[PATCH v3 0/3] nolibc: Add dirfd()

[Daniel Palmer]

Add dirfd() to convert a DIR back to an fd for functions like fstatat()
that take an fd.

Change log:
v3 - Split the internal helper into its own commit.
   - test: just stat one child instead of all of them
   - According to POSIX (https://man7.org/linux/man-pages/man3/dirfd.3.html) errno
     should be EINVAL on failure, so closedir() is now untouched as it is setting EBADF.
     This makes the diff a little cleaner too.
   - Replace i with fd in some places so isn't confused with -1.
   - Due to all of the changes I didn't add trailers from v2.
v2 - Fix the name of the dirfd helper, I debated over removing the helper
     as suggested by Thomas but it seems right to have the logic in a single
     place.
     Add test a basic test to make sure dirfd() actually does convert back
     to the expected fd and using dirfd() with fstatat().

Daniel Palmer (3):
  tools/nolibc: Add internal __nolibc_dirfd() helper
  tools/nolibc: Add dirfd()
  selftests/nolibc: Add test for dirfd()

 tools/include/nolibc/dirent.h                | 37 ++++++++++++++----
 tools/testing/selftests/nolibc/nolibc-test.c | 40 ++++++++++++++++++++
 2 files changed, 70 insertions(+), 7 deletions(-)

-- 
2.53.0