Re: [libvirt] [PATCH 1/3] Preserve errno across calls to error reporting functions

On 12/23/2010 11:39 AM, Laine Stump wrote: > There are cases when we want log an error message while still > preserving errno for a caller, but the functions that log errors make > system calls that will clear errno. This patch preserves errno during > those most basic error logging functions (corresponding to > virReportSystemError(), virReportOOMError(), networkReportError(), > etc, as well as virStrError()). It does *not preserve errno across > calls to higher level items such as virDispatchError(), as it's > assumed the caller is all finished with any need for errno by the time > it dispatches the error. > const char *virStrerror(int theerrno, char *errBuf, size_t errBufLen) > { > + int save_errno = errno; > + const char *ret; > + > #ifdef HAVE_STRERROR_R > # ifdef __USE_GNU > /* Annoying linux specific API contract */ > - return strerror_r(theerrno, errBuf, errBufLen); > + ret = strerror_r(theerrno, errBuf, errBufLen); > # else > strerror_r(theerrno, errBuf, errBufLen); > - return errBuf; > + ret = errBuf; > # endif > #else > /* Mingw lacks strerror_r and its strerror is definitely not Ah, but gnulib now provides the LGPLv2+ strerror_r-posix module, which not only provides strerror_r on mingw, but also sanitizes the Linux interface into the POSIX compatible interface, so that we could use it to simplify the code. But that's a patch for another day. ACK as-is.