Question

受到this的启发，我试图创建一个macro，它会在构建时复制文件列表。

macro   (copy_files_at_build_time targetname) #usage: copy_files_at_build_time(<targetname> <file> [<files>] <destination>)
    if(ARGC LESS 3)
        message(ERROR "copy_files_at_build_time called with less than 3 arguments")
    endif(ARGC LESS 3)
    MATH(EXPR LAST_INDEX "${ARGC}-2")
    MATH(EXPR DEST_INDEX "${ARGC}-1")
    set(MY_DESTINATION ${ARGV${DEST_INDEX}})
    foreach(I RANGE 1 ${LAST_INDEX})
        message (STATUS "${CMAKE_COMMAND} -E copy ${ARGV${I}} ${MY_DESTINATION}")
        add_custom_command(TARGET ${targetname} PRE_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different ${ARGV${I}} ${MY_DESTINATION})
    endforeach(I)
endmacro(copy_files_at_build_time)

正如您所看到的那样，有一条调试消息，不幸的是，当我打印它们时，${ARGV${I}}和${MY_DESTINATION}（${ARGV${DEST_INDEX}}）都是空的。因此，似乎无法通过使用变量作为变量名的最后一部分来访问ARGV1，ARGV2等（请参阅macro documentation）。我现在将使用list命令实现一种解决方法，但我的问题是：

如果必须跳过某些元素（例如第一个和最后一个元素），是否有更简单的方法在ARGV0，ARGV1，ARGV2元素上循环？

修改

可悲的是，我发现即使是LIST命令也无法在ARGV上运行！但是如果我首先创建一个ARGV副本然后在其上执行LIST命令，它们就可以工作。

Answer 1

MACROS不支持

${ARGV${DEST_INDEX}})（至少根据我的经验）。您必须使用LIST(...)参数列表执行${ARGV}操作来处理MACRO参数。

使用：

LIST(REMOVE_AT, ...)或类似的列表操作，用于删除参数或
使用FOREACH(loop_var IN ...)

Answer 2

这是我最终的实施，我愿意接受更好的解决方案！注意：如果某些目标目录不存在，第二个函数（也复制目录的那个）可能更安全。

macro   (copy_files_at_build_time targetname) #usage: copy_files_at_build_time(<targetname> <file> [<files>] <destination>)
    if(ARGC LESS 3)
        message(ERROR "copy_files_at_build_time called with less than 3 arguments")
    endif(ARGC LESS 3)
    SET(ARGN_COPY ${ARGN})
    MATH(EXPR DEST_INDEX "${ARGC}-2") #It should be "${ARGC}-1", but we are using ARGN that doesn't contain the first element of the list
    list(GET ARGN_COPY ${DEST_INDEX} MY_DESTINATION)
    list(REMOVE_AT ARGN_COPY ${DEST_INDEX})
    foreach(MY_FILE ${ARGN_COPY})
#       message (STATUS "${CMAKE_COMMAND} -E copy_if_different ${MY_FILE} ${MY_DESTINATION}")
        add_custom_command(TARGET ${targetname} PRE_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different ${MY_FILE} ${MY_DESTINATION})
    endforeach(MY_FILE)
endmacro(copy_files_at_build_time)

如果我们想复制目录（注意：如果递归工作则不测试！）

macro   (copy_at_build_time targetname) #usage: copy_at_build_time(<targetname> <file|directory> [<files|directories>] <destination>)
    if(ARGC LESS 3)
        message(ERROR "copy_files_at_build_time called with less than 3 arguments")
    endif(ARGC LESS 3)
    SET(ARGN_COPY ${ARGN})
    MATH(EXPR DEST_INDEX "${ARGC}-2") #It should be "${ARGC}-1", but we are using ARGN that doesn't contain the first element of the list
    list(GET ARGN_COPY ${DEST_INDEX} MY_DESTINATION)
    list(REMOVE_AT ARGN_COPY ${DEST_INDEX})
    foreach(MY_FILE ${ARGN_COPY})
        get_filename_component(LEAF_NAME "${MY_FILE}" NAME)
        if (IS_DIRECTORY ${MY_FILE})
            add_custom_command(TARGET ${targetname} PRE_BUILD COMMAND ${CMAKE_COMMAND} -E copy_directory ${MY_FILE} ${MY_DESTINATION}/${LEAF_NAME})
        else(IS_DIRECTORY ${MY_FILE})
            add_custom_command(TARGET ${targetname} PRE_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different ${MY_FILE} ${MY_DESTINATION}/${LEAF_NAME})
        endif(IS_DIRECTORY ${MY_FILE})
    endforeach(MY_FILE)
endmacro(copy_at_build_time)

在cmake中循环部分宏的参数

2 个答案: