I am curious how to execute previous line of code while debugging?
Currently, I see the following buttons:
- Step over;
- Step into;
- Force step into;
- Step out;
but no button "Step previous".
By default, you cannot advance backwards while debugging code. Since code runs are temporal, one should be able to re-run the code that they're debugging to narrow in on what specifically they want to observe in the debugger.
However, if you really want to be able to debug and step backwards, then the Chronon plugin is a viable option. Note that you won't be dropped into a debug context immediately, and you won't be able to access any live evaluation, but this will allow you to debug your code by stepping forwards and backwards.
You could Drop Frame - it will return you to a previous method, so you can step on that line again. See When using the Java debugger in Intellij what does "Drop Frame" mean?
Related
Currently i'm on a project which has some main loop which is quite slow. Putting a breakpoint into it implicates i have to press F9 each time, and there are a lot of iterations. What i imagine is to see the program 'move' on one of my screens, without wondering if it is stuck or not.
I already have log outputs and so on, my question really focuses on this 'show debug without stop' feature.
What i imagine is to see in this main loop the current line highlighted as i it was a line-by-line execution, but without breakpoints and without going down in the subcalls.
Does any of you know a way to do something like this or wish the same thing ?
Thanks !
Your Debug tool window has a "Mute breakpoints" control:
If you leave it ON, your application won't stop at breakpoints. You can switch it off later once you reach the point where you actually want to start debugging (e.g. mute breakpoints while the app is doing all the initial loading tasks, while you navigate to the screen you want to debug etc. and then unmute them).
I'm not quite sure this is it but , how about disabling focus on breakpoint:
Put your cursor on the line you'd like to breakpoint and hit ctrl-shift-f8 (on a pc). You can choose not to suspend when a breakpoint is hit, and/or you can add logging that the breakpoint was triggered. If you need to, you can add a condition that must be met before the breakpoint is triggered.
Here's what this looks like for me:
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.
i coded a big project that runs when I open it in Debug or Release Mode, but when i open it without Debugging (ctrl + f5) it crashs. I searched a long time to find the heap error, but didnt find anything. The problem is i need the running .exe of the programm, so i wanted to ask if there is a possibility to link the windows debugger to the .exe so it always starts with it.
If it doesn't crash right away, maybe this helps:
You can run the executable.
Open your solution in visual studio. Make sure it's the same build.
Open the DEBUG menu and click attach to process.
A window will open, listing all processes that are running. Select the executable that's crashing
Click the DEBUG menu again and select Exceptions (ctrl-alt-E)
Make sure the checkbox "Thrown" is checked for Common Language Runtime Exceptions
Now crash your application.. It will halt at the line that causes it.
Also look for environment directives. like #IF DEBUG #END IF. or #IF RELEASE That kind of stuff. Tricked me a couple of times too..
Good luck. Hope this helps!
You can do various things. First make sure you have a "big out try block" in main. i.e. put the main logic in a try can catch exceptions and report these clearly. This probably isn't what's happening in your case.
You can attach a debugger - including Visual Studio, to a running process - see the "Attach to process" option under the debug menu. If it's built with debug symbols, which you can do, even for release code this may help. If it's optimised you may find it difficult though.
Finally, you could generate a crash dump and inspect that after it's failed. See docs on MiniDumpWriteDump. There are several examples on its usage. Or you can install an abort handler: See here. This mentions _set_abort_behavior which if invoked with _CALL_REPORTFAULT will generate a crash dump too.
Where XCode generate error for application crash ?
I'm crazyng ! My application when open second file xib with webview then it crash. But I don't know why ? how can i Know where is error ?
You need to learn how to use the debugger in Xcode.
Run your app under the debugger then instead if simply getting a stack trace Xcode will stop at the line the fault occurs and show you your code and variables. You can then examine the contents of your variables, the call tree, etc. and hunt down the problem.
Once you know the general area of the problem you can place breakpoints to pause your application before the problem occurs and check whether your variables have the values expected etc. Then you can run till the next breakpoint, or step through your code a line at a time.
You can add code, such as NSAssert's and NSLog's to your app to check progress and display information without stopping the run, etc.
It's a process, and some problems will be harder to track down, but you'll get quicker at it with practice.
The Xcode documentation will tell you all about the debugger.
HTH
Usually, this works, but in addition to my own code there a lot of machine code too, which doesn't really help me out with debugging my own program logic.
Is there a way to step through only my own code?
First put a breakpoint where you want to start step over.After the breakpoint ,Use this button to step over through the code.The play button just runs till the next breakpoint
You probably want to be using the next command or "step over" button in the debugger UI instead of step or "step into" to avoid stepping into each function as you debug. You might still want to step into your own functions, of course, but next will let you step over framework functions instead of diving into their assembly.