[PATCH] LTO: introduce object file-based on-disk module format.

[Rafael Espíndola]

>> BTW, what will be producing these files with .go_export and llvm IR?
>> Is in a new GO FE?
>
> This Go frontend: https://github.com/go-llvm/llgo/tree/libgo
>
> I decided to spend some time this weekend trying to teach it LTO.

Interesting.

A higher level question is how relevant the format is to the llvm
project itself. If this was needed just for that one compiler, I would
be tempted to say that the llgo compiler should provide its own
gold/bfd plugin.

I think the proposed format is fairly general and is an useful
addition, but it would be nice to see what others think. Would you
mind sending a quick email to llvmdev with the proposal for supporting
IR in native object format? The reason I think this is general is

* Other languages are likely to have similar use for native files with
custom sections.
* We could use the format for fat objects in LTO of C/C++ where the
plugin can cherry pick functions from the enclosing ELF if they are
cold.

Cheers,
Rafael