[PATCH] Improve test coverage of strnlen function

[Sunil Pandey]

On Wed, Jun 2, 2021 at 10:33 AM Noah Goldstein <goldstein.w.n@gmail.com>
wrote:

> On Wed, Jun 2, 2021 at 1:26 PM Noah Goldstein <goldstein.w.n@gmail.com>
> wrote:
> >
> > On Wed, Jun 2, 2021 at 12:13 PM Sunil K Pandey via Libc-alpha
> > <libc-alpha@sourceware.org> wrote:
> > >
> > > This patch covers the following condition:
> > >
> > > Strings start with different alignments and end with less than 512 byte
> > > length.
> > > ---
> > >  string/test-strnlen.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > > diff --git a/string/test-strnlen.c b/string/test-strnlen.c
> > > index d70faa26ab..20e645893a 100644
> > > --- a/string/test-strnlen.c
> > > +++ b/string/test-strnlen.c
> > > @@ -271,6 +271,10 @@ test_main (void)
> > >        do_test (1, 1 << i, 5000, BIG_CHAR);
> > >      }
> > >
> > > +  for (i = 1; i <= 127; i++)
> >
> > I think it makes sense to either include 0 or 128 for alignments
> > as in some implementations (x86 avx2/evex for example)
> > that is a unique case.
> >
> > > +    for (size_t length = i; length < 512; length++)
> > > +      do_test (i, length, 512, BIG_CHAR);
> I think it would also make sense to include multiple length.
> Again in the x86_64 avx2/evex implementations for example
> there are 4 cases for handling remaining length:
>  [1,32], [33,64], [65,96], and [97, 128].
>
> As well it might be useful to have tests for position of
> null > length as well.
>
> >
> > Might be strengthened a bit with additional test case
> > in inner loop:
> > do_test (getpagesize() - i, length, 512, BIG_CHAR);
> >
> > > +
> > >    do_random_tests ();
> > >    do_page_tests ();
> > >    do_page_2_tests ();
> > > --
> > > 2.31.1
> > >
>
Sure, will submit a v2 patch which will incorporate all these cases.