svn commit: r299090 - in head: etc/mtree include lib/libbluetooth sbin/hastd share/man/man3 sys/dev/xen/blkback sys/kern sys/net sys/sys tests/sys tests/sys/sys usr.sbin/bluetooth/hccontrol

[Bruce Evans]

On Thu, 5 May 2016, Alan Somers wrote:

> On Thu, May 5, 2016 at 10:31 AM, John Baldwin <jhb at freebsd.org> wrote:
>
>> On Wednesday, May 04, 2016 10:34:11 PM Alan Somers wrote:
>>> ...
>>> Log:
>>>   Improve performance and functionality of the bitstring(3) api
>> ...
>> Doesn't switching from bytes to longs break the ABI?  That is, setting bit
>> 9
>> ...
>> Is the API is so little used we don't care?
>
> The API isn't used in any shared libraries, so the only risk would be if
> it's used in a user application where the user's build system doesn't check
> for changes in system libraries, and the user upgrades FreeBSD without
> doing a clean build of his application, right?  Am I missing any other
> scenarios?  Do we need to warn users with a line in UPDATING or something?

All scenarios where the binary format is used for data layouts that live
for more than a few microseconds.  Little things like file systems and
networks.

> This is similar to an upgrade of the C++ compiler.  C++ objects built by
> different minor versions of the compiler aren't guaranteed to be compatible.

So C++ is also unsuitable for little things like file systems and networks
:-).

Bruce