Re: perror.m4 test

[Eric Blake]

On 10/15/2011 03:49 AM, Bruno Haible wrote:
> Hi Eric,
>
> Daniel Richard G. wrote:
> > > > * "checking whether perror matches strerror": strerror(-1) returns
> > > >    an invalid pointer, and attempting to puts() this yields SIGBUS.
> > > >    (Wouldn't it be safer to pass EPERM or something similarly
> > > >    universal?)
> > >
> > > This is the purpose of the test: testing whether you can safely pass
> > > invalid error number, such as -1, to strerror.
> >
> > I thought it was to test that perror() and strerror() gave the
> > same output.
> >
> > Note that currently, the test passes despite the SIGBUS. It should
> > probably check that $? = 0 before comparing stdout vs. stderr.
>
> I'm not sure. This test is about perror(). Should it fail just because
> strerror returns an invalid pointer? Eric, what do you think?

perror() is required to give output containing the same string as 
strerror, and strerror() is required to give a valid string (possible 
"") on all values, including -1.  Since -1 gives SIGBUS, then both 
strerror and perror need to be replaced on this platform, and the test 
needs to be fixed to recognize that a test that dies from a signal 
indicates failure.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org