[cmake] Metabuild system script change suggestion

[Dalmurii]

removed library fetching on host UNIX -> target not UNIX.

		find_library(LIB_ATOMIC NAMES atomic)
		if(LIB_ATOMIC)
			list(APPEND COMMON_LINK_LIBRARIES ${LIB_ATOMIC})
		endif()

This part tries to fetch native library when targetted for MINGW, CGWIN, etc therefore linker panics. Funny.
I have bypassed them by simply not fetching libatomic under these conditions, under assumptions

separated build/install interface for smooth installation scenario.

target_include_directories(c89atomic PUBLIC  ${CMAKE_CURRENT_SOURCE_DIR})

source prefixed including will cause error on installing c89atomic.
separated include directories with build/install interface.

[mackron]

Thanks for this. I think this looks fine, but now all of my other libraries will have the same issues... That'll be fun.

So what's the issue with the target_include_directories() thing? Not doubting your PR or anything, I just don't do a whole lot with CMake so I'm a bit ignorant and I'd just like to properly understand exactly what it is I'm merging.

Out of curiosity, with the libatomic thing, are you using MinGW from a Linux host? And that actually produces Windows executables? I had always just assumed you needed to run MinGW from a Windows host.

[Dalmurii]

target_include_directories thing

When this library is to be installed as package (with install)
, since headers are to be fetched from somewhere else not from this codebase (the source)
, cmake will permit us no source-prefixed path to include when it's known as target.

That BUILD_INTERFACE INSTALL_INTERFACE thing is to separate the required path whether the process is building (you just want to compile & link) or installing (you want to ship your linked output to somewhere and one to use it).

MinGW libatomic thing

Yes it compiles something for Windows on Linux host. All you need to shift is some dll files simillar to vcruntime Microsoft requires us to install. Quite amazing.

I am using your project as a dependency of my personal open-source project.
My projects includes compiling tiny third-party tools I've written on configuring and running them on building.

I was checking if third-party tools are compiled for a host while I target another, like compiling mingw output on linux.

This is it if you do not mind: https://github.com/ae2f/Sys/

[Dalmurii]

Hello are you there