Is there a way to invoke the script debugger programmatically?
I want to create a dialog box that offers an option to start the debugger (as if it had reached a breakpoint in one of the callers), similar to the one that QTP offers when it encounters a playback error.
This is for QTP, but i estimate that if one can do this for VBS, it'll work there too.
Updated update
The stop statement does what I want -- except for this (in conjunction with QTP/UFT):
it stops where the stop statement is (and not in the caller's code) (I think I could work around that by putting the function with the stop statement into a file that I load in a way that it won't be jumped into by the debugger (LoadLibrary? ExecuteFile?));
it requires me to have triggered one "real" breakpoint during the run session previously, and continued execution with "Run"/F5.
Does Err.Raise work for what you're trying to achieve?
Related
Is it possible that Pycharm 'save' the whole staus at a breakpoint and allow the customer repeat debugging from there?
Occasionally I may need to debug a complicate bug which need ~2 hours to reach the target function. The multi-process code consists of many nested invoking and loops. The narrowing down process is pretty tricky. The first breakpoint is easy to set up. But if the second breakpoint was not set up correctly. Or there was one more clicking on 'step over' button. The debug session may exit since there was error. That is terrible since I may need another two hours to start another debugging. If Pycharm allow me to 'save' the debug status at the first breakpoint and allow me back to there whatever the current session ends or not it will be great helpful.
If I could catch up abnormal result before the session exit, then I need to step back during Pycharm debugging to figure out the issue. I searched and found out that both visual studio and IntelliJ has this ability. 'Jumping to Cursor' in Pycharm looks a similar solution. So far I don't have a chance to verify it by using a complex case.
So in genearal, what is the best strategy to debug those bugs which take long time to reach the starting point but failure point/reason is unclear? Thanks a lot.
Long story short, I am debugging a big application which I didn't write. It is throwing an error when it runs on the server on which it is supposed to be run, so I am testing on my own machine with the debugger attached to see what happens.
It has thousands of lines of code, and has been running for a couple of hours now. I want to know which line of code is currently executing, so I can get a rough idea of how long is left, but I don't want to Break All as the code is...rickety.
Short of firing watchpoints all over the place in a spray and pray fashion, is there a non-invasive way to see which line of code is executing right now?
Thanks
Process Explorer can show the currently executing line and call stack in the process.
Right-click a process, click Properties, and then click the Threads tab.
I'm trying to use OllyDbg's "Execute Till User Code" feature (which is essential for me) but it never works.
I first tried it on a program which called MessageBoxA. When it called it I paused the program in the debugger and issued OllyDbg to execute till user code, but the program was still paused and completely frozen. I couldn't even click the MessageBox's OK button, or even make it continue from OllyDbg. When I tried too hard to make it continue it just crashed.
So I decided to write an application in NASM (to have complete control) and tried it there. The MessageBoxA popped, I paused, executed till user code, I could press the OK button this time, but OllyDbg didn't pause the program once I did. The program just executed as if nothing happened.
Why doesn't it work and what can I do to solve it?
OllyDbg 1.10 (No Plugins)
Windows 7 Ultimate SP1 64-bit
Update:
I've tried to use OllyDbg 2.0 but the Execute till user code button is completely disabled for some reason.
I ran into the same issue while following Lena's tutorial #4 and I think I've figured it out. When I press Alt+F9 to "Execute Until User Code," I notice that all but one thread in the Threads window (Alt+T) have the suspend flag set. Evidently, Alt+F9 only resumes one thread. Fortunately, OllyDbg has the ability to manually resume the other threads by right clicking on them and selecting "Resume" (or by using the + key). For me, this was sufficient both to unfreeze the dialog and to get OllyDbg to pause immediately after the call to MessageBoxA.
I am writing a Google Chrome extension. One of my content scripts has a little bug that I can't find and the Google Chrome debugger appears to be useless for this purpose. The code stops on an Uncaught typeError: Cannot set property 'value' of null. I can see this by opening the debugger and viewing the console after the code fails. But my content script does not appear in the list of scripts shown in the debugger at this point. There are a lot of scripts shown there, including a big block of scripts in light blue. But none named "profile.js" which is my content script.
I tried "location.reload(); but it simply returns "undefined." I'd love to step thru this code and find the problem but I can't figure out how to do it. I've set alerts to try to track the problem but once I click on the alert, the script continues with no opportunity to invoke the debugger. Based on the result of the alert experiment, it appears the code is failing at the very end. I presume the code is finished by the time the error is caught and the script is no longer available to the debugger.
I tried adding this line to the script: "debugger;" to try and force the debugger to open but there is no change whatever to the execution of the code. It fails as usual and as usual I can open the debugger, find the console message and the big list of scripts that does not include mine.
How can I pause execution of the code using a line in the code itself? I just want to stop execution of the code at the beginning, invoke the debugger, set up some breakpoints, resume execution and monitor some variables. That seems like a pretty simple and do-able request.
Any ideas?
I am trying to launch an application via the ShellExecute() API call. This application contains only a main function which does some processing and exits.
Now I have put DebugBreak() in starting of main. When ShellExecute() is called the application is launched successfully but it does not ask for breaking.
How can I debug my application when launched from other application using ShellExecute()?
I am using VC++ .
If DebugBreak() isn't workign for you, try _CrtDbgBreak(). Note that _CrtDbgBreak only works in a debug build.
_CrtDebugBreak definitely works for me to make a launched process break on startup, although I'm pretty sure DebugBreak does also.
Note that both functions will make it look like the process has crashed, since they raise an exception. That is normal and gives you the opportunity to attach a debugger via the crash dialog. (The crash dialog also lets you terminate the process; don't use that, obviously.)
Also note that if you have a catch-all SEH exception handler around your main then the exception raise by DebugBreak & friends will be swallowed up and the app will simply exit without showing the crash dialog or letting you attach to it.
You can't do this with VC++; with WinDbg this is just .childdbg 1 to debug all child processes. With VC++, you can use Image File Execution Options in a pinch - check out http://codereflect.com/2009/09/20/how-to-debug-child-process-using-windbgvisual-studio/ for more info. Really though, if you've got the time to learn WinDbg, it's much better at this.
you can try this, it's ok in xp system.
app.exe is your application name,
-s1...-s3 is command line arguments.
HINSTANCE hRet = ShellExecute(NULL, L"open", L"vsjitdebugger.exe", L" app.exe -s1 a1 -s2 a2 a3 -s3", szExePath, SW_SHOW);
There is now a Microsoft Child Process Debugging Power Tool.
The method I use for things like this is to embed some interactive code, which you can either delete afterwards, comment out or conditionally enable. In a few cases we have this code enabled by querying an environment variable which is set by the tool that launches the main application. This allows me to click a check box, hit launch and have the breakpoint dialog in seconds.
if (MessageBox(NULL,
_T("Attach the debugger now, then choose Yes to hit a breakpoint"),
_T("Attach Debugger"),
MB_YESNO) == IDYES)
__debugbreak();
This gives you the ability to attach the debugger when the dialog box appears and the option to hit a breakpoint or not. My earlier versions didn't give me the option and after a while I realised some of the time I wanted the breakpoint, and some of the time I didn't.