Fix debug mode build

libc/calls/poll.c

@@ -0,0 +1,81 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/strace.internal.h"
+#include "libc/dce.h"
+#include "libc/intrin/asan.internal.h"
+#include "libc/sock/internal.h"
+#include "libc/sock/sock.h"
+#include "libc/sysv/errfuns.h"
+
+/**
+ * Waits for something to happen on multiple file descriptors at once.
+ *
+ * Warning: XNU has an inconsistency with other platforms. If you have
+ * pollfds with fd≥0 and none of the meaningful events flags are added
+ * e.g. POLLIN then XNU won't check for POLLNVAL. This matters because
+ * one of the use-cases for poll() is quickly checking for open files.
+ *
+ * Note: Polling works best on Windows for sockets. We're able to poll
+ * input on named pipes. But for anything that isn't a socket, or pipe
+ * with POLLIN, (e.g. regular file) then POLLIN/POLLOUT are always set
+ * into revents if they're requested, provided they were opened with a
+ * mode that permits reading and/or writing.
+ *
+ * Note: Windows has a limit of 64 file descriptors and ENOMEM with -1
+ * is returned if that limit is exceeded. In practice the limit is not
+ * this low. For example, pollfds with fd<0 don't count. So the caller
+ * could flip the sign bit with a short timeout, to poll a larger set.
+ *
+ * @param fds[𝑖].fd should be a socket, input pipe, or conosle input
+ *     and if it's a negative number then the entry is ignored
+ * @param fds[𝑖].events flags can have POLLIN, POLLOUT, POLLPRI,
+ *     POLLRDNORM, POLLWRNORM, POLLRDBAND, POLLWRBAND as well as
+ *     POLLERR, POLLHUP, and POLLNVAL although the latter are
+ *     always implied (assuming fd≥0) so they're ignored here
+ * @param timeout_ms if 0 means don't wait and -1 means wait forever
+ * @return number of items fds whose revents field has been set to
+ *     nonzero to describe its events, or 0 if the timeout elapsed,
+ *     or -1 w/ errno
+ * @return fds[𝑖].revents is always zero initializaed and then will
+ *     be populated with POLL{IN,OUT,PRI,HUP,ERR,NVAL} if something
+ *     was determined about the file descriptor
+ * @asyncsignalsafe
+ * @threadsafe
+ * @norestart
+ */
+int poll(struct pollfd *fds, size_t nfds, int timeout_ms) {
+  int rc;
+  uint64_t millis;
+  if (IsAsan() && !__asan_is_valid(fds, nfds * sizeof(struct pollfd))) {
+    rc = efault();
+  } else if (!IsWindows()) {
+    if (!IsMetal()) {
+      rc = sys_poll(fds, nfds, timeout_ms);
+    } else {
+      rc = sys_poll_metal(fds, nfds, timeout_ms);
+    }
+  } else {
+    millis = timeout_ms;
+    rc = sys_poll_nt(fds, nfds, &millis);
+  }
+  STRACE("poll(%p, %'lu, %'d) → %d% lm", fds, nfds, timeout_ms, rc);
+  return rc;
+}