31/10/2018 19:26, Ferruh Yigit: > On 10/31/2018 6:26 PM, Ferruh Yigit wrote: > > On 10/31/2018 5:16 PM, Thomas Monjalon wrote: > >> 31/10/2018 18:19, Ferruh Yigit: > >>> rte_strerror uses strerror_r(), and strerror_r() has two version of it. > >>> - XSI-compliant version, (_POSIX_C_SOURCE >= 200112L) && ! _GNU_SOURCE > >>> - GNU-specific version > >>> > >>> Those two has different return types, so the exiting return type check > >>> is not correct for GNU-specific version. > >>> > >>> And this is causing failure in errno_autotest unit test. > >>> > >>> Adding different implementation for FreeBSD and Linux. > >>> > >>> Fixes: 016c32bd3e3d ("eal: cleanup strerror function") > >>> Cc: sta...@dpdk.org > >>> > >>> Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com> > >>> --- > >>> --- a/lib/librte_eal/common/eal_common_errno.c > >>> +++ b/lib/librte_eal/common/eal_common_errno.c > >>> default: > >>> +#ifdef RTE_EXEC_ENV_BSDAPP > >>> if (strerror_r(errnum, ret, RETVAL_SZ) != 0) > >>> snprintf(ret, RETVAL_SZ, "Unknown error%s %d", > >>> sep, errnum); > >>> +#else > >>> + /* > >>> + * _GNU_SOURCE version, error string is not always > >>> + * strored in "ret" buffer, need to use return value > >>> + */ > >>> + ret = strerror_r(errnum, ret, RETVAL_SZ); > >>> +#endif > >> > >> Why not use the return value in both cases? > >> > >> Why not writing an error message in Linux case? > > > > "man strerror_r" has more details, but briefly, > > > > The XSI-compliant strerror_r() function returns 0 on success. GNU one > > returns > > the pointer to string. > > > > The XSI-compliant can return an empty buffer, GNU one always return a > > string, > > either proper error string or "Unknown .." one.
You say "GNU one always return a string" The comment says: _GNU_SOURCE version, error string is not always strored in "ret" buffer > strerror_r() not portable. An alternative can be not using it at all... It's fine to use it.