Hi/2. Bruno Haible wrote: > KO Myung-Hun wrote: >>> dirfd is specified at >>> https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirfd.html >>> Which says that if "The dirp argument does not refer to a valid directory >>> stream" >>> the function may fail with error EINVAL. It may alternatively simply crash >>> ("the behavior is undefined"). >> >> Then, gnulib decided to crash instead of returning -1 with setting errno >> to EINAL if dir_p has the garbage value which is not returned by opendir() ? > > Correct. > > If a function that takes a pointer as argument wants to reject all invalid > values reliably, without crashing, the only possible implementation is one > that keeps a list of the valid values. This uses O(N) of space and — unless > hashing or a binary tree is used — O(N) of time per operation. Therefore > in these cases POSIX does not require this sort of behaviour, but makes > it optional: > https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirfd.html > https://pubs.opengroup.org/onlinepubs/9699919799/functions/closedir.html > https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_close.html > https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_close.html > https://pubs.opengroup.org/onlinepubs/9699919799/functions/pclose.html > https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_close.html > > It is only mandatory here: > https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlclose.html > > Gnulib's goal is that correct programs that use POSIX functions run fine > also on native Windows, kLIBC, etc. It is not a goal to make the Gnulib > replacement functions be "safer" in the sense that they will detect > programming problems better than glibc does. We assume that the application > development happens on glibc systems and that the debugging facilities > (valgrind, ltrace, strace, etc.) there are sufficient; then the application > will not have such logic mistakes. >
Ok. I've understood Gnulib's goal. Thanks for your explanation. I'll try to modify kLIBC codes. -- KO Myung-Hun Korean OS/2 User Community : https://www.os2.kr/
