Improve cmake lto config #6333
Improve cmake lto config #6333
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| @@ -946,6 +946,10 @@ function _get_configs(package, configs, opt) | |||
| _get_configs_for_generic(package, configs, opt) | |||
| end | |||
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| if not opt._configs_str:find("CMAKE_INTERPROCEDURAL_OPTIMIZATION", 1, true) then | |||
| table.insert(configs, "-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=" .. (package:config("lto") and "ON" or "OFF")) | |||
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既然已经直接打 lto flags 进去了，为啥还要这个？跟现有打的 lto flags 冲突么？
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有些库会探测是否有这个选项，如果没有就开启 lto。比如 clang ci 链接还是用的 gnu ld，就链接失败了
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目前直接设置了 lto flags ，thin lto/full lto ，我不确定 CMAKE_INTERPROCEDURAL_OPTIMIZATION 用的是哪个，如果不一致，应该会有冲突问题。
不建议两个同时设置，如果设置了 CMAKE_INTERPROCEDURAL_OPTIMIZATION，那就不要再直接传递 lto flags
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那这个选项只传 off 就好了，lto flags 只让 xmake 传递。
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有些库会探测是否有这个选项，如果没有就开启 lto。比如 clang ci 链接还是用的 gnu ld，就链接失败了
只传 off 不就又有这个问题了么。
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- 直接硬编码
set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)的，只能手动 patch （msvc runtime 同理 - 有检测代码。只传 off 就是解决这种。
if(NOT DEFINED CMAKE_INTERPROCEDURAL_OPTIMIZATION)
set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
endif()
| @@ -946,6 +946,10 @@ function _get_configs(package, configs, opt) | |||
| _get_configs_for_generic(package, configs, opt) | |||
| end | |||
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| if not opt._configs_str:find("CMAKE_INTERPROCEDURAL_OPTIMIZATION", 1, true) then | |||
| table.insert(configs, "-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=OFF") | |||
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这怎么看着有点 hack， 依赖特定包中对 CMAKE_INTERPROCEDURAL_OPTIMIZATION defined 的判断。
确定所有包和 cmake 内部都是defined 这种形式来判断？永远不会出现 if(NOT CMAKE_INTERPROCEDURAL_OPTIMIZATION)?
if(NOT DEFINED CMAKE_INTERPROCEDURAL_OPTIMIZATION)
set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
endif()
在没这个上下文背景下，单看这个 patch ，字面上跟 lto flags 设置状态，很不搭。
要么开头加点注释详细说明下情况，否则我怕 过上一阵子，就看不懂了
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