Re: RISC-V glibc port, v4

[Joseph Myers <joseph at codesourcery dot com>]

On Sat, 13 Jan 2018, Palmer Dabbelt wrote:

> It's been a bit more than two weeks since the last patch set, and I think we're
> starting to get something that's in reasonable shape.  Thanks to Darius for
> putting in a lot of time into the v4.  We've also gotten the test suite in a
> bit better shape: we're down to 200 failures when running natively on Linux,
> and all the test suite failures when running in user mode emulate appear to be
> environment issues.  As far as I know the only remaining issue in our port is
> to triage the test suite failures, most of which we're hoping are just
> deficiencies in our current environment.  Of course, now that I've said that
> I'm sure we'll find a bunch of bugs all over the place :)

Although no more than about 20 architecture-specific failures (for each 
configuration tested) should be expected for a port in reasonable shape 
for inclusion, even before that point it makes sense to provide the list 
of failures, as some failures may point reviewers to specific issues with 
the port - details of test failures are necessary information for a full 
review of a port.  (Even better, also make the "make check" output and the 
.out files for failed tests available somewhere.)

> Thanks to everyone who has helped review and contributed to our port.  Like
> usual I believe we've taken everything into account (and hopefully Darius' hit
> rate is a bit better than mine), but if we've missed anything feel free to ping
> it and we'll take another look.

* This version is still missing leading __ on the parameter names for 
__riscv_flush_icache in sys/cachectl.h.

* Of the pieces of multi-ABI support I mentioned in 
<https://sourceware.org/ml/libc-alpha/2018-01/msg00008.html>, you're 
missing dl-cache.h and an ldd_rewrite_script setting.  (To test all this 
you need to set up a system with libraries for multiple ABIs installed in 
the appropriate directories, run ldconfig and make sure that the libraries 
for the different ABIs are properly listed in the cache with the right 
flags set on them - and that ldd installed with glibc for one ABI works 
properly on binaries for both that and the other ABI.  The glibc testsuite 
probably doesn't cover any of this.)

* You're missing sysdeps/riscv/nofpu/Implies pointing to ieee754/soft-fp 
(or more nofpu directories than that, if a single such Implies file 
doesn't suffice to get ieee754/soft-fp before the other ieee754 
directories in the sysdeps directory ordering for soft-float 
configurations).

* As I said in 
<https://sourceware.org/ml/libc-alpha/2017-06/msg00645.html>, you should 
not have a riscv/soft-fp directory.  Previous versions got this right, 
this one appears to have gone backwards.

> * Copyright year has been updated to 2018, and "contributed by" lines have been
>   removed.

But you have one in sysdeps/unix/sysv/linux/riscv/readelflib.c (which is 
also missing an explanatory comment before the copyright notice).

-- 
Joseph S. Myers
joseph@codesourcery.com