如何在VS2019 CMAKE中使用Clang-CL LLVM？

如何解决如何在VS2019 CMAKE中使用Clang-CL LLVM？

在撰写本文时，clang的Visual Studio用户手册中包含以下文档：

cmake -G"Visual Studio 2017" -T LLVM ..

这不起作用。

我从cmake收到一条错误消息：

CMake Error at CMakeLists.txt:3 (project):
  Failed to run MSBuild command:

    C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/MSBuild/Current/Bin/MSBuild.exe

  to get the value of VCTargetsPath:

    Microsoft (R) Build Engine version 16.7.0+b89cb5fde for .NET Framework
    copyright (C) Microsoft Corporation. All rights reserved.

    Build started 10/3/2020 5:06:06 PM.
    Project "D:\Github\glfw\build\CMakeFiles\3.18.1\VCTargetsPath.vcxproj" on node 1 (default targets).
    C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets(411,5): error MSB8020: The build tools for LLVM99 (Platform Toolset = 'LLVM99') cannot be found. To build using the LLVM99 build tools,please install LLVM99 build tools.  Alternatively,you may upgrade to the current Visual Studio tools by selecting the Project menu or right-click the solution,and then selecting "Retarget solution". [D:\Github\glfw\build\CMakeFiles\3.18.1\VCTargetsPath.vcxproj]
    Done Building Project "D:\Github\glfw\build\CMakeFiles\3.18.1\VCTargetsPath.vcxproj" (default targets) -- Failed.

    Build Failed.

    "D:\Github\glfw\build\CMakeFiles\3.18.1\VCTargetsPath.vcxproj" (default target) (1) ->
    (PrepareForBuild target) ->
on,and then selecting "Retarget solution". [D:\Github\glfw\build\CMakeFiles\3.18.1\VCTargetsPath.vcxproj]

        0 Warning(s)
        1 Error(s)

    Time Elapsed 00:00:00.11


  Exit code: 1



-- Configuring incomplete,errors occurred!
See also "D:/Github/glfw/build/CMakeFiles/CMakeOutput.log".

解决方法

这不适用于VS2019。在vs2019中，您必须将工具集指定为 ClangCL 。 据我所知，该更改未记录在任何地方。 我只能通过反复试验找出答案。

cmake -G"Visual Studio 2019" -T ClangCL ..

这是您将获得的输出。

PS D:\Github\glfw> cmake -S . -B build -T ClangCl
-- Building for: Visual Studio 16 2019
-- Selecting Windows SDK version 10.0.18362.0 to target Windows 10.0.19041.
-- The C compiler identification is Clang 10.0.0 with MSVC-like command-line
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/x64/bin/clang-cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Looking for pthread.h
-- Looking for pthread.h - not found
-- Found Threads: TRUE  
-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
-- Using Win32 for window creation
-- Configuring done
-- Generating done
-- Build files have been written to: D:/Github/glfw/build

这是它的样子：

,

如https://cmake.org/cmake/help/v3.18/manual/cmake.1.html

中所述

-T <toolset-spec>

    Toolset specification for the generator,if supported.

Visual 2017不支持Clang / LLVM：
https://docs.microsoft.com/cpp/build/clang-support-msbuild?view=vs-2017

对于Visual Studio 2019，您需要使用clang-cl。 https://docs.microsoft.com/cpp/build/clang-support-msbuild?view=vs-2019。

如果要查看受支持的生成器：
https://cmake.org/cmake/help/v3.18/manual/cmake-generators.7.html