[EXT] Re: Can LTO minor version be updated in backward compatible way ?

[Florian Weimer]

* Richard Biener:

> On Fri, Jul 19, 2019 at 10:30 AM Florian Weimer <fweimer@redhat.com> wrote:
>>
>> * Romain Geissler:
>>
>> > That may fly in the open source world, however I expect some vendors
>> > shipping proprietary code might be fine with assembly/LTO
>> > representation of their product, but not source.
>>
>> They can't ship LTO today anyway due to the format incompatibility, so
>> that's not really an argument against source-based LTO.
>
> Source-based LTO doesn't really work unless you can re-synthesize
> source from the IL.  At least I don't see how you can do whole-program
> analysis on source and then cut it into appropriate pieces, duplicating
> some things and some not to make up for the parallel final compile step.

Oh, I meant using source code only as a portable serialization of the
program, instead of serializing unstable, compiler-specific IR.  If the
whole program does not fit into memory, the compiler will still have to
maintain on-disk data structures, but at least there wouldn't a
compatibility aspect to those anymore.

Thanks,
Florian