什么时候cmakes add_custom_command POST_BUILD被触发？

Question

让我们考虑一下我为目标注册了一个自定义命令：

add_custom_command(TARGET ${target_name} POST_BUILD
                   COMMAND cmake -E copy_if_different ${file_path} ${dest_file}
                   COMMENT "exporting ${file_path} to ${dest_file}"
                   VERBATIM)

我正在努力寻找的是命令实际运行的时间。 总是在像这样检查目标之后？

[ 10%] Built target libzmq

即使'没有必要做什么'？

或者只是为了目标必须要做的事情？

Answer 1

Documentation：

The command becomes part of the target and will only execute when the
target itself is built. If the target is already built, the command will
not execute.