[polly] move detection of polly libs to LLVM

[Tobias Grosser]

On 03/13/2014 05:03 PM, Sebastian Pop wrote:
> Sebastian Pop wrote:
>> Chandler Carruth wrote:
>>> CMake should be perfectly capable of sustaining transitive deps so that if
>>> the tolo deps on the archive, the tool links against the libraries.
>>
>> Good to know.
>> I will try to keep the toplevel LLVM cmake clean.
>
> For reference, here is how this works in the last patchset that I sent out:
>
> In polly's toplevel CMakeFile, we collect in POLLY_LINK_LIBS all the libs we
> need to link with polly.  Then, we make that variable available to the parent
> scope, that is llvm/tools, such that we can link the tools against polly and all
> the dependent libs:
>
> +# Set the variable POLLY_LINK_LIBS in the llvm/tools/ dir.
> +set(POLLY_LINK_LIBS ${POLLY_LINK_LIBS} PARENT_SCOPE)
>
>  From CMake docs:
>
> If PARENT_SCOPE is present, the variable will be set in the scope above the
> current scope. Each new directory or function creates a new scope. This command
> will set the value of a variable into the parent directory or calling function
> (whichever is applicable to the case at hand)

This looks a lot better. I reviewed your latest change.

Tobias