[llvm-commits] [llvm] r74284 - in /llvm/trunk: cmake/config-ix.cmake include/llvm/Config/config.h.cmake - cmake bug?

[Douglas Gregor]

On Jun 26, 2009, at 10:50 AM, Xerxes Rånby wrote:

> Hi Doug.
>
> Im having some issues with these two test when implemented using  
> check_symbol_exists(), they both fail when they should not.
> cd llvm
> svn up
> cd ..
> mkdir llvm-build
> cd llvm-build
> cmake ../llvm
> ...
> -- Looking for pthread_create in pthread
> -- Looking for pthread_create in pthread - found
> ...
> -- Looking for pthread_mutex_lock
> -- Looking for pthread_mutex_lock - found
> -- Looking for pthread_rwlock_init
> -- Looking for pthread_rwlock_init - not found.
> -- Looking for pthread_getspecific
> -- Looking for pthread_getspecific - not found.
>
> if i change config-ix.cmake to use  check_library_exists() for the  
> tests then they both succeed on the same machine:
>
> -- Looking for pthread_create in pthread
> -- Looking for pthread_create in pthread - found
> -- Looking for pthread_getspecific in pthread
> -- Looking for pthread_getspecific in pthread - found
> -- Looking for pthread_rwlock_init in pthread
> -- Looking for pthread_rwlock_init in pthread - found
> ...
> -- Looking for pthread_mutex_lock
> -- Looking for pthread_mutex_lock - found
>
> Im a bit puzzled why check_symbol_exists() dont seem to work for  
> these two tests while working to find pthread_mutex_lock.
> Could this be a cmake bug?

No, it was my bug. By default, check_symbol_exists only looks in those  
libraries that are automatically linked into an executable. I should  
have set CMAKE_REQUIRED_LIBRARIES to include pthread. On my platform,  
pthread libraries are automatically linked in, so it magically worked.

Thanks for the fix! I've committed it in r74426.

	- Doug