哪里可以是A library target name？它不应该从target 的属性中获得足够的信息来识别编译库的完整路径及其类型（即SHARED）以便能够正确链接可执行文件吗？
【问题讨论】：