如何使用clang-10或gcc-10在建筑时通过吉突行动？

Question

我用C++编写了一个库，它实现了几个不同的coroutine原语，库的目标是新发布的C++20，因此，它还使用了C++20中添加到语言中的概念。

我想使用github操作来构建库，但是构建失败了，因为ubuntu-latest使用GCC 9和CLang 9，但是我的库至少需要GCC 10或Clang 10来构建。

我试图通过设置-DCMAKE_CXX_COMPILER=g++-10来配置构建操作，但是由于在系统上找不到g++-10，所以该操作在配置CMake阶段失败。

有没有办法指定github动作应该使用GCC 10或Clang 10?

这是我尝试运行的最新工作流文件：

name: CMake

on: [push]

env:
  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
  BUILD_TYPE: Release

jobs:
  build:
    # The CMake configure and build commands are platform agnostic and should work equally
    # well on Windows or Mac.  You can convert this to a matrix build if you need
    # cross-platform coverage.
    # See: https://docs.github.com/en/actions/configuring-and-managing-workflows/configuring-a-workflow#configuring-a-build-matrix
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    - name: Create Build Environment
      # Some projects don't allow in-source building, so create a separate build directory
      # We'll use this as our working directory for all subsequent commands
      run: cmake -E make_directory ${{runner.workspace}}/build

    - name: Configure CMake
      # Use a bash shell so we can use the same syntax for environment variable
      # access regardless of the host operating system
      shell: bash
      working-directory: ${{runner.workspace}}/build
      # Note the current convention is to use the -S and -B options here to specify source 
      # and build directories, but this is only available with CMake 3.13 and higher.  
      # The CMake binaries on the Github Actions machines are (as of this writing) 3.12
      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DCMAKE_CXX_COMPILER=g++-10

    - name: Build
      working-directory: ${{runner.workspace}}/build
      shell: bash
      # Execute the build.  You can specify a specific target with "--target <NAME>"
      run: cmake --build . --config $BUILD_TYPE

    - name: Test
      working-directory: ${{runner.workspace}}/build
      shell: bash
      # Execute tests defined by the CMake configuration.  
      # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
      run: ctest -C $BUILD_TYPE

这就是它失败的地方：

Run cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DCMAKE_CXX_COMPILER=g++-10
-- The CXX compiler identification is unknown
CMake Error at CMakeLists.txt:2 (project):
  The CMAKE_CXX_COMPILER:

    g++-10

  is not a full path and was not found in the PATH.

  Tell CMake where to find the compiler by setting either the environment
  variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
  to the compiler, or to the compiler name if it is in the PATH.


-- Configuring incomplete, errors occurred!
See also "/home/runner/work/conduit/build/CMakeFiles/CMakeOutput.log".
See also "/home/runner/work/conduit/build/CMakeFiles/CMakeError.log".
##[error]Process completed with exit code 1.

Answer 1

正如一些程序员所提到的，从apt安装g++是可行的方法(除非默认情况下是安装的)；在构建中增加一两分钟。然后，您可以通过在配置步骤中传递CC和CXX变量来告诉cmake它应该使用哪个编译器：

- run:   |
         sudo apt update
         sudo apt install gcc-10 g++-10
  shell: bash

# ... #

- run:   cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE
  shell: bash
  env:
   CC:   gcc-10
   CXX:  g++-10

当您想使用clang时，也会应用相同的解决方案。

Answer 2

我使用gcc-9和clang-10作为C(仅)项目.

- name: Setup dependencies
  if: startsWith(matrix.os, 'ubuntu')
  run: |
    sudo apt-get install -y gcc-9 llvm-10 clang-10
    sudo update-alternatives \
      --install /usr/bin/gcc gcc /usr/bin/gcc-9 100 \
      --slave /usr/bin/gcc-ar gcc-ar /usr/bin/gcc-ar-9 \
      --slave /usr/bin/gcc-ranlib gcc-ranlib /usr/bin/gcc-ranlib-9 \
      --slave /usr/bin/gcov gcov /usr/bin/gcov-9
    sudo update-alternatives \
      --install /usr/bin/llvm-ar llvm-ar /usr/bin/llvm-ar-10 100 \
      --slave /usr/bin/llvm-ranlib llvm-ranlib /usr/bin/llvm-ranlib-10 \
      --slave /usr/bin/llvm-cov llvm-cov /usr/bin/llvm-cov-10
    sudo update-alternatives \
      --install /usr/bin/clang clang /usr/bin/clang-10 100

你需要更新更多的C++项目的替代方案，举个例子。

Answer 3

通过访问https://github.com/actions/virtual-environments，您可以看到安装了什么。

如果您在2022年尝试，现在 ubuntu-latest有"GNU C++ 9.3.0，10.3.0“。g++链接到版本9，但是g++-10在路径上是可用的，无需任何额外的安装步骤。