Miscellaneous questions

[David Chisnall]

On 3 May 2013, at 13:52, Erik Cederstrand <erik at cederstrand.dk> wrote:

> Not that I'm aware of. mclinker is work in progress and is not yet able to link the kernel. gold should work, but I'm not aware that LTO linking has been tested to work.

I spoke to Diana Chen, who works on MCLinker, on Monday and apparently they do have enough linker script support to link the FreeBSD kernel now, but not the Linux kernel.  They're currently missing version scripts (Luba Tang is working on that).  They were aiming to deliver a linker that can link kernel + world with all of the options that we need for BSDCan, but apparently their schedule has now slipped by about two weeks.

> Apart from this, we need a general solution to having multiple linkers installed and choosing which one to use in general, during buildworld, for ports etc.

I plan on adding a --linker= option to clang for this.  We can also start installing BDF linker as ld-bfd and mclinker as ld-mclinker (or similar) and have /usr/bin/ld be a symlink to one or the other.  

I think shipping a GPL-free 10.0 (with adequate testing) is not feasible in the current timeline, however I would like to have replacements for all of the GPL'd components in tree, even if not used by default, so that downstream people who really care about not having GPL'd stuff can just tweak a build knob.

David