1 files changed, 90 insertions, 0 deletions
diff --git a/toolkit/xre/SafeMode.h b/toolkit/xre/SafeMode.h
new file mode 100644
index 0000000000..9323ff1a9c
--- /dev/null
+++ b/toolkit/xre/SafeMode.h
@@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SafeMode_h
+#define mozilla_SafeMode_h
+
+// NB: This code must be able to run apart from XPCOM
+
+#include "mozilla/CmdLineAndEnvUtils.h"
+#include "mozilla/Maybe.h"
+
+#if defined(XP_WIN)
+#  include "mozilla/PolicyChecks.h"
+#  include <windows.h>
+#endif  // defined(XP_WIN)
+
+// Undo X11/X.h's definition of None
+#undef None
+
+namespace mozilla {
+
+enum class SafeModeFlag : uint32_t {
+  None = 0,
+  Unset = (1 << 0),
+  NoKeyPressCheck = (1 << 1),
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(SafeModeFlag)
+
+template <typename CharT>
+inline Maybe<bool> IsSafeModeRequested(
+    int& aArgc, CharT* aArgv[],
+    const SafeModeFlag aFlags = SafeModeFlag::Unset) {
+  CheckArgFlag checkArgFlags = CheckArgFlag::None;
+  if (aFlags & SafeModeFlag::Unset) {
+    checkArgFlags |= CheckArgFlag::RemoveArg;
+  }
+
+  ArgResult ar = CheckArg(aArgc, aArgv, "safe-mode", nullptr, checkArgFlags);
+  if (ar == ARG_BAD) {
+    return Nothing();
+  }
+
+  bool result = ar == ARG_FOUND;
+
+#if defined(XP_WIN)
+  // If the shift key is pressed and the ctrl and / or alt keys are not pressed
+  // during startup, start in safe mode. GetKeyState returns a short and the
+  // high order bit will be 1 if the key is pressed. By masking the returned
+  // short with 0x8000 the result will be 0 if the key is not pressed and
+  // non-zero otherwise.
+  if (!(aFlags & SafeModeFlag::NoKeyPressCheck) &&
+      (GetKeyState(VK_SHIFT) & 0x8000) && !(GetKeyState(VK_CONTROL) & 0x8000) &&
+      !(GetKeyState(VK_MENU) & 0x8000) &&
+      !EnvHasValue("MOZ_DISABLE_SAFE_MODE_KEY")) {
+    result = true;
+  }
+
+  if (result && PolicyCheckBoolean(L"DisableSafeMode")) {
+    result = false;
+  }
+#endif  // defined(XP_WIN)
+
+#if defined(XP_MACOSX)
+  if (!(aFlags & SafeModeFlag::NoKeyPressCheck) &&
+      (GetCurrentEventKeyModifiers() & optionKey) &&
+      !EnvHasValue("MOZ_DISABLE_SAFE_MODE_KEY")) {
+    result = true;
+  }
+#endif  // defined(XP_MACOSX)
+
+  // The Safe Mode Policy should not be enforced for the env var case
+  // (used by updater and crash-recovery).
+  if (EnvHasValue("MOZ_SAFE_MODE_RESTART")) {
+    result = true;
+    if (aFlags & SafeModeFlag::Unset) {
+      // unset the env variable
+      SaveToEnv("MOZ_SAFE_MODE_RESTART=");
+    }
+  }
+
+  return Some(result);
+}
+
+}  // namespace mozilla
+
+#endif  // mozilla_SafeMode_h