Reputation: 549
i am working on project developed in Qt, Windows, i use Qt Version 4.1.4 and VC6 IDE for compiling project, most of usage of product are on WindowsXp.
i frequently receive crash reports from testers and customers which does not have fix pattern and does not reproduce in my development environment.
so i come to the conclusion that i need to write a crash log from my program so that i always get the call stack when program is crashed.
in linux i know its possible to do it with some signal handling of segmentation fault. but how to do the same thing in windows/C++?
i tried to search on Google to find some ready made solution but without any luck.
Suggestion regarding any third party tools/libraries (free or licensed) are also accepted, but please do not suggest any method where i have to modify each function in my module to get log, because the project is huge and i can not afford that.
thanks in advance.
updates. I have attached StackWalker to my Code now (with bit of hassle of _MBCS & UNICODE) but atleast managed to attach it.
my main file looks like below,
class MyStackWalker : public StackWalker
{
FILE *sgLogFile;
public:
MyStackWalker() : StackWalker()
{
sgLogFile = fopen("ThisIsWhatIcallLog.log", "w");
}
MyStackWalker(DWORD dwProcessId, HANDLE hProcess) : StackWalker(dwProcessId, hProcess)
{
}
virtual void OnOutput(LPCSTR szText)
{
printf(szText);
fprintf(sgLogFile, "%s",szText);
fclose(sgLogFile);
StackWalker::OnOutput(szText);
}
};
LONG Win32FaultHandler(struct _EXCEPTION_POINTERS * ExInfo)
{
MyStackWalker sw;
sw.ShowCallstack();
return EXCEPTION_EXECUTE_HANDLER;
}
void InstallFaultHandler()
{
SetUnhandledExceptionFilter((LPTOP_LEVEL_EXCEPTION_FILTER) Win32FaultHandler);
}
But i get linker error now that symbols are not found,
main.obj : error LNK2001: unresolved external symbol "public: int __thiscall StackWalker::ShowCallstack(void *,struct _CONTEXT const *,int (__stdcall*)(void *,unsigned __int64,void *,int,unsigned long *,void *),void *)" (?ShowCallstack@StackWalker@@QAEHPAXPBU_CONTEXT@@P6GH0_K0HPAK0@Z0@Z)
main.obj : error LNK2001: unresolved external symbol "protected: virtual void __thiscall StackWalker::OnDbgHelpErr(char const *,int,unsigned __int64)(?OnDbgHelpErr@StackWalker@@MAEXPBDH_K@Z)
main.obj : error LNK2001: unresolved external symbol "protected: virtual void __thiscall StackWalker::OnLoadModule(char const *,char const *,unsigned __int64,int,int,char const *,char const *,unsigned __int64)" (?OnLoadModule@StackWalker@@MAEXPBD0_KHH001@Z)
main.obj : error LNK2001: unresolved external symbol "protected: virtual void __thiscall StackWalker::OnSymInit(char const *,int,char const *)" (?OnSymInit@StackWalker@@MAEXPBDH0@Z)
main.obj : error LNK2001: unresolved external symbol "public: __thiscall StackWalker::StackWalker(int,char const *,int,void *)" (??0StackWalker@@QAE@HPBDHPAX@Z)
release/Prog.exe : fatal error LNK1120: 5 unresolved externals
Error executing link.exe.
I have modified the StackWalker.cpp file to adapt to the UNICODE support, replaced "_tcscat_s" with "wcscat".
can you see, what's going wrong here?
Upvotes: 6
Views: 12934
Reputation: 1097
For cross-platform application Breakpad is probably better solution. But easy way for Windows -is to set unhandled exception handler via SetUnhandledExceptionFilter and write minidumps (with configuration you need) with WriteMiniDumpEx in handler.
Upvotes: 5
Reputation: 25710
Google Breakpad is a cross-platform crash-report library that seems useful.
See also the StackWalker for some windows-only code for getting a stack trace.
Also, installing an event filter by overriding QCoreApplication::notify
and catch all exceptions (including asyncronous ones such as stack overflow and access violation on Windows) is a good idea.
Upvotes: 6