svn commit: r292723 - in head: lib/libc share/mk

[Colin Percival]

On 12/25/15 13:03, Daniel Eischen wrote:
> On Fri, 25 Dec 2015, Ed Schouten wrote:
>> 2015-12-25 12:29 GMT+01:00 Colin Percival <cperciva at freebsd.org>:
>>>   Make libxnet.so a symlink to libc.so.  This makes `-lxnet` a no-op, as
>>>   POSIX requires for the c99 compiler.
>>
>> I seem to remember I had some issues in the past where I was linking
>> against libc explicitly. Maybe it had something to do with linking
>> both against -lpthread and -lc, but if you pass in -lc later on the
>> command line, libc overrides the symbols that have to be provided by
>> -lpthread?

I just did some tests with one of my pthread-using tools, and it passes
all of my tests with -lc added before or after -lpthread.  Can you
remember any details of how the problems showed up?  Is it possible that
this has been fixed since then?  I know there's a lot of tricks to make
sure that the right versions of functions get called.

>> If that's (still) the case, would it make sense to just provide
>> libxnet in the form of an empty .a file instead?
> 
> I think that's a good point.  Using -lanything shouldn't introduce an
> unexpected link order.

Yes, adding a dummy library was my first thought, but kib pointed out
that a symlink was much simpler.  Obviously it never occurred to me that
linking to a library which we were going to be linking to anyway would
cause problems...

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid