I have a windows service that was written in VB6 that I want to attach to and debug in WINDBG.
The service is compiled without optimizations (also all boxes in "Advanced Optimizations" are unchecked), and "Create Symbolic Debug Info" is checked. I have the source file of a class I want to set breakpoints in. I can set breakpoints on some lines but not all... even though the lines where I can't put a breakpoint at don't have anything exotic, simple variable assignments and such.
Regardless, the breakpoints I can set are hit when I run the service with the g command, but when I start to "step over" (F10), the code does some strange leaps and doesn't (or at least doesn't appear to) evaluate all lines...
It seems to me that the source file and the symbols file are out of sync, but I just compiled the project and moved the files over to the computer where I want to debug... What could cause the source files and the pdb/dll file of the project to be out of sync?
Related
When I am debugging in Microsoft Visual Studio 2017 my "Registers" window shows no data available. What can I do to fix this?
As Sneftel stated, you cannot inspect data in the debugger unless you break the execution of the process. During execution, things would be changing far too quickly for any data display to be meaningful.
You can use the "Pause" button in the toolbar to break execution, and then you will see everything in the debugger: the current source line, the contents of registers, your "watch" variables, the full contents of memory in the "Memory" window, etc.
You can also set a breakpoint on a particular line of code, and then execution will break once that point is reached.
Once paused, you can then single-step through your program's code. This means that one line of code (the very next one) will be executed, and then the program will break again so that you can see everything in the debugger. This is an excellent troubleshooting technique—one that you should be well-acquainted with. In fact, I recommend that you single-step through every line of code that you write, just to make sure that it works correctly. You can also modify the contents of registers and variables (or, really, any location in memory) while you are single-stepping, giving yourself a way to test potential bug fixes or even introduce bugs (e.g., invalid input) to see how your code handles them. The default keyboard shortcut for single-step is F11.
You'll find more information about using the debugger, and the available keyboard shortcuts, here on MSDN. As you can see, that article confirms my answer:
Most debugger features, such as viewing variable values in the Locals window or evaluating expressions in the Watch window, are available only while the debugger is paused (also called break mode). When the debugger is paused, your app state is suspended while functions, variables, and objects remain in memory. While in break mode, you can examine the elements' positions and states to look for violations or bugs.
(Edit-and-continue is not available in assembly projects. You will need to stop execution and rebuild if you want to make changes to your code.)
For those with the "No data available" message, you can right click in the Registers window and choose what you want to see (UC, MMX, SSE, etc). It seems like by default there's nothing selected in Visual Studio 2019. At least, on mine there was nothing selected.
Here's my situation. I have an app installed on my system. It's running. I also have the source for this app and I've built it in XCode and had it generate dSYM files. I attached to the process in XCode. I've been trying to set breakpoints of the form "-[ClassName methodName]" (without the quotes) however none of my breakpoints are getting hit. Do I have to somehow point XCode to my symbol file or something?
I have never debugged using that method, but there is a much easier way. You can simply click on the line number of a code-bearing line and a blue arrow (a breakpoint) will appear there. When the application reaches one of these lines with a breakpoint, execution will pause an allow you to step through the code one line at a time.
I want to be able to browse the source and set a debug point without having to hunt for a way to get the file open. I know you can open the original source and detach/reattach the debugger but that is a pain to do every time you run.
If you remember the name of the method you want to debug by heart, you can Add New Breakpoint (Ctrl+B) and type "MyClassName.MyMethodName" (enter). That will put a breakpoint in the beginning of that method, and when you run, as soon as it's hit, the file will open.
This is a pretty niche question, so I am not expecting a huge response...
Basically, I am learning how to use the UDK by following some tutorials, namely this one:
http://forums.epicgames.com/showthread.php?p=27043379#post27043379
So far everything is going pretty well. The only real hangup I've had is getting everything to work in Visual Studio 2005 using this nFringe plugin. For a long time, couldn't get them to work at all. I've gotten into two or three chapters of the tutorial, and I've managed to use Visual Studio to edit the code, but I can't build the scripts within VS; I have to go to UDK Frontend to do that. And worse still, I can only really use Log commands in the unrealscripts to debug anything.
So my question is this: is it even possible to configure these tools in a way that I can put breakpoints in VS and have them be caught when I test the game? I feel as though I don't have something setup correctly.
Yes it is possible. Here are some info which might be useful to you.
First, both your .sln and your .ucproj files must be located in Development/src. Then, under visual studio, right-click your project (.ucproj file in the solution explorer) and open its properties.
You must set, under the General tab:
Target Game: UnrealEngine 3 Mod
UCC Path: ....\Binaries\Win32\UDK.exe
Reference Source Path: ..\Src
Under the Build tab:
check "Build debug scripts"
Under the Debug tab:
Start Game Executable: ....\Binaries\Win32\UDK.exe
Load map at startup: the name of your startup map, without path nor extension
Start with the specified game type: put your GameInfo class used for your mod, ie. MyMod.MyGameInfo
Disable startup movies can be checked to gain time at launch
Enable unpublished mods must be checked.
In your command line, the parameter -vadebug specifies that the breakpoints will be enabled.
After that, you must be able to build your script from Visual, and launch your game by pressing F5.
Breakpoints should work but you can't put them on a variable declaration, you have to put them on a function call, an assignment or a condition statement.
Hope this will help.
I havnt tried using breakpoints yet but I know its possable to build with nfringe and visual studio . You need to add a line to the
udk game / config / udk engine .ini
search for
editpackages
exactly like that , then youll see a block like this
EditPackagesInPath=....\Development\Src
EditPackages=Core
EditPackages=Engine
EditPackages=GFxUI
EditPackages=GameFramework
EditPackages=UnrealEd
EditPackages=GFxUIEditor
EditPackages=IpDrv
EditPackages=OnlineSubsystemPC
EditPackages=OnlineSubsystemGameSpy
EditPackages=OnlineSubsystemLive
EditPackages=OnlineSubsystemSteamworks
then add your own line pointing to a folder named what ever you want but make sure it has a folder in it named Classes and it has the uc files you wnat to compile in it
ModEditPackages=MyTestProject
if you used that line then you are tellign udk you have a folder named
MyTestProject
located in your development/src folder and you want it to compile everything in there
Is there a way to follow a program's execution through DLL code in hex?
For example, I want to see what sections have just been read when I press a button. It has to work for x64 DLL's.
Thanks!
Yes you load the process into debugger and single step it.
Load the project in visual studio.
Press 'Play' or F5 to start the program in the debugger.
You will need to eventually halt execution sometime so you can start stepping through code or assembly code. You can do this by inserting a breakpoint, or breaking the execution by hitting the break command in the visual studio IDE.
Once halted, you can right click in the code view window, and select "Show Disassembly". Then it will show you the machine instructions.
Also in the watch window in the visual studio debugger, the right click pop up menu has an option to display all variables as hexidecimal. I'm beginning to prefer hex myself lately, because I can see invalid memory patterns easier.
You can use the tool at http://ircdb.org to log function calls arbitrary DLLs.
It's name is SocketSpy, because initially it was created for tracing winsock.dll only, but it does allow you to trace other dlls.
From http://fixunix.com/programmer/95098-tracing-library-dll-calls-win32.html
Use Option->Default Break Point List
Menu to add or remove soft breakpoints
from attached DLLs. Put soft
breakpoints only at function you need
to maximize execution time.
Soft breakpoint means that socketspy
does not stop at this breakpoint, only
log breakpoint information. Hard
breakpoint means that socketspy DOES
STOP at this breakpoint, and
Breakpoint dialog is opened. Specify
what calls should be captured ALL,
FROM EXE FILE or from DLLs (Combobox).
Specify log file File->Open Log File
menu if you want to save function
DLLs' calls into the text file, enable
logging (check box).
Then select a new or already action
process (Select Process button). The
tool can be used in NT/2000/XP only
Alternatively, there is StraceNT, which can trace arbitrary Dlls. It is available for free from http://www.intellectualheaven.com/default.asp?BH=projects&H=strace.htm
I've not used it, but I once stumble upon an Intel tool, which samples the context of the Instruction Pointer, and is able to use symbol files to convert IP to an actual function name... VTune maybe?
I guess there might be other such tools
UPDATE: aka. "statistical profilers"...
Debugging using IDE does not show you the assembly language equivalent of the execution of an IL instruction. You need to write your own hooks to a proper disassembler.