Fix build break due to POLLRDHUP not existing on Mac

Summary: fixes hhvm/homebrew-hhvm#110

Reviewed By: fredemmott

Differential Revision: D10240660

fbshipit-source-id: bf9527b7e9246bb8d0adbe29965a9a69c183b636

hphp/runtime/ext/vsdebug/socket_transport.cpp

@@ -435,7 +435,7 @@ void SocketTransport::shutdownSocket(int sockFd, int abortFd) {
     return;
   }
 
-  int eventMask = POLLIN | POLLERR | POLLHUP | POLLRDHUP;
+  int eventMask = POLLIN | POLLERR | POLLHUP | g_platformPollFlags;
   constexpr int abortIdx = 0;
   constexpr int readIdx = 1;
 
@@ -453,8 +453,7 @@ void SocketTransport::shutdownSocket(int sockFd, int abortFd) {
                fds[abortIdx].revents != 0 ||
                fds[readIdx].revents & POLLERR ||
                fds[readIdx].revents & POLLHUP ||
-               fds[readIdx].revents & POLLRDHUP
-               ) {
+               fds[readIdx].revents & g_platformPollFlags) {
 
       break;
     } else if (fds[readIdx].revents & POLLIN) {
@@ -499,7 +498,7 @@ void SocketTransport::waitForConnection(
   // fds[0] will contain the read end of our "abort" pipe. Another thread will
   // write data to tihs pipe to signal it's time for this worker to stop
   // blocking in poll() and terminate.
-  int eventMask = POLLIN | POLLERR | POLLHUP | POLLRDHUP;
+  int eventMask = POLLIN | POLLERR | POLLHUP | g_platformPollFlags;
   fds[0].fd = abortFd;
   fds[0].events = eventMask;
 
@@ -591,6 +590,7 @@ void SocketTransport::waitForConnection(
 }
 
 bool SocketTransport::validatePeerCreds(int newFd, ClientInfo& info) {
+#ifdef SO_PEERCRED
   struct ucred ucred = {0};
   socklen_t len = sizeof(ucred);
 
@@ -656,6 +656,9 @@ bool SocketTransport::validatePeerCreds(int newFd, ClientInfo& info) {
   info.clientUser = std::string(pw.pw_name);
   info.clientPid = ucred.pid;
   return pw.pw_name != nullptr && strlen(pw.pw_name) > 0;
+#else
+  return true;
+#endif
 }
 
 }

hphp/runtime/ext/vsdebug/transport.cpp

@@ -177,11 +177,13 @@ void DebugTransport::processOutgoingMessages() {
 
   pollFds[abortIdx] = {0};
   pollFds[abortIdx].fd = m_abortPipeFd[0];
-  pollFds[abortIdx].events = POLLIN | POLLERR | POLLHUP | POLLRDHUP;
+  pollFds[abortIdx].events =
+    POLLIN | POLLERR | POLLHUP | g_platformPollFlags;
 
   pollFds[transportIdx] = {0};
   pollFds[transportIdx].fd = fd;
-  pollFds[transportIdx].events = POLLOUT | POLLERR | POLLHUP | POLLRDHUP;
+  pollFds[transportIdx].events =
+    POLLOUT | POLLERR | POLLHUP | g_platformPollFlags;
 
   while (true) {
     std::list<std::string> messagesToSend;
@@ -256,7 +258,7 @@ void DebugTransport::processOutgoingMessages() {
         } else {
           // TransportFD hangup or error.
           assert((pollFds[transportIdx].revents &
-                 (POLLERR | POLLHUP | POLLRDHUP)) != 0);
+                 (POLLERR | POLLHUP | g_platformPollFlags)) != 0);
           VSDebugLogger::Log(
             VSDebugLogger::LogLevelInfo,
             "Transport write thread: error event on fd."
@@ -287,7 +289,8 @@ void DebugTransport::processIncomingMessages() {
   // Wait for data to be available, or a termination event to occur.
   constexpr int abortIdx = 0;
   constexpr int transportIdx = 1;
-  int eventMask = POLLIN | POLLERR | POLLHUP | POLLRDHUP;
+
+  int eventMask = POLLIN | POLLERR | POLLHUP | g_platformPollFlags;
   struct pollfd pollFds[2];
   memset(pollFds, 0, sizeof(pollFds));
   pollFds[abortIdx].fd = m_abortPipeFd[0];

hphp/runtime/ext/vsdebug/transport.h

@@ -95,6 +95,12 @@ struct DebugTransport {
   static constexpr char* OutputLevelStdout = "stdout";
   static constexpr char* OutputLevelStderr = "stderr";
 
+  #ifdef POLLRDHUP // Linux-only
+    static constexpr int g_platformPollFlags = POLLRDHUP;
+  #else
+    static constexpr int g_platformPollFlags = 0;
+  #endif
+
 protected:
 
   const std::string wrapOutgoingMessage(