Program crashes when outside test environment - C++ - c++

I have a program that runs fantastically when run from inside Visual Studio 2010 Express but when built and taken out, it has problems. I have set up the external test environment the same as when it is run from within Visual Studio so that shouldn't be the problem. I want to attach it to the .exe to see where the crash is but I don't have the non-Express versions.
Any suggestions? Why would a program crash outside of the the VSC++ 2010 Express environment but run perfectly inside.
I would post code but it's a huge project, not a line that would cause an error.
Thank you so much for your time.

It's very difficult to know for certain without knowing what the crash is, but a couple of common issues that may cause this:
Environment variables not the same. Perhaps you are relying on something in vcvars32.bat in your test environment.
The PATH environment variable is not the same and your picking up some bad or incompatible DLL.
Your code is somehow dependant on the current working directory being the one when run from Visual Studio.

Wikipedia to the rescue?
Time can also be a factor in heisenbugs. Executing a program under control of a debugger can change the execution timing of the program as compared to normal execution. Time-sensitive bugs such as race conditions may not reproduce when the program is slowed down by single-stepping source lines in the debugger. This is particularly true when the behavior involves interaction with an entity not under the control of a debugger, such as when debugging network packet processing between two machines and only one is under debugger control.
Also, note that User32.dll slightly changes its behavior when under a debugger, in order to make debugging easier for you. That shouldn't change anything, though.

You could debug this using the freely available Debugger Tools for Windows. There's plenty of documentation and quick start guides available, especially the chm included in the install. In your case, you may want to try the following:
Make sure you have the PDBs for your app available somewhere on a share.
Attach to the running instance of the app: windbg -p <PID>. Note that you can also start the program under the context of the debugger by doing windbg -g foo.exe.
Repro the crash.
Change the symbol path to your symbols and the Microsoft public symbol server to get proper symbols for components: .sympath x:\YourPathToPDBs; SRV*x:\symbols*http://msdl.microsoft.com/download/symbols
Tell the debugger to reload symbols using your path: .reload
Get a callstack by hitting k in the debugger.
That's the barebones you need to figure out where it's crashing. You can then go deeper and try to analyze exactly why it's crashing by looking at the debugger chm or other resources on MSDN or Tess's blog. One useful command is dv to dump local variables for a particular frame. If the callstack doesn't give line numbers, type .lines and then hit k or kb.

You could surround all code in your Main function with a try catch block. When you catch an excepcion, write to a log file the stack trace.
Then run your exe and check the log file to know where your program is crashing.
PS: Don't forget to place the *.pdb file together with the exe file, otherwise you won't be able to get the stacktrace information.

I realise this question is a couple of years old, but I have been experiencing the same thing and came upon a possible culprit (the actual culprit in my case), which may help others who have this issue.
One important difference when running an application within Visual Studio and running it outside is the Current Working Directory ("CWD").
A typical directory structure for a Visual C++ Solution/Project is along these lines:
Solution <- the location of your solution file
Debug <- where the Debug executables end up
Release <- where the Release executables end up
Project <- the location of your project file
Debug <- where Debug intermediate files end up
Release <- where Release intermediate files end up
When you execute the application from within Studio, either with "Start Debugging" or "Start Without Debugging", the default CWD is the Project directory, so in this case Solution\Project.
However, when you execute outside by simply double-clicking the application, the CWD is the application directory (Solution\Debug for example).
If you are attempting to open a file from the current directory (which is what happens when you do std::ifstream ifstr("myfile.txt")), whether it succeeds depends on where you were when you started the application.

Related

How to debug program crashing before main()

I'm using QtCreator with the visual studio 2015 kit on windows 8.1 to build a program I developed and tested on Linux, on linux it works correctly, but on windows it's just crashing immediately, and I have no idea what to look for.
The only external libraries, aside from QT I'm using are opengl and glew, so I don't think it's those.
Is there anything that's known to work in GNU C++ but crash immediately in MSVC?
Usually this kind of crashes have absolutely nothing to do with your program. It's an external library linking issue. I had this issue recently with the OpenSplice DDS library. I linked to a library that caused a segmentation fault before anything started. I resolved the issue by linking the pre-compiled libraries 1-by-1, and check each if that fixes the program.
What I recommend you to do is: Remove the libraries and resources you're linking to gradually, until your program starts and prints "Hello world" from the first line of main().
Another way to go is, make a new empty program, and link the same resources you're using in your program. This is easier, as it doesn't involve modifying your program.
This is what I would do.
Start by rebuilding the entire solution or project from a clean state. Just in case this is just some weird dependency issue that resulted in something not getting recompiled. Never hurts.
As Neil said in the comments for the question, the crash is possibly coming from a global variable who's constructor runs before main or WinMain. Are you sure you don't have something declared as "static" or at global scope that might have a constructor?
Now do the following:
Open Visual Studio.
From the menu, select File->Open->Project/Solution...
When the file open dialog pops up, select the EXE produced by Qt
Creator. (That's right - you are opening the EXE as a project). This directory is typically one folder level above the Qt project (..\build-yourapp-Desktop_Qt_5_7_0_MSVC2015_32bit-Debug\debug)
Now press the green arrow to start debugging (menu->Debug->Start
Debugging). If all goes well, your program will fail early and
Now chances are high that the program is not going to run at all under Visual Studio because Qt Creator doesn't copy all the Qt*.dll binaries to your build directory. You'll get a bunch of dialogs popping up saying that "The program can't start because Qt5-XYZ.dll can't be found". This is easily fixed by updating your PATH environment in any of the following way to include your Qt5.x.0\5.x\msvc2015\bin folder to your PATH.
You add it from the command linke and then re-launch devenv.exe from the command line.
You can add it globally from Control Panel->System->Advanced. Then restart Visual Studio from the Windows desktop.
With the EXE debug project open from within Visual Studio, just right click on the project name (not parent solution) and a dialog will popup that allows you to edit startup settings. One of which is the Environment.
And that should do it. From there you can start the debugger on your EXE, set breakpoints as needed, and analyze the call stack on crash.
It's really easy: build all the libraries you use, including Qt, with debug information (those can be release builds as long as the PDB files are generated). Then run your application under a debugger (e.g. F5 under Qt Creator), and it will stop at the point of the crash.
The code that runs before main and is known to cause trouble will be the global object initialization: you're likely running into the static initialization order fiasco.
Another cause for the problem could be stackoverflow. In Linux, the stack size by default is usually 8 MB whereas in Windows it's just 1 MB.
Try to link with /STACK:8388608 switch. If it works, you might consider allocating more data on the heap and stay with the default stack size of 1 MB.

Dumping a stack trace from C++ (Windows) - fails to find symbols

I'm a developer of Windows desktop software, and from time to time our app crashes. In rare cases I'd like to get a customer to run a debug version of the app to send me a stack trace so I know where it crashed. I followed the instructions in here:
Windows C++ stack trace from a running app
...but while it works on my development machine, it doesn't work on any client machine or those of my colleagues, who don't have Visual Studio installed. So I presume that there's some .dll or something they need before it'll work. They're using the same .exe I'm using, i.e. the one I compiled in VC++ in debug mode.
After some painstaking "message window" debugging, I learnt it's failing in SymGetSymFromAddr64() - this returns FALSE. But when I walk the stack, this always returns FALSE or it returns garbage that doesn't make sense (random unrelated method names), as if it's the PC values which are invalid, not the mapping process. To reiterate, it's a debug mode .exe that produces a perfect symbolic stack trace on my development machine.
I did some research and found some mentions of "dbghelp.dll" and "imagehlp.dll" but I just ended up confused. "dbghelp.dll" ships with all versions of Windows, but with reduced functionality. There's some other things I could install, but it's a little scary to be installing some Windows "WDK" or "debug kits" which might overwrite important system .dll's or do god-knows-what to your computer.
So what I need to know is: "what's the simplest set of instructions I can give to these helper customers e.g. the minimum set of .dll's and where to stick them so that we can get proper symbolic information out of the stack traces when our program crashes?"
The most likely reason for failing to find the symbols is that the .pdb file cannot be found. Even if you generate a .exe in debug mode, the symbols are not in the .exe, they are in the .pdb file. Through a lot of empirical testing, it seems that the process has the pathname of the .pdb hardcoded in it, so if your clients don't have that file at that location, they won't necessarily find it. However, you can supply a "search path" to the SymInitialize() function - a folder or set of folders to use to search for the .pdb file.
In my configuration, I had an exe called "Edval.exe" and a .pdb called "DebugEdval.pdb". The process searches for "DebugEdval.pdb" in the search folders. This corresponds to what you've configured in "Properties > Linker > Debugging > Generate Program Database File".

What VS2010 C Project settings cause exes to require Compatibility Mode

I've been running and compiling a program on my Windows 7 64-bit machine for several months now, but recently I had to change several VC project settings of the static libs that it uses and now the generated executable file requires me to run it in "Windows XP Compatibility Mode".
Compiled on Windows7 64-bit machine with Visual Studio 2010 SP1
The program I am generating is being built in Win32, debug mode.
The static lib projects specify Target Machine /X86.
When I run the program from the debugger, it start up and runs, however if running via the windows icon, it requires XP compatibility mode.
When trying to start outside of the debugger the EXE shows up in task manager for a second then goes away.
I've tried using Microsoft Application Verifier on it, however I don't know what to look for in the output.
I've been unable to find any details on how to troubleshoot this issue so if anyone has any ways if finding what could be causing this recent Compatibility Mode requirement I'd love to hear how it was fixed.
I have the source/projects/solutions for the majority of the static libs that I link against, as well as the exe file generated, however some of the external dependencies I only have the .lib,.dll, and .h files for. This means I can change (most) of the project settings for the dependencies if neccessary, but I need to know which ones to look for.
Thanks
To be honest, don't be afraid to make another project and copy the code files, even if it's 5 projects. You need to cut the problem in half. If it works with the new projects then it's the project files, if not, it's the code. Making projects isn't that hard really, though I'm sure a source of much consternation and something people avoid. If its the projects you can diff the files and see what happened by process of elimination. If you are really worried, copy the entire solution to another folder; always make backups.
The problem is that you probably won't be able to hoist enough information up to us to get a meaningful answer unless get lucky, and all the answers will be shots in the dark.
So I'm goign to take this question as "this happens, what can I do about it". The strategy above will get you out of it, if this used to work before. This exercise will arm you for the future and will be more productive in the long term. Go look at UAC and manifest files, aka Vista+ difference tht dramatically changes load and run behaviour (Linker Commands, Vista Migration Guide) if you need one thing to look at, but try the above process.
----
Other generic things to try:
1) another machine
2) another install of VS
3) a simple project with one window that does nothing to prove everything else in your tool chain and environment is ok.
4) planting message boxes along the code path with different messages so you know where its crapping out.
5) turing on pdb in release and runnign outside of debugger. If craps out, then try debugging and see if still craps out, but you get to see where.
6) assume that your code is unstable and you were getting lucky when it used to work. (this one is no fun). Many times things work in debug and not in release due to mem layout being different. If your progam is large you can find creative ways to use #if's whatever to elimitate code from running while haivng the whole thing still load. You can find the code that causes the bad behaviour.
7) turn off UAC and error reporting if its on, see if changes.
8) go find the "run without debugging" menu button in Visual Studio, so you don't have to go run it with the icon. That's an accident waiting to happen, and eliminates one more environmental difference. It looks like the run with debugging button, but it's hollow, a plain green triangle. It's under debug menu set. My oppinion is that it has done more harm than good to not have that on the bar by default as its confused many many people to think launching wiht VS means always using the debugger.
and so on....

Renaming executable to game.exe causes 15 second delay when running -- STRANGE issue

This shakes my understanding of computers and operating systems on a level that makes me very uneasy. I have just spent about an hour entering different iterations of compile commands to g++ and in my exasperation I renamed the executable which kept having the delay from game.exe to gameg.exe and all of a sudden the problem vanished.
Here's some more background: I was noticing recently that when I ran my Eclipse unit test build, when I start with an SDL enabled test it would open the SDL window and freeze for about 20 seconds before being able to get the test started. On subsequent tests (which call SDL_Quit() and re-initialize SDL as part of the test process) this delay is not present. Now I have ascertained that ONLY when the executable is named exactly "game.exe" does this happen! I rename it to any other filename and it goes along running tests happily, initializing the SDL system within a second like it usually does. I had assumed before that there must be some kind of bug that was causing my Eclipse build to have this behavior which wasn't present in the makefile build, but it turns out if I take the eclipse build and rename its executable (the project folder it's in is called game hence game.exe) it doesn't exhibit the behavior.
Likewise I take my makefile build (whose filename is entropy_unittest_disp.exe fyi) and rename it to game.exe and it begins to do this. I rename it to game and it also does it (I am running from mingw's bash.. when not with .exe extension, explorer doesn't know it's an executable). However I changed it to game.exx and it worked normally.
WHAT IS THIS BLACK MAGIC? Why should a program function differently depending on its filename??? I do query argv[0] and i actually do it to print to console its value (for debug purposes) but unsurprisingly it just prints the program and its path. No logic is ever performed on it in my program.
I tried to run GDB to find out where it is freezing but once I press Ctrl+C GDB simply exits.
does anybody have any idea what this might be caused by? A virus?
edit: I downloaded this demo from this site: http://www.sdltutorials.com/sdl-opengl-tutorial-basics/
extracted it, renamed the file to game.exe, and yup, same thing happens. WHAT IS THIS? I'm going to try running dependency walker next to see if something's trying to hook into it.
I'm assuming you have either a AMD (ATI) or Nvidia graphics card with their official drivers.
Chances are, game.exe is the executable name for an actual game released and your drivers are running special optimizations for the "game" or loading the Crossfire or SLI profiles for this game. A quick Google search seems to tell me that Resident Evil 4 calls their executable "game.exe."
I recommend taking a look at this link for further details as to what may be happening:
http://www.kn00tcn.net/site/ati-catalyst-profiles/
not sure how to reply to steven's comment on the top answer, but regarding driver profiles, it's just a basic brute force check of .exe filenames
some games are guaranteed to be in a specific sub folder, so the driver looks for where the exe is located, such as '\team fortress 2\hl2.exe'
but since most games let you pick what folder name you're installing to, & a lot of the time the exe is in that same root folder, the drivers have no choice but to blindly assume gameX.exe is going to be gameX
a nice 'side effect' of this is you can force other game profiles on any game for troubleshooting purposes, or to try to enable CF/SLI scaling
so always try to make sure that your executable has an original name to know that the gfx driver isnt attempting to run 'optimizations' made exclusively for other games
Could this be due to Anti virus software running on your OS? Certain files are commonly used in Virus "Game.exe" could be one of them and hence additional care from OS / AV to ensure that it is safe
Test it in clean windows, without any extra software installation, if it work fine, then maybe you have some protection software like Anti-virus or sandbox , ... , if you have any of this software disable them, and test again
Check to see if game.exe is listed in the Image File Execution Options registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options. It can be used to launch a particular program as a debugger for an application with a particular name. (More info on Image File Execution Options)
An EXE will behave differently based on its name due to AppCompat Shimming. Check the loaded module list and see if there are a bunch of DLLs that start with "ac" loaded into your app.

How to debug a DYLIB in XCode?

I am an experienced Visual Studio developer who has recently taken on an OSX 10.6 project (a C++ server project with no UI).
I have been successfully debugging the application using the XCode debugger (setting breakpoints, etc.) for months, including debugging the source code for various static libraries that are linked into the final executable program.
However, tonight I was required to debug (with breakpoints) a DYLIB that is also built from our source code, but that is linked dynamically at runtime with the application (the name of the DYLIB is read from an .ini file by the main application).
Unfortunately, the usual method I use of debugging the application (right-clicking the custom executable and selecting "Debug with Breakpoints"), though it does successfully run the debugger and allow me to debug the application (along with its statically linked libraries), exhibits the following undesired behavior when I attempt to hit a breakpoint in the source code for the DYLIB:
-> The XCode debugger reports that the breakpoint was hit in the sense that I see the function and line number in the status bar at the bottom of the XCode windows (along with an indication that this is a gdb message), and the application halts execution. However, there is no stack trace, no variables, nothing - just a completely empty debugger window. The buttons to to "step over", "step into", etc, are disabled. No editor window appears in the debugger (and hence no visual indication that the debugger has stopped on the line indicated). Opening the file by hand does not reveal the debugger hitting the line.
Unfortunately, this is useless for me as far as my attempts to debug the DYLIB.
I have hunted far and wide tonight researching and attempting to find a way for the XCode debugger to successfully hit breakpoints in a meaningful way in the source code for this dynamically linked DYLIB. I have of course done a number of clean/rebuilds. I have made certain that "load symbols lazily" is unchecked and then cleaned/rebuilt. I have restarted, and I have also deleted the "build" directory and rebuilt. I also deleted the user-specific files in the .xcodeproj package. (Note also that I am of course building and running all code, including the DYLIB code, in Development mode with all optimizations off, and generating debug symbols for all.) However, my attempts have been unsuccessful. Nor can I find so much as a single mention of this problem on internet forums.
Any help in instructing me how to use XCode to successfully debug a DYLIB that is linked to my application would be appreciated.
Thanks,
Dan.
Update -
This problem is resolved. It was my lack of experience with OSX that caused me to fail to see this. Despite the fact that my DYLIB project was part of the same XCode project as the executable that calls it, and despite the fact that the DYLIB was built in the same directory as the executable, at runtime the debugged application was not accessing the DYLIB from this location. Instead, it was accessing it from a (different) install location. I have not as of this moment tracked down where the install location is "cooked" into the application, but by copying the final executable/DYLIB into the expected install location and creating a new custom executable that points to the executable in this location, debugging of both the DYLIB and the executable works.
Thanks,
Dan.