Re: [Qemu-devel] Fix make check breakage (was [PULL 00/14] QMP queue)

[Peter Crosthwaite <peter.crosthwaite@xilinx.com>]

On Wed, Jan 15, 2014 at 7:55 PM, Markus Armbruster <armbru@redhat.com> wrote:
> Luiz Capitulino <lcapitulino@redhat.com> writes:
>
>> On Tue, 14 Jan 2014 17:44:51 +0100
>> Kevin Wolf <kwolf@redhat.com> wrote:
>>
>>> Am 14.01.2014 um 04:38 hat Edgar E. Iglesias geschrieben:
>>> > On Tue, Jan 14, 2014 at 09:27:10AM +1000, Peter Crosthwaite wrote:
>>> > > Ping,
>>> > >
>>> > > Has this one been forgotten or are there issues? PMM had a small
>>> > > comment, but he waived it AFAICT.
>>> >
>>> > Pong,
>>> >
>>> > I've merged it now, thanks!
>>>
>>> I believe it's something in this pull requests that breaks make check.
>>
>> And you're right. But first, let me confirm that we're talking about the
>> same breakage. This is what I'm getting:
>>
>> make tests/check-qom-interface
>> libqemuutil.a(qemu-error.o): In function `error_vprintf':
>> /home/lcapitulino/work/src/upstream/qmp-unstable/util/qemu-error.c:23: undefined reference to `cur_mon'
>> /home/lcapitulino/work/src/upstream/qmp-unstable/util/qemu-error.c:24: undefined reference to `cur_mon'
>> /home/lcapitulino/work/src/upstream/qmp-unstable/util/qemu-error.c:24: undefined reference to `monitor_vprintf'
>> libqemuutil.a(qemu-error.o): In function `error_printf_unless_qmp':
>> /home/lcapitulino/work/src/upstream/qmp-unstable/util/qemu-error.c:47: undefined reference to `monitor_cur_is_qmp'
>> libqemuutil.a(qemu-error.o): In function `error_print_loc':
>> /home/lcapitulino/work/src/upstream/qmp-unstable/util/qemu-error.c:174: undefined reference to `cur_mon'
>> collect2: error: ld returned 1 exit status
>> make: *** [tests/check-qom-interface] Error 1
>>
>> I tried bisecting it, but git bisect weren't capable of finding the
>> culprit. So debugged it, and the problem was introduced by:
>>
>>   commit 594278718323ca7bffaab0fb7fc6c82fa2c1cd5f
>>   Author: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>   Date:   Wed Jan 1 18:49:52 2014 -0800
>>
>>       qerror: Remove assert_no_error()
>>
>
> Are you sure you don't mean commit 5d24ee7 "error: Add error_abort"?
>
>> There isn't nothing really wrong with this commit. The problem seems to
>> be that the tests link against libqemuutil.a and this library pulls in
>> everything from util/. The commit above changed util/error.c to call
>> error_report(),
>
> Yes, 5d24ee7 does that.
>
>>                 which depends on 'cur_mon', which is only made available
>> by monitor.o.
>
> And stubs/mon-set-error.o
>
>> I don't think we want to mess up with including monitor.o on libqemuutil.a.
>> Besides, I now find it a bit weird to call error_report() from an error
>> reporting function. So it's better to just call fprintf(stderr,) instead.
>
> It's not weird at all.  Higher layer calls lower layer.
>
>> Peter, Markus, are you ok with this patch?
>>
>> PS: I do run make check before sending a pull request, and did run this
>>     time too. Not sure how I didn't catch this. Thanks for the report
>>     Kevin!
>>
>> diff --git a/util/error.c b/util/error.c
>> index f11f1d5..7c7650c 100644
>> --- a/util/error.c
>> +++ b/util/error.c
>> @@ -44,7 +44,7 @@ void error_set(Error **errp, ErrorClass err_class, const char *fmt, ...)
>>      err->err_class = err_class;
>>
>>      if (errp == &error_abort) {
>> -        error_report("%s", error_get_pretty(err));
>> +        fprintf(stderr, "%s", error_get_pretty(err));
>>          abort();
>>      }
>>
>> @@ -80,7 +80,7 @@ void error_set_errno(Error **errp, int os_errno, ErrorClass err_class,
>>      err->err_class = err_class;
>>
>>      if (errp == &error_abort) {
>> -        error_report("%s", error_get_pretty(err));
>> +        fprintf(stderr, "%s", error_get_pretty(err));
>>          abort();
>>      }
>>
>> @@ -125,7 +125,7 @@ void error_set_win32(Error **errp, int win32_err, ErrorClass err_class,
>>      err->err_class = err_class;
>>
>>      if (errp == &error_abort) {
>> -        error_report("%s", error_get_pretty(err));
>> +        fprintf(stderr, "%s", error_get_pretty(err));
>>          abort();
>>      }
>>
>> @@ -171,7 +171,7 @@ void error_free(Error *err)
>>  void error_propagate(Error **dst_err, Error *local_err)
>>  {
>>      if (local_err && dst_err == &error_abort) {
>> -        error_report("%s", error_get_pretty(local_err));
>> +        fprintf(stderr, "%s", error_get_pretty(local_err));
>>          abort();
>>      } else if (dst_err && !*dst_err) {
>>          *dst_err = local_err;
>
> Error message screwed up!
>
> Before:
>
>     $ qemu -msg timestamp=on -global i440FX-pcihost.foo=bar
>     2014-01-15T09:50:18.066725Z upstream-qemu: Property '.foo' not found
>     Aborted (core dumped)
>

curious - should the user be able to cause an abort just on command
line misuse like that? My understanding is that assert (and therefore
assert_no_error and error_abort) should be limited to fatal errors
indicating qemu source bugs. Is it ok to report-and-abort a non
recoverable error like this one? If so, theres significant cleanup we
can do as many of us have been using the verbose error-report ->
exit(1) for situations much like this.

> After:
>
>     Property '.foo' not foundAborted (core dumped)
>
> Note the loss of timestamp, name of executable, location, and the final
> newline.  Please fix.
>
> Amazing super-secret trick to get error messages fit for human
> consumption: reproduce them before you commit!  ;-P
>

Short series on list that straightens it all out based on your stub
recommendations.

Regards,
Peter