_set = set()
_add("HAVE_FACCESSAT", "access")
- # Current linux (kernel 3.2, glibc 2.15) doesn't support lchmod.
- # (The function exists, but it's a stub that always returns ENOSUP.)
- # Now, linux *does* have fchmodat, which says it can ignore
- # symbolic links. But that doesn't work either (also returns ENOSUP).
- # I'm guessing that if they fix fchmodat, they'll also add lchmod at
- # the same time. So, for now, assume that fchmodat doesn't support
- # follow_symlinks unless lchmod works.
- if ((sys.platform != "linux") or
- ("HAVE_LCHMOD" in _have_functions)):
- _add("HAVE_FCHMODAT", "chmod")
+ # Some platforms don't support lchmod(). Often the function exists
+ # anyway, as a stub that always returns ENOSUP or perhaps EOPNOTSUPP.
+ # (No, I don't know why that's a good design.) ./configure will detect
+ # this and reject it--so HAVE_LCHMOD still won't be defined on such
+ # platforms. This is Very Helpful.
+ #
+ # However, sometimes platforms without a working lchmod() *do* have
+ # fchmodat(). (Examples: Linux kernel 3.2 with glibc 2.15,
+ # OpenIndiana 3.x.) And fchmodat() has a flag that theoretically makes
+ # it behave like lchmod(). So in theory it would be a suitable
+ # replacement for lchmod(). But when lchmod() doesn't work, fchmodat()'s
+ # flag doesn't work *either*. Sadly ./configure isn't sophisticated
+ # enough to detect this condition--it only determines whether or not
+ # fchmodat() minimally works.
+ #
+ # Therefore we simply ignore fchmodat() when deciding whether or not
+ # os.chmod supports follow_symlinks. Just checking lchmod() is
+ # sufficient. After all--if you have a working fchmodat(), your
+ # lchmod() almost certainly works too.
+ #
+ # _add("HAVE_FCHMODAT", "chmod")
_add("HAVE_FCHOWNAT", "chown")
_add("HAVE_FSTATAT", "stat")
_add("HAVE_LCHFLAGS", "chflags")
/*
* fchmodat() doesn't currently support AT_SYMLINK_NOFOLLOW!
* The documentation specifically shows how to use it,
- * and then says it isn't implemented yet. (glibc 2.15)
+ * and then says it isn't implemented yet.
+ * (true on linux with glibc 2.15, and openindiana 3.x)
*
* Once it is supported, os.chmod will automatically
* support dir_fd and follow_symlinks=False. (Hopefully.)
* and we can't do that in this nested scope. (Macro trickery, sigh.)
*/
fchmodat_nofollow_unsupported =
- result && (errno == ENOTSUP) && !follow_symlinks;
+ result &&
+ ((errno == ENOTSUP) || (errno == EOPNOTSUPP)) &&
+ !follow_symlinks;
}
else
#endif