More flexible package fetching from cmake

[xq114]

你在什么场景下需要该功能？

https://cmake.org/cmake/help/latest/guide/using-dependencies/index.html#guide:Using%20Dependencies%20Guide

希望xmake支持：

• Module/Config模式设置 find_package(ABC CONFIG REQUIRED) (仅从ABCConfig.cmake查找)
• Components设置 find_package(Boost 1.79 COMPONENTS date_time)
• 特定target设置 target_link_libraries(test PRIVATE ABC::lib1 ABC::lib3)

这里第3点很重要，因为package提供的cflags、cxxflags、defines、syslinks都是通过这种方式链接才有，只链接ABC_LIBRARIES不仅无法控制链接的库和顺序（可能导致冲突），还会丢失信息（可能导致编译不过）。

描述可能的解决方案

改进cmake/find_package模块

描述你认为的候选方案

No response

其他信息

No response

[waruqi]

Components设置 find_package(Boost 1.79 COMPONENTS date_time)

这个不是原本就支持么

xmake/xmake/modules/package/manager/cmake/find_package.lua

Lines 42 to 55 in 30ceace

	-- e.g. OpenCV 4.1.1, Boost COMPONENTS regex system
	local requirestr = name
	local configs = opt.configs or {}
	if opt.require_version and opt.require_version ~= "latest" then
	requirestr = requirestr .. " " .. opt.require_version
	end
	-- use opt.components is for backward compatibility
	local components = configs.components or opt.components
	if components then
	requirestr = requirestr .. " COMPONENTS"
	for _, component in ipairs(components) do
	requirestr = requirestr .. " " .. component
	end
	end

[waruqi]

特定target设置 target_link_libraries(test PRIVATE ABC::lib1 ABC::lib3)

这个怎么搞？要么传自定义 targetlinks 进去，add_requires("cmake::xxx", {configs = {targetlinks = {"abc::lib1", "abc::lib2"}}})

[waruqi]

Module/Config模式设置 find_package(ABC CONFIG REQUIRED) (仅从ABCConfig.cmake查找)

还有这，add_requires("cmake::xxx", {configs = {find_config = true}}) 这样？

要么你直接来个 pr 吧。https://github.com/xmake-io/xmake/blob/master/xmake/modules/package/manager/cmake/find_package.lua

[xq114]

特定target设置 target_link_libraries(test PRIVATE ABC::lib1 ABC::lib3)

这个怎么搞？要么传自定义 targetlinks 进去，add_requires("cmake::xxx", {configs = {targetlinks = {"abc::lib1", "abc::lib2"}}})

targetlinks这个名字不是很贴切，改成link_libraries比较好，因为cmake里面的target_link_libraries(test PRIVATE ABC::lib1 ABC::lib3)是把 test 这个 target ”link“ 到 libraries ABC::lib1 和 ABC::lib3。{find_config = true}也不如{search_mode = "config"}好，后者可以设置"both" "config" "module"。见 https://cmake.org/cmake/help/latest/command/find_package.html#id4

[waruqi]

好了

add_requires("cmake::xxx", {configs = {link_libraries = {"abc::lib1", "abc::lib2"}}})
add_requires("cmake::xxx", {configs = {search_mode = "config"}}) -- module, both

[xq114]

不好意思我没讲清楚，both就是啥也不加，默认就两个都找，不需要额外声明，需要声明的只有config和module

[waruqi]

好了

add_requires("cmake::xxx", {configs = {link_libraries = {"abc::lib1", "abc::lib2"}}})
add_requires("cmake::xxx", {configs = {search_mode = "config"}}) -- module, both

那就不设置就行了

add_requires("cmake::xxx", {configs = {search_mode = "config"}})
add_requires("cmake::xxx", {configs = {search_mode = "module"}})
add_requires("cmake::xxx") -- both