Error checking for Stdio calls

runtime/bin/stdio_win.cc

 // Copyright (c) 2013, 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.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/stdio.h"
 
 namespace dart {
 namespace bin {
 
-int Stdin::ReadByte() {
+bool Stdin::ReadByte(int* byte) {
   HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
   uint8_t buffer[1];
   DWORD read = 0;
-  int c = -1;
-  if (ReadFile(h, buffer, 1, &read, NULL) && (read == 1)) {
-    c = buffer[0];
+  BOOL success = ReadFile(h, buffer, 1, &read, NULL);
+  if (!success && (GetLastError() != ERROR_BROKEN_PIPE)) {
+    return false;
   }
-  return c;
+  *byte = (read == 1) ? buffer[0] : -1;
+  return true;
 }
 
 
-bool Stdin::GetEchoMode() {
+bool Stdin::GetEchoMode(bool* enabled) {
   HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
   DWORD mode;
   if (!GetConsoleMode(h, &mode)) {
     return false;
   }
-  return ((mode & ENABLE_ECHO_INPUT) != 0);
+  *enabled = ((mode & ENABLE_ECHO_INPUT) != 0);
+  return true;
 }
 
 
-void Stdin::SetEchoMode(bool enabled) {
+bool Stdin::SetEchoMode(bool enabled) {
   HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
   DWORD mode;
   if (!GetConsoleMode(h, &mode)) {
-    return;
+    return false;
   }
   if (enabled) {
     mode |= ENABLE_ECHO_INPUT;
   } else {
     mode &= ~ENABLE_ECHO_INPUT;
   }
-  SetConsoleMode(h, mode);
+  return SetConsoleMode(h, mode);
 }
 
 
-bool Stdin::GetLineMode() {
+bool Stdin::GetLineMode(bool* enabled) {
   HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
   DWORD mode;
   if (!GetConsoleMode(h, &mode)) {
     return false;
   }
-  return (mode & ENABLE_LINE_INPUT) != 0;
+  *enabled = (mode & ENABLE_LINE_INPUT) != 0;
+  return true;
 }
 
 
-void Stdin::SetLineMode(bool enabled) {
+bool Stdin::SetLineMode(bool enabled) {
   HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
   DWORD mode;
   if (!GetConsoleMode(h, &mode)) {
-    return;
+    return false;
   }
   if (enabled) {
     mode |= ENABLE_LINE_INPUT;
   } else {
     mode &= ~ENABLE_LINE_INPUT;
   }
-  SetConsoleMode(h, mode);
+  return SetConsoleMode(h, mode);
 }
 
 
 bool Stdout::GetTerminalSize(intptr_t fd, int size[2]) {
   HANDLE h;
   if (fd == 1) {
     h = GetStdHandle(STD_OUTPUT_HANDLE);
   } else {
     h = GetStdHandle(STD_ERROR_HANDLE);
   }
   CONSOLE_SCREEN_BUFFER_INFO info;
   if (!GetConsoleScreenBufferInfo(h, &info)) {
     return false;
   }
   size[0] = info.srWindow.Right - info.srWindow.Left + 1;
   size[1] = info.srWindow.Bottom - info.srWindow.Top + 1;
   return true;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)
 
 #endif  // !defined(DART_IO_DISABLED)