Solving random crashes
I am getting random crashes on my C++ application, it may not crash for a month, and then crash 10 times in a hour, and sometimes it may crash on launch, while sometimes it may crash after several hours of operation (or not crash at all).
I use GCC on GNU/Linux and MingW on Windows, thus I can't use the Visual Studio JIT Debug...
I have no idea on how to proceed, looking randomly on the code would not work, the code is HUGE (and good part was not my work, also it has some good amount of legacy stuff on it), and I also don't have a clue on how to reproduce the crash.
EDIT: Lots of people mentioned that... how I make a core dump, minidump or whateverdump? This is the first time I need postmortem debugging.
EDIT2: Actually, DrMingw captured a call stack, no memory info... Unfortunately, the call stack don't helped me much, because near the end suddenly it go into some library (or something) that I don't have debug info, resulting only into some hexadecimal numbers... So I still need some decent dump that give more information (specially about what was in the memory... specifically, what was in the place that gave the "access violation" error)
Also, my application use Lua and Luabind, maybe the error is being caused by a .lua script, but I have no idea on how to debug that.
Answer
Try Valgrind (it's free, open-source):
The Valgrind distribution currently includes six production-quality tools: a memory error detector, two thread error detectors, a cache and branch-prediction profiler, a call-graph generating cache profiler, and a heap profiler. It also includes two experimental tools: a heap/stack/global array overrun detector, and a SimPoint basic block vector generator. It runs on the following platforms: X86/Linux, AMD64/Linux, PPC32/Linux, PPC64/Linux, and X86/Darwin (Mac OS X).
Valgrind Frequently Asked Questions
The Memcheck part of the package is probably the place to start:
Memcheck is a memory error detector. It can detect the following problems that are common in C and C++ programs.
Accessing memory you shouldn't, e.g. overrunning and underrunning heap blocks, overrunning the top of the stack, and accessing memory after it has been freed.
Using undefined values, i.e. values that have not been initialised, or that have been derived from other undefined values.
Incorrect freeing of heap memory, such as double-freeing heap blocks, or mismatched use of malloc/new/new[] versus free/delete/delete[]
Overlapping src and dst pointers in memcpy and related functions.
Memory leaks.