CMake 中 LINK_LIBRARIES 的递归列表 [英] Recursive list of LINK_LIBRARIES in CMake
问题描述
我正在尝试获取链接到 CMake 中特定目标的所有库的绝对路径列表，以用于调用 add_custom_command.但是，get_target_property(_LINK_LIBRARIES ${TARGET} LINK_LIBRARIES 仅包括直接依赖项(即在 target_link_libraries(${TARGET} ...) 调用中使用的任何内容).
I am trying to acquire a list of the absolute paths to all libraries linked to a specific target in CMake for use in a call to add_custom_command. However, get_target_property(_LINK_LIBRARIES ${TARGET} LINK_LIBRARIES only includes the direct dependencies (i.e. anything that is used in a target_link_libraries(${TARGET} ...) call).
因此，如果我链接另一个 CMake 目标，例如mylibrary，该列表将包括 mylibrary，但仅作为名称，不包含可传递链接的库.由于此列表还可以包含任意复杂的生成器表达式，因此检查每个项目是否为目标并递归检索其 LINK_LIBRARIES 是不可行的.此外，可以在稍后在 CMakeLists.txt 和 if(TARGET mylibrary) 中指定目标.
Therefore, if I link another CMake target, e.g. mylibrary, the list would include mylibrary, but as a name only and without transitively linked libraries. As this list can also include arbitrarily complex generator expressions, checking each item if it is a target and retrieving its LINK_LIBRARIES recursively is not viable. Furthermore the target could be specified at a later point in the CMakeLists.txt and if(TARGET mylibrary) would be skipped.
对于 INCLUDE_DIRECTORIES 和 COMPILE_DEFINITIONS，这很容易解决，尽管在使用 get_target_property 时两者的行为相似(除了链接目标显然不是在列表中)，形式为 $ 的生成器表达式生成所需的递归所需包含和定义列表.但是，$ 生成与 get_target_property 变体相同的列表.
For INCLUDE_DIRECTORIES and COMPILE_DEFINITIONS this is easily solved, as although both behave similarly when get_target_property is used (except that linked targets are obviously not in the list), a generator expression of the form $<TARGET_PROPERTY:${TARGET},INCLUDE_DIRECTORIES> produces the desired list of recursively required includes and definitions. However, $<TARGET_PROPERTY:${TARGET},LINK_LIBRARIES> produces the same list as the get_target_property variant.
如何检索所需的绝对路径列表?
How can I retrieve the desired list of absolute paths?
演示:
cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
file(WRITE a.cpp "void foo() {};
")
file(WRITE b.cpp "int main(int, char**) { return 0; }
")
find_package(Boost REQUIRED COMPONENTS filesystem system)
add_library(A STATIC a.cpp)
target_include_directories(A PUBLIC ${Boost_INCLUDE_DIRS})
target_link_libraries(A PUBLIC ${Boost_LIBRARIES})
# demonstrates (at configure time) that the LINK_LIBRARIES property can contain
# arbitrary generator expressions, making a recursive solution infeasible
get_target_property(A_LINK_LIBRARIES A LINK_LIBRARIES)
message(STATUS "A LINK_LIBARIES: ${A_LINK_LIBRARIES}")
add_executable(B b.cpp b_lists)
target_link_libraries(B PRIVATE A)
target_include_directories(B PRIVATE .)
get_target_property(B_INCLUDE_DIRECTORIES B INCLUDE_DIRECTORIES)
get_target_property(B_LINK_LIBRARIES B LINK_LIBRARIES)
# demonstrates (at compile time) that method 1 is not recursive while method 2 is (for INCLUDE_DIRECTORIES)
# demonstrates (at compile time) that the library list is never recursive
add_custom_command(
OUTPUT b_lists
COMMAND ${CMAKE_COMMAND} -E echo "B INCLUDE_DIRECTORIES 1: ${B_INCLUDE_DIRECTORIES}"
COMMAND ${CMAKE_COMMAND} -E echo "B INCLUDE_DIRECTORIES 2: $<TARGET_PROPERTY:B,INCLUDE_DIRECTORIES>"
COMMAND ${CMAKE_COMMAND} -E echo "B LINK_LIBRARIES 1: ${B_LINK_LIBRARIES}"
COMMAND ${CMAKE_COMMAND} -E echo "B LINK_LIBRARIES 2: $<TARGET_PROPERTY:B,LINK_LIBRARIES>"
DEPENDS A
)
set_source_files_properties(b_lists PROPERTIES SYMBOLIC TRUE)
输出:
(configure)
A LINK_LIBARIES: $<$<NOT:$<CONFIG:DEBUG>>:D:/libs/boost-1_55_0/lib/boost_filesystem-vc110-mt-1_55.lib>;$<$<CONFIG:DEBUG>:D:/libs/boost-1_55_0/lib/boost_filesystem-vc110-mt-gd-1_55.lib>;$<$<NOT:$<CONFIG:DEBUG>>:D:/libs/boost-1_55_0/lib/boost_system-vc110-mt-1_55.lib>;$<$<CONFIG:DEBUG>:D:/libs/boost-1_55_0/lib/boost_system-vc110-mt-gd-1_55.lib>
(build)
Generating b_lists
B INCLUDE_DIRECTORIES 1: D:/projects/cmakeminimal/.
B INCLUDE_DIRECTORIES 2: D:/projects/cmakeminimal/.;D:/libs/boost-1_55_0/include/boost-1_55
B LINK_LIBRARIES 1: A
B LINK_LIBRARIES 2: A
推荐答案
你的愿望已经存在一段时间了 - 据我所知 - 还没有(对于 CMake 3.3.2)嵌入到 中CMake 本身(请参阅 0012435:获取目标的所有链接库的可能性?).
Your wish has been out there for a while and is - as far as I know - not yet (as for CMake 3.3.2) embedded into CMake itself (see 0012435: Possibility to get all link libraries for a target?).
我得到了一些希望，因为这张票列出了一些可能的替代方法.但是在我针对您的示例 CMake 项目测试了这些之后，我会说它们并不是真正的解决方案:
I got some hope because this ticket lists a few possible alternative approaches. But after I tested those against your example CMake project I would say they are not really a solution:
注意:因为这仅适用于 Lib-To-Lib 依赖项，我有 - 对于此测试 - 将您的 add_executable() 更改为 add_library() 调用
Note: Because this works only for Lib-To-Lib dependencies I have - for this test - changed your add_executable() to an add_library() call
cmake_policy(SET CMP0033 OLD)
export_library_dependencies(LibToLibLinkDependencies.cmake)
include("${CMAKE_CURRENT_BINARY_DIR}/LibToLibLinkDependencies.cmake")
message("A_LIB_DEPENDS: ${A_LIB_DEPENDS}")
message("B_LIB_DEPENDS: ${B_LIB_DEPENDS}")
会给例如
A_LIB_DEPENDS: optimized;../libboost_filesystem-vc110-mt-1_53.lib;debug;../libboost_filesystem-vc110-mt-gd-1_53.lib;...
B_LIB_DEPENDS: general;A;
另见 policy CMP0033 export_library_dependencies() 命令不应该是称为
cmake_policy(SET CMP0024 OLD)
export(
TARGETS A B
FILE Test.cmake
NAMESPACE Imp_
)
include("${CMAKE_CURRENT_BINARY_DIR}/Test.cmake")
但这会将生成器表达式保留在输出中，您需要将所有依赖目标添加到列表中，所以不好.
But this keeps the generator expressions in the output and you need add to the list all depending targets, so no good.
我从 如何使用 cmake 函数 get_prerequisites 和 get_filename_component 进行目标依赖项安装?，但它显示 - 如模块文档中所述 - 它仅列出了共享库.
I've taken the code from how to use the cmake functions get_prerequisites and get_filename_component for target dependency installation?, but it shows - as described in the module's documentation - that it lists only the shared libraries.
add_custom_command(
OUTPUT b_lists
APPEND
COMMAND ${CMAKE_COMMAND} -D MY_BINARY_LOCATION="$<TARGET_FILE:B>" -P "${CMAKE_CURRENT_LIST_DIR}/ListSharedLibDependencies.cmake"
)
ListSharedLibDependencies.cmake
include(GetPrerequisites)
get_prerequisites(${MY_BINARY_LOCATION} DEPENDENCIES 0 0 "" "")
foreach(DEPENDENCY_FILE ${DEPENDENCIES})
gp_resolve_item("${MY_BINARY_LOCATION}" "${DEPENDENCY_FILE}" "" "" resolved_file)
message("resolved_file='${resolved_file}'")
endforeach()
会在我的 Windows 机器上输出:
would output on my Windows machine:
resolved_file='C:/Windows/SysWOW64/KERNEL32.dll'
resolved_file='C:/Windows/SysWOW64/MSVCR110D.dll'
参考资料
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