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Question

我有一个MFC SDI应用程序,它在启动期间加载DLL.我只能查看源代码并使用DLL但不能更改和重新编译它.

现在的情况是,每当DLL引发错误时,它将调用exit(),如下所示.

bool Func()
{
  // .. do something here

  if (error) { exit(999); }
}

在我的MFC应用程序中,我设置了SetUnhandledExceptionFilter来处理所有异常,并创建了一个MiniDump用于调试目的.

所以现在的问题是,每当DLL遇到任何错误时,它只会调用状态代码为999的exit(),而我的ExceptionFilter将无法捕获它,因此没有为PostMortem调试创建MiniDump.

我很想知道:
1.我的全局异常处理程序有没有其他方法可以捕获它？
2.我可以覆盖exit()函数,以便在调用时,我调用"throw("error encounter!")"并且我的全局异常处理程序可以捕获它.
3.我尝试在我的MFC应用程序中使用atexit(),每当DLL调用exit()时,我都会注册另一个函数来抛出错误.但似乎这种方式效果不佳.

我真正想做的是,每当DLL遇到错误时,我都希望生成一个MiniDump,这样我就可以进行PostMortem调试.还有什么可能在这种情况下有效吗？

谢谢.

Answer 1

这是我编写的用于在 exit() 函数中放置断点的宏：

Imports System.IO

' Sets breakpoints on all exit functions.  useful for catching library code that 
' calls exit in the debugger.
Sub AddBreakpointsToExit()
    Dim bp As EnvDTE.Breakpoint
    Dim bps As EnvDTE.Breakpoints

    Dim envVar As String = "VS90COMNTOOLS"
    Dim comnTools As String = System.Environment.GetEnvironmentVariable(envVar)
    If (String.IsNullOrEmpty(comnTools)) Then
        Throw New System.Exception("Environment variable '" + envVar + "' doesn't exist.")
    End If
    Dim filePath As String = System.IO.Path.Combine(comnTools, "..\..\VC\crt\src\crt0dat.c")

    ' set exit function names and line #s:
    Dim exitFunctions(0 To 4) As String
    exitFunctions(0) = "exit"
    exitFunctions(1) = "_exit"
    exitFunctions(2) = "_cexit"
    exitFunctions(3) = "_c_exit"

    ' line numbers are based on the Visual Studio 2008 definition.
    ' TODO: check and add options if 2005 or 2010 are differen.t
    Dim exitLines(0 To 4) As Integer
    exitLines(0) = 412
    exitLines(1) = 420
    exitLines(2) = 427
    exitLines(3) = 434

    ' set breakpoints:
    For i = 0 To 3 Step 1
        bps = DTE.Debugger.Breakpoints.Add(File:=filePath, Line:=exitLines(i))
    Next i

End Sub