Extend dart:io error handling to all socket functions

runtime/bin/socket_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <arpa/inet.h>
 #include <errno.h>
 #include <netdb.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 77 matching lines @@
 
 
 intptr_t Socket::GetPort(intptr_t fd) {
   ASSERT(fd >= 0);
   struct sockaddr_in socket_address;
   socklen_t size = sizeof(socket_address);
   if (TEMP_FAILURE_RETRY(
           getsockname(fd,
                       reinterpret_cast<struct sockaddr *>(&socket_address),
                       &size))) {
-    fprintf(stderr, "Error getsockname: %s\n", strerror(errno));
     return 0;
   }
   return ntohs(socket_address.sin_port);
 }
 
 
+void Socket::GetError(intptr_t fd, OSError* os_error) {
+  int len = sizeof(errno);
+  getsockopt(fd,
+             SOL_SOCKET,
+             SO_ERROR,
+             &errno,
+             reinterpret_cast<socklen_t*>(&len));
+  os_error->SetCodeAndMessage(OSError::kSystem, errno);
+}
+
+
 intptr_t Socket::GetStdioHandle(int num) {
   return static_cast<intptr_t>(num);
 }
 
 
 const char* Socket::LookupIPv4Address(char* host, OSError** os_error) {
   // Perform a name lookup for an IPv4 address.
   struct addrinfo hints;
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = AF_INET;
   hints.ai_socktype = SOCK_STREAM;
   hints.ai_protocol = IPPROTO_TCP;
   struct addrinfo* info = NULL;
   int status = getaddrinfo(host, 0, &hints, &info);
   if (status != 0) {
     ASSERT(*os_error == NULL);
     *os_error = new OSError(status,
                             gai_strerror(status),
                             OSError::kGetAddressInfo);
-    (*os_error)->set_code(status);
-    (*os_error)->SetMessage(gai_strerror(status));
     return NULL;
   }
   // Convert the address into IPv4 dotted decimal notation.
   char* buffer = reinterpret_cast<char*>(malloc(INET_ADDRSTRLEN));
   sockaddr_in *sockaddr = reinterpret_cast<sockaddr_in *>(info->ai_addr);
   const char* result = inet_ntop(AF_INET,
                                  reinterpret_cast<void *>(&sockaddr->sin_addr),
                                  buffer,
                                  INET_ADDRSTRLEN);
   if (result == NULL) {
@@ skipping 49 matching lines @@
   struct sockaddr clientaddr;
   socklen_t addrlen = sizeof(clientaddr);
   socket = TEMP_FAILURE_RETRY(accept(fd, &clientaddr, &addrlen));
   if (socket < 0) {
     fprintf(stderr, "Error Accept: %s\n", strerror(errno));
   } else {
     FDUtils::SetNonBlocking(socket);
   }
   return socket;
 }