[llvm] Add raw_socket_stream (PR #73603)

[Michael Spencer via llvm-commits]

================
@@ -942,6 +955,154 @@ bool raw_fd_stream::classof(const raw_ostream *OS) {
   return OS->get_kind() == OStreamKind::OK_FDStream;
 }
 
+//===----------------------------------------------------------------------===//
+//  raw_socket_stream
+//===----------------------------------------------------------------------===//
+
+int raw_socket_stream::MakeServerSocket(StringRef SocketPath,
+                                        unsigned int MaxBacklog,
+                                        std::error_code &EC) {
+
+#ifdef _WIN32
+  SOCKET MaybeWinsocket = socket(AF_UNIX, SOCK_STREAM, 0);
+#else
+  int MaybeWinsocket = socket(AF_UNIX, SOCK_STREAM, 0);
+#endif // defined(_WIN32)
+
+#ifdef _WIN32
+  if (MaybeWinsocket == INVALID_SOCKET) {
+#else
+  if (MaybeWinsocket == -1) {
+#endif // _WIN32
+    std::string Msg = "socket create error" + std::string(strerror(errno));
+    std::perror(Msg.c_str());
+    std::cout << Msg << std::endl;
+    EC = std::make_error_code(std::errc::connection_aborted);
+    return -1;
+  }
+
+  struct sockaddr_un Addr;
+  memset(&Addr, 0, sizeof(Addr));
+#ifndef _WIN32
+  Addr.sun_family = AF_UNIX;
+#endif // _WIN32
+  strncpy(Addr.sun_path, SocketPath.str().c_str(), sizeof(Addr.sun_path) - 1);
+
+  if (bind(MaybeWinsocket, (struct sockaddr *)&Addr, sizeof(Addr)) == -1) {
+    if (errno == EADDRINUSE) {
+      ::close(MaybeWinsocket);
+      EC = std::make_error_code(std::errc::address_in_use);
+    } else {
+      EC = std::make_error_code(std::errc::inappropriate_io_control_operation);
+    }
+    return -1;
+  }
+
+  if (listen(MaybeWinsocket, MaxBacklog) == -1) {
+    EC = std::make_error_code(std::errc::address_not_available);
+    return -1;
+  }
+#ifdef _WIN32
+  return _open_osfhandle(MaybeWinsocket, 0);
+#else
+  return MaybeWinsocket;
+#endif // _WIN32
+}
+
+int GetSocketFD(StringRef SocketPath, std::error_code &EC) {
+#ifdef _WIN32
+  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 // _WIN32
+    std::string Msg = "socket create error" + std::string(strerror(errno));
+    std::perror(Msg.c_str());
+    EC = std::make_error_code(std::errc::connection_aborted);
+    return -1;
+  }
+
+  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);
+
+  int status = connect(MaybeWinsocket, (struct sockaddr *)&Addr, sizeof(Addr));
+  if (status == -1) {
+    std::string Msg = "socket connect error" + std::string(strerror(errno));
+    std::perror(Msg.c_str());
+    EC = std::make_error_code(std::errc::connection_aborted);
+    return -1;
+  }
+#ifdef _WIN32
+  return _open_osfhandle(MaybeWinsocket, 0);
+#else
+  return MaybeWinsocket;
+#endif // _WIN32
+}
+
+static int ServerAccept(int FD) {
+  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
+  return AcceptFD;
+}
+
+// Server
+// Call raw_fd_ostream with ShouldClose=false
+raw_socket_stream::raw_socket_stream(int SocketFD, StringRef SockPath,
+                                     std::error_code &EC)
+    : raw_fd_ostream(ServerAccept(SocketFD), true) {
+  SocketPath = SockPath;
+  ShouldUnlink = true;
+}
+
+// Client
+raw_socket_stream::raw_socket_stream(StringRef SockPath, std::error_code &EC)
+    : raw_fd_ostream(GetSocketFD(SockPath, EC), true, true,
+                     OStreamKind::OK_OStream) {
+  SocketPath = SockPath;
+  ShouldUnlink = false;
+}
+
+raw_socket_stream::~raw_socket_stream() {
+  if (ShouldUnlink) {
+    unlink(SocketPath.str().c_str());
+  }
+}
+
+Expected<std::string> raw_socket_stream::read_impl() {
----------------
Bigcheese wrote:

This should just be using `raw_fd_stream::read`. If the `_open_osfhandle` tricks don't end up working, then we can use the actual `SOCKET` value and add a `bool IsWindowsSocket` to `raw_fd_ostream` to handle the difference.

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