Re: [hatari-devel] cmake: check_symbol_exists

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 11/02/2018 à 11:25, Troed Sångberg a écrit :
> Hi all,
>
> I must confess that I don't remember when I first noticed it, but it's a 
> long time now. Cmake didn't detect that I had the required libraries 
> (CapsImage, PortAudio etc) and I just patched the cmake files since they 
> obviously were there.
>
> I've now started to clean up the delta between what I have locally and 
> what's in mercurial, and part of that has been to investigate why cmake 
> module detection doesn't work here. It turns out that it's the use of 
> "check_function_exists" that simply never returns true, whatever changes 
> I make to the detection. Reading up on the cmake website it turns out 
> that they consider check_function_exists to be deprecated, there are 
> apparently many corner cases where it doesn't return the right values.
>
> The recommendation is: "Prefer using CheckSymbolExists instead of this 
> module"
>
> And that works for me. The attached patch replaces all usage of 
> check_function_exists with check_symbol_exists, and now all modules are 
> detected as they should on my build system. As an added bonus, all the 
> optional functions are now detected as well, which they weren't before. 
> (I'm not sure cfmakeraw is optional though, I had a workaround in 
> rs232.c because of its non-detection).
>
> If this seems sane and works as intended on other systems as well, this 
> patch brings down the delta between my build system and the repository 
> to only those specific changes I make to create universal release builds 
> (10.6+, fat libraries etc) that normal users would not need.

Hi

Thanks for the patch.
I tested it on 2 different linux systems and it worked fine, so I pushed 
this to main tree.

It didn't work correctly when crosscompiling for windows with mingw 
though, readline is not found ; I will look at this later, it should be 
fixable.


Nicolas