我的C ++应用程序仅在发布模式和Windows 7中崩溃

Question

I'm very frustrated with my app crash in Release Mode on Windows 7.

In the main function, I removed everything:

int main(int argc, char **argv, char **envp) {
    return (0);
}

But I do have a lot of directives, variables and functions defined outside of the main functions.

It only crashes in Release mode on Windows 7. Debug mode on Windows 7 is okay; Debug and Release modes on Windows XP are both okay.

Since I cannot debug, I don't what to do.

The error is:

Unhandled exception at 0x00dc21ca in MyApp.exe: 0xC0000005: Access violation reading location 0x8496a9bb.

Assembly line:

00DC21CA  mov         eax,dword ptr [edx+0Ch] 

This is so crazy, Please help.

Peter

PS: If I removed everything I defined outside the main, then it's okay.

PS:

char* AllocArgsMemory()
{
    return (char*)malloc(2); // works: return NULL
                             // So it seems the malloc has some problems
}

Answer 1

Check all the pointers you are using. They way your app crashes shows that you are dereferencing a null pointer or outside of a pre-allocated memory range(eg array). This is probably due to an uninitalized pointer or too large a subscription index.

It does not crash in debug mode, because in debug mode, the debugger usually inits uninitalized memory with a predefined value, eg 0xcccccccc, which does not happen in release mode.

Answer 2

Even if it is a release binary, you should create a full symbol file (.pdb) so you can have a decent callstack when your issue occurs. To get it : start any debugger (WinDbg, Visual Studio, etc.), setup it to stop on access violation exception, start you process with it, it should break when the exception occurs and give you a callstack. Remember that a debugger can run anything that can be executed ; even if you don't have links to source code and local variable values, you may have other usefull informations.

Hope it helps.

Answer 3

It sounds like it may be some of the built settings/properties. I don't have a lot to offer you (partially because the lack of information), but if its working in DEBUG mode in windows 7, like setting all the build settings/properties in RELEASE the same as DEBUG. If it works, you know it is an issue with a build setting