Make std* blocking file-descriptors.

runtime/bin/file_win.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 "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/file.h"
 
 #include <fcntl.h>  // NOLINT
@@ skipping 19 matching lines @@
   void set_fd(int fd) { fd_ = fd; }
 
  private:
   int fd_;
 
   DISALLOW_COPY_AND_ASSIGN(FileHandle);
 };
 
 
 File::~File() {
-  // Close the file (unless it's a standard stream).
-  if (handle_->fd() > 2) {
-    Close();
-  }
+  Close();
   delete handle_;
 }
 
 
 void File::Close() {
   ASSERT(handle_->fd() >= 0);
-  int err = close(handle_->fd());
-  if (err != 0) {
-    Log::PrintErr("%s\n", strerror(errno));
+  if (handle_->fd() == _fileno(stdout)) {
+    int fd = _open("NUL", _O_WRONLY);
+    ASSERT(fd >= 0);
+    _dup2(fd, handle_->fd());
+    close(fd);
+  } else {
+    int err = close(handle_->fd());
+    if (err != 0) {
+      Log::PrintErr("%s\n", strerror(errno));
+    }
   }
   handle_->set_fd(kClosedFd);
 }
 
 
 bool File::IsClosed() {
   return handle_->fd() == kClosedFd;
 }
 
 
@@ skipping 61 matching lines @@
     int64_t position = _lseeki64(fd, 0, SEEK_END);
     if (position < 0) {
       return NULL;
     }
   }
   return new File(new FileHandle(fd));
 }
 
 
 File* File::OpenStdio(int fd) {
-  UNREACHABLE();
-  return NULL;
+  switch (fd) {
+    case 1:
+      fd = _fileno(stdout);
+      break;
+    case 2:
+      fd = _fileno(stderr);
+      break;
+    default:
+      UNREACHABLE();
+  }
+  return new File(new FileHandle(fd));
 }
 
 
 bool File::Exists(const char* name) {
   struct __stat64 st;
   const wchar_t* system_name = StringUtils::Utf8ToWide(name);
   bool stat_status = _wstat64(system_name, &st);
   free(const_cast<wchar_t*>(system_name));
   if (stat_status == 0) {
     return ((st.st_mode & S_IFMT) == S_IFREG);
@@ skipping 481 matching lines @@
     return kIdentical;
   } else {
     return kDifferent;
   }
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)