+ ssize_t ret;
+
+ do {
+ ret = ::write(FD, Ptr, Size);
+
+ if (ret < 0) {
+ // If it's a recoverable error, swallow it and retry the write.
+ // EAGAIN and EWOULDBLOCK are not unambiguously recoverable, but
+ // some programs, such as bjam, assume that their child processes
+ // will treat them as if they are. If you don't want this code to
+ // spin, don't use O_NONBLOCK file descriptors with raw_ostream.
+ if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
+ continue;
+
+ // Otherwise it's a non-recoverable error. Note it and quit.
+ error_detected();
+ break;
+ }
+
+ // The write may have written some or all of the data. Update the
+ // size and buffer pointer to reflect the remainder that needs
+ // to be written. If there are no bytes left, we're done.
+ Ptr += ret;
+ Size -= ret;
+ } while (Size > 0);