Re: [Qemu-devel] [PATCH] configure: Detect when glibc implements makecontext() to always fail

[Andreas Färber]

Am 13.10.2011 16:26, schrieb Andreas Färber:
> Am 12.10.2011 18:21, schrieb Peter Maydell:
>> Improve the configure test for presence of ucontext functions by
>> making linker warnings fatal; this allows us to detect when we are
>> linked with a glibc which implements makecontext() to always return
>> ENOSYS.
>>
>> Signed-off-by: Peter Maydell<address@hidden>
> 
> Tested-by: Andreas Färber <address@hidden>
> 
>> ---
>> Compiling on an Ubuntu Natty ARM host will hit this.
> 
> Works on Ubuntu Maverick ARM host as well.

Erm... This works great, also for accept4(), on Linux, but it's not
portable. Apple ld(1) doesn't seem to have --fatal-warnings.

http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/Xcode-3.2.5/man1/ld.1.html

Sun/Oracle ld(1) does seem to have it as alias to -z fatal-warnings.

http://download.oracle.com/docs/cd/E19963-01/html/821-1461/ld-1.html

So, we'd have to check for valid linker options first?

Andreas