RPI3, error: invalid operand in inline asm: 'rev16 ${0:w}, ${1:w}'

[John F Carr]

On Apr 1, 2019, at 21:59 , bob prohaska <fbsd at www.zefox.net> wrote:
> 
> On Sat, Mar 30, 2019 at 05:50:35PM +0000, John F Carr wrote:
>> 
>> 
>>> On Mar 30, 2019, at 11:23 , bob prohaska <fbsd at www.zefox.net> wrote:
>>> 
>>> In a recent attempt to compile www/chromium on an RPI3 running r345516
>>> compilation stopped with repeated reports of 
>>> 
>>> /usr/include/machine/endian.h:89:19: error: invalid operand in inline asm: 'rev16 ${0:w}, ${1:w}'
>>> 
>>> Chromium compiled on the same host a couple of months ago, but the 
>>> executable failed on a runtime library error. Now attempts to upgrade
>>> stop during compilation. Ports are presently at revision 496949.
>>> 
>>> Thanks for reading, and any guidance.
>>> 
>>> bob prohaska
>> 
>> The swap function at that line in sys/arm64/include/endian.h doesn't look right to me.  I think it should read
>> 
>>  __asm("rev16 %w0, %w1\n" : "=r" (ret) : "r" (w));
>> 
>> instead of
>> 
>>    __asm __volatile("rev16 %w0, %w1\n" : "=&r" (ret), "+r" (v));
>> 
>> Two changes: (1) it doesn't need to be volatile because it has no side effects and (2) the constraints and lack of explicit input operand are wrong.  The other swap functions should have similar changes.
>> 
> 
> Apologies for being obtuse, but is that suggestive of a problem with the
> host system, or a problem with the port?
> 
> Thanks for reading!
> 
> bob prohaska
> 

The problem I mentioned is with the system.  I filed a bug:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236920

If you change the system header /usr/include/machine/endian.h
according to the path in that bug report, does chromium compile?