[CMake] Does find_library check that a found library does in fact link?

[Hendrik Sattler]

Zitat von Michael Wild <themiwi at gmail.com>:
> Just a few of my thoughts on this:

Same for me.

> - There are several ways to handle dead symlinks:
>   1. Don't check, let the linker complain (status quo)
>   2. Check whether the found library is a symlink, and if not valid,
>      remove it silently from the list of candidates. Can be very
>      surprising and will likely result in quite a few bug reports
>      about CMake not finding a certain library that is "clearly" there.
>   3. Like 2, but warn about the issue. Possibly very annoying.
> I don't know which option to prefer (perhaps somebody finds another one
> that is better?). IMHO bogus symlinks to shared libraries constitute a
> real problem of the library installation, so CMake shouldn't just paper
> over it by silently skipping the dead link, proceeding to the next
> candidate which rules out option 2 for me. Also, option 3 can be
> troublesome in automated setups where no user actually reads the CMake
> output.

People tend to misunderstand the purpose of build systems like CMake  
and autotools. They try to make the detection bullet-proof and most  
likely fail. You can see that this is wrong by looking at those auto*  
setups that take ages to detect all possible header files and use an  
ifdef hell to handle that in the code, run lots of link and  
symbol-finding tests, and still fail on conditions that the author  
simple didn't consider or know.

I prefer option 1. It's not CMake's duty to detect or paper over  
messed-up systems. That's the administrator's job!
BTW: running "ldconfig -v" on Linux likely tells you about the  
dangling symlink.

What's next? Asking for a syntax check of found header files so that  
the compiler doesn't complain on broken header files?

HS