firebase 崩溃堆栈中的“<OR>”是什么？

Question

Firebase 崩溃堆栈中的 <OR> 是什么？

android.app.Activity.onMenuItemSelected (Activity.java:2566)
android.support.v4.app.FragmentActivity.onMenuItemSelected (FragmentActivity.java)
android.support.v7.app.AppCompatActivity.onMenuItemSelected (AppCompatActivity.java)
android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected (WindowCallbackWrapper.java)
android.support.v7.app.AppCompatDelegateImplV9.onCreate (AppCompatDelegateImplV9.java)
<OR>.setSupportActionBar (AppCompatDelegateImplV9.java)
<OR>.findViewById (AppCompatDelegateImplV9.java)
<OR>.onConfigurationChanged (AppCompatDelegateImplV9.java)
<OR>.setContentView (AppCompatDelegateImplV9.java)
<OR>.setContentView (AppCompatDelegateImplV9.java)
<OR>.onSubDecorInstalled (AppCompatDelegateImplV9.java)
<OR>.onPanelClosed (AppCompatDelegateImplV9.java)
<OR>.onMenuItemSelected (AppCompatDelegateImplV9.java)
<OR>.onMenuModeChange (AppCompatDelegateImplV9.java)
<OR>.startSupportActionModeFromWindow (AppCompatDelegateImplV9.java)
<OR>.onKeyShortcut (AppCompatDelegateImplV9.java)
<OR>.dispatchKeyEvent (AppCompatDelegateImplV9.java)
<OR>.shouldInheritContext (AppCompatDelegateImplV9.java)
<OR>.onCreateView (AppCompatDelegateImplV9.java)
<OR>.openPanel (AppCompatDelegateImplV9.java)
<OR>.initializePanelDecor (AppCompatDelegateImplV9.java)
<OR>.reopenMenu (AppCompatDelegateImplV9.java)
<OR>.closePanel (AppCompatDelegateImplV9.java)
<OR>.callOnPanelClosed (AppCompatDelegateImplV9.java)
<OR>.findMenuPanel (AppCompatDelegateImplV9.java)
<OR>.getPanelState (AppCompatDelegateImplV9.java)
<OR>.performPanelShortcut (AppCompatDelegateImplV9.java)
android.support.v7.view.menu.MenuBuilder.setDefaultShowAsAction (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.dispatchSubMenuSelected (MenuBuilder.java)
<OR>.saveActionViewStates (MenuBuilder.java)
<OR>.getActionViewStatesKey (MenuBuilder.java)
<OR>.setCallback (MenuBuilder.java)
<OR>.addInternal (MenuBuilder.java)
<OR>.createNewMenuItem (MenuBuilder.java)
<OR>.removeItemAtInt (MenuBuilder.java)
<OR>.setExclusiveItemChecked (MenuBuilder.java)
<OR>.findGroupIndex (MenuBuilder.java)
<OR>.dispatchMenuItemSelected (MenuBuilder.java)
<OR>.findInsertIndex (MenuBuilder.java)
<OR>.findItemsWithShortcutForKey (MenuBuilder.java)
<OR>.findItemWithShortcutForKey (MenuBuilder.java)
<OR>.performItemAction (MenuBuilder.java)
<OR>.performItemAction (MenuBuilder.java)
<OR>.close (MenuBuilder.java)
<OR>.onItemVisibleChanged (MenuBuilder.java)
<OR>.setHeaderInternal (MenuBuilder.java)
<OR>.setHeaderTitleInt (MenuBuilder.java)
<OR>.setHeaderIconInt (MenuBuilder.java)
<OR>.setHeaderViewInt (MenuBuilder.java)
android.support.v7.view.menu.MenuItemImpl.invoke (MenuItemImpl.java)
<OR>.setCheckedInt (MenuItemImpl.java)
<OR>.setShowAsActionFlags (MenuItemImpl.java)
android.support.v7.view.menu.MenuBuilder.setDefaultShowAsAction (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.dispatchSubMenuSelected (MenuBuilder.java)
<OR>.saveActionViewStates (MenuBuilder.java)
<OR>.getActionViewStatesKey (MenuBuilder.java)
<OR>.setCallback (MenuBuilder.java)
<OR>.addInternal (MenuBuilder.java)
<OR>.createNewMenuItem (MenuBuilder.java)
<OR>.removeItemAtInt (MenuBuilder.java)
<OR>.setExclusiveItemChecked (MenuBuilder.java)
<OR>.findGroupIndex (MenuBuilder.java)
<OR>.dispatchMenuItemSelected (MenuBuilder.java)
<OR>.findInsertIndex (MenuBuilder.java)
<OR>.findItemsWithShortcutForKey (MenuBuilder.java)
<OR>.findItemWithShortcutForKey (MenuBuilder.java)
<OR>.performItemAction (MenuBuilder.java)
<OR>.performItemAction (MenuBuilder.java)
<OR>.close (MenuBuilder.java)
<OR>.onItemVisibleChanged (MenuBuilder.java)
<OR>.setHeaderInternal (MenuBuilder.java)
<OR>.setHeaderTitleInt (MenuBuilder.java)
<OR>.setHeaderIconInt (MenuBuilder.java)
<OR>.setHeaderViewInt (MenuBuilder.java)
android.support.v7.view.menu.MenuBuilder.setDefaultShowAsAction (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.dispatchSubMenuSelected (MenuBuilder.java)
<OR>.saveActionViewStates (MenuBuilder.java)
<OR>.getActionViewStatesKey (MenuBuilder.java)
<OR>.setCallback (MenuBuilder.java)
<OR>.addInternal (MenuBuilder.java)
<OR>.createNewMenuItem (MenuBuilder.java)
<OR>.removeItemAtInt (MenuBuilder.java)
<OR>.setExclusiveItemChecked (MenuBuilder.java)
<OR>.findGroupIndex (MenuBuilder.java)
<OR>.dispatchMenuItemSelected (MenuBuilder.java)
<OR>.findInsertIndex (MenuBuilder.java)
<OR>.findItemsWithShortcutForKey (MenuBuilder.java)
<OR>.findItemWithShortcutForKey (MenuBuilder.java)
<OR>.performItemAction (MenuBuilder.java)
<OR>.performItemAction (MenuBuilder.java)
<OR>.close (MenuBuilder.java)
<OR>.onItemVisibleChanged (MenuBuilder.java)
<OR>.setHeaderInternal (MenuBuilder.java)
<OR>.setHeaderTitleInt (MenuBuilder.java)
<OR>.setHeaderIconInt (MenuBuilder.java)
<OR>.setHeaderViewInt (MenuBuilder.java)
android.support.v7.widget.ActionMenuView.measureChildForCells (ActionMenuView.java)
<OR>.isOverflowReserved (ActionMenuView.java)
<OR>.generateLayoutParams (ActionMenuView.java)
<OR>.generateLayoutParams (ActionMenuView.java)
<OR>.invokeItem (ActionMenuView.java)
<OR>.initialize (ActionMenuView.java)
<OR>.setMenuCallbacks (ActionMenuView.java)
<OR>.hasSupportDividerBeforeChildAt (ActionMenuView.java)
android.support.v7.view.menu.ActionMenuItemView.onClick (ActionMenuItemView.java)
android.view.View.performClick (View.java:4211)
android.view.View$PerformClick.run (View.java:17446)
android.os.Handler.handleCallback (Handler.java:725)
android.os.Handler.dispatchMessage (Handler.java:92)
android.os.Looper.loop (Looper.java:153)
android.app.ActivityThread.main (ActivityThread.java:5299)
java.lang.reflect.Method.invokeNative (Method.java)
java.lang.reflect.Method.invoke (Method.java:511)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:833)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:600)
dalvik.system.NativeStart.main (NativeStart.java)

Answer 1

<OR> 表示反混淆器无法确定哪个方法是原始方法，因为有几种潜在的可能性。 Firebase 收到混淆的堆栈跟踪，无法使用提供的 Proguard 文件明确确定原始堆栈跟踪。例如，去混淆的堆栈跟踪，例如：

android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected (WindowCallbackWrapper.java)
android.support.v7.view.menu.MenuBuilder.setDefaultShowAsAction (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.addMenuPresenter (MenuBuilder.java)
<OR>.dispatchSubMenuSelected (MenuBuilder.java)

表示第一个堆栈帧已明确反混淆，但堆栈跟踪中的第二个堆栈帧可能是这四种可能性中的任何一种。

在这种情况下，歧义来自以下事实：

没有行号区分方法，
具有不同签名的多个方法被混淆为同一个字符串。

在收缩阶段，Proguard 可以配置为去除行号。要避免此问题，请禁用该功能。

混淆不能保证在没有行号的堆栈跟踪上是可逆的，因为这不是有效 Proguard 映射的要求之一。 Proguard 只保证可逆地混淆 code，而不是 stack traces。 Proguard 文件包含方法签名，因此任何具有非冲突签名的方法都可能被混淆为相同的字符串。

例如：int method(int) 和 String method2(String) 都可能被混淆为 obf。从上下文中，代码反混淆器可以看出 obf 传递的是 int 还是 String，并且可以明确地选择正确的原始方法。对于堆栈跟踪反混淆器，行 MyClass.obf(MyClass.java) 可能来自 MyClass.method(MyClass.java) 或 MyClass.method2(MyClass.java).

firebase 崩溃堆栈中的“<OR>”是什么？

What is '<OR>' in firebase crash stack?

android

firebase

firebase-crash-reporting