flto automake

[Brad Bishop]

> On Dec 18, 2018, at 1:08 PM, James Feist <james.feist at linux.intel.com> wrote:
> 
> If you aren't planning on enabling flto in a repo you can ignore this email.
> 
> 
> I've created a new class flto-automake https://github.com/openbmc/meta-phosphor/blob/master/classes/flto-automake.bbclass if you are enabling -flto in an autotools project you might be interested in. When using static libraries you may run into undefined references when building with Yocto. Yocto by default uses:
> 
> export AR = "${HOST_PREFIX}ar"
> export RANLIB = "${HOST_PREFIX}ranlib"
> 
> for AR and RANLIB. This new class replaces these with the gcc equivalent wrappers that can work with the flto object files. This doesn't seem to be an issue for the CI build, it only shows up for Yocto builds. Reference: http://stackoverflow.com/questions/25878407/how-can-i-use-lto-with-static-libraries#comment67660913_25878408
> 
> For Cmake I suggest looking at the way bmcweb handles it in CMakesLists:
> https://github.com/openbmc/bmcweb/blob/master/CMakeLists.txt#L92
> 
> Thanks,
> 
> James

Thanks James

I wonder if this is something they would be interested in upstream.  I’ve copied
the oe-core mailing list for possible comment.

-brad