[OE-core] non-standard library locations and rpath

[Jack Mitchell]

On 05/12/16 10:44, Jack Mitchell wrote:
> On 02/12/16 07:08, Khem Raj wrote:
>> On Thu, Dec 1, 2016 at 8:18 AM, Jack Mitchell <ml at embed.me.uk> wrote:
>>> I'm having some troubles with shared library, shared library
>>> dependencies
>>> and rpaths. I have libfoo, which depends on libbar when I try to link
>>> libfoo
>>> with my app, it requires libbar to be found. libbar is in a non-standard
>>> location, /usr/local/bar when I compiled libfoo, I used -Wl,rpath-link
>>> ${STAGING_SYSROOT}/usr/local/bar and -Wl,rpath /usr/local/bar. Now
>>> when I
>>> come to try link my app with libfoo, it fails to link as it can't find
>>> libbar, which I assume means the rpath in libfoo isn't being properly
>>> prepending with sysroot what is the proper way to support this in OE? My
>>> library has the following rpath information:
>>>
>>> 0x0000000f (RPATH) Library rpath: [$ORIGIN/../lib:/usr/local/bar]
>>>
>>> So why isn't the rpath being prepended with the sysroot when I
>>> compile my
>>> app and link libfoo? The apps build system is using cmake, but this
>>> should
>>> be a built in linker feature, correct?
>>
>> Only first path ( before :) is relative to location of binary at runtime
>>
>
> Exactly, so how can you make an OE build use the rpaths of libs that
> point to the build sysroot. What I have at the moment is
>
> 0x0000000f (RPATH) Library rpath: [$ORIGIN/../lib:/usr/local/bar]
>
> Which would be correct if I was linking on the target. However when OE
> sees the rpath in it's cross compile environment it should prepend it
> with the build sysroot so you end up with something like
>
> 0x0000000f (RPATH) Library rpath:
> [$ORIGIN/../lib:/path/to/build/sysroot/usr/local/bar]
>
> And then the SDK should end up with something like
>
> 0x0000000f (RPATH) Library rpath:
> [$ORIGIN/../lib:/path/to/sdk/sysroot/usr/local/bar]
>
> Is this what is expected to happen, or am I stumbling into an
> unsupported scenario.
>
> Cheers,

I think basically what I'm saying is that does the linker prepend it's 
--sysroot value to absolute rpaths, and if not, should it?