[dart:io] Move Platform.ansiSupported to {Stdin,Stdout}.supportsAnsiEscapes

runtime/bin/platform_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(HOST_OS_WINDOWS)
 
 #include "bin/platform.h"
 
 #include <crtdbg.h>
@@ skipping 65 matching lines @@
   static void SaveAndConfigureConsole() {
     MutexLocker ml(platform_win_mutex_);
     // Set both the input and output code pages to UTF8.
     ASSERT(saved_output_cp_ == -1);
     ASSERT(saved_input_cp_ == -1);
     saved_output_cp_ = GetConsoleOutputCP();
     saved_input_cp_ = GetConsoleCP();
     SetConsoleOutputCP(CP_UTF8);
     SetConsoleCP(CP_UTF8);
 
-    ansi_supported_ = true;
+    // Try to set the bits for ANSI support, but swallow any failures.
     HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
     DWORD out_mode;
     if ((out != INVALID_HANDLE_VALUE) && GetConsoleMode(out, &out_mode)) {
       const DWORD request = out_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING;
-      ansi_supported_ = ansi_supported_ && SetConsoleMode(out, request);
-    } else {
-      ansi_supported_ = false;
+      SetConsoleMode(out, request);
     }
-
     HANDLE in = GetStdHandle(STD_INPUT_HANDLE);
     DWORD in_mode;
     if ((in != INVALID_HANDLE_VALUE) && GetConsoleMode(in, &in_mode)) {
       const DWORD request = in_mode | ENABLE_VIRTUAL_TERMINAL_INPUT;
-      ansi_supported_ = ansi_supported_ && SetConsoleMode(in, request);
-    } else {
-      ansi_supported_ = false;
+      SetConsoleMode(in, request);
     }
   }
 
   static void RestoreConsole() {
     MutexLocker ml(platform_win_mutex_);
     RestoreConsoleLocked();
   }
 
-  static bool ansi_supported() { return ansi_supported_; }
-
  private:
   static Mutex* platform_win_mutex_;
   static int saved_output_cp_;
   static int saved_input_cp_;
-  static bool ansi_supported_;
 
   static void RestoreConsoleLocked() {
     // STD_OUTPUT_HANDLE and STD_INPUT_HANDLE may have been closed or
     // redirected. Therefore, we explicitly open the CONOUT$ and CONIN$
     // devices, so that we can be sure that we are really unsetting
     // ENABLE_VIRTUAL_TERMINAL_PROCESSING and ENABLE_VIRTUAL_TERMINAL_INPUT
     // respectively.
     const intptr_t kWideBufLen = 64;
     const char* conout = "CONOUT$";
     wchar_t widebuf[kWideBufLen];
@@ skipping 44 matching lines @@
     // return an error code and/or set errno.
   }
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformWin);
 };
 
 int PlatformWin::saved_output_cp_ = -1;
 int PlatformWin::saved_input_cp_ = -1;
 Mutex* PlatformWin::platform_win_mutex_ = NULL;
-bool PlatformWin::ansi_supported_ = false;
 
 bool Platform::Initialize() {
   PlatformWin::InitOnce();
   PlatformWin::SaveAndConfigureConsole();
   return true;
 }
 
 
 int Platform::NumberOfProcessors() {
   SYSTEM_INFO info;
@@ skipping 76 matching lines @@
   if (GetLastError() != ERROR_SUCCESS) {
     return NULL;
   }
   char* path = StringUtilsWin::WideToUtf8(tmp_buffer);
   // Return the canonical path as the returned path might contain symlinks.
   const char* canon_path = File::GetCanonicalPath(path);
   return canon_path;
 }
 
 
-bool Platform::AnsiSupported() {
-  return PlatformWin::ansi_supported();
-}
-
-
 void Platform::Exit(int exit_code) {
   // TODO(zra): Remove once VM shuts down cleanly.
   ::dart::private_flag_windows_run_tls_destructors = false;
   // Restore the console's output code page
   PlatformWin::RestoreConsole();
   // On Windows we use ExitProcess so that threads can't clobber the exit_code.
   // See: https://code.google.com/p/nativeclient/issues/detail?id=2870
   ::ExitProcess(exit_code);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(HOST_OS_WINDOWS)