[llvm] Add raw_socket_stream (PR #73603)

[Michael Spencer via llvm-commits]

================
@@ -942,6 +959,146 @@ bool raw_fd_stream::classof(const raw_ostream *OS) {
   return OS->get_kind() == OStreamKind::OK_FDStream;
 }
 
+//===----------------------------------------------------------------------===//
+//  raw_socket_stream
+//===----------------------------------------------------------------------===//
+
+#ifdef _WIN32
+WSABalancer::WSABalancer() {
+  WSADATA WsaData = {0};
+  if (WSAStartup(MAKEWORD(2, 2), &WsaData) != 0) {
+    llvm::report_fatal_error("WSAStartup failed");
+  }
+}
+
+WSABalancer::~WSABalancer() { WSACleanup(); }
+
+#endif // _WIN32
+
+std::error_code getLastSocketErrorCode() {
+#ifdef _WIN32
+  return std::error_code(::WSAGetLastError(), std::system_category());
+#else
+  return std::error_code(errno, std::system_category());
+#endif
+}
+
+ListeningSocket::ListeningSocket(int SocketFD, StringRef SocketPath)
+    : FD(SocketFD), SocketPath(SocketPath) {}
+
+ListeningSocket::ListeningSocket(ListeningSocket &&LS)
+    : FD(LS.FD), SocketPath(LS.SocketPath) {
+  LS.FD = -1;
+}
+
+Expected<ListeningSocket> ListeningSocket::createUnix(StringRef SocketPath,
+                                                      int MaxBacklog) {
+
+#ifdef _WIN32
+  WSABalancer _;
+  SOCKET MaybeWinsocket = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (MaybeWinsocket == INVALID_SOCKET) {
+#else
+  int MaybeWinsocket = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (MaybeWinsocket == -1) {
+#endif
+    return llvm::make_error<StringError>(getLastSocketErrorCode(),
+                                         "socket create failed");
+  }
+
+  struct sockaddr_un Addr;
+  memset(&Addr, 0, sizeof(Addr));
+  Addr.sun_family = AF_UNIX;
+  strncpy(Addr.sun_path, SocketPath.str().c_str(), sizeof(Addr.sun_path) - 1);
+
+  if (bind(MaybeWinsocket, (struct sockaddr *)&Addr, sizeof(Addr)) == -1) {
+    std::error_code Err = getLastSocketErrorCode();
+    if (Err == std::errc::address_in_use)
+      ::close(MaybeWinsocket);
+    return llvm::make_error<StringError>(Err, "Bind error");
+  }
+  if (listen(MaybeWinsocket, MaxBacklog) == -1) {
+    return llvm::make_error<StringError>(getLastSocketErrorCode(),
+                                         "Listen error");
+  }
+  int UnixSocket;
+#ifdef _WIN32
+  UnixSocket = _open_osfhandle(MaybeWinsocket, 0);
+#else
+  UnixSocket = MaybeWinsocket;
+#endif // _WIN32
+  ListeningSocket ListenSocket(UnixSocket, SocketPath);
+  return ListenSocket;
+}
+
+Expected<std::unique_ptr<raw_socket_stream>> ListeningSocket::accept() {
+  int AcceptFD;
+#ifdef _WIN32
+  SOCKET WinServerSock = _get_osfhandle(FD);
+  SOCKET WinAcceptSock = ::accept(WinServerSock, NULL, NULL);
+  AcceptFD = _open_osfhandle(WinAcceptSock, 0);
+#else
+  AcceptFD = ::accept(FD, NULL, NULL);
+#endif //_WIN32
+  if (AcceptFD == -1)
+    return llvm::make_error<StringError>(getLastSocketErrorCode(),
+                                         "Accept failed");
+  return std::make_unique<raw_socket_stream>(AcceptFD);
+}
+
+ListeningSocket::~ListeningSocket() {
+  if (FD == -1)
+    return;
+  ::close(FD);
+  unlink(SocketPath.c_str());
+}
+
+// Expected?
+Expected<int> GetSocketFD(StringRef SocketPath) {
----------------
Bigcheese wrote:

This should be `static` as it's only used in this file.

https://github.com/llvm/llvm-project/pull/73603