cmake - 将 compile_commands.json 复制到项目根文件夹

Question

我有一个 CMakeLists.txt在我的项目的根目录中 CMAKE_EXPORT_COMPILE_COMMANDS打开。

我正在文件夹中构建目标并通过 add_subdirectory 调用.该文件夹有自己的 CMakeLists.txt文件。
compile_commands.json建在二进制目录的根目录下，我想在运行cmake命令后将其复制到源目录的根目录。

我尝试了两种方法。

add_custom_target和 add_custom_command .
我创建了一个虚拟目标。我将此目标用于 add_custom_command复制文件，但它不会触发 add_custom_command 中的命令.

file(COPY ...)第一次触发命令时，compile_commands.json不是通过 cmake 创建的。我不想运行两次 cmake 命令来获取副本 compile_commands.json到源文件夹的根目录。

CMAKE_MINIMUM_REQUIRED(VERSION 3.8)
project(exec LANGUAGES CXX)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

add_subdirectory("DirectoyWithTarget")

add_custom_target(copy_compile_commands
  DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/compile_commands.json)
add_custom_command(
  TARGET copy_compile_commands
  PRE_BUILD
  COMMAND ${CMAKE_COMMAND} -E copy_if_different
    ${CMAKE_CURRENT_BINARY_DIR}/compile_commands.json
    ${CMAKE_CURRENT_SOURCE_DIR}/compile_commands.json
  )   

compile_commands.json文件未复制到 ${CMAKE_CURRENT_SOURCE_DIR} .这意味着 add_custom_command未触发。

Answer 1

还没有测试这么多，但这里有两个我想出的基于 cmake 的解决方案。

选项1

更少的代码，但总是运行。

add_custom_target(
    copy-compile-commands ALL
    ${CMAKE_COMMAND} -E copy_if_different
        ${CMAKE_BINARY_DIR}/compile_commands.json
        ${CMAKE_CURRENT_LIST_DIR}
    )

选项 2

更多代码，但会设置依赖项，因此除非需要，否则不会运行。可以处理在二进制目录中删除 compile_commands.json 的情况。

# Copy to source directory
add_custom_target(
    copy-compile-commands ALL
    DEPENDS
        ${CMAKE_CURRENT_LIST_DIR}/compile_commands.json
    )
add_custom_command(
    OUTPUT ${CMAKE_CURRENT_LIST_DIR}/compile_commands.json
    COMMAND ${CMAKE_COMMAND} -E copy_if_different
        ${CMAKE_BINARY_DIR}/compile_commands.json
        ${CMAKE_CURRENT_LIST_DIR}/compile_commands.json
    DEPENDS
        # Unlike "proper" targets like executables and libraries, 
        # custom command / target pairs will not set up source
        # file dependencies, so we need to list file explicitly here
        generate-compile-commands
        ${CMAKE_BINARY_DIR}/compile_commands.json
    )

# Generate the compilation commands. Necessary so cmake knows where it came
# from and if for some reason you delete it.
add_custom_target(generate-compile-commands
    DEPENDS
        ${CMAKE_BINARY_DIR}/compile_commands.json
    )
add_custom_command(
    OUTPUT ${CMAKE_BINARY_DIR}/compile_commands.json
    COMMAND ${CMAKE_COMMAND} -B${CMAKE_BINARY_DIR} -S${CMAKE_SOURCE_DIR}
    )